JP2013007001A - Adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive composition in a paste state, which is excellent in viscosity stability and B-stage storage stability in an open system at room temperature and provides a cured product having no void.SOLUTION: The adhesive composition comprises the following components: an epoxy resin (A); an epoxy resin-curing accelerator (B); thermoplastic resin particles that are in a solid phase at 25°C; butyl carbitol acetate (D); an epoxy resin-curing agent (E); and an inorganic filler (F). The component (C) exists in the component (D) at room temperature without being dissolved or swelled.

Description

  The present invention relates to an adhesive composition suitable for adhering semiconductor elements, and in particular, includes a curing accelerator and thermoplastic resin particles that are not compatible with an epoxy resin solution phase, and improves the viscosity stability at room temperature. Since it is excellent, it is related with the adhesive composition which is favorable in workability | operativity and forms the stable B stage state on a board | substrate.

  Epoxy resins are used in various applications because of their excellent adhesiveness, heat resistance, and moisture resistance. In particular, liquid epoxy resins are widely used in the semiconductor field where miniaturization and high speed are being promoted, since they can be used for devices with complicated and fine designs. On the other hand, liquid epoxy resins are highly reactive and require careful attention during storage.

In order to mount the chip at an accurate position on the substrate, after applying a liquid epoxy resin on the substrate, it is heated at a relatively low temperature to lose fluidity, and is not completely cured, so-called B stage state In addition, the chip is mounted on this and then completely cured.
Examples of the method for applying the liquid epoxy resin on the substrate include a printing method and a dispensing method.

International Publication No. 2007/029504

In general, in order to adapt the viscosity of the adhesive composition to each use condition, a viscosity is often adjusted by adding a solvent to the composition. However, particularly in the printing method, since the work is performed in an open system for a long time, there is a concern that the printing workability may be deteriorated due to an increase in viscosity due to solvent evaporation.
Further, by adjusting the solvent content, the film thickness of the adhesive composition at the time of B-stage where the solvent is volatilized can be easily adjusted. However, there is also a problem that the solid thermoplastic resin swells or dissolves with the solvent when the solvent is added in a large amount, thereby increasing the viscosity.

  An object of the present invention is to provide an adhesive composition that is excellent in viscosity stability and B-stage storage stability in a room temperature open system in a paste state, and gives a cured product without voids.

As a result of intensive studies in order to achieve the above object, the present inventor has invented the following adhesive composition to achieve the object.
[1]
Component (A) Epoxy resin component (B) Epoxy resin curing accelerator component (C) Particle component of thermoplastic resin solid at 25 ° C. (D) Butyl carbitol acetate component (E) Epoxy resin curing agent, and component ( F) An adhesive composition comprising an inorganic filler, wherein component (C) remains in component (D) at room temperature without being dissolved or swollen.
[2]
The adhesive composition according to the above [1], wherein the component (D) is contained in an amount of 5 to 400 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (E).
[3]
The component (B) is contained in an amount of 0.1 to 10 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (E), according to the above [1] or [2] Adhesive composition.
[4]
Any one of the above [1] to [3], wherein the component (C) is contained in an amount of 5 to 50 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (E). The adhesive composition described in 1.
[5]
[1] The component (C) is particles of at least one thermoplastic resin selected from the group consisting of methacrylic resin, phenoxy resin, butadiene resin, polystyrene resin and copolymers thereof [1] ] Adhesive composition of any one of [4].
[6]
[1] to [5] above, wherein the component (C) has a polystyrene-equivalent number average molecular weight of 10,000 to 100,000 and a weight average molecular weight of 100,000 to 1,000,000. The adhesive composition according to any one of the above.
[7]
The adhesive composition according to any one of [1] to [6] above, wherein at least one of the component (A) and the component (E) includes a silicone-modified resin.
[8]
The said component (F) is contained in 10-200 mass parts with respect to a total of 100 mass parts of a component (A) and a component (E), Any one of said [1]-[7] characterized by the above-mentioned. Adhesive composition.
[9]
The adhesive composition according to any one of [1] to [8], wherein the viscosity of the adhesive composition measured at 25 ° C with an E-type viscometer is 0.1 to 500 Pa · s.
[10]
A semiconductor device using the adhesive composition according to any one of [1] to [9].

