JP2006182919A - Adhesive film for semiconductor and semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a semiconductor device using an adhesive film for a semiconductor bonding a semiconductor element to a supporting member for loading the semiconductor element having a difference in level of a substrate such as an organic substrate at a low temperature without insufficiency of embedding properties and having excellent reflow resistance. <P>SOLUTION: The adhesive film for the semiconductor is composed of a resin composition containing an acrylic ester copolymer, a polyfunctional epoxy compound, a curing agent and a molecular compound of a tetra-substituted phosphonium and a polyfunctional phenol compound. The adhesive film for the semiconductor makes the adhesiveness compatible with flow properties after thermal history by including the molecular compound of the tetra-substituted phosphonium and the polyfunctional phenol compound as a curing promoter for the epoxy resin. The method for producing the semiconductor device comprises joining the semiconductor element to the supporting member for loading the semiconductor element by using the adhesive film for the semiconductor. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an adhesive film for a semiconductor and a semiconductor device using the same.

  In recent years, there has been a demand for higher density and higher integration of semiconductor devices in response to higher functionality of electronic devices. In order to meet such requirements, for example, a lead-on-chip (LOC) structure in which a lead is bonded onto a semiconductor element is employed as a structure of a semiconductor device. In this LOC structure, since the semiconductor element and the lead frame are bonded, the bonding reliability at the bonded portion greatly affects the reliability of the semiconductor package.

  Conventionally, paste adhesives have been used as adhesives for semiconductors. However, particularly in recent semiconductor packages, the chip is stacked in multiple stages on the chip, thereby realizing a reduction in size, thickness and capacity of the package. In such a package, the paste adhesive has problems such as a problem that occurs when the wire sticks out of the chip and the thickness of the adhesive layer is difficult to control. In order to solve such problems, film adhesives have been used.

Here, in the LOC structure, a film adhesive obtained by applying an adhesive and a heat-resistant substrate such as a hot-melt adhesive film using a polyimide resin has been used (Patent Document 1).
However, since the hot-melt adhesive film needs to be bonded at a high temperature, it may cause thermal damage to a high-density semiconductor element and lead frame.

  In addition, in order to realize high density and high integration of semiconductor devices, use of organic substrates such as bismaleimide-triazine substrates and polyimide substrates instead of lead frames is increasing. On the surface of such an organic substrate, there is a level difference on the surface more than the lead frame, and step embedding to eliminate this level difference is a problem when using a film adhesive.

In the case of using a film-like adhesive, the step filling is often performed by using the pressure at the time of encapsulating the mold material. In this case, the adhesive layer is required to have flowability at the encapsulation temperature. . However, as the number of chips increases, the adhesive layer hardens due to excessive heat history when wire bonding or adhesive layer cures, and it is not possible to obtain sufficient flow properties to allow the step of the substrate to be recessed. There was a problem. In addition, problems such as void entrainment may occur. Furthermore, even if the flowability is satisfied, since the resin is partially cured by the heat history, there is a problem that the adhesiveness is insufficient, and there is a problem of achieving both curability and adhesiveness.
JP-A-6-264035

  An object of the present invention is to provide a semiconductor adhesive film capable of bonding a semiconductor element and a support member for mounting a semiconductor element such as a lead frame or an organic substrate, and having excellent curability and adhesion after a thermal history. That is.

Such an object is achieved by the present invention described in the following [1] to [7].
[1] (A) Acrylic ester copolymer,
(B) a polyfunctional epoxy compound,
(C) a curing agent, and
(D) a molecular compound of a tetra-substituted phosphonium and a polyfunctional phenol compound,
The adhesive film for semiconductors characterized by including.
[2] The adhesive film for a semiconductor according to [1], wherein the tetra-substituted phosphonium of component (D) is tetraphenylphosphonium.
[3] The adhesive for semiconductor according to [1] or [2], wherein the polyfunctional phenol compound of component (D) comprises a hydroxybenzene compound, a biphenol compound, a bisphenol compound, a hydroxynaphthalene compound, a phenol novolac resin, or a phenol aralkyl resin. the film.
[4] The adhesive film for a semiconductor according to any one of [1] to [3], wherein the component (C) is a phenolic curing agent.
[5] An adhesive film for a semiconductor, wherein a melt viscosity at 175 ° C. after heat-treating the semiconductor adhesive film at 150 ° C. for 1 hour is 500 [Pa · s] or more and 5000 [Pa · s] or less.
[6] An adhesive film for a semiconductor, wherein the adhesive film for a semiconductor is heat treated at 150 ° C. for 1 hour and further treated at 175 ° C. for 4 hours, and then has an elastic modulus at 240 ° C. of 1 to 50 MPa.
[7] A semiconductor device comprising a semiconductor element, a semiconductor element mounting support member, and an adhesive for joining them,
A semiconductor device, wherein the adhesive is the adhesive film for a semiconductor according to any one of [1] to [6].

