JP2003007927A - Area array terminal surface-mounted package reinforcing underfill sealant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide are array terminal surface mounted package reinforcing underfill sealant which satisfies filling property, hardening property in a low temperature, the heat-resistant cycle property and heat resistance of a cured object with good balance and which is superior in preservation stability at an ordinary temperature. SOLUTION: Underfill sealant is filled in a gap between the area array terminal surface-mounted package of an electronic unit and a substrate, and it reinforces junction between them. Sealant is formed of one liquid epoxy resin component. In the component, (B) amine system latent hardener of 20 to 65 pts.mass and (C) at least one type of reactive diluent of 5 to 60 pts.mass selected from acrylic acid or methacrylic acid ester having oxygen containing saturated heterocyclic residue or polyalkylene oxide residue are mixed with respect to (A) liquid epoxy resin of 100 pts.mass.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention fills a gap (hereinafter referred to as a gap size) between an area array terminal type surface mount package and a substrate of an electronic device, particularly a mobile phone, and firmly fixes the package to the substrate. The present invention relates to an underfill sealant for.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for performance enhancement and miniaturization of portable electronic devices such as PHS, mobile phones, and MP3 players, and semiconductors with large capacity, high speed, and high functionality have been developed, and area array terminal type As a result of the strong demand for miniaturization of surface mount packages, ball grid array (BG
A) and chip size packages (CSP) are drawing attention. These are the traditional quads
This is not a connection method of arranging contact pins along each side of the lead frame like a flat package (QFP) but a method of arranging a large number of solder balls on the bottom surface of the package for connection. It is designed to be smaller and have more pins.

However, in BGA and CSP, the contact area between the surface mount package or substrate of the area array terminal type and the solder balls interposed between them is small, so that contact failure due to mechanical load or thermal load. Prone to

In particular, in portable electronic devices such as PHS, mobile phones, and MP3 players, the chances of receiving a mechanical load due to troubles such as drops and impacts caused by carrying increase, and it is not possible with conventional stationary electronic devices. There has been a serious problem of causing poor contact that was not observed.

Therefore, a method of filling an underfill material in the gap between the area array terminal type surface mount package and the substrate so as to prevent contact failure even when subjected to a mechanical load or a thermal load has been studied. However, BGA and CSP
In general CSP, the gap size between the surface mount package of area array terminal type and the substrate is 200
The gap size is about μm or less, and this gap size tends to become smaller with the demand for miniaturization of electronic devices.

By the way, when the gap size is reduced, it is necessary to reduce the viscosity of the underfill material in order to smoothly fill the underfill material therein. And, as a method of lowering the viscosity of the underfill material, a method of blending an epoxy resin-based reactive diluent has been known so far, but an underfill material blended with an epoxy resin-based reactive diluent is Although the filling property in the gap between the area array terminal type surface mount package and the substrate is improved, other properties required for the underfill material, such as curability at low temperature and heat cycle resistance of the cured product, etc. Is inevitable.

On the other hand, when the space between the area array terminal type surface mount package and the board is filled and fixed to each other, if the arrangement is displaced and it becomes necessary to remove the mount package from the board once, it is easy to remove the package. As an underfill material devised to achieve the above, a thermosetting resin composition in which a curing agent of 3 to 60 parts by mass and a plasticizer of 1 to 90 parts by mass are mixed with 100 parts by mass of an epoxy resin has been proposed ( (Japanese Patent Laid-Open No. 10-204259), the purpose of this is to facilitate the removal, so that a small gap size between the area array terminal type surface mount package and the substrate is filled to firmly fix the two. Was unsuitable for use as an underfill material for.

As described above, in the past, it has been applied to the portable electronic equipment such as the filling property in the gap between the surface mount package of the area array terminal type and the substrate, the curability at low temperature, the heat cycle resistance and the heat resistance of the cured product. There is no known underfill material that satisfies all the properties required for the underfill material used in a well-balanced manner. Therefore, there has been a demand for the development of an area array terminal type one-pack type epoxy resin composition for surface mount package reinforcement, which is used in portable electronic devices satisfying these required characteristics in a well-balanced manner.

