JP2000230113A - Epoxy resin composition, laminate film and semiconductor apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both a self-polymerization type and phenol curing type epoxy resin compositions having reduced glass transition temperatures of uncured materials without lowering heat resistance, moisture resistance and low stress properties of cured materials, a laminate film of two or more layers composed of at least one layer of thin film having excellent flexibility and workability, using the epoxy resin composition, and to provide a semiconductor apparatus produced by sealing a gap between a semiconductor element and a substrate and the surface of the semiconductor element with the filmy epoxy resin composition. SOLUTION: The epoxy resin composition characteristically comprises (A) an epoxy resin compound of <=10 wt.% of a di-nuclide and >=50 wt.% of the total of tri- to penta-nuclides and having <=1.7 ratio of weight-average molecular weight to number-average molecular weight, (B) an inorganic filler, (C) a curing agent and (D) optionally a phenol resin and has (D) <15 deg.C glass transition temperature of uncured material. A flexible film having excellent workability is obtained by using the resin composition and a laminate film of two or more layers constituted of one layer of the epoxy resin composition to which another layer is stuck depending upon uses can be obtained. A semiconductor element is covered with the film to give a semiconductor apparatus having excellent head resistance, moisture resistance and low stress properties.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-polymerized or phenol-curable epoxy resin composition, a laminated film using the epoxy resin composition which is effective for semiconductor encapsulation, and a semiconductor device encapsulated by the film.

[0002]

2. Description of the Related Art In recent years,
Electronic devices tend to be smaller and lighter at remarkable speeds.
In this trend, semiconductor devices, which are the brains of electronic devices, also tend to be smaller and lighter, and ultimately a CSP (Chip Size) that reduces the mounting area to a chip size.
Package) implementation has been proposed.

[0003] Epoxy resins are widely used as materials for assembling semiconductor packages because of their excellent adhesiveness, heat resistance and moisture resistance. In recent years, along with the diversification of the package system as described above, not only as a conventional sealing material, but also a coating material and a die bonding material,
Alternatively, it is used as an underfill material or the like. Most of these materials are diluted with a solvent or paste-like.

[0004] Among them, those diluted with a solvent require considerable care in removing the solvent that evaporates during use from the viewpoint of health care and safety of workers, which is a factor of cost increase. .

[0005] In addition, as a method of using the coating material,
A method of covering the surface of a semiconductor element with only a thin film of an epoxy resin composition and sealing it, or a method of screen printing with a paste-like epoxy resin composition have been proposed. These materials include pastes such as conventionally known acid anhydride-curable epoxy resin compositions and amine-curable epoxy resin compositions, or these paste-like epoxy resin compositions on a film. Staged and filmed products are used.

[0006] On the other hand, the die bond material or the underfill material has conventionally been mostly in the form of paste.
Recently, a paste-like die-bonding material formed into a film has been widely used. As a method of use, a film is pressure-bonded onto a lead frame or a substrate, and a semiconductor element is adhered thereon and cured. Most of these materials include acid anhydride-curable epoxy resin compositions and amine-curable epoxy resin compositions that are well known in the art.

[0007] These B-staged films are easier to handle than paste-like materials, and are very promising methods for contributing to the simplification of the semiconductor device assembly process. The resin composition and the amine-curable epoxy resin composition have the preservability of the uncured material,
Since the cured product has insufficient moisture resistance and high temperature characteristics, it is insufficient as a material for directly coating a semiconductor element surface with a thin film.

On the other hand, when a self-polymerization type epoxy resin composition, particularly imidazoles, is used as a curing catalyst, or a phenol curing type epoxy resin composition is less effective than an acid anhydride curing type or an amine curing type. Although the preservability of the cured product and the moisture resistance and high-temperature properties of the cured product are good, it is difficult to control the progress of the reaction and obtain a semi-cured B-staged film. In order to obtain a good film, it is necessary to lower the softening point of the epoxy resin or phenol resin curing agent as a raw material. In this case, a dilemma occurs in that the heat resistance of the cured product is insufficient.

The present invention has been made to solve the above problems, and (1) lowers the glass transition temperature of an uncured product without lowering the heat resistance, moisture resistance and low stress of the cured product. A self-polymerized and phenol-cured epoxy resin composition, (2) a laminated film of two or more layers comprising at least one thin film film having good flexibility and good workability using the epoxy resin composition of (1); (3) It is an object of the present invention to provide a semiconductor device in which a gap between a semiconductor element and a substrate and a surface of the semiconductor element are sealed with the film-like epoxy resin composition of (2).