  ADVANTAGE OF THE INVENTION According to this invention, the semiconductor element and the support member for semiconductor element mounting, such as a lead frame or an organic substrate, can be adhere | attached, and the adhesive film for semiconductors excellent in the sclerosis | hardenability and adhesiveness after a heat history is provided. can do.

  The present invention comprises (A) an acrylic ester copolymer, (B) a polyfunctional epoxy compound, (C) a curing agent, and (D) a molecular compound of a tetra-substituted phosphonium and a polyfunctional phenol compound. This is an adhesive film for semiconductors. The following is an example, and the present invention is not limited to the following. Below, each component of the adhesive film for semiconductors of this invention is demonstrated in detail.

(A) Acrylic acid ester copolymer means a polymer containing acrylic acid, methacrylic acid, these esters, and other derivatives as monomers. Specific examples include acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate. A copolymer of an acrylic monomer other than an acrylic monomer such as acrylonitrile and an acrylic monomer is also included in the acrylic ester copolymer.
Since the (A) acrylic acid ester copolymer of the present invention has a low glass transition temperature, the initial adhesion of the adhesive film for a semiconductor can be improved by adding this.

  In the present invention, an acrylic copolymer having a functional group such as an epoxy group, a hydroxyl group, a carboxyl group, or a nitrile group is preferred. Thereby, the adhesiveness to adherends, such as a semiconductor element, can be improved more. Specific examples of the compound having a functional group include glycidyl methacrylate having a glycidyl ether group, hydroxy methacrylate having a hydroxyl group, carboxy methacrylate having a carboxyl group, and acrylonitrile having a nitrile group.

  As the acrylic ester copolymer used in the present invention, a copolymer of ethyl acrylate, acrylonitrile, glycidyl methacrylate, a copolymer of ethyl acrylate, butyl acrylate, acrylonitrile, glycidyl methacrylate, ethyl acrylate, butyl acrylate, hydroxyethyl acrylate, acrylic Examples include acid copolymers.

  When an epoxy group-containing monomer is used in the copolymer, the content of the monomer is preferably from 0.1 to 30% by weight, more preferably from 0.5 to 20% by weight, based on the entire acrylic ester copolymer. . When the content is less than the lower limit, the effect of improving the adhesion may be reduced, and when the content exceeds the upper limit, the adhesive force is too strong and the effect of improving the workability may be reduced.

  The weight average molecular weight of the (A) acrylate ester copolymer used in the present invention is not particularly limited, but is preferably 100,000 or more, particularly preferably 150,000 to 1,000,000. When the weight average molecular weight is within the above range, the film forming property of the adhesive film for a semiconductor can be improved.

  (B) The polyfunctional epoxy compound refers to an epoxy compound having two or more epoxy groups in one molecule, and refers to monomers, oligomers, and polymers in general containing an epoxy group. For example, biphenyl type epoxy resin, bisphenol type epoxy resin, stilbene type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, triphenolmethane type epoxy resin, alkyl-modified triphenolmethane type epoxy resin, triazine nucleus-containing epoxy resin , Trisphenol type epoxy resin, dicyclopentadiene-modified phenol type epoxy resin, and the like, and these may be used alone or in combination.

