JP4059244B2 - Epoxy resin composition, prepreg, laminated board, printed wiring board - Google Patents

Description

  The present invention relates to an epoxy resin composition, a prepreg using the epoxy resin composition, a laminate using the prepreg, and a printed wiring board using the laminate.

  Thermosetting resins typified by epoxy resins are widely used as printed wiring board materials and semiconductor sealing materials because of their excellent adhesion, electrical insulation, chemical resistance, and the like. A printed wiring board is manufactured by impregnating a base material such as a glass cloth with a varnish containing the thermosetting resin described above, producing a prepreg, laminating a predetermined number of the prepregs, and further heating and pressing a metal foil laminated. It can be manufactured by forming a laminate by forming a conductor pattern on the surface of the metal foil and forming a circuit.

  In recent years, the density of printed wiring boards has been rapidly increasing, and in order to produce printed wiring boards with fine conductor patterns formed at high density with good yield, it is desirable that the laminated board has a small dimensional change. Therefore, it is required to keep the linear expansion coefficient (thermal expansion coefficient) in the plane direction of the laminate small. Furthermore, when conducting conduction between layers of printed wiring boards with through-holes, etc., if the linear expansion coefficient in the thickness direction is large, a conduction failure may occur, so it is also required to keep the linear expansion coefficient in the thickness direction small. Yes.

  On the other hand, an epoxy resin composition using fine particles having a core-shell structure is known in order to improve impact resistance and heat resistance of a laminated board and a flexible printed wiring board (see, for example, Patent Documents 1 to 3).

  And conventionally, in order to keep the linear expansion coefficient of the laminate small, core-shell rubber particles coated with a shell layer compatible with fine particles having the above-described core-shell structure or an epoxy resin (for example, Patent Documents 4 to 6) It is known that fine particles such as fine particles having rubber elasticity that are incompatible with the epoxy resin (see, for example, Patent Document 7) are contained in a varnish containing an epoxy resin.

However, although these methods can reduce the linear expansion coefficient in the plane direction, the reduction of the linear expansion coefficient in the thickness direction has not yet reached a satisfactory level, and the linear expansion coefficient in the thickness direction has been increased. It is desired to keep it small.
JP 2001-123044 A JP 2002-338875 A JP 2003-213082 A Japanese Patent Laid-Open No. 8-48001 JP 2000-158589 A JP 20003-246849 A Japanese Patent No. 3173332

  Therefore, the present invention is based on the background as described above, an epoxy resin composition improved so that the linear expansion coefficient in the plane direction of the laminate is small and the linear expansion coefficient in the thickness direction is small, and the epoxy resin composition An object of the present invention is to provide a prepreg using an object, a laminate using the prepreg, and a printed wiring board using the laminate.

The epoxy resin composition of the present invention is a resin composition containing an epoxy resin, a curing agent and a flexible component, as a solution to the above-mentioned problems, and the curing agent is a phenol novolak resin. And, as a flexible component, containing fine particles composed of a resin having a core-shell structure and a shell portion containing a functional group that reacts with an epoxy resin , wherein the functional group is at least one of a hydroxyl group, a carboxyl group, and an epoxy group characterized by any functional group der Rukoto.

The epoxy resin composition of the present invention, the second, in the above-described epoxy resin composition, the core portion of the core-shell structure is an acrylic resin, a third, core portion of the core-shell structure is silicone resin It is characterized by being.

The epoxy resin composition of the present invention, in the fourth, in the above-described epoxy resin composition, characterized by containing a rubber particle as the elastic component, the fifth, characterized in that it contains an inorganic filler And

Further, the prepreg of the present invention, the sixth one of the epoxy resin composition of the impregnating the substrate, wherein the heated drying and is semi-cured.

A seventh aspect of the laminated sheet of the present invention is characterized in that a predetermined number of the above prepregs are laminated and a metal foil laminated and formed is heated and pressed.

An eighth aspect of the printed wiring board of the present invention is characterized in that a conductor pattern is formed on the surface of the metal foil.

