JPH0992945A - Printed board and prepreg which have low permittivity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable manufacturing by an ordinary manufacturing process, and reduce glass ratio and permittlvity without deteriorating usual characteristics and workability, by using compound cloth of glass-low permittivity insulating resin wherein filament of low permittivlty insulating resin is woven and mixed in glass filament. SOLUTION: Compound cloth of glass-low permettivity insulating resin is cloth formed by mixedly weaving glass filament and low permettivity insulating resin filament. The cloth is applied and impregnated with FR-4 resin, and prepreg is obtained by drying. The resin content of the prepreg is 50wt.%. Eight sheets of the prepreg are stacked, and both sides are sandwiched by conductive foils as conducting layers. A specific number of the sheets are loaded between heat plates via stainless plates. Under the conditions 25kgf/cm<2> and 190 deg.C, heating and pressing are performed for 90 minutes, thereby manufacturing a printed board. Dielectric characteristics, workability and cost are tested about the printed board. The result is that dielectric characteristics are excellent in spite of low glass ratio.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board and a prepreg which have excellent dielectric properties and can be manufactured at low cost by a usual process.

[0002]

2. Description of the Related Art As electronic devices have higher densities and higher signal speeds, substrates having a low dielectric constant have been required. However, it is known that a material having such characteristics is expensive and difficult to manufacture like a Teflon substrate, and that the workability of the substrate is significantly poor. Also, when manufacturing this substrate in the process of ordinary glass epoxy substrate,
It is common to use aramid fibers, glass having a high SiO ratio as a base material, or to significantly increase the resin ratio.

[0003]

However, the method of using the aramid fiber is poor in processability, has a drawback of easily absorbing moisture, and is expensive. The method of using a glass having a high SiO ratio as a base material is poor in workability and expensive as in the case of. The method of increasing the resin ratio of (1) had the drawback of poor moldability and poor stability of production.

The present invention has been made in order to solve the above-mentioned drawbacks, and an object of the present invention is to provide a printed circuit board and a prepreg which can be manufactured at low cost by a normal manufacturing process and which are excellent in dielectric characteristics and workability. .

[0005]

DISCLOSURE OF THE INVENTION As a result of intensive research aimed at achieving the above object, the present inventor has found that a glass-low dielectric insulating property obtained by weaving a filament of a low dielectric insulating resin into a glass filament is interwoven. By using a resin composite cloth, it has been found that the above object is achieved,
The present invention has been completed.

That is, the present invention provides a printed circuit board in which a prepreg obtained by coating and impregnating a base cloth with an insulating resin, drying and semi-curing, and a copper foil are superposed and integrally molded by heating and pressing, Using a prepreg obtained by coating and impregnating an insulating resin with a glass-low dielectric insulating resin composite cloth made of a glass filament and a low-dielectric insulating resin filament as a base material, drying and semi-curing It is a printed circuit board with a low dielectric constant. Further, it is a prepreg using a glass-low dielectric insulating resin composite cloth composed of a glass filament and a low dielectric insulating resin filament used therein.

The present invention will be described in detail below.

The glass-low dielectric insulating resin composite cloth used in the present invention is a cloth in which glass filaments and low dielectric insulating resin filaments are woven together. The glass filament used here is usually used for a laminated plate and is not particularly limited and can be widely used.

The low dielectric insulating resin filament is usually used for a laminated board and has a dielectric constant of 1
The MHz is preferably 4.0 or less, and specific resins include, for example, polyphenylene ether and polyphenylene oxide, but are not particularly limited. Moreover, you may add and mix a filler and rubber as needed. The shape of the filament is not particularly limited, but it is desirable that the cross section be close to a glass filament shape such as a circular shape so as not to impair the manufacturing stability as a cloth when the filament is bundled and woven. Although the diameter is not particularly limited, considering cost and productivity,
10 to 90 μm is preferable. As the bundle of filaments used for the glass-low dielectric insulating resin composite cloth, a mixture of glass filaments and low dielectric insulating resin filaments at a fixed ratio is used. The ratio is not particularly limited,
The volume ratio of glass is 5 to 95%, preferably 20 to 30%. If the ratio is less than 5%, the strength is insufficient, which is not preferable. Further, if it exceeds 95%, the dielectric constant is high, which is not preferable.
The weaving method of the glass-low dielectric insulating resin composite cloth is not particularly limited, and general flat folding, satin weaving and the like are used.

The composite cloth is coated and impregnated with an insulating resin, but the resin is not particularly limited, and an epoxy resin, a polyimide resin or the like which is usually used for a laminated board is used. The method of applying and impregnating the prepreg is not particularly limited as long as it can be applied and impregnated, dried and semi-cured to form B-stage.