  Among these epoxy resins, crystalline epoxy resins having a melting point of 50 to 150 ° C. are preferable. Such a crystalline epoxy resin has a rigid structure such as a biphenyl skeleton, a bisphenol skeleton, and a stilbene skeleton in the main chain, and among these epoxy resins that are relatively low molecules, the melting point is 50 to 150 ° C. Crystalline epoxy resins are preferred. Such a crystalline epoxy resin has a rigid structure such as a biphenyl skeleton, a bisphenol skeleton, and a stilbene skeleton in the main chain, and has a relatively low molecular weight.

  (B) Although content of a polyfunctional epoxy resin compound is not specifically limited, 10 to 100 weight% of the whole said acrylic ester copolymer is preferable, and 20 to 50 weight% is especially preferable.

(C) The curing agent acts as a curing agent for the polyfunctional epoxy resin (B). In the present invention, a phenolic curing agent is preferred. Specifically, a phenol aralkyl resin having a phenylene or diphenylene skeleton, which is a copolycondensation product of phenols and aldehydes or ketones, which is a copolycondensation reaction product of phenols and bisphenols, phenols and dimethoxyparaxylene, etc. Mononuclear resorcin, catechol, etc. can be used if they cause a curing reaction, but since the definition of “phenol” is generally a compound in which a hydrogen atom bonded to an aromatic ring is substituted with a hydroxyl group, A copolycondensation product of a hydroxyl group-containing compound derived from a condensed polycyclic aromatic and a carbonyl compound is also included. Among these phenolic resins, the water absorption of the cured product is small due to the small number of hydroxyl groups in the molecule, the molecule has an appropriate flexibility, the reactivity in the curing reaction is good, and the viscosity can be lowered. In view of this, phenol aralkyl resins are particularly preferred.

  The ratio of the polyfunctional epoxy resin (B) of the present invention to the curing agent (C) acting as a curing agent is 0.5 to 2 mol of phenolic hydroxyl group, preferably 1 to 2 mol of epoxy group, By adjusting the molar ratio to about 0.8 to 1.2, the curability, the heat resistance of the cured product, the electrical characteristics, etc. are improved.

  The molecular compound of (D) tetra-substituted phosphonium and polyfunctional phenol compound used in the present invention is not a simple mixture but a compound having a structure such as a salt structure or a supramolecular structure.

Among the molecular compounds of (D) tetra-substituted phosphonium and polyfunctional phenol compound used in the present invention, tetra-substituted phosphonium is a compound in which four alkyl groups or aromatic compounds are coordinated to a phosphorus atom. The tetra-substituted phosphonium is preferably tetraphenylphosphonium.
The substituent of the tetra-substituted phosphonium which is one of the constituent components is not limited at all, and the substituents may be the same or different from each other. For example, a tetra-substituted phosphonium ion having a substituted or unsubstituted aryl group or alkyl group as a substituent is preferable because it is stable against heat and hydrolysis. Specifically, tetraphenylphosphonium, tetratolylphosphonium, tetraethylphenylphosphonium, tetramethoxyphenylphosphonium, tetranaphthylphosphonium, tetrabenzylphosphonium, ethyltriphenylphosphonium, n-butyltriphenylphosphonium, 2-hydroxyethyltriphenylphosphonium, Examples include trimethylphenylphosphonium, methyldiethylphenylphosphonium, methyldiallylphenylphosphonium, and tetra-n-butylphosphonium.

Among the molecular compounds of (D) tetra-substituted phosphonium and a polyfunctional phenol compound used in the present invention, the polyfunctional phenol compound has a phenolic hydroxyl group, and at least one of the hydroxyl groups is dehydrogenated to remove the phenoxide type compound. It is what has become.
Preferred are hydroxybenzene compounds, biphenol compounds, bisphenol compounds, hydroxynaphthalene compounds, phenol novolac resins, and phenol aralkyl resins.

