JP2001019740A - High-energy ray photosensitive cationic curing type encapsulant and connection and sealing of integrated circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject encapsulant capable of forming collective bumping holes by a photolithographic method and exhibiting excellent resolution, adhesion, etc., by using a specific high-energy ray photosensitive cationic curing type encapsulant. SOLUTION: This encapsulant comprises (A) a high-energy ray photosensitive cationic curing type resin, (B) a cationc photopolymerization initiator and (C) a curing component. The component A is preferably a reactional product of a reactional product of an epoxy resin having at least >=2 epoxy groups in the molecule (preferably an epoxy resin which is a reactional product of a bisphenol type epoxy resin with an epihalohydrin and having 280-500 g/equivalent epoxy equivalent or the like) with an alcoholic hydroxyl group-containing monocarboxylic acid compound (preferably dimethylolpropionic acid or the like) with a polybasic acid anhydride (preferably succinic anhydride or the like). The encapsulant can be used to simultaneously carry out connection and sealing in substrate packaging of flip-chips.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of connecting an integrated circuit element to connect fine electrode pads of the integrated circuit element and electrode terminals provided on a mounting printed circuit board, and more particularly to a flip chip (hereinafter referred to as FC). The present invention relates to a high-energy radiation-sensitive cation-curable sealant capable of simultaneously performing connection and sealing in mounting on a substrate.

[0002]

2. Description of the Related Art Surface mount technology (SMT) and surface mount device (SMD) enable high-density mounting of integrated circuits on a printed circuit board. In addition, a reduction in the interconnection leads to an improvement in reliability, and a reduction in mounting materials, processing costs, and the like. Therefore, a large number of printed boards adopting these technologies have been increasing.

Conventionally, when FC is connected to a printed circuit board, a method of using an anisotropic conductive material for electrical connection containing conductive particles and thermocompressing it at 180 to 200 ° C. at about 20 to 30 kg per square centimeter. Has been adopted. However, according to this method, when the number of conductive particles increases or the number of electrode pads of the integrated circuit element increases, there is a risk of short-circuiting between adjacent electrode pads or electrode terminals or current leakage. In addition, since a circuit is formed by the contact of the conductive particles, there is a disadvantage that when the contact is not made well, the contact resistance increases, and in the worst case, the current stops flowing.

On the other hand, in a method of connecting an integrated circuit via a metal bump, an electrode pad formed on the integrated circuit element and an electrode terminal on a printed wiring board formed corresponding to the pad are provided. Using a non-photosensitive adhesive for connection between the substrate and a printed wiring board has also been proposed. At this time, a hole is physically formed using a laser beam or the like in accordance with the bump hole. However, in the future,
The number of C electrode pads is increasing, and there is a disadvantage that the cost of the integrated circuit element increases if the bump holes are physically formed.

[0005]

As means for solving such problems, means for forming a bump hole by collective irradiation of light is described in JP-A-6-21149. According to this method, even if there are a large number of bump holes, they can be formed by a photolithographic method, which is advantageous in terms of cost. However, since an acrylate material is used, resolution, heat resistance, and water resistance are improved. And the sealing property of the semiconductor is inferior. In addition, when used for connection of FC for recent chip size packaging (CSP), there is a problem that the connection is large and connection failure occurs.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, by using a specific high-energy radiation-sensitive cation-curable sealant, a photolithography method has been used. An optical patterning encapsulant capable of collectively forming bump holes, having excellent resolution, adhesiveness, heat resistance, water resistance and low curing shrinkage was found, and the present invention was completed. That is, the present invention provides (1) a high-energy radiation-sensitive cationically curable resin comprising a high-energy radiation-sensitive cationically curable resin (A), a cationic photopolymerization initiator (B), and a curing component (C). Mold sealant, (2)
A high-energy radiation-sensitive cationically curable resin (A) is obtained by reacting an epoxy resin (a) having at least two or more epoxy groups in a molecule with an alcoholic hydroxyl group-containing monocarboxylic acid compound (b) and a polybasic. (1) a high-energy radiation-sensitive cation-curable sealing agent according to (1), which is a reaction product with an acid anhydride (c); (3) an epoxy resin having at least two epoxy groups in a molecule (a) Is a reaction product of a bisphenol type epoxy resin and an epihalohydrin and has an epoxy equivalent of 280 to 500 g / equivalent, an epoxy resin or a novolak type epoxy resin having an epoxy equivalent of 150 to 250 g / equivalent. Epoxy resin of a condensate of an aromatic aldehyde compound and an epoxy equivalent of 150 to
The high-energy radiation-sensitive cation-curable sealant according to (2), wherein the epoxy resin is 250 g / equivalent of an epoxy resin.

