JP5748170B2 - Radiation curable inkjet ink, recorded matter, and inkjet recording method - Google Patents

Description

  The present invention relates to a radiation curable ink jet ink, a recorded matter, and an ink jet recording method.

  Conventionally, various methods have been used as a recording method for forming an image on a recording medium based on an image data signal. Among these, the ink jet system is an inexpensive apparatus, and ink is ejected only to a required image portion to form an image directly on a recording medium. Therefore, the ink can be used efficiently, and the running cost is low.

  In recent years, in order to form good images such as water resistance, solvent resistance, and abrasion resistance on the surface of a recording medium, a radiation curable inkjet ink that is cured when irradiated with radiation is used in an inkjet recording method. Has been.

  On the other hand, in recent years, electronic parts (IC packages) formed by packaging semiconductor chips (integrated circuit (IC) chips) have been used in various devices, and such electronic parts include characters, symbols, logo marks, and the like. It is usual to carry out markings for printing etc. For this reason, there is a demand for a printing technique for applying markings suitable for electronic components.

  For example, Patent Document 1 discloses a marking method in which an ink attached to an electronic component such as an IC chip is irradiated with ultraviolet rays to fix the ink on the electronic component. Patent Document 2 discloses a marking method in which a lot number or the like is printed by an inkjet method on a discarded substrate portion at a peripheral portion of a substrate on which a large number of bare chips are taken.

  Further, for example, Patent Document 3 discloses an inkjet in printed wiring board manufacturing in which the integrated light quantity and illuminance of irradiated ultraviolet rays are in a specific range so that ink containing titanium dioxide is cured with a maximum ink film thickness of 10 to 30 μm. A recording method is disclosed. Patent Document 4 discloses a step of providing a marking by jetting an ultraviolet curable ink containing a colorant, a photopolymerization initiator, and an epoxy reagent onto a printed circuit board from an inkjet printer, and the marking is performed for at least 2 seconds. An inkjet printing method is disclosed that includes a step of subsequent exposure to ultraviolet light.

  Further, for example, Patent Document 5 discloses a molded IC package in which an IC package is coated and marked thereon. Patent Document 6 discloses a method for marking only a defective IC chip in a wafer having a plurality of IC chips.

JP 11-274335 A JP 2000-332376 A JP 2006-21479 A JP-T-2007-527459 Utility Model Registration No. 2539839 Specification JP 2003-273172 A

  However, all of the techniques disclosed in Patent Documents 1 to 6 are inferior to at least one of abrasion resistance, adhesion, and alcohol resistance. Therefore, the conventional marking method has a problem that it is difficult to apply it to a precise electronic component.

  Accordingly, it is an object of the present invention to provide a radiation curable inkjet ink excellent in abrasion resistance, adhesion, and alcohol resistance, a recorded matter using the same, and an inkjet recording method.

  The present inventors have intensively studied to solve the above problems. When marking an electronic component using a conventional marking method, the cured product of the ink recorded on the electronic component is inferior to at least one of rubbing resistance, adhesion, and alcohol resistance, and cannot be practically used. .

That is, the present invention is as follows.
[1]
A discharge step of discharging radiation curable inkjet ink onto a package substrate or a semiconductor substrate;
A curing step of irradiating the ejected ink with radiation to cure the ink;
A heating step of heating a cured product obtained by curing at 150 to 200 ° C .;
An ink jet recording method comprising:
3 to 25% by mass of the radiation curable inkjet ink based on the total mass of the ink
N-vinylcaprolactam and 5 to 20% by weight of a polyfunctional acrylate based on the total weight of the ink,
The package base material encloses a semiconductor chip, and the material of the package base material is at least one of epoxy resin, phenol resin, silicon resin, polyimide, and polymethyl methacrylate.
Inkjet recording method.
[2]
The inkjet recording method according to [1], wherein the multifunctional acrylate is a multifunctional acrylate having a pentaerythritol skeleton.
[3]
A discharge step of discharging radiation curable inkjet ink onto a package substrate or a semiconductor substrate;
A curing step of irradiating the ejected ink with radiation to cure the ink;
A heating step of heating a cured product obtained by curing at 150 to 200 ° C. for 10 to 75 minutes;
An ink jet recording method comprising:
5 to 20% by mass of the radiation curable inkjet ink based on the total mass of the ink
N-vinylcaprolactam,
The package base material encloses a semiconductor chip, and the material of the package base material is at least one of epoxy resin, phenol resin, silicon resin, polyimide, and polymethyl methacrylate.
Inkjet recording method.
[4]
A discharge step of discharging radiation curable inkjet ink onto a package substrate or a semiconductor substrate;
A curing step of irradiating the ejected ink with radiation to cure the ink;
A heating step of heating a cured product obtained by curing at 150 to 200 ° C .;
An ink jet recording method comprising:
5 to 20% by mass of the radiation curable inkjet ink based on the total mass of the ink
N-vinylcaprolactam,
The irradiated radiation has an emission peak wavelength in the range of 350 to 405 nm, and integrated illumination.
The amount of radiation is 100 mJ / cm ² or more,
The package base material encloses a semiconductor chip, and the material of the package base material is at least one of epoxy resin, phenol resin, silicon resin, polyimide, and polymethyl methacrylate.
Inkjet recording method.
[5]
Radiation curable inkjet ink used in the inkjet recording method described in any one of [1] to [4] above.
[6]
Package base material or semiconductor base material as recording medium, and package base material or semiconductor
And a cured product of radiation-curable inkjet ink recorded on a substrate, and obtained by the inkjet recording method according to any one of [1] to [4] above.

  In this way, a radiation curable inkjet ink (hereinafter, also simply referred to as “ink”) containing a predetermined amount of N-vinylcaprolactam, which is cured and heat-treated under predetermined conditions, is an electronic component package. It can be suitably recorded (marked) on a base material or a semiconductor base material, and has been found to be excellent in both the abrasion resistance and alcohol resistance of the cured product and the adhesion of the cured product to the substrate. Completed the invention.

That is, the present invention is as follows.
[1]
A discharge step of discharging radiation curable inkjet ink onto a package substrate or a semiconductor substrate;
A curing step of irradiating the ejected ink with radiation to cure the ink;
A heating step of heating a cured product obtained by curing at 150 to 200 ° C .;
An ink jet recording method comprising:
5 to 20% by mass of the radiation curable inkjet ink based on the total mass of the ink
N-vinylcaprolactam and 5 to 20% by weight of a polyfunctional acrylate based on the total weight of the ink,
The package base material encloses a semiconductor chip, and the material of the package base material is at least one of epoxy resin, phenol resin, silicon resin, polyimide, and polymethyl methacrylate.
Inkjet recording method.
[2]
The inkjet recording method according to [1], wherein the multifunctional acrylate is a multifunctional acrylate having a pentaerythritol skeleton.
[3]
A discharge step of discharging radiation curable inkjet ink onto a package substrate or a semiconductor substrate;
A curing step of irradiating the ejected ink with radiation to cure the ink;
A heating step of heating a cured product obtained by curing at 150 to 200 ° C. for 10 to 75 minutes;
An ink jet recording method comprising:
5 to 20% by mass of the radiation curable inkjet ink based on the total mass of the ink
N-vinylcaprolactam,
The package base material encloses a semiconductor chip, and the material of the package base material is at least one of epoxy resin, phenol resin, silicon resin, polyimide, and polymethyl methacrylate.
Inkjet recording method.
[4]
A discharge step of discharging radiation curable inkjet ink onto a package substrate or a semiconductor substrate;
A curing step of irradiating the ejected ink with radiation to cure the ink;
A heating step of heating a cured product obtained by curing at 150 to 200 ° C .;
An ink jet recording method comprising:
5 to 20% by mass of the radiation curable inkjet ink based on the total mass of the ink
N-vinylcaprolactam,
The irradiated radiation has an emission peak wavelength in the range of 350 to 405 nm, and integrated illumination.
The amount of radiation is 100 mJ / cm ² or more,
The package base material encloses a semiconductor chip, and the material of the package base material is at least one of epoxy resin, phenol resin, silicon resin, polyimide, and polymethyl methacrylate.
Inkjet recording method.
[5]
Radiation curable inkjet ink used in the inkjet recording method described in any one of [1] to [4] above.
[6]
Package base material or semiconductor base material as recording medium, and package base material or semiconductor
And a cured product of radiation-curable inkjet ink recorded on a substrate, and obtained by the inkjet recording method according to any one of [1] to [4] above.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. In addition, this invention is not restrict | limited to the following embodiment, A various deformation | transformation can be implemented within the range of the summary.

