JP2000248025A - Acrylic resin, adhesive and adhesive film using the same and production of acrylic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain acrylic resins suitably used for adhesives and adhesive films having heat resistance, electric corrosion resistance, moisture resistance required when installing semiconductor chips having large differences in heat expansion coefficients to various high density print circuit boards such as glass epoxy substrates, flexible substrates and the likes and especially little degradation when carrying out a moisture resistance test under a severe condition such as pressure cooker test(PCT) or the like. SOLUTION: This acrylic resin consists of 1-10 wt.% of (A') a structural unit derived from an epoxy group-having (meth)acrylate monomer, 10-50 wt.% of (B) a structural unit originated from acrylonitrile and 40-89 wt.% of (C') a structural unit derived from other copolymerizable monomers containing >=50 wt.% of a methacrylate monomer and has 500,000-1,500,000 weight average molecular weight and (-50) to 0 deg.C glass transition temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acrylic resin suitably used for an adhesive and an adhesive film, an adhesive and an adhesive film using the acrylic resin, and a method for producing the acrylic resin.

[0002]

2. Description of the Related Art In recent years, with the development of electronic devices, the mounting density of electronic components has increased, and bare chip mounting of semiconductors on printed wiring boards, where low cost can be expected, has been promoted.

As a substrate for mounting a semiconductor chip, a ceramic substrate having a relatively small coefficient of thermal expansion in order to ensure connection reliability and a ceramic substrate having a relatively high thermal conductivity in order to easily radiate heat to the outside have been used in many cases. Was. A liquid adhesive represented by a silver paste is used for mounting a semiconductor chip on such a ceramic substrate.

A film adhesive is used for a flexible printed wiring board and the like, and a system mainly containing acrylonitrile butadiene rubber is often used.

[0005] Investigations on printed wiring board-related materials include an acrylic resin, an epoxy resin, a polyisocyanate, and an inorganic filler disclosed in JP-A-60-243180 as an improved solder heat resistance after moisture absorption. There is glue. Also, JP-A-61-13868.
There is an acrylic resin, an epoxy resin, and an adhesive containing a primary amine compound having a urethane bond in the molecule and having both ends terminated with a primary amine compound and an inorganic filler, which are disclosed in Japanese Patent Publication No. However, these deteriorate significantly when a moisture resistance test is performed under severe conditions such as a pressure cooker test (PCT) treatment.

When a silver paste adhesive is used for mounting a semiconductor chip on a ceramic substrate, the dispersion of the silver filler becomes uneven due to the sedimentation of the silver filler, and it is necessary to pay attention to the storage stability of the paste. Is L
There are problems such as inferiority to OC (Lead on Chip) and the like. In addition, as the film-like adhesive, a system containing acrylonitrile-butadiene rubber as a main component has been often used, but when treated at a high temperature for a long time, there are problems such as a large decrease in the adhesive strength and inferior electric corrosion resistance. there were. In particular, when a humidity resistance test is performed under severe conditions such as a PCT process used in reliability evaluation of semiconductor-related components, deterioration is large.

Also, Japanese Patent Application Laid-Open No. 60-243180,
Japanese Patent Application Laid-Open No. 61-138680 also discloses P
Deterioration is large in a moisture resistance test under severe conditions such as CT processing.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide heat resistance required for mounting a semiconductor chip having a large difference in thermal expansion coefficient on various high-density printed wiring boards such as a glass epoxy board and a flexible board. Provided is an acrylic resin having electrical corrosion resistance and moisture resistance, and particularly suitable for use in adhesives and adhesive films which are less likely to deteriorate when subjected to a moisture resistance test under severe conditions such as PCT treatment, and a method for producing the same. It is in.

Another object of the present invention is to provide an adhesive and an adhesive film using the above-mentioned acrylic resin and having excellent properties described above.

[0010]

According to the present invention, there are provided (A ') a structural unit derived from an epoxy group-containing (meth) acrylate monomer in an amount of from 1 to 10% by weight, and (B') acrylonitrile derived structural unit in an amount of from 10 to 50%. % By weight and 40 to 89% by weight of a structural unit derived from another copolymerizable monomer having a content of (C ′) methacrylate monomer of 50% by weight or more and a weight average molecular weight of 500,000 to 1,50.
The present invention provides an acrylic resin having a glass transition temperature of -50 to 0 ° C at 000.