  The present invention provides an adhesive composition that is excellent in viscosity stability and B-stage storage stability in a room temperature open system in a paste state, and gives a cured product without voids.

  Each component contained in the adhesive composition of the present invention (also referred to as “the composition of the present invention”) will be described in detail below.

<Component (A): Epoxy resin>
In the present invention, examples of the (A) epoxy resin include novolak type, bisphenol type, biphenyl type, phenol aralkyl type, biphenyl aralkyl type, triphenolalkane type, dicyclopentadiene type, naphthalene type, amino group-containing type, which will be described later. Examples include silicone-modified epoxy resins and mixtures thereof. Of these, bisphenol A type, bisphenol F type, novolac type epoxy resin and silicone-modified epoxy resin are preferable.

  The silicone-modified epoxy resin is a copolymer obtained by reacting an alkenyl group-containing epoxy resin with an organohydrogenpolysiloxane. Examples of the alkenyl group-containing epoxy resin include those represented by the following formulas (1) to (4).

In the above formulas (1) to (4), R ¹ is a glycidyl group represented by the following formula:

  X is a hydrogen atom or a bromine atom, and n is an integer of 0 or more, preferably 0 to 50, more preferably an integer of 1 to 20. m is an integer of 1 or more, preferably an integer of 1 to 5, more preferably 0 or 1.

  The organohydrogenpolysiloxane to be reacted with the alkenyl group-containing epoxy resin is an organohydrogen having at least 2, preferably 2, hydrogen atoms bonded to silicon atoms (hydrosilyl group represented by SiH) in one molecule. Polysiloxane, which is a compound represented by the following average composition formula (5).

In the above formula (5), R ² is a substituted or unsubstituted monovalent hydrocarbon group, hydroxy group, alkoxy group, or alkenyloxy group.
The monovalent hydrocarbon group is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms. For example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, Alkyl groups such as pentyl group, neopentyl group, hexyl group, cyclohexyl group, octyl group, decyl group, alkenyl group such as vinyl group, allyl group, propenyl group, butenyl group, aryl group such as phenyl group, tolyl group, benzyl group And an aralkyl group such as a phenylethyl group, and a halogen-substituted monovalent hydrocarbon group in which part or all of the hydrogen atoms of these hydrocarbon groups are substituted with a halogen atom.
In the formula (5), a and b are numbers satisfying 0.001 ≦ a ≦ 1, 1 ≦ b ≦ 3, 1 ≦ a + b <4, preferably 0.01 ≦ a ≦ 0.1, 1. 8 ≦ b ≦ 2, 1.85 ≦ a + b ≦ 2.1. The organohydrogenpolysiloxane desirably has 1 to 1000, preferably 2 to 400, more preferably 5 to 200 silicon atoms in one molecule. Examples of the organohydrogenpolysiloxane include molecular chain both ends diorganohydrogensiloxy group blocked diorganopolysiloxane, molecular chain both ends diorganohydrogensiloxy group blocked diorganosiloxane / organohydrogensiloxane copolymer, etc. In particular, the compound represented by the formula (6) is exemplified.

(R ² is as described above, preferably a methyl group or a phenyl group. P is an integer of 0 to 1000, preferably an integer of 3 to 400, and q is an integer of 0 to 20, preferably 0 to 0. And an integer satisfying 1 <p + q <1000, preferably 2 <p + q <400, and more preferably 5 <p + q <200.)

  More specific examples of such organohydrogenpolysiloxanes include the following.

  The organohydrogenpolysiloxane has a molecular weight of 100 to 100,000, preferably 500 to 20,000. When the molecular weight of the organohydrogenpolysiloxane is within the above range, the structure or molecular weight of the alkenyl group-containing epoxy resin to be reacted with the organohydrogenpolysiloxane allows a uniform structure in which the organohydrogenpolysiloxane is uniformly dispersed in the matrix, Alternatively, a sea-island structure appears in which organohydrogenpolysiloxane forms fine layer separation in the matrix.

