JP2523649B2 - Glass fiber woven reinforced printed wiring board - Google Patents

Description

The present invention relates to an electrical insulating plate or a printed wiring board used in industrial equipment, electronic equipment, telecommunications equipment and the like.

[Conventional technology]

The most required properties of printed wiring boards in the above fields are dimensional stability, mechanical strength, electrical properties, heat resistance, chemical resistance, etc., but a substrate for printed wiring boards that also has these properties. Conventionally, a glass fiber woven fabric is generally used.

The material for the printed wiring board is obtained by laminating and molding a plurality of fabrics using a thermosetting resin as a binder. The material for the printed wiring board is cured and shrunk by heat and pressure in the laminating process. Due to the stress caused by the stress, a dimensional change occurs, and a fatal defect such as warp twist of the laminated plate or cutting of through-hole plating occurs. Heretofore, attempts have been made to improve the dimensional stability by using a glass fiber woven fabric as a substrate for a printed wiring board, effectively changing warp and weft of the glass fiber woven fabric. That is, the relationship between the glass fiber woven fabric used as the substrate and the dimensional stability of the printed wiring board can be improved by making the number of warp threads and the number of weft threads as equal as possible. Kaisho 54-10
As disclosed in Japanese Unexamined Patent Publication No. 8270, there is a way of thinking that the number of warp threads and the number of weft threads can be changed, or that a single thread can be used for improvement.

[Problems to be solved by the invention]

However, in recent years, there has been a strong demand for higher density of printed wiring boards, especially multilayer printed wiring boards, so that the dimensional stability of materials for printed wiring boards is not satisfactory at the current level, and printing with higher dimensional stability is achieved. Wiring board materials have become necessary.

An object of the present invention is to provide a printed wiring board that is particularly excellent in dimensional stability among the characteristics required for printed wiring boards in this field.

[Means for solving problems]

The present invention possesses characteristics such as mechanical strength, electrical characteristics, heat resistance, and chemical resistance that are almost comparable to those of conventional laminated sheets using only glass fiber fabric as a base material.
And as a result of intensive research to develop a glass fiber woven fabric reinforced laminate having very excellent dimensional stability, by improving the woven structure of the glass fiber woven fabric of the base material, it was found that the above objects can be achieved, The present invention has been completed.
That is, the glass fiber woven fabric reinforced printed wiring board according to the present invention comprises a laminated plate obtained by laminating and molding a plurality of glass fiber woven fabrics using a thermosetting resin as a binder, and the glass fiber woven fabric includes two warp yarns and two weft yarns. As described above, the glass fiber woven fabric-reinforced printed wiring board is characterized in that it is made of a normal satin weave that simultaneously floats up and down five or less.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings showing an example of a glass fiber woven fabric used as a base material of a glass fiber woven fabric reinforced printed wiring board according to the present invention.

FIG. 1 shows a structural diagram of the glass fiber woven fabric. FIG. 1A shows a 2/2 Nanako weave, and FIG. 1B shows a 3/3 Nanako weave.

The glass fiber woven fabric used in the present invention is of a type that has never been used as a glass woven fabric for printed wiring boards, and its characteristic is that, as shown in FIG. 1, two or more warp and weft yarns are used at the same time. It is to set it up and down, and to make the plain weave expand. Further, both the warp and the weft are floated and set at least 2 and 5 or less at the same time. When the number is 6 or more, it becomes extremely difficult to maintain the woven structure.

It is surprising that the dimensional stability of the printed wiring board is remarkably improved by using the glass fiber woven fabric having the same number of warp yarns and weft yarns and having a structure in which a plurality of warp yarns and weft yarns are simultaneously floated and sunk.

The glass fiber woven fabric used in the present invention functions particularly effectively for a multilayer printed wiring board which requires extremely high dimensional stability. Of the multilayer printed wiring boards,
Of course, the effect will be exhibited whether it is used for both the copper clad laminate as the inner layer and the prepreg, or for either one, and it is suitable for the prepreg.

The yarn used in the glass fiber woven fabric used in the present invention is not limited in the single yarn diameter, the number of bundles, and the like as long as it is a glass long fiber. Further, the composition of glass is not particularly limited.

The thermosetting resin used as the binder in the present invention refers to a resin that can be cured by heat, and for example, an epoxy resin, a polyimide resin, a phenol resin, which has been conventionally used in the production of a laminate having a glass fiber fabric as a base material, Polyester resins, silicone resins, polyurethane resins, polyvinyl butyral resins and mixtures thereof can be used, but are not limited to these.

The absolute value of the dimensional stability of the printed circuit board material of the present invention varies depending on the type of thermosetting resin used, of course, but the degree of the deviation is relatively the same as when using a conventional glass fiber woven fabric. The type of resin used does not impair the characteristics achieved by the present invention.