[0009]

Under these circumstances, the present invention is well-balanced in filling property, curability at low temperature, heat cycle resistance and heat resistance of the cured product, and further, The purpose of the present invention is to provide an underfill encapsulant for reinforcing an area array terminal type surface mount package which is excellent in storage stability at room temperature.

[0010]

DISCLOSURE OF THE INVENTION The present inventors have overcome various drawbacks of conventional underfill encapsulants for reinforcing surface mount packages, and are required to have proper properties such as curability at low temperature. As a result of repeated studies on improving the filling property into the gap while maintaining the heat cycle resistance of the cured product, a mixture of a liquid epoxy resin and an amine-based latent curing agent was treated with a specific acrylic acid or It was found that the object can be achieved by diluting with a reactive diluent selected from methacrylic acid esters, and the present invention has been completed based on this finding.

That is, the present invention provides an underfill encapsulant for filling a space between an area array terminal type surface mount package of an electronic device and a substrate to reinforce the joint between the two, which is (A) liquid. From acrylic acid or methacrylic acid ester having (B) 20 to 65 parts by mass of amine-based latent curing agent and (C) oxygen-containing saturated heterocyclic residue or polyalkylene oxide residue, relative to 100 parts by mass of epoxy resin. An underfill encapsulant comprising a one-pack type epoxy resin composition containing 5 to 60 parts by mass of at least one reactive diluent selected.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The liquid epoxy resin as the component (A) used in the present invention can be arbitrarily selected from epoxy resins which are liquid at room temperature or working temperature. Examples of such epoxy resin include bisphenol A type epoxy resin, bisphenol AD type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, hydrogenated bisphenol A type epoxy resin, cycloaliphatic epoxy resin, naphthalene. Examples thereof include ring-containing epoxy resins and glycidyl ethers of organic carboxylic acids. In the present invention, these may be used alone or in combination of two or more. Further, as long as the composition retains a liquid state, a solid epoxy resin at room temperature can be appropriately added. In particular,
In order to keep the viscosity of the composition low, an epoxy resin having a viscosity at 25 ° C. of 15 Pa · s or less is preferable, and 10
Pa. Those of s or less are optimal. Among these, the mass ratio of bisphenol A type epoxy resin and bisphenol F type epoxy resin having low viscosity and low crystallinity is 40:60.
Mixtures in the range of 60 to 40 or bisphenol F type epoxy resin with low crystallinity are most suitable.

Next, as the amine-based latent curing agent as the component (B), any of the latent curing agents usually used in conventional one-component epoxy resin compositions can be selected and used. . Among these, a solid dispersion type latent curing agent that is a solid insoluble in the epoxy resin at room temperature but dissolves by heating and functions as a curing agent is particularly preferable.
Examples thereof include imidazole compounds which are solid at room temperature, dicyandiamide and its derivatives, amine-epoxy adduct compounds, amine-urea adduct compounds, neutralization of acidic or basic compounds, and neutral salts. A single compound or a combination of two or more compounds can be mentioned. Of these, amine-epoxy adduct compounds or amine-urea adduct compounds are particularly preferable from the viewpoint of the balance between storage stability and curability at low temperatures. This amine-epoxy adduct compound is formed by addition reaction of an amine compound with an epoxy compound.

