WO2011118664A1 - Liquid adhesive for electronic parts and adhesive tape - Google Patents

Abstract

A liquid adhesive for electronic parts which consists of an organic solvent solution containing (a) an acrylonitrile/ butadiene copolymer, (b) a phenol resin, and (c) a component consisting of compounds that each contain two or more maleimido groups, characterized in that the component (c) contains both a compound represented by general formula (1) and a compound represented by general formula (2).

Description

Liquid adhesive and adhesive tape for electronic parts

The present invention relates to a liquid adhesive for an electronic component and an adhesive tape for use in bonding between members around a lead frame constituting a semiconductor device, for example, a lead pin, a semiconductor chip mounting substrate, a heat sink, and a semiconductor chip itself. .
This application claims priority on March 25, 2010 based on Japanese Patent Application No. 2010-069063 filed in Japan, the contents of which are incorporated herein by reference.

Conventionally, as an adhesive tape used in a resin-sealed semiconductor device, there are a lead frame fixing tape, a TAB tape, and the like.
For example, an adhesive tape for fixing a lead frame is used as one that contributes to an improvement in production yield and productivity of the lead frame itself and the entire semiconductor assembly process by fixing lead pins of the lead frame.
This fixing adhesive tape is usually taped onto a lead frame by a lead frame maker and then shipped to a semiconductor maker. After the IC is mounted by the semiconductor maker, the resin is sealed.
For this reason, the adhesive tape for fixing the lead frame has not only general reliability at the semiconductor level and workability during taping, but also sufficient room temperature adhesive force immediately after taping and sufficient resistance to heating in the semiconductor device assembly process. Heat resistance is required.

Conventionally, as an adhesive tape used for such applications, for example, a synthetic rubber-based resin such as polyacrylonitrile, polyacrylic acid ester or acrylonitrile-butadiene copolymer alone on a support film such as a polyimide film, Or what modified | denatured with other resin, or the thing which apply | coated the adhesive mixed with other resin and was made into the B-stage state is used.
In recent years, resin-encapsulated semiconductor devices (semiconductor packages) having a structure as shown in FIGS. 1 to 3 have been developed or manufactured.
In the resin-encapsulated semiconductor device of FIG. 1, the lead pin 3 and the plane 2 are connected by the adhesive layer 6, the semiconductor chip 1 is mounted on the plane 2, and the bonding wire 4 between the semiconductor chip 1 and the lead pin 3. And a structure sealed with a resin 5.
2 has a structure in which the lead pin 3 and the semiconductor chip 1 are fixed by an adhesive layer 6 and sealed together with a bonding wire 4 by a resin 5.
In the apparatus of FIG. 3, the semiconductor chip 1 is mounted on the die pad 7, the electrode 8 is fixed by the adhesive layer 6, and between the semiconductor chip 1 and the electrode 8 and between the electrode 8 and the lead pin 3. Are connected by a bonding wire 4 and sealed with a resin 5.

As an adhesive layer in the resin-encapsulated semiconductor device having the structure shown in FIGS. 1 to 3, an adhesive that can be bonded and cured at a relatively low temperature and has sufficient heat resistance and reliability is known (for example, , See Patent Document 1).
Note that reliability means that current leakage and short-circuit do not occur even under the conditions of a migration test (PCBT: Pressure Cooker Biased Test) described later.
However, it has been required to further improve the migration resistance for such an adhesive.
Migration resistance means that there is no dendrite growth in the migration test without causing a short circuit.

JP 09-176593 A

The present invention has been made in view of the problems as described above, and its intended treatment is that it can be bonded and cured at a low temperature, has sufficient heat resistance and reliability, and migration resistance. It is an object to provide a liquid adhesive and an adhesive tape for electronic parts that are excellent in performance.

The present invention has solved the above problems by the following technical configuration.
(1) A liquid adhesive in which a component (a) an acrylonitrile-butadiene copolymer, a component (b) a phenol resin, and a component (c) a compound containing two or more maleimide groups are dissolved in an organic solvent. The component (c) contains a compound represented by the formula (1) and a compound represented by (2), which will be described later, and a liquid adhesive for electronic parts.
(2) The liquid adhesive for electronic parts as described in (1) above, wherein the component (a) has a Mooney viscosity of 50 to 90M _{1 + 4 at} 100 ° C. and an acrylonitrile content of 5 to 50% by mass. .
(3) The liquid adhesive for electronic parts as described in (1) above, wherein the component (a) is an acrylonitrile-butadiene copolymer having a carboxyl group.
(4) The liquid adhesive for electronic parts as described in (1) above, wherein the component (b) is a phenol resin containing a resol type alkylphenol.
(5) The liquid adhesive for electronic parts as set forth in (1), wherein the component (b) uses a resol type phenol and a novolac type phenol in combination.
(6) The component (c) is used for electronic parts as described in (1) above, wherein the mass ratio of the compounds represented by the formulas (1) and (2) is from 3: 3 to 3:45 Liquid adhesive.
(7) The sum of component (b) and component (c) is 10 to 900 parts by weight with respect to 100 parts by weight of component (a), and occupies the total of component (b) and component (c) The liquid adhesive for electronic parts as described in (1) above, wherein the mass proportion of the component (b) is 10 to 90 mass%.
(8) The liquid adhesive for electronic parts as described in (1) above, further comprising a component (d) a diamine compound.
(9) The liquid adhesive for electronic parts as set forth in (8), wherein the component (d) is a compound represented by the formula (3) described later.
(10) The electronic component according to (8), wherein the component (d) is a compound represented by the formula (4) described later, and has a weight average molecular weight of 200 to 7,000 Liquid adhesive.
(11) The liquid adhesive for electronic parts as described in (1) above, wherein a filler having a particle size of 1 μm or less is contained in an amount of 4 to 40% by mass of the total solid content.
(12) An adhesive tape comprising an adhesive layer formed by applying and drying the liquid adhesive for electronic components according to (1) above on at least one surface of a heat resistant film.
(13) The adhesive tape according to (12), wherein the heat resistant film is a polyimide film.
(14) An adhesive tape comprising an adhesive layer formed by applying and drying the liquid adhesive for electronic parts according to (1) above on at least one surface of a peelable film.