The present invention also provides (A) 1 to 10% by weight of a (meth) acrylate monomer having an epoxy group, (B)
A solution composed of 10 to 50% by weight of acrylonitrile and 40 to 89% by weight of another copolymerizable monomer having a content of (C) methacrylate monomer of 50% by weight or more is solution-polymerized to have a weight average molecular weight of 500,000 to 1%. , 500,
The present invention provides a method for producing an acrylic resin, which comprises obtaining a resin having a glass transition temperature of -50 to 0 ° C.

The present invention also provides an adhesive and an adhesive film comprising the above acrylic resin, epoxy resin and epoxy resin curing agent.

[0013]

DETAILED DESCRIPTION OF THE INVENTION As the (meth) acrylate monomer having an epoxy group used in the present invention, compounds having a copolymerizable double bond such as glycidyl methacrylate and glycidyl acrylate are used.

In order to improve insulation reliability during moisture absorption, a (meth) acrylate monomer having a total of 30 ppm or less of a chlorine ion and a hydrolyzable chloride ion in total having an epoxy group, for example, NOF Corporation Blenmer GS can be preferably used.

The amount of the (meth) acrylate monomer (A) having an epoxy group is 1 to 10% by weight, preferably 3 to 7% by weight, based on the total amount of the components (A), (B) and (C). Used by weight. If it is less than 1% by weight, the required adhesive strength cannot be obtained. If it exceeds 10% by weight, the resin may gel.

The amount of acrylonitrile (B) used is 10 to 10 with respect to the total amount of components (A), (B) and (C).
It is 50% by weight, preferably 20 to 40% by weight. 1
If it is less than 0% by weight, the required elastic modulus cannot be obtained. If it exceeds 50% by weight, the elastic modulus becomes too high.

The copolymerizable monomers contained in (C) other copolymerizable monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylate. Alkyl (meth) acrylate or cycloalkyl (meth) acrylate such as isobutyl, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, 2- (meth) acrylate Hydroxyalkyl (meth) acrylates such as hydroxyethyl and 2-hydroxypropyl (meth) acrylate, (meth)
Aminoalkyl (meth) acrylates such as aminomethyl acrylate, N-methylaminomethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate;
Styrene-based monomers such as methacrylic acid, acrylic acid, styrene, vinyltoluene and α-methylstyrene; vinyl derivatives such as vinyl chloride, vinylidene chloride, vinyl acetate and isopropenyl acetate; and unsaturated dicarboxylic acids such as maleic acid and fumaric acid. There are basic acids, acid anhydrides thereof, monoesters such as monomethyl ester and monoethyl ester, and diesters such as dimethyl ester and diethyl ester.

When a (meth) acrylic acid having a carboxyl group or a hydroxyalkyl (meth) acrylate having a hydroxyl group is used, a crosslinking reaction proceeds, so that the adhesive strength may be reduced.

Further, a copolymerizable monomer having a bromine atom can be used. Examples of the copolymerizable monomer having a bromine atom include brominated styrene (trade name: frame cut 310-K, commercially available from Tosoh Corporation);
Flamecut 122K, a trade name of 2,2-bis (4-allyloxy-3,5-dibromophenyl) propane; Pyrogard FR-100, a trade name of tribromophenylallyl ether commercially available from Daiichi Kogyo Seiyaku; Trade name FR-1025 of pentabromobenzyl acrylate commercially available from East Co., Ltd.
M and other copolymerizable monomers having a bromo group can be used. The number of copolymerizable double bonds is preferably one, and if it is two or more, there is a possibility of gelling, so that the amount used is small and the effect of flame retardancy is reduced. The amount of the copolymerizable monomer having a bromo atom is preferably 10% by weight or more, more preferably 20 to 30% by weight, based on the total amount of the components (A), (B) and (C).

