JP2659490B2 - Printed circuit laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated board for a printed circuit used in electric equipment, electronic equipment, communication equipment and the like.

[0002]

2. Description of the Related Art Consumer electronic devices have become smaller and more sophisticated, and a printed wiring board used for the same has a structure in which a glass nonwoven fabric is used as an intermediate layer base material and a glass woven fabric is used as a surface layer substrate. (Hereinafter referred to as a composite laminate) has been used. Accordingly, tracking resistance has been required for televisions and air conditioners to which a high voltage is applied from the standpoint of ensuring safety.

[0003] Also, in industrial electronic equipment, tracking resistance has been required from the standpoint of ensuring safety. Conventionally, in phenolic resin laminates used in consumer equipment, melamine resin, alicyclic epoxy or polyester resin, which hardly carbonizes, is used as the adhesive used to adhere the metal foil to the laminate, due to this tracking resistance. Has been used. However, epoxy laminates such as composite laminates tend to be thinner as the size and density increase, so it is difficult to apply an adhesive to the metal foil, or it may curl after coating. This makes it impossible to use the metal foil with adhesive. On the other hand, in industrial equipment, an alicyclic epoxy resin or a type of resin having a small number of aromatic rings such as an unsaturated polyester resin has been used for improving tracking resistance, but the cost is high, heat resistance,
There were problems such as weak peel strength with metal foil.

[0004]

SUMMARY OF THE INVENTION The present invention has been made as a result of various studies to solve the above problems.
An object of the present invention is to provide a printed circuit board having tracking resistance without deteriorating electrical characteristics and other various characteristics.

[0005]

According to the present invention, the surface layer is made of a thermosetting resin glass woven fabric containing an inorganic filler in an amount of 10 to 200% by weight based on the resin of the surface layer, and the intermediate layer is made of an inorganic material. Filler is 10 to 200% by weight based on the resin of the intermediate layer
A laminate for a printed circuit, comprising a thermosetting resin nonwoven fabric contained therein.

The inorganic filler used in the present invention accounts for 10 to 200%, preferably 20 to 150%, of the resin of the surface layer.
%included. If it is less than 10%, the effect of tracking resistance is small, and if it is more than 200%, the resin viscosity at the time of mixing the inorganic filler becomes too high, and it becomes difficult to impregnate the glass woven fabric substrate. In the intermediate layer, the content of the inorganic filler is preferably from 10 to 200%, more preferably from 60% to 200%, based on the resin of the intermediate layer. If it is less than 10%, dimensional stability and through-hole plating reliability are undesirably reduced. If it is more than 200%, the viscosity becomes too high when the inorganic filler is mixed with the resin, and it becomes difficult to impregnate the glass nonwoven fabric. Examples of the inorganic filler include aluminum hydroxide, silica, talc, wollastonite, magnesium hydroxide, and clay. Of these, aluminum hydroxide is preferred from the viewpoints of flame retardancy, workability, and heat resistance. When aluminum hydroxide is used for the surface layer, the effect of improving tracking resistance is large.

The thermosetting resin used in the present invention is preferably an epoxy resin. In addition, a polyimide resin, a polyester resin, a phenol resin and the like can be used. ADVANTAGE OF THE INVENTION According to this invention, while maintaining tracking resistance and maintaining solder heat resistance and copper foil peeling strength, surface roughness can be improved by inserting an inorganic filler between filaments of a glass woven fabric. .

[0008]

[Function] The reason why the inorganic filler compounded in the thermosetting resin of the surface layer improves the tracking resistance is that the inorganic filler is present on the surface of the formed laminated board, thereby reducing the proportion of the resin on the surface. It is thought to decrease. Aluminum hydroxide (alumina hydrate) is preferred as the inorganic filler because aluminum hydroxide is decomposed by the heat of discharge to generate water, and water reacts with the organic matter decomposed by the discharge to become volatile. It is considered that the formation of the material prevents formation of tracks.

[0009]

Examples of the present invention and comparative examples (conventional examples) are described below.
Is shown. Example 1 The composition of a varnish containing an epoxy resin is as follows. (1) 100 parts of brominated epoxy resin (Ep-1046 manufactured by Yuka Shell) (2) Dicyandiamide 4 (3) 2-ethyl 4-methylimidazole 0.15 (4) Methyl cellosolve 36 (5) Acetone 60 To produce a uniform varnish. Subsequently, an inorganic filler having the following composition was added to the epoxy resin-containing varnish with respect to 100 parts of the resin component, followed by stirring and mixing to prepare an inorganic filler-containing varnish. (1) Gibbsite type aluminum hydroxide 50 parts (Heidilite H-42 manufactured by Showa Denko) (2) Ultra fine powdered silica (Carplex manufactured by Shionogi Pharmaceutical Co., Ltd.) 2 parts WE-
18KRB-84) to obtain a glass woven fabric prepreg by impregnating and drying so that the resin content becomes 30 to 40%. Subsequently, an inorganic filler having the following composition was added to the epoxy resin-containing varnish with respect to 100 parts of the resin component, followed by stirring and mixing to prepare an inorganic filler-containing varnish (2). (1) 25 parts of silica (Crystalite VX-3 manufactured by Tatsumori) (2) 70 parts of gibbsite type aluminum hydroxide (Heidilite H-42 manufactured by Showa Denko) (3) Ultrafine powdered silica (Carplex manufactured by Shionogi Pharmaceutical) 5 parts The inorganic filler-containing varnish (2) was impregnated and dried in a glass nonwoven fabric (Nippon Vilene Ep-4075) so that the content of the resin and the inorganic filler became 90%, to obtain a glass nonwoven prepreg. Next, the glass woven prepreg was used as an intermediate layer, the glass woven prepreg was placed on the upper and lower surface layers, and a copper foil having a thickness of 18 μm was further laminated thereon. The molding temperature was 165 ° C. and the pressure was 60 kg / cm ² for 90 minutes. Lamination molding was performed to obtain a copper-clad laminate having a thickness of 1.6 mm. Example 2 In the glass woven prepreg of Example 1, a gibbsite type aluminum hydroxide (Heidilite H- manufactured by Showa Denko KK)
A copper-clad laminate was obtained in the same manner as in Example 1, except that 42) was changed from 50 parts to 100 parts. Comparative Example In the glass woven prepreg of Example 1, a glass woven prepreg was prepared by impregnating and drying only the epoxy resin so that the resin content became 35 to 45% in the glass woven fabric without adding an inorganic filler. Except for the above, a copper clad laminate was obtained in the same manner as in Example 1. In the above Examples and Comparative Examples, the tracking resistance, solder heat resistance, and copper foil peeling strength are shown in Table 1.
Shown in

[0010]

[Table 1]

The dimensional stability, through-hole plating reliability, electrical insulation characteristics, etc. were also measured, but no difference was observed between the examples and the comparative examples.

[0012]

The printed circuit laminate of the present invention is excellent in tracking resistance, heat resistance, copper foil peeling strength and surface smoothness, and is therefore extremely suitable for industrial use.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H05K 1/03 630 H05K 1/03 630F

Claims (1)

(57) [Claims] The surface layer is made of a thermosetting resin glass woven fabric containing an inorganic filler in an amount of 10 to 200% by weight with respect to the resin of the surface layer. A laminate for a printed circuit, comprising a thermosetting resin nonwoven fabric containing 10 to 200% by weight of the laminate.