JPH04149246A - Production of laminated sheet - Google Patents

Abstract

PURPOSE:To obtain a laminate reduced in surface unevenness and coarseness by superposing plural sheets of a prepreg obtained by impregnating a specific glass cloth with a resin followed by drying and subjecting the superposed sheets to heating and pressurizing. CONSTITUTION:A glass cloth being <=3 in difference of numbers of weft and warp beaten of glass fiber per square inch and >=3 in flat degree of the glass fiber is impregnated with a resin and the treated glass cloth is dried to afford a prepreg and plural sheets of the prepreg are superposed, heated and pressurized to carry out laminate molding.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for manufacturing a laminate that is processed into a printed wiring board or the like.

[Conventional technology]

Laminated boards are made by using glass cloth as a base material and impregnating it with resin such as epoxy resin and drying it to create a prepreg, stacking multiple sheets of prepreg and, if necessary, adding metal foil such as copper foil to one side or the other. It can be manufactured by laminating the layers on both sides and applying heat and pressure.

[Problem to be solved by the invention]

However, with laminates manufactured using glass cloth as a base material, large undulations and surface roughness occur on the surface.
There has been a problem in that the yield rate is poor when forming circuit patterns on printed wiring boards. The present invention has been made in view of the above points, and it is an object of the present invention to provide a method for manufacturing a laminate that can reduce surface waviness and surface roughness.

[Means to solve the problem]

In the present invention, when producing a laminate by stacking a plurality of prepregs created by impregnating glass cloth with resin and drying them, heating and pressing them to form a laminate, the glass cloth can be used to produce a glass cloth per square inch. This method is characterized in that the difference in the numbers of warp and weft threads is set within 3, and a woven fabric is used that is made using glass threads with a flatness of 3 or more. The present invention will be explained in detail below. Glass cloth is made as a woven cloth by weaving a glass-based yarn prepared by bundling glass fiber filaments as warp and weft yarns. Here, as the glass cloth, the flatness of the glass thread is 3.
The one manufactured using the following F is used. Flatness is obtained as the value obtained by dividing the width of the glass thread by the thickness of the glass thread (thickness of the glass thread in the thickness direction of the glass cloth). The larger the numerical value of the thickness and flatness of the thread, the flatter the cross-sectional shape of the glass thread. The glass cloth used is woven with the number of warp and weft yarns set such that the difference in the number of warp and weft glass yarns per square inch is 3 or less. Incidentally, it is preferable that the glass cloth produced as described above is subjected to a fiber opening treatment. The opening process can be carried out by spraying high-pressure water onto the glass cloth or squeezing the glass cloth through a roll. Therefore, a prepreg can be created by impregnating the glass cloth prepared as described above with a varnish of a thermosetting resin such as an epoxy resin and drying it by heating. By stacking multiple sheets of this prepreg and, if necessary, layering metal foil such as copper foil on one or both sides, heating and pressurizing them to form a laminate, you can create a laminate with metal foil on one side or metal foil on both sides. 6 can be manufactured

[For use]

In the laminate manufactured as described above, the glass cloth constituting the base material is made of a material in which the difference in the number of glass threads per square inch between warp and weft is set to within 3. As a result, the expansion and contraction behavior of the glass cloth becomes uniform in both the vertical and horizontal directions of the laminate, which reduces the occurrence of surface waviness on the laminate, and In addition, because the glass yarn used to make up the glass cloth has a flatness of 3 or more, the unevenness caused by the intersection of warp and weft yarns on the surface of the glass cloth is reduced.
It is possible to reduce the occurrence of unevenness on the surface of the laminate due to the unevenness of the glass cloth.

【Example】

The present invention will be explained in detail below with reference to Examples. Inu iL palanquin ↓ Glass cloth 3 was made using glass thread with a flatness of 6 to 8, and the number of warp threads per square inch was set to 34, and the number of weft threads was set to 34. Glass cloth was opened by applying high-pressure water. Then, a prepreg was created by impregnating this glass cloth with epoxy resin varnish and heating and drying it. Seven sheets of this prepreg were stacked, and if necessary, three layers of copper foil with a thickness of 18 μm were stacked on both sides, and this was heated and pressed. By laminating and molding, a double-sided copper-clad plate with a thickness of 1.6 mm was obtained. A glass cloth was created using glass yarn with an flatness of 3 to 4, with the number of warp threads set to 34 and the number of weft threads set to 34, and the glass cloth was opened. It was used without fiber treatment, and a double-sided steel-clad laminate was obtained in the same manner as in Example M1. 2. Use a glass cloth made by setting the number of warp yarns to 36 and the number of weft yarns to 33 using glass thread (with a flatness of 6 to 8 g) and apply high pressure to this glass cloth. The fibers were opened by applying water, and the same machine as in Example 1 was used to obtain a double-sided copper-clad laminate. ! -1 Sen" A glass cloth was created using glass yarn with an oblateness of 6 to 8, and the number of warp yarns was set to 36 and the number of weft yarns was set to 33. This glass cloth was opened. It was used without treatment, and the rest was carried out in the same manner as in Example 1 to obtain a double-sided steel-clad laminate. 11 Salmon J- A glass cloth was created using glass yarn with a flatness of 3 to 4, with the number of warp threads set to 44 and the number of weft threads set to 32, and this glass cloth was subjected to high pressure. A double-sided copper-clad laminate was obtained in the same manner as in Example 1. 11: - Using glass cloth with a flatness of 1 to 2 and setting the number of warp yarns to 44 and the number of weft yarns to 32, this glass cloth was opened. It was used without treatment, and the rest was carried out in the same manner as in Example 1 to obtain a double-sided steel-clad laminate. Regarding the double-sided steel-clad laminate obtained as above,
The surface roughness of the surface (surface roughness in a direction diagonal to the longitudinal direction of the laminate) was measured, and the soldering heat resistance was measured at 260° C. for 20 seconds. The results are shown in the table below. As seen in the table, surface roughness can be reduced in each example.

【Effect of the invention】

As mentioned in L, in the present invention, the difference in the number of warp and weft of the glass yarn per square inch is set within 3, and the flatness of the glass yarn is set to 3 or less.
Since a woven fabric made using the above material is used, it is possible to reduce undulations and surface roughness on the surface of the laminate.

Claims (1)

[Claims] (1) When producing a laminate by stacking multiple sheets of prepreg created by impregnating glass cloth with resin and drying them, heating and pressurizing them to form a laminate, the glass cloth is used to produce a The production of a laminate, characterized in that the difference in the number of warps and wefts of the glass threads is set within 3, and the woven fabric is made using glass threads with a flatness of 3 or more. Method.