(4) The high-energy radiation-sensitive cation-curable encapsulation according to (2) or (3), wherein the alcoholic hydroxyl group-containing monocarboxylic acid compound (b) is dimethylolpropionic acid or dimethylolbutanoic acid. Agent, (5)
The high energy ray exposure according to any one of (2) to (4), wherein the addition ratio of the alcoholic hydroxyl group-containing monocarboxylic acid (b) is 10 to 70 equivalent% of the epoxy equivalent of the epoxy resin (a). (6) polybasic acid anhydride (c) is succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride,
The high acid according to any one of (2) to (5), which is one or more polybasic anhydrides selected from maleic anhydride, trimellitic anhydride, and pyromellitic anhydride. Energy ray-sensitive cationic curing type sealant, (7)
The high-energy radiation-sensitive resin according to any one of (1) to (6), wherein the solid content acid value of the high-energy radiation-sensitive cationically curable resin (A) is in the range of 50 to 150 mg · KOH / g. (8) A printed board having a high-energy radiation-sensitive cation-curable sealant layer according to any one of (1) to (7),

(9) An integrated circuit connection sealing method for connecting and sealing via a metal bump between an electrode pad formed on an integrated circuit element and an electrode terminal on a printed wiring board formed corresponding to the pad. 3. A method of connecting and sealing an integrated circuit according to claim 1, wherein a high-energy radiation-sensitive cation-curable sealing agent is used to seal the connection between the integrated circuit element and the printed wiring board. (10) a) a step of forming a metal bump on at least one of the electrode pad and the electrode terminal; and a) a step of applying a high-energy radiation-sensitive cation-curable sealant to at least one of the integrated circuit element side and the substrate side surface. , C)
Exposing the high-energy radiation-sensitive cation-curable sealant to portions other than the electrode pads or electrode terminals with high-energy radiation; d) irradiating infrared rays or baking in a heating furnace; Removing the unexposed portion by using: f) irradiating the cured film of the high-energy radiation-sensitive cation-curable sealant with high-energy radiation, if necessary; g) facing the electrode pads and the electrode terminals, Providing an integrated circuit element on a substrate, comprising the steps of: bonding an electrode pad or an electrode terminal facing the metal bump and then bonding the two electrode surfaces by thermocompression bonding. Connection sealing method, (11) the high-energy radiation-sensitive cation-curable sealing agent according to any one of (1) to (7), wherein the high-energy radiation-sensitive cation-curing sealing agent is (9) Or to provide a connection sealing method, an integrated circuit according to (10).

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The high-energy radiation-sensitive cationically curable sealant of the present invention comprises a high-energy radiation-sensitive cationically curable resin (A), a cationic photopolymerization initiator (B) and a curing component (C). It contains. As the high-energy radiation-sensitive cationically curable resin (A), for example, a reaction product of an epoxy resin (a) having at least two or more epoxy groups in a molecule and an alcoholic hydroxyl group-containing monocarboxylic acid compound (b) may be used. A reaction product with the polybasic acid anhydride (c) is preferred.

As the epoxy resin (a) having at least two epoxy groups in the molecule, for example, an epoxy resin having an epoxy equivalent of 150 to 500 g / equivalent is preferable. Specifically, for example, an epoxy resin which is a reaction product of a bisphenol type epoxy resin and epihalohydrin and has an epoxy equivalent of 280 to 500 g / equivalent, a novolak type epoxy resin and an epoxy equivalent of 150
Epoxy resin of 〜250 g / equivalent or epoxy resin of a condensate of a phenol compound and an aromatic aldehyde compound having an epoxy equivalent of 150 to 250 g / equivalent.

Examples of the alcoholic hydroxyl group-containing monocarboxylic acid compound (b) include monomethylolpropionic acid, dimethylolpropionic acid, monomethylolbutanoic acid and dimethylolbutanoic acid. The acid compound (b) can be used alone or as a mixture of two or more. Particularly, the epoxy group of the epoxy resin (a) and the monocarboxylic acid (b)
And dimethylolpropionic acid and dimethylolbutanoic acid, which can introduce a large number of alcoholic hydroxyl groups capable of reacting with the polybasic acid anhydride (c) described below to a compound obtained by reacting The addition ratio of the alcoholic hydroxyl group-containing monocarboxylic acid compound (b) is preferably 10 to 70 equivalent% of the epoxy equivalent of the epoxy resin (a). When the addition ratio is less than 10 equivalent%, the amount of the alcoholic hydroxyl group generated or introduced is low, the introduction amount of the polybasic acid anhydride (c) is low, and the developability of the aqueous alkali solution is reduced. On the other hand, when the addition ratio exceeds 70 equivalent%, the amount of the remaining epoxy groups decreases, and the cationic curability becomes insufficient, which is not preferable.

