JP2019110343A - Film for protection film formation, sheet for protection film formation, methods for manufacturing work or workpieces, inspection method, and work and workpiece judged as acceptable items - Google Patents

Abstract

To provide: a film for protection film formation and a sheet for protection film formation, which can serve to protect the backside of a work such as a semiconductor wafer and a workpiece such as a semiconductor chip and which enable the formation of a protection film for improving the appearance thereof; methods for manufacturing a work or workpieces by use thereof; an inspection method by use thereof; and a work and a workpiece which are judged as acceptable items by the inspection method.SOLUTION: A film 1 for protection film formation has a transmittance of 15% or less to light having a wavelength of 550 nm, and a transmittance of 40% or more to light of a wavelength 1250 nm. A sheet 3 for protection film formation comprises: an adhesive sheet 4 arranged by laminating an adhesive layer 42 on one face of a base material 41; and a film 1 for protection film formation laminated on the side of the adhesive layer 42 of the adhesive sheet 4. A method for manufacturing a work or workpiece comprises the step of forming a protection film on the work or workpieces arranged by performing a division process on the work, while using the film 1 for protection film formation or sheet 3 for protection film formation.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a workpiece such as a semiconductor wafer or a workpiece obtained by processing the workpiece (for example, a semiconductor chip), a protective film-forming film and a protective film-forming sheet capable of forming a protective film, and a workpiece using these The present invention relates to a method of manufacturing a workpiece, an inspection method, and a workpiece and a workpiece that are determined to be non-defective products by the inspection method.

  In recent years, semiconductor devices have been manufactured by a mounting method called a face-down method. In this method, when a semiconductor chip having a circuit surface on which electrodes such as bumps are formed is mounted, the circuit surface side of the semiconductor chip is joined to a chip mounting portion such as a lead frame. Therefore, the back side of the semiconductor chip in which the circuit is not formed is exposed.

  Therefore, a protective film made of a hard organic material is often formed on the back surface side of the semiconductor chip in order to protect the semiconductor chip. This protective film is formed, for example, using a film for semiconductor back surface or a dicing tape-integrated wafer back surface protective film as disclosed in Patent Document 1.

  The protective film may also be used as a member for displaying information of a work (for example, a semiconductor wafer) or a workpiece (for example, a semiconductor chip) provided with the protective film. That is, by forming asperities on the surface of the protective film, printing may be performed in which information on the workpiece or the workpiece is visibly displayed. This printing process is usually performed by irradiating the surface of the protective film with a laser.

  In this regard, in the film for semiconductor back surface in Patent Document 1, the light transmittance at a wavelength of 532 nm or 1064 nm is 20% or less. This enables printing processing by laser light irradiation and prevents the semiconductor element from being adversely affected by the laser light.

Unexamined-Japanese-Patent No. 2012-28396

  On the other hand, a workpiece such as a semiconductor wafer may be subjected to so-called back grinding, in which the back surface opposite to the circuit formation surface is ground at a stage before protection, in which case Finally, grinding marks remain on the back surface of a workpiece such as a semiconductor chip. Then, for example, when visualizing a print applied to a protective film provided on a workpiece or a workpiece as described above, this grinding mark may also be visually recognized through the protective film, and the appearance may be impaired. There was a problem that there was. If the protective film is difficult to transmit, for example, light having a wavelength of 550 nm, which is approximately at the center of the visible light region, this grinding mark is hidden by the protective film (protective film-forming film) and hardly visible. That is, the protective film is also expected to have a function of improving the appearance of a work or a workpiece. However, the film for semiconductor back surface disclosed in Patent Document 1 does not necessarily have a sufficient function to improve such an appearance.

  The present invention has been made in view of the above circumstances, and protects a back surface of a workpiece such as a semiconductor wafer or a workpiece such as a semiconductor chip, and can form a protective film for improving the appearance. It is an object of the present invention to provide a forming film and a protective film forming sheet, a method of producing a work or a processed product using them, an inspection method using them, and a work and a processed product judged to be good by the inspection method. Do.

  When the content of the pigment in the film for protective film formation is larger than a predetermined value, the light transmittance of the protective film formation film and the protective film at a wavelength of 550 nm becomes remarkably low, and the above problem is caused It found out that it could solve, and completed the present invention.

In order to solve the above-mentioned subject, the present invention adopts the following composition.
[1]. A film for forming a protective film containing a pigment, wherein the content of the pigment is 2.6% by mass or more, the light transmittance at a wavelength of 550 nm is 15% or less, and the light transmittance at a wavelength of 1250 nm is 40% The film for protective film formation which is the above.
[2]. The film for protective film formation as described in [1] in which the said film for protective film formation contains a filler.
[3]. The 60 ° specular gloss Gs (60 °) defined in JIS Z8741: 1997 (ISO 2813: 1994) of the protective film formed from the protective film-forming film is 40% or more, [1] or [2] The film for protective film formation as described in these.
[4]. The film for protective film formation as described in any one of [1]-[3] whose light transmittance of wavelength 1064 nm is 50% or more.

[5]. The film for protective film formation as described in any one of [1]-[4] whose said pigment is an organic type pigment.
[6]. The film for protective film formation as described in any one of [1]-[5] in which the said film for protective film formation contains an epoxy resin.

[7]. The film for protective film formation as described in [6] in which the said epoxy resin contains an epoxy resin liquid at least at 23 degreeC and 1 atm.
[8]. An adhesive sheet comprising an adhesive layer laminated on one side of a substrate, and the protection according to any one of [1] to [7] laminated on the adhesive layer side of the adhesive sheet. A protective film forming sheet comprising a film forming film.

[9]. [1] to [7], or the work of forming a work by dividing the work using the film for forming a protection film according to any one of [1] to [7] or the sheet for forming a protection film according to [8] A method of manufacturing a work or a workpiece, wherein a protective film is formed on
[10]. Irradiating laser light in the infrared region so that the division processing is focused on the focal point set in the work, forming a modified layer inside the work, and forming the modified layer on the work [9] The method for producing a work or a processed product according to [9], which is processing in which a force is applied to divide the workpiece on which the modified layer is formed to obtain a plurality of strip-shaped bodies as a processed product.
[11]. The method for manufacturing a work or a work according to [9] or [10], wherein the work is a semiconductor wafer and the work is a semiconductor chip.
[12]. The inspection method which inspects via the said protective film using infrared rays about the workpiece | work or workpiece manufactured by the manufacturing method as described in any one of [9]-[11].
[13]. Work judged to be non-defective based on the inspection method described in [12].
[14]. A processed product determined to be non-defective based on the inspection method described in [12].

  According to the present invention, a film for forming a protective film and a sheet for forming a protective film capable of forming a protective film for protecting the back surface of a workpiece such as a semiconductor wafer or the like and a semiconductor chip and improving the appearance There are provided a method of manufacturing a work or a processed product using the same, an inspection method using the same, and a work and a processed product determined to be non-defective by the inspection method.

It is sectional drawing of the sheet | seat for protective film formation which concerns on one Embodiment of this invention. It is sectional drawing of the sheet | seat for protective film formation which concerns on other one Embodiment of this invention. It is sectional drawing of the sheet | seat for protective film formation which concerns on other one Embodiment of this invention. It is sectional drawing which shows the usage example of the sheet | seat for protective film formation which concerns on one Embodiment of this invention, specifically, a 1st laminated structure. It is imaging data of the printed protective film of the reference example 1. FIG. It is imaging data of the printed protective film of the reference example 3. FIG.

Hereinafter, embodiments of the present invention will be described.
[Film for protective film formation]
The film for protective film formation which concerns on this embodiment is for forming a protective film in the processed material obtained by processing a workpiece | work or the said workpiece | work. This protective film is composed of a protective film-forming film, preferably a cured protective film-forming film. Examples of the workpiece include a semiconductor wafer and the like. Examples of the workpiece obtained by processing the workpiece include a semiconductor chip, but the present invention is not limited thereto. When the work is a semiconductor wafer, the protective film is formed on the back side of the semiconductor wafer (the side on which an electrode such as a bump is not formed).

1. Material It is preferable that the film for protective film formation contains an unhardened curable adhesive. In this case, by laminating a workpiece such as a semiconductor wafer on the protective film-forming film and then curing the protective film-forming film, the protective film can be firmly adhered to the workpiece, and the protective film having durability is obtained. Can be formed on a chip or the like.

  It is preferable that the film for protective film formation has adhesiveness at normal temperature or exhibits adhesiveness by heating. Thereby, when superposing workpiece | works, such as a semiconductor wafer, on the film for protective film formation as mentioned above, both can be bonded. Therefore, positioning can be reliably performed before curing the protective film-forming film.

  It is preferable that the curable adhesive which comprises the film for protective film formation which has the above characteristics has a curable component and a binder polymer component. As the curable component, a thermosetting component, an energy ray curable component, or a mixture thereof can be used, but it is particularly preferable to use a thermosetting component. When the protective film-forming film has a light transmittance as described later, it is unsuitable for ultraviolet curing, and it is desirable that the film be thermosetting.

Examples of the thermosetting component include epoxy resin, phenol resin, melamine resin, urea resin, polyester resin, urethane resin, acrylic resin, polyimide resin, benzoxazine resin, and the like, and mixtures thereof. Among these, epoxy resins, phenol resins and mixtures thereof are preferably used.
A thermosetting component can be used individually by 1 type or in combination of 2 or more types.

  Epoxy resins have the property of being three-dimensional reticulated when heated and forming a strong film. As such an epoxy resin, conventionally known various epoxy resins are used, and may be referred to as “liquid epoxy resin” (hereinafter referred to as “liquid epoxy resin”) which is liquid (including highly viscous liquid) at 23 ° C. and 1 atm. And 23 ° C., 1 atm, which are solid (including semi-solid) epoxy resins (hereinafter sometimes referred to as “solid epoxy resins”). The liquid epoxy resin is specifically described as an epoxy resin having a viscosity of 40 Pa · s or less at 25 ° C. and 1 atm. In the present embodiment, although any one of these may be used, it is preferable to use at least a liquid epoxy resin. In this case, the epoxy resin may be made of only a liquid epoxy resin, or a liquid epoxy resin and a solid epoxy resin may be blended and used.