  Examples of the polyfunctional phenol compound that is a constituent component of the molecular compound (D) of the present invention include bis (4-hydroxy-3,5-dimethylphenyl) methane (commonly called tetramethylbisphenol F), 4,4′-. Sulfonyl diphenol and 4,4′-isopropylidene diphenol (commonly called bisphenol A), bis (4-hydroxyphenyl) methane, bis (2-hydroxyphenyl) methane, (2-hydroxyphenyl) (4-hydroxyphenyl) Three types of methane and a mixture of bis (4-hydroxyphenyl) methane, bis (2-hydroxyphenyl) methane, and (2-hydroxyphenyl) (4-hydroxyphenyl) methane (for example, Honshu Chemical Industry Co., Ltd.)・ Bisphenols such as bisphenol FD), 1,2-benzene Various isomers of dihydroxybenzenes such as all, 1,3-benzenediol, 1,4-benzenediol, trihydroxybenzenes such as 1,2,4-benzenetriol, and dihydroxynaphthalenes such as 1,6-dihydroxynaphthalene And various isomers of biphenols such as 2,2′-biphenol and 4,4′-biphenol.

  The molecular compound of (D) tetra-substituted phosphonium and polyfunctional phenolic compound used in the present invention has a phosphonium-phenoxide type salt in the structure as described above, but the phosphonium-organic acid anion salt type in the prior art. The difference from the compound is that in the molecular compound (D) of the present invention, a higher-order structure by hydrogen bonds surrounds ionic bonds. In the salt in the conventional technique, the reactivity is controlled only by the strength of the ionic bond, whereas in the molecular compound (D) of the present invention, the enclosure by the higher-order structure of the anion protects the active site at room temperature. On the other hand, at the molding stage, the higher-order structure is broken, so that the active sites are exposed, and so-called latency that expresses reactivity is imparted.

  The molecular compound of (D) tetra-substituted phosphonium and polyfunctional phenol compound used in the present invention is 0.01 to 10 parts by weight with respect to 100 parts by weight of the total weight of the aforementioned compound (B) and compound (C), About 0.1 to 5 parts by weight is preferable because of a good balance between curability, storage stability and other characteristics.

  The adhesive film for semiconductor of the present invention may contain a coupling agent as necessary. Thereby, the adhesiveness between the resin and the adherend and between the resin and the silica interface can be improved. Examples of the coupling agent include silane-based, titanium-based, and aluminum-based, among which silane-based coupling agents are preferable.

  Examples of the coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, β- (3,4 epoxy cyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxy. Propylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N- β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl -Γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane and the like.

  Although content of the said coupling agent is not specifically limited, 0.01-10 weight part is preferable with respect to 100 weight part of said epoxy resins, and 0.1-10 weight part is especially preferable. If the content is less than the lower limit, the effect of adhesion may be insufficient, and if it exceeds the upper limit, it may cause outgassing or voids.

  The present invention provides an adhesive film for a semiconductor, wherein the semiconductor adhesive film has a melt viscosity at 175 ° C. of 500 [Pa · s] or more and 5000 [Pa · s] or less after heat treatment at 150 ° C. for 1 hour. is there.

  The melt viscosity can be measured, for example, by using a rheometer, which is a viscoelasticity measuring device, by applying shear shear at a frequency of 1 Hz to a sample in a film state at a heating rate of 10 ° C./min.

  If the melt viscosity at 175 ° C. is 500 [Pa · s] or less, the melt viscosity at the time of heating may be excessively reduced and foaming may be caused by heat. Insufficient step filling is not sufficient.

  The heat history for 1 hour at 150 ° C. is a heat history assuming a wire bond or a thermosetting process, and the flowability at 175 ° C. is important because the mold material sealing temperature is usually 175 ° C.

  It is preferable that the elastic modulus at 240 ° C. after the semiconductor adhesive film is heat treated at 150 ° C. for 1 hour and further treated at 175 ° C. for 4 hours is 1 to 50 MPa.

  If the elastic modulus at 240 ° C. is less than 1 MPa, peeling or voids may occur due to insufficient strength at the time of reflow resistance, and if it exceeds 50 MPa, the stress relaxation property is undesirably lowered.

  The method for producing an adhesive film for a semiconductor according to the present invention includes, for example, dissolving the resin composition in a solvent such as methyl ethyl ketone, acetone, toluene, dimethylformaldehyde to form a varnish, followed by a comma coater, a die coater, a gravure coater, etc. It is obtained by coating on a carrier film using and drying.