ADVANTAGE OF THE INVENTION According to this invention, the liquid adhesive for electronic components and adhesive tape which can be adhere | attached and hardened at low temperature, have sufficient heat resistance and reliability, and are excellent in migration resistance can be provided.
That is, the liquid adhesive for electronic parts of the present invention can be bonded or cured at a low temperature, has sufficient heat resistance and reliability, and is excellent in migration resistance. Adhesive tape, for example, as lead frame fixing tape, TAB tape, etc., suitable for bonding between members around the lead frame constituting the semiconductor device, for example, lead pins, semiconductor chip mounting substrate, heat sink, semiconductor chip itself, etc. Can be used for

Sectional drawing of an example of the resin-sealed semiconductor device (semiconductor package) using this invention or the conventional adhesive tape Sectional drawing of another example of the resin-sealed semiconductor device using the present invention or the conventional adhesive tape Sectional drawing of further another example of the resin sealing type semiconductor device using this invention or the conventional adhesive tape

Hereinafter, the present invention will be described in detail.
First, the preferable example of the liquid adhesive for electronic components is demonstrated. However, the present invention is not limited to these examples.
The liquid adhesive for electronic parts of the present invention comprises a compound containing at least two components (a) acrylonitrile-butadiene copolymer, component (b) phenol resin, and component (c) maleimide group in an organic solvent. It is a dissolved liquid adhesive, and the component (c) is characterized by using a compound represented by the following formulas (1) and (2) in combination.

Each component will be described below.
Component (a):
As the acrylonitrile-butadiene copolymer as component (a), any known acrylonitrile-butadiene copolymer can be used, but an acrylonitrile-butadiene copolymer having a carboxyl group is preferred.
The reason is that the melt viscosity at the time of heating is increased, the thermal stability is improved, the compatibility with other resins is increased, the insulating properties are stabilized, and the tensile strength of the resin is increased.
The carboxyl group equivalent in the acrylonitrile-butadiene copolymer having a carboxyl group is preferably 1000 to 20000.
The carboxyl group equivalent is a value calculated from the number average molecular weight.
A Mooney viscosity of 50 to 90 M _{1 + 4} (100 ° C.) is preferred.
The reason is that when the Mooney viscosity is within the above range, the thermal stability is improved and the heat resistance is improved.
Moreover, when it uses as an adhesive agent by the improvement of solvent solubility and a fall of melt viscosity, since workability | operativity and adhesiveness become favorable, it is preferable.
When the Mooney viscosity is below the lower limit of the above range, the heat resistance of the resin is lowered and the heat resistance necessary for the semiconductor assembly process cannot be obtained. Further, the melt viscosity at the B stage of the adhesive is lowered, and the flow of the adhesive is increased at the time of processing to the lead frame, which is not preferable. On the other hand, when the Mooney viscosity exceeds the upper limit of the above range, the adhesive is difficult to melt, the fluidity is lowered, and the taping property to the lead frame is lowered. Moreover, since the solubility to a solvent falls and the workability | operativity of adhesive preparation falls, it is not preferable.
Next, the acrylonitrile content of the copolymer is preferably 5 to 50% by mass, and more preferably 10 to 40% by mass.
It is preferable for the acrylonitrile content to be in the above range since the heat resistance and solvent solubility will be in a suitable range, and the insulation will be stable and the reliability will be improved.
Below the lower limit of the above range, the heat resistance of the resin is lowered, and the heat resistance necessary for the semiconductor assembly process cannot be obtained. On the other hand, when the upper limit of the above range is exceeded, solubility in a solvent is lowered (workability for preparing an adhesive is lowered), which is not preferable. Also, the migration resistance is reduced.

Component (b):
As the phenol resin which is component (b), known resins can be used. However, since the adhesive temperature and the curing temperature of the adhesive can be lowered and sufficient adhesive strength can be obtained, a resol type alkylphenol is used. A phenolic resin containing is preferable.
It is more preferable to use a resol type phenol and a novolac type phenol in combination.
Furthermore, the mass ratio of the resol type phenolic resin to the novolac type phenolic resin is preferably 100: 5 to 100: 100, and more preferably 100: 10 to 100: 50.
The reason is that by using a resol type phenol and a novolac type phenol together, the tackiness of the surface can be suppressed, and the conveyance failure at the time of lead frame processing can be suppressed.
In addition, since novolak type phenol resin is inferior in curability by itself, if the mass ratio of novolac type phenol resin to resol type phenol is excessive, curability of the adhesive is lowered and migration resistance is lowered. It is not preferable.
Specific examples include resol-type pt-butylphenol and novolac-type pt-butylphenol.

Component (c):
As the compound containing two or more maleimide groups as component (c), it is necessary to use the compounds represented by the above formulas (1) and (2) in combination.
The reason is that the bonding temperature and the curing temperature of the adhesive can be lowered, and a high adhesive strength can be obtained. Moreover, heat stability improves by using together, and adhesiveness at the time of heating improves. Furthermore, the compatibility with other resins is increased and the migration resistance is excellent.
The mass ratio of the compounds represented by the above formulas (1) and (2) is preferably 3: 3 to 3:45, more preferably 3: 3.9 to 3: 19.5, More preferably, it is 1: 3 to 1: 7.