  As an epoxy resin liquid at 23 ° C. and 1 atm, one having a molecular weight of 300 to 500 is preferable, and one having a molecular weight of 330 to 400 is particularly preferable. Moreover, it is preferable that it is 50-5000 g / eq, and, as for the epoxy equivalent of liquid epoxy resin, it is preferable that it is 1002000 g / eq especially.

  On the other hand, as a solid epoxy resin at 23 ° C. and 1 atm, one having a molecular weight of 1000 to 6000 is preferable, and one having a molecular weight of 1400 to 4000 is particularly preferable. The softening point of the solid epoxy resin measured by the ring and ball method is preferably 50 to 150 ° C., and particularly preferably 65 to 130 ° C. Furthermore, the epoxy equivalent of the solid epoxy resin is preferably 50 to 5000 g / eq, and particularly preferably 100 to 2000 g / eq.

  Specific examples of the epoxy resin include glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenyl novolac and cresol novolac; glycidyl ethers of alcohols such as butanediol, polyethylene glycol and polypropylene glycol; phthalic acid Glycidyl ethers of carboxylic acids such as isophthalic acid and tetrahydrophthalic acid; glycidyl type or alkyl glycidyl type epoxy resins in which active hydrogen bonded to a nitrogen atom such as aniline isocyanurate is substituted with a glycidyl group; vinylcyclohexane diepoxide, 4-epoxycyclohexylmethyl-3,4-dicyclohexanecarboxylate, 2- (3,4-epoxy) cyclohexyl-5,5-spiro (3,4-epo) As the sheet) cyclohexane -m- dioxane, carbon in the molecule - epoxy is introduced by for example oxidation to carbon double bond include a so-called alicyclic epoxides. In addition, an epoxy resin having a biphenyl skeleton, a dicyclohexadiene skeleton, a dicyclopentadiene skeleton, a naphthalene skeleton or the like can also be used.

  Among these, bisphenol-based glycidyl-type epoxy resin, o-cresol novolac-type epoxy resin, phenol novolac-type epoxy resin, and dicyclopentadiene-type epoxy resin are preferably used. These epoxy resins can be used singly or in combination of two or more.

  When a liquid epoxy resin and a solid epoxy resin are blended and used, the ratio of the content of the liquid epoxy resin to the total content of the liquid epoxy resin and the solid epoxy resin is preferably 25% by mass or more and less than 100% by mass. It is more preferable that it is 30-90 mass%, and it is especially preferable that it is 35-80 mass%. When the content ratio of the liquid epoxy resin is 25% by mass or more, it becomes easy to control the mirror gloss of the protective film formed from the protective film-forming film to a high value, and the printing visibility of the protective film can be increased. It can be further enhanced. In the present specification, the “print visibility” of the protective film means the ease of visual recognition of the information based on the unevenness formed on the surface of the protective film by the printing process. In addition, it may be easy to control the light transmittance of a predetermined wavelength or the like to a preferable range described later. In this case, it is possible to receive further effects such as easy division of the work and easy infrared inspection of the workpiece. When a liquid epoxy resin and a solid epoxy resin are blended and used, it becomes easy to separate the processed product from the release sheet together with the protective film-forming sheet in the protective film-forming sheet described later.

  When using an epoxy resin, it is preferable to use a heat activated latent epoxy resin curing agent in combination as an auxiliary. The thermally activated latent epoxy resin curing agent is a type of curing agent that does not react with the epoxy resin at room temperature, is activated by heating above a certain temperature, and reacts with the epoxy resin. In the method of activating the thermally activated latent epoxy resin curing agent, a method of generating active species (anion, cation) by a chemical reaction by heating; stably dispersed in the epoxy resin at around room temperature, and the epoxy resin at high temperature There is a method of starting the curing reaction by dissolving and dissolving and starting the curing reaction; eluting at a high temperature with a curing agent of molecular sieve encapsulation type to start the curing reaction;

  Specific examples of the thermally activated latent epoxy resin curing agent include various onium salts, and high-melting point active hydrogen compounds such as dibasic acid dihydrazide compounds, dicyandiamide, amine adduct curing agents, and imidazole compounds. These heat-activated latent epoxy resin curing agents can be used alone or in combination of two or more. The heat-activated latent epoxy resin curing agent as described above is preferably 0.1 to 20 parts by mass, particularly preferably 0.2 to 10 parts by mass, more preferably 0. It is used in the ratio of 3 to 5 parts by mass.

  As a phenol resin, condensation products of phenols such as alkylphenols, polyhydric phenols, naphthols and the like with aldehydes are used without particular limitation. Specifically, phenol novolac resin, o-cresol novolac resin, p-cresol novolac resin, tert-butylphenol novolac resin, dicyclopentadiene cresol resin, polyparavinylphenol resin, bisphenol A novolac resin, or modified products thereof Etc. are used.

  The phenolic hydroxyl group contained in these phenolic resins can be easily added to the epoxy group of the above epoxy resin by heating to form a cured product having high impact resistance. For this reason, an epoxy resin and a phenol resin may be used in combination.

  The binder polymer component can give an appropriate tack to the protective film-forming film, and can improve the operability of the protective film-forming sheet. The weight average molecular weight of the binder polymer is preferably in the range of 50,000 to 2,000,000, more preferably 100,000 to 1.5,000,000, and particularly preferably 200,000 to 1,000,000. In addition, the weight average molecular weight (Mw) of the binder polymer component in this specification is a value of standard polystyrene conversion measured by the gel permeation chromatography method (GPC method), and the detail of a measuring method is the Example mentioned later. Show.

When the weight average molecular weight of the binder polymer is too low, the film formation of the film for forming a protective film becomes insufficient, and when too high, the compatibility with other components becomes worse, and as a result, uniform film formation is hindered. As such a binder polymer, for example, an acrylic polymer, a polyester resin, a phenoxy resin, a urethane resin, a silicone resin, a rubber polymer and the like are used, and in particular, an acrylic polymer is preferably used.
The binder polymers can be used alone or in combination of two or more.

As the acrylic polymer, for example, as a monomer component, a structural unit derived from (meth) acrylic acid alkyl ester, and a structural unit derived from (meth) acrylic acid derivative other than the (meth) acrylic acid alkyl ester And (meth) acrylic acid ester copolymers.
In the present specification, “(meth) acrylic acid” is a concept including both “acrylic acid” and “methacrylic acid”. The same applies to other similar terms.

  Examples of the (meth) acrylic acid alkyl ester include (meth) acrylic acid alkyl esters in which the alkyl group preferably has 1 to 18 carbon atoms, and examples thereof include methyl (meth) acrylate and ethyl (meth) acrylate , Propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, n-octyl (meth) acrylate, (meth) acrylate Isooctyl, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate ((meth) acrylate ) Lauryl acrylate), tridecyl (meth) acrylate, tetra tetra (meth) acrylate Syl (mystyl (meth) acrylate), pentadecyl (meth) acrylate, hexadecyl (meth) acrylate (palmityl (meth) acrylate), heptadecyl (meth) acrylate, octadecyl (meth) acrylate ((meth) acrylate (Meth) acrylic acid alkyl esters in which the alkyl group is linear, such as stearyl acrylate), isooctadecyl (meth) acrylate ((meth) acrylic isostearyl), isobornyl (meth) acrylate, (meth) acrylic And (meth) acrylic acid cycloalkyl ester such as dicyclopentanyl acid.

  Examples of the (meth) acrylic acid derivative include (meth) acrylic acid; glycidyl group-containing (meth) acrylic acid esters such as glycidyl (meth) acrylate; hydroxymethyl (meth) acrylate; (meth) acrylic acid 2 -A hydroxyl group-containing (meth) acrylic acid ester such as-hydroxyethyl, (meth) acrylic acid 2-hydroxypropyl, etc. can be mentioned.

  Among the above, when a glycidyl group is introduced into the acrylic polymer using glycidyl methacrylate or the like as a structural unit, the compatibility with the epoxy resin as the thermosetting component described above is improved, and the cured film for protective film formation is cured. The glass transition temperature (Tg) is increased, and the heat resistance is improved. Further, among the above, when a hydroxyl group is introduced into an acrylic polymer by using 2-hydroxyethyl acrylate or the like as a structural unit, adhesion to a work or adhesion physical property can be controlled.

  The weight average molecular weight of the polymer when an acrylic polymer is used as the binder polymer is preferably 100,000 or more, more preferably 150,000 to 1,000,000. The glass transition temperature of the acrylic polymer is preferably 20 ° C. or less, more preferably about −70 to 0 ° C., and has tackiness at normal temperature (23 ° C.).

  In the curable adhesive, the mixing ratio of the thermosetting component to the binder polymer component is preferably 50 to 1500 parts by mass, more preferably 70 to 500 parts by mass of the thermosetting component with respect to 100 parts by mass of the binder polymer component. 1000 parts by mass, more preferably 80 to 800 parts by mass. When the thermosetting component and the binder polymer component are compounded in such a proportion, suitable tackiness can be exhibited before curing, and the sticking operation can be stably performed, and after curing, protection excellent in film strength A membrane is obtained.

  The protective film-forming film preferably contains a filler. When the film for protective film formation contains a filler, while the hardness of the protective film after hardening can be maintained highly, moisture resistance can be improved. Furthermore, the thermal expansion coefficient of the protective film after curing can be made close to the thermal expansion coefficient of the semiconductor wafer, whereby the warpage of the semiconductor wafer during processing can be reduced.

Although the average particle diameter of the filler which the film for protective film formation contains is not specifically limited, It is preferable that it is 0.4 micrometer or less. When the average particle diameter of the filler is 0.4 μm or less, the specular gloss of the protective film formed from the protective film-forming film can be controlled, and the printing visibility of the protective film can be enhanced. In addition, it may be easy to control the light transmittance of a predetermined wavelength or the like to a preferable range described later. In this case, it is possible to receive further effects such as easy division of the work and easy infrared inspection of the workpiece.
The average particle diameter of the filler is more preferably 0.005 μm or more and 0.3 μm or less, still more preferably 0.005 μm or more and 0.2 μm or less, and particularly preferably 0.01 μm or more and 0.15 μm or less The thickness is preferably 0.01 μm or more and 0.1 μm or less. When the average particle size of the filler is excessively small, the filler is easily aggregated, so the average particle size of the filler is preferably 0.005 μm or more.