  Although the thickness of the said adhesive film for semiconductors is not specifically limited, 3-100 micrometers is preferable and 5-70 micrometers is especially preferable. When the thickness is within the above range, it is particularly easy to control the thickness accuracy.

  In the method for producing a semiconductor device of the present invention, first, the adhesive film for semiconductor of the present invention is attached to the back surface of a silicon wafer under mild conditions, and then a silicon wafer with a die attach film is laminated on the dicing film and placed on the dicing device. Using a cutting means such as a dicing saw, the silicon wafer with an adhesive film for semiconductor is cut into individual pieces to obtain a semiconductor chip as a single die.

  In addition, the semiconductor adhesive film of the present invention is coated on a carrier film, dried, then laminated on a dicing tape, and then bonded to a silicon wafer under mild conditions, and using a cutting means such as a dicing saw, the semiconductor adhesive film It is also possible to obtain a semiconductor chip obtained by cutting a piece of silicon wafer into individual dies.

  Next, the semiconductor device of the present invention will be described. The obtained adhesive film for semiconductor can be used for bonding a semiconductor element and a metal lead frame, a substrate in which glass fiber is impregnated with an epoxy resin, a polyimide substrate, a bismaleimide-triazine resin substrate, or other organic substrate.

  As bonding conditions, the semiconductor element and the semiconductor mounting support member are pressure-bonded via the adhesive film at a temperature of 80 to 200 ° C. for a time of 0.1 to 30 seconds. Thereafter, if necessary, the semiconductor device can be obtained through wire bonding and sealing with a sealing material.

EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited to this. First, examples of the adhesive for semiconductors and comparative examples will be described.
Example 1
1. Preparation of Adhesive Film Resin Varnish for Semiconductor Acrylic ester copolymer containing glycidyl group as an acrylic ester copolymer (manufactured by Nagase ChemteX Corp., SG-80H, Tg: 15 ° C., weight average molecular weight: 350,000 ) 100 parts by weight, 30 parts by weight of a crystalline cresol novolac epoxy resin (EOCN-1020-80, epoxy equivalent 200 g / eq, manufactured by Nippon Kayaku Co., Ltd.) as a polyfunctional epoxy resin, and an epoxy resin (NC6000, epoxy) Equivalent 197 g / eq, Nippon Kayaku Co., Ltd. 50 parts by weight, phenol curing agent (MEH7500, Meiwa Kasei Co., Ltd.) 40 parts by weight, tetra-substituted phosphonium as a molecular compound of tetra-substituted phosphonium and polyfunctional phenol compound As a polyfunctional phenol compound with tetraphenylphosphosphonium as 4,4′sulfonyldiphenol compound as a product, 0.2 part by weight of γ-glycidoxypropyltrimethoxysilane (KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) as a coupling agent, and methyl ethyl ketone (MEK). The resin varnish having a resin solid content of 40% was obtained.

2. Manufacture of adhesive film for semiconductor After applying the above-mentioned resin varnish to a polyethylene terephthalate film (manufactured by Oji Paper Co., product number RL-07, thickness 38 μm) as a carrier film using a comma coater, it is dried at 70 ° C. for 10 minutes. Thus, an adhesive film for a semiconductor having a thickness of 25 μm with a carrier film was obtained.
The melt viscosity at 175 ° C. after heat-treating the obtained adhesive film for semiconductor at 150 ° C. for 1 hour was 1800 [Pa · s]. Further, the elastic modulus after heat treatment at 175 ° C. for 4 hours was 20 MPa.