[0010]

Means for Solving the Problems and Embodiments of the Invention The present inventors have conducted intensive studies to achieve the above object, and as a result,
An epoxy resin, an inorganic filler, a curing catalyst, wherein the binuclear body is 10% by weight or less, the total amount of the 3 to 5 nuclei is 50% by weight or more, and the weight average molecular weight / number average molecular weight is 1.7 or less; Further contains a phenolic resin as necessary, an epoxy resin composition in which the softening temperature of the uncured material is less than 15 ° C., preferably, in the case of a self-polymerization type, using imidazoles as a curing catalyst, and a phenol-curable type In this case, it is preferable to use a phenol resin having a glass transition temperature of less than 15 ° C. and containing no monomer, more preferably an aromatic polymer and an organopolysiloxane represented by the following composition formula (1). Good at room temperature by incorporating a copolymer obtained by reacting with siloxane and using an epoxy resin composition having a volatile component of 0.1% by weight or less. Very workability that good film is obtained from having elasticity and flexibility, and, by covering the semiconductor element by the film, heat resistance,
The present inventors have found that a semiconductor device having good moisture resistance and low stress and a small amount of voids can be obtained, thereby completing the present invention.

R _a R ′ _b SiO _{(4-ab) / 2} (1) (wherein R is a monovalent hydrocarbon group containing a hydrogen atom, an amino group, an epoxy group, a hydroxy group or a carboxy group or Represents an alkoxy group, R ′ represents a substituted or unsubstituted monovalent hydrocarbon group, and a and b represent 0.001 ≦ a ≦
1, 0.9 ≦ b ≦ 2 and 1 ≦ a + b ≦ 3 are positive numbers. The number of silicon atoms in one molecule is 2 to 1000, and the number of functional groups R directly connected to silicon atoms in one molecule is one or more. )

Accordingly, the present invention firstly relates to (A) a binuclear compound having a weight ratio of 10% by weight or less, a total amount of 3 to 5 nuclei particles of 50% by weight or more, and a weight average molecular weight / number average molecular weight (B) an inorganic filler, (C) a curing catalyst, (D) a phenolic resin as required, and a glass transition temperature of an uncured product of less than 15 ° C. Self-polymerizing or phenol-curable epoxy resin composition. Secondly, when the component (D) does not contain the phenolic resin, the component (C) curing catalyst is an imidazole. Product, or a phenolic resin of component (D), the glass transition temperature of which is less than 15 ° C., and
The above-mentioned phenol-curable epoxy resin composition containing no monomer, thirdly, an aromatic polymer and the following composition formula (1)
The above epoxy resin composition containing a copolymer obtained by reacting with an organopolysiloxane represented by the following formula: R _a R ′ _b SiO _{(4-ab) / 2} (1) (where R is A monovalent hydrocarbon group or an alkoxy group containing a hydrogen atom, an amino group, an epoxy group, a hydroxy group or a carboxy group; R ′ represents a substituted or unsubstituted monovalent hydrocarbon group; 001 ≦ a
It is a positive number satisfying ≦ 1, 0.9 ≦ b ≦ 2, and 1 ≦ a + b ≦ 3. The number of silicon atoms in one molecule is 2 to 100.
0, and the number of functional groups R directly bonded to silicon atoms in one molecule is one or more. Fourth, the present invention provides the above epoxy resin composition, wherein the volatile component in the uncured product is 0.1% by weight or less.

[0013] The present invention also relates to the present invention, wherein at least one layer is formed of the epoxy resin composition and has a thickness of 20 to 150.
Disclosed is a laminated film having a thickness of 2 μm and composed of two or more layers, and a semiconductor device in which the surface of a semiconductor element is sealed with a cured product of the laminated film.

Hereinafter, the present invention will be described in detail. The epoxy resin that can be used in the present invention has a binuclear body of 10
% By weight (i.e., 0 to 10% by weight), the total amount of 3 to 5 nuclei is 50% by weight or more (i.e., 50 to 100% by weight), and the weight average molecular weight / number average molecular weight is 1.7. Any epoxy resin having the following (i.e., 1.0 to 1.7) can be used. Here, the epoxy resin used in the present invention has one epoxy group for each nucleus. Therefore, the n-nucleus has n epoxy groups in one molecule.