  In the present specification, the “package base material” means a protective base material that encloses a semiconductor chip or the like. The “semiconductor base material” means a semiconductor chip or the like that includes a wafer that directly becomes a base material. Hereinafter, the package substrate or the semiconductor substrate is also referred to as “package substrate or the like”. The “recorded material” refers to a material in which a cured product is formed by recording ink on a package substrate or a semiconductor substrate. In addition, the hardened | cured material in this specification means the hardened | cured substance containing the cured film and coating film of an ink.

  In this specification, “curing” means that when an ink containing a polymerizable compound is irradiated with radiation, the polymerizable compound is polymerized and the ink is solidified. “Curable” refers to the property of curing in response to light. “Adhesiveness” refers to the property that the coating film is difficult to peel off from the substrate. In particular, in the embodiment, the property when a right-angled lattice pattern is cut into the cured product and penetrates to the substrate such as a package substrate. Say. “Abrasion resistance” refers to the property that when the cured product is scratched, the cured product is difficult to peel off from the package substrate or the like. “Alcohol resistance” refers to the property that when a recorded product is immersed in an isopropyl alcohol solution and then the cured product is scratched, the cured product is difficult to peel off from the package substrate or the like. “Discharge stability” refers to the property of ejecting stable ink droplets from the nozzles without clogging the nozzles.

  In this specification, “(meth) acrylate” means at least one of acrylate and its corresponding methacrylate, and “(meth) acryl” means at least one of acryl and its corresponding methacryl.

[Radiation curable ink jet ink]
The radiation curable inkjet ink according to an embodiment of the present invention contains 5 to 20% by mass of N-vinylcaprolactam with respect to the total mass (100% by mass) of the ink. Moreover, after the said ink is hardened | cured by radiation irradiation, it heat-processes at 150-200 degreeC, and becomes a hardened | cured material. Further, the ink has a feature that it is suitable for use in recording on a package substrate or a semiconductor substrate as a recording medium.

  Hereinafter, additives (components) included in the radiation-curable ink jet ink of the present embodiment or which may be included as desired will be described.

[Polymerizable compound]
The polymerizable compound contained in the radiation curable inkjet ink of this embodiment can be polymerized at the time of light irradiation by the action of a photopolymerization initiator described later, and the printed ink can be cured.

(N-vinylcaprolactam)
The polymerizable compound in this embodiment contains N-vinylcaprolactam. When the ink contains N-vinylcaprolactam as a polymerizable compound, the curability, adhesion, abrasion resistance, and alcohol resistance can be improved.

  The content of N-vinylcaprolactam is 5 to 20% by mass and preferably 9 to 15% by mass with respect to the total mass (100% by mass) of the ink. When the content of N-vinylcaprolactam is within the above range, the adhesiveness, abrasion resistance, and alcohol resistance are excellent.

(Compound having both vinyl and (meth) acryl groups in the molecule)
The polymerizable compound in the present embodiment may contain a compound represented by the following general formula (I) (hereinafter referred to as “monomer A”).
_{^{CH 2 = CR 1 -COOR 2 -O}} -CH = CH-R 3 ··· (I)
Wherein R ¹ is a hydrogen atom or a methyl group, R ² is a divalent organic residue having 2 to 20 carbon atoms, and R ³ is a hydrogen atom or a monovalent organic residue having 1 to 11 carbon atoms. Group.)

The monomer A is a compound having both a vinyl group and a (meth) acryl group in the molecule, and can be rephrased as vinyl ether group-containing (meth) acrylic acid esters.
When the ink contains the monomer A, the curability of the ink can be improved.

In the general formula (I), the divalent organic residue represented by R ² includes a linear, branched or cyclic alkylene group having 2 to 20 carbon atoms, an ether bond and an ester in the structure. An alkylene group having 2 to 20 carbon atoms having an oxygen atom due to at least one of the bonds, and an optionally substituted divalent aromatic group having 6 to 11 carbon atoms are preferable. Among these, C2-C6 alkylene groups such as ethylene group, n-propylene group, isopropylene group, and butylene group, oxyethylene group, oxy n-propylene group, oxyisopropylene group, and oxybutylene group An alkylene group having 2 to 9 carbon atoms having an oxygen atom due to an ether bond in the structure is preferably used.

In said general formula (I), as a C1-C11 monovalent organic residue represented by R < ³ >, a C1-C10 linear, branched or cyclic alkyl group, carbon An optionally substituted aromatic group of formula 6 to 11 is preferred. Among these, C6-C2 aromatic groups, such as a C1-C2 alkyl group which is a methyl group or an ethyl group, a phenyl group, and a benzyl group, are used suitably.

  When the above organic residue is an optionally substituted group, the substituent is divided into a group containing a carbon atom and a group not containing a carbon atom. First, when the substituent is a group containing a carbon atom, the carbon atom is counted in the carbon number of the organic residue. Examples of the group containing a carbon atom include, but are not limited to, a carboxyl group and an alkoxy group. Next, examples of the group not containing a carbon atom include, but are not limited to, a hydroxyl group and a halo group.