(Example 2)
The same procedure as in Example 1 was carried out except that the composition of the adhesive film resin varnish for semiconductor was as follows.
100 parts by weight of an acrylate copolymer containing a glycidyl group as an acrylate copolymer (manufactured by Nagase ChemteX Corp., SG-80H, Tg: 15 ° C., weight average molecular weight: 350,000), polyfunctional 30 parts by weight of cresol novolac epoxy resin (EOCN-1020-80, epoxy equivalent 200 g / eq, manufactured by Nippon Kayaku Co., Ltd.), epoxy resin (NC6000, epoxy resin 197 g / eq, manufactured by Nippon Kayaku Co., Ltd.) ) 50 parts by weight, phenolic curing agent (MEH7500, manufactured by Meiwa Kasei Co., Ltd.) 40 parts by weight, tetrasubstituted phosphonium as a molecular compound of tetrasubstituted phosphonium and polyfunctional phenolic compound, tetraphenylphosphosphonium as polyfunctional phenolic compound Bis (4-hydroxyphenyl) methane And compound 0.1 part by weight, as the coupling agent γ- glycidoxypropyltrimethoxysilane (KBM403, manufactured by Shin-Etsu Chemical Co.) was used and 1 part by weight.
The melt viscosity at 175 ° C. after heat-treating the obtained adhesive film for semiconductor at 150 ° C. for 1 hour was 2200 [Pa · s]. Further, the elastic modulus after heat treatment at 175 ° C. for 4 hours was 18 MPa.

(Example 3)
The same procedure as in Example 1 was carried out except that the composition of the adhesive film resin varnish for semiconductor was as follows.
100 parts by weight of an acrylate copolymer containing a glycidyl group as an acrylate copolymer (manufactured by Nagase ChemteX Corp., SG-80H, Tg: 15 ° C., weight average molecular weight: 350,000), polyfunctional 30 parts by weight of crystalline cresol novolac epoxy resin (EOCN-1020-80, epoxy equivalent 200 g / eq, manufactured by Nippon Kayaku Co., Ltd.) as an epoxy resin, epoxy resin (NC6000, epoxy equivalent 197 g / eq, Nippon Kayaku) (Made by Co., Ltd.) 50 parts by weight, Phenol curing agent (XLC-2L, Mitsui Chemicals, Inc.) 70 parts by weight, tetrasubstituted phosphonium as a molecular compound of tetrasubstituted phosphonium and polyfunctional phenolic compound as tetrasubstituted phosphonium Bis (4-hydroxyphenyl) as a polyfunctional phenol compound Tan compound 0.1 part by weight, .gamma.-glycidoxypropyltrimethoxysilane as a coupling agent (KBM403, manufactured by Shin-Etsu Chemical Co.) 0.1 parts by weight was used and.
The melt viscosity at 175 ° C. after heat-treating the obtained adhesive film for semiconductor at 150 ° C. for 1 hour was 3300 [Pa · s]. Further, the elastic modulus after heat treatment at 175 ° C. for 4 hours was 15 MPa.

Example 4
The same procedure as in Example 1 was carried out except that the composition of the adhesive film resin varnish for semiconductor was as follows.
100 parts by weight of an acrylic acid ester copolymer containing hydroxyl groups as an acrylic acid ester copolymer (manufactured by Nagase ChemteX Corp., SG-708, Tg: ° C., weight average molecular weight: 800,000), and polyfunctional epoxy resin As a crystalline cresol novolac epoxy resin (EOCN-1020-80, epoxy equivalent 200 g / eq, manufactured by Nippon Kayaku Co., Ltd.) and epoxy resin (NC6000, epoxy equivalent 197 g / eq, Nippon Kayaku Co., Ltd.) )) 50 parts by weight, phenol curing agent (MEH7500, manufactured by Meiwa Kasei Co., Ltd.) 30 parts by weight, tetra-substituted phosphonium as a molecular compound of tetra-substituted phosphonium and polyfunctional phenol compound, tetra-phenyl phosphophosphonium as polyfunctional phenol compound 4,4′sulfonyldiphenol compound as 1 part by weight and 0.1 part by weight of γ-glycidoxypropyltrimethoxysilane (KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) were used as a coupling agent.
The melt viscosity at 175 ° C. after heat-treating the obtained adhesive film for semiconductor at 150 ° C. for 1 hour was 3000 [Pa · s]. Further, the elastic modulus after heat treatment at 175 ° C. for 4 hours was 15 MPa.