Examples of this type of epoxy resin include phenol novolak type epoxy resins represented by the following formula (2), cresol novolak type epoxy resins, and novolak type epoxy resins such as cocondensed novolak type epoxy resins of phenol and cresol. A trishydroxyphenylalkane type epoxy resin such as a trishydroxyphenylmethane type epoxy resin or a trishydroxyphenylpropane type epoxy resin represented by the formula (3) is desirable. Among them, particularly, the total amount of the 3 to 5 nuclei is 60% by weight or more (60 to 100% by weight),
The ratio of the trinuclear body to the total amount of the nuclei is 60% by weight or more (60 to 100% by weight), and the weight average molecular weight / number average molecular weight is 1.5 or less (1.0 to 1.5). Further, those having a softening temperature of less than 15 ° C., particularly less than 10 ° C., particularly, a phenol novolak type epoxy resin or a cresol novolak type epoxy resin are desirable. If the content of the binuclear substance is too large relative to the entire epoxy resin, the glass transition temperature of the cured product is lowered, and the heat resistance is lowered. Further, even if the content of the binucleate is proper, 3 to 5
If the total amount of the cores is too small, the proportion of the hexanucleus or higher increases, the glass transition temperature of the uncured material increases, the flexibility of the film is impaired at room temperature, and the film is damaged. appear.

[0016]

Embedded image (Wherein, R ¹ is a hydrogen atom or a methyl group, G is a glycidyl group represented by the following formula, R ² is a hydrogen atom or a bromine atom, n
Is 0 or a natural number, preferably an integer of 0 to 5, particularly preferably 1, 2 or 3. )

[0017]

Embedded image

[0018]

Embedded image (Wherein, R ¹ is a hydrogen atom or a methyl group, G is a glycidyl group represented by the following formula, R ² is a hydrogen atom or a bromine atom, m
Is 0 or a natural number, preferably an integer of 0 to 5, particularly preferably 0 or 1. )

[0019]

Embedded image

In addition to the above epoxy resins, bisphenol type epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, cyclopentadiene type epoxy resin, phenol aralkyl type epoxy resin, A conventionally known epoxy resin such as a biphenylaralkyl type epoxy resin may be used in combination. In this case, the amount of these epoxy resins is in a range where the glass transition temperature of the epoxy resin composition does not become 15 ° C. or higher.

The total chlorine content in these epoxy resins is
Preferably it is 1500 ppm or less, especially 1000 ppm or less. Further, it is preferable that the extraction water chlorine in 20 hours at 120 ° C. and 50% epoxy resin concentration is 5 ppm or less. If the total chlorine content and the amount of extracted water chlorine are large, the moisture resistance reliability of the semiconductor may be reduced.

The kind of the inorganic filler that can be used in the present invention is not particularly limited, and is arbitrarily selected according to the application. For example, one kind of natural silica such as crystalline silica and amorphous silica, synthetic high-purity silica, synthetic spherical silica, talc, mica, silicon nitride, boron nitride, alumina, etc., or conductive particles such as Ag powder Alternatively, two or more types can be used. The shape of the inorganic filler is not particularly limited, such as a spherical shape, a crushed shape, and an amorphous shape, but a spherical shape is preferable. The amount of the inorganic filler is determined by the total amount of the resin (that is, the amount of the epoxy resin and the amount of the phenolic resin and the copolymer when the copolymer of the phenolic resin or the aromatic polymer and the organopolysiloxane described later is compounded). The total amount is preferably 50 to 1000 parts by weight, more preferably 100 to 400 parts by weight, based on 100 parts by weight including the amount of the polymer. The particle size of the inorganic filler is limited by the thickness of the laminated film. Desirably, the maximum particle size is less than the film thickness, and the average particle size is less than 1/2.

Usually, the maximum particle size is less than 150 μm, preferably less than 75 μm, and the average particle size is 0.1 to 70 μm.
m, preferably about 1 to 30 μm.
The average particle diameter can be determined, for example, as a weight average value (or median diameter) by a laser light diffraction method.

The epoxy resin composition of the present invention can be prepared either as a self-polymerizing type in which a curing agent such as a phenolic resin is not blended or a phenolic curing type in which a phenolic resin is used as a curing agent. A curing catalyst is blended as an essential component.