  Specific examples of the monomer A represented by the above general formula (I) include, but are not limited to, 2-vinyloxyethyl (meth) acrylate, 3-vinyloxypropyl (meth) acrylate, (meth) acrylic acid 1-methyl-2-vinyloxyethyl, 2-vinyloxypropyl (meth) acrylate, 4-vinyloxybutyl (meth) acrylate, 1-methyl-3-vinyloxypropyl (meth) acrylate, (meth) acrylic acid 1- Vinyloxymethylpropyl, 2-methyl-3-vinyloxypropyl (meth) acrylate, 1,1-dimethyl-2-vinyloxyethyl (meth) acrylate, 3-vinyloxybutyl (meth) acrylate, (meth) acrylic acid 1 -Methyl-2-vinyloxypropyl, 2-vinyloxybutyl (meth) acrylate, 4-bi (meth) acrylate Roxycyclohexyl, 6-vinyloxyhexyl (meth) acrylate, 4-vinyloxymethylcyclohexylmethyl (meth) acrylate, 3-vinyloxymethylcyclohexylmethyl (meth) acrylate, 2-vinyloxymethyl (meth) acrylate Cyclohexylmethyl, (meth) acrylic acid p-vinyloxymethylphenylmethyl, (meth) acrylic acid m-vinyloxymethylphenylmethyl, (meth) acrylic acid o-vinyloxymethylphenylmethyl, (meth) acrylic acid 2- ( Vinyloxyethoxy) ethyl, 2- (vinyloxyisopropoxy) ethyl (meth) acrylate, 2- (vinyloxyethoxy) propyl (meth) acrylate, 2- (vinyloxyethoxy) isopropyl (meth) acrylate, ( 2-methacrylic acid (vinyloxy) Propoxy) propyl, 2- (vinyloxyisopropoxy) isopropyl (meth) acrylate, 2- (vinyloxyethoxyethoxy) ethyl (meth) acrylate, 2- (vinyloxyethoxyisopropoxy) ethyl (meth) acrylate, 2- (vinyloxyisopropoxyethoxy) ethyl (meth) acrylate, 2- (vinyloxyisopropoxyisopropoxy) ethyl (meth) acrylate, 2- (vinyloxyethoxyethoxy) propyl (meth) acrylate, (meth ) 2- (vinyloxyethoxyisopropoxy) propyl acrylate, 2- (vinyloxyisopropoxyethoxy) propyl (meth) acrylate, 2- (vinyloxyisopropoxyisopropoxy) propyl (meth) acrylate, (meth) Acrylic acid 2- (vinyloxyethoxy ester) Toxi) isopropyl, (meth) acrylic acid 2- (vinyloxyethoxyisopropoxy) isopropyl, (meth) acrylic acid 2- (vinyloxyisopropoxyethoxy) isopropyl, (meth) acrylic acid 2- (vinyloxyisopropoxyisopropoxy) ) Isopropyl, 2- (vinyloxyethoxyethoxyethoxy) ethyl (meth) acrylate, 2- (vinyloxyethoxyethoxyethoxyethoxy) ethyl (meth) acrylate, 2- (isopropenoxyethoxy) ethyl (meth) acrylate , 2- (Isopropenoxyethoxyethoxy) ethyl (meth) acrylate, 2- (Isopropenoxyethoxyethoxyethoxy) ethyl (meth) acrylate, 2- (Isopropenoxyethoxyethoxyethoxyethoxy) acrylate (meth) acrylate ethyl (Meth) Polyethylene glycol monovinyl ether acrylate, and (meth) acrylic acid polypropylene glycol monovinyl ether.

  Among those described above, 2-vinyloxyethyl (meth) acrylate, 3-vinyloxypropyl (meth) acrylate, 1-methyl-2-vinyloxyethyl (meth) acrylate, 2-vinyloxypropyl (meth) acrylate, ( 4-vinyloxybutyl (meth) acrylate, 4-vinyloxycyclohexyl (meth) acrylate, 5-vinyloxypentyl (meth) acrylate, 6-vinyloxyhexyl (meth) acrylate, 4-vinyloxy (meth) acrylate Methylcyclohexylmethyl, p-vinyloxymethylphenylmethyl (meth) acrylate, 2- (vinyloxyethoxy) ethyl (meth) acrylate, 2- (vinyloxyethoxyethoxy) ethyl (meth) acrylate, (meth) acrylic The acid 2- (vinyloxyethoxyethoxyethoxy) ethyl is preferred Arbitrariness.

  Of these, 2- (vinyloxyethoxy) ethyl (meth) acrylate is preferred because of its low viscosity, high flash point, and excellent curability, and it also has low odor and suppresses irritation to the skin. In addition, 2- (vinyloxyethoxy) ethyl acrylate is more preferable because it is excellent in reactivity and adhesion.

  Examples of 2- (vinyloxyethoxy) ethyl (meth) acrylate include 2- (2-vinyloxyethoxy) ethyl (meth) acrylate and 2- (1-vinyloxyethoxy) ethyl (meth) acrylate. Examples of 2- (vinyloxyethoxy) ethyl acrylate include 2- (2-vinyloxyethoxy) ethyl acrylate and 2- (1-vinyloxyethoxy) ethyl acrylate.

  Monomer A may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content of the monomer A is preferably 20 to 50% by mass with respect to the total mass (100% by mass) of the ink. When the content of the monomer A is within the above range, ink adhesion, abrasion resistance, and alcohol resistance can be further improved.

The production method of the monomer A represented by the general formula (I) is not limited to the following, but is a method of esterifying (meth) acrylic acid and a hydroxyl group-containing vinyl ether (production method B), (meth) acrylic acid. Method of esterifying halide and hydroxyl group-containing vinyl ether (Production method C), Method of esterifying (meth) acrylic anhydride and hydroxyl group-containing vinyl ether (Production method D), (Meth) acrylic acid ester and hydroxyl group Method of Transesterifying Containing Vinyl Ethers (Production Method E), Method of Esterifying (Meth) acrylic Acid and Halogen-Containing Vinyl Ethers (Production Method F), Alkali (Meth) Acrylic Acid (Earth) Metal Salt and Halogen Containing Method of esterifying vinyl ethers (Production G), hydroxyl group-containing (meth) acrylic acid esters and carboxylic acid vinyl ester How to vinyl exchange and Le (Procedure H), hydroxyl group-containing (meth) How to ether exchange and acrylic acid esters and alkyl vinyl ethers (formula I).
Among these, since the desired effect can be further exhibited in this embodiment, the production method E is preferable.

(Polymerizable compounds other than the above)
As the polymerizable compound other than the above (hereinafter, referred to as “other polymerizable compound”), conventionally known various monomers and oligomers such as monofunctional, bifunctional, and trifunctional or more polyfunctional can be used. . Examples of the monomer include unsaturated carboxylic acids such as (meth) acrylic acid, itaconic acid, crotonic acid, isocrotonic acid and maleic acid, salts or esters thereof, urethane, amide and anhydride thereof, acrylonitrile, styrene, various types Unsaturated polyesters, unsaturated polyethers, unsaturated polyamides, and unsaturated urethanes. Examples of the oligomer include oligomers formed from the above monomers such as linear acrylic oligomers, epoxy (meth) acrylate, oxetane (meth) acrylate, aliphatic urethane (meth) acrylate, and aromatic urethane (meth). Acrylate and polyester (meth) acrylate are mentioned.

  Moreover, N-vinyl compounds other than N-vinylcaprolactam may be included as another monofunctional monomer or polyfunctional monomer. Examples of such N-vinyl compounds include N-vinylformamide, N-vinylcarbazole, N-vinylacetamide, N-vinylpyrrolidone, and acryloylmorpholine, and derivatives thereof.

  Among other polymerizable compounds, an ester of (meth) acrylic acid, that is, (meth) acrylate is preferable, polyfunctional (meth) acrylate having 2 or more functions is more preferable, and polyfunctional acrylate is more preferable. In particular, the ink of the present embodiment includes a polyfunctional acrylate as a polymerizable compound in addition to the predetermined amount of N-vinylcaprolactam, thereby improving adhesion, rubbing resistance, and alcohol resistance. can do.

  Among the above (meth) acrylates, monofunctional (meth) acrylates include, for example, isoamyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, iso Myristyl (meth) acrylate, isostearyl (meth) acrylate, 2-ethylhexyl-diglycol (meth) acrylate, 2-hydroxybutyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxydiethylene glycol ( (Meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate , Tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, lactone-modifiable Examples include flexible (meth) acrylate, t-butylcyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and dicyclopentenyloxyethyl (meth) acrylate.