  When the molecular weight of the organohydrogenpolysiloxane is relatively small, particularly 100 to 10,000, a uniform structure is formed. When the molecular weight of the organohydrogenpolysiloxane is relatively large, particularly 10,000 to 100,000. If so, a sea-island structure is formed. Either a uniform structure or a sea-island structure may be selected according to the application. If the molecular weight of the organohydrogenpolysiloxane is less than 100, the cured product is rigid and brittle. On the other hand, if the molecular weight is greater than 100,000, the sea-island structure is increased and local stress is generated, which is not preferable.

  A known method can be used for reacting the alkenyl group-containing epoxy resin with the organohydrogenpolysiloxane. For example, an addition reaction between the alkenyl group-containing epoxy resin and the organohydrogenpolysiloxane in the presence of a platinum-based catalyst. It is attached to. The organohydrogenpolysiloxane is preferably copolymerized in such an amount that the SiH group of the organohydrogenpolysiloxane is 0.1 to 1 mol with respect to 1 mol of the alkenyl group of the alkenyl group-containing epoxy resin.

<Component (B): Curing accelerator>
(B) As a hardening accelerator, basic organic compounds, such as organic phosphorus, an imidazole, a tertiary amine, are mentioned, for example. Examples of organic phosphorus include triphenylphosphine, tributylphosphine, tri (p-toluyl) phosphine, tri (p-methoxyphenyl) phosphine, tri (p-ethoxyphenyl) phosphine, triphenylphosphine / triphenylborate derivatives, tetra Examples thereof include phenylphosphine and tetraphenylborate derivatives. Examples of imidazole include 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxy. Examples include methylimidazole and 2-phenyl-4,5-dihydroxymethylimidazole. Examples of the tertiary amine include triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine, 1,8-diazabicyclo (5,4,0) undecene-7, and the like.

  Among these, a tetraphenylphosphine / tetraphenylborate derivative represented by the following formula (7) or a methylolimidazole derivative represented by the following formula (8) is preferable, and more preferably (E) curing agent described later. These phenol resins or silicone-modified phenol resins are used in combination.

However, R ^{B1 to} R ^B8 are each independently a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, or a halogen atom.

However, R ^B9 is a methyl group or a methylol group, and R ¹⁰ is a hydrocarbon group having 1 to 10 carbon atoms.

  The addition amount of the (B) curing accelerator is desirably 0.1 to 10 parts by mass, particularly 0 with respect to 100 parts by mass of the total of (A) the epoxy resin and (E) the epoxy resin curing agent. Desirably 2 to 5 parts by mass. When the curing accelerator is less than the lower limit, the adhesive composition may be insufficiently cured, and when it is higher than the upper limit, the storage stability of the adhesive composition or the stability of the B stage state May cause trouble.

<Component (C): Thermoplastic resin particles>
The composition of the present invention comprises (C) thermoplastic resin particles that are solid at 25 ° C. As will be described later, the thermoplastic resin is not dissolved or swelled in (D) butyl carbitol acetate during storage or at the temperature applied to the substrate, and the epoxy resin (A) dissolved in butyl carbitol acetate (A) ) Exists in a different phase.

  The thermoplastic resin may be a known resin, for example, AAS resin, AES resin, AS resin, ABS resin, MBS resin, vinyl chloride resin, vinyl acetate resin, methacrylic resin, phenoxy resin, polybutadiene resin, various kinds of fluorine. Resin, various silicone resins, polyacetal, various polyamides, polyamideimide, polyimide, polyetherimide, polyetheretherketone, polyethylene, polyethylene oxide, polyethylene terephthalate, polycarbonate, polystyrene, polysulfone, polyethersulfone, polyvinyl alcohol, polyvinyl Ether, polyvinyl butyral, polyvinyl formal, poniphenylene ether, polyphenylene sulfide, polybutylene terephthalate, polypropylene, poly Chirupenten, and the like. Among these, methacrylic resin, phenoxy resin, butadiene resin, polystyrene resin or a copolymer thereof is desirable. Moreover, the core-shell structure in which resin differs in the inner core (core) part and outer skin (shell) part of a thermoplastic resin particle may be sufficient. In that case, it is desirable that the core is rubber particles made of silicone resin, fluororesin, butadiene resin or the like, and the shell is the above-mentioned various thermoplastic resins made of linear molecular chains.

