JPH0677192A - Wafer working tape and its usage method - Google Patents

Abstract

PURPOSE:To obtain a wafer working tape wherein it does not contaminate a wafer and it is excellent in a water-resistant property by a method wherein a base-material film is coated with an acrlylic-resin. emulsion adhesive obtained by polymerizing a fluorine-containing monomer in a specific amount and a monomer mixture containing a reactive surface-active agent. CONSTITUTION:A reactive surface-active agent at 0.1 to 5.0 pts.wt. is mixed with a monomer mixture, at 100 pts.wt., in which a fluorine-containing monomer is 3.0 to 20.2wt.%, this mixture is polymerized and an acrylic-resin emulsion adhesive is obtained. A base-material film is coated with the acrylic-resin emulsion adhesive, and a wafer working tape is obtained. Trifluoro-ethylacrylate, heptadecafluorodecyl acrylate or the like can be enumerated as the fluorine- containing monomer. A compound in which an aryl group has been added to a benzene ring for polyoxyethylenealkyl phenyl ether can be enumerated as the reactive surface-active agent. When the acrylic-resin emulsion adhesive is used for the tape, a wafer is not contaminated when the wafer is worked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer processing tape. The wafer processing tape is used in a semiconductor integrated circuit (hereinafter referred to as IC) manufacturing process.

[0002]

2. Description of the Related Art In general, an IC is obtained by slicing a high-purity silicon single crystal or the like into a semiconductor wafer (hereinafter also simply referred to as a wafer), and then using a means such as impurity thermal diffusion or ultrafine processing on the surface thereof. It is manufactured by a method of incorporating an integrated circuit and dicing it into chips.

In each of these steps, a wafer processing tape is used on the surface of the wafer in order to prevent damage or damage to the surface pattern of the wafer.

Generally, water-based emulsion pressure-sensitive adhesives and solvent-based pressure-sensitive adhesives are used as pressure-sensitive adhesives.
From the viewpoint of hygiene and cost, the water-based emulsion adhesive is preferable.

In addition, when the film for wafer processing is used for wafer processing and then cleaned to remove deposits on the wafer surface, when a film using a solvent-based adhesive is used, it is contaminated by water cleaning. Can not be completely removed, and it takes time and labor to use an organic solvent, which is problematic in terms of safety and hygiene.
On the other hand, in the film using the water-based emulsion adhesive,
Contamination can be sufficiently removed by washing with water.

However, the water-based emulsion pressure-sensitive adhesive has a drawback that it is inferior in water resistance as compared with the solvent-based pressure-sensitive adhesive. As a wafer processing tape that overcomes this drawback, we have developed a wafer processing tape that uses an acrylic resin emulsion adhesive prepared by adding fluorine-containing monomer to the adhesive material monomer and polymerizing.

However, since the fluorine-containing monomer has water repellency and oil repellency, it has poor compatibility with other monomers, and a large amount of a surfactant is required to mix these monomers. . The pressure-sensitive adhesive obtained by polymerization is
On the contrary, the water resistance deteriorates, and the surfactant bleeds on the surface and contaminates the surface of the wafer when it is peeled after being attached to the wafer.

[0008]

SUMMARY OF THE INVENTION In view of the above points, an object of the present invention is to provide a wafer processing tape which does not contaminate the wafer and is excellent in water resistance.

[0009]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that when a fluorine-containing monomer is added to a monomer of a pressure-sensitive adhesive raw material and polymerized, a reactive surfactant is used. When used, the bond with the emulsion particles is a physical bond, separation of the fluorine-containing monomer and other monomers does not occur, and the addition amount can be polymerized in an amount smaller than that of the non-reactive surfactant, and obtained by polymerization. The present invention has been completed based on the finding that a wafer processing tape obtained by applying the acrylic resin emulsion pressure-sensitive adhesive formulation liquid thus obtained to a substrate film does not contaminate the wafer and is excellent in water resistance.

That is, in the present invention, 0.1 to 5.0 parts by weight of a reactive surfactant is added to 100 parts by weight of a monomer mixture containing a fluorine-containing monomer in an amount of 3.0 to 20.0% by weight and polymerized. The tape for wafer processing is characterized in that after being made into an acrylic resin emulsion pressure-sensitive adhesive, the acrylic resin emulsion pressure-sensitive adhesive is applied to a substrate film.

The present invention is also a wafer backside grinding method characterized by using the same wafer processing tape.

The monomer mixture is a (meth) acrylic acid ester monomer such as methyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate or ethyl acrylate, and acrylic acid or methacrylic acid, which is a carboxylic acid-containing vinyl compound. It is a mixture of monomers such as crotonic acid, maleic acid, fumaric acid and itaconic acid, and a fluorine-containing monomer.