(Comparative Example 1)
The same procedure as in Example 1 was carried out except that the composition of the adhesive film resin varnish for semiconductor was as follows.
100 parts by weight of an acrylic acid ester copolymer containing hydroxyl groups as an acrylic acid ester copolymer (manufactured by Nagase ChemteX Corp., SG-708, Tg: 6 ° C., weight average molecular weight: 800,000), and polyfunctional epoxy As resin, crystalline cresol novolac epoxy resin (EOCN-1020-80, epoxy equivalent 200 g / eq, Nippon Kayaku Co., Ltd.) 30 parts by weight, epoxy resin (NC6000, epoxy equivalent 197 g / eq, Nippon Kayaku ( 50 parts by weight), phenol curing agent (MEH7500, Meiwa Kasei Co., Ltd.) 30 parts by weight, imidazole compound (2PHZ-PW, Shikoku Kasei Co., Ltd., average particle size 2 μm) as a curing accelerator 2 parts by weight and γ-glycidoxypropyltrimethoxysilane (KBM403, Shin-Etsu Chemical Co., Ltd.) as a coupling agent ) Made by 0.2 parts by weight.
The melt viscosity at 175 ° C. after heat-treating the obtained adhesive film for semiconductor at 150 ° C. for 1 hour was 8000 [Pa · s]. Further, the elastic modulus after heat treatment at 175 ° C. for 4 hours was 18 MPa.

(Comparative Example 2)
The same procedure as in Example 1 was carried out except that the composition of the adhesive film resin varnish for semiconductor was as follows.
100 parts by weight of an acrylate copolymer containing a glycidyl group as an acrylate copolymer (manufactured by Nagase ChemteX Corp., SG-80H, Tg: 15 ° C., weight average molecular weight: 350,000), polyfunctional 30 parts by weight of crystalline cresol novolac epoxy resin (EOCN-1020-80, epoxy equivalent 200 g / eq, manufactured by Nippon Kayaku Co., Ltd.) as an epoxy resin, epoxy resin (NC6000, epoxy equivalent 197 g / eq, Nippon Kayaku) 50 parts by weight manufactured by Co., Ltd., 30 parts by weight phenol curing agent (MEH7500, manufactured by Meiwa Kasei Co., Ltd.), and an imidazole compound (2PHZ-PW, manufactured by Shikoku Kasei Co., Ltd., average particle size 2 μm) 0 as a curing accelerator 2 parts by weight and γ-glycidoxypropyltrimethoxysilane (KBM403, Shin-Etsu) as a coupling agent 1 part by weight of Chemical Co., Ltd. was dissolved in methyl ethyl ketone (MEK) to obtain a resin varnish having a resin solid content of 40%.
The melt viscosity at 175 ° C. after heat-treating the obtained adhesive film for semiconductor at 150 ° C. for 1 hour was 7500 [Pa · s]. Further, the elastic modulus after heat treatment at 175 ° C. for 4 hours was 20 MPa.

Next, a semiconductor device will be described.
(Example 1 to Example 4)
3. Semiconductor Device Manufacturing The adhesive film with carrier tape obtained in Examples 1 to 4 was attached to the adhesive film side with the back surface of a 5-inch 550 μm wafer at 60 ° C. to obtain a wafer with carrier tape and adhesive film.
Thereafter, the dicing film was peeled off from the carrier tape and attached to the wafer. Then, using a dicing saw, the semiconductor wafer to which the adhesive film is bonded is diced (cut) into a semiconductor element size of 5 mm × 5 mm square at a spindle rotation speed of 30,000 rpm and a cutting speed of 50 mm / sec. A semiconductor element to which the tape was bonded was obtained. Next, the semiconductor element pushed up from the back surface of the dicing sheet and peeled between the carrier tape adhesive film layers and bonded to the adhesive film was pressure-bonded to a bismaleimide-triazine substrate at 130 ° C., 1 MPa for 1.0 second, and die-bonded, Heated at 150 ° C. for 1 hour, sealed with resin, and cured at 175 ° C. for 4 hours to obtain 10 semiconductor devices.
(Comparative Examples 1 to 2)
The same procedure as in Example 1 was performed except that the adhesive film with carrier tape obtained in Comparative Examples 1 and 2 was used as the adhesive film for semiconductor.