Examples of the polybasic acid anhydride (c) include succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride and the like. One or more selected polybasic acid anhydrides may be mentioned. These polybasic acid anhydrides (c) can be used alone or in combination of two or more. The polybasic acid anhydride (c) is half-esterified by adding to the hydroxyl group generated or introduced by the reaction between the epoxy resin (a) and the alcoholic hydroxyl group-containing monocarboxylic acid compound (b) to form a carboxylic acid I do. The generated carboxylic acid is indispensable for imparting developability to an aqueous alkali solution, and the solid carboxylic acid of the polycarboxylic acid resin (A) of the present invention is adjusted to be 50 to 150 mg · KOH / g. Is preferred. Acid value of solid content is 50mg · KOH /
If the amount is less than g, the developability of the resin composition described later in an aqueous alkali solution is significantly reduced, and in the worst case, development becomes impossible, which is not preferable. On the other hand, the solid content acid value is 150 mg KOH
If the ratio exceeds / g, the developability of the aqueous alkali solution is too high, and the adhesiveness for development may be reduced. In the worst case, the pattern may not be obtained.

The reaction between the epoxy resin (a) and the alcoholic hydroxyl group-containing monocarboxylic acid compound (b) is carried out by a solvent having no hydroxy group, for example, ketones such as acetone, ethyl methyl ketone and cyclohexanone, benzene, toluene, Aromatic hydrocarbons such as xylene and tetramethylbenzene, glycol ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dipropylene glycol dimethyl ether and dipropylene glycol diethyl ether, ethyl acetate, butyl acetate, methyl cellosolve acetate, and ethyl cellosolve Acetate, butyl cellosolve acetate,
The reaction is carried out in organic solvents such as esters such as carbitol acetate and propylene glycol monomethyl ether acetate, and petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha. At the time of the reaction, it is preferable to use a catalyst to promote the reaction, and the amount of the catalyst is 0.1 to 10% by weight based on the reaction raw material mixture. The reaction temperature at that time is 60 ~
150 ° C. and the reaction time is preferably 5-60
Time. Examples of the catalyst used in this reaction include triethylamine, benzyldimethylamine, triethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium iodide, triphenylphosphine, triphenylstibine, methyltriphenylstibine, chromium octanoate, octane Zirconium acid and the like.

In the reaction of the reaction product of the epoxy resin (a) with the alcoholic hydroxyl group-containing monocarboxylic acid compound (b) and the polybasic acid anhydride (c), the acid value of the solid component after the reaction is in the above-mentioned range. It is obtained by reacting a calculated amount such that the amount represented by The reaction temperature at that time is 60 to 15
0 ° C. is preferred, and the reaction time is 1 to 10 hours. The use ratio of the high-energy radiation-sensitive cation-curable resin (A) thus obtained is such that the solid content of the sealant is 100%.
In terms of parts by weight, it is preferably 30 to 90 parts by weight, particularly preferably 40 to 80 parts by weight.

The cationic photopolymerization initiator (B) used in the high-energy radiation-sensitive cationic curable adhesive of the present invention.
Is an epoxy group that generates a Bronsted acid or a Lewis acid by irradiating energy rays such as visible light, ultraviolet rays, X-rays, and electron beams, and remains on the high-energy radiation-sensitive cation-curable resin (A). Initiates the polymerization reaction of Examples of the cationic photopolymerization initiator (B) include a diazonium salt, a sulfonium salt, and an iodonium salt. Specifically, benzenediazonium hexafluoroantimonate, benzenediazonium hexafluorophosphate, benzenediazonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium tetrafluoroborate, 4, 4′-bis [bis (2-hydroxyethoxyphenyl) sulfonio] phenyl sulfide bishexafluorophosphate,
Examples thereof include diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluorophosphate, diphenyliodonium-tetrakis (pentafluorophenyl) borate, and diphenyl-4-thiophenoxyphenylsulfonium hexafluorophosphate. A detailed description of the cationic photopolymerization can be found in “Photopolymerization Technology”, edited by Nikkan Kogyo Shimbun, “Photopolymer Technology: Ao Yamaoka, Ed.

