JPH05251836A - Prepreg and substrate for metal core printed-wiring board - Google Patents

Abstract

PURPOSE:To form a resin, which is filled in a through hole in a metal core, into a resin, in which a crack is not caused, by a work subsequent to the filling of the resin. CONSTITUTION:A filler, which consists of particles, 5.0 or below in length/ breadth ratio and is subjected to coupling treatment, is blended in a resin and the blend is impregnated in a fiber base material in such a way that its coating amount to the base material becomes 50 to 85wt.% to be formed into prepregs 2. These prepregs 2 are superposed on metal plates 1, are heated and pressed to form into a substrate for metal core printed-wiring board use.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prepreg suitable for forming an insulating layer of a metal core printed wiring board and a metal core printed wiring board.

[0002]

2. Description of the Related Art A substrate for a metal core printed wiring board has an iron or aluminum metal plate as a core or a base, and a conductor layer provided on the metal plate via an insulating layer mainly composed of a resin. A prepreg is usually used to form the insulating layer. In a metal plate provided with through holes for through holes or blind holes, the through holes are filled with resin in order to insulate the conductor layer and the metal plate. This hole filling is generally performed by pouring the resin of the prepreg when the metal plate and the prepreg are superposed and heated and pressed to be integrated (see Japanese Patent Publication No. 51-37301). A method is also known in which the through holes are pre-filled with a resin to improve the filling property.

[0003]

After filling the hole, a hole having a diameter smaller than the diameter of the hole of the metal plate which has been previously drilled is opened in this resin portion, and this hole is plated. However, cracks may occur in the resin filling the holes during this hole forming step and subsequent soldering. Recently, the temperature of soldering process has risen and it has been exposed for a long time.
The tendency is getting bigger and bigger.

An object of the present invention is to prevent the resin filling the holes from being cracked by the subsequent processing.

[0005]

According to the present invention, cracks generated in a resin filling holes have a major axis / minor axis ratio of 5.0.
Adhesion amount of resin component containing the following filler is 50-85
The problem was solved by using a prepreg impregnated in a fiber base material so that the weight percentage became, and filling the holes provided in the metal plate with the resin contained in the prepreg.

The filler to be mixed with the resin is preferably an inorganic oxide such as silica, alumina or magnesia, or a powder such as glass. Further, organic fillers such as fluorine resin and silicone resin can also be used. The ratio of the major axis to the minor axis of the filler is related to the fluidity of the resin, and if it is out of this condition, the filling property of the resin into the holes provided in the metal plate is deteriorated. The blending amount of the filler is 5 to 50% by weight. If it is less than 5% by weight, there is no effect, and if it exceeds 50% by weight (filler / resin = 1/1), it cannot be uniformly dispersed in the resin, and the fluidity of the resin component deteriorates, and the holes formed in the metal plate The filling property into the inside becomes poor.

Further, it is more effective to use those having an average particle diameter of 10 μm or less and treat with a coupling agent.
As the coupling agent, vinyltrichlorosilane, vinyltris (βmethoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4
Epoxycyclohexyl) ethyltrimethoxysilane,
γ-glycidoxypropyltrimethoxysilane, N-β
(Aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, γmercaptopropyltrimethoxysilane, γ-
In addition to chloropropyltrimethoxysilane, etc., isopropyltriisostearoyl titanate, isopropyltridodecylbenzenesulfonyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetraoctyl bis (ditridecyl phosphite) titanate , Tetra (2,2-diallyloxymethyl-1-butyl) bis (di-tridecyl) phosphite titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, and the like. Used alone or in combination.

As the resin with which the fiber base material is impregnated, thermoplastic resins such as vinyl chloride resin, methacrylic resin, polyamide resin, polyethylene resin, fluorine resin and polycarbonate resin, phenol resin, urea resin, melamine resin, polyurethane resin Thermosetting resins such as unsaturated polyester resins, silicone resins, epoxy resins and polyimide resins may be used, and thermoplastic resins and thermosetting resins may be used in combination. The filler is treated with a coupling agent, dispersed in these resins, and impregnated into the fiber base material to obtain a prepreg.

Then, as shown in FIG. 1, the prepreg 2 is superposed on a metal plate 1 having a through hole at a predetermined position, and a metal foil 3 is superposed on the outer side thereof, and heated and pressed to prepreg the through hole. A metal core printed wiring board substrate is obtained by burying the resin inside.

FIG. 2 shows an example of a metal core multilayer printed wiring board substrate manufactured using the prepreg according to the present invention. The prepregs 2 are arranged on both sides of the metal plate 1 having through holes at predetermined positions, the thick copper foil-clad laminate 4 and the copper-clad laminate 5 are laminated on the outer side thereof, and the copper foil is laminated on the outer side thereof and heated. The pressure is applied to fill the through holes with the resin of the prepreg. You can also use two or more metal plates.