  In the present specification, the average particle diameter of less than 1 μm of the filler is determined by a dynamic light scattering method using a particle size distribution measuring apparatus (“Nanotrac Wave-UT 151” manufactured by Nikkiso Co., Ltd.) unless otherwise noted. It is a measured value. Further, the average particle diameter of 1 μm or more of the filler is a value measured by a laser diffraction / scattering method using a particle size distribution measuring apparatus (“Microtrac MT3000II” manufactured by Nikkiso Co., Ltd.) unless otherwise specified.

  The specific type of the filler is not limited as long as the above average particle diameter condition is satisfied. Examples of the filler include silica such as crystalline silica, fused silica, synthetic silica and the like, and inorganic filler such as alumina and a glass balloon. Among these, silica is preferable as the filler, and synthetic silica is more preferable. In particular, synthetic silica of a type in which a source of α rays which causes malfunction of a semiconductor device is removed as much as possible is optimum. The shape of the filler may, for example, be spherical, needle-like, or indeterminate, but it is preferably spherical, and particularly preferably spherical. When the filler is spherical or spherical, irregular reflection of light is unlikely to occur, and control of the spectrum profile of light transmittance of the protective film-forming film is facilitated.

  Moreover, as a filler added to the film for protective film formation, the functional filler is also mentioned other than the said inorganic filler. As the functional filler, for example, a conductive filler in which gold, silver, copper, nickel, aluminum, stainless steel, carbon, ceramic, nickel, aluminum or the like is coated with silver for the purpose of imparting conductivity after die bonding And heat conductive fillers such as metal materials such as gold, silver, copper, nickel, aluminum, stainless steel, silicon, germanium, and alloys thereof for the purpose of imparting thermal conductivity.

  The compounding amount (content) of the filler in the protective film-forming film is preferably 10% by mass to 80% by mass, more preferably 20% by mass to 70% by mass, and 30% by mass or more The content is more preferably 65% by mass or less, particularly preferably 40% by mass or more and 60% by mass or less, and most preferably 50% by mass or more and 60% by mass or less. The effect of improving the external appearance of a workpiece | work or a workpiece becomes high as the compounding quantity of a filler is 10 mass% or more. Moreover, it may be easy to control the light transmittance of a predetermined wavelength of the protective film-forming film in a preferable range described later. On the other hand, when the compounding amount of the filler is 80% by mass or less, it becomes easy to enhance the printing visibility of the protective film, or the light transmittance of a predetermined wavelength of the film for protective film formation is in the preferable range described later. It becomes easy to control.

  The fillers can be used alone or in combination of two or more.

The protective film-forming film contains a pigment.
As the pigment, for example, known pigments such as inorganic pigments and organic pigments can be used, but from the viewpoint of enhancing the controllability of light transmittance, organic pigments are preferable. The pigment is preferable from the viewpoint of high chemical stability (specifically, difficulty in elution, difficulty in occurrence of color transfer, and little change with time).

  The film for protective film formation may contain coloring agents other than pigments, such as an organic type dye, other than a pigment. The organic dye is preferable from the viewpoint of enhancing the controllability of the light transmittance, like the organic pigment.

  Examples of organic pigments and organic dyes that are organic colorants include aminium dyes, cyanine dyes, merocyanine dyes, croconium dyes, squalium dyes, azulenium dyes, polymethine dyes, naphthoquinone dyes, Pyrylium dyes, phthalocyanine dyes, naphthalocyanine dyes, naphtholactam dyes, azo dyes, condensed azo dyes, indigo dyes, perinone dyes, perylene dyes, perylene dyes, dioxazine dyes, quinacridone dyes, isoindolinone dyes Dye, Quinophthalone Dye, Pyrrole Dye, Thioindigo Dye, Metal Complex Dye (Metal Complex Dye), Dithiol Metal Complex Dye, Indolephenol Dye, Triarylmethane Dye, Anthraquinone Dye, Dioxazine Dye, Naphthol Dye, a Methine dyes, benzimidazolone pigments, pyranthrone pigments and threne color, and the like.

  The organic colorant (organic pigment and organic dye) may be composed of one type of material or may be composed of a plurality of types of materials. From the viewpoint of making it easy to enhance the printing visibility of the protective film formed from the protective film-forming film, and easy to control the light transmittance of a predetermined wavelength of the protective film-forming film within the preferable range described later It is preferable that the coloring agent which the film for protective film formation which concerns on this embodiment contains from a multiple viewpoint is comprised from multiple viewpoints.

  For example, in the case of organic pigments, isoindolinone pigments that are yellow pigments, phthalocyanine pigments that are blue pigments, and diketopyrrolopyrroles that are red pigments are blended in appropriate proportions. If it does, it may become easy to control the light transmittance of the predetermined wavelength of the film for protective film formation in the preferable range mentioned later.

  Examples of inorganic pigments include carbon black, cobalt dyes, iron dyes, chromium dyes, titanium dyes, vanadium dyes, zirconium dyes, molybdenum dyes, ruthenium dyes, platinum dyes, ITO (indium Tin oxide dyes, ATO (antimony tin oxide) dyes, etc. may be mentioned.

  The content of the pigment in the film for protective film formation is 2.6% by mass or more, preferably 2.6% by mass or more and 5.5% by mass or less, and 2.6% by mass or more and 5.0% by mass It is more preferable that it is the following, It is more preferable that it is 2.6 to 4.5 mass%, It is especially preferable that it is 2.6 to 4.0 mass%.

  On the other hand, the content of the colorant other than the pigment in the film for protective film formation is not particularly limited as long as the effect of the present invention is not impaired, but usually, it is preferably 0.3% by mass or less. It is more preferable that the content is less than or equal to mass%, further preferably, less than or equal to 0.05 mass%, and it is particularly preferable that the film for forming a protective film does not contain a colorant other than the pigment. .

  The average particle size of the colorant is not limited. The average particle diameter of the coloring agent is preferably set to enhance the printing visibility of the protective film formed of the protective film-forming film, and the light transmittance of a predetermined wavelength of the protective film-forming film will be described later. It is further preferable to set so as to facilitate control to a preferable range. When the average particle size of the colorant is excessively large, it may be difficult to increase the light transmittance regardless of the wavelength. If the average particle size of the colorant is too small, the possibility of secondary problems such as difficulty in obtaining such colorant and reduction in handleability increases. Therefore, the average particle diameter of the colorant is preferably 1 to 500 nm, more preferably 3 to 100 nm, and still more preferably 5 to 50 nm. In addition, let the average particle diameter of the coloring agent in this specification be a value measured by a dynamic light scattering method using a particle size distribution measuring apparatus (Nanotrac Wave-UT 151, manufactured by Nikkiso Co., Ltd.).

  The colorants (pigments, dyes) can be used alone or in combination of two or more.

The film for protective film formation may contain a coupling agent. By containing the coupling agent, after curing of the protective film-forming film, it is possible to improve the adhesion and adhesion between the protective film and the work without impairing the heat resistance of the protective film, and at the same time the water resistance. (Mod heat resistance) can be improved. As a coupling agent, a silane coupling agent is preferable in view of its versatility and cost merit.
The coupling agents can be used alone or in combination of two or more.

As a silane coupling agent, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- (methacryloxy) Propyl) trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-6- (aminoethyl) -γ-aminopropylmethyldiethoxysilane, N -Phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfane, methyltri Methoxysilane Methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazole silane and the like.
The silane coupling agent can be used singly or in combination of two or more.

The film for protective film formation may contain a crosslinking agent such as an organic polyvalent isocyanate compound, an organic polyvalent imine compound, and an organic metal chelate compound in order to adjust the cohesion before curing. Moreover, the film for protective film formation may contain an antistatic agent in order to suppress static electricity and to improve the reliability of a chip | tip. Furthermore, the film for protective film formation may contain flame retardants, such as a phosphoric acid compound, a brominated compound, a phosphorus compound, etc., in order to improve the flame-retardant performance of a protective film and to improve the reliability as a package.
The crosslinking agent, the antistatic agent and the flame retardant may be used alone or in combination of two or more.

  The thickness of the protective film is preferably 3 to 300 μm, more preferably 5 to 200 μm, and most preferably 7 to 100 μm, in order to effectively exhibit the function as a protective film. More preferable.

2. Physical Properties (1) Transmittance The protective film-forming film according to this embodiment has a light transmittance of 15% or less at a wavelength of 550 nm. The light transmittance in the present specification is a value measured without using an integrating sphere at any wavelength (for example, wavelengths 1064 nm and 1250 nm described later), and a spectrophotometer is used as a measuring instrument.

  In the case where the workpiece is a semiconductor chip, for example, grinding marks resulting from the back grinding process applied to the semiconductor wafer remain on the back surface of the semiconductor chip. When the light transmittance at a wavelength of 550 nm, which is substantially at the center of the visible light region, is 15% or less as described above, the protective film-forming film hardly transmits visible light. Therefore, the above-mentioned grinding marks are concealed by the protective film-forming film (protective film) and hardly visible visually. As a result, the appearance of a workpiece such as a semiconductor wafer or a workpiece such as a semiconductor chip becomes excellent.

  From the viewpoint of the above-mentioned grinding trace concealability, the light transmittance at a wavelength of 550 nm of the film for protective film formation is preferably 14.5% or less, more preferably 14% or less, and 13.5% or less It is further preferred that In addition, the lower limit value of the light transmittance of wavelength 550 nm of the film for protective film formation is not specifically limited from a viewpoint of grinding mark concealability. On the other hand, if the light transmittance at a wavelength of 550 nm is excessively reduced, for example, it may be difficult to set the light transmittance at a wavelength of 1064 nm to be 50% or more, for example, The lower limit value of is preferably about 0.1%, and more preferably about 0.5%.