Commercial products of the cationic photopolymerization initiator (B) include, for example, Kayarad PCI-220 and Kayarad P
CI-620 (trade names: all manufactured by Nippon Kayaku), UVI
-6990 (trade name: manufactured by Union Carbide), Adeka Optomer SP-150, Adeka Optomer SP-17
0 (trade names: all manufactured by Asahi Denka), CIT-1370,
CIT-1682, CIP-1866S, CIP-20
48S, CIP-2064S (trade names: all manufactured by Nippon Soda), DPI-101, DPI-102, DPI-1
03, DPI-105, MPI-103, MPI-10
5, BBI-101, BBI-102, BBI-10
3, BBI-105, TPS-101, TPS-10
2, TPS-103, TPS-105, MDS-10
3, MDS-105, DTS-102, DTS-103
(Trade names: all manufactured by Midori Kagaku).

The amount of the cationic photopolymerization initiator (B) used is
When the solid content of the adhesive is 100 parts by weight, it is preferably 1 to 20 parts by weight, particularly preferably 1 to 15 parts by weight. Further, if necessary, anthracene, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, 2-ethyl-
9,10-diethoxyanthracene, 2-ethyl-9,
10-dipropoxyanthracene, fluorene, pyrene, stilbene, 4'-nitrobenzyl-9,10-dimethoxyanthracene-2-sulfonate, 4'-nitrobenzyl-9,10-diethoxyanthracene-2-
A sensitizer such as sulfonate, 4'-nitrobenzyl-9,10-dipropoxyanthracene-2-sulfonate can be used in combination. The use amount of these sensitizers is 1 to 200% by weight, more preferably 5 to 150% by weight, based on the cationic photopolymerization initiator (B).

The curing component (C) used in the high-energy radiation-sensitive cation-curable adhesive of the present invention reacts thermally with carboxyl groups during heating and curing after exposure and development, and the cured coating film has alkali resistance. It imparts solvent resistance, heat resistance, and electrical insulation. As the curing component (C), for example, phenol novolak type epoxy resin, cresol novolak type epoxy resin, trishydroxyphenylmethane type epoxy resin, dicyclopentadiene phenol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenol Type epoxy resin, bisphenol A novolak type epoxy resin, naphthalene skeleton-containing epoxy resin, heterocyclic epoxy resin, and the like.

Examples of the phenol novolak type epoxy resin include Epiclon N-770 (manufactured by Dainippon Ink and Chemicals, Inc.); E. FIG. N438 (manufactured by Dow Chemical Company), Epicoat 154 (Yukaka Epoxy Co., Ltd.)
And RE-306 (manufactured by Nippon Kayaku Co., Ltd.). Examples of the cresol novolak type epoxy resin include Epicron N-695 (manufactured by Dainippon Ink and Chemicals, Inc.), EOCN-102S, and EOCN-103.
S, EOCN-104S (Nippon Kayaku Co., Ltd.), UVR
-6650 (manufactured by Union Carbide), ESCN-1
95 (manufactured by Sumitomo Chemical Co., Ltd.).

Examples of the trishydroxyphenylmethane type epoxy resin include TACTICX-742 (manufactured by Dow Chemical Company) and Epicoat E1032H60 (manufactured by Yuka Shell Epoxy Co., Ltd.). Examples of the dicyclopentadiene phenol type epoxy resin include Epicron EXA-7200 (manufactured by Dainippon Ink and Chemicals, Inc.) and TACTIX-556 (manufactured by Dow Chemical Company).

As the bisphenol type epoxy resin,
For example, Epicoat 828, Epicoat 1001 (manufactured by Yuka Shell Epoxy), UVR-6410 (manufactured by Union Carbide), D.C. E. FIG. Bisphenol A type epoxy resin such as R-331 (manufactured by Dow Chemical Company), YD-8125 (manufactured by Toto Kasei), bisphenol such as UVR-6490 (manufactured by Union Carbide), YDF-8170 (manufactured by Toto Kasei) F-type epoxy resins and the like can be mentioned.

Examples of the biphenol type epoxy resin include a bixylenol type epoxy resin of YX-4000 (manufactured by Yuka Shell Epoxy) and YL-6121 (manufactured by Yuka Shell Epoxy). Examples of bisphenol A novolak type epoxy resin include Epiclon N-880 (manufactured by Dainippon Ink and Chemicals, Inc.),
Epicoat E157S75 (Yukaka Epoxy Co., Ltd.)
Manufactured).