[0011]

[Function] It is considered that the filler reinforces the resin and makes cracks less likely to occur. Furthermore, the resin content of the prepreg is 50 to 85% by weight, and the major axis / minor axis ratio of the filler is 5.0 or less, so that the fluidity of the resin is good and the filling property into the holes provided in the metal plate is also good. Is.

[0012]

Example 1 30 parts of a glass powder having an average particle size of 3 μm and a maximum particle size of 10 μm or less was mixed and kneaded with 100 parts (parts by weight, the same applies hereinafter) of a solid content of brominated epoxy resin. A glass fiber cloth was impregnated with this kneading varnish so that the resin content in the prepreg was 70% by weight to obtain a prepreg. Thickness 1.
A required number of holes with a diameter of 2 mm are drilled in a 0 mm aluminum plate, three prepregs are stacked on each side of the aluminum plate, and copper foil having a thickness of 35 μm is stacked on both outer sides of the aluminum plate and heated at 170 ° C. and 4 MPa for 90 minutes. Pressurized to obtain an aluminum core double-sided copper clad substrate.

Example 2 The resin was replaced with an epoxy-modified polyimide resin, and an aluminum core double-sided copper clad substrate was obtained in the same manner as in Example 1 below.

Comparative Example 1 An aluminum core double-sided copper clad substrate was obtained in the same manner as in Example 1 except that the glass powder was not mixed with the resin varnish.

Comparative Example 2 An aluminum core double-sided copper clad substrate was obtained in the same manner as in Example 2 except that glass powder was not added.

For each of the aluminum-core double-sided copper-clad substrates obtained in Examples 1 and 2 and Comparative Examples 1 and 2, the diameter was 1. mm through holes were formed, the inner wall was plated, and the solder was floated at 288 ° C. Table 1 shows the state of crack generation during through-hole processing and solder float.

[0017]

[Table 1]

Example 3 A 0.5% by weight aqueous solution of γ-aminopropyltriethoxysilane was atomized at a rate of 100 g per 1 kg of glass powder having an average particle size of 3 μm and a maximum particle size of 10 μm or less, and stirred to uniformly disperse. And dried at 130 ° C. for 15 minutes. 30 parts of this glass powder was mixed and kneaded with 100 parts of the solid content of the brominated epoxy resin. A glass fiber cloth was impregnated with this kneading varnish so that the resin content in the prepreg was 70% by weight to obtain a prepreg. Thereafter, an aluminum core double-sided copper clad substrate was obtained in the same manner as in Example 1.

Example 4 The resin was replaced with an epoxy-modified polyimide resin, and an aluminum core double-sided copper clad substrate was obtained in the same manner as in Example 3 below.

For each of the aluminum core double-sided copper clad substrates obtained in Examples 3 and 4, the diameter was 1. mm through holes were formed, the inner walls were plated, and the solder was floated at 288 ° C. and 300 ° C. Table 2 shows the crack generation status.

[0021]

[Table 2]

[0022]

According to the present invention, the resin content of the prepreg is 50 to 85% by weight, and the resin is mixed with the filler having the ratio of major axis / minor axis of 5.0 or less. At the time of manufacturing the substrate for use, the resin can be easily filled into the holes provided in the metal plate serving as the core, and cracks do not occur during the subsequent processing. Further, the filler subjected to the coupling treatment does not generate cracks even during the high temperature solder treatment.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a metal core printed wiring board substrate.

FIG. 2 is a cross-sectional view of a metal core multilayer printed wiring board substrate.

[Explanation of symbols]

 1 Metal Plate 2 Prepreg 3 Metal Foil 4 Thick Copper Clad Laminate 5 Copper Clad Laminate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hatsue Saito 1500 Ogawa, Shimodate, Ibaraki Shimodate, Hitachi Chemical Co., Ltd. (72) Inventor Mitsuo Yokota 1500 Ogawa, Shimodate, Ibaraki Hitachi Chemical Co., Ltd. Inside the Shimodate Factory (72) Inventor Tatsuya Oda 1500 Ogawa, Shimodate City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Shimodate Factory (72) Inventor Naoki Teramoto 1500 Ogawa, Shimodate City, Ibaraki Hitachi Chemical Co., Ltd.Shimodate Factory

Claims (3)

[Claims] 1. A prepreg obtained by impregnating a fiber base material with a resin component mixed with a filler having a ratio of major axis / minor axis of 5.0 or less so that the adhered amount is 50 to 85% by weight. 2. The prepreg according to claim 1, wherein the filler is a filler subjected to a coupling treatment. 3. A substrate for a metal core printed wiring board in which the prepreg according to claim 1 is placed on a metal plate having a through hole at a predetermined position, heated and pressed to fill the through hole with a resin in the prepreg.