JPS62162533A - Single-sided metal-lined laminated board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field J] The present invention is directed to the prevention of warping, twisting, and
The present invention relates to a single-sided metal-clad laminate that has a reduced dimensional change rate, etc., and has improved reliability during commercial density mounting of the laminate.

[Background technology j] In manufacturing a laminate, a plurality of prepregs 1 formed by impregnating a base material with resin and drying are stacked as shown in Fig. 2, and a copper foil is coated on the surface of the laminate 2. The laminate 2 and the metal M3 are bonded together and manufactured by stacking and molding the metal M3 such as the above, but when this laminate 4 is subsequently punched out, it may be difficult due to shear resistance, pull-out resistance, etc. , when the metal M3 side is the front surface as shown in FIG. 3, there is a defect α in which the central portion of the laminate 4 is warped toward the front surface.

Therefore, in the past, a method was considered to reduce the ratio of the base material to the resin of the prepreg 1 on the metal foil 3 side compared to the other parts of the prepreg 1, but in this method, the resin of the prepreg 1 on the metal foil 3 side Due to the increased amount, there were problems such as cracks occurring on the surface during punching, especially in areas with a large number of small holes, as well as a decrease in mechanical strength. In addition, as a method to solve problems such as warpage of the laminate 4, the ratio of the base material and resin in each prepreg 1 is made the same, but as the base material of the prepreg 1 on the metal 13 side, the base material is the same as that of the metal M3. There is a method to solve this problem by using a base material that shrinks more when heated than the base material of the prepreg 1 on the side. For example, a method is to use linter paper, which is easily shrunk, as the base material for the prepreg 1 on the metal foil 3 side, and to use kraft paper as the base material for the other prepregs 1. However, this method has the disadvantage that since a different base material is included in the same structure, twisting or the like occurs in the laminate 4, resulting in a large dimensional change rate.

[Objective of the Invention J The present invention has been made in view of the above-mentioned points, and is a method for reducing the workability, bending strength, etc. of warpage, twisting, dimensional change rate, etc. of the laminate during the processing process of the laminate. It is an object of the present invention to provide a single-sided metal-clad laminate that can be made smaller without causing problems.

[Disclosure of the Invention] That is, the single-sided metal-clad laminate according to the present invention is produced by laminating a plurality of prepregs 1 formed by impregnating a base material with a resin and then drying the same, and also coating the surface of this laminate 2 with metal foil. 3, laminate 2 and metal i! It is a laminate board characterized by integrally laminating and molding F3, and the ratio of the base material to the resin of the prepreg 1c on the side opposite to the metal foil 3 is the resin of the prepreg 1 at 1b on the side of the metal foil 3. Metal foil 3
The above object was achieved by increasing the ratio of the base material to the resin of the prepreg 1c on the opposite side.

The present invention will be explained in detail below. As the base material, paper, glass fiber, organic fiber, or a mixture thereof can be used, and as the resin, thermosetting resin such as epoxy resin or phenol resin can be used. After the base material is impregnated with the resin, it is dried to form a prepreg 1 of a predetermined thickness, and as shown in FIG. 1
1. ．． Load M3, then laminate 2 and metal? i3 is heated and pressurized to be integrally bonded and molded. here,
Weight ratio of base material and resin for each prepreg 1 (base material/resin)
can be set to about 0.90 to 1.30, but especially the prepreg 1 on the side opposite to the metal M3
The weight ratio of the base material and resin (base material/resin) of c is set to be larger than the ratio of the base material and resin (base material/resin) of the prepreg 1b of the intermediate layer and the prepreg 1a of the metal foil 3 side. For example, it is good to set it larger by 2 to 30%, preferably 3 to 15%. If this ratio is less than 2%, the effect of reducing warping, etc. of the laminate 4 is small, and if the ratio exceeds 30%, warping, etc. will occur on the opposite side. It is.

Therefore, in the cured product of prepreg 1, the higher the ratio of resin to the base material, the more likely it is to shrink when heated.
By setting the ratio of the base material to the resin to be larger than the ratio of the base material to the resin of the prepregs la and lb of the other metal foils 3gA, the M-layer plate 4 is given a force to warp concavely toward the surface side. Therefore, when the laminated plate 4 formed in this manner is punched, it is possible to prevent the laminated plate 4 from warping toward the surface side as shown in FIG. 3. Furthermore, the amount of resin does not become abnormally large in the prepreg 1a on the metal foil 3 side of the laminate 4, and surface scratches do not occur in areas where small holes are concentrated during punching, or mechanical strength decreases. There is no problem with doing so.

The present invention will be specifically described below based on Examples and Comparative Examples.

Implementation and Comparative Examples As shown in Table 1, the ratio of the base material of the prepreg to the resin in each layer of the surface layer A, intermediate layer B, and back layer C was 0.8.
5 to 1.30, and the increase rate of the ratio of the C part to the ratio of the A and B parts was set to -15 to 35%, and a laminate was produced based on a conventional method.

Then, we measured the warpage of the laminate after punching (punching at 50°C) during the processing process, measured the torsion of the laminate during the processing process, and measured the dimensional change rate, occurrence of surface cracks, and bending strength. Each was measured. The dimensional change rate was determined by etching the entire surface of a 250 x 250 mm laminate and then heating it at 120°C for 15 minutes. The warping was determined by measuring the maximum lifting amount at the four corners of a 2401 x 195 x 1111 x laminate. did.

In addition, as for the base materials used, linter paper was used for the surface layer of Comparative Example 2, kraft paper was used for all other parts, and plasticized phenolic resin was used as the resin. From the results in Table 1, The ratio of part C to parts A and B is 2
It was confirmed that the laminates 4 of Examples 1 to 5 with a concentration of 30% to 30% were satisfactory in terms of warping, torsion, dimensional change rate, occurrence of cracks, and bending strength. Incidentally, the increase rate of -15% described in Comparative Example 1 indicates the increase rate of the surface layer A with respect to the intermediate layer B and the back layer C.

[Effects of the Invention] As described above, in the present invention, the ratio of the base material to the resin of the prepreg on the side opposite to the metal foil is set to be larger than the ratio of the base material to the resin of the prepreg on the metal foil side. It is possible to reduce the warpage, twist, dimensional change rate, etc. of the laminate without reducing other punching workability or bending strength, and it is possible to significantly reduce NC) troubles in component mounting of laminates, increasing efficiency. This makes it possible to produce printed wiring boards with good quality and high reliability.

[Brief explanation of drawings]

FIG. 1 is an exploded cross-sectional view of one embodiment of the present invention, FIG. 2 is an exploded cross-sectional view of a conventional example, and FIG. 3 is an explanatory view showing the above problem. 1 is a prepreg, 2 is a laminate, 3 is a metal foil, and 4 is a laminate.

Claims (1)

[Claims] (1) After impregnating the base material with resin, multiple sheets of prepreg formed by drying are laminated, metal foil is placed on the surface of this laminate, and the laminate and metal foil are integrally laminated and molded. A single-sided metal-clad laminate consisting of a single-sided metal-clad laminate, characterized in that the ratio of the base material to the resin of the prepreg on the side opposite to the metal foil is set larger than the ratio of the base material to the resin of the prepreg on the metal foil side. Single-sided metal-clad laminate.