JPH05318638A - Laminated sheet - Google Patents

Abstract

PURPOSE:To improve heat resistance by using a glass fiber base material as a surface layer, then a base material containing aramid fiber as a core layer, and improving workability with a drill with the minimization of a difference in shrinkage between the layers during heating. CONSTITUTION:A laminated sheet is composed of a glass fiber base material as a surface layer and a base material containing an aramid fiber as a core layer. The aramid fiber base material is of woven cloth or unwoven cloth (including paper). However, if the unwoven cloth is used, the woven cloth and the unwoven cloth are used in a combined form as the woven cloth is used on the other base material. If a large amount of SiO2 component is contained in the glass fiber, the base material becomes one having a lower thermal expansion. Thus it is possible to further lower the thermal expansion of the entire laminated sheet. The resin of the same quality is used as a resin for an organic layer used for the impregnation of the base material, in order to ensure that the layer is adhesive.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate for a surface mounting printed wiring board which has a small thermal expansion and is excellent in workability.

[0002]

2. Description of the Related Art As electronic parts have become smaller and highly integrated, the density of parts mounted on a printed wiring board has increased. Substrate materials are also strongly required to have characteristics such as low thermal expansion coefficient and dimensional stability. A laminated board using a cellulosic fiber such as paper or a glass fiber as a base material cannot meet this requirement because it has a large coefficient of thermal expansion and poor dimensional stability. Therefore, an aramid fiber base material having a small thermal expansion has been used.

[0003]

However, since the laminate using the aramid fiber as the base material has poor drill machinability, the inner wall of the through hole hole is not smooth and the through hole plating is not adhered. It had the drawback of not being good. The present invention aims to improve the drill machinability by utilizing the advantages of aramid fiber.

[0004]

The present invention is a laminated plate in which the surface layer is made of a glass fiber base material and the center layer is made of a base material containing aramid fibers.

The thickness of the aramid fiber base material is not particularly limited, but in order to satisfy the low thermal expansion and workability, it is 0.05 to
It is about 1.5 mm. Either woven cloth or non-woven cloth (including paper) may be used. When a non-woven fabric is used for the aramid fiber substrate, it is desirable to combine the woven fabric and the non-woven fabric such that a woven fabric is used for another substrate.

Further, the SiO ₂ component in the glass fiber is adjusted to 60
When it is at least%, the base material has a lower thermal expansion, and the thermal expansion coefficient of the entire laminated plate can be further lowered.

As the resin with which the base material is impregnated, there are phenol resin, epoxy resin, polyimide resin, melamine resin, unsaturated polyester resin, vinyl ester resin and the like. In order to secure the adhesiveness of the layers, it is desirable that the resin of the organic layer be the same resin for all layers.

[0008]

Since the layer containing the aramid fiber is reduced, the drill workability is improved as a whole. Since the layer of aramid fiber is at the center, the characteristics of aramid fiber are also utilized. Further, by interposing a glass base material on both sides of the aramid fiber base material, copper foil, glass, since the base materials are arranged in the order of the coefficient of thermal expansion of aramid, during heating,
The difference in expansion and contraction between the layers is reduced, and the heat resistance is improved.

[0009]

【Example】

Example 1 An aramid fiber non-woven fabric having a basis weight of 140 g / m ² was impregnated with an epoxy resin varnish for a laminate, and the resin was B-staged to produce an aramid fiber base material prepreg having a resin content of 50%.
Glass cloth for electrical insulation board (SiO ₂ components 52-56
%) Was impregnated with the same epoxy resin varnish and the resin was B-staged to produce a glass fiber base material prepreg having a resin content of 45%. Two copper foils with a thickness of 35 μm, one glass fiber base material prepreg for each inside, and one aramid fiber base material prepreg for the center layer were placed at 175 ° C. for 60 minutes, 3 minutes.
A double-sided copper clad laminate having a thickness of 0.6 mm was manufactured by heating and pressurizing with a vacuum press (1333 to 8000 Pa) at MPa.

Example 2 A glass cloth (SiO ₂ component 60%) for an electric insulating plate was prepared.
The same epoxy resin varnish as used in Example 1 was impregnated and the resin was B-staged to produce a glass fiber base material prepreg having a resin content of 45%. 2 copper foils with a thickness of 35 μm
A double-sided copper-clad laminate was manufactured in the same manner as in Example 1 below by arranging one prepreg each on the inside and one aramid fiber base prepreg manufactured in Example 1 on the center layer.

Comparative Example 1 Two 35 .mu.m thick copper foils, one inside each of which was the aramid fiber base material prepreg obtained in Example 1, and a glass fiber base material prepreg manufactured in the same manner as in Example 1 Was placed in the center, and a double-sided copper-clad laminate was manufactured in the same manner as in Example 1.

Comparative Example 2 Two double-sided copper foils having a thickness of 35 μm and three aramid fiber base material prepregs obtained in Example 1 were placed inside the copper foil, and double-sided copper clad laminate was prepared in the same manner as in Example 1. Was manufactured.

Comparative Example 3 Two copper foils each having a thickness of 35 μm and three glass fiber base prepregs produced in the same manner as in Example 1 were arranged inside the copper foil, and double-sided copper-clad in the same manner as in Example 1. Laminates were manufactured.

The characteristics of these double-sided copper-clad laminates are shown in Table 1.

[0015]

[Table 1]

Drilling conditions Rotation speed: 60,000 r / min, Drill: Diameter 0.5
mm Spade type Feed rate: 30 μm / r / min 3 sheets stacked, 4000
Hit Hole Wall Roughness: Maximum hole wall roughness of the third 3,900 to 4,000 holes Climbing hole: Maximum hole climbing of the third 3,900 to 4,000 holes

[0017]

According to the present invention, since the glass fiber base material is used for the surface layer and the aramid fiber base material is used for the central layer, the aramid fiber has poor drilling workability due to the characteristics of the aramid fiber base material. Can be reduced.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Naruzawa 1500 Ogawa, Shimodate-shi, Ibaraki Hitachi Chemical Co., Ltd. Shimodate factory

Claims (1)

[Claims] 1. A laminate comprising a surface layer made of a glass fiber base material and a central layer made of a base material containing aramid fibers.