The liquid adhesive for electronic parts of the present invention preferably further contains component (d): a diamine compound, and component (d) may contain a compound represented by the following formula (3) or (4). More preferred.

(Wherein R ¹ represents a divalent aromatic group)

(Wherein R ² represents a propylene group or a phenoxymethylene group, and n represents an integer of 0 to 7)

This is because the curing temperature can be adjusted by using it as a maleimide group curing agent.

Examples of the compound represented by the above formula (3) include the following. In the present invention, the divalent aromatic group is not particularly limited. The divalent aromatic group means a divalent group including an aromatic group, and any group can be selected as necessary. For example, the number of phenyl groups is not limited, and may have a substituent as necessary. 3,3′-diaminobiphenyl, 3,4′-diaminobiphenyl, 4,4′-diaminobiphenyl, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 2, 2- (3,3′-diaminodiphenyl) propane, 2,2- (3,4′-diaminodiphenyl) propane, 2,2- (4,4′-diaminodiphenyl) propane, 2,2- (3 3'-diaminodiphenyl) hexafluoropropane, 2,2- (3,4'-diaminodiphenyl) hexafluoropropane, 2,2- (4,4'-diaminodiphenyl) hexafluoropropane, 3,3'-oxy Dianiline, 3,4'-oxydianiline, 4,4'-oxydianiline, 3,3'-diaminodiphenyl sulfide, , 4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 1,3-bis [ 1- (3-aminophenyl) -1-methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene, 1,4-bis [1- (3-amino Phenyl] benzene, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4 -Aminophenoxy) benzene, 3,3'-bis (3-aminophenoxy) diphenyl ether, 3,3'-bis (4-aminophenoxy) di Phenyl ether, 3,4'-bis (3-aminophenoxy) diphenyl ether, 3,4'-bis (4-aminophenoxy) diphenyl ether, 4,4'-bis (3-aminophenoxy) diphenyl ether, 4,4'- Bis (4-aminophenoxy) diphenyl ether, 1,4-bis [1- (4-aminophenyl) -1-methylethyl-bis (3-aminophenoxy) biphenyl, 3,3′-bis (4-aminophenoxy) Biphenyl, 3,4'-bis (3-aminophenoxy) biphenyl, 3,4'-bis (4-aminophenoxy) biphenyl, 4,4'-bis (3-aminophenoxy) biphenyl, 4,4'-bis (4-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4 -Aminophenoxy) phenyl] sulfone, 2,2-bis [3- (3-aminophenoxy) phenyl] propane, 2,2-bis [3- (4-aminophenoxy) phenyl] propane, 2,2-bis [ 4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [3- (3-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis [3- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis [4- (3-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis [4- (4 -Aminophenoxy) phenyl] hexafluoropropane, 9,9-bis (3-aminophenyl) fluorene, 9,9-bis (4-aminophen) Le) fluorene and the like.

The compound represented by the above formula (4) preferably has a weight average molecular weight of 200 to 7,000.
The reason is that it is easy to handle because it is easily dissolved in a solvent.

Examples of the compound represented by the above formula (4) include bis (3-aminopropyl) tetramethyldisiloxane, aminopropyl-terminated dimethylsiloxane tetramer or octamer, bis (3-aminophenoxymethyl) tetra Examples thereof include methyldisiloxane and the like, and these can be mixed and used.

The blending ratio of the liquid adhesive is preferably 10 to 900 parts by mass of the sum of the components (b) and (c) with respect to 100 parts by mass of the component (a). More preferably, the sum of component (b) and component (c) is in the range of 20 to 800 parts by mass, more preferably 50 to 400 parts by mass, and particularly preferably 100 to 400 parts by mass.
When the total sum of component (b) and component (c) is within the above range, the coating layer is cured after application, and the heat resistance, particularly Tg and Young's modulus of the adhesive layer are improved, which is suitable for the intended use.
Further, when the adhesive layer is cured up to the B stage, the adhesive layer itself is not brittle, the workability is improved, and the adhesiveness to the heat resistant film as the support tends to be good.
At this time, the mass ratio of the component (b) in the total of the components (b) and (c) is preferably 10 to 90% by mass, more preferably 20 to 53% by mass.
The mixing ratio of component (c) and component (d) is such that the amino group of component (d) is 0.01 to 2.0 molar equivalents relative to 1 molar equivalent of maleimide groups of component (c). More preferably, it is set in the range of 0.1 to 1.0 molar equivalent.
When the amino group equivalent of the component (d) is within the above range, when the adhesive layer is cured up to the B stage, the adhesive layer itself is not brittle and the workability is improved. The adhesion of the may improve.
Moreover, since it does not gel at the time of mixing, an adhesive agent can be adjusted.

The component (a), the component (b), the component (c), and the component (d) are mixed in a solvent that dissolves them.
The solvent can be selected according to need. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, sulfolane, hexamethylphosphoric triamide, 1,3-dimethyl- 2-imidazolidone, hexane, benzene, toluene, xylene, methyl ethyl ketone, acetone, diethyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, methyl cellosolve, cellosolve acetate, methanol, ethanol, propanol, isopropanol, methyl acetate, Examples include ethyl acetate, acetonitryl, methylene chloride, chloroform, carbon tetrachloride, chlorobenzene, dichlorobenzene, dichloroethane, and trichloroethane. From these, the type and amount can be appropriately selected and used so that each component is dissolved.