  The film for protective film formation which concerns on this embodiment becomes easy [the division | segmentation process by modification layer destructive type | formula division / division | segmentation / division | segmentation division | segmentation] demonstrated that the light transmittance of wavelength 1064 nm is 50% or more. In the present specification, this ease of processing by the modified layer fracture-type tension division is also referred to as "modified fracture-processability".

  Conventionally, when manufacturing a workpiece made of a piece such as a semiconductor chip from a work such as a semiconductor wafer, conventionally, the piece is cut by cutting the work with a rotary blade while spraying a liquid for cleaning and the like on the piece It is common that division processing by blade dicing is performed. However, in recent years, division processing using a modified layer fracture-type tension division that can be divided into pieces in a dry manner has been adopted. In such division processing, a laser beam in the infrared region is irradiated so as to be focused on a focal point set in the workpiece, thereby forming a modified layer inside the workpiece, and the workpiece on which the modified layer is formed Force is applied to divide the work on which the modified layer is formed to obtain a plurality of strip-like bodies as a processed material. A specific example of such a division processing method is to use a laser having a large opening (NA) so that a modified layer is preliminarily formed inside the workpiece while minimizing damage to the vicinity of the surface of the workpiece. After irradiation with light, a force is applied to the workpiece in an expanding step or the like to obtain a strip as a workpiece. The stealth dicing (registered trademark) method advocated by Hamamatsu Photonics K. K., etc. may be mentioned as a method for producing a chip by a modified layer fracture-type tension division.

  The light transmittance at a wavelength of 1064 nm of the protective film-forming film according to the present embodiment is more preferably 55% or more, further preferably 60% or more, from the viewpoint of enhancing the modification destruction processability. It is particularly preferable that it is 65% or more. The upper limit of the light transmittance at a wavelength of 1064 nm of the film for protective film formation according to the present embodiment is not limited from the viewpoint of enhancing the modification fracture processability, but for example, it is preferably 85%.

  It is preferable that the light transmittance of wavelength 1250 nm of the film for protective film formation which concerns on this embodiment is 40% or more. When the light transmittance at a wavelength of 1250 nm of the film for protective film formation is 40% or more, the infrared inspection described below becomes easy.

  In semiconductor chips and the like obtained by dicing a semiconductor wafer, cracks generated by stress generated during processing, processing tools such as rotary blades, and other parts (including semiconductor chips and the like) in workpieces such as semiconductor wafers In some cases, the chip may have a chipping or the like generated by a collision or the like (these may be generically referred to as "crack or the like" in the present specification). However, depending on the light transmittance of the protective film formed, cracks and the like generated on the protective film side of the semiconductor chip can not be visually detected. The semiconductor chip in which the crack etc. which can not be overlooked generate | occur | produces will reduce a product yield. As the size of the semiconductor chip becomes smaller, the size of such a crack which can not be overlooked tends to be smaller.

  On the other hand, when the light transmittance at a wavelength of 1250 nm of the film for protective film formation is 40% or more as described above, the transmittance of infrared light of the film for protective film formation is particularly good, and the film for protective film formation An infrared inspection can be performed in which infrared light is irradiated from the side (or the protective film formed by the protective film-forming film). Thus, cracks and the like in the processed product such as a semiconductor chip can be found through the protective film-forming film (protective film), and the product yield can be improved.

  From the viewpoint of enhancing the infrared transmittance of the film for protective film formation to facilitate the above-mentioned inspection, the light transmittance of the film for protective film formation according to the present embodiment at a wavelength of 1250 nm is 45% or more It is preferably 50% or more, more preferably 55% or more, and most preferably 60% or more. The upper limit of the light transmittance at a wavelength of 1250 nm of the film for protective film formation according to the present embodiment is not particularly limited. When using a workpiece (such as a semiconductor chip) on which a protective film is formed, by setting the light transmittance of the film for protective film formation at a wavelength of 1250 nm to 90% or less, false errors in workpieces susceptible to external infrared rays It can prevent operation.

  Here, although the film for protective film formation concerning this embodiment may consist of a single layer, and may consist of a plurality of layers, the above-mentioned easiness of control of light transmittance and It is preferable to consist of a single layer from the viewpoint of manufacturing cost. In the case where the protective film-forming film is composed of a plurality of layers, it is preferable to satisfy the above-mentioned condition of light transmittance as the whole of the plurality of layers from the viewpoint of easiness of control of light transmittance.

  In addition, when the film for protective film formation becomes an unhardened curable adhesive, the light transmittance of the film for protective film formation hardly changes whether it is before hardening or after hardening. Therefore, when the protective film-forming film before curing satisfies the condition of light transmittance for any of the above wavelengths, the protective film obtained by curing the protective film-forming film is also the light transmittance of the wavelength Can meet the requirements of

(2) 60 degree specular gloss Gs (60 °)
The protective film formed from the protective film-forming film according to the present embodiment is 60 degrees as defined in JIS Z8741: 1997 (ISO 2813: 1994) from the viewpoint of facilitating improvement in the printing visibility of the protective film. The specular gloss Gs (60 °) is preferably 40% or more. In the present specification, the 60 ° specular gloss Gs (60 °) means a value measured using a gloss meter “VG 2000” manufactured by Nippon Denshoku Kogyo Co., Ltd. From the viewpoint of more stably improving the printing visibility of the protective film, the 60 ° specular gloss Gs (60 °) of the protective film is preferably 50% or more, more preferably 60% or more, and 70% It is more preferable that it is the above, and it is especially preferable that it is 80% or more. From the viewpoint of enhancing the printing visibility of the protective film, the upper limit value of the 60 ° specular gloss Gs (60 °) of the protective film is not particularly limited, but is preferably 95%, for example.

[Protective film forming sheet 2]
FIG. 1 is a cross-sectional view of a protective film-forming sheet according to an embodiment of the present invention. As shown in FIG. 1, the protective film-forming sheet 2 according to the present embodiment is laminated on the protective film-forming film 1 and one surface of the protective film-forming film 1 (the lower surface in FIG. 1). And a release sheet 21. However, the peeling sheet 21 is peeled at the time of use of the sheet | seat 2 for protective film formation.

The release sheet 21 protects the film 1 for forming a protective film until the sheet 2 for forming a protective film is used, and may not be necessarily required.
The configuration of the release sheet 21 is arbitrary, and an example is shown in which the plastic film having release property to the film 1 for protective film formation and the plastic film are release-treated with a release agent or the like. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. As the release agent, those of silicone type, fluorine type, long chain alkyl type and the like can be used, but among these, silicone type release agents which can obtain stable performance at low cost are preferable.
Although there is no restriction | limiting in particular about the thickness of the peeling sheet 21, Usually, it is about 20-250 micrometers.

  The release sheet 21 as described above may be laminated also on the other surface (upper surface in FIG. 1) of the protective film-forming film 1. In this case, it is preferable to increase the peel strength of one release sheet 21 to make a heavy release type release sheet, and reduce the release force of the other release sheet 21 to form a light release type release sheet.

  In order to manufacture the protective film-forming sheet 2 according to the present embodiment, the release surface of the release sheet 21 (a surface having release properties; usually a surface to which release processing has been applied, but is not limited thereto) A protective film-forming film 1 is formed. Specifically, a coating agent for a film for protective film formation, which contains a curable adhesive constituting the film for protective film formation 1 and optionally a solvent, is prepared, and a roll coater, a knife coater, a roll knife coater The protective film-forming film 1 is formed by applying and drying on the release surface of the release sheet 21 by a coating machine such as an air knife coater, a die coater, a bar coater, a gravure coater, a curtain coater or the like.

The method of manufacturing the chip | tip in which the protective film was formed from the semiconductor wafer as a workpiece | work as an example using the sheet | seat 2 for protective film formation which concerns on this embodiment is demonstrated below.
First, the protective film-forming film 1 of the protective film-forming sheet 2 is attached to the back surface of the semiconductor wafer having a circuit formed on the surface and back-grind processed. At this time, the film 1 for forming a protective film may be heated to exhibit adhesiveness as desired.

  Subsequently, the peeling sheet 21 is peeled from the film 1 for protective film formation. Thereafter, the protective film-forming film 1 is cured to form a protective film, and a semiconductor wafer on which the protective film is formed is obtained. When the protective film-forming film 1 is a thermosetting adhesive, the protective film-forming film 1 may be heated at a predetermined temperature for an appropriate time. Curing of the protective film-forming film 1 may be performed after any of laser printing and division processing described below.

  When a semiconductor wafer with a protective film is obtained as described above, the protective film is irradiated with a laser beam, if desired, to perform laser printing. Laser printing may be performed after division processing described below.

  The division processing may be blade dicing or modified layer fracture-type tension division. In the latter case, the semiconductor wafer on which the printed protective film is formed is placed in the laser irradiation apparatus for division processing, and after detecting the position of the surface of the semiconductor wafer covered with the protective film, the processing laser To form a modified layer in the semiconductor wafer. When the protective film-forming film according to the present embodiment contains a filler, the protective film-forming film and the protective film transmit this processing laser when the average particle diameter of the filler is, for example, 0.4 μm or less. The modified layer is easily formed in the semiconductor wafer.

  A dicing sheet is attached to the surface on the protective film side of the laminate including the semiconductor wafer and the protective film in which the modified layer thus obtained is formed. Then, a force (a tensile force in the main surface in the inward direction) is applied to the semiconductor wafer 6 with a protective film by performing an expanding step of expanding the dicing sheet. As a result, the above-described laminate to be attached to the dicing sheet is divided to obtain a chip on which a protective film is formed. Thereafter, using a pickup device, the chip on which the protective film is formed is picked up from the dicing sheet.

  A processed product such as a chip on which the protective film obtained as described above is formed is excellent in print visibility depending on the configuration of the protective film, and the processed product such as a chip is infrared rays through the protective film. It is easy to inspect and it is easy to find a workpiece having a crack or the like. Furthermore, the infrared inspection through the protective film-forming film or the protective film may be facilitated for the workpiece before the division processing is performed. Thus, using the protective film-forming sheet 2 according to the present embodiment, a workpiece or a workpiece is judged as non-defective based on an inspection method of performing inspection (infrared inspection) through the protective film using infrared light. It is possible to easily obtain the workpieces and the processed products.