Examples of the naphthalene skeleton-containing epoxy resin include NC-7000 (manufactured by Nippon Kayaku) and EXA-
4750 (manufactured by Dainippon Ink and Chemicals, Inc.). As the alicyclic epoxy resin, for example, EHPE-
3150 (manufactured by Daicel Chemical Industries, Ltd.). As the heterocyclic epoxy resin, for example, TEPI
C, TEPIC-L, TEPIC-H, TEPIC-S
(All manufactured by Nissan Chemical Industries, Ltd.).

The curing component (C) is used singly or as a mixture of two or more types. The amount of the curing component (C) contained in the adhesive of the present invention is as follows when the solid content of the adhesive is 100 parts by weight. The amount is preferably 1 to 50 parts by weight, and particularly preferably 3 to 50 parts by weight.
45 parts by weight.

The composition of the present invention may further comprise barium sulfate, barium titanate, silicon oxide powder, finely divided silicon oxide, amorphous silica for the purpose of improving properties such as coating suitability, heat resistance, adhesion and hardness. , Talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, mica powder, Teflon powder and the like can be used.
The amount is preferably 60 parts by weight or less, particularly preferably 5 to 40 parts by weight, based on 100 parts by weight of the solid content of the composition of the present invention.

Further, if necessary, coloring agents such as phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, titanium oxide, carbon black, and naphthalene black; asbestos, orben, benton, montmorillonite, etc. Appropriate amounts of additives such as thickeners, silicone-based, fluorine-based, polymer-based antifoaming agents and / or leveling agents can be added.

The high-energy radiation-sensitive cationically curable sealant of the present invention comprises the components (A), (B) and (C), and if necessary, the above-mentioned fillers or additives. And uniformly mixed with a roll mill, etc.
It can be obtained as a liquid product by dissolving or dispersing. In addition, a solvent may be used together if desired, mainly for adjusting the viscosity. This solvent may be a solvent used in the production of the components. Examples of the solvent include ketones such as acetone, ethyl methyl ketone and cyclohexanone, aromatic hydrocarbons such as benzene, toluene, xylene and tetramethylbenzene, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dipropylene glycol dimethyl ether and dipropylene. Glycol ethers such as glycol diethyl ether, ethyl acetate,
Esters such as butyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, propylene glycol monomethyl ether acetate, petroleum ether,
Examples include petroleum solvents such as petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha, and organic solvents such as γ-butyrolactone.

The liquid composition is coated on a base film (release film) using a roll coater, a doctor bar, a wire bar method, a dipping method, a spin coating method, a gravure method, a doctor blade method, or the like. After that, the film is dried in a drying oven set at 60 to 100 ° C. to remove a predetermined amount of the solvent, and if necessary, a release film or the like may be attached to form a dry film. At this time, the thickness of the resist on the base film is adjusted to 15 to 150 μm. As the base film, a film of polyethylene terephthalate, polypropylene, or the like is suitably used. In order to use this dry film, for example, the release film may be peeled off, transferred to a substrate, and exposed, developed, and heated in the same manner as described above.

To cure the high-energy radiation-sensitive cation-curable sealant of the present invention, visible light, ultraviolet light, X
Irradiation with an energy beam such as a beam or an electron beam may be performed. For example, when irradiating ultraviolet rays, an ultraviolet generator such as a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, and an ultraviolet light emitting laser (for example, an excimer laser) may be used.

According to the method for sealing connection of an integrated circuit of the present invention, an electrode pad formed on an integrated circuit element and an electrode terminal on a printed wiring board formed corresponding to the pad are connected and sealed via a metal bump. In the method for sealing a connection of an integrated circuit to be stopped, a high-energy radiation-sensitive cation-curing type sealing agent is used for sealing a connection between an integrated circuit element and a printed wiring board. Here, the term “connection sealing” refers to connecting an electrode pad and an electrode terminal via a metal bump and sealing the entire connection surface.