In the epoxy resin composition of the first invention, the curing agent is a phenol novolak resin, and the flexible component is composed of a resin having a core-shell structure and a shell portion containing a functional group that reacts with the epoxy resin. A laminate produced from a prepreg using this epoxy resin composition contains fine particles, and the functional group is at least one of a hydroxyl group, a carboxyl group, and an epoxy group. The linear expansion coefficient in the direction can be reduced, the dimensional change is reduced, and a printed wiring board using the laminated board can be manufactured with a high yield.

In the said 2nd invention, it can be set as the laminated board excellent in heat resistance because the core part of a core-shell structure is an acrylic resin.

In the said 3rd invention, when the core part of a core-shell structure is a silicon resin, it can be set as the laminated board excellent in heat resistance and an electrical property.

In the fourth aspect of the invention, by containing rubber fine particles as a flexible component, in addition to the above effects, the linear expansion coefficient in the plane direction of the laminate can be further reduced.

In the said 5th invention, in addition to said effect by containing an inorganic filler, the linear expansion coefficient of the thickness direction of a laminated board can be made smaller.

Furthermore, in the sixth invention, a laminate produced from this prepreg is obtained by impregnating a base material with any of the epoxy resin compositions described above, drying by heating, and semi-curing the laminate. The linear expansion coefficient in the direction can be reduced, the dimensional change is reduced, and a printed wiring board using the laminated board can be manufactured with a high yield.

In the seventh aspect of the invention, a predetermined number of the above prepregs are laminated, and a metal foil is laminated and formed by heating and pressurizing, so that the line in the surface direction and the thickness direction of the laminated plate is obtained. An expansion coefficient can be made small, a dimensional change becomes small, and the printed wiring board using this laminated board can be manufactured with a sufficient yield.

And in said 8th invention, by producing a conductor pattern on the surface of said metal foil, the linear expansion coefficient of the surface direction and thickness direction of a laminated board can be made small, and a dimensional change becomes small and this. A printed wiring board using a laminate can be manufactured with high yield.

  The present invention has the above-described features, and the best mode for carrying out the invention will be described below.

The epoxy resin composition of the present invention is a resin composition containing an epoxy resin, a curing agent and a flexible component, and the curing agent is a phenol novolac resin, and has a core-shell structure as a flexible component and a shell portion. Contains fine particles composed of a resin containing a functional group that reacts with an epoxy resin.

  Any epoxy resin can be used without particular limitation as long as it has two or more epoxy groups in one molecule. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, alicyclic epoxy resin, polyfunctional phenol diglycidyl ether compound, polyfunctional alcohol diglycidyl ether compound, phenol Phenol novolak type epoxy resins, cresol novolak type epoxy resins, bisphenol A novolak type epoxy resins which are glycidyl etherified products of polycondensates of aldehydes and formaldehyde and halogenated epoxy resins for flame retardancy, and the like. These may be used alone or in combination.

  The most characteristic feature of the present invention is the use of a phenol novolak resin as a curing agent. Specific examples of the phenol novolak resin include a phenol novolak resin, a cresol novolak resin, a bisphenol novolak A resin, a biphenyl novolak resin, and a naphthol aralkyl resin, and these may be used alone or in combination. By using these curing agents, the coefficient of linear expansion in the surface direction and thickness direction of a laminate produced from a prepreg using an epoxy resin composition can be kept low compared to amine-based curing agents such as dicyandiamide. It can be done.

  The blending amount of the curing agent is preferably adjusted so that the equivalent ratio with respect to the epoxy resin is 0.5 to 1.5, particularly 0.8 to 1.2. When the equivalent ratio of the curing agent to the epoxy resin is less than 0.5, the epoxy resin composition may be insufficiently cured, which is not preferable. If it exceeds 1.5, the curing agent remains unreacted, and the resulting laminated board may be deteriorated in performance such as heat resistance and impact resistance.

  The epoxy resin composition of the present invention may further use a curing accelerator in order to further accelerate the curing reaction. This is not particularly limited as long as it accelerates the curing reaction of a normal epoxy resin. For example, imidazoles such as 2-methylimidazole and 2-phenylimidazole, and tertiary such as triethylenediamine. Organic phosphines such as amines and triphenylphosphine can be used. These may be used alone or in combination. The blending amount of the curing accelerator is preferably 0.1 to 5.0% by weight based on all resin components (epoxy resin and curing agent).