In this case, the type of the curing catalyst that can be used in the self-polymerizable epoxy resin composition is not particularly limited as long as it can homopolymerize the epoxy resin. Examples thereof include imidazoles and tertiary amines. One or two or more of these can be used, and among them, imidazoles (imidazole compounds) are particularly preferable in consideration of the storage stability of the uncured product. Examples of imidazoles include 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole,
-Phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-hydroxymethylimidazole, 2-phenyl-4,5-di (hydroxymethyl) -imidazole and the like, and tertiary amines Examples include triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine and 1,8-
Cycloamidine compounds such as diazabicyclo (5.4.0) undecene-7 and the like can be mentioned.

In the case of a phenol-curable epoxy resin composition, in addition to the above imidazoles and tertiary amines, triphenylphosphine, tributylphosphine, tri (p)
-Tolyl) phosphine, tri (p-methoxyphenyl) phosphine, tri (p-ethoxyphenyl) phosphine, organic phosphine compounds such as triphenylphosphine / triphenylborane and salts thereof, and quaternary compounds such as tetraphenylphosphonium / tetraphenylborate Organic phosphorus compounds such as phosphonium compounds and salts thereof can be used.

The amount of the curing catalyst is preferably 0.1 part by weight based on 100 parts by weight of the epoxy resin (when phenolic resin is blended, the total amount of epoxy resin and phenolic resin).
The amount is from 0.01 to 10 parts by weight, more preferably from 0.1 to 5 parts by weight. If the blending amount of the curing catalyst is too small, curing failure may occur at the time of heat molding, and if it is too large, problems such as a decrease in storage stability may occur.

In the phenol-curable epoxy resin composition, a phenol resin is blended as a curing agent.

The phenolic resin used in the present invention may be any resin having at least one, preferably two or more phenolic hydroxyl groups in the molecule.
Although the molecular weight distribution is not particularly limited as in the case of the epoxy resin, in order to achieve a glass transition temperature of the epoxy resin composition (uncured product) of less than 15 ° C., the glass transition temperature of the phenol resin is reduced. Is preferably less than 15 ° C., particularly preferably less than 10 ° C. In order to avoid a decrease in the heat resistance of the cured product, it is desirable that the cured product does not contain a monomer (that is, a mononuclear body). In consideration of such conditions, the monomer (mononuclear) is not contained, and the total amount of the dinuclear to tetranuclear is 80% by weight or more (that is, 80 to 100% by weight). The proportion of binuclides in the total amount of nuclei is 40% by weight or more,
Those having a glass transition temperature of less than 0% by weight and a glass transition temperature of less than 15 ° C, particularly less than 10 ° C, particularly a phenol novolak resin or a cresol novolak resin (the following structural formula (4)) are desirable. Here, the phenolic resin used in the present invention has one phenolic hydroxyl group for each nucleus. Therefore, the n nucleus has n phenolic hydroxyl groups in one molecule. . When the proportion of the binuclear substance in the total amount of the 2 to 4 nuclei is 70% by weight or more, the glass transition temperature of the cured product becomes low, and the heat resistance may be reduced. When the proportion of dinuclear is less than 40% by weight and the proportion of dinuclear is less than 80% by weight, the proportion of trinuclear or higher is increased, and Has a high glass transition temperature, and at room temperature, the flexibility of the film may be impaired and the film may be damaged.

[0030]

Embedded image (In the formula, R ¹ is a hydrogen atom or a methyl group, R ² is a hydrogen atom or a bromine atom, n is 0 or a natural number, preferably an integer of 0 to 5, particularly preferably 0, 1 or 2.)

In addition to the above-mentioned phenolic resins, bisphenol-type phenolic resins such as bisphenol-A-type resins and bisphenol-F-type resins, co-condensed novolak resins of phenol and cresol, trishydroxyphenylmethane-type resins, trishydroxyphenylpropane-type resins, etc. A conventionally known phenol resin such as a trishydroxyphenylalkane type resin, a naphthalene type phenol resin, a cyclopentadiene type phenol resin, a phenol aralkyl resin, a biphenyl aralkyl type phenol resin may be used in combination, and in this case, the blending of these phenol resins The amount is such that the glass transition temperature of the epoxy resin composition is 15 ° C.
This is a range that does not exceed the above.

The compounding amount of the phenolic resin is 0.5 or more in an equivalent ratio to the compounding amount of the epoxy resin (that is, the molar ratio of the phenolic hydroxyl group in the phenolic resin to the epoxy group in the epoxy resin). It is desirably not more than 0.8, and more preferably not less than 0.8 and not more than 1.2.
If the amount of the phenolic resin is less than 0.5 or greater than 2.0 in equivalent ratio to the amount of the epoxy resin,
There is a possibility that a problem that the resin composition is not sufficiently cured and heat resistance is reduced may occur.