In the present invention, (C) other copolymerizable monomers having a methacrylate monomer content of 50% by weight or more, preferably 60% by weight or more are used. When the ratio of the methacrylate monomer is 5
If it is less than 0% by weight, sufficient moisture resistance cannot be obtained.

Examples of the methacrylate monomer include alkyl methacrylate or cycloalkyl methacrylate such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, and cyclohexyl methacrylate; Examples include hydroxyalkyl methacrylates such as 2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate; aminomethyl methacrylates such as aminomethyl methacrylate; N-methylaminomethyl methacrylate; and N, N-diethylaminoethyl methacrylate. Can be

(C) An acrylate monomer is preferably used as a copolymerizable monomer used together with a methacrylate monomer as another copolymerizable monomer, and acrylate monomers corresponding to the above-mentioned various methacrylate monomers are used.

The method of polymerizing the acrylic resin of the present invention is not particularly limited, but preferably the above-mentioned (A), (B) and (C)
It can be obtained by solution polymerization of a monomer solution comprising the components by a known radical polymerization method or the like. In this case, as an organic solvent, an aromatic solvent such as toluene and xylene, a ketone solvent such as methyl ethyl ketone and methyl isobutyl ketone, an ester solvent such as ethyl acetate and butyl acetate,
Chlorine solvents such as carbon tetrachloride can be used. Further, upon polymerization, benzoyl peroxide, dicumyl peroxide, dibutyl peroxide, organic peroxides such as t-butylperoxybenzoate, azobisisobutyronitrile, azobisvaleronitrile and the like An azobis compound is used.

The monomer concentration at the start of the solution polymerization is preferably 90 to 100% by weight, more preferably 95 to 100% by weight. If the monomer concentration is less than 90% by weight, the molecular weight tends not to be increased. The reaction temperature is preferably from 80 to 90 ° C, more preferably from 82 to 88 ° C. If it is higher than 90 ° C., the molecular weight of the polymer tends to decrease, and if it is lower than 80 ° C., the reaction tends to stop.
The polymerization rate at the time of stopping the reaction is preferably 20 to 40%, more preferably 25 to 35%. If the polymerization rate is low, the yield tends to decrease, and if it is high, the molecular weight dispersity tends to increase. The target degree of dispersion is preferably 2.0-3.0, more preferably 2.
3 to 2.5. The polymerization initiator concentration is (A),
Preferably 0.01 to 0.1 part by weight, preferably 0.02 part by weight, based on 100 parts by weight of the total of components (B) and (C).
０．１0.1 parts by weight. If it exceeds 0.1 part by weight, the molecular weight of the polymer tends to be low, and if it is too small, it does not tend to react.

In the polymer obtained by polymerizing the components (A), (B) and (C), the structural unit derived from the monomer composed of the components (A '), (B') and (C ') is used. The composition is almost the same as the composition of the monomer composed of the components (A), (B) and (C) used in the polymerization.

The weight average molecular weight of the acrylic resin of the present invention needs to be 500,000 or more from the balance of properties. If it is less than 500,000, the strength and flexibility in the form of a sheet or a film are reduced, and the tackiness is increased. The preferred weight average molecular weight is 500,000
~ 1,500,000, more preferably 700,
000 to 1,000,000. The weight average molecular weight was determined by gel permeation chromatography (GP
C) is measured using a standard polystyrene calibration curve.

The acrylic resin of the present invention must have a glass transition temperature of -50 ° C to 0 ° C. If the glass transition temperature is lower than -50 ° C or higher than 0 ° C, it is not preferable from the balance between the elastic modulus and other properties. A preferred glass transition temperature is -50 to -5C, more preferably -40.
~ -10 ° C.

An epoxy resin and an epoxy resin curing agent are blended with the above acrylic resin to obtain an adhesive or an adhesive film of the present invention.

The concentration of chloride ion and hydrolyzable chloride ion in the acrylic resin, adhesive or adhesive film of the present invention is 30 pp in total when measured by ion chromatography.
m or less.

The method for measuring the chloride ion and the hydrolyzable chloride ion of the adhesive film is as follows.
g, add 10 ml of ultrapure water, and add PCT (120 ° C./2 at
m / 20 hours). Take 1 g of this extract and measure the chloride ion concentration by ion chromatography. The ion chromatograph is measured using ICS-A23 manufactured by Yokogawa Analytical Systems Co., Ltd.