The details of this connection sealing method will be described below.
That is, after a metal bump is formed at a desired position on a substrate provided with an electrode element or an integrated circuit element provided with an electrode pad in advance, at least one of the integrated circuit element side and the substrate side surface is exposed to high energy radiation. Spin coating method, roll coating method,
The film is applied by a curtain coating method or the like, or a film is formed by thermocompression bonding of a dry film having a layer of the high-energy radiation-sensitive cation-curable sealing agent of the present invention. Thereafter, a portion other than the electrode pads or the electrode terminals corresponding to the metal bump portions is collectively exposed to high-energy rays such as ultraviolet rays via a mask pattern to photo-decompose the cationic photopolymerization initiator (B) and cure the catalyst. Generate. Next, in order to accelerate the curing of the high-energy radiation-sensitive cation-curable resin (A) and / or the curing component (C), 60 to 12
After a heat treatment at a temperature of 0 ° C. for 5 to 30 minutes, an aqueous solution of an inorganic alkali such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium metasilicate, tetramethyl hydroxide, triethanolamine, diethanolamine Unexposed portions are removed using an aqueous solution of an organic alkali such as choline to obtain bump holes. Then, if necessary, irradiate the entire surface of the cured film of the high-energy radiation-sensitive cation-curable adhesive with high-energy radiation, face the electrode pads to the electrode terminals, and solder, gold, aluminum, copper, indium, ITO, or another metal. The electronic element can be assembled on the substrate by thermocompression bonding after aligning the electrode pad or electrode terminal facing the bump. Examples of the high-energy radiation-sensitive cation-curable sealant used herein include the above-described high-energy radiation-sensitive cation-curable sealant of the present invention. Also,
The film thickness of the high-energy radiation-sensitive cationic curing type sealant is
Although it depends on the thickness of the metal bump, it is usually 10 to 150
It is about μm.

[0032]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples, but it should not be construed that the invention is limited thereto.

(Synthesis of High Energy Radiation Photosensitive Cationic Curable Resin (A)) Synthesis Example 1 propylene glycol monomethyl ether acetate (328.0 g) as a reaction solvent in a 5 L flask, and NER having an epoxy equivalent of 297.8 as an epoxy resin (a) −70
107 (trade name: Nippon Kayaku epoxy resin: epoxy resin obtained by reacting bisphenol-F type epoxy resin with epichlorohydrin) and 1070.8 g
The mixture was heated to 0 ° C. to dissolve the resin. To this resin solution, 241.1 g of dimethylolpropionic acid (addition ratio: 50 equivalent%) as the alcoholic hydroxyl group-containing monocarboxylic acid compound (b) and 4.92 g of triphenylphosphine as the reaction catalyst were added, and the mixture was heated to 100 ° C. The reaction was performed for 18 hours. After confirming that the acid value of the reaction solution was 1 mg · KOH / g or less, 3.6 g of cumyl hydroperoxide was added.
In addition, the mixture was heated at a temperature of 100 ° C. for 1 hour to oxidize triphenylphosphine used as a catalyst to eliminate the catalytic activity. Next, 488.1 g of tetrahydrophthalic anhydride and 872.0 g of propylene glycol monomethyl ether acetate were added to the reaction solution as polybasic anhydride (c), and 10
The reaction was carried out at a temperature of 0 ° C. for 10 hours to obtain a high-energy radiation-sensitive cation-curable resin (A). Solid content is 60%
When the acid value of the solid content was measured, it was 110 mg · K.
OH / g. This resin solution is designated as (A-1).

Synthesis Example 2 296.1 g of propylene glycol monomethyl ether acetate as a reaction solvent and EPPN-5 having an epoxy equivalent of 180.0 as an epoxy resin (a) were placed in a 3 L flask.
03 (trade name: Nippon Kayaku epoxy resin: epoxy resin of a condensate of phenol and benzaldehyde)
2.9 g was charged and heated to 70 ° C. to dissolve the resin. To this resin solution was added dimethylolpropionic acid as an alcoholic hydroxyl group-containing monocarboxylic acid compound (b).
5 g (addition rate: 50 equivalent%), 4.44 g of triphenylphosphine as a reaction catalyst were added, and the mixture was heated to 100 ° C.
The reaction was performed for 8 hours. The acid value of the reaction solution is 1mg · KOH / g
After confirming the following, 3.2 g of cumyl hydroperoxide was added, and the mixture was heated at a temperature of 100 ° C. for 1 hour.
Triphenylphosphine used as a catalyst was oxidized to lose catalytic activity. Next, the polybasic acid anhydride (c) is added to the reaction solution.
440.6 g of tetrahydrophthalic anhydride, propylene glycol monomethyl ether acetate 578.
9 g was added and the mixture was reacted at a temperature of 100 ° C. for 10 hours to obtain a high-energy radiation-sensitive cationically curable resin (A). The solid content was 65%, and the acid value of the solid content was measured.
It was 107 mg · KOH / g. This resin solution is referred to as (A
-2).