  (C) The thermoplastic resin particles may be substantially spherical, cylindrical or prismatic, indefinite, crushed, and flake-like, and are preferably substantially spherical and indeterminate with no sharp corners for die bonding agents. .

(C) The particle size of the thermoplastic resin particles is appropriately selected depending on the application, but usually the maximum particle size is preferably 10 μm or less, particularly preferably 5 μm or less, and the average particle size is 0.1 to 5 μm, In particular, the thickness is desirably 0.1 to 2 μm. If the maximum particle size is not more than the above upper limit value or the average particle size is 5 μm or less, the thermoplastic resin particles sufficiently swell and dissolve in the B-stage stage or the curing stage, so the characteristics of the composition after curing There is no fear of damage. On the other hand, if the average particle size is equal to or greater than the lower limit, the viscosity of the composition becomes appropriate, and there is no possibility that workability will be significantly deteriorated. The particle size can be measured, for example, as cumulative weight average particle D ₅₀ (or median diameter) in particle size distribution measurement by a laser light diffraction method, or by electron microscope observation.

  The maximum particle size of the thermoplastic resin particles (C) is desirably 20% or less, particularly 10% or less of the thickness of the die bond agent applied on the substrate, and the average particle size is 10% or less of the thickness. In particular, it is desirable to be 5% or less. When the maximum particle size is not more than the above upper limit value or the average particle size is not more than the above upper limit value, the thermoplastic resin particles are sufficiently swollen or dissolved in the B-stage stage or the curing stage. There is no possibility of causing defects such as defects in appearance and damage or leakage of the chip surface.

  (C) The thermoplastic resin particles may have a crosslinked structure. However, since it is considered preferable to form a structure in which the thermoplastic resin (C) is uniformly dispersed in the epoxy resin network structure, it is preferable that the degree of cross-linking is low, and it is composed of linear molecular chains without cross-linking. Is more preferable.

  (C) The molecular weight of the thermoplastic resin particles is appropriately selected depending on the type of resin. Typically, the polystyrene-equivalent number average molecular weight is 1,000 to 10,000,000, preferably 10,000 to 100,000, and the weight average molecular weight is 10,000 to 100,000,000, preferably 100,000. 000 to 1,000,000. If the number average molecular weight is not less than the above lower limit value or the weight average molecular weight is not less than the above lower limit value, the swelling temperature is not too low and the temperature is appropriate, and the B stage does not appear at an early stage. Becomes stable. Further, the hardness of the B stage state can be sufficiently obtained, and there is no possibility of occurrence of defects such as voids, outflow, or die shift particularly in die bond material applications. On the other hand, if the number average molecular weight is not more than the above upper limit value or the weight average molecular weight is not more than the above upper limit value, the swelling temperature does not become too high, and there is a sufficient difference from the appearance temperature of the C stage, so the B stage state is stable. become. Further, there is a possibility that a part of the particle thermoplastic resin inhibits the formation of the epoxy resin network structure after the B-stage or the C-stage. The average molecular weight can be determined, for example, as a number average value or a weight average value in terms of polystyrene in gel permeation chromatography (GPC) analysis using toluene, THF or the like as a developing solvent.

  (C) The content of the thermoplastic resin particles is preferably 5 parts by mass to 50 parts by mass with respect to 100 parts by mass in total of the component (A) and the component (E) in order to obtain a stable B-stage state. Parts, more preferably 10 to 30 parts by mass. If the content is equal to or greater than the lower limit, sufficient B-stage hardness is obtained, so that the resin does not flow out of the semiconductor chip and there is no fear of generating fillets. On the other hand, if the content is less than or equal to the above upper limit value, the B stage state does not become too hard, and there is no possibility of occurrence of defects such as insufficient adhesion.