  Among the (meth) acrylates, examples of the polyfunctional (meth) acrylate include triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and tripropylene glycol di ( (Meth) acrylate, polypropylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl Glycol di (meth) acrylate, dimethylol-tricyclodecane di (meth) acrylate, di (meth) acrylate of bisphenol A, neopentyl glycol di (meth) acrylate of hydroxypivalate, and poly Bifunctional (meth) acrylates such as tetramethylene glycol di (meth) acrylate, as well as trimethylolpropane tri (meth) acrylate, glycerin propoxytri (meth) acrylate, cowprolactone modified trimethylolpropane tri (meth) acrylate, ditri (Meth) having a pentaerythritol skeleton such as methylolpropane tetra (meth) acrylate, sorbitol penta (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and pentaerythritol ethoxytetra (meth) acrylate Acrylate, dipentaerythritol hexa (meth) acrylate, caprolactam-modified dipentaerythritol hexa (meth) acrylate , (Pentaerythritol penta (meth) acrylate), (meth) acrylate having a dipentaerythritol skeleton such as caprolactone-modified dipentaerythritol hexa (meth) acrylate, propionic acid-modified tripentaerythritol penta (meth) acrylate, tripentaerythritol hexa (Meth) acrylate, tripentaerythritol hepta (meth) acrylate, (meth) acrylate having a tripentaerythritol skeleton such as tripentaerythritol octa (meth) acrylate, tetrapentaerythritol penta (meth) acrylate, tetrapentaerythritol hexa ( (Meth) acrylate, tetrapentaerythritol hepta (meth) acrylate, tetrapentaerythritol octa ( (Meth) acrylate, tetrapentaerythritol nona (meth) acrylate, tetrapentaerythritol nona (meth) acrylate, tetrapentaerythritol deca (meth) acrylate and other (meth) acrylates having pentapentaerythritol skeleton, pentapentaerythritol undeca ( (Meth) acrylate and (meth) acrylate having a pentapentaerythritol skeleton such as pentapentaerythritol dodeca (meth) acrylate, and at least one of these ethylene oxide (EO) adduct and propylene oxide (PO) adduct, etc. Trifunctional or higher functional (meth) acrylates may be mentioned.

  Among these, it is preferable that another polymeric compound contains polyfunctional (meth) acrylate as above-mentioned. Among the polyfunctional (meth) acrylates, the polyfunctional (meth) acrylate having the pentaerythritol skeleton is preferable, and the polyfunctional acrylate having the pentaerythritol skeleton is more preferable. As the polyfunctional (meth) acrylate having a pentaerythritol skeleton, at least one of pentaerythritol tri (meth) acrylate and pentaerythritol tetra (meth) acrylate is preferable, and at least one of pentaerythritol triacrylate and pentaerythritol tetraacrylate Is more preferable. In the above case, in addition to being more excellent in adhesion, rubbing resistance and alcohol resistance, the viscosity of the ink is lowered and the crosslink density in the ink is increased.

  Among monofunctional (meth) acrylates, in order to reduce viscosity and odor, at least one of phenoxyethyl (meth) acrylate and isobornyl (meth) acrylate is preferred, phenoxyethyl (meth) acrylate is more preferred, and phenoxy More preferred is ethyl acrylate.

  The said other polymeric compound may be used individually by 1 type, and may use 2 or more types together.

  The other polymerizable compound may be contained in an amount of 5 to 50% by mass with respect to the total mass (100% by mass) of the ink. Among them, the polyfunctional acrylate is more excellent in adhesion, abrasion resistance, and alcohol resistance, and therefore it is preferably contained in an amount of 5 to 20% by mass, more preferably 8 to 15% by mass with respect to the total mass (100% by mass) of the ink. More preferably.

(Polymerization inhibitor)
The ink of this embodiment may contain a polymerization inhibitor. Examples of polymerization inhibitors include, but are not limited to, p-methoxyphenol, cresol, t-butylcatechol, di-t-butylparacresol, hydroquinone monomethyl ether, α-naphthol, 3,5-di-t-butyl. -4-hydroxytoluene, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-butylphenol), and 4,4'-thiobis (3- Phenol compounds such as methyl-6-t-butylphenol), p-benzoquinone, anthraquinone, naphthoquinone, phenanthraquinone, p-xyloquinone, p-toluquinone, 2,6-dichloroquinone, 2,5-diphenyl-p-benzoquinone 2,5-diacetoxy-p-benzoquinone, 2,5-dicaproxy-p- Quinone compounds such as nzoquinone, 2,5-diacyloxy-p-benzoquinone, hydroquinone, 2,5-dibutylhydroquinone, mono-t-butylhydroquinone, monomethylhydroquinone, and 2,5-di-t-amylhydroquinone, phenyl- β-naphthylamine, p-benzylaminophenol, di-β-naphthylparaphenylenediamine, amine compounds such as dibenzylhydroxylamine, phenylhydroxylamine, and diethylhydroxylamine, nitro compounds such as dinitrobenzene, trinitrotoluene, and picric acid , Oxime compounds such as quinonedioxime and cyclohexanone oxime, and sulfur compounds such as phenothiazine.

(Photopolymerization initiator)
The ink of this embodiment preferably contains a photopolymerization initiator. By using a photopolymerizable compound as the above-described polymerizable compound, it is possible to omit the addition of a photopolymerization initiator. However, it is preferable to use a photopolymerization initiator because the start of polymerization can be easily adjusted.

  The photopolymerization initiator is used to form an image by curing ink present on the surface of a recording medium by photopolymerization by irradiation with radiation. Here, examples of the radiation include γ rays, β rays, electron beams, ultraviolet rays (UV), visible rays, and infrared rays. Among these, ultraviolet rays are preferable because they are excellent in safety and can reduce the cost of the light source. The photopolymerization initiator is not limited as long as it generates active species such as radicals and cations by the energy of light and initiates the polymerization of the polymerizable compound. A polymerization initiator can be used, and among these, it is preferable to use a radical photopolymerization initiator.

  Examples of the photo radical polymerization initiator include aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds (thioxanthone compounds, thiophenyl group-containing compounds, etc.), hexaarylbiimidazoles, and the like. Examples include compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon halogen bond, and alkylamine compounds.

  Among these, since the curability of the ink can be particularly improved, at least one of an acylphosphine oxide compound and a thioxanthone compound is preferable, and an acylphosphine oxide compound is more preferable.

  Specific examples of the photo radical polymerization initiator include acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine. , Carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, 4,4′-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyldimethyl ketal, 1- (4-isopropylphenyl) ) -2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthio Xanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, bis (2,4,6-trimethylbenzoyl) -phenyl Phosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2,4-diethylthioxanthone, and bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide Can be mentioned.