The flexible component of the present invention contains fine particles composed of a resin having a core-shell structure and a shell portion containing a functional group that reacts with an epoxy resin. In the fine particles having this core-shell structure, the shell portion Examples of the resin constituting PMMA include PMMA (polymethyl methacrylate) and polystyrene. And since the functional group which reacts with an epoxy resin is introduce | transduced into these resin, and this functional group couple | bonds with an epoxy resin chemically and is compatible, the thermal motion of a flexible component is suppressed by an epoxy resin. Therefore, the linear expansion coefficient in the thickness direction of the laminate obtained by using such an epoxy resin composition can be reduced. Examples of such functional groups, human Dorokishiru group, a carboxyl group, an epoxy group, and at least one functional group among these that has been introduced into the resin constituting the shell portion.

  Moreover, as what constitutes a core part in the microparticles | fine-particles which have the above core shell structure, a silicon resin, an acrylic resin, a butadiene type rubber, an isoprene type rubber etc. are mentioned, for example. Among these, silicon resin and acrylic resin are preferable in consideration of heat resistance, and silicon resin is preferable in consideration of electric characteristics.

  The content of the fine particles having a core-shell structure is preferably in the range of 3 to 30 parts by weight with respect to 100 parts by weight of the total of the epoxy resin and the curing agent. Thereby, the linear expansion coefficient in the surface direction and the thickness direction of the laminate can be further reduced. If it is less than 3 parts by weight, the effect of reducing the coefficient of linear expansion in the surface direction of the laminate may not be sufficient. When the amount is more than 30 parts by weight, the varnish prepared for impregnating the base material with the epoxy resin composition becomes remarkably thick, and it may be difficult to uniformly impregnate the base material.

  The size of the fine particles having a core-shell structure is preferably in the range of 0.1 to 10 μm. Accordingly, the flexible component is effectively dispersed in the epoxy resin composition, and the linear expansion coefficient in the plane direction and the thickness direction of the laminated board can be further reduced.

  Further, rubber fine particles having no core-shell structure can be used in combination as a flexible component of the present invention. By using the rubber fine particles in combination, the linear expansion coefficient in the surface direction of the laminate can be reduced. Examples of such rubber fine particles include acrylic rubber, silicon rubber, and nitrile butadiene rubber. The size of the rubber fine particles is preferably in the range of 0.1 to 10 μm, and the content is in the range of 3 to 30 parts by weight with respect to 100 parts by weight of the total of the epoxy resin and the curing agent. Is preferred. By setting it as such a particle size and content, it can disperse | distribute effectively in an epoxy resin composition.

  An inorganic filler can be mix | blended with the epoxy resin composition of this invention as needed. By blending the inorganic filler, the linear expansion coefficient in the thickness direction of the laminate obtained using the epoxy resin composition can be further reduced, and the laminate can be toughened. The inorganic filler is not particularly limited, but silica, aluminum hydroxide, magnesium hydroxide, E glass powder, alumina, magnesium oxide, titanium dioxide, calcium silicate, calcium carbonate, clay, talc, etc. These can be used, and these can be used alone or in combination. As content of a filler, it is preferable that it is the range of 10-100 weight part with respect to a total of 100 weight part of an epoxy resin and a hardening | curing agent. By setting it as such content, the above effect can be made still more effective.

  The epoxy resin composition of the present invention is blended with the above-described epoxy resin, curing agent, flexible component, and, in some cases, a curing accelerator and an inorganic filler, and these are uniformly mixed with a mixer, blender, or the like. Thus, an epoxy resin composition is prepared.

  The prepreg of the present invention can be produced by impregnating a base material with the epoxy resin composition prepared as described above, followed by drying by heating and semi-curing the epoxy resin composition in the base material. . In producing the prepreg, an epoxy resin composition may be dissolved in an organic solvent to prepare a resin varnish, and the substrate may be impregnated with the resin varnish. For example, after impregnating the base material in a resin varnish to impregnate the base material with the resin varnish, the epoxy resin composition in the base material is dried by heating at a temperature of about 120 to 180 ° C. It can be produced by removing the solvent and semi-curing to the B stage state. The amount of the prepreg thus produced impregnated with the epoxy resin composition is not particularly limited, but is preferably in the range of 30 to 70% by weight. As the organic solvent, for example, toluene, xylene, benzene, dimethylformamide, ketones, alcohols, cellosolves and the like can be used. Examples of the substrate include glass cloth, aramid cloth, polyester cloth, glass nonwoven fabric, and paper.