<Component (D): Butyl carbitol acetate>
Butyl carbitol acetate is an important ingredient that characterizes the present invention.
First, it is important that the thermoplastic resin particles of the component (C) remain in the butyl carbitol acetate of the component (D) at room temperature without being dissolved or swollen in the composition of the present invention. Here, in the present invention, “does not dissolve” means that the solubility is less than 20% by mass under the conditions of room temperature (25 ° C.) and pressure of 1 atm. That is, it may not be in a state where 100% by mass is not dissolved, but may be substantially dissolved up to about 20% by mass, that is, as long as it is not dissolved in about 80% by mass or more. Further, “swelling” means that the organic solvent enters the matrix of the thermoplastic resin particles of the component (C) and the volume of the resin particles increases. However, in the present invention, “does not swell” does not mean that the volume of the resin particles does not change at all, and the organic solvent penetrates into the matrix to increase the volume of the resin particles. It is meant that the degree of increase in the viscosity of the composition due to the apparent decrease in the proportion of organic solvent is below a certain level. Specifically, as will be described later, it means that the rate of increase in viscosity of the composition after 1 hour at 25 ° C./24 hours is less than 1.5 times, more preferably 1.2 times or less. .
When the (C) thermoplastic resin particles are dissolved or swelled in (D) butyl carbitol acetate, the viscosity of the entire composition becomes high and the viscosity is not suitable for printing. Further, even when the ink gradually dissolves or swells, the viscosity gradually increases, so that printing stability is impaired.

Further, the (B) epoxy resin curing accelerator and the inorganic filler (F) described later remain in the butyl carbitol acetate of the component (D) at room temperature without being dissolved or swollen in the same manner as the component (C). It is preferable that it is in the state.
When (B) epoxy resin curing accelerator is dissolved in (D) butyl carbitol acetate, (B) epoxy resin curing accelerator is dispersed in (A) epoxy resin and (E) epoxy resin curing agent at the molecular level. The reactivity increases at room temperature, and the storage stability at room temperature may deteriorate.
In addition, the (F) inorganic filler generally does not dissolve or swell in the organic solvent including the component (D).

  Furthermore, it is preferable that the (A) epoxy resin and the (E) epoxy resin curing agent described below are dissolved in (D) butyl carbitol acetate. Here, the “dissolving” state means that the solubility is 20% by mass or more under the conditions of room temperature (25 ° C.) and pressure of 1 atm.

The dissolved state can be confirmed by separating the solid content from the composition by an ordinary analysis method. For example, after identifying the solvent by GC / MS or the like, if necessary, the composition is further diluted with the solvent, and the solid content is separated by centrifugation or filtration. Component (F) can be identified as a residue after burning the solid. Components (B) and (C) are separated from each other using a difference in solubility using an appropriate strong solvent such as chloroform, and then subjected to structural analysis, for example, IR analysis. Can be confirmed.
Moreover, the swelling state can be confirmed by the degree of increase in the viscosity of the composition as described above.

  Moreover, the butyl carbitol acetate of a component (D) satisfy | fills evaporating after making B stage by heating at 60-200 degreeC for 3 hours-1 minute. This state can be easily confirmed using a hot plate or the like.

  Content of a component (D) butyl carbitol acetate is suitably adjusted with the viscosity in 25 degreeC of adhesive composition. The viscosity is selected in a suitable range depending on the application method of the adhesive composition. For example, in the case of a screen printing method on a substrate, 5 to 500 Pa · s is preferable, and 10 to 200 Pa · s is more preferable. In the case of the stencil printing method on the substrate, the pressure is preferably 10 to 1000 Pa · s, more preferably 20 to 300 Pa · s. Here, if the viscosity is not more than the above upper limit value, the content of butyl carbitol acetate is not too small, and workability applied to a substrate or the like is good. Further, since it is not necessary to increase the pressure of the squeegee at the time of printing, there is a possibility that the mask wear is suppressed and the life of the mask is shortened for a long time. On the other hand, if the viscosity is equal to or higher than the lower limit, the content of butyl carbitol acetate is not too much, and there is no possibility that the inorganic filler (F) described later settles during long-term storage.