  Examples of commercially available photo radical polymerization initiators include IRGACURE 651 (2,2-dimethoxy-1,2-diphenylethane-1-one), IRGACURE 184 (1-hydroxy-cyclohexyl-phenyl-ketone), DAROCUR 1173. (2-hydroxy-2-methyl-1-phenyl-propan-1-one), IRGACURE 2959 (1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane- 1-one), IRGACURE 127 (2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl] -2-methyl-propan-1-one}, IRGACURE 907 (2-Methyl-1- (4-methylthiophenyl) -2-morphol Linopropan-1-one), IRGACURE 369 (2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1), IRGACURE 379 (2- (dimethylamino) -2-[(4- Methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone), DAROCUR TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide), IRGACURE 819 (bis (2, 4,6-trimethylbenzoyl) -phenylphosphine oxide), IRGACURE 784 (bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole-1-) Yl) -phenyl) titanium), IRGACURE OXE 01 (1.2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)]), IRGACURE OXE 02 (ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime)), IRGACURE 754 (oxyphenylacetic acid, 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester and oxyphenylacetic acid, 2- (Mixture of (2-hydroxyethoxy) ethyl ester) (above, manufactured by BASF), KAYACURE DETX-S (2,4-diethylthioxanthone) (manufactured by Nippon Kayaku Co., Ltd.), Speedcure TPO , Speedcure DETX (above, manufactured by Lambson), Lucirin TPO, LR8883, LR 970 (manufactured by BASF), and Ubecryl P36 (manufactured by UCB), and the like.

  The said photoinitiator may be used individually by 1 type, and may be used in combination of 2 or more type.

  The photopolymerization initiator exhibits a sufficient radiation curing rate, and avoids undissolved photopolymerization initiator and coloring derived from the photopolymerization initiator, so that the total amount (100% by mass) of the ink is 5%. It is preferable to contain ~ 20 mass%.

[Color material]
The ink of this embodiment may include a color material. As the color material, at least one of a pigment and a dye can be used.

(Pigment)
In the present embodiment, by using a pigment as the color material, the light resistance of the ink can be improved. As the pigment, both inorganic pigments and organic pigments can be used.

  As the inorganic pigment, carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black and channel black, iron oxide, and titanium oxide can be used.

  Organic pigments include insoluble azo pigments, condensed azo pigments, azo lakes and chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxane pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc. Polycyclic pigments, dye chelates (eg basic dye chelates, acid dye chelates, etc.), dye rakes (basic dye rakes, acid dye rakes), nitro pigments, nitroso pigments, aniline black, daylight A fluorescent pigment is mentioned.

  More specifically, as carbon black used as black ink, No. 2300, no. 900, MCF88, No. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, no. 2200B and the like (manufactured by Mitsubishi Chemical Corporation), Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, Raven 700, etc. (and above, manufactured by Columbia Columbia), Regal 400R, Rega1 330R, Rega1 660R, Mogul L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, etc. (CABOT JAPAN K. F. manufactured by CABOT JAPAN B.C. , Color Black FW2, Color Black FW2V, Color Black FW 18, Color Black FW200, Color B1ack S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140U, Special Black 6, Sep, Special Black S6, Color Black S160, Color Black S160, Color Black S170, Color Black S170, Color Black S170, Color Black S170, Color Black S170 Degussa)).

  Examples of pigments used in white ink include C.I. I. Pigment white 6, 18, and 21.

  Examples of pigments used in yellow ink include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114, 117, 120, 124, 128, 129, 133, 138, 139, 147, 151, 153, 154, 167, 172, 180.

  Examples of pigments used in magenta ink include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 88, 112, 114, 122, 123, 144, 146, 149, 150, 166, 168 170, 171, 175, 176, 177, 178, 179, 184, 185, 187, 202, 209, 219, 224, 245, or C.I. I. Pigment violet 19, 23, 32, 33, 36, 38, 43, 50.

  Examples of pigments used for cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15, 15: 1, 15: 2, 15: 3, 15:34, 15: 4, 16, 18, 22, 25, 60, 65, 66, C.I. I. Bat Blue 4, 60.

  Examples of pigments other than magenta, cyan, and yellow include C.I. I. Pigment green 7,10, C.I. I. Pigment brown 3, 5, 25, 26, C.I. I. Pigment orange 1, 2, 5, 7, 13, 14, 15, 16, 24, 34, 36, 38, 40, 43, 63.

  The said pigment may be used individually by 1 type, and may use 2 or more types together.

  When the above pigment is used, the average particle size is preferably 300 nm or less, and more preferably 50 to 250 nm. When the average particle diameter is in the above range, the ink can be more excellent in reliability such as ejection stability and dispersion stability, and an image with excellent image quality can be formed. Here, the average particle diameter in the present specification is measured by a dynamic light scattering method.

(dye)
In the present embodiment, a dye can be used as the color material. The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used. Examples of the dye include C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. I. Acid Red 52, 80, 82, 249, 254, 289, C.I. I. Acid Blue 9, 45, 249, C.I. I. Acid Black 1, 2, 24, 94, C.I. I. Food Black 1, 2, C.I. I. Direct Yellow 1,12,24,33,50,55,58,86,132,142,144,173, C.I. I. Direct Red 1,4,9,80,81,225,227, C.I. I. Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202, C.I. I. Directed Black 19, 38, 51, 71, 154, 168, 171, 195, C.I. I. Reactive Red 14, 32, 55, 79, 249, C.I. I. Reactive black 3, 4, and 35 are mentioned.

  The said dye may be used individually by 1 type, and may use 2 or more types together.

  The content of the color material is preferably 1 to 25% by mass and more preferably 1 to 20% by mass with respect to the total mass (100% by mass) of the ink because excellent concealability and color reproducibility are obtained.

[Dispersant]
When the ink of this embodiment contains a pigment, it may further contain a dispersant in order to improve pigment dispersibility. Although it does not specifically limit as a dispersing agent, For example, the dispersing agent currently used for preparing pigment dispersion liquids, such as a polymer dispersing agent, is mentioned. Specific examples include polyoxyalkylene polyalkylene polyamines, vinyl polymers and copolymers, acrylic polymers and copolymers, polyesters, polyamides, polyimides, polyurethanes, amino polymers, silicon-containing polymers, sulfur-containing polymers, fluorine-containing polymers, and epoxies. The thing which has 1 or more types of resin as a main component is mentioned. Commercially available polymer dispersants include Ajinomoto Fine Techno Co., Ajisper series, Solsperz series available from Avecia Co. (Solsperse 36000, etc.), BYK Dispervic series, Enomoto Kasei Co., Ltd. Disparon series made by the company.

[Slip agent]
The ink according to the present embodiment may further include a slip agent (surfactant) because excellent abrasion resistance is obtained. The slip agent is not particularly limited. For example, polyester-modified silicone or polyether-modified silicone can be used as a silicone-based surfactant, and polyether-modified polydimethylsiloxane or polyester-modified polydimethylsiloxane is particularly used. preferable. Specific examples include BYK-347, BYK-348, BYK-UV3500, 3510, 3530, and 3570 (above, manufactured by BYK).

[Other additives]
The ink of this embodiment may contain additives (components) other than the additives listed above. Such components are not particularly limited, and may include, for example, conventionally known polymerization accelerators, penetration enhancers, wetting agents (humectants), and other additives. Examples of the other additives include conventionally known fixing agents, antifungal agents, preservatives, antioxidants, radiation absorbers, chelating agents, pH adjusting agents, and thickeners.

[Recording medium]
The radiation curable inkjet ink of the present embodiment can be recorded by being ejected onto a recording medium using an inkjet recording method described later. A package substrate or a semiconductor substrate is used as the recording medium. This is because the ink used for marking on a package substrate or the like is required to have excellent adhesion, abrasion resistance, and alcohol resistance.