The epoxy resin used in the present invention may be any resin as long as it cures and exhibits an adhesive action.
An epoxy resin having two or more functional groups and preferably having a molecular weight of less than 5000 is used. For example, bisphenol A type,
Liquid epoxy resins such as bisphenol F type, and polyfunctional epoxy resins such as phenol novolak type and cresol novolak type can be used, and the trade names of Yuka Shell Epoxy Co., Ltd. Epicoat 807, Epicoat 827, Epicoat 828, Dow Chemical Japan Company product name E. FIG. R. 330, D.I. E. FIG. R. 331; E. FIG.
R. 361, trade name YD128, Y of Toto Kasei Co., Ltd.
DF170, trade name EPPN-20 of Nippon Kayaku Co., Ltd.
1, EOCN1012, EOCN1025, and ESCN-001 and ESCN-195 of Sumitomo Chemical Co., Ltd. can be used.

A phenoxy resin compatible with an epoxy resin can be used. Examples of the phenoxy resin include Phenototo Y, a trade name of Toto Kasei Co., Ltd.
P-40, Phenotote YP-50, Phenotote YP
-60 can be used.

The epoxy resin is preferably blended in an amount of 120 to 250 parts by weight based on 100 parts by weight of the acrylic resin.

Examples of the epoxy resin curing agent used in the present invention include amine, polyamide, acid anhydride, polysulfide, boron trifluoride, and bisphenol A, bisphenol A, which is a compound having two or more phenolic hydroxyl groups in one molecule. F, bisphenol S and the like can be used. In particular, it is preferable to use a phenol novolak resin, a bisphenol novolak resin, a cresol novolak resin, or the like, which is excellent in resistance to electric corrosion when absorbing moisture.
2, phenolite LF2822, phenolite TD-2
090, Phenolite TD-2149, Phenolite V
H4150 and phenolite VH4170 can be used.
Epoxy resin curing agent is 10 to 10 parts by weight of the total amount of acrylic resin, epoxy resin and epoxy resin curing agent.
It is preferable to add 20 parts by weight.

It is preferable to use a curing accelerator together with the epoxy resin curing agent. As the curing accelerator, various imidazole compounds can be used. For example, 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-
Cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, etc. can be used, and the trade name of Shikoku Chemicals Co., Ltd. 2E4M
Z, 2PZ-CN, 2PZ-CNS can be used. The epoxy resin curing accelerator is used in an amount of 0.1 to 100 parts by weight of the total amount of the acrylic resin, the epoxy resin and the epoxy resin curing agent.
It is preferable to add 0.5 parts by weight.

A coupling agent may be added to the adhesive or the adhesive film to improve the bonding at the interface. As the coupling agent, a silane coupling agent is preferable. As a silane coupling agent, for example, γ-
Glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-ureidopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane and the like can be used. . It is preferable to add 0.5 to 3 parts by weight of the coupling agent to 100 parts by weight of the total amount of the acrylic resin, the epoxy resin, and the epoxy resin curing agent.

Further, the handling properties and thermal conductivity of the adhesive and the adhesive film are improved, the flame retardancy is given, the melt viscosity is adjusted,
For the purpose of imparting thixotropic properties and improving surface hardness, an inorganic filler can be added. The amount of the epoxy resin curing agent is from 5 to 100 parts by weight of the total amount of the acrylic resin, the epoxy resin and the epoxy resin curing agent from the viewpoint of the effect.
It is preferable to mix 40 parts by weight.

As inorganic fillers, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, alumina powder, crystalline silica, amorphous silica, aluminum nitride powder, Boron nitride powder, aluminum borate whiskers and the like can be used.

In order to improve the thermal conductivity, alumina,
It is preferable to use aluminum nitride, boron nitride, crystalline silica, amorphous silica, or the like.

In order to impart flame retardancy, aluminum hydroxide, magnesium hydroxide, antimony trioxide, diantimony pentoxide and the like are preferred.