<Component (E): Epoxy resin curing agent>
A well-known thing can be used as an epoxy resin hardening | curing agent, For example, a phenol resin (including the silicone modified phenol resin mentioned later), an acid anhydride, and amines are mentioned. Of these, phenol resins and silicone-modified phenol resins are preferred in consideration of the balance between curability and stability in the B-stage state. Examples of the phenol resin include aralkyl type, novolak type, bisphenol type, trishydroxyphenylmethane type, naphthalene type, cyclopentadiene type, phenol aralkyl type, etc., and these may be used alone or in combination of two or more. good. Of these, aralkyl type, novolak type, and bisphenol type are preferable.

  Examples of the silicone-modified phenol resin include a copolymer obtained by reacting the organohydrogenpolysiloxane represented by the above formula (6) with the following alkenyl group-containing phenol resin. The reaction may be performed using a known method. For example, an alkenyl group-containing phenol resin and an organopolysiloxane are subjected to an addition reaction in the presence of a platinum-based catalyst. The organopolysiloxane is preferably copolymerized in such an amount that the SiH group of the organopolysiloxane is 0.1 to 1 mol with respect to 1 mol of the alkenyl group of the alkenyl group-containing phenol resin.

  Examples of the alkenyl group-containing phenol resin include those represented by the following formulas (9) to (13).

(However, X, n, and m are as described above. R ³ is a hydrogen atom or a methyl group.)

  The compounding ratio of the component (A) and the component (E) is such that the group having reactivity with the epoxy group in the component (E) is 0.8 to 1.25 with respect to 1 equivalent of the epoxy group in the component (A). It is desirable that it is equivalent, and it is particularly desirable that it is 0.9 to 1.1 equivalent. If the equivalence ratio is within this range, the reaction proceeds sufficiently, and there is no possibility that the performance of the cured product and further the performance of the semiconductor device using the cured product will be hindered.

  In the adhesive composition of the present invention, it is preferable that at least one of the component (A) and the component (E) is silicone-modified. When component (E) is not silicone-modified, component (A) is a silicone-modified epoxy resin. When the adhesive resin composition contains a silicone chain, a cured product having low elasticity and excellent heat cycle resistance can be provided.

<Component (F): Inorganic filler>
Examples of the inorganic filler include fused silica, crystalline silica, alumina, titanium oxide, silica titania, boron nitride, aluminum nitride, silicon nitride, magnesia, magnesium silicate, talc, mica, and the like. It can be used alone or in combination of two or more. In particular, silica, alumina, and talc are preferably used alone or in combination of two or more.

  The inorganic filler is preferably blended in an amount of 10 to 200 parts by weight, more preferably 20 to 180 parts by weight, and particularly preferably 30 to 150 parts by weight with respect to a total of 100 parts by weight of the component (A) and the component (E). .

  When the composition of the present invention is used as a die bond agent, the maximum particle size of the inorganic filler is desirably 20% or less, particularly 10% or less of the thickness of the die bond agent applied on the wafer, and the average particle size is It is desirable that the thickness is 10% or less, particularly 5% or less. If the maximum particle size is less than or equal to the above upper limit value or the average particle size is less than or equal to the above upper limit value, the chip, the substrate, the gold wiring, etc. may be damaged, or locally at the boundary between the inorganic filler and other parts There is no fear of impairing the function of the semiconductor device.

  It is preferable to use the inorganic filler that has been surface-treated with a silane coupling agent in advance. More preferably, the epoxy resin of component (A) and the filler surface-treated with a coupling agent are preliminarily decompressed and kneaded. As a result, the interface between the filler surface and the epoxy resin can be in a well-wet state, and the moisture resistance reliability is significantly improved.

  Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, γ -Methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, N-β (amino Ethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ- A Nopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, bis (triethoxypropyl) tetrasulfide, γ-isocyanatopropyltriethoxysilane Etc. These can be used singly or in combination of two or more. Among these, it is preferable to use γ-glycidoxypropyltrimethoxysilane.

  In addition to the above components, additives such as silane coupling agents, flame retardants, ion trapping agents, waxes, colorants, adhesion aids, etc., do not impair the purpose of the present invention, depending on the application. Can be added in amounts.