  As defined above, the package base material means a protective base material that encloses semiconductor chips and the like, and the semiconductor base material also includes a wafer that is a semiconductor chip or the like and also directly serves as a base material. . Then, an electronic component (IC package) is manufactured by enclosing the semiconductor chip or the like. An electronic device is formed by integrating one or more of these electronic components.

  As the standard of the package substrate, for example, PGA (Pin Grid Array), DIP (Dual Inline Package), SIP (Single Inline Package), ZIP (Zigzag Inline Package), DO (Diode Outline) package, and TO (Transistoristor). ) Insertion type packages such as packages, as well as P-BGA (Plastic Ball grid array), T-BGA (Tape Ball grid array), F-BGA (Fine Pitch Ball grid array), SOJ (Small Outline J-OP) (Thin Small Outline Package), SON Small Outline Non-lead), QFP (Quad Flat Package), CFP (Ceramic Flat Package), SOT (Small Outline Transistor), PLCC (Plastic led chip carrier, L), GA (L) And surface mount packages such as TCP (Tape carrier package), LLP (Leadless Leadframe Package), and DFN (Dual Flatpack Non-lead).

  As a commercially available package base material, for example, a general purpose logic IC package (SOP14-P-300-1.27A) manufactured by Toshiba Semi-Conductor Co., Ltd., Renesas Electronics Corporation Surface mount package (UPA2350B1G) manufactured by Sharp Corporation, surface mount package package (P-LFBGA048-0606) manufactured by Sharp Corporation, and serial EEPROM (BR24L01A) manufactured by ROHM Co., Ltd. It is done.

  As a material of the package base material, a non-absorbable material can be used in order to prevent ink from penetrating into the electronic component main body. Specific examples of the non-absorbing material include, but are not limited to, metals such as gold, silver, copper, aluminum, iron-nickel alloys, stainless steel, and brass, and semiconductors (for example, silicon), carbides, nitrides. And inorganic substances such as borides (eg silicon nitride) and organic substances such as silicon, epoxy resins, phenolic resins, polyimides, and polymethyl methacrylate (PMMA).

  Especially, since it is excellent in the adhesiveness to the base material of hardened | cured material, as a package base material, a silicone or an epoxy resin is more preferable. Thus, by using a package substrate made of silicon or epoxy resin as a sealing material for electronic components, the ink of the above-described embodiment can be suitably recorded (marked) on the outer surface of the package substrate.

  On the other hand, commercially available semiconductor substrates (wafers) include, for example, a 300 mm silicon wafer manufactured by Shin-Etsu Chemical Co., Ltd., an SOI wafer manufactured by SUMCO, and Covalent Materials. Corporation).

  Examples of the material for the semiconductor substrate include silicon, germanium, and selenium. Among these, silicon is preferable because it has excellent adhesion to ink and is extremely stable as a semiconductor material.

  Examples of the electronic device include a flash memory card such as a USB memory, a memory card, an SD memory card, a memory stick, a smart media, an xD picture card, and a compact flash (registered trademark).

  Here, a marking method for a package substrate or the like will be described.

  First, when marking on a wafer as a semiconductor substrate, it may be marked on a wafer before dicing, or after forming a circuit on the wafer and marking on a semiconductor chip diced into chips. May be. In the latter case, a silicon wafer on which an IC (integrated circuit) is formed generally forms a silicon oxide film on the wafer surface during the circuit formation process. As a method for forming the silicon oxide film, for example, a high frequency sputtering method which is one of the methods excellent in controlling the thickness can be given. Using this method, silicon dioxide as a target material can be sputtered onto a silicon wafer.

  Next, when marking on the package substrate, the semiconductor chip may be marked on the package substrate after encapsulation, or on the package substrate before encapsulation of the semiconductor chip.

The electronic component is manufactured by bonding a pad of a semiconductor chip and a lead frame and encapsulating the entire chip together with a sealing agent in a package substrate. Examples of the sealant include, but are not limited to, an epoxy resin, a phenol resin, and a silicon resin. Marking can be performed on the electronic component thus manufactured (outer surface).
In addition, when the ink is applied to a non-absorbable recording medium, it may be necessary to provide a drying step after being cured by irradiation with radiation.

  Thus, according to the present embodiment, it is possible to provide a radiation curable ink jet ink excellent in adhesion, abrasion resistance, and alcohol resistance. Furthermore, according to the present embodiment, it has excellent adhesion to a pre-processed package base material, etc., and is excellent in abrasion resistance and resistance to flux cleaning (for example, by isopropyl alcohol (IPA)). In addition, a radiation curable inkjet ink can be provided.

  In addition, the ink of the present embodiment exhibits the excellent effects as described above in combination with being subjected to heat treatment under a predetermined temperature condition after curing. This heat treatment will be described in detail in the section of the inkjet recording method described later.

[Recordings]
One embodiment of the present invention relates to a recorded matter. In the recorded matter, the radiation curable inkjet ink of the above-described embodiment is recorded on a package base material or the like as a recording medium, and the recorded on the package base material or the package base material or the like. A cured product of ink. The recorded matter is characterized by excellent adhesion between the package base material and the ink (cured product) adhered and cured thereon, and the cured ink is excellent in abrasion resistance and alcohol resistance.

  Thus, according to the present embodiment, a recorded matter using a radiation curable ink jet ink excellent in adhesion, rubbing resistance, and alcohol resistance can be provided.

[Inkjet recording method]
One embodiment of the present invention relates to an inkjet recording method. The ink jet recording method includes a discharge step of discharging and adhering the radiation curable ink jet ink of the above embodiment onto a package substrate or the like (recording medium), and irradiating the ink discharged by the discharge step with actinic radiation. Thus, a curing process for curing the ink and a heating process for heating a cured product obtained by curing under a predetermined condition are included. In this way, a cured product is formed from the ink that has been subjected to radiation irradiation and heat treatment on the package substrate or the like. Hereafter, each said process is demonstrated in detail.

[Discharge process]
In the ejection step, a conventionally known ink jet recording apparatus can be used. In discharging the ink, the viscosity of the ink is preferably 30 mPa · s or less, and more preferably 5 to 20 mPa · s. If the ink viscosity is as described above with the ink temperature set to room temperature or the ink not heated, the ink may be discharged at room temperature or without heating the ink. On the other hand, the ink may be discharged with a preferable viscosity by heating the ink to a predetermined temperature. In this way, good discharge stability is realized.

[Curing process]
Next, in the curing step, the ink ejected on the package substrate or the like is cured by irradiation with radiation (light).
Specifically, the polymerization reaction of the polymerizable compound starts upon irradiation with radiation. In addition, the photopolymerization initiator contained in the ink is decomposed by irradiation with radiation to generate initiating species such as radicals, acids, and bases, and the polymerization reaction of the polymerizable compound is promoted by the function of the initiating species. . At this time, if the sensitizing dye is present together with the photopolymerization initiator in the ink, the sensitizing dye in the system absorbs actinic radiation to be in an excited state and contacts the photopolymerization initiator to decompose the photopolymerization initiator. It can be accelerated and a more sensitive curing reaction can be achieved.