In the liquid adhesive, a reaction accelerator may be added as necessary to promote the addition reaction between the components (a) and the components (b).
Examples of reaction accelerators include diazabicyclooctane, or methyl ethyl ketone peroxide, cyclohexane peroxide, 3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, methyl acetoacetate peroxide, acetylacetone peroxide, 1, 1-bis (t-butylperoxy) -3,3,5 trimethylhexane, 1,1-bis (t-butylperoxy) -cyclohexane, 2,2-bis (t-butylperoxy) octane, n- Butyl-4,4-bis (t-butylperoxy) valate, 2,2-bis (t-butylperoxy) butane, t-butyl hydroperoxide, cumene hydroperoxide, di-isopropylbenzene hydroperoxide, p- Nthane hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide , Di-cumyl peroxide, α, α′-bis (t-butylperoxy-m-isopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5- Dimethyl-2,5-di (t-butylperoxy) hexyne, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, decanoyl peroxide, benzoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexa Noyl peroxide, succinic acid peroxide, 2,4-dichlorobenzoyl peroxide, m-toluoyl peroxide, di-isopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-n-propyl peroxydicarbonate, bis- (4-t -Butylcyclohexyl) peroxydicarbonate, di-myristyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, di-methoxyisopropyl peroxydicarbonate, di (3-methyl-3-methoxybutyl) per Oxydicarbonate, di-allyl peroxydicarbonate, t-butylperoxyacetate, t-butylperoxyisobutyrate, t-butylperoxypivalate, t-butylperoxyneodecanate, cumylperoxyneodecane , T-butylperoxy-2-ethylhexanate, t-butylperoxy-3,5,5-trimethylhexanate, t-butylperoxylaurate, t-butylperoxybenzoate, di-t- Butyl peroxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxymaleic acid, t-butylperoxyisopropyl carbonate, cumylperoxyoctate, t-hexylper Organic peroxides such as oxyneodecanate, t-hexylperoxypivalate, t-butylperoxyneohexanate, acetylcyclohexylsulfonyl peroxide, t-butylperoxyallyl carbonate, 1,2-dimethylimidazole, 1 -Methyl-2-ethylimidazole 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1 -Benzyl-2-phenylimidazole trimellitic acid salt, 1-benzyl-2-ethylimidazole, 1-benzyl-2-ethyl-5-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, 2-phenyl-4 -Benzylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-isopropylimidazole, 1-cyanoethyl 2-phenylimidazole, 1-cyanoethyl-2-methylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6- [2′-methylimidazolyl- (1 ')]-Ethyl-s-triazine, 2,4-diamino-6- [2'-ethyl-4-methylimidazolyl- (1')]-ethyl-s-triazine, 2,4-diamino-6- [ 2′-undecylimidazolyl- (1 ′)]-ethyl-s-triazine, 2-methylimidazolium isocyanuric acid adduct, 2-phenylimidazolium isocyanuric acid adduct, 2,4-diamino-6- [ 2′-Methylimidazolyl- (1 ′)]-ethyl-s-triazine-isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole 2-phenyl-4-benzyl-5-hydroxymethylimidazole, 4,4′-methylene-bis- (2-ethyl-5-methylimidazole), 1-aminoethyl-2-methylimidazole, 1-cyanoethyl -2-Phenyl-4,5-di (cyanoethoxymethyl) imidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazole / benzotriazole adduct, 1-aminoethyl-2-ethyl Imidazole, 1- (cyanoethylaminoethyl) -2-methylimidazole, N, N ′-[2-methylimidazolyl- (1) -ethyl] -adipoyldiamide, N, N′-bis- (2-methylimidazolyl) -1-ethyl) urea, N- (2-methylimidazolyl-1-ethyl) urea, N, N ′-[2-me Louis imidazolyl- (1) -ethyl] dodecandioyl diamide, N, N ′-[2-methylimidazolyl- (1) -ethyl] eicosane oil amide, 1-benzyl-2-phenylimidazole / hydrochloride, etc. Reaction accelerators such as imidazoles and triphenylphosphine. It may be used alone or in combination of two or more.

In addition, the liquid adhesive may contain a filler having a particle size of 1 μm or less in order to stabilize taping characteristics when applied to an adhesive tape.
Stabilization of taping characteristics means that when thermobonding the adhesive tape onto the leads, it prevents adhesive from sticking out of the end surface of the tape and maintains an appropriate thickness in the adhesive layer. Means to maintain.
The filler content is preferably set in the range of 4 to 40% by mass, preferably 9 to 24% by mass, based on the total solid content.
When the content is within the above range, the effect of stabilizing the taping characteristics is increased, the adhesive strength of the adhesive tape is improved, and the processability of laminate and the like is further improved.
Examples of fillers that can be used include silica, quartz powder, alumina, calcium carbonate, magnesium oxide, diamond powder, mica, fluororesin, and zircon powder.

In addition, the liquid adhesive is taken out after completion of the reaction, that is, after drying, if necessary, after being washed with an organic solvent, water, or a mixture of an organic solvent and water, and then again selected as needed. It may be dissolved in a solvent and used as an adhesive.
Organic solvents that can be used for washing include acetone, methyl ethyl ketone, hexane, benzene, toluene, xylene, methanol, ethanol, propanol, diethyl ether, tetrahydrofuran, methyl acetate, ethyl acetate, acetonitrile, methylene chloride, chloroform, carbon tetrachloride. , Chlorobenzene, dichlorobenzene, dichloroethane, trichloroethane and the like.

Next, the adhesive tape of the present invention will be described.
The adhesive tape of the present invention is characterized in that an adhesive layer formed by applying and drying the liquid adhesive for electronic parts is formed on at least one surface of a heat-resistant film or a peelable film.
In this case, the coating thickness is preferably in the range of 5 to 100 μm, particularly 10 to 50 μm.