  Examples of the silane coupling agent as the additive include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, and p-styryltrimethoxy. Silane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, N- β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane , Γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, bis (triethoxypropyl) tetrasulfide, γ-isocyanate Examples thereof include propyltriethoxysilane. These can be used singly or in combination of two or more. Among these, it is preferable to use γ-glycidoxypropyltrimethoxysilane. When using the said coupling agent, the usage-amount is 0.1-5.0 mass parts normally with respect to a total of 100 mass parts of the said component (A) and (E), Preferably 0.3- 3.0 parts by mass.

<Preparation of composition>
The composition of this invention can be prepared using a well-known mixing method, for example, a mixer, a roll, etc.

The adhesive composition of the present invention preferably has a thickness increase of 1 mm and a viscosity increase rate after 25 ° C./24 hours of less than 1.5 times. If the rate of increase in viscosity is less than 1.5 times, the increase in resin viscosity during printing is extremely low, so that continuous printing stability over time is excellent.
The viscosity increase rate is calculated as follows. First, the viscosity of the adhesive composition is measured at 25 ° C. using an E-type viscometer according to JIS Z-8803, and this is defined as the initial viscosity. And the viscosity after extending an adhesive composition to 1 mm thickness and hold | maintaining 25 degreeC / 24 hours is measured. And a viscosity increase rate is calculated | required by the following formula.
Viscosity increase rate = (25 ° C./viscosity after 24 hours) / (initial viscosity)
The adhesive composition of the present invention preferably has a viscosity of 0.1 to 500 Pa · s measured at 25 ° C. with an E-type viscometer. If the viscosity at 25 ° C. is within the above range, stable printing is possible.

  The adhesive composition of the present invention is suitable for bonding semiconductor elements.

  EXAMPLES The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

  The following components were mixed in each mass part shown in Table 1 with a planetary mixer at 25 ° C., passed through three rolls at 25 ° C., and then mixed at 25 ° C. with a planetary mixer. Compositions 1 to 3 and Comparative Examples 1 to 4 were prepared. Each composition was subjected to the following tests (a) to (c), and the results shown in Table 1 were obtained.

<Resin used>
(A) Epoxy resin Epoxy resin a (bisphenol A type epoxy resin, equivalent weight 180, RE310S manufactured by Nippon Kayaku Co., Ltd.)
(B) Epoxy resin curing accelerator Curing accelerator b (tetraphenylphosphine / tetraphenylborate, TPP-K manufactured by Hokuko Chemical)
(C) Thermoplastic resin particles Particulate thermoplastic resin c (polymethyl methacrylate, number average molecular weight 50,000, weight average molecular weight 150,000, average particle diameter 1 μm, maximum particle diameter 3 μm)
(D) Solvent Solvent d1 (Butyl carbitol acetate)
Solvent d2 (carbitol acetate)
Solvent d3 (isophorone)
(E) Epoxy resin curing agent Silicone-modified curing agent e (Synthesis Example 1)
(F) Inorganic filler Silica f (spherical fused silica, average particle size 0.6 μm, maximum particle size 3 μm, SE2030 manufactured by Admatex Corporation)
Other additives Silane coupling agent g (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.)

(Synthesis Example 1) Synthesis of silicone-modified curing agent g 30.8 g (0.10 mol) of phenol resin of formula (14) and toluene 123 were added to a flask equipped with a stirring blade, a dropping funnel, a thermometer, an ester adapter and a reflux tube. .2 g was added and azeotropic dehydration was performed at 130 ° C./2 hours. This was cooled to 100 ° C., 0.5 g of a catalyst (CAT-PL-50T manufactured by Shin-Etsu Chemical Co., Ltd.) was dropped, and 36.3 g (0.05 mol) of the organopolysiloxane of the formula (15) and toluene 145. 2 g of the mixture was dropped in about 30 minutes and further aged at 100 ° C./6 hours. From this, toluene was removed to obtain a brown transparent liquid (η = 20 Pa · s / 25 ° C., phenol equivalent 340, organopolysiloxane content 54.1 parts by mass). This was designated silicone-modified curing agent g.