Examples of the epoxy compound include polyglycidyl ether obtained by reacting a polyhydric phenol such as bisphenol A, bisphenol F, catechol and resorcinol or a polyhydric alcohol such as glycerin and polyethylene glycol with epichlorohydrin, p. -Hydroxybenzoic acid, β-hydroxynaphthoic acid and other polycarboxylic acids such as glycidyl ether ester, phthalic acid and terephthalic acid obtained by reacting with epichlorohydrin Glycidylamine compound obtained by reacting glycidyl ester, 4,4'-diaminodiphenylmethane, m-aminophenol, etc. with epichlorohydrin, epoxidized phenol novolac Resins, epoxidized cresol novolac resins, multifunctional epoxy compounds and butyl glycidyl ether, such as epoxidized polyolefins, phenyl glycidyl ether, and the like monofunctional Epokin compounds such as glycidyl methacrylate.

Examples of the amine compound include aliphatic amines such as diethylenetriamine, triethylenetetramine, n-propylamine, 2-hydroxyethylaminopropylamine, cyclohexylamine and 4,4-diaminodicyclohexylmethane. , 4'-
Aromatic amine compounds such as diaminodiphenylmethane, 2-methylaniline, 2-ethyl-4-methylimidazole, 2-ethyl-4-methylimidazoline, 2,4-
Nitrogen-containing heterocyclic compounds such as dimethylimidazoline, piperidine, piperazine, dimethylaminopropylamine,
Amine compounds such as diethylaminopropylamine, di-n-propylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, N-methylpiperazine and 2-
Primary or secondary amines having a tertiary amino group in the molecule, such as imidazole compounds such as methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, and 2-phenylimidazole,
2-dimethylaminoethanol, 1-methyl-2-dimethylaminoethanol, 1-phenoxymethyl-2-dimethylaminoethanol, 2-diethylaminoethanol, 1-butoxymethyl-2-dimethylaminoethanol, 1- (2-hydroxy- 3-phenoxypropyl)
-2-Methylimidazole, 1- (2-hydroxy-3
-Phenoxypropyl) -2-ethyl-4-methylimidazole, 1- (2-hydroxy-3-butoxypropyl) -2-methylimidazole, 1- (2-hydroxy-3-butoxypropyl) -2-ethyl-4 -Methylimidazole, 1- (2-hydroxy-3-phenoxypropyl) -2-phenylimidazoline, 1- (2-hydroxy-3-butoxypropyl) -2-methylimidazoline, 2- (dimethylaminomethyl) phenol, 2 ，
4,6-tris (dimethylaminomethyl) phenol,
N-β-hydroxyethylmorpholine, 2-dimethylaminoethanethiol, 2-mercaptopyridine, 2-benzimidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 4-mercaptopyridine, N, N-dimethylaminobenzoic acid , N, N-
Dimethylglycine, nicotinic acid, isonicotinic acid, picolinic acid, N, N-dimethylglycine hydrazide, N, N
-Alcohols having a tertiary amino group in the molecule, such as dimethylpropionic acid hydrazide, nicotinic acid hydrazide, isonicotinic acid hydrazide, etc., phenols, thiols, carboxylic acids and hydrazides.

Further, active hydrogen compounds having two or more active hydrogens in the molecule during the addition reaction, for example, bisphenol A, bisphenol F, bisphenol S, hydroquinone, catechol, resorcinol, pyrogallol,
Polyhydric phenols such as phenol novolac resin, polyhydric alcohols such as trimethylolpropane, polyhydric carboxylic acids such as adipic acid and phthalic acid, 1,2-dimethylcaptoethane, 2-mercaptoethanol, 1-mercapto-3 -Phenoxy-2-propanol, mercaptoacetic acid, anthranilic acid, lactic acid and the like can be used together. This is advantageous because the storage stability of the obtained epoxy resin can be improved.

Some of these amine-epoxy adduct compounds are described, for example, in Amicure PN-23,
Amicure MY-24, Amicure AH-203 (all manufactured by Ajinomoto Co., Inc.), Hardener X-3361S, Hardner X-3670S (all manufactured by Asahi Denka Kogyo Co., Ltd.), Novacure H
It is commercially available under trade names such as X-3721 and Novacure HX-3741 (all manufactured by Asahi Kasei Corporation). Among these, Novacure HX-3721 or Amicure PN-23, which is excellent in both storage stability and curability at low temperature, is most suitable.