The epoxy resin composition of the present invention can contain pigments such as carbon black, dyes, flame retardants, coupling agents, thermoplastic resins and other additives depending on the application. .

The epoxy resin composition of the present invention is a flexible rubber at about room temperature (about 25 ° C.) in an uncured state, and therefore has a glass transition temperature of less than 15 ° C., more preferably less than 10 ° C. It is desirable that When the glass transition temperature of the uncured product is 15 ° C. or higher, there is a possibility that the flexibility of the film is impaired at room temperature, causing a problem that the film is damaged.

The epoxy resin composition of the present invention may contain a copolymer obtained by reacting an aromatic polymer with a specific organopolysiloxane, if necessary, in order to improve the low stress property. It is desirable to do.

Here, various compounds can be used as the aromatic polymer, and examples thereof include epoxy resins and phenol resins having the structures of the following formulas (5) and (6).

[0037]

Embedded image

[0038]

Embedded image (Wherein, R ¹ is a hydrogen atom or a methyl group, R ² is a hydrogen atom or a bromine atom, R ³ is a hydrogen atom or a glycidyl group represented by the following formula, n is 0 or a natural number, preferably an integer of 0 to 50, Particularly preferably, an integer of 1 to 20, m is 0 or a natural number, preferably an integer of 0 to 5, particularly preferably 0 or 1.
It is. )

[0039]

Embedded image

As the aromatic polymer, the following formula (7)
Alkenyl group-containing compounds (epoxy resins or phenol resins) having the structures of (9) to (9) can also be used.

[0041]

Embedded image (Wherein R ¹ is a hydrogen atom or a methyl group, R ² is a hydrogen atom or a bromine atom, R ³ is a hydrogen atom or a glycidyl group represented by the following formula, n and m are natural numbers, and preferably n + m is 2 to 5)
0, more preferably an integer of 2 to 20. )

[0042]

Embedded image

On the other hand, the organopolysiloxane is represented by the following composition formula (1). R _a R ′ _b SiO _{(4-ab) / 2} (1) (wherein R represents a hydrogen atom, an amino group, an epoxy group, a monovalent hydrocarbon group containing a hydroxy or carboxy group, or an alkoxy group) R ′ represents a substituted or unsubstituted monovalent hydrocarbon, and a and b represent 0.001 ≦ a ≦
1, 0.9 ≦ b ≦ 2 and 1 ≦ a + b ≦ 3 are positive numbers. Here, R reacts with the epoxy group, phenolic hydroxyl group or alkenyl group in the aromatic polymer,
It is a functional group capable of forming a copolymer, and the number of silicon atoms in one molecule is 2 to 1000, preferably 10 to 4
And a functional group R directly bonded to a silicon atom in one molecule.
Is 1 or more, preferably 2 to 5, particularly preferably 2. )

In this case, examples of the amino group-containing monovalent hydrocarbon group for R include the following.

[0045]

Embedded image (N; an integer from 1 to 3)

As the epoxy group-containing monovalent hydrocarbon group,
The following are mentioned.

[0047]

Embedded image (N; an integer from 1 to 3)

The following are examples of the hydroxy group-containing monovalent hydrocarbon group.

[0049]

Embedded image (M; integer of 0 to 3; n; integer of 1 to 3)

Examples of the carboxy group-containing monovalent hydrocarbon group include —C _X H _{2 X} COOH (X = 0 to an integer of 0 to 10), and examples of the alkoxy group include a methoxy group, an ethoxy group, and an n-propoxy group. Having 1 to 4 carbon atoms.

The substituted or unsubstituted monovalent hydrocarbon group for R ′ is preferably a group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group and an n-butyl group. , Isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, cyclohexyl group, octyl group, alkyl group such as decyl group, vinyl group, allyl group, propenyl group, alkenyl group such as butenyl group, phenyl group, Aryl groups such as a tolyl group; aralkyl groups such as a benzyl group and a phenylethyl group; and halogen-substituted monovalent hydrocarbon groups in which some or all of the hydrogen atoms of these hydrocarbon groups have been substituted with halogen atoms and the like. Can be. Among these, a methyl group, an ethyl group, a propyl group, and a phenyl group are particularly preferable.

Further, a and b are the values described above, but preferably 0.01 ≦ a ≦ 0.1, 1.8 ≦ b ≦ 2, 1.8.
5 ≦ a + b ≦ 2.1, the number of silicon atoms is preferably 10
400, more preferably 20 to 210.

