JPH05169582A - Production of laminated sheet - Google Patents

Abstract

PURPOSE:To provide a laminated sheet reduced in the variation of a dimensional change ratio and optimum for production of a fine-pattern printed wiring board by using specific glass cloth for the warp and weft yarns thereof, impregnating the same with thermosetting resin varnish such as epoxy resin varnish to obtain a prepreg and laminating a number of the prepregs after drying. CONSTITUTION:Glass cloth whose tensile strength in a 40 deg. direction for the warp and weft yarns thereof is 30kg/25mm or more is used. This cloth is impregnated with epoxy resin varnish consisting of an epoxy resin, a curing agent dicyandiamide, a curing accelerator 2-ethyl-4-methylimidazole and a solvent, and the impregnated one is dried to obtain a prepreg. A number of the prepregs are laminated and copper foils are superposed on both surfaces of the laminate and the whole is molded under heating and pressure to obtain a laminated sheet. By this method, the laminated sheet excellent in dimensional stability can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a printed circuit board having excellent dimensional stability.

[0002]

2. Description of the Related Art An arbitrary number of prepregs obtained by impregnating a fiber base material with a thermosetting resin such as an epoxy resin and drying it are laminated,
Thermosetting resin copper clad laminates formed by heat and pressure molding are mainly used as printed wiring board materials for industrial electronic devices and OA devices. The required properties for this laminated plate are also becoming more diverse. In recent years, along with miniaturization and refinement in the electric and electronic fields, there has been an increasing demand for higher density of printed wiring boards, and the demand for dimensional stability of laminated boards has become stronger and stronger. For dimensional stability,
There are two requirements, one is the minimization of shrinkage rate, and the other is the minimization of its variation. However, if a scale factor can be applied when making a negative for solder resist printing The magnitude of dimensional shrinkage does not matter, but the variation in shrinkage rate becomes a problem.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been made as a result of various studies in order to solve the problem of the conventional variation in the dimensional shrinkage ratio, and the object is to obtain the variation in the dimensional shrinkage ratio. It is an object of the present invention to provide a copper clad laminate which is extremely small and therefore has excellent dimensional stability.

[0004]

According to the present invention, the tensile strength in the direction of 45 ° is 30 kg / 25 with respect to the warp and weft of the cloth.
A method for producing a laminated plate, comprising using a glass cloth having a size of not less than mm, impregnating and drying a thermosetting resin varnish such as an epoxy resin to obtain a prepreg, and laminating and molding a predetermined number of the prepreg.

The present invention will be described in detail below. In general,
In the coating step in which a glass cloth is impregnated with a thermosetting resin varnish such as an epoxy resin and dried, the prepreg obtained has bending of the cloth. This bending is formed as it is as a laminated plate. The bends left on the laminated plate bring the directional property to the contraction of the laminated plate when heat treatment or the like is performed. The direction of this contraction is due to the vertical deformation of the cloth. That is, this deformation causes variations in shrinkage of the laminated plate.

The present invention is applied to 45 warps and wefts of cloth.
By using a glass cloth that has a tensile strength of 30kg / 25mm or more, it is possible to suppress the bending of the cloth when it is applied and to further improve the correction of the bending when the resin melts during pressing. Therefore, due to these two effects, it is possible to minimize the variation in the dimensional shrinkage ratio of the laminated plate. The thermosetting resin used in the present invention includes polyimide resin, phenol resin, polyester resin and the like in addition to epoxy resin, and is not particularly limited.

[0007]

【Example】

[Example 1] A glass cloth (Cross A) having a tensile strength in the direction of 45 ° of 35.2 kg / 25 mm with respect to the warp and weft of the cloth is used, and an epoxy resin (made by Yuka Shell Epoxy Resin Co., Ltd.) is used. EP-5045) 100 parts by weight (hereinafter referred to as "part"), curing agent dicyandiamide 4.7 parts, curing accelerator
An epoxy resin varnish consisting of 2-ethyl-4-methylimidazole and a solvent was impregnated and dried to obtain a prepreg.
Eight layers of this prepreg are laminated to form copper foil (18 μm) on both sides.
Were stacked and subjected to heat and pressure molding to obtain an epoxy resin copper clad laminate having a plate thickness of 1.6 mm. The dimensional change rate of this copper clad laminate was measured. [Example 2] A laminated plate was obtained in the same manner as in Example 1 using a glass cloth (cloth B) having a tensile strength in the 45 ° direction of 32.8 kg / 25 mm with respect to the warp and weft of the cloth.
The dimensional change rate was measured.

[Comparative Example 1] For warp and weft of cloth,
Using a glass cloth (cloth C) having a tensile strength in the 45 ° direction of 6.8 kg / 25 mm, a laminated plate was obtained in the same manner as in Example 1 and the dimensional change rate was measured. [Comparative Example 2] A laminated plate was obtained in the same manner as in Example 1 using a glass cloth (Cross D) having a tensile strength in the 45 ° direction of 9.6 kg / 25 mm with respect to the warp and weft of the cloth. The rate of change was measured. Table 1 shows the dimensional change rates and their variations in these examples and comparative examples.

[0009]

[Table 1]

(Note 1) Method of measuring the rate of dimensional change A copper-clad laminated board of metric square is 330 × 33 as shown in FIG.
Cut into 0 mm size to obtain 9 test pieces. Two holes (a, b, c, d, 2 points) in each of the longitudinal direction and the weft direction of each test piece.
A total of 4 points are opened, and the distance (A) between the holes is measured from the coordinates of each hole. Next, the entire surface of the copper foil is etched to 180 ° C.,
The distance (B) between the holes after heat treatment for 30 minutes is measured.
Then, the dimensional change rate is calculated by {(B−A) / (A)} × 100 (%).

[0011]

EFFECTS OF THE INVENTION The thermosetting resin copper clad laminate obtained by the present invention has extremely small dimensional stability, especially variation in dimensional change rate, as compared with the conventional laminate, and therefore the scale factor value can be easily predicted. Therefore, it is suitable for manufacturing printed wiring boards for fine patterns.

[Brief description of drawings]

FIG. 1 is a plan view of a test piece for measuring a dimensional change rate.

[Explanation of symbols]

 1 to 9 test piece a to d dimension measurement hole

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H05K 1/03 K 7011-4E

Claims (1)

[Claims] 1. A prepreg is obtained by using a glass cloth having a tensile strength of 30 kg / 25 mm or more in the 45 ° direction with respect to the warp and weft of the cloth, impregnating and drying this with a thermosetting resin varnish such as an epoxy resin. A method for producing a laminated board, which comprises obtaining and laminating a predetermined number of the obtained sheets.