Next, the amine-urea adduct compound is
A compound obtained by the reaction of an amine compound and an isocyanate compound, and as the amine compound in this case, those exemplified as the amine compound of the amine-epoxy adduct compound are used. Examples of the isocyanate compound include monofunctional isocyanate compounds such as n-butyl isocyanate, isopropyl isocyanate, phenyl isocyanate and benzyl isocyanate, hexamethylene diisocyanate, toluylene diisocyanate, 1,5-naphthalene diisocyanate, diphenylmethane-4,4- Diisocyanate, isophorone diisocyanate, xylene diisocyanate, paraphenylene diisocyanate, 1,3,6
-A polyfunctional isocyanate compound such as hexamethylene triisocyanate, and a terminal isocyanate group-containing compound obtained by the reaction of these polyfunctional isocyanate compounds with an active hydrogen compound.

Examples of such a terminal isocyanate group-containing compound include an addition compound having a terminal isocyanate group obtained by the reaction of toluidine isocyanate and trimethylolpropane, and a terminal isocyanate obtained by the reaction of toluylene diisocyanate and pentaerythritol. Examples thereof include isocyanate compounds such as addition compounds having a group, or reaction products with urea compounds such as urea and thiourea. Some of these amine-urea adduct compounds are commercially available, for example, under the trade names of Fujicure FXE-1000 and Fujicure FXB-.
It is marketed under the trade name such as 1050 (all manufactured by Fuji Kasei Co., Ltd.). Among these, Fujicure FXB-1000, which is particularly excellent in both storage stability and curability at low temperature, is most suitable.

In the area array terminal type surface mount package reinforcing underfill sealant of the present invention, (A)
20 to 65 parts by mass, preferably 30 to 60 parts by mass of the amine-based latent curing agent as the component (B) is mixed with 100 parts by mass of the liquid epoxy resin as the component. If the blending amount is less than 20 parts by mass, the curing speed at a low temperature is low and the adhesive strength with the substrate cannot be obtained. If the blending amount is more than 65 parts by mass, the viscosity of the underfill sealant becomes high and the area array The penetration speed into the gap between the terminal type surface mount package and the substrate becomes slow, and sufficient filling properties cannot be obtained.

Next, in the present invention, as a reactive diluent for dissolving the components (A) and (B),
(C) It is necessary to use at least one selected from acrylic acid or methacrylic acid ester having an oxygen-containing saturated heterocyclic residue or a polyalkylene oxide residue. The oxygen-containing saturated heterocyclic residue means a residue of a heterocycle containing an oxygen atom as a heteroatom, in which all the bonds constituting the ring are saturated with hydrogen atoms. The oxygen-containing saturated heterocycle may contain a heteroatom such as a nitrogen atom or a sulfur atom in addition to the oxygen atom. Examples of such an oxygen-containing saturated heterocyclic residue include a morpholino group, a tetrahydrofurfuryl group, a tetrahydropyranyl group and the like.

On the other hand, the polyalkylene oxide residue means
One formed by addition polymerization of a single alkylene oxide such as a polyoxyethylene group or polyoxypropylene group, and addition polymerization of two or more alkylene oxides such as a polyoxyethylene-oxypropylene group Means formed. In this case, the degree of polymerization is preferably in the range of 2-10, especially 3-7.