For adjusting the melt viscosity and imparting thixotropic properties, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, alumina powder, crystalline silica, non-crystalline Silica and the like are preferred.

Further, an ion scavenger can be used to prevent adsorption of ionic impurities. As the ion scavenger, for example, a triazine thiol compound or a bisphenol-based reducing agent known as a copper damage inhibitor for preventing copper from being ionized and eluted can be used. It is preferable to add 0.1 to 1 part by weight of the ion scavenger to 100 parts by weight of the total amount of the acrylic resin, the epoxy resin, and the epoxy resin curing agent.

The adhesive film of the present invention comprises the above (A)
A varnish is prepared by dissolving or dispersing each of the components (B) and (C) in a solvent, and the varnish is applied on a base film and heated to remove the solvent, thereby obtaining an adhesive layer. As the base film, for example, a polyimide film such as Kapton (trade name of Toray Industries, Inc. and DuPont Co., Ltd.) or Apical (trade name of Kanebuchi Chemical Industry Co., Ltd.) can be used.
The thickness of the base film is preferably 1 to 800 μm, and the thickness of the adhesive layer is preferably 0.1 to 500 μm.

Solvents for varnishing are methyl ethyl ketone, acetone, methyl isobutyl ketone, which have relatively low boiling points,
Toluene, butyl cellosolve, 2-ethoxyethanol, methanol, ethanol and the like can be used.

In the production of the varnish, it is preferable to disperse the varnish using a grinder, a three-roll mill, a bead mill or the like in consideration of the dispersion of the inorganic filler.

The acrylic resin of the present invention has a low elastic modulus at around room temperature, and the mixture ratio of the acrylic resin in the adhesive and the adhesive film is increased to cause a difference in the thermal expansion coefficient between the semiconductor chip and the printed wiring board. The crack can be suppressed by the effect of relaxing the stress generated in the heating / cooling process at the time of the temperature cycle test. In addition, the acrylic resin of the present invention has excellent reactivity with an epoxy resin, and the cured product of the adhesive is chemically and physically stable.
Excellent performance in a moisture resistance test represented by T treatment. In addition, the use of a high molecular weight acrylic resin solves problems of workability such as a decrease in strength, a decrease in flexibility, and an increase in tackiness of a conventional adhesive film.

Further, the epoxy group contained in the acrylic resin of the present invention partially reacts with the epoxy resin, and the epoxy resin containing the unreacted epoxy group is entirely crosslinked and gelled. Workability is not impaired even when a large number of groups are contained. Further, since a large number of unreacted epoxy resins are present in the gel, even when the whole is gelled, the decrease in the adhesiveness is reduced.

When the adhesive is dried, the epoxy group and the epoxy resin contained in the acrylic resin react together. However, the epoxy resin containing an epoxy group of the present invention has a large molecular weight and the epoxy group is contained in one molecular chain. Even if the reaction proceeds slightly due to the inclusion, it gels. Usually, differential scanning calorimetry (D
SC) of 10-4 of the total curing calorific value as measured using SC).
Gelation occurs in a state where 0% heat generation is completed, that is, in the first half of the A or B stage. Therefore, because it is gelled in a state containing a lot of unreacted components such as epoxy resin,
The melt viscosity is greatly increased as compared with the case where the gel is not gelled, and the workability is not impaired. In addition, the adhesive
Since the film can be formed while containing many unreacted components such as an epoxy resin, there is an advantage that the life (effective use period) of the adhesive film is extended.

In the conventional epoxy resin-based adhesive, gelation occurs for the first time in the C-stage state from the latter half of the B-stage, and the unreacted components at this stage have a small amount of unreacted components. Since less unreacted components ooze out, the adhesiveness decreases. Further, although it is not clear about the reactivity of the epoxy group contained in the acrylic resin and the epoxy group of the epoxy resin, it is sufficient that the epoxy group contained in the acrylic resin has at least the same degree of reactivity, and only the epoxy group contained in the acrylic resin is selectively used. You do not need to react to

The A, B, and C stages in this case are as follows:
The A stage indicates the degree of curing of the adhesive, and the A stage is in a state of almost uncured and not gelled, and a state in which the calorific value of curing using DSC is 0% to 20% of the total curing calorific value. . The B stage is a state in which curing and gelation have progressed slightly, and a state in which the heat generation of curing is 20 to 60% of the total heat generation of curing. The C stage is in a state where the curing has progressed considerably and is in a gel state, and a state in which the heating value of the curing has been 60 to 100% of the total curing heating value.