Examples of such an organopolysiloxane include compounds having the following structures.

[0054]

Embedded image

In the formulas (10) and (11), R ′ represents the same unsubstituted or substituted monovalent hydrocarbon group as in the formula (1), preferably a methyl group or a phenyl group, X represents an amino group, an epoxy group, Represents a hydroxy or carboxy group-containing monovalent hydrocarbon group, and p is from 0 to 1000, preferably from 8 to 4
An integer of 00 and q represents an integer of 0 to 20, preferably 0 to 5.

Specific examples include the following diorganopolysiloxanes.

[0057]

Embedded image

The molecular weight of the above-mentioned organopolysiloxane is not particularly limited, but may be 100 to 7000.
0 is desirable. This is because when the molecular weight of the organopolysiloxane is 100 to 70000, when the obtained copolymer is blended with the epoxy resin composition, the copolymer is not compatible with the matrix and forms a fine sea-island structure. That's why. When the molecular weight is less than 100, the copolymer is compatible in the matrix, the sea-island structure disappears, and the molecular weight is 7000.
If it is larger than 0, the sea-island becomes large, and in any case, the low stress property of the cured product may be reduced.

As a method for obtaining the copolymer by reacting the aromatic polymer with the organopolysiloxane, a known method is employed.

The amount of the copolymer is from 0 to 1 part by weight per 100 parts by weight of epoxy resin (total of epoxy resin and phenol resin when phenol resin is mixed).
The amount is preferably about 00 parts by weight, more preferably about 1 to 50 parts by weight. Particularly in the case of the phenol-curable epoxy resin composition, the total amount of the phenolic hydroxyl groups is 0.5 or more with respect to the total amount of the epoxy groups in the above-described epoxy resin, the phenol resin and the copolymer as a whole.
It is desirably 2.0 or less, more preferably 0.1.
It is desirably 8 or more and 1.2 or less. When the total amount of the phenolic hydroxyl groups is out of the above range with respect to the total amount of the epoxy groups, the resin composition may not be sufficiently cured, and a problem such as a decrease in heat resistance may occur.

The epoxy resin composition of the present invention is prepared by uniformly stirring and mixing predetermined amounts of the above-mentioned components at 70 to 90 ° C.
After being mixed with a roll, a kneader, a continuous kneading device, or the like, which has been heated to a temperature below, the mixture can be cooled to a glass transition temperature or lower and crushed. The order of the components is not particularly limited.

The epoxy resin composition of the present invention is preferably used in the form of a film. In this case, the conditions at the time of heat molding are such that the pressure applied to the material is lower than that of the conventional solid resin transfer molding. Materials are extremely small and are often exposed to high temperatures rapidly compared to potting and underfill of liquid materials. Therefore, since the volatile components contained in the uncured material tend to remain as voids after curing, it is desired that the volatile components be extremely small. Specifically, it is desirable that the content of the volatile component is 0.1% by weight or less, preferably 0.01% by weight or less.

The epoxy resin composition of the present invention is effectively used for encapsulating a semiconductor. At this time, it is preferable to use the epoxy resin composition after processing it into a film, and particularly to use it as at least one layer of a laminated film having two or more layers. Is preferred.
In this case, the thickness of the film made of the epoxy resin composition of the present invention is preferably 20 to 150 μm. The material and thickness of the other layers are selected according to the use of the laminated film.

More specifically, for the purpose of protecting the layer formed of the epoxy resin composition of the present invention, a silicone sheet, a Teflon sheet, or a PET (polyethylene) coated with a release silicone or Teflon on the surface. A terephthalate) sheet or the like on one side or both sides, a laminated film, a layer of an adhesive for temporary adhesion at room temperature to a substrate or a semiconductor element, and a layer between the epoxy resin composition layer and the protective layer. Or a laminated film or the like sandwiched between both.

Incidentally, the laminated film of the present invention is produced by using a coater / laminator or the like used for the production of ordinary rubber sheets. At this time, the epoxy resin composition of the present invention is heated and pressurized and stretched as needed, and cut into a plate shape or cut into a tape shape depending on the use of the laminated film,
It can be manufactured by winding. This is further cut according to the application, and is used after removing the above-mentioned protective layer.