Examples of the ester of acrylic acid or methacrylic acid used as the component (C) include, for example, morpholinyl acrylate, tetrahydrofurfuryl acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, ethylene oxide-modified dicyclopentenyl acrylate, phenoxy polyethylene. Monofunctional acrylates such as glycol acrylate, ethylene oxide modified methylphenol acrylate, ethylene oxide modified phenoxyphosphoric acid acrylate, ethylene oxide modified bisphenol A diacrylate, diethylene glycol diacrylate, ethylene oxide modified trimethylolpropane triacrylate, propylene oxide modified trimethylolpropane triacrylate, etc. Multi-functional accretion And the like corresponding methacrylates. These acrylates or methacrylates can be used alone or in combination of two or more. Some of these acrylates or methacrylates are commercially available under trade names such as A-MO, A-TMPT-3EO (all manufactured by Shin-Nakamura Chemical Co., Ltd.), and light ester THF (manufactured by Kyoei Chemical Co., Ltd.).

As this reactive diluent, hydroxyethyl acrylate or methacrylate conventionally used in the case of conventional underfill sealants, and esters having a hydroxyl group such as an ester of an epoxy compound and acrylic acid or methacrylic acid are used. If used, the storage stability at room temperature is lowered, and therefore it cannot be used in the present invention.

The component (C) is most preferably ethylene oxide-modified trimethylolpropane triacrylate or morpholinyl acrylate and the corresponding methacrylate, which have low viscosity, storage stability, curability at low temperature, and good adhesiveness. .

This reactive diluent is used in an amount of usually 5 to 60 parts by mass, preferably 5 to 45 parts by mass, per 100 parts by mass of the component (A) liquid epoxy resin. When the amount is less than 5 parts by mass, the effect of lowering the viscosity of the composition cannot be obtained, and when the amount is more than 60 parts by mass, the adhesive force to the substrate decreases.

The area array terminal type surface mount package reinforcing underfill sealant of the present invention has a viscosity of 10 Pa.s at a working temperature, for example, 25.degree. s or less, preferably 7 Pa · s or less. If the viscosity is higher than this, smooth filling in the gap between the area array terminal type surface mount package and the substrate cannot be performed. The underfill encapsulant preferably has an adhesive strength to the substrate after heating of 80 N or higher and a glass transition temperature of 70 ° C. or higher. This bond strength is 8
If it is less than 0 N, sufficient adhesiveness cannot be obtained, and if it is higher than this, it will not sufficiently penetrate into the gap between the substrate and the surface mount package.

The area array terminal type surface mount package reinforcing underfill sealant of the present invention is (A),
It can be prepared by uniformly mixing the components (B) and (C) with a planetary mixer or the like.

The area array terminal type surface mount package reinforcing underfill sealant of the present invention includes:
In addition to the components (A), (B) and (C), an underfill sealant such as a surfactant, a colorant, a stress relaxation agent, a defoaming agent, a leveling agent, a silane coupling agent, etc., if desired. Additives conventionally used in can be added.
These additives may be mixed together with the components (A), (B) and (C), or these additives may be added after mixing the components (A), (B) and (C). May be mixed homogeneously, or (A), (B) and (C) may be mixed with one or two components (A), (B) and (C) before mixing. May be. In this way, a one-pack type epoxy resin compound is obtained, which has a glass transition temperature of 70.
It is preferable that the temperature is not lower than 0 ° C. The underfill encapsulant of the present invention is, for example, filled in a gap between a glass epoxy substrate and a surface mount package and then cured at a low temperature of 75 to 85 ° C. for 55 to 65 minutes, and has an adhesive strength to the glass epoxy substrate. Gives a cured product of 80 N or more.

[0030]

The area array terminal type surface mount package reinforcing underfill encapsulant of the present invention is capable of filling the gap between the area array terminal type surface mount package and the substrate, curability at low temperature, and curing. It has a well-balanced heat cycle resistance and heat resistance, and also has excellent storage stability at room temperature, and is subject to mechanical and thermal loads compared to stationary electronic devices. Even in mobile electronic devices, which are often used, it is possible to dramatically improve the operational reliability of the mobile electronic devices without causing a bonding failure between the area array terminal type surface mount package such as BGA and CSP and the substrate.

[0031]

EXAMPLES Next, the present invention will be described in more detail by way of examples. The viscosity, glass transition temperature, adhesive strength, storage stability and heat cycle resistance shown below are measured as follows.