The fluorine-containing monomer is a vinyl compound containing fluorine, and examples thereof include trifluoroethyl acrylate, trifluoroethyl methacrylate, heptadecafluorodecyl acrylate, and heptadecafluorodecyl methacrylate.

The fluorine-containing monomer in the monomer mixture is 3.0-20.0% by weight. More preferably, it is 5.0 to 10.0% by weight. If it is less than 3.0% by weight, the water resistance will not be improved, and if it exceeds 20.0% by weight, the compatibility with other monomers will be poor and the copolymerization will not be successful.

The reactive surfactant during polymerization used in the present invention can be appropriately selected as long as it has a vinyl group in the molecule, preferably a nonionic surfactant or an anionic ammonium salt. It is a surfactant.

For example, the nonionic surfactant is a compound obtained by adding an allyl group to the benzene ring of polyoxyethylene alkylphenyl ether, and the anionic surfactant is polyoxyethylene alkylphenyl ether sulfate. Examples thereof include a compound obtained by adding an allyl group to a benzene ring of a compound salt, a compound obtained by adding a sulfate to a compound obtained by adding a higher alcohol and an allyl group to maleic acid, and the like.

However, with anionic surfactants such as soda salt and potassium salt, sodium ions and potassium ions remaining in the pressure-sensitive adhesive may lead to corrosion of the wafer.

The amount of the reactive surfactant added is 0.1 to 5.0 parts by weight, and more preferably 0.2 to 3.0 parts by weight, based on 100 parts by weight of the monomer mixture. . If the amount is less than 0.1 parts by weight, the stability during polymerization is poor, many aggregates are generated, and the yield is poor. If it exceeds 3.0 parts by weight, the resulting pressure-sensitive adhesive film absorbs water, resulting in poor water resistance.

The acrylic resin emulsion pressure-sensitive adhesive is a pressure-sensitive adhesive obtained by emulsion polymerization in water by adding a reactive surfactant, deionized water, and a polymerization initiator to a monomer mixture, and it is necessary to select the monomer composition. It can be appropriately performed according to the strength. The acrylic resin emulsion pressure-sensitive adhesive thus polymerized is usually 30 to 60 wt% in addition to water.
% Solid content (acrylic resin), it may be further diluted with water for viscosity adjustment at the time of application.

If necessary, a crosslinking agent such as an epoxy type can be added to the acrylic resin emulsion pressure-sensitive adhesive.

As the base film used in the present invention, a film made of synthetic resin, natural or synthetic rubber can be appropriately selected.

As an example of the material of the base film, ethylene-vinyl acetate copolymer, polybutadiene,
Soft vinyl chloride resin, polyolefin, polyester,
Thermoplastic elastomers such as polyamide, and synthetic rubbers such as diene-based, nitrile-based, silicon-based, and acrylic-based rubbers.

As a method for applying the acrylic resin emulsion pressure-sensitive adhesive compounding liquid to the base film, it is applied by a known coating method such as reverse roll coater, gravure coater, bar coater, die coater, comma coater, etc. It is possible by drying with hot air at 150 ° C. The coating thickness after drying is usually 1 μm to 100
It is about μm.

Further, it is preferable to attach a synthetic resin film called a separator to the pressure-sensitive adhesive layer side in order to protect the pressure-sensitive adhesive layer, if necessary.

The method of grinding the back surface of the wafer is not particularly limited, and known methods such as physical grinding using a grinder or chemical grinding such as chemical etching may be appropriately used.

[0026]

The present invention will be described in more detail with reference to the following examples. Example 1 In a flask equipped with a thermometer, a reflux condenser, a dropping funnel, a nitrogen inlet and a stirrer, 150.0 parts by weight of deionized water,
As a reactive surfactant, 3.0 parts by weight of a compound obtained by adding an allyl group to a benzene ring of polyoxyethylene nonylphenyl ether (20 mol of ethylene oxide) was added, and the temperature was raised to 70 ° C. under stirring in a nitrogen atmosphere. Then, 0.5 part by weight of ammonium persulfate (polymerization initiator) is added and dissolved. Then, methyl methacrylate 2
2.5 parts by weight, 2-ethylhexyl acrylate 63.
A monomer mixture consisting of 5 parts by weight, 2.0 parts by weight of glycidyl methacrylate, 2.0 parts by weight of methacrylic acid and 10.0 parts by weight of trifluoroethyl acrylate was continuously added dropwise over 4 hours, and stirring was continued for 3 hours after the addition was completed. Polymerization was continued to obtain an acrylic resin emulsion adhesive having a solid content of about 40% by weight.