<Test method>
(A) for the initial viscosity each composition, according to JIS Z-8803, E-type viscometer (HBDV-III, manufactured by Brookfield) using the measured temperature 25 ° C., shear rate 2.00 ^{(sec -1)} The viscosity at 2 minutes after the start of rotation was measured.
(B) Viscosity increase rate (viscosity increase rate after 25 ° C./24 hours at 1 mm thickness)
Each adhesive composition was stretched to a thickness of 1 mm, the viscosity at 25 ° C./24 hours was measured in the same manner as in (a), and the rate of increase in viscosity was calculated according to the following formula.
Viscosity increase rate = {(25 ° C./viscosity after 24 hours) − (initial viscosity)} / (initial viscosity)
(C) Printing stability For each resin composition, a stencil mask (manufactured by SUS, 80 μm thickness, opening size: 10 mm × 10 mm) and squeegee on a BT substrate (200 μm thickness, 35 mm × 35 mm) coated with AUS308 (20 μm thickness). (SUS, 500 μm thickness, angle 60 °), printing is performed every hour under the conditions of a speed of 10 mm / second and a pressure of 3 kg (comparative example 4 is 6 kg), and immediately after printing, 120 ° C./10 minutes B stage.
Thereafter, the resin thickness after the B-stage in the initial printing after 6, 12, 18, and 24 hours was measured.

  From Table 1, in the resin composition of Comparative Example 1 using carbitol acetate as a solvent, the thermoplastic resin gradually swells with carbitol acetate, and the viscosity increases. This resulted in poor printing stability. In the resin composition of Comparative Example 2 using isophorone as a solvent, isophorone gradually volatilizes and increases in viscosity. This resulted in poor printing stability. In Comparative Examples 3 and 4 in which no solvent was added, the viscosity was high and the printing thickness was not stable when the printing pressure was 3 kg. Further, when the printing pressure was increased to 6 kg, stable printability was exhibited, but the thickness could not be controlled. There is also concern about shortening the life of printing plates. On the other hand, it was confirmed that the resin composition of the present invention maintained a stable viscosity for a long time without attacking the thermoplastic resin and because the volatilization rate of butyl carbitol acetate at room temperature was extremely slow.

  The resin composition of the present invention is stable in the A-stage state in an open room temperature system and does not invade the thermoplastic resin that is a B-stage material, and can realize stable printability for a long time. Also, the viscosity can be easily adjusted by increasing / decreasing the amount of butyl carbitol acetate added, and the thickness of the B stage after the butyl carbitol acetate volatilizes can be easily determined. As an adhesive composition, it is a material that can meet detailed requirements.

Claims (10)

Component (A) Epoxy resin component (B) Epoxy resin curing accelerator component (C) Particle component of thermoplastic resin solid at 25 ° C. (D) Butyl carbitol acetate component (E) Epoxy resin curing agent, and component ( F) An adhesive composition comprising an inorganic filler, wherein the component (C) remains in the component (D) at room temperature without being dissolved or swollen.   The adhesive composition according to claim 1, wherein the component (D) is contained in an amount of 5 to 400 parts by mass with respect to 100 parts by mass in total of the component (A) and the component (E).   The adhesive composition according to claim 1 or 2, wherein the component (B) is contained in an amount of 0.1 to 10 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (E). object.   The said component (C) is 5-50 mass parts is contained with respect to a total of 100 mass parts of the said component (A) and a component (E), The any one of Claims 1-3 characterized by the above-mentioned. Adhesive composition.   The component (C) is particles of at least one thermoplastic resin selected from the group consisting of methacrylic resin, phenoxy resin, butadiene resin, polystyrene resin and copolymers thereof. The adhesive composition of any one of -4.   The polystyrene-reduced number average molecular weight of the component (C) is 10,000 to 100,000, and the weight average molecular weight is 100,000 to 1,000,000. The adhesive composition according to Item.   The adhesive composition according to any one of claims 1 to 6, wherein at least one of the component (A) and the component (E) contains a silicone-modified resin.   The said component (F) is contained in 10-200 mass parts with respect to a total of 100 mass parts of a component (A) and a component (E), The adhesive agent of any one of Claims 1-7 characterized by the above-mentioned. Composition.   The adhesive composition according to any one of claims 1 to 8, wherein the viscosity of the adhesive composition measured at 25 ° C with an E-type viscometer is 0.1 to 500 Pa · s.   The semiconductor device using the adhesive composition of any one of Claims 1-9.