Examples 1 and 2 Each component was blended according to the blending composition shown in Table 1 (the numerical values are parts by weight) and kneaded with a three-roll mill to obtain the high-energy radiation-sensitive cationic curing type sealant of the present invention. Prepared. This was placed on a polyethylene terephthalate film (hereinafter abbreviated as PET) so that the film thickness after drying would be 30 microns.
It was applied using a bar coater. Thereafter, the film was dried in a hot-air drying oven at 80 ° C. for 20 minutes to obtain a film having a high-energy radiation-sensitive cation-curable adhesive layer of the present invention. Next, this film is pasted on a polyimide-based printed circuit board on which electrode terminals of 100 micron pitch are formed in advance through a hot roll at 80 ° C., and then, via a mask pattern, to portions other than the electrode terminals. UV irradiation was performed. Next, the printed circuit board is accelerated in a hot air drying oven at 80 ° C. for 10 minutes to accelerate the curing reaction.
T was peeled off and developed with a 0.1% aqueous solution of tetramethylammonium hydroxide to remove unexposed portions. After washing with pure water and drying sufficiently, the entire surface was irradiated with ultraviolet rays. About the obtained cured film, developability, resolution,
A test was performed for sensitivity. Table 2 shows the results.

On a printed circuit board having a cured material layer of the sealing agent, an FC having a 90-micron pitch metal bump formed on an electrode pad is put together with a corresponding electrode terminal, and is placed in a vacuum at 150 ° C. At a temperature, a load of 5 kg was applied per square centimeter to melt and bond the cured layer of the adhesive. The obtained device was tested for adhesiveness, contact resistance, and insulation. Table 2 shows the results. The evaluation results were based on the following criteria.

(Developability) The following evaluation criteria were used.・: At the time of development, the ink was completely removed and development was possible. ×: Some parts are not developed during development. (Resolution) A 50 μm negative pattern is adhered to the dried coating film, and the coating film is exposed to ultraviolet light having an integrated light amount of 200 mJ / cm ² . Next, with a 1% aqueous solution of sodium carbonate for 60 seconds,
Develop with a spray pressure of 2.0 kg / cm ² and observe the transfer pattern with a microscope. The following criteria were used:・: The pattern edge is a straight line and is resolved. X: Peeling or pattern edges are jagged.

(Sensitivity) A step tablet (manufactured by Kodak Co., Ltd.) was brought into close contact with the dried coating film, and the integrated light amount was 500
Irradiation exposure with ultraviolet rays of mJ / cm ² is performed. Next, the film is developed with a 1% aqueous sodium carbonate solution for 60 seconds at a spray pressure of 2.0 kg / cm ² , and the number of steps of the coating film left undeveloped is confirmed. The following criteria were used: ○ ・ ・ ・ ・ ・ ・ 8 steps or more × ・ ・ ・ ・ 7 steps or less (Adhesion) Attach a cylindrical jig to the back surface of the substrate and FC with an adhesive at a speed of 10 mm / min (room temperature). A tensile test was performed. The strength at the time when FC is peeled from the substrate is confirmed. The following criteria were used: ○ ・ ・ ・ ・ ・ ・ 5kg / cm ² or more × ・ ・ ・ ・ ・ ・ Less than 5kg / cm ²

(Contact Resistance) The electric resistance between the substrate electrode and the pad on the FC is measured. The following criteria were used:・ 1.0 Ω or less × ・ 1.0 Ω or more (insulating) Measure the electric resistance between adjacent substrate electrodes.
The following criteria were used: ○ ・ ・ ・ ・ ・ ・ 10 ¹¹ Ω or more × ・ ・ ・ ・ ・ ・ 10 ¹¹ Ω or less

Table 1 Notes Example 1 Example 2 Resin Solution A-1 70.17 A-2 68.44 Photocationic Polymerization Initiator (B) PCI-220 * 1 4.20 4.44 Sensitizer EDMA * 2 4.20 4.44 Curing component (C) YX-4000 * 3 13.87 14.67 Filler silica 7.14 7.56 Leveling agent BYK-354 * 4 0.42 0.45

Note * 1 Trade name: Nippon Kayaku cationic polymerization initiator * 2 2-Ethyl-9,10-dimethoxyanthracene * 3 Trade name: Yuka Shell Epoxy compound * 4 Trade name: Big Chemie leveling agent