An EV prepared by film-forming this compounded liquid by the T-die method
A roll-coater was used to coat the corona-treated EVA surface of a 110 μm-thick film consisting of two layers of A and PP.
It was dried at 0 ° C. to obtain a wafer processing tape having an acrylic resin emulsion pressure-sensitive adhesive layer with a coating thickness of 30 μm.

The wafer processing tape obtained in this way is specified by JIS
Attached to a SUS plate having a maximum height of 30 μm at a reference length of 0.8 mm specified in B 0601,
It was immersed in water and evaluated for water resistance. What is this reference length?
It is the reference measurement length of the sample when measuring the roughness of the surface of the measured object.

The evaluation method was as follows. The SUS plate having the wafer processing tape attached thereto was immersed in water for 10 minutes, and the water penetration area was evaluated. The ratio of the penetration area to the total area of the SUS board was expressed as a percentage. Indicated. The size of the SUS plate is 5 cm in width, 20 cm in length, and 100 in area.

Further, water droplets were dropped on the surface of the adhesive of the wafer processing tape, and the contact angle was measured. The greater the water repellency, the greater the contact angle.

Further, the wafer processing tape is further
After sticking to an inch semiconductor wafer using an automatic tape sticking machine ("ATM-1000B" manufactured by Takatori Co., Ltd.) and left at room temperature for 1 day, an automatic tape peeling machine ("ATRM-2000B" manufactured by Takatori Co., Ltd.) was used. The wafer processing tape was peeled off using the obtained 4-inch semiconductor wafer, and a surface inspection device HLD-3 manufactured by Hitachi Electronics Engineering Co., Ltd.
The contamination degree of the wafer was measured according to the number of foreign matters having a size of 0.2 μm or more due to 00B. As shown in Table 1, the results showed that the water resistance was good and the wafer was not contaminated.

Example 2 22.5 parts by weight of methyl methacrylate, acrylic acid-2-
A monomer mixture consisting of 70.5 parts by weight of ethylhexyl, 2.0 parts by weight of glycidyl methacrylate, 2.0 parts by weight of methacrylic acid, and 3.0 parts by weight of heptadecafluorodecyl acrylate was added, and polyoxy was used as a reactive surfactant. Example 1 was repeated except that 0.1 part by weight of a compound obtained by adding an allyl group to a benzene ring of an ammonium salt of ethylene nonylphenyl ether sulfate (10 mol of ethylene oxide) was used. Using this blended solution, a tape for wafer processing was obtained in the same manner as in Example 1. The tape for wafer processing thus obtained was evaluated in the same manner as in Example 1.
The results were good as shown in [Table 1].

Example 3 22.5 parts by weight of methyl methacrylate, acrylic acid-2-
100 parts by weight of a monomer mixture consisting of 53.5 parts by weight of ethylhexyl, 2.0 parts by weight of glycidyl methacrylate, 2.0 parts by weight of methacrylic acid and 20.0 parts by weight of heptadecafluorodecylmethacrylate were added, and a reactive surfactant was added. As an ammonium salt of polyoxyethylene nonylphenyl ether sulfate (ethylene oxide 1
The same procedure as in Example 1 was carried out except that 5.0 parts by weight of a compound obtained by adding an allyl group to a benzene ring (0 mol) was used. Using this blended solution, a tape for wafer processing was obtained in the same manner as in Example 1. The wafer processing tape thus obtained was used in Example 1.
It evaluated similarly to. The results were good as shown in [Table 1].

Comparative Example 1 22.5 parts by weight of methyl methacrylate, acrylic acid-2-
Using 100 parts by weight of a monomer mixture consisting of 73.5 parts by weight of ethylhexyl, 2.0 parts by weight of glycidyl methacrylate and 2.0 parts by weight of methacrylic acid, an ammonium salt of polyoxyethylene nonylphenyl ether sulfate as a reactive surfactant. Compound 3.0 in which an allyl group is added to the benzene ring of (ethylene oxide 10 mol)
Same as Example 1 except that parts by weight were used. Using this blended solution, a tape for wafer processing was obtained in the same manner as in Example 1. The tape for wafer processing thus obtained was evaluated in the same manner as in Example 1. As a result, as shown in [Table 1], the water resistance was poor.