[Protective film forming sheet 3, 3A]
FIG. 2 is a cross-sectional view of a protective film-forming sheet according to another embodiment of the present invention. As shown in FIG. 2, the protective film-forming sheet 3 according to the present embodiment includes a pressure-sensitive adhesive sheet 4 formed by laminating the pressure-sensitive adhesive layer 42 on one surface side of a substrate 41, and a pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet 4. A protective film-forming film 1 laminated on the side 42 and a jig pressure-sensitive adhesive layer 5 laminated on the peripheral edge of the protective film-forming film 1 opposite to the adhesive sheet 4 are configured. The jig pressure-sensitive adhesive layer 5 is a layer for bonding the protective film forming sheet 3 to a jig such as a ring frame.

  The sheet 3 for forming a protective film is used to form a protective film on a workpiece obtained by processing the work or the work while being stuck to the work to hold the work when the work is processed. Be This protective film is composed of a protective film-forming film 1, preferably a cured protective film-forming film 1.

  For example, the protective film forming sheet 3 is used to hold a semiconductor wafer at the time of dicing processing of a semiconductor wafer as a work and to form a protective film on a semiconductor chip obtained by dicing, but is limited thereto It is not a thing. The adhesive sheet 4 of the protective film forming sheet 3 in this case is usually referred to as a dicing sheet.

1. Pressure-Sensitive Adhesive Sheet The pressure-sensitive adhesive sheet 4 of the protective film-forming sheet 3 according to this embodiment is configured to include a base 41 and a pressure-sensitive adhesive layer 42 stacked on one surface of the base 41.

1-1. The base material 41 of the pressure-sensitive adhesive sheet 4 is not particularly limited as long as it is suitable for processing of a work, for example, dicing and expanding of a semiconductor wafer, and usually, a resin material is mainly used. It is composed of a film (hereinafter referred to as "resin film").

  Specific examples of resin films include polyethylene films such as low density polyethylene (LDPE) films, linear low density polyethylene (LLDPE) films, high density polyethylene (HDPE) films, polypropylene films, polybutene films, polybutadiene films, polymethylpentene films , Polyolefin-based films such as ethylene-norbornene copolymer film and norbornene resin film; ethylene-vinyl acetate copolymer film, ethylene- (meth) acrylic acid copolymer film, ethylene- (meth) acrylic acid ester copolymer Ethylene copolymer films such as films; polyvinyl chloride films such as polyvinyl chloride film, vinyl chloride copolymer film; polyethylene terephthalate film, polybutylene tere Polyester film of tallate films; polyurethane film; polyimide film; polystyrene films; polycarbonate films; fluororesin films and the like. In addition, modified films such as these crosslinked films and ionomer films are also used. The above-mentioned substrate 41 may be a film made of one of these, or may be a laminated film in which two or more of these are combined.

  Among the above, from the viewpoint of environmental safety, cost and the like, the resin film is preferably a polyolefin film, and among them, a polypropylene film having excellent heat resistance is preferable. If it is a polypropylene film, heat resistance can be provided to the substrate 41 without impairing the expandability of the pressure-sensitive adhesive sheet 4 and the pick-up aptitude of chips. With the heat resistance of the base material 41, the occurrence of the slack of the adhesive sheet 4 is suppressed even when the film 1 for protective film formation is thermally cured in a state where the protective film forming sheet 3 is attached to a work. be able to.

  In order to improve the adhesion with the pressure-sensitive adhesive layer 42 laminated on the surface of the substrate 41, surface treatment or primer treatment may be performed on one side or both sides if desired, by one side or both sides. it can. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet process), flame treatment, hot air treatment, ozone, ultraviolet ray irradiation treatment and the like, and examples of the surface roughening method include sand blast method And thermal spray treatment methods.

  The base material 41 may contain various additives such as a colorant, a flame retardant, a plasticizer, an antistatic agent, a lubricant, and a filler in the resin film.

  The thickness of the substrate 41 is not particularly limited as long as it can function properly in each process in which the protective film forming sheet 3 is used. It is preferably in the range of 20 to 450 μm, more preferably 25 to 400 μm, and particularly preferably 50 to 350 μm.

  The breaking elongation of the base material 41 of the pressure-sensitive adhesive sheet 4 in the present embodiment is preferably 100% or more as a value measured at 23 ° C. and a relative humidity of 50%, and particularly preferably 200 to 1000%. . Here, the breaking elongation is an elongation percentage of the length of the test piece at the time of breaking the test piece with respect to the original length in a tensile test based on JIS K7161: 1994 (ISO 527-11993). The above-mentioned base material 41 having a breaking elongation of 100% or more is not easily broken in the expanding step, and the chip formed by cutting the work is easily separated.

  The tensile stress at 25% strain of the substrate 41 of the pressure-sensitive adhesive sheet 4 in the present embodiment is preferably 5 to 15 N / 10 mm, and the maximum tensile stress is preferably 15 to 50 MPa. Here, the tensile stress at 25% strain and the maximum tensile stress are measured by a test according to JIS K7161: 1994. When a workpiece is attached to the film 1 for protective film formation with a tensile stress of 5 N / 10 mm or more and a maximum tensile stress of 15 MPa or more at 25% strain, the substrate 2 is fixed to a frame such as a ring frame. It is possible to suppress the occurrence of slack and prevent the occurrence of transport errors. On the other hand, when the 25% strain tensile stress is 15 N / 10 mm or less and the maximum tensile stress is 50 MPa or less, peeling of the protective film-forming film 1 itself from the ring frame during the expanding step is suppressed. The above-mentioned breaking elongation, tensile stress at 25% strain, and maximum tensile stress refer to values measured in the lengthwise direction of the raw fabric of the substrate 41.

1-2. Pressure-sensitive adhesive layer The pressure-sensitive adhesive layer 42 included in the pressure-sensitive adhesive sheet 4 of the protective film-forming sheet 3 according to this embodiment may be made of a non-energy ray-curable pressure-sensitive adhesive or made of an energy ray-curable pressure-sensitive adhesive May be As the non-energy ray curable adhesive, those having desired adhesive strength and removability are preferable. For example, acrylic adhesive, rubber adhesive, silicone adhesive, urethane adhesive, polyester adhesive And polyvinyl ether-based pressure-sensitive adhesives can be used. Among these, an acrylic pressure-sensitive adhesive which is high in adhesion to the protective film-forming film 1 and which can effectively suppress dropping of a work or a workpiece in a dicing step or the like is preferable.

  On the other hand, the energy ray-curable pressure-sensitive adhesive is reduced in adhesive force by energy ray irradiation, so when it is desired to separate the work or the processed product from the pressure-sensitive adhesive sheet 4, energy ray irradiation makes them easily separated. be able to.

  When the pressure-sensitive adhesive layer 42 is formed of an energy ray-curable pressure-sensitive adhesive, the pressure-sensitive adhesive layer 42 in the protective film-forming sheet 3 is preferably cured. A material obtained by curing an energy ray-curable adhesive usually has a high elastic modulus and high surface smoothness, so the protective film-forming film 3 in contact with a cured portion made of such a material is cured and protected. When a film is formed, the surface in contact with the hardened portion of the protective film has high smoothness (gloss), and is excellent in appearance as a protective film of a chip. In addition, when laser printing is performed on a protective film having high surface smoothness, the visibility of the printing is improved.

  The energy ray-curable pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 42 may be one having an energy ray-curable polymer as a main component, or a polymer having no energy ray-curable property and an energy ray-curable polymer. It may be based on a mixture with a functional monomer and / or an oligomer.

  The case where the energy ray-curable pressure-sensitive adhesive contains a polymer having energy ray-curable properties as a main component will be described below.

  A polymer having energy ray curability is a (meth) acrylic acid ester (co) polymer (a) (hereinafter referred to as “energy ray,” in which a functional group (energy ray curable group) having energy ray curability is introduced in a side chain It is preferable that it is a curable polymer (a). The energy ray-curable polymer (a) comprises a (meth) acrylic copolymer (a1) having a functional group-containing monomer unit and an unsaturated group-containing compound (a2) having a substituent bonded to the functional group And those obtained by reacting

  The acrylic copolymer (a1) is preferably, for example, one composed of a structural unit derived from a functional group-containing monomer and a structural unit derived from a (meth) acrylic acid ester monomer or a derivative thereof.

  The functional group-containing monomer to be a constituent unit of the acrylic copolymer (a1) has, for example, a polymerizable double bond, and a functional group such as a hydroxyl group, an amino group, a substituted amino group or an epoxy group in the molecule. It is preferable that it is a monomer which it has.

  More specific examples of the functional group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and the like These are used alone or in combination of two or more.

Examples of the (meth) acrylic acid ester monomers constituting the acrylic copolymer (a1) include alkyl (meth) acrylates, cycloalkyl (meth) acrylates, and benzyl (alkyl groups having 1 to 20 carbon atoms). Meta) acrylate or the like is used. Among these, more preferable are alkyl (meth) acrylates in which the alkyl group has 1 to 18 carbon atoms, and as a more specific example thereof, (meth) acrylic acid alkyl ester is (meth) Methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, (meth) acrylic Acid n-octyl, (meth) acrylate isooctyl, (meth) acrylate 2-ethylhexyl, (meth) acrylate n-nonyl, (meth) acrylate isononyl, decyl (meth) acrylate, undecyl (meth) acrylate , (Meth) acrylic acid dodecyl (lauryl (meth) acrylic acid), (meth) acrylic acid tride , Tetradecyl (meth) acrylate (mystyl (meth) acrylate), pentadecyl (meth) acrylate, hexadecyl (meth) acrylate (palmityl (meth) acrylate), heptadecyl (meth) acrylate (meth) Examples include octadecyl acrylate (stearyl (meth) acrylate), isooctadecyl (meth) acrylate (isostearyl (meth) acrylate) and the like.
The (meth) acrylic acid ester monomers can be used alone or in combination of two or more.

  The acrylic copolymer (a1) contains a constituent unit derived from the functional group-containing monomer preferably in a proportion of 3 to 100% by mass, more preferably 5 to 40% by mass, and (meth) acrylic acid ester The structural unit derived from the monomer or its derivative is preferably contained in a proportion of 0 to 97% by mass, more preferably 60 to 95% by mass.