Table 2 Evaluation Items Example 1 Example 2 Developability ○ ○ Resolution ○ ○ Sensitivity ○ ○ Adhesion ○ ○ Contact Resistance ○ ○ Insulation ○ ○

[0043]

As is apparent from the results shown in Table 2, the high-energy radiation-sensitive cationically curable sealant of the present invention is excellent in developability, resolution and sensitivity, and the obtained cured product is an adhesive. sex,
Excellent contact resistance and insulation. Further, it has a small curing shrinkage, and is useful for sealing connection of an integrated circuit element such as FC on a printed circuit board, and particularly for sealing connection of FC for CSP.

Claims (11)

[Claims] 1. A high-energy radiation-sensitive cationically curable encapsulation comprising a high-energy radiation-sensitive cationically curable resin (A), a cationic photopolymerization initiator (B) and a curing component (C). Agent. 2. A high-energy radiation-sensitive cation-curable resin (A) comprising an epoxy resin (a) having at least two epoxy groups in a molecule and an alcoholic hydroxyl group-containing monocarboxylic acid compound (b). The high energy ray-sensitive cationically curable sealant according to claim 1, which is a reaction product of a reactant and a polybasic acid anhydride (c). 3. An epoxy resin (a) having at least two epoxy groups in a molecule, which is a reaction product of a bisphenol-type epoxy resin and epihalohydrin and has an epoxy equivalent of 280 to 500 g / equivalent.
A novolak type epoxy resin having an epoxy equivalent of 150 to 250 g / equivalent or an epoxy resin of a condensate of a phenol compound and an aromatic aldehyde compound having an epoxy equivalent of 150 to 250 g / equivalent.
The high-energy radiation-sensitive cation-curable sealant according to claim 2, which is an equivalent amount of an epoxy resin. 4. The high-energy radiation-sensitive cationically curable sealant according to claim 2, wherein the alcoholic hydroxyl group-containing monocarboxylic acid compound (b) is dimethylolpropionic acid or dimethylolbutanoic acid. 5. The method according to claim 2, wherein the addition ratio of the alcoholic hydroxyl group-containing monocarboxylic acid (b) is 10 to 70 equivalent% of the epoxy equivalent of the epoxy resin (a). High-energy radiation-sensitive cation-curing sealant. 6. The polybasic acid anhydride (c) comprises succinic anhydride,
It is one or more polybasic anhydrides selected from phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, trimellitic anhydride, and pyromellitic anhydride. The high-energy radiation-sensitive cation-curable sealant according to any one of claims 2 to 5. 7. The high-energy radiation-sensitive cationically curable resin (A) has an acid value of 50 to 150 mg · KOH / g in solid content.
The high-energy radiation-sensitive cation-curable sealant according to any one of claims 1 to 6, which is in the range described above. 8. A printed circuit board comprising the high-energy radiation-sensitive cation-curable sealant layer according to any one of claims 1 to 7. 9. A method for connecting and sealing an electrode pad formed on an integrated circuit element and an electrode terminal on a printed wiring board formed corresponding to the pad via a metal bump. And a method for connecting and sealing an integrated circuit element to a printed wiring board using a high-energy radiation-sensitive cation-curable sealant. 10. A) a step of forming a metal bump on at least one of an electrode pad and an electrode terminal; and a) a high-energy radiation-sensitive cation-curing sealant is applied to at least one of the integrated circuit element side and the substrate side surface. C) exposing the high-energy radiation-sensitive cation-curable sealant to portions other than the electrode pad portion or the electrode terminal portion with a high-energy radiation; d) irradiating infrared rays or baking in a heating furnace; E) a step of removing unexposed portions using an aqueous alkali solution; f) a step of irradiating a cured film of a high-energy radiation-sensitive cation-curable sealant with high-energy radiation as necessary; g) an electrode pad and an electrode. Face the terminals,
10. An integrated circuit device according to claim 9, wherein the integrated circuit element is provided on a substrate, comprising: bonding an electrode pad or an electrode terminal opposed to the metal bump, followed by thermocompression bonding to connect and seal both electrode surfaces. Connection sealing method. 11. The high-energy radiation-sensitive cation-curable sealant according to claim 1, wherein the high-energy radiation-sensitive cation-curable sealant is a high-energy radiation-sensitive cation-curable sealant according to any one of claims 1 to 7. 3. The method for sealing a connection of an integrated circuit according to item 1.