Comparative Example 2 22.5 parts by weight of methyl methacrylate, acrylic acid-2-
A monomer mixture consisting of 68.5 parts by weight of ethylhexyl, 2.0 parts by weight of glycidyl methacrylate, 2.0 parts by weight of methacrylic acid and 5.0 parts by weight of trifluorodecyl acrylate was added, and polyoxyethylene nonylphenyl was used as a surfactant. Polymerization was carried out in the same manner as in Example 1 except that 5.0 parts by weight of ether (ethylene oxide 10 mol) was used, but the compatibility of the monomers was poor and the polymerization could not be carried out. Comparative Example 3 22.5 parts by weight of methyl methacrylate, acrylic acid-2-
A monomer mixture consisting of 68.5 parts by weight of ethylhexyl, 2.0 parts by weight of glycidyl methacrylate, 2.0 parts by weight of methacrylic acid and 5.0 parts by weight of heptadecafluorodecyl acrylate was added, and polyoxyethylene nonyl was used as a surfactant. Example 1 was repeated except that 10.0 parts by weight of ammonium salt of phenyl ether sulfate (10 mol of ethylene oxide) was used. Using this blended solution, a tape for wafer processing was obtained in the same manner as in Example 1.
The tape for wafer processing thus obtained was evaluated in the same manner as in Example 1. As a result, as shown in [Table 1], the water resistance was poor.

Comparative Example 4 22.5 parts by weight of methyl methacrylate, acrylic acid-2-
A monomer mixture consisting of 43.5 parts by weight of ethylhexyl, 2.0 parts by weight of glycidyl methacrylate, 2.0 parts by weight of methacrylic acid, and 30.0 parts by weight of heptadecafluorodecyl methacrylate was added, and polyoxy was used as a reactive surfactant. Polymerization was conducted in the same manner as in Example 1 except that 5.0 parts by weight of a compound obtained by adding an allyl group to a benzene ring of ethylene nonylphenyl ether (20 mol of ethylene oxide) was used. There wasn't.

Comparative Example 5 Methyl methacrylate 22.5 parts by weight, acrylic acid-2-
A monomer mixture consisting of 70.5 parts by weight of ethylhexyl, 2.0 parts by weight of glycidyl methacrylate, 2.0 parts by weight of methacrylic acid and 3.0 parts by weight of heptadecafluorodecyl methacrylate was added, and polyoxy was used as a reactive surfactant. Polymerization was conducted in the same manner as in Example 1 except that 0.05 part by weight of a compound obtained by adding an allyl group to a benzene ring of an ammonium salt of ethylene nonylphenyl ether sulfate (10 mol of ethylene oxide) was used. Was bad and could not be polymerized.

Comparative Example 6 22.5 parts by weight of methyl methacrylate, acrylic acid-2-
A monomer mixture consisting of 63.5 parts by weight of ethylhexyl, 2.0 parts by weight of glycidyl methacrylate, 2.0 parts by weight of methacrylic acid, and 10.0 parts by weight of heptadecafluorodecyl acrylate was added, and polyoxy was used as a reactive surfactant. Example 1 was repeated except that 10.0 parts by weight of a compound obtained by adding an allyl group to a benzene ring of ethylene nonylphenyl ether (20 mol of ethylene oxide) was used. Using this blended solution, a tape for wafer processing was obtained in the same manner as in Example 1. The tape for wafer processing thus obtained was evaluated in the same manner as in Example 1. As a result, as shown in [Table 1], the water resistance was poor.

Comparative Example 7 Methyl methacrylate 22.5 parts by weight, acrylic acid-2-
A monomer mixture consisting of 72.5 parts by weight of ethylhexyl, 2.0 parts by weight of glycidyl methacrylate, 2.0 parts by weight of methacrylic acid and 1.0 part by weight of heptadecafluorodecyl acrylate was added, and polyoxy was used as a reactive surfactant. Example 1 was repeated except that 0.5 part by weight of a compound obtained by adding an allyl group to a benzene ring of an ammonium salt of ethylene nonylphenyl ether sulfate (10 mol of ethylene oxide) was used. Using this blended solution, a tape for wafer processing was obtained in the same manner as in Example 1. The tape for wafer processing thus obtained was evaluated in the same manner as in Example 1.
As a result, as shown in [Table 1], the water resistance was poor.

[0040]

[Table 1]

[0041]

By using an acrylic resin emulsion pressure-sensitive adhesive obtained by polymerizing a monomer mixture containing a fluorine-containing monomer with a reactive surfactant, the wafer processing tape has excellent water resistance and does not contaminate the wafer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoko Takeuchi 2-1, Tangodori, Minami-ku, Aichi Prefecture Nagoya City Mitsui Toatsu Chemicals, Inc.

Claims (2)

[Claims] 1. The fluorine-containing monomer is 3.0 to 20.0.
After adding 0.1 to 5.0 parts by weight of a reactive surfactant to 100 parts by weight of a monomer mixture (weight%), polymerization is carried out to obtain an acrylic resin emulsion pressure-sensitive adhesive, and the acrylic resin emulsion pressure-sensitive adhesive is used as a base. A wafer processing tape characterized by being applied to a material film. 2. A wafer backside grinding method, wherein the wafer processing tape according to claim 1 is used.