Regarding the determination of gelation, the adhesive was immersed in a highly permeable solvent such as tetrahydrofuran (THF) and allowed to stand at 25 ° C. for 20 hours, after which the adhesive was swollen without being completely dissolved. Those were judged to be gelled.

[0052]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. In the examples, parts and% indicate parts by weight and% by weight, respectively, unless otherwise specified. [Production Method of Acrylic Resins A to F] The compound (I) shown in Table 1 was placed in a reactor equipped with a mixer and a cooler.
Heat to 85 ° C., add the blend (II) shown in Table 1, keep the temperature for 4 to 8 hours, and obtain a polymer reacted at a conversion of 20 to 30%. After cooling, methanol is added to precipitate the polymer, and the supernatant is removed. The methanol remaining in the polymer is dried, followed by the addition of methyl ethyl ketone to a solids content of 15%.

The weight average molecular weights of the polymers A to F were measured by the following method. [Method for measuring weight average molecular weight] The weight average molecular weight is measured by gel permeation chromatography (GPC) using a calibration curve with standard polystyrene. <GPC conditions> Equipment used: Hitachi 635 type HPLC [manufactured by Hitachi, Ltd.] Column: Gelpack R-440, R450, R400
M [trade name, manufactured by Hitachi Chemical Co., Ltd.] Eluent: tetrahydrofuran Measurement temperature: 40 ° C. Flow rate: 2.0 ml / min Detector: differential refractometer The measurement results are shown in Table 1. The glass transition temperature is
It is a calculated value. (Reference data: An introduction to synthetic resins for paint: written by Kyozo Kitaoka)

[0054]

[Table 1] Examples 1 to 4 and Comparative Examples 3 to 4 The materials (* ¹ to
* ⁶ ) was added to obtain a varnish of the adhesive composition. The obtained varnish was applied on a polyethylene terephthalate film having a thickness of 75 μm, and dried by heating at 140 ° C. for 5 hours to form an 80 μm-thick B-stage coating film to prepare an adhesive film. * ¹ : Bisphenol A type epoxy resin (using Epicoat 828 manufactured by Yuka Shell Epoxy) * ² : Cresol novolak type epoxy resin (using ESCN001 manufactured by Sumitomo Chemical Co., Ltd.) * ³ : Phenol novolak resin (Dainippon Ink) * ⁴ : Phenoxy resin (uses Phenototh YP-50 manufactured by Toto Kasei Co., Ltd.) * ⁵ : 1-cyanoethyl-2-phenylimidazole (Curesol 2PZ- manufactured by Shikoku Chemicals Co., Ltd.) * ⁶ : Acrylonitrile butadiene rubber (using PNR-1 manufactured by Nippon Synthetic Rubber Co., Ltd.) Comparative Example 1 333.0 parts of acrylic resin in Example 1 was changed to phenoxy resin * ⁴ (60 parts of phenoxy resin) The adhesive film was prepared in the same manner as It was.

Comparative Example 2 An adhesive film was produced in the same manner as in Example 1 except that 333.0 parts of the acrylic resin in Example 1 was changed to acrylonitrile butadiene rubber * ⁶ (50 parts).