Examples of the heat resistant film include heat resistant resin films such as polyimide, polyphenylene sulfide, polyether, polyparabanic acid, and polyethylene terephthalate, and composite heat resistant films such as epoxy resin-glass cloth and epoxy resin-polyimide-glass cloth. Among them, a polyimide film is particularly preferable.
The thickness of the heat resistant film is preferably set in the range of 7.5 to 130 μm, preferably 12.5 to 75 μm. The shape and size of the heat resistant film can be selected as necessary.
Within the above range, the waist of the adhesive tape becomes sufficient, and the punching operation becomes easy.

The peelable film preferably has a thickness of 1 to 200 μm, preferably 10 to 100 μm, and acts as a temporary support. The shape and size of the peelable film can be selected as necessary. Examples of the peelable film that can be used include a polypropylene film, a fluororesin film, a polyethylene film, a polyethylene terephthalate film, paper, and, in some cases, a film that has been made peelable with a silicone resin.
These peelable films desirably have a 90 ° peel strength in the range of 0.01 to 7.0 g / cm.
When the peel strength is within the above range, the peelable film is not easily peeled from the adhesive layer during conveyance of the adhesive tape, and the peelable film is peeled cleanly from the adhesive layer during use, and the workability is improved.
In addition, when an adhesive layer is formed on the heat resistant film, a protective film may be further provided on the adhesive layer.
As the protective film, the same film as the peelable film can be used.

Hereinafter, the present invention will be described in more detail based on examples.
<Example 1>
Component (a):
Acrylonitrile-butadiene copolymer (without carboxyl group, Mooney viscosity 70M _{1 + 4} 100 ° C., acrylonitrile content 27%) 100 parts by mass Component (b):
50 parts by mass of pt-butylphenol type resole phenolic resin (trade name: “CKM-1282”, manufactured by Showa Polymer Co., Ltd.) Copolymer type novolak phenolic resin (CKM-2400: Showa) Polymer Co., Ltd.) 20 parts by mass component (c):
30 parts by mass of the compound represented by the formula (1) commercially available 50 parts by mass of the compound represented by the formula (2) commercially available Component (d):
0.25 parts by mass of 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane The above ingredients were added to tetrahydrofuran and mixed well and dissolved to obtain a solid content. The liquid adhesive for electronic parts of Example 1 was obtained by adjusting to 30% by mass.
In addition, the molar equivalent of the amino group with respect to 1 molar equivalent of the maleimide group is 0.51.

<Example 2>
Ingredient (a) was changed as follows.
Component (a):
Carboxyl group-modified butadiene-acrylonitrile copolymer (carboxyl group equivalent 100, Mooney viscosity 60M _{1 + 4} 100 ° C., acrylonitrile content 27%) 100 parts by mass Otherwise, in the same manner as in Example 1, the liquid for electronic parts of Example 2 An adhesive was obtained.

<Example 3>
Ingredient (b) was changed as follows.
Component (b):
70 parts by mass of pt-butylphenol type resol phenol resin (CKM-1282, manufactured by Showa Polymer Co., Ltd.) The liquid adhesive for electronic parts of Example 3 was obtained in the same manner as in Example 1 except that.

<Example 4>
Ingredient (b) was changed as follows.
Component (b):
50 parts by mass of pt-butylphenol type resole phenolic resin (trade name: “CKM-1282”, manufactured by Showa Polymer Co., Ltd.) Copolymer type novolak phenolic resin (CKM-2400: Showa) (Manufactured by Kobunshi Co., Ltd.) 40 parts by mass A liquid adhesive for electronic parts of Example 4 was obtained in the same manner as in Example 1 except that.

<Example 5>
Ingredient (c) was changed as follows.
Component (c):
Commercially available 15 parts by mass of the compound represented by the formula (1) 65 parts by mass of the commercially available compound represented by the formula (2) In the same manner as in Example 1 except that the liquid adhesive for electronic parts of Example 5 was used. Obtained.

<Example 6>
Ingredient (d) was changed as follows.
Component (d):

Otherwise in the same manner as in Example 1, the liquid adhesive for electronic parts of Example 6 was obtained.

<Example 7>
Component (b) and component (c) were changed as follows.
Component (b):
16.6 parts by mass of pt-butylphenol type resol phenolic resin (trade name: “CKM-1282”, manufactured by Showa Polymer Co., Ltd.) Copolymer type novolak phenolic resin (CKM-2400) of pt-butylphenol and Bis-A : Showa Polymer Co., Ltd.) 6.7 parts by mass Component (c):
10 parts by mass of the commercially available compound represented by the formula (1) 16.7 parts by mass of the commercially available compound represented by the formula (2) In the same manner as in Example 1 except that, the liquid adhesive for electronic parts of Example 7 An agent was obtained.

<Example 8>
Component (b) and component (c) were changed as follows.
Component (b):
33.3 parts by mass of pt-butylphenol type resol phenolic resin (trade name: “CKM-1282”, manufactured by Showa Polymer Co., Ltd.) Copolymer type novolak phenolic resin (CKM-2400) of pt-butylphenol and Bis-A : Showa Polymer Co., Ltd.) 13.4 parts by mass Component (c):
20 parts by mass of the commercially available compound represented by the formula (1) 33.3 parts by mass of the commercially available compound represented by the formula (2) In the same manner as in Example 1 except that, the liquid adhesive for electronic components of Example 8 An agent was obtained.