(1) Viscosity: Using a rotational viscometer (EHD type rotational viscometer manufactured by Tokimec Co., Ltd. (cone diameter: 28 mm, cone angle: 3 °)), the viscosity (Pa. s) was measured and judged according to the following evaluation criteria. ○ (Filling speed into the gap is fast and there is no problem in use):
10 Pa. s or less Δ (filling speed into the gap is slightly slow, but there are few problems in use): 11 to 20 Pa · s × (filling speed into the gap is slow and there is a problem in use):
21 Pa · s or more

(2) Glass transition temperature: The cured product cured under the curing conditions of 80 ° C. and 60 minutes was heated from room temperature to 200 ° C. by a compression method using TMA (TMA-4000 manufactured by Mac Science Co., Ltd.). Speed 5 ℃ / min, load on sample 1
The glass transition temperature was measured under the condition of 0 g and judged according to the following evaluation criteria. ○ (excellent in curability at low temperature and heat resistance of cured product, no problem in use): 70 ° C or higher △ (heat resistance of cured product is poor and some problems in use): 50 ° C or higher 70 Less than ℃ × (heat resistance of the cured product is very poor, there is a problem in use): less than 50 ℃

(3) Adhesive strength; bottom diameter 2 mm, height 2 m
A frustoconical sample cured product with m and a side slope of 5 ° was formed on a FR-4 glass epoxy substrate at 80 ° C. for 60 minutes, and the horizontal force (N) required to peel it off was pushed. It was measured with a gauge and judged according to the following evaluation criteria. ○ (strong adhesion to the board and parts, no problems in use): 80N or more △ (particularly weak adhesion to parts, problems in use): 60N or more and less than 80N × (boards and parts Adhesive strength with is very weak, there is a problem in use): less than 60N

(4) Storage stability: The viscosity of the sample after storage at 25 ° C. for 24 hours and the viscosity of the sample before storage were measured, and the change rate of the viscosity of the sample after storage with respect to the viscosity of the sample before storage ( %) And evaluated according to the following criteria. ○ (Good storage stability, no problem in use at room temperature): Change rate of 0% or more and less than 30% △ (Insufficient storage stability, not suitable for all-day use at room temperature ): Change rate of 30% or more and 60% or less x (poor storage stability and problems in use at room temperature):
Change rate is over 60%

(5) Heat cycle resistance: 105 mm ×
100 μm thickness with a 25 mm × 25 mm opening provided on a 60 mm × 0.8 mm FR-4 glass epoxy substrate.
m polyester film is placed, 0.2 g of the sample is applied to the opening in a cross shape, and 20 mm x 2
A 0 mm x 0.55 mm cover glass is pressed around the cover glass until the sample protrudes, and the sample is heat-cured (curing condition: 80 ° C, 60 minutes) in that state, and the polyester film removed is then heated. It was subjected to a cycle test and evaluated according to the following criteria. Heat cycle tester: TSE-125C manufactured by Tabae Co., Ltd. Heat cycle condition: -40 ° C, 30 minutes → 125 ° C, 3
The 0 minute cooling / heating cycle is defined as one cycle, and this cycle is repeated. Good (heat cycle resistance is good and there is no problem in use): No crack is generated in the cured product of the sample even after 250 cycles, and the cover glass is not peeled off. B (Insufficient heat cycle resistance and problems in use): Cracks of the cured product of the sample or peeling of the cover glass are observed after more than 10 cycles and less than 250 cycles. X (poor heat cycle resistance and problems in use): Cracks of the cured sample or peeling of the cover glass are observed after 10 cycles.