The glass fiber woven fabric used in the present invention is subjected to high-temperature desizing treatment, and then impregnated with the resin, a surface treatment agent, for example, a treatment with a silane coupling agent is performed as usual. It is not limited.

Manufacture of the material for printed circuit boards can be performed according to a conventional method. That is, generally, a glass fiber woven fabric is impregnated with a resin, semi-cured prepregs are stacked, and compression heat molding is performed. At that time, it is preferable that the prepreg is sufficiently impregnated and contains no bubbles, and it is preferable that the glass fiber woven fabric as the base material is entirely covered. Further, a method of casting or a method of low-pressure heating is also possible. Further, usually, a metal film such as a copper foil is pasted and formed on one surface or both surfaces of the laminated plate, but a method of adhering the circuit-forming material after the forming is also possible like an additive method.

〔Example〕

Hereinafter, examples of the glass fiber woven fabric reinforced printed wiring board according to the present invention and a glass fiber woven fabric used as a substrate thereof will be shown, together with a performance comparison with comparative examples.

The dimensional stability of a printed circuit board used as a performance comparison was measured by the following method.

In order to measure the dimensional stability, 8 pieces of semi-cured prepreg impregnated with resin in a predetermined glass fiber woven fabric are overlapped, 35 μm thick copper foil is pasted on both sides, compression heat molding is performed, and A printed circuit board having dimensions as shown in FIG. 2 was prepared. In this measurement method, instead of forming a circuit, the marking points 2 are partially attached to 9 points on the copper foil on the surface of the copper clad laminate, and the distance between the marking points 2 is measured at 6 points in the longitudinal direction and the weft direction (measurement After the value a), the copper foil was removed by etching except for the mark points. Then, after heat treatment at 170 ℃, 30 minutes,
Again, the gauge length was measured (measured value b), and the dimensional stability was evaluated using the ratio of the difference between the measured value a and the measured value b to the measured value a as the dimensional change amount.

Example 1 The warp and weft are composed of ECG75 1/0 and have a density of warp.
A glass fiber woven fabric consisting of 44 threads / 25 mm and 32 wefts / 25 mm was used, and the weaving structure was a normal satin weave (see FIG. 1A) in which two warps and two wefts simultaneously rise and fall.

Example 2 The warp and weft are composed of ECG75 1/0 and have a density of warp
A glass fiber woven fabric composed of 44 yarns / 25 mm and wefts 32 yarns / 25 mm was used, and the weave design was a normal satin weave (see FIG. 1B) in which two warps and two wefts were simultaneously floated and sunk.

Comparative Example 1 The warp and weft are composed of ECG75 1/0 and have a density of 44
A glass fiber woven fabric having a woven structure of 25/25 mm and 32 wefts / 25 mm and having a plain weave was woven.

Example 3 The glass fiber woven fabric woven in Example 1 was impregnated with the epoxy resin varnish of the following formulation example, and dried by heating at 125 ° C. to prepare a prepreg. Eight of these prepregs and on the surface
35μ copper foil is layered and compression molded at 175 ℃, 30kg / cm ² ,
A 1.6 mm thick copper clad laminate was obtained.

Resin varnish formulation AER-711 (Epoxy resin manufactured by Asahi Kasei) 100 parts Dicyandiamide 2.5 parts Benzyldimethylamine 0.2 parts Dimethylformamide 12 parts Methylcellosolve 12 parts Methylethylketone 25 parts The dimensional change of the printed wiring board of Example 3 is shown in Table 1. Shown in.

Example 4 The glass fiber woven fabric woven in Example 2 was used, and Example 3 was used.
A copper clad laminate was obtained in the same manner as. Table 1 shows the amount of dimensional change of the printed wiring board of Example 4.

Comparative Example 2 Using the glass fiber woven fabric woven in Comparative Example 1, Example 3
A copper clad laminate was obtained in the same manner as. Table 1 shows the amount of dimensional change of the printed wiring board of Example 2.

[Advantages of the Invention] The glass fiber woven fabric-reinforced printed wiring board according to the present invention is formed by using the glass fiber woven fabric of nanako woven fabric as a base material as described above, and therefore is not excellent in conventional printed wiring boards. Has dimensional stability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a structural diagram showing an example of the structure of a glass fiber woven fabric used as a base material for a glass fiber woven fabric reinforced printed wiring board according to the present invention. FIG. 1A is a 2/2 Nanako weave. , Fig. 1B is 3/3
FIG. 2 is a plan view of the laminated board showing the size of the laminated board for measuring dimensional stability and the position of the reference point. 1 ... Laminated plate for dimensional stability measurement, 2 ... Gage mark.

Claims (1)

(57) [Claims] 1. A laminated board formed by laminating and molding a plurality of glass fiber woven fabrics using a thermosetting resin as a binder, wherein the glass fiber woven fabric is capable of simultaneously floating and sinking two or more and five or less warps and wefts at the same time. It is a glass fiber woven fabric reinforced printed wiring board characterized by being constituted by a woven fabric.