  The acrylic copolymer (a1) can be obtained by copolymerizing the functional group-containing monomer as described above with a (meth) acrylic acid ester monomer or a derivative thereof in a conventional manner, but in addition to these monomers Also, other monomers such as dimethyl acrylamide, vinyl formate, vinyl acetate, styrene may be copolymerized.

  The energy ray-curable polymer (a) is produced by reacting the acrylic copolymer (a1) having the functional group-containing monomer unit with the unsaturated group-containing compound (a2) having a group bonding to the functional group. Is obtained.

  The said group which an unsaturated group containing compound (a2) has can be suitably selected according to the kind of functional group of the functional group containing monomer unit which an acryl-type copolymer (a1) has. For example, when the functional group is a hydroxyl group, an amino group or a substituted amino group, the group is preferably an isocyanate group or an epoxy group, and when the functional group is an epoxy group, the group is an amino group, a carboxyl group or an aziridinyl group Is preferred.

  The unsaturated group-containing compound (a2) preferably contains 1 to 5 and more preferably 1 to 2 energy ray-polymerizable carbon-carbon double bonds per molecule. Specific examples of such unsaturated group-containing compound (a2) include, for example, 2- (meth) acryloyloxyethyl isocyanate, meta-isopropenyl-α, α-dimethylbenzyl isocyanate, (meth) acryloyl isocyanate, allyl isocyanate 1,1- (bis (meth) acryloyloxymethyl) ethyl isocyanate; an acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth) acrylate; a diisocyanate compound or a polyisocyanate compound Acryloyl monoisocyanate compound obtained by the reaction of a polyol compound and hydroxyethyl (meth) acrylate; glycidyl (meth) acrylate; (meth) acre Lyric acid, 2- (1-aziridinyl) ethyl (meth) acrylate, 2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline and the like can be mentioned.

  The unsaturated group-containing compound (a2) is used usually in a proportion of 10 to 100 equivalents, preferably 20 to 95 equivalents, per 100 equivalents of the functional group-containing monomer of the acrylic copolymer (a1).

  In the reaction of the acrylic copolymer (a1) with the unsaturated group-containing compound (a2), the reaction temperature, the pressure during the reaction, the solvent, the reaction time, the catalyst, depending on the combination of the group and the functional group. In the case of using the catalyst, the type and the like can be appropriately selected. Thereby, the functional group present in the acrylic copolymer (a1) reacts with the group in the unsaturated group-containing compound (a2), and the unsaturated group is in the acrylic copolymer (a1). Is introduced into the side chain of the polymer to obtain an energy ray-curable polymer (A).

  The weight average molecular weight of the energy ray-curable polymer (a) is preferably 10,000 or more, more preferably 150,000 to 1,500,000, and still more preferably 200,000 to 1,000,000. The weight-average molecular weight (Mw) of the energy ray-curable polymer (A) in the present specification is a value in terms of standard polystyrene measured by gel permeation chromatography (GPC method).

Even when the energy ray-curable adhesive is based on a polymer having energy ray-curable properties, the energy ray-curable adhesive further contains an energy ray-curable monomer and / or oligomer (b) You may
Any of the energy ray-curable monomers and oligomers can be used alone or in combination of two or more.

  As the energy ray-curable monomer and / or oligomer (b), for example, an ester of polyhydric alcohol and (meth) acrylic acid can be used.

  Examples of the above energy ray-curable monomer and / or oligomer (b) include monofunctional acrylic esters such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate; trimethylolpropane tri (meth) acrylate, Pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene Multifunctional acrylic acid esters such as glycol di (meth) acrylate and dimethylol tricyclodecane di (meth) acrylate; polyester oligo (meth) acrylate, polyurethane oligo (meth) acrylate Rate, and the like.

  When the energy ray-curable monomer and / or oligomer (b) is blended, the content of the energy ray-curable monomer and / or oligomer (b) in the energy ray-curable adhesive is 5 to 80% by mass Is preferably 20 to 60% by mass.

  Here, when using an ultraviolet-ray as an energy ray for hardening an energy ray-curable resin composition, it is preferable to add a photoinitiator (c), and use of this photoinitiator (c) The polymerization curing time and the light irradiation amount can be reduced.

  Specific examples of the photopolymerization initiator (c) include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin benzoate, benzoin dimethyl ketal, 2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethyl thiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, β-chloroanthraquinone, (2,4, 6-trimethylbenzyl diphenyl) phosphine oxide, 2-benzothiazole-N, N-diethyldithiocarbamate, oligo {2-hydroxy-2-methy 1- [4- (1-propenyl) phenyl] propanone}, 2,2-dimethoxy-like. These may be used alone or in combination of two or more.

  The photopolymerization initiator (c) is 100 parts by mass of the energy ray-curable copolymer (a) (when the energy ray-curable monomer and / or oligomer (b) is blended, the energy ray-curable copolymer The amount is preferably in the range of 0.1 to 10 parts by mass, more preferably 0.5 to 6 parts by mass, based on 100 parts by mass of the total amount of (a) and the energy ray-curable monomer and / or oligomer (b). Used in the amount of

In the energy ray-curable pressure-sensitive adhesive, in addition to the above components, other components may be appropriately blended. As said other component, the polymer component or oligomer component (d) which does not have energy ray curability, a crosslinking agent (e) etc. are mentioned, for example.
The said other component can be used individually by 1 type or in combination of 2 or more types.

  Examples of the polymer component or oligomer component (d) not having energy ray curability include polyacrylic acid ester, polyester, polyurethane, polycarbonate, polyolefin and the like, and a polymer having a weight average molecular weight (Mw) of 3000 to 2.5 million. Or oligomers are preferred.

  As a crosslinking agent (e), the polyfunctional compound which has the reactivity with the functional group which energy-beam-curable copolymer (a) etc. have can be used. Examples of such polyfunctional compounds include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, ammonium salts And reactive phenol resins.

  By blending the polymer component or oligomer component (d) having no energy ray curability and the crosslinking agent (e) into the energy ray curable adhesive, the tackiness and releasability of the pressure-sensitive adhesive layer 42 before curing The strength after curing, the adhesion to other layers, the storage stability, etc. can be improved. The compounding quantity of these other components is not specifically limited, Preferably it determines suitably in 0-40 mass parts with respect to 100 mass parts of energy beam curing type copolymers (a).

  Next, the case where the energy ray-curable pressure-sensitive adhesive is mainly composed of a mixture of a polymer component having no energy ray-curable property and an energy ray-curable polyfunctional monomer and / or oligomer will be described below.

  As a polymer component which does not have energy ray curability, the component similar to the acrylic copolymer (a1) mentioned above can be used, for example. The content of the polymer component having no energy ray curing property in the energy ray curable resin composition is preferably 20 to 99.9% by mass, and more preferably 30 to 80% by mass.

  As the energy ray-curable polyfunctional monomer and / or oligomer, the same one as the component (b) described above is selected.

  In the energy ray-curable pressure-sensitive adhesive, the total compounding amount of the energy ray-curable polyfunctional monomer and the oligomer is preferably 10 to 150 parts by mass with respect to 100 parts by mass of the compounding amount of the polymer component, More preferably, it is part by mass.

  Even when the energy ray-curable pressure-sensitive adhesive is mainly composed of a mixture of a polymer component not having energy ray-curable properties and an energy ray-curable polyfunctional monomer and / or oligomer, similarly to the above, the photopolymerization initiation The agent (c) and the crosslinking agent (e) can be appropriately blended.

  The thickness of the pressure-sensitive adhesive layer 42 is not particularly limited as long as it can properly function in each process in which the protective film-forming sheet 3 is used. Specifically, the thickness of the pressure-sensitive adhesive layer 42 is preferably 1 to 50 μm, more preferably 2 to 30 μm, and still more preferably 3 to 20 μm.

  As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 5 for jigs, those having desired adhesion and removability are preferable, and, for example, acrylic pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives Polyester-based pressure-sensitive adhesives, polyvinyl ether-based pressure-sensitive adhesives and the like can be used. Among these, as the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 5 for jig, adhesion to a jig such as a ring frame is high, and the sheet 3 for forming a protective film is peeled off from the ring frame or the like in a dicing step or the like. An acrylic pressure-sensitive adhesive that can effectively suppress In the middle of the pressure-sensitive adhesive layer 5 for jigs, a base material as a core material may be interposed.

  The thickness of the jig pressure-sensitive adhesive layer 5 is preferably 5 to 200 μm, and more preferably 10 to 100 μm from the viewpoint of adhesion to a jig such as a ring frame.

2. Method of Producing Protective Film-Forming Sheet 3 Preferably, the protective film-forming sheet 3 separately prepares a first laminate containing the protective film-forming film 1 and a second laminate containing the adhesive sheet 4. It can manufacture by laminating | stacking the film 1 for protective film formation and the adhesive sheet 4 using a 1st laminated body and a 2nd laminated body after that, but it is not limited to this .

  In order to manufacture a 1st laminated body, the film 1 for protective film formation is formed in the peeling surface of a 1st peeling sheet. Specifically, a coating agent for a film for protective film formation, which contains a curable adhesive constituting the film for protective film formation 1 and optionally a solvent, is prepared, and a roll coater, a knife coater, a roll knife coater The protective film-forming film 1 is formed by applying and drying the release surface of the first release sheet with a coating machine such as an air knife coater, a die coater, a bar coater, a gravure coater, or a curtain coater. Next, the release surface of the second release sheet is overlapped on the exposed surface of the film 1 for forming a protective film and pressure-bonded, and a laminate 1 is formed by sandwiching the film 1 for forming a protective film between two release sheets. To obtain a laminate).

  In this first laminate, if desired, half cutting may be performed to make the protective film-forming film 1 (and the second release sheet) into a desired shape, for example, a circular shape or the like. In this case, excess portions of the film 1 for forming a protective film and the second release sheet generated by half cutting may be appropriately removed.