Examples 1 to 7 and Comparative Examples 1 to 9 (A) liquid epoxy resin, (B) amine-based latent curing agent and (C) acrylate-based reactive diluent shown in Table 1 were used.
Using an L planetary mixer (manufactured by Inoue Seisakusho), 25
The mixture was mixed under reduced pressure of 10 mmHg for 1 hour to prepare an area array terminal type surface mount package reinforcing underfill encapsulant. Next, these area array terminal type surface mount package reinforcing underfill sealants were measured for viscosity, glass transition temperature, adhesive strength, storage stability and heat cycle resistance. The results are shown in Table 1.

In each example, the component (A),
The following compounds were used as the component (B) and the component (C). (A) -1: Equivalent mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin (manufactured by Tohto Kasei Co., Ltd., trade name "Epototo ZX-1059", epoxy equivalent 165) (B) -1: microcapsule type Amine-based latent curing agent (manufactured by Asahi Chemical Industry Co., Ltd., trade name "Nova Cure HX-372"
1 ") (B) -2: Amine-epoxy adduct-based latent curing agent (manufactured by Ajinomoto Co., Inc., trade name" Amicure PN-23 ") (C) -1: Ethylene oxide modified trimethylolpropane triacrylate (Shin Nakamura Chemical Co., Ltd.) Made, product name "A-
TMPT-3EO "(C) -2: morpholinyl acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name" A-MO ") (C) -3: 2-hydroxyethyl methacrylate (manufactured by Mitsubishi Rayon Co., Ltd., trade name" acrylic " Ester HO ") (C) -4: Alkyl monoglycidyl ether (manufactured by Japan Epoxy Co., trade name" YED-111E ") (C) -5: Necadecanoic acid monoglycidyl ester (manufactured by Tohto Kasei Co., Ltd., trade name" Neotote E ))

[0039]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 23/31 (72) Inventor Rihei Nagase 4-11-2 Ginza, Chuo-ku, Tokyo Somer Co., Ltd. F-term (reference) 4J002 BG012 BG022 BG072 CD011 CD041 CD051 CD061 CD131 EN016 EN046 EN066 EN076 EQ026 EU076 EU116 EU136 EV026 FD146 FD202 GQ01 GQ05 4J036 AA01 AD01 AD08 AD02 AD08 AD25 AD08 DC02 DC06 DC18 DC02 DC02 DC06 DC10 DC18 DC02 DC06 DC18 DC02 DC06 DC10 DC18 DC02 DC06 DC10 DC01 DC01 DC02 DC06 DC10 DC18 DC02 DC06 DC10 DC18 DC02 DC06 DC10 DC18 DC02 DC06 DC10 DC01 DC02 DC06 DC10 DC18 DC02 DC06 DC10 DC01 DC02 DC06 DC18 DC02 DC06 DC18 DC02 DC06 DC10 DC18 DC02 DC06 DC10 DC01 DC02 DC06 DC18 DC02 DC06 DC18 DC02 DC06 DC10 DC01 DC02 DC06 DC02 DC06 DC18 DC02 DC06 DC18 DC02 DC06 DC10 DC01 DC02 DC06 DC10 DC01 DC02 5F061 BA04 CA04

Claims (3)

[Claims] 1. An underfill encapsulant for filling a gap between a surface mount package of an area array terminal type of an electronic device and a substrate to reinforce the bonding between the two, wherein (A) 100 mass of liquid epoxy resin. To 20 parts by weight of (B) an amine-based latent curing agent and (C) an acrylic acid or methacrylic acid ester having an oxygen-containing saturated heterocyclic residue or a polyalkylene oxide residue. An underfill encapsulant comprising a one-pack type epoxy resin composition containing 5 to 60 parts by mass of one reactive diluent. 2. The (B) amine-based latent curing agent is an amine-
The underfill sealant according to claim 1, which is selected from an epoxy adduct compound and an amine-urea adduct compound. 3. The viscosity at the working temperature is 10 Pa · s or less, the adhesive strength to the substrate after heat curing is 80 N or more, and the glass transition temperature is 70 ° C. or more.
Alternatively, the underfill sealant according to item 2.