  As a radiation source, a mercury lamp, a gas / solid laser or the like is mainly used, and as a light source used for curing a radiation curable ink jet ink, a mercury lamp and a metal halide lamp are widely known. On the other hand, there is a strong demand for mercury-free from the viewpoint of environmental protection, and replacement with a GaN-based semiconductor ultraviolet light-emitting device is very useful industrially and environmentally. Furthermore, ultraviolet light-emitting diodes (UV-LEDs) and ultraviolet laser diodes (UV-LDs) are small, have a long life, have high efficiency, and are low in cost, and are expected as light sources for radiation-curable ink jets. Among these, UV-LED is preferable.

The radiation irradiated in this step preferably cures the ink sufficiently and exhibits the desired effect by performing the next heating step, and therefore preferably satisfies the following conditions. First, the emission peak wavelength of radiation is preferably in the range of 350 to 405 nm, and more preferably in the range of 365 to 395 nm. Further, the integrated irradiation amount (irradiation energy) is preferably 100 mJ / cm ² or more, preferably 600 mJ / cm ² or less, and more preferably 200~500mJ / cm ^2.
In addition, it is preferable that the irradiation intensity | strength of a radiation is 500 mW / cm < ² > or less, and it is more preferable that it is 200-400 mW / cm < ² >.

  In the above case, curing at low energy and high speed is possible due to the composition of the ink of the above embodiment. The integrated irradiation dose is calculated by multiplying the irradiation time by the irradiation intensity. Irradiation time can be shortened by the composition of the ink of the said embodiment, and printing speed increases. On the other hand, the irradiation intensity can also be reduced by the composition of the ink of the above-described embodiment, so that downsizing and cost reduction of the apparatus are realized. In this case, UV-LED is preferably used for radiation irradiation. Such an ink is obtained by including a photopolymerization initiator that decomposes upon irradiation with radiation in the above wavelength range and a polymerizable compound that initiates polymerization upon irradiation with radiation in the above wavelength range. The emission peak wavelength may be one or plural within the above wavelength range. Even if there is a plurality, the total irradiation energy of the radiation having the emission peak wavelength is set as the integrated irradiation amount.

[Heating process]
Next, in the heating step, the cured product obtained by curing the ink through the curing step is subjected to heat treatment. Through this heat treatment, when a polymerizable compound that is not polymerized or insufficiently polymerized remains in the cured ink, the polymerization degree is further increased by polymerization of the polymerizable compound, and curing is performed. It is presumed that at least one of the polymer in the ink formed by heating forms a network structure and becomes hard. As a result, the cured product is excellent in both abrasion resistance and alcohol resistance, and adhesion of the cured product to the substrate. However, the factors are not limited to the above.

  The heating temperature in the heat treatment is 150 to 200 ° C, and preferably 160 to 190 ° C. When the heating temperature is in the above range, all of the abrasion resistance, adhesion, and alcohol resistance can be excellent. In addition to this, the heating time in the heat treatment is preferably 5 to 75 minutes, more preferably 10 to 75 minutes, and still more preferably 20 to 70 minutes. When the heating time is in the above range, in addition to the same characteristics as described above, the influence of heat on the package substrate or the like can be minimized.

  As described above, according to the present embodiment, it is possible to provide an ink jet recording method using a radiation curable ink jet ink that is excellent in all of abrasion resistance, adhesion, and alcohol resistance.

  Hereinafter, the embodiments of the present invention will be described more specifically by way of examples. However, the embodiments are not limited to these examples.

[Raw materials]
The raw materials used in the following examples and comparative examples are as follows.
[Polymerizable compound]
N-vinylcaprolactam (manufactured by BASF, abbreviated as “NVC” in Table 1)
VEEA (2- (2-vinyloxyethoxy) ethyl acrylate, trade name manufactured by Nippon Shokubai Co., Ltd.)
・ PET3A (Pentaerythritol triacrylate, OSAKA ORGANIC CHEMICAL INDUSTRY LTD. Trade name)
PETA-K (pentaerythritol tetraacrylate, Daicel Cytec's trade name)
Biscoat # 192 (phenoxyethyl acrylate, trade name of Osaka Organic Chemical Industry Co., Ltd., abbreviated as “PEA” in Table 1)
(Photopolymerization initiator)
IRGACURE 819 (trade name, manufactured by BASF, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, solid content: 100%, abbreviated as “819” in Table 1)
DAROCURE TPO (trade name, manufactured by BASF, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, solid content 100%, abbreviated as “TPO” in Table 1)
[Slip agent]
Silicone surface conditioner BYK-UV3500 (polydimethylsiloxane having a polyether-modified acrylic group, trade name by BYK, abbreviated as “UV3500” in Table 1)
(Polymerization inhibitor)
P-methoxyphenol (KANTO CHEMICAL CO., INC, abbreviated as “MEHQ” in Table 1)
[Pigment]
R-630 (titanium oxide, trade name of ISHIHARA SANGYO KAISHA, LTD., Abbreviated as “Ti oxide” in Table 1)
[Dispersant]
Solsperse 36000 (trade name of LUBRIZOL, abbreviated as Sol 36000 in Table 1)

〔Base material〕
Base material 1 (package base material): Epoxy resin surface 1 (manufactured by Sharp Corporation, surface mount package, model number “P-LFBGA048-0606”)
Base material 2 (package base material): Epoxy resin surface 2 (manufactured by ROHM, serial EEPROM, model number “BR24L01A”)
Base material 3 (semiconductor base material): silicon surface 1 (manufactured by Shin-Etsu Chemical Co., Ltd., 300 mm silicon wafer)
Base material 4 (semiconductor base material): silicon surface 2 (manufactured by SUMCO, SOI wafer)
In addition, the said base material 3 and the base material 4 used what formed the circuit and diced into the semiconductor chip. During circuit formation, the thickness of the silicon oxide layer on the wafer surface was 50 nm.

[Examples 1-17, Comparative Examples 1-4]
[Preparation of radiation-curable inkjet ink]
The components described in Table 1 and Table 2 below were added so as to have the composition (unit: mass%) described in Table 1 and Table 2, and this was mixed and stirred at room temperature for 1 hour to be completely dissolved. This was further filtered through a 5 μm membrane filter to obtain each radiation curable inkjet ink.

[Preparation of ink coating film]
(System 1)
Each of the substrates 1 to 4 was pretreated by irradiating with a low-pressure mercury lamp. According to the combination of ink and base material shown in Table 1 and Table 2, on each base material subjected to pretreatment using an ink jet printer (PX-7550S [trade name], manufactured by Seiko Epson Corporation) A solid pattern image was printed so that the thickness of the printed material (image) was 10 μm. The solid pattern image is an image in which dots are recorded for all the pixels that are the minimum recording unit area defined by the recording resolution.
Thereafter, each substrate was heated at 190 ° C. for 20 minutes without irradiation with radiation to obtain a recorded matter.

(System 2)
Each of the substrates 1 to 4 was pretreated by irradiating a low-pressure mercury lamp. According to the combination of the ink and the base material shown in Table 1 and Table 2, a printed matter (image) ) Was printed so that the film thickness was 10 μm, and the ink was cured by irradiating radiation under the following conditions to obtain a recorded matter. Radiation irradiation conditions were a wavelength of 395 nm, an irradiation intensity of 400 mW / cm ² , and a maximum integrated irradiation amount of 2,400 mJ / cm ² .