A semiconductor device manufactured by bonding a semiconductor chip and a wiring board using the obtained adhesive film was examined for heat resistance, electric corrosion resistance and moisture resistance. The storage elastic modulus of the adhesive film was measured using a dynamic viscoelasticity measuring device. The method for evaluating heat resistance is as follows. A semiconductor device sample (a solder ball is formed on one side) in which a semiconductor chip and a flexible printed wiring board using a polyimide film having a thickness of 25 μm as a base material are bonded together with an adhesive film is prepared. And temperature cycling test. The reflow crack resistance was evaluated by passing the sample through an IR reflow furnace set at a temperature such that the maximum temperature of the sample surface was maintained at 240 ° C. for 20 seconds, and then cooling the sample at room temperature twice. The presence or absence was observed. Those with no cracks were evaluated as good, and those with cracks were evaluated as defective. In the temperature cycle test, the process in which the sample was left in an atmosphere of −55 ° C. for 30 minutes and then left in an atmosphere of 125 ° C. for 30 minutes was defined as one cycle, and the number of cycles until breakage occurred was examined. For the evaluation of the corrosion resistance, a sample in which a comb pattern having a line / space of 75/75 μm was formed on an FR-4 substrate, and an adhesive film was further laminated on the comb pattern, was prepared at 85 ° C./85% RH. The insulation resistance value was measured after standing for 1,000 hours under the condition of / DC6V applied. If the insulation resistance value is 10Ω or more, it is considered good.
Those with less than 10Ω were regarded as defective. Evaluation of the moisture resistance was performed by placing a semiconductor device sample in a pressure cooker tester for 9 hours.
After treatment for 6 hours (PCT treatment), peeling and discoloration of the adhesive film were observed. A film without peeling and discoloration of the adhesive film was evaluated as good, and a film with peeling and discoloration was evaluated as poor. The storage elastic modulus was measured by applying a tensile load to the cured adhesive and measuring the temperature from -50 ° C to 300 ° C at a frequency of 10 Hz and a temperature rising rate of 5 to 10 ° C / min in a temperature-dependent measurement mode. The results are shown in Table 2.

[0057]

[Table 2]

[0058]

The acrylic resin, adhesive and adhesive film of the present invention undergo little deterioration when subjected to a corrosion resistance test and a moisture resistance test, especially when subjected to a humidity test under severe conditions such as a PCT treatment. In addition, when a semiconductor chip is mounted on a rigid printed wiring board and a flexible printed wiring board typified by a glass epoxy board or a polyimide board due to a low elastic modulus near room temperature, a difference in thermal expansion coefficient between heating and cooling occurs. Thermal stress can be reduced. Therefore, it is excellent in a temperature cycle test and has excellent heat resistance without cracking during reflow.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoshihiro Nomura 14 Goi South Coast, Ichihara-shi, Chiba F-term (reference) 4G004 AA02 AA10 AA13 AA17 AB05 CA06 CC02 FA05 GA01 4J040 DF051 DF052 DF081 DF082 EC061 EC062 EC071 EC072 GA11 GA13 JA09 KA16 LA01 LA02 LA07 LA08 NA20 QA01 4J100 AB02P AB03P AB04P AC03P AC04P AG02P AG04P AJ02P AJ09P AK31P AK32P AL03P AL04P AL05P AL08P AL09PAL30PAL AL30P AL30P AL09P AL10P AL09P AL10P

Claims (5)

[Claims] (1) 1 to 10% by weight of a structural unit derived from a (meth) acrylate monomer having an epoxy group, and (B ′) a structural unit derived from acrylonitrile.
A weight average molecular weight of 500,000 to 1,500 consisting of 40 to 89% by weight of a structural unit derived from another copolymerizable monomer having a content of (C ') methacrylate monomer of 50% by weight or more and 50% by weight or more. Acrylic resin having a glass transition temperature of −50 to 0 ° C. 2. The acrylic resin according to claim 1, wherein the chlorine ion concentration and the hydrolyzable chloride ion concentration in the acrylic resin are 30 ppm or less in total as measured by ion chromatography. 3. An adhesive comprising the acrylic resin according to claim 1 or 2, an epoxy resin and an epoxy resin curing agent. 4. An adhesive film comprising the acrylic resin according to claim 1 or 2, and an epoxy resin curing agent. 5. Other (A) 1 to 10% by weight of an epoxy group-containing (meth) acrylate monomer, (B) 10 to 50% by weight of acrylonitrile and (C) a content of a methacrylate monomer of 50% by weight or more. A solution having a weight average molecular weight of 500,000 to 1,500,000 and a glass transition temperature of −50 to 0 ° C. is obtained by solution polymerization of a solution comprising 40 to 89% by weight of a copolymerizable monomer. Acrylic resin manufacturing method.