FIG. 1 is a sectional view of a prepreg which schematically shows the state of a glass filament and a low dielectric insulating resin filament. A low-dielectric insulating resin filament 1 having a large diameter is combined with a glass filament 2 having a small diameter to be woven as a glass-low dielectric insulating resin composite cloth 4. The glass-low dielectric insulating resin composite cloth 4 is impregnated with the insulating resin 3, coated, dried and semi-cured. In the case where the insulating resin 3 and the low dielectric insulating resin filament 1 are not welded to each other, as shown in FIG. 1, the insulating resin 3 and the low dielectric insulating resin filament 1 are
Can be distinguished relatively well. In the case of a resin in which the insulating resin 3 and the low dielectric insulating resin filament 1 are welded together, the insulating resin 3 and the low dielectric insulating resin filament 1 are fused and integrated with each other to be in a well-impregnated state. Therefore, as shown by the chain line in FIG. 2, the insulating resin 3 and the low dielectric insulating resin filament 1 are fused and integrated so that they cannot be distinguished from each other, and the resin matrix state is also stable.

[0012]

The substrate cloth in the printed circuit board and prepreg of the present invention comprises a glass filament and a cured or semi-cured low dielectric insulating resin filament.
By using the glass-low dielectric insulating resin composite cloth, it was possible to manufacture by a normal manufacturing process, and it was possible to lower the glass ratio and lower the dielectric constant without impairing the conventional characteristics and workability. .

[0013]

Next, the present invention will be described by way of examples. The invention is not limited by these examples.

Examples 1 to 3 Using the cloths shown in Table 1, a resin of FR-4 was applied and impregnated and dried to obtain a prepreg. The resin content of this prepreg was 50% by weight. Eight prepregs are stacked, sandwiched on both sides with copper foil, which is a conductive layer, and a prescribed number of sheets are placed between hot plates via a stainless steel plate, 25 kgf / cm ² ,
A printed board was manufactured by heating and pressing for 90 minutes at 190 ° C.

Comparative Example 1 Using the cloth shown in Table 1, a resin of FR-4 was applied and impregnated and dried to obtain a prepreg. The resin content of this prepreg was 50% by weight. Eight prepregs are stacked, sandwiched on both sides with copper foil, which is a conductive layer, and a prescribed number of sheets are placed between hot plates via a stainless steel plate, 25 kgf / cm ² ,
A printed board was manufactured by heating and pressing for 90 minutes at 190 ° C.

Comparative Example 2 In Comparative Example 1, the resin content of the prepreg was 50% by weight.
A printed circuit board was manufactured in the same manner as in Comparative Example 1 except that the resin content was 70% by weight instead of.

Comparative Example 3 In Comparative Example 1, instead of the cloth shown in Table 1,
A printed circuit board was manufactured in the same manner as in Comparative Example 1 except that the S-glass material was used.

The printed boards obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were tested for dielectric properties, workability and cost. The results are shown in Table 1. In all cases, the characteristics of the present invention were excellent, and the effects of the present invention could be confirmed.

[0019]

[Table 1] * 1: Insulating resin is PPE SC-2100 (made by Asahi Kasei Co., Ltd.) * 2: ○: small amount of drill wear, ×: large amount of drill wear. * 3: The product cannot be obtained due to slippage during molding.

[0020]

As is clear from the above description and Table 1, the printed circuit board and prepreg of the present invention have excellent dielectric properties and workability, even though they have a low glass ratio, and contribute to cost reduction. .

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing an embodiment of a prepreg of the present invention.

FIG. 2 is a sectional view schematically showing another embodiment of the prepreg of the present invention.

[Explanation of symbols]

 1 Low Dielectric Insulating Resin Filament 2 Glass Filament 3 Insulating Resin 4 Glass-Low Dielectric Insulating Resin Composite Cloth

Claims (2)

[Claims] 1. A base cloth is coated and impregnated with an insulating resin,
In a printed circuit board in which a prepreg obtained by drying and semi-curing and a copper foil are overlaid and integrally molded under heating and pressure, a glass-low dielectric insulating property composed of a glass filament and a low dielectric insulating resin filament is used. A printed board having a low dielectric constant, which comprises a prepreg obtained by coating and impregnating an insulating resin on a resin composite cloth as a base material, drying and semi-curing the resin. 2. A glass-low dielectric insulating resin composite cloth comprising a glass filament and a low dielectric insulating resin filament as a base cloth, and a glass-low dielectric insulating resin composite cloth base. A prepreg for a printed circuit board having a low dielectric constant, which is obtained by coating and impregnating a material cloth with an insulating resin, drying and semi-curing the material.