<Example 9>
Component (b) and component (c) were changed as follows.
Component (b):
pt-Butylphenol type resole phenolic resin (trade name: “CKM-1282”, Showa Kogyo Co., Ltd.) 133.3 parts by mass Copolymerization type novolak phenolic resin (CKM-2400) of pt-butylphenol and Bis-A : Showa Polymer Co., Ltd.) 53.4 parts by mass Component (c):
80 parts by mass of the commercially available compound represented by the formula (1) 133.3 parts by mass of the commercially available compound represented by the formula (2) In the same manner as in Example 1 except that, the liquid adhesive for electronic parts of Example 9 An agent was obtained.

<Example 10>
Component (b) and component (c) were changed as follows.
Component (b):
26-part by mass of pt-butylphenol type resol phenol resin (trade name: “CKM-1282”, Showa Kogyo Co., Ltd.) Copolymer type novolak phenol resin (CKM-2400) of pt-butylphenol and Bis-A : Showa Polymer Co., Ltd.) 106.7 parts by mass Component (c):
160 parts by mass of a commercially available compound represented by the formula (1) 266.7 parts by mass of a commercially available compound represented by the formula (2) In the same manner as in Example 1 except that, the liquid adhesive for electronic parts of Example 10 An agent was obtained.

<Example 11>
Component (b) and component (c) were changed as follows.
Component (b):
85.7 parts by mass of pt-butylphenol type resol phenolic resin (trade name: “CKM-1282”, manufactured by Showa Polymer Co., Ltd.) Copolymer type novolak phenolic resin (CKM-2400) of pt-butylphenol and Bis-A : Showa Polymer Co., Ltd.) 34.3 parts by mass Component (c):
11.2 parts by mass of a commercially available compound represented by the formula (1) 18.8 parts by mass of a commercially available compound represented by the formula (2) In the same manner as in Example 1 except that, for the electronic component of Example 11. A liquid adhesive was obtained.

<Example 12>
Component (b) and component (c) were changed as follows.
Component (b):
32.1 parts by mass of pt-butylphenol type resole phenolic resin (trade name: “CKM-1282”, manufactured by Showa Polymer Co., Ltd.) Copolymer type novolak phenolic resin (CKM-2400) of pt-butylphenol and Bis-A : Showa Polymer Co., Ltd.) 12.9 parts by mass Component (c):
Commercially available compound represented by the formula (1) 39.4 parts by mass Commercially available compound represented by the formula (2) 65.6 parts by mass Other than that, in the same manner as in Example 1, the electronic component of Example 12 A liquid adhesive was obtained.

<Example 13>
Component (b) and component (c) were changed as follows.
Component (b):
21.4 parts by mass of pt-butylphenol type resole phenolic resin (trade name: “CKM-1282”, manufactured by Showa Polymer Co., Ltd.) Copolymer type novolak phenolic resin (CKM-2400) of pt-butylphenol and Bis-A : Showa Polymer Co., Ltd.) 8.6 parts by mass Component (c):
45 parts by mass of the commercially available compound represented by the formula (1) 75 parts by mass of the commercially available compound represented by the formula (2) In the same manner as in Example 1 except that, the liquid adhesive for electronic components of Example 13 was used. Obtained.

<Example 14>
Component (b) and component (c) were changed as follows.
Component (b):
10.7 parts by mass of pt-butylphenol type resole phenolic resin (trade name: “CKM-1282”, manufactured by Showa Kogyo Co., Ltd.) Copolymer type novolak phenolic resin (CKM-2400) of pt-butylphenol and Bis-A : Showa Polymer Co., Ltd.) 4.3 parts by mass Component (c):
50.6 parts by mass of a commercially available compound represented by the formula (1) 84.4 parts by mass of a commercially available compound represented by the formula (2) Other than that, in the same manner as in Example 1, the electronic component of Example 14 A liquid adhesive was obtained.

<Example 15>
Ingredient (c) was changed as follows.
Component (c):
5 parts by mass of a commercially available compound represented by the formula (1) 75 parts by mass of a commercially available compound represented by the formula (2) In the same manner as in Example 1 except that, the liquid adhesive for electronic parts of Example 15 was used. Obtained.

<Example 16>
Ingredient (c) was changed as follows.
Component (c):
Commercially available 10 parts by weight of the compound represented by the formula (1) 70 parts by weight of the commercially available compound represented by the formula (2) In the same manner as in Example 1, except that the liquid adhesive for electronic components of Example 16 was used. Obtained.

<Example 17>
Ingredient (c) was changed as follows.
Component (c):
Commercially available 20 parts by weight of the compound represented by the formula (1) 60 parts by weight of the commercially available compound represented by the formula (2) In the same manner as in Example 1, except that the liquid adhesive for electronic components of Example 17 was used. Obtained.

<Example 18>
Ingredient (c) was changed as follows.
Component (c):
40 parts by mass of the commercially available compound represented by the formula (1) 40 parts by mass of the commercially available compound represented by the formula (2) In the same manner as in Example 1, except that the liquid adhesive for electronic parts of Example 18 was used. Obtained.

<Comparative Example 1>
Ingredient (c) was changed as follows.
Component (c):
80 parts by mass of a commercially available compound represented by the formula (1) In the same manner as in Example 1 except for the above, a liquid adhesive for electronic parts of Comparative Example 1 which does not contain the compound represented by the formula (2) was obtained. .

<Comparative Example 2>
Ingredient (c) was changed as follows.
Component (c):
80 parts by mass of a commercially available compound represented by the formula (2) In the same manner as in Example 1 except for the above, a liquid adhesive for electronic parts of Comparative Example 2 containing no compound represented by the formula (1) was obtained. .

Table 1 shows the main conditions of the examples and comparative examples.