  The laminated plate of the present invention is obtained by laminating a predetermined number of the above prepregs and further laminating metal foils, for example, at a heating temperature of 150 to 300 ° C., a pressure of 0.98 to 6.0 MPa, and a time of 10 to 240 minutes. It can be manufactured by heating and pressurizing under conditions. The metal foil is laminated on one side or both sides of the prepreg. As the metal foil, copper foil, aluminum foil or the like is used. The thickness of the metal foil is generally 3 to 105 μm, and particularly preferably 12 to 35 μm.

  And a printed wiring board can be obtained by producing a conductor pattern by carrying out an etching process etc. on the surface of the metal foil of said laminated board, and forming a circuit.

  Hereinafter, examples will be shown and described in more detail. Of course, the present invention is not limited by the following examples.

<Examples 1-6>
Methyl ethyl ketone was added to the formulation under the conditions shown in Table 1 to prepare an epoxy resin varnish having a solid content of 65% by weight. This was impregnated into E glass cloth having a thickness of 0.1 mm and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 45% by weight. Eight prepregs manufactured were stacked, and a copper foil having a thickness of 18 μm was placed on both sides to form a pressure-receiving body, and the copper foil was bonded to both sides by heating and pressing for 100 minutes under conditions of a temperature of 190 ° C. and a pressure of 5 MPa. A copper clad laminate was obtained.

The surface expansion direction of the obtained copper-clad laminate (base material vertical direction and horizontal direction) and the linear expansion coefficient in the thickness direction were measured by the following methods, and the obtained results are shown in Table 1. Note that the linear expansion coefficient in the surface direction and the thickness direction can be evaluated as the thermal expansion coefficient in the surface direction and the thickness direction, respectively, and therefore, the linear expansion coefficient and the thermal expansion coefficient are synonymous here.
"Measurement method of thermal expansion coefficient"
Sample for measurement: Laminate measuring device from which copper foil was removed by etching: TMA device "TMA / SS6100" manufactured by Seiko Instruments Inc.
Measurement conditions: Temperature rising speed 10 ° C / min, Measurement temperature range 40-80 ° C
<Comparative Examples 1-2>
Methyl ethyl ketone was added to the formulation under the conditions shown in Table 1 to prepare an epoxy resin varnish having a solid content of 65% by weight. This was impregnated into E glass cloth having a thickness of 0.1 mm and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 45% by weight. Eight prepregs manufactured were stacked, and a copper foil having a thickness of 18 μm was placed on both sides to form a pressure-receiving body, and the copper foil was bonded to both sides by heating and pressing for 100 minutes under conditions of a temperature of 190 ° C. and a pressure of 5 MPa. A copper clad laminate was obtained.

The evaluation results are shown in Table 1.
<Comparative Example 3>
Dimethylformamide and methyl ethyl ketone were added to the formulation under the conditions shown in Table 1 to prepare an epoxy resin varnish having a solid content of 65% by weight. This was impregnated into E glass cloth having a thickness of 0.1 mm and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 45% by weight. Eight prepregs manufactured were stacked, and a copper foil having a thickness of 18 μm was placed on both sides to form a pressure-receiving body, and the copper foil was bonded to both sides by heating and pressing for 100 minutes under conditions of a temperature of 190 ° C. and a pressure of 5 MPa. A copper clad laminate was obtained.

  The evaluation results are shown in Table 1.