(System 3)
Each of the substrates 1 to 4 was pretreated under low pressure mercury. According to the combination of the ink and the base material shown in Table 1 and Table 2, an ink jet printer (PX-7550S [trade name], manufactured by Seiko Epson Corporation) is used to form a printed film on each base material that has been pretreated. While printing a solid pattern image having a thickness of 10 μm, the ink was cured by irradiating with radiation under the following conditions. Radiation irradiation conditions were a wavelength of 395 nm, an irradiation intensity of 400 mW / cm ² , and a maximum integrated irradiation dose of 450 mJ / cm ² .
Then, each said base material was heated at 130 degreeC for 60 minute (s), and the recorded matter was obtained.

(System 4)
A recorded matter was obtained in the same manner as in System 3 except that the heating condition was 160 ° C. for 70 minutes.

(System 5)
A recorded matter was obtained in the same manner as in System 3 except that the heating condition was 190 ° C. for 10 minutes.

(System 6)
A recorded matter was obtained in the same manner as in System 3 except that the heating condition was 160 ° C. for 10 minutes.

(System 7)
A recorded matter was obtained in the same manner as in System 3 except that the heating condition was 190 ° C. for 70 minutes.

(System 8)
A recorded matter was obtained in the same manner as in System 3 except that the heating condition was 160 ° C. for 80 minutes.

(System 9)
A recorded matter was obtained in the same manner as in System 3 except that the heating condition was 190 ° C. for 4 minutes.

(System 10)
A recorded matter was obtained in the same manner as in the system 3 except that the heating condition was 230 ° C. for 20 minutes.

[Evaluation item]
About the recorded matter obtained by the above system 1 to system 6, that is, in which the ink is recorded on the package substrate or the semiconductor substrate to form a coating film, the following evaluation (adhesion, abrasion resistance, and Alcohol resistance) was performed at room temperature.

[Adhesion]
According to JIS K-5600-5-6 (ISO 2409) (Coating General Test Method-Part 5: Mechanical Properties of Coating Film-Section 6: Adhesion (Crosscutting Method)) Evaluation of adhesion between No. 4 and an image formed by solid printing was performed. Here, the cross-cut method will be described.
As a cutting tool, a single blade cutting tool (a cutter that is generally commercially available) and a guide for cutting at equal intervals using a single blade cutting tool were prepared.
First, the cutting tool blade was applied so as to be perpendicular to the coating film, and six cuts were made in the recorded matter. After making these six cuts, the direction of 90 ° was changed, and another six cuts were made so as to be perpendicular to the cuts already made.
Next, take out the transparent adhesive tape (width 25 ± 1 mm) so that the length is about 75 mm, attach the tape to the grid-cut portion formed on the coating film, and finger enough to see through the coating film. I rubbed the tape. Next, within 5 minutes of adhesion, it was reliably pulled apart at an angle close to 60 ° in 0.5 to 1.0 seconds.
The evaluation criteria are as follows. ◎ and ○ are practically acceptable evaluation criteria. The evaluation results are shown in Tables 3 and 4.
A: There is no peeling in the eyes of any lattice.
○: Peeling is observed on a part of the lattice (less than 50%).
Δ: Peeling is observed in 50% or more of the lattice.
X: Peeling is recognized on the entire surface.

[Abrasion resistance]
The degree of peeling of the coating film was confirmed using a load fluctuation type frictional wear test system (Tribogear TYPE-HHS2000 [trade name], manufactured by Shinto Kagaku Co., Ltd.). Conditions were set to a load of 300 gf, an image formed by solid printing with a sapphire needle of Φ0.2 mm was scratched, and the degree to which the coating film was peeled was confirmed.
The evaluation criteria are as follows. ◎ and ○ are practically acceptable evaluation criteria. The evaluation results are shown in Tables 3 and 4.
(Double-circle): A coating film has neither a crack nor peeling.
○: A part of the coating film is scratched, but no peeling is observed.
(Triangle | delta): A part of coating film is damaged and a coating film peels.
X: The entire surface of the coating film is scratched and the coating film is peeled off.

[Alcohol resistance]
The obtained recorded matter was immersed in an isopropyl alcohol solution for 15 minutes. Thereafter, the film was taken out from the solution, and the degree to which the coating film was peeled was confirmed under the same conditions as in the above-described evaluation of abrasion resistance.
The evaluation criteria are as follows. ◎ and ○ are practically acceptable evaluation criteria. The evaluation results are shown in Tables 3 and 4.
(Double-circle): A coating film has neither a crack nor peeling.
○: A part of the coating film is scratched, but no peeling is observed.
(Triangle | delta): A part of coating film is damaged and a coating film peels.
X: The entire surface of the coating film is scratched and the coating film is peeled off.

  From the said Table 3 and Table 4, the radiation which heat-processed at 150-200 degreeC after containing 5-20 mass% N-vinyl caprolactam, adhering on a package base material or a semiconductor base material, and irradiating with radiation. It has been found that the curable ink-jet ink is excellent in all of abrasion resistance, adhesion, and alcohol resistance.

Claims (6)

A discharge step of discharging radiation curable inkjet ink onto a package substrate or a semiconductor substrate;
A curing step of irradiating the ejected ink with radiation to cure the ink;
A heating step of heating a cured product obtained by curing at 150 to 200 ° C .;
An ink jet recording method comprising:
The radiation-curable ink-jet ink comprises 5 to 20 % by mass of N-vinylcaprolactam with respect to the total mass of the ink, and 5 to 20% by mass of a polyfunctional acrylate with respect to the total mass of the ink,
The package base material encloses a semiconductor chip, and the material of the package base material is at least one of epoxy resin, phenol resin, silicon resin, polyimide, and polymethyl methacrylate.
Inkjet recording method.   The inkjet recording method according to claim 1, wherein the polyfunctional acrylate is a polyfunctional acrylate having a pentaerythritol skeleton. A discharge step of discharging radiation curable inkjet ink onto a package substrate or a semiconductor substrate;
A curing step of irradiating the ejected ink with radiation to cure the ink;
A heating step of heating a cured product obtained by curing at 150 to 200 ° C. for 10 to 75 minutes;
An ink jet recording method comprising:
The radiation curable inkjet ink contains 5 to 20% by mass of N-vinylcaprolactam based on the total mass of the ink;
The package base material encloses a semiconductor chip, and the material of the package base material is at least one of epoxy resin, phenol resin, silicon resin, polyimide, and polymethyl methacrylate.
Inkjet recording method. A discharge step of discharging radiation curable inkjet ink onto a package substrate or a semiconductor substrate;
A curing step of irradiating the ejected ink with radiation to cure the ink;
A heating step of heating a cured product obtained by curing at 150 to 200 ° C .;
An ink jet recording method comprising:
The radiation curable inkjet ink contains 5 to 20% by mass of N-vinylcaprolactam based on the total mass of the ink;
The radiation to be irradiated has an emission peak wavelength in a range of 350 to 405 nm, an integrated irradiation amount is 100 mJ / cm ² or more,
The package base material encloses a semiconductor chip, and the material of the package base material is at least one of epoxy resin, phenol resin, silicon resin, polyimide, and polymethyl methacrylate.
Inkjet recording method.   A radiation-curable ink-jet ink for use in the ink-jet recording method according to claim 1.   A package base material or a semiconductor base material as a recording medium, and a cured product of a radiation curable inkjet ink recorded on the package base material or the semiconductor base material, and any one of claims 1 to 4. A recorded matter obtained by the inkjet recording method described in the item.