The liquid adhesives for electronic parts of Examples 1 to 18 and Comparative Examples 1 and 2 were applied to both sides of the polyimide film so that the thickness of the adhesive layer after drying was 20 μm, and the hot air circulation dryer was used. And then dried at 160 ° C. for 5 minutes to produce adhesive tapes using the adhesives of Examples 1 to 18 and Comparative Examples 1 and 2.

Next, using the adhesive tapes using the adhesives of Examples 1 to 18 and Comparative Examples 1 and 2, the lead frame used for the semiconductor package shown in FIG. Assembled.
Punching of adhesive tape: The adhesive tape was punched into a ring shape with a mold.
Temporary adhesion of adhesive tape: A plain was placed on a hot plate, and the tape punched into a ring shape was pressed against the plane with a metal rod and temporarily adhered.
The temporary bonding conditions were 140 ° C./2 seconds / 4 Kgf / cm ² .
Lead frame assembly: The plane on which the adhesive tape is temporarily bonded in the above process and the lead frame (Cu material) main body are aligned, heated and pressed on a heated hot plate, and the lead frame (Cu material) and the plane are bonded with the adhesive tape. Pasted together.
The bonding conditions were 140 ° C./2 seconds / 4 Kgf / cm ² .
Adhesive tape cure: Placed in a hot-air circulating oven substituted with nitrogen and heat-cured.
The conditions for thermosetting were 200 ° C./1 hour.

Next, a lead frame (Cu material) bonded to the produced plane was used to assemble a semiconductor package according to the following procedure.
Die bonding: A semiconductor chip was bonded to a plane portion of a lead frame bonded to a plane using a silver bonding paste, and cured at 150 ° C. for 2 hours.
Wire bonding: A wire bonder was used to wire the wire pad on the semiconductor chip and the silver plating portion at the end of the inner lead wire of the lead pin with a gold wire.
Molding: Transfer molded with an epoxy molding agent.
Finishing process: Processes such as homing, die cutting, and plating of the outer lead part were performed to finish the package.

(Evaluation)
<Low temperature bonding and curing>
The adhesive tapes of Examples 1 to 18 and Comparative Examples 1 and 2 were evaluated whether or not they could be easily and quickly adhered to an adherend, that is, a plane or a lead pin.
Specifically, the 90 ° peel strength (adhesive force) at room temperature of a 10 mm wide tape after the adhesive tape was attached (taped) to a copper plate at 100 ° C., 140 ° C., or 180 ° C. was measured.
The results are shown in Table 2.

The adhesive strength was 4.2 N / cm or more, and <low temperature adhesion, curing> was evaluated according to the following criteria.
A: Bondable at 100 ° C. Excellent in practical use.
○: Can be bonded at 140 ° C. There is no practical problem.
Δ: Can be bonded at 180 ° C. Practical possible.
×: Cannot be bonded at 180 ° C. There are practical problems.
Table 5 shows the evaluation results of low-temperature adhesion and curing.

<Heat resistance>
Evaluation was based on voids and shear adhesive strength as described below.
(void)
When the adhesive was cured, it was visually determined by a microscope whether or not the voids generated in the adhesive were at a level that would cause a practical problem.
Specifically, after affixing (taping) an adhesive tape to a copper plate at 140 ° C., the humidity was stored at 30 ° C./70% RH for 72 hours to obtain a test sample.
Then, the test sample was placed on a heater block at 160 ° C. for 1 minute, and the state of voids between the tape and the copper plate was visually determined with a microscope.
(Shear adhesive strength)
[Test specimen preparation]
The adhesive tape cut to a width of 5 mm and a length of 75 mm was affixed to an end (a central part of one piece) of a 20 mm × 20 mm copper plate at 140 ° C. (taping).
The sticking area was 25 mm ² (5 mm × 5 mm size), and the length of the tape not attached to the copper material was 70 mm.
[Measurement of shear bond strength]
After fixing the test body on a 160 ° C. heater block, the unattached portion of the tape on the copper plate was connected to a universal tensile testing machine, and the shear bond strength was measured.
The distance between the chuck of the copper plate-tension tester at the time of measurement was 50 mm, and the tensile speed was 50 mm / min.
In addition, in order to stabilize measurement temperature, the test body was fixed on the heater block, and measurement was started after 5 seconds.
The results are shown in Table 3.

And <heat resistance> was evaluated according to the following criteria.
A: No void and shear adhesive strength of 40 N / cm ² or more (no problem in practical use)
○: No void and shear adhesive strength of 20 N / cm ² or more and less than 40 N / cm ² (no problem in practical use)
Δ: No void and shear bond strength of less than 20 N / cm ² (no problem in practical use)
X: Void and shear bond strength less than 20 N / cm ² (practical problem)
Table 5 shows the evaluation results of heat resistance.

<Dimensional stability of lead pin>
When the adhesive was cured, the evaluation was made based on whether or not the positional deviation of the lead pins was at a level that was problematic in practice.
Specifically, an adhesive tape is punched into a square (ring) with an outer dimension of 22 mm x an inner dimension of 20 mm using a mold, and then attached to a predetermined position of an evaluation lead frame (QFP 208 pin) with a hot press. It was.
The hot press conditions were a pressure of 5 kgf / cm ² and a pressure bonding time of 0.3 seconds. The pressure bonding temperature was 120 ° C. to 140 ° C. (the temperature at which the adhesive thickness on the lead pin was 15 to 18 μm was regarded as the temperature at which application was possible).
The lead frame used has a pin pitch of 168 μm.
[Measurement of lead pin misalignment]
Immediately after the tape was applied and after treatment at 200 ° C./1 hour in a hot air circulation oven, the pin pitch of the lead frame was measured with a microscope.
The pressure bonding temperature and the measurement results are shown in Table 4.