Although the semiconductor device using the laminated film of the present invention is not particularly limited, it is suitable for a small and thin semiconductor device such as a CSP, and particularly, an adhesive having a narrow gap between a chip and a substrate. It is effective for use in applications, and provides more reliable adhesion than conventional acid anhydride-curable or amine-curable materials. Also, the method of using the laminated film of the present invention is not particularly limited, but the film is cut into an appropriate size, temporarily press-bonded on a substrate, and after mounting a chip on the film, the whole is heat-pressed. A semiconductor device can be obtained by such a method. Here, the film may be preheated before the chip is mounted.

[0067]

According to the epoxy resin composition of the present invention, by controlling the molecular weight distribution of the epoxy resin (and preferably a phenol resin curing agent), the epoxy resin composition can be used without reducing the heat resistance and moisture resistance of the cured product. It is possible to lower the glass transition temperature of the cured product. Moreover, by using this epoxy resin composition, a film which is flexible and has good workability can be obtained. Further, the layer of this epoxy resin composition is made into one layer, and another layer is attached according to the application.
A laminated film having more than two layers can be obtained, and by covering a semiconductor element with this film, a semiconductor device having good heat resistance, moisture resistance, and low stress can be obtained.

[0068]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

Examples and Comparative Examples Epoxy resins A to F having the molecular weight distribution, epoxy equivalent and glass transition temperature shown in Table 1, and having the molecular weight distribution, phenolic hydroxyl group equivalent and glass transition temperature shown in Table 2 Phenol resin A ~
D, inorganic filler (maximum particle size less than 24 μm, average particle size 4
μm spherical silica), curing catalyst (2-phenylimidazole 2PZ or triphenylphosphine TPP),
Silane coupling agent (γ-glycidoxypropyltrimethoxysilane, KBM403: manufactured by Shin-Etsu Chemical Co., Ltd.) and a compound represented by the following formula (copolymer of aromatic polymer and organopolysiloxane, epoxy equivalent 291, siloxane content 31.2% by weight) were mixed as shown in Tables 3 to 5, and the resulting compound was uniformly melt-mixed with a hot two-roll mill to obtain an epoxy resin composition (Examples 1 to 10, Comparative Examples 1 to 5).
5) was produced. The mixing ratio of the epoxy resin, the phenolic resin, and the copolymer is such that the epoxy group / phenolic hydroxy group = 1/1 (molar ratio) and the polysiloxane content in the copolymer is 8 with respect to the entire resin component. It was adjusted to be% by weight.

In Comparative Examples 6 and 7, a liquid bisphenol A type epoxy resin (epoxy resin G, epoxy equivalent 179) was used as an epoxy resin, and in Comparative Example 6, DDM (4,4'-diaminodiphenylmethane, equivalent was used as a curing agent). 99) and Comparative Example 7 used 4-MTHPA (4-methyltetrahydrophthalic anhydride, equivalent 166). This was mixed in a formulation as shown in Table 5 (also blended so that the functional groups were equivalent), and the resulting epoxy resin composition was B-staged at about 60 ° C. After the glass transition temperature was reached, film forming and other operations were performed.

[0071]

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[0072]

[Table 1] A to D: Cresol novolak type epoxy resin E: Phenol novolak type epoxy resin F: Trishydroxyphenylmethane type epoxy resin Unit: 2 to 5 nuclei, 6 nuclei or more Weight% Mw: Weight average molecular weight, Mn: Number average molecular weight

[0073]

[Table 2] A to C: cresol novolak resin D: phenol novolak resin Unit: 2 to 4 nuclei, pentanuclear or more weight% Mw: weight average molecular weight, Mn: number average molecular weight

