JPH0356911B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a metal foil-clad laminate with excellent metal foil surface smoothness. Conventional technology Metal foil-clad laminates are made by laminating and molding prepreg obtained by impregnating and drying a sheet-like base material with thermosetting resin, with metal foil (18 to 35μ thick) placed on the surface. It has become. This laminated board is a circuit board with a wiring pattern formed by etching the metal foil on the surface, but as electronic devices become smaller and lighter, the wiring patterns are becoming finer. In order to form fine wiring patterns, etching is performed using UV-sensitive film. Problems to be Solved by the Invention By the way, in the metal foil-clad laminate described above, when glass fiber cloth is used as the base material in contact with the metal foil, the unevenness of the weave of the glass fiber cloth may appear on the metal foil. It will appear. As a result, the UV photosensitive film is unable to follow the unevenness, resulting in poor adhesion to the metal foil in the recessed areas.When the UV photosensitive film is etched after exposure, the etching solution seeps into the areas with poor adhesion, resulting in fine line patterns. wire breakage is likely to occur. The present invention provides a metal foil-clad laminate that uses glass fiber cloth as a base material at least in the position in contact with the metal foil, and has a metal foil-clad laminate that can improve the surface smoothness of the metal foil surface and can support the formation of fine line patterns. The purpose is to provide a board. Means for Solving the Problems In order to achieve the above object, the present invention provides a metal foil-clad laminate using glass fiber cloth as a base material at a position in contact with the metal foil, in which the cloth is configured as glass fiber cloth. The flatness of the warp and weft is 0.2~
0.13 plain weave glass fiber cloth is used. Function Usually, the glass fiber cloth used as a base material for metal foil-clad laminates is a plain weave, and the woven glass fiber cloth has a warp flatness of 0.23 to 0.25 and a weft flatness of 0.2 to 0.21. Yes, the flatness of the warp threads is smaller than that of the weft threads. On the other hand, the surface roughness of the laminate is
The vertical direction of the base material is smoother than the horizontal direction, and as a result of focusing on this fact and studying it, we found that the surface smoothness can be improved by changing the flatness of the threads that make up the glass fiber cloth. The flatness can be increased by defibrating the yarn. If the flatness is smaller than 0.2, the surface smoothness will not be improved enough, and if it is larger than 0.13, it will not be possible to defibrate and weave into glass fiber cloth, resulting in yarn breakage and fiber fuzz. . As shown in FIG. 1, the flatness is a cross section of a thread 2 formed by converging a large number of glass fibers 1, and is expressed by the short axis (B)/long axis (A). The smaller this value is, the greater the flatness is. Examples Examples of the present invention will be described. Examples 1 to 3, Comparative Examples 1 to 2 Bisphenol type epoxy resin (trade name Ep-
1001, manufactured by Yuka Shell, epoxy equivalent: 550) To 100 parts by weight, 4 parts by weight of dicyandiamide and 0.3 parts by weight of benzyldimethylamine were added to prepare a varnish,
This was impregnated into a plain-woven glass fiber cloth shown in Table 1 and dried to obtain a prepreg with a resin content of 40%. Eight sheets of this prepreg were stacked, 18 μm thick copper foil was placed on both sides, and molding was carried out at a molding pressure of 40 kg/cm ² and a molding temperature of 170° C. for 60 minutes to obtain a 1.6 mm thick copper clad laminate. Table 1 also shows the measured values of the surface roughness of the copper-clad laminate and the presence or absence of disconnection in the wiring pattern formed by etching. In the above embodiments, a predetermined plain-woven glass fiber cloth was used for all the base materials, but the center layer may be made of other base materials such as glass non-woven cloth.

[Table] Effects of the Invention As described above, according to the present invention, the flatness of the warp and weft of the plain-woven glass fiber cloth used in contact with the metal foil is set to 0.2 to 0.13, so that the flatness of the metal foil is The result is a metal foil-clad laminate with excellent surface smoothness. As a result, the adhesion between the UV-sensitive film and the metal foil is improved, and the industrial value is extremely high in that it is possible to reduce the disconnection defect rate when forming fine line patterns by etching.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the threads constituting the glass fiber cloth. 1 is glass fiber, 2 is thread.

Claims (1)

[Claims] 1 A laminate made by laminating and molding a prepreg obtained by impregnating and drying a thermosetting resin into a sheet-like base material and placing a metal foil on the surface, which has plain-woven glass fibers at least in a position in contact with the metal foil. 1. A metal foil-clad laminate using cloth as a base material, characterized in that the flatness of the warp and weft of the plain-woven glass fiber cloth is 0.2 to 0.13.