Then, <dimensional stability of lead pin> was evaluated according to the following criteria.
○: The pin pitch immediately after tape application and the pin pitch after treatment at 200 ° C./1 hour in a hot air circulating oven are both within 168 μm ± 10%.
(Triangle | delta): The pin pitch immediately after tape sticking, and the pin pitch after a 200 degreeC / 1 hour process in a hot-air circulation type oven both exceeded 168 micrometers +/- 10% and within 168 micrometers +/- 15%.
X: The values of the pin pitch immediately after tape application and the pin pitch after treatment at 200 ° C./1 hour in a hot air circulation oven exceeded 168 μm ± 15%.

Table 5 shows the evaluation results of the dimensional stability of the lead pins.

<Reliability>
The package obtained as described above was subjected to a PCBT test (Pressure Cooker Biased Test).
Conditions were 100 volts applied, 130 ° C., 2 atm, 85% RH, and an electrical reliability test was performed.
And <reliability> was evaluated according to the following criteria.
○: No short circuit at 240 hours ×: Short circuit at 240 hours Table 5 shows the reliability evaluation results.

<Migration resistance>
After the reliability test, the package was polished to expose the adhesive surface and observed with a microscope.
And <migration resistance> was evaluated according to the following criteria.
A: Dendrite cannot be confirmed, and there is no discoloration of the lead pin.
○: Dendrite cannot be confirmed, but lead pin is discolored.
X: With dendrite Table 5 shows the evaluation results of migration resistance.

<Workability>
The handling properties (curling and running properties) during use, such as taping of the adhesive tape at the time of assembling the lead frame, and the tackiness of the adhesive surface of the adhesive tape were evaluated for <workability> according to the following criteria.
○: Very easy to work without tack △: Easy to work with little tack ×: Hard to work with tack

Evaluation results are shown in Table 5.

(Evaluation results)
As can be seen from Table 5, the adhesive tapes of Examples 1 to 18 are all Δ or more and have no practical problem.
In particular, Example 5, Example 9, Example 16, and Example 17 were excellent in low-temperature adhesion, curing, heat resistance, and migration resistance. Furthermore, Example 2 was excellent in low-temperature adhesion, curing, heat resistance, and migration resistance.
On the other hand, the adhesive tape of Comparative Example 1 was short-circuited in the reliability test, and there was a practical problem with dendrite in terms of migration resistance.
Moreover, the adhesive tape of Comparative Example 2 had practical problems with respect to heat resistance and lead pin dimensional stability.

It is possible to provide a liquid adhesive for electronic parts and an adhesive tape that can be bonded and cured at low temperatures, have sufficient heat resistance and reliability, and have excellent migration resistance.

1 Semiconductor chip 2 Plain 3 Lead pin 4 Bonding wire 5 Resin 6 Adhesive layer 7 Die pad 8 Electrode

Claims (14)

1. In organic solvent,
   Component (a) acrylonitrile-butadiene copolymer,
   Component (b) phenol resin,
   Component (c) is a liquid adhesive in which a compound containing two or more maleimide groups is dissolved, and the component (c) includes a compound represented by the following formula (1) and a compound represented by the following (2) The liquid adhesive for electronic components characterized by the above-mentioned.
   

   

   
2. The liquid adhesive for electronic parts according to claim 1, wherein the component (a) has a Mooney viscosity of 50 to 90M _{1 + 4 at} 100 ° C and an acrylonitrile content of 5 to 50% by mass.
3. 2. The liquid adhesive for electronic components according to claim 1, wherein the component (a) is an acrylonitrile-butadiene copolymer having a carboxyl group.
4. 2. The liquid adhesive for electronic parts according to claim 1, wherein the component (b) is a phenol resin containing a resol type alkylphenol.
5. The liquid adhesive for electronic parts according to claim 1, wherein the component (b) uses a resol type phenol and a novolac type phenol in combination.
6. The liquid adhesive for electronic parts according to claim 1, wherein the component (c) has a mass ratio of the compounds represented by the formulas (1) and (2) of 3: 3 to 3:45. .
7. The sum of component (b) and component (c) is 10 to 900 parts by weight with respect to 100 parts by weight of component (a), and component (b) in the sum of component (b) and component (c) 2. The liquid adhesive for electronic parts as claimed in claim 1, wherein the mass ratio of (1) is 10 to 90% by mass.
8. Furthermore, component (d) diamine compound is contained, The liquid adhesive for electronic components of Claim 1 characterized by the above-mentioned.
9. The liquid adhesive for electronic components according to claim 8, wherein the component (d) is a compound represented by the following formula (3).
   

   

   (Wherein R ¹ represents a divalent aromatic group)
10. 9. The liquid adhesive for electronic parts according to claim 8, wherein the component (d) is a compound represented by the following formula (4) and has a weight average molecular weight of 200 to 7,000.
    

    

    (Wherein R ² represents a propylene group or a phenoxymethylene group, and n represents an integer of 0 to 7)
11. 2. The liquid adhesive for electronic parts according to claim 1, wherein a filler having a particle size of 1 μm or less is contained in an amount of 4 to 40% by mass of the total solid content.
12. An adhesive tape comprising an adhesive layer formed by applying and drying the liquid adhesive for electronic parts according to claim 1 on at least one surface of a heat resistant film.
13. The adhesive tape according to claim 12, wherein the heat resistant film is a polyimide film.
14. An adhesive tape comprising an adhesive layer formed by applying and drying the liquid adhesive for electronic parts according to claim 1 on at least one surface of the peelable film.

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