  On the other hand, in order to produce the second laminate, a coating agent for a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 42 and optionally a solvent is provided on the release surface of the third release sheet. It is applied and dried to form a pressure-sensitive adhesive layer 42. Thereafter, the base material 41 is pressure-bonded to the exposed surface of the pressure-sensitive adhesive layer 42, and a laminate (second laminate) including the pressure-sensitive adhesive sheet 4 including the substrate 41 and the pressure-sensitive adhesive layer 42 and the third release sheet is obtained. obtain.

  Here, when the pressure-sensitive adhesive layer 42 is formed of an energy ray-curable pressure-sensitive adhesive, the pressure-sensitive adhesive layer 42 may be cured by irradiating the pressure-sensitive adhesive layer 42 with energy rays at this stage. The pressure-sensitive adhesive layer 42 may be cured after being laminated with the film for film formation 1. Moreover, when making it harden | cure the adhesive layer 42 after laminating | stacking with the film 1 for protective film formation, you may harden the adhesive layer 42 before a dicing process, and may harden the adhesive layer 42 after a dicing process. .

Usually, ultraviolet rays, electron beams and the like are used as energy rays. Irradiation of energy rays varies depending on the kind of energy rays, for example, in the case of ultraviolet rays, it is preferable that the light amount is 50~1000mJ / cm ^2, and more preferably 100 to 500 mJ / cm ^2. In the case of an electron beam, it is preferably about 10 to 1000 krad.

  When the first laminate and the second laminate are obtained as described above, the second release sheet in the first laminate is peeled and the third release sheet in the second laminate is peeled. Then, the protective film-forming film 1 exposed in the first laminate and the pressure-sensitive adhesive layer 42 of the pressure-sensitive adhesive sheet 4 exposed in the second laminate are superposed and pressure-bonded. The pressure-sensitive adhesive sheet 4 may be half-cut, if desired, into a desired shape, for example, a circle having a larger diameter than the protective film-forming film 1 or the like. In this case, the extra part of the adhesive sheet 4 generated by half cutting may be removed as appropriate.

  Thus, the pressure-sensitive adhesive sheet 4 in which the pressure-sensitive adhesive layer 42 is laminated on the substrate 41, the protective film-forming film 1 laminated on the pressure-sensitive adhesive layer 42 side of the pressure-sensitive adhesive sheet 4, and a protective film The sheet | seat 3 for protective film formation which consists of the 1st peeling sheet laminated | stacked on the opposite side to the adhesive sheet 4 in the film 1 is obtained. Finally, after peeling off the first release sheet, the pressure-sensitive adhesive layer 5 for jig is formed on the periphery of the film 1 for protective film formation on the opposite side to the adhesive sheet 4. The jig pressure-sensitive adhesive layer 5 can also be formed by the same method as the pressure-sensitive adhesive layer 42 described above.

3. Method of Using Protective Film-Forming Sheet 3 The protective film-forming sheet 3 according to this embodiment is used to break a chip (workpiece) on which a protective film has been formed from a semiconductor wafer as a work as an example. A method of manufacturing by a manufacturing method including division processing by tension division by tension will be described below.

  As shown in FIG. 4, the protective film-forming film 1 of the protective film-forming sheet 3 is attached to the semiconductor wafer 6, and the jig pressure-sensitive adhesive layer 5 is attached to the ring frame 7. When sticking the film 1 for protective film formation on the semiconductor wafer 6, the film 1 for protective film formation may be heated depending on necessity, and adhesiveness may be exhibited.

Thereafter, the protective film-forming film 1 is cured to form a protective film.
Thus, a protective film is formed on the adhesive layer 42 side of the adhesive sheet 4 functioning as an extensible dicing sheet, and the semiconductor wafer 6 is formed on the opposite side of the protective film to the adhesive layer 42 side. A laminated structure (herein, the laminated structure is also referred to as “first laminated structure”) having a laminated structure is obtained. The first laminated structure shown in FIG. 4 further includes a jig pressure-sensitive adhesive layer 5 and a ring frame 7. When the protective film-forming film 1 is a thermosetting adhesive, the protective film may be formed by heating the protective film-forming film 1 at a predetermined temperature for an appropriate time. Curing of the protective film-forming film 1 may be performed after any of laser printing and division processing described below.

  When the first laminated structure including the semiconductor wafer 6 on which the protective film is formed as described above is obtained, the protective film is irradiated with a laser beam through the adhesive sheet 4 if desired, and the laser Print. Thus, a protective film was formed on the work using the protective film-forming sheet, and the surface on the protective film side of the work on which this protective film was formed was irradiated with laser light to form a printed protective film. Work can be manufactured. The laser printing may be performed after the division processing described below.

  Next, the first laminated structure is placed in a laser irradiation apparatus for division processing, the position of the surface of the semiconductor wafer 6 covered by the protective film 1 is detected, and then the semiconductor wafer 6 is processed using a processing laser. Form a reformed layer inside. Thereafter, by performing an expanding step of expanding the pressure-sensitive adhesive sheet 4 functioning as a dicing sheet, a force (tensile force in the main surface inward direction) is applied to the semiconductor wafer 6 with a protective film. As a result, the semiconductor wafer 6 with a protective film attached to the adhesive sheet 4 is divided to obtain a chip having a protective film (chip with a protective film). Thereafter, the protective film-attached chip is picked up from the adhesive sheet 4 using a pickup device.

  Here, the laser irradiation for printing may be performed not on the semiconductor wafer 6 on which the protective film is formed but on a chip on which the protective film is formed. That is, a protective film is formed on a work (semiconductor wafer 6) using a protective film forming sheet, and a workpiece (chip on which the protective film is formed by processing the work (semiconductor wafer 6) on which the protective film is formed ) May be obtained, and the surface on the protective film side of the workpiece (chip) on which the protective film is formed may be irradiated with laser light to produce a workpiece (chip) on which the printed protective film is formed .

  Whether the adherend of the protective film according to an embodiment of the present invention is a work (semiconductor wafer 6) or a workpiece (chip), the protective film has a pigment content of 2.6% by mass Since it is above, the light transmittance of wavelength 550 nm will be 15% or less, and the external appearance of the workpiece (semiconductor wafer 6) or workpiece (chip) which is a to-be-adhered body can be improved.

4. Another Embodiment of Protective Film-Forming Sheet FIG. 3 is a cross-sectional view of a protective film-forming sheet according to still another embodiment of the present invention. As shown in FIG. 3, the protective film-forming sheet 3 </ b> A according to the present embodiment includes the pressure-sensitive adhesive sheet 4 formed by laminating the pressure-sensitive adhesive layer 42 on one surface side of the substrate 41 and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet 4. And a protective film-forming film 1 laminated on the side of. The protective film-forming film 1 in the present embodiment is formed to be substantially the same as or slightly larger than the work in the surface direction and smaller in the surface direction than the adhesive sheet 4. The pressure-sensitive adhesive layer 42 in the portion where the protective film-forming film 1 is not laminated can be attached to a jig such as a ring frame.

  The material, thickness and the like of each member of the protective film forming sheet 3A according to the present embodiment are the same as the material, thickness and the like of each member of the protective film forming sheet 3 described above. However, when the pressure-sensitive adhesive layer 42 is made of an energy ray-curable pressure-sensitive adhesive, the portion of the pressure-sensitive adhesive layer 42 in contact with the protective film-forming film 1 cures the energy ray-curable pressure-sensitive adhesive, It is preferable not to cure the energy ray curable adhesive. As a result, the smoothness (gloss) of the protective film obtained by curing the protective film-forming film 1 can be increased, and the adhesive strength to a jig such as a ring frame can be maintained high.

  In addition, the adhesive for the jig similar to the adhesive layer 5 for jigs in the sheet 3 for protective film formation mentioned above in the peripheral part on the opposite side to the base material 41 in the adhesive layer 42 of the sheet 3A for protective film formation The agent layer may be separately provided.

  The embodiments described above are described to facilitate the understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents that fall within the technical scope of the present invention.

  For example, a release sheet may be laminated on the side of the protective film-forming film 1 of the protective film-forming sheets 3 and 3A opposite to the adhesive sheet 4.

  Hereinafter, the present invention will be described in more detail by way of specific examples. However, the present invention is not limited at all to the examples shown below.

<Manufacture of sheet for protective film formation>
Example 1
The following components were mixed at a compounding ratio (in terms of solid content) shown in Table 1 and diluted with methyl ethyl ketone so that the solid content concentration was 61% by mass, to prepare a coating agent for forming a protective film.
(A) Polymer component: acrylic polymer (weight-average molecular weight obtained by copolymerizing 10 parts by mass of n-butyl acrylate, 70 parts by mass of methyl acrylate, 5 parts by mass of glycidyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate : 400,000, glass transition temperature: -1 ° C)
(B-1) Bisphenol A type epoxy resin ("jER 828" manufactured by Mitsubishi Chemical Corporation, liquid at 23 ° C., 1 atm, molecular weight 370, softening point 93 ° C., epoxy equivalent of 183 to 194 g / eq)
(B-2) Bisphenol A type epoxy resin ("jER1055" manufactured by Mitsubishi Chemical Corporation, solid at 23 ° C., 1 atm, molecular weight 1600, epoxy equivalent 800 to 900 g / eq)
(B-3) Dicyclopentadiene type epoxy resin (“Epiclon HP-7200HH” manufactured by DIC, solid at 23 ° C., 1 atm, softening point 88 to 98 ° C., epoxy equivalent 255 to 260 g / eq)
(C-1) Thermally active latent epoxy resin curing agent (dicyandiamide, "ADEKA HARDNER EH-3636 AS" manufactured by ADEKA, active hydrogen amount 21 g / eq)
(C-2) Thermally active latent epoxy resin curing agent (dicyandiamide, "DICY7" manufactured by Mitsubishi Chemical Corporation)
(D) Hardening accelerator: 2-phenyl-4,5-dihydroxymethylimidazole ("Cuazole 2PHZ" manufactured by Shikoku Kasei Kogyo Co., Ltd.)
(E-1) Silica filler ("ADE050CMJA" manufactured by Admatechs, average particle size 0.05 μm)
(E-2) Silica filler ("SC2050MA" manufactured by Admatechs, average particle size 0.5 μm)
(E-3) Silica filler ("YC 100 CMLA" manufactured by Admatechs, average particle size 0.1 μm)
(E-4) Silica filler (Admatex Co., Ltd. "SC 1050" modified with vinyl group surface with silane coupling agent (Shin-Etsu Chemical Co., Ltd. "KBM 1003", average particle diameter 0.3 μm)
(F) Silane coupling agent ("KBM 403" manufactured by Shin-Etsu Chemical Co., Ltd.)
(G-1) Colorant (blue pigment): A pigment obtained by using a phthalocyanine-based blue pigment (Pigment Blue 15: 3) in an amount such that the mass ratio of the pigment component to the styrene-acrylic resin is 1/3.
(G-2) Colorant (yellow pigment): pigmented using an isoindolinone yellow pigment (Pigment Yellow 139) in an amount such that the mass ratio of the pigment component to the styrene-acrylic resin is 1/3.
(G-3) Colorant (red pigment): A pigment obtained by using a diketopyrrolopyrrole red pigment (Pigment Red 264) in an amount such that the mass ratio of the pigment component to the styrene-acrylic resin is 1/3.
(H) Colorant: carbon black ("MA600B" manufactured by Mitsubishi Chemical Corporation, average particle size 28 nm)

  Here, the weight average molecular weight (Mw) of the polymer component (A) is a weight average molecular weight in terms of standard polystyrene measured (GPC measurement) under the following conditions by gel permeation chromatography (GPC).