なお、表１において、＊１〜＊１１は次のものを表す。
＊１ ＹＤＢ４００（東都化成（株）製）
＊２ Ｎ７７５（大日本インキ（株）製）
＊３ Ｄ２０９０（大日本インキ（株）製）
＊４ スタフィロイドＡＣ−３８３２（ガンツ化成（株）製）
＊５ スタフィロイドＡＣ−４０３０（ガンツ化成（株）製）
＊６ ＳＬＭ４４５１４４（旭化成ワッカーシリコーン（株）製）
＊７ スタフィロイドＡＣ−３３５５（ガンツ化成（株）製）
＊８ トレフィルＥ−６００（東レ・ダウ・コーニング・シリコーン（株）製）
＊９ ＳＯ−Ｃ５（（株）アドマテックス製）
＊１０ ＳＮ−１９０（新日鐵化学（株）製）
表１より、硬化剤としてフェノール類ノボラック樹脂を使用し、コアシェル構造を有しシェル部分がエポキシ樹脂と反応する官能基を含む樹脂で構成されている微粒子を用いることで（実施例１〜６）、面方向および厚み方向の線膨張係数が小さい積層板が得られていることが確認された。シリコンゴムを併用した実施例４においては、さらに面方向の線膨張係数が小さい積層板が得られ、シリカを併用した実施例５においては、厚み方向の線膨張係数が小さい積層板が得られていることが確認された。

In Table 1, * 1 to * 11 represent the following.
* 1 YDB400 (manufactured by Toto Kasei Co., Ltd.)
* 2 N775 (Dainippon Ink Co., Ltd.)
* 3 D2090 (Dainippon Ink Co., Ltd.)
* 4 Staphyloid AC-3832 (manufactured by Ganz Kasei Co., Ltd.)
* 5 Staphyloid AC-4030 (manufactured by Ganz Kasei Co., Ltd.)
* 6 SLM445144 (Asahi Kasei Wacker Silicone Co., Ltd.)
* 7 Staphyloid AC-3355 (manufactured by Ganz Kasei Co., Ltd.)
* 8 Trefil E-600 (Toray Dow Corning Silicone Co., Ltd.)
* 9 SO-C5 (manufactured by Admatechs)
* 10 SN-190 (manufactured by Nippon Steel Chemical Co., Ltd.)
From Table 1, phenol novolak resin is used as a curing agent, and by using fine particles composed of a resin having a core-shell structure and a shell portion containing a functional group that reacts with an epoxy resin (Examples 1 to 6) It was confirmed that a laminated sheet having a small linear expansion coefficient in the plane direction and the thickness direction was obtained. In Example 4 in which silicon rubber is used in combination, a laminate having a smaller linear expansion coefficient in the surface direction is obtained, and in Example 5 in which silica is used in combination, a laminate having a small linear expansion coefficient in the thickness direction is obtained. It was confirmed that

On the other hand, in Comparative Example 1 in which fine particles composed of a resin containing a functional group that has a core-shell structure and the shell portion reacts with an epoxy resin are not blended, it is confirmed that the linear expansion coefficient in the surface direction and the thickness direction is large It was done. In Comparative Example 2 in which fine particles composed of a resin having a core-shell structure and containing no functional group that reacts with an epoxy resin is blended in the shell portion, the linear expansion coefficient in the plane direction is small, but the line in the thickness direction is small. It was confirmed that the expansion coefficient becomes large. In Comparative Example 3 in which dicyandiamide was used as the curing agent, it was confirmed that the effect of reducing the linear expansion coefficient in the plane direction and the thickness direction was small.

Claims (8)

A resin composition containing an epoxy resin, a curing agent, and a flexible component, wherein the curing agent is a phenol novolac resin, and the flexible component has a functional group that has a core-shell structure and the shell portion reacts with the epoxy resin. including contain fine particles that are made of resin, the functional group is a hydroxyl group, an epoxy resin composition comprising at least one functional group der Rukoto of carboxyl groups and epoxy groups. The core part of a core- shell structure is an acrylic resin, The epoxy resin composition of Claim 1 characterized by the above-mentioned. 2. The epoxy resin composition according to claim 1 , wherein the core portion of the core- shell structure is a silicon resin . The epoxy resin composition according to claim 1, characterized that you containing rubber particles as the elastic component 3. The epoxy resin composition according to claim 1, further comprising an inorganic filler . A prepreg characterized by impregnating a base material with the epoxy resin composition according to any one of claims 1 to 5, followed by drying by heating and semi-curing. A laminate obtained by laminating a predetermined number of the prepregs according to claim 6 and further laminating and arranging metal foils by heating and pressing. A printed wiring board comprising a conductor pattern formed on the surface of the metal foil according to claim 7.