The following evaluation was performed regarding the adhesive film for semiconductor and the semiconductor device obtained in each Example and Comparative Example. The evaluation items are shown together with the contents. The obtained results are shown in Table 1.
1. Embeddability A glass chip with a die attach film was die-bonded at 130 ° C./1 MPa / 1 s on a bismaleimide-triazine substrate having an average of 10 μm unevenness, and heat-treated at 150 ° C. for 1 hour. Thereafter, pressurization was performed with a load of 175 ° C./7 MPa / 30 s, and the embedding property of unevenness was observed. The embedding property was evaluated as a percentage of the embedded area of the original film area.
A: Embeddability is 90% or more B: Embeddability is less than 70 to 90% Δ: Embeddability is less than 50 to 70% ×: Embeddability is less than 50%

2. Initial adhesiveness of adhesive film Adhesiveness between die attach film and bismaleimide-triazine substrate is as follows: semiconductor element bonded to die attach film and bismaleimide-triazine substrate under conditions of 130 ° C, 1 MPa, 1.0 sec. The shear strength between the chip and the lead frame was evaluated in the state of bonding and untreated (before curing).
A: Shear strength is 1.0 MPa or more. O: Shear strength is 0.75 or more and less than 1.0 MPa. Δ: Shear strength is 0.5 or more and less than 0.75 MPa. Shear strength is less than 0.5 MPa

3. Adhesiveness after moisture absorption treatment The semiconductor devices obtained in each Example and Comparative Example were subjected to moisture absorption treatment at 85 ° C./85% RH / 168 hours, and then the shear strength between the semiconductor element and the lead frame was evaluated.
A: Shear strength is 1.0 MPa or more. O: Shear strength is 0.75 or more and less than 1.0 MPa. Δ: Shear strength is 0.5 or more and less than 0.75 MPa. Shear strength is less than 0.5 MPa

4). Crack resistance Crack resistance is determined by scanning ultrasonic flaw detection by subjecting the semiconductor devices obtained in the examples and comparative examples to moisture absorption treatment at 85 ° C./60% RH / 168 hours, followed by IR reflow at 260 ° C. three times. Machine (SAT). Each code is as follows.
◎: No crack at all ○: No crack at 7/10 or more △: There are 9/10 or more cracks and less than 7/10 ×: There are 10/10 cracks

（１）テトラ置換ホスホニウムと４，４’スルホニルジフェノール分子化合物
（２）テトラ置換ホスホニウムとビス（４−ヒドロキシフェニル）メタン分子化合物

(1) Tetra-substituted phosphonium and 4,4′sulfonyldiphenol molecular compound (2) Tetra-substituted phosphonium and bis (4-hydroxyphenyl) methane molecular compound

  As is clear from Table 1, Examples 1 to 4 were excellent in embedding property, initial property and adhesiveness after moisture absorption, and excellent in crack resistance.

Claims (7)

(A) an acrylic ester copolymer,
(B) a polyfunctional epoxy compound,
(C) a curing agent, and
(D) a molecular compound of a tetra-substituted phosphonium and a polyfunctional phenol compound,
The adhesive film for semiconductors characterized by including.   The adhesive film for a semiconductor according to claim 1, wherein the tetra-substituted phosphonium of component (D) is tetraphenylphosphonium.   The adhesive film for semiconductor according to claim 1 or 2, wherein the polyfunctional phenol compound of component (D) contains a hydroxybenzene compound, a biphenol compound, a bisphenol compound, a hydroxynaphthalene compound, a phenol novolac resin, or a phenol aralkyl resin.   The adhesive film for semiconductor according to any one of claims 1 to 3, wherein the component (C) is a phenolic curing agent.   An adhesive film for a semiconductor, wherein a melt viscosity at 175 ° C. after heat-treating the semiconductor adhesive film at 150 ° C. for 1 hour is 500 [Pa · s] or more and 5000 [Pa · s] or less.   An adhesive film for a semiconductor, wherein the adhesive film for a semiconductor is heat treated at 150 ° C. for 1 hour, and further treated at 175 ° C. for 4 hours, and then has an elastic modulus at 240 ° C. of 1 to 50 MPa. A semiconductor device comprising a semiconductor element, a semiconductor element mounting support member, and an adhesive for joining them,
The semiconductor device whose adhesive is the adhesive film for semiconductors in any one of Claims 1 thru | or 6.