(GPC measurement conditions)
Column: TSKgel GMHXL (2), TSKgel 2000 HXL connected in this order Solvent: tetrahydrofuran Temperature: 40 ° C.
Flow rate: 1 ml / min Detector: Differential refractometer Standard sample: polystyrene

  A first release sheet (“Lintec's“ SP-PET 382150 ”, 38 μm thick) having a silicone release agent layer formed on one side of a polyethylene terephthalate (PET) film, and a silicone release on one side of a PET film A second release sheet ("SP-PET 381031" manufactured by Lintec Corporation, 38 μm thick) on which the agent layer is formed was prepared.

  After applying the coating agent for film formation for protective film formation mentioned above on the peeling surface of the 1st peeling sheet with a knife coater so that the thickness of the film for protective film formation finally obtained may be 23 micrometers. The resultant was dried at 120 ° C. for 2 minutes using an oven to form a protective film-forming film. Then, the release surface of the second release sheet is overlapped on the film for protective film formation, and both are pasted together, and the first release sheet (release sheet 21 in FIG. 1) and the film for protective film formation (protective film in FIG. 1) There was obtained a protective film-forming sheet comprising the forming film 1) (thickness: 25 μm) and the second release sheet.

[Examples 2 to 4, Reference Examples 1 to 5, Comparative Example 1]
A protective film-forming sheet was produced in the same manner as in Example 1 except that the types and amounts of the components constituting the protective film-forming film were changed as shown in Table 1.

<Evaluation of sheet for protective film formation>
(Light transmittance)
The second release sheet is peeled off from the protective film-forming sheet obtained in the above Examples and Reference Examples, and heated in an atmosphere at 130 ° C. for 2 hours in an oven to thermally cure the protective film-forming film. It was made to be a protective film. Thereafter, the first release sheet was released.

  The light transmittance of the protective film is measured using a spectrophotometer (“UV-VIS-NIR SPECTROPHOTOMETER UV-3600” manufactured by SHIMADZU), and the light transmittance (%) at wavelengths 550 nm, 1064 nm and 1250 nm is extracted. did. The measurement was performed using the attached large sample chamber MPC-3100 without using the built-in integrating sphere. The results are shown in Table 1.

(appearance)
The second release sheet is peeled off from the protective film-forming sheet obtained in the above Examples and Reference Examples, and the protective film-forming film is formed on the polished surface of a silicon wafer (# 200 polished, 200 mm in diameter, 280 μm in thickness). I attached it. A tape mounter ("Adwill RAD-3600" manufactured by Lintec Corporation) was used for sticking. After peeling the first release sheet from the protective film-forming film, the silicon wafer and the protective film-forming film are heated in an oven at 130 ° C. for 2 hours in the atmosphere to thermally cure the protective film-forming film. It was made to be a protective film. The obtained silicon wafer with a protective film was visually observed from the side of the protective film, and whether or not the polished surface of the silicon wafer was visually recognized through the protective film was confirmed according to the following criteria, and the appearance was evaluated. The results are shown in Table 1.
A: The polished surface is not visible at all.
B: The polished surface is slightly visible.
C: The polished surface is clearly visible.

(Measurement of 60 degree specular gloss)
The second release sheet is peeled off from the protective film-forming sheet obtained in the above Examples and Reference Examples, and the protective film-forming film is formed on the polished surface of a silicon wafer (# 200 polished, 200 mm in diameter, 280 μm in thickness). I attached it. A tape mounter ("Adwill RAD-3600" manufactured by Lintec Corporation) was used for sticking. After peeling the first release sheet from the protective film-forming film, the silicon wafer and the protective film-forming film are heated in an oven at 130 ° C. for 2 hours in the atmosphere to thermally cure the protective film-forming film. It was made to be a protective film. For the surface on the protective film side of the obtained protective film-coated silicon wafer, using a gloss meter “VG 2000” manufactured by Nippon Denshoku Kogyo Co., Ltd., according to JIS Z8741: 1997 (ISO 2813: 1994) Gs (60 °), unit:%) was measured. The results are shown in Table 1.

(Print visibility)
Laser printing was performed on the silicon wafer with a protective film obtained at the time of the measurement of the above-mentioned 60 degree specular gloss, using the green laser marker ("MD-S9910A" manufactured by KEYENCE CORPORATION) under the following conditions.
Wavelength: 532 nm
Output: 3.0 W
Frequency: 60kHz
Scanning speed: 500 mm / s
Printing character: ABCD
Character size: 300 μm (height) × 250 μm (width)
Character spacing: 50 μm

Next, the obtained print was observed with a digital microscope ("VHS-1000" manufactured by KEYENCE CORPORATION) at a magnification of 100 and evaluated in the following three steps (A to C). The results are shown in Table 1. The imaging data of the printed protective film is shown in FIG. 5 for Reference Example 1 and FIG. 6 for Reference Example 3.
A: Recognition of printing is easy, and printing looks clear.
B: Recognition of printing is easy.
C: Recognition of printing is difficult.

  As is clear from Table 1, the film for forming a protective film of Examples 1 to 4 in which the content of the pigment (organic pigment) is 2.6% by mass or more and the light transmittance at a wavelength of 550 nm is 13% or less The protective film formed from this made it possible to make the polished surface of the silicon wafer invisible at all or only slightly visible, thereby significantly improving the appearance of the wafer with a protective film.

  The film for forming a protective film and the sheet for forming a protective film according to the present invention can be used to manufacture a workpiece such as a semiconductor wafer having a protective film formed on the back surface thereof and a workpiece (chip or the like) thereof.

1 ... film for protective film formation 2 ... sheet for protective film formation 21 ... release sheet 3, 3 ... sheet for protective film formation 4 ... adhesive sheet 41 ... base material 42 · · ·・ Adhesive layer 5 ・ ・ ・ Adhesive layer for jig 6 ・ ・ ・ Semiconductor wafer 7 ・ ・ ・ Ring frame

In order to solve the above-mentioned subject, the present invention adopts the following composition.
[1]. A film retention Mamorumaku formed, the light transmittance of the wave length 550nm is 15% or less, light transmittance at a wavelength of 1250nm is 40% or more, the protective film formation film.
[2]. The film for protective film formation as described in [1] in which the said film for protective film formation contains a filler.
[3]. The 60 ° specular gloss Gs (60 °) defined in JIS Z8741: 1997 (ISO 2813: 1994) of the protective film formed from the protective film-forming film is 40% or more, [1] or [2] The film for protective film formation as described in these.
[4]. The film for protective film formation as described in any one of [1]-[3] whose light transmittance of wavelength 1064 nm is 50% or more.

Claims (14)

It is a film for protective film formation containing a pigment, and
The film for protective film formation whose content of the said pigment is 2.6 mass% or more, whose light transmittance of wavelength 550nm is 15% or less, and whose light transmittance of wavelength 1250 nm is 40% or more.   The film for protective film formation of Claim 1 in which the said film for protective film formation contains a filler.   The 60 ° specular gloss Gs (60 °) defined in JIS Z8741: 1997 (ISO 2813: 1994) of the protective film formed from the protective film-forming film is 40% or more. The film for protective film formation as described.   The film for protective film formation as described in any one of Claims 1-3 whose light transmittance of wavelength 1064 nm is 50% or more.   The film for protective film formation as described in any one of Claims 1-4 whose said pigment is an organic type pigment.   The film for protective film formation as described in any one of Claims 1-5 in which the said film for protective film formation contains an epoxy resin.   The film for protective film formation of Claim 6 in which the said epoxy resin contains an epoxy resin liquid at least at 23 degreeC and 1 atm.   The protective film formation as described in any one of Claims 1-7 laminated | stacked on the said adhesive layer side of the adhesive sheet in which an adhesive layer is laminated | stacked on one surface side of a base material, and the said adhesive sheet. Sheet for protective film formation provided with a film for   A workpiece or a workpiece formed by dividing the workpiece using the film for protective film formation according to any one of claims 1 to 7 or the sheet for protective film formation according to claim 8 A method of manufacturing a workpiece or a workpiece, which forms a film.   Irradiating laser light in the infrared region so that the division processing is focused on the focal point set in the work, forming a modified layer inside the work, and forming the modified layer on the work The manufacturing method of the workpiece | work or workpiece according to claim 9 which is processing which gives power and divides the workpiece in which said modification layer was formed, and obtains a plurality of piece-like objects as a workpiece.   The method for manufacturing a workpiece or a workpiece according to claim 9, wherein the workpiece is a semiconductor wafer and the workpiece is a semiconductor chip.   The inspection method which inspects via the said protective film using infrared rays about the workpiece | work or workpiece manufactured by the manufacturing method as described in any one of Claims 9-11.   A work determined to be non-defective based on the inspection method according to claim 12.   A processed product determined to be non-defective based on the inspection method according to claim 12.