The following various tests (a) to (h) were performed on these epoxy resin compositions. Tables 3 to 5 show the results.
Shown in (A) Glass transition temperature (Tg) of uncured material Using 10 mg of uncured material, the maximum point of specific heat when the temperature was raised at 5 ° C./min by DCS was measured. (B) Film Handling Property A 10 mm × 50 mm × 0.1 mm strip-shaped uncured film is folded at 25 ° C. so that the short sides (10 mm) of the strips overlap, and the number of damaged films / the total number of films Was measured. (C) Glass transition temperature (Tg) of cured product 5 mm × 150 ° C., 50 kgf / cm ² , 3 minutes
A test piece of 5 mm × 15 mm was formed, and this was heated at 150 ° C.
After post-curing under the condition of 4 hours, TMA (The
rmal Mechanical Analysis)
And the value when the temperature was raised at 5 ° C. per minute was measured. (D) Moisture resistance 121 ° C./100%/2 atmRH of the semiconductor device of FIG.
It was left in the atmosphere for 24 hours and 48 hours, and the number of packages showing an abnormal value due to disconnection / the total number of packages was measured. (E) Water absorption rate 50 mm under conditions of 150 ° C., 50 kgf / cm ² , 3 minutes
A test piece of φ × 3 mm was molded and post-cured at 150 ° C. for 4 hours.
It was left in a 2 atmRH atmosphere for 24 hours, and the change in weight was measured. (F) Solder crack resistance after moisture absorption The semiconductor device of FIG. 1 was subjected to 121 ° C./100%/2 atmRH.
It was left in the atmosphere for 24 hours. This was immersed in a 240 ° C. solder bath for 10 seconds, and the number of crack generating packages / the total number of packages was measured. (G) Volatile Component of Uncured Material 5 g of the uncured material was heated at 180 ° C. for 1 hour, and the change in weight was measured. (H) Void amount of cured product For the semiconductor device of FIG. 1, using an ultrasonic flaw detector,
The void occupied area / total package area was measured.

Here, in FIG. 1, 1 is a BT base, 2
Is an Au terminal, 3 is a Cu wiring, 4 is an epoxy resin composition film, 5 is a solder bump, 6 is a Si chip, BT
On the base, a film (10 mm ×
10mm x 0.1mm) and temporarily press-fit.
After preheating at 0 ° C. for 10 seconds, a Si chip (10 mm × 10 mm ×
0.3 mm), 180 ° C, 10 kgf / cm ² ,
The semiconductor device was formed by heat molding under the condition of 10 seconds and post-curing the same at 150 ° C. for 1 hour.

[0076]

[Table 3]

[0077]

[Table 4]

[0078]

[Table 5]

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a semiconductor device used in an example and a comparative example.

[Explanation of symbols]

 Reference Signs List 1 BT substrate 2 Au terminal 3 Cu wiring 4 Epoxy resin composition film 5 Solder bump 6 Si chip

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court II (Reference) // C09D 163/00 (72) Inventor Hisashi Shimizu, Selangor, Malaysia, 40,000 Chararam, Hicom Industrial Estate, Jalan Serenda 26/17, Lot 50 Shin-Etsu Electronics Malaysia (72) Inventor Toshio Shiohara 1-10 Hitomi, Matsuida-cho, Usui-gun, Gunma Prefecture 10 Silicone Electronic Materials Technology Laboratory, Shin-Etsu Chemical Co., Ltd.

Claims (8)

[Claims] (A) The binuclear body is 10% by weight or less, 3 to 5%.
An epoxy resin having a total amount of cores of 50% by weight or more and a weight average molecular weight / number average molecular weight of 1.7 or less (B) an inorganic filler (C) a curing catalyst as an essential component, and is not cured. An epoxy resin composition, wherein the glass transition temperature of the product is less than 15 ° C. 2. The epoxy resin composition according to claim 1, wherein the curing catalyst of the component (C) is an imidazole. 3. The epoxy resin composition according to claim 1, which comprises a phenol resin as the component (D). 4. The epoxy resin composition according to claim 3, wherein the phenol resin as the component (D) has a glass transition temperature of less than 15 ° C. and does not contain a monomer. 5. The epoxy resin according to claim 1, comprising a copolymer obtained by reacting an aromatic polymer with an organopolysiloxane represented by the following composition formula (1). Composition. R _a R ′ _b SiO _{(4-ab) / 2} (1) (wherein R represents a hydrogen atom, an amino group, an epoxy group, a monovalent hydrocarbon group containing a hydroxy or carboxy group, or an alkoxy group) R ′ represents a substituted or unsubstituted monovalent hydrocarbon group, and a and b represent 0.001 ≦ a
It is a positive number satisfying ≦ 1, 0.9 ≦ b ≦ 2, and 1 ≦ a + b ≦ 3. The number of silicon atoms in one molecule is 2 to 100.
0, and the number of functional groups R directly bonded to silicon atoms in one molecule is one or more. ) 6. The epoxy resin composition according to claim 1, wherein a volatile component in the uncured product is 0.1% by weight or less. 7. A laminated film composed of two or more layers, wherein at least one layer is formed of the epoxy resin composition according to any one of claims 1 to 6 and has a thickness of 20 to 150 μm. 8. A semiconductor device in which the surface of a semiconductor element is sealed with a cured product of the laminated film according to claim 7.