JPS59207696A - Method of producing multilayer printed circuit 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] [Field of Application of the Invention] The present invention relates to a method for manufacturing a multilayer printed wiring board, and in particular, to a multilayer printed wiring board suitable for controlling variations in dimensional change of a woven fabric base material in a lamination bonding process. Concerning a chemical molding method.

[Background of the invention]

Conventionally, multilayer molding in the manufacturing method of multilayer printed wiring boards involves the use of adhesive sheets made of resin-impregnated woven fabric substrates as well as laminates with conductor circuits formed on the surface of resin-impregnated woven fabric substrates in advance. A common method is to alternately stack and heat and pressurize. Furthermore, in order to mutually align the multiple laminated plates (hereinafter referred to as "inner layer materials") to be laminated, multiple guide holes were prepared in advance around the inner layer materials, and dowel pins were inserted into the holes. A common method is to perform multilayer molding. In recent years, in high-density multilayer printed wiring boards, the thickness of the laminated inner layer materials has become extremely thin, and as a result, the variation in dimensional changes of the inner layer materials during the multilayer forming process is rapidly increasing. A problem has arisen. The variation in dimensional changes in the inner layer material during the multilayer molding process is the result of a complex interaction of factors such as the flow of the resin in the adhesive sheet and shrinkage during curing, as well as the softening and deformation of the inner layer material due to heating and pressure. It is thought that these effects become larger as the thickness of the inner layer material becomes thinner, but the process by which this occurs is not yet clear. When the variation in dimensional changes increases, the mutual positional deviation of the conductor circuits formed on the surface of the inner layer material becomes large, and the mutual positional deviation with the through holes formed after multilayer molding occurs, which is fatal for multilayer printed wiring boards. inner layer.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a multilayer molding method capable of controlling variations in dimensional changes of inner layer materials in order to eliminate the above-mentioned problems.

[Summary of the invention]

As a result of a detailed analysis of the form of dimensional changes in the thin inner layer material during multilayer molding, the present inventors found that strain and deformation of the inner layer material have a large contribution rate to variations in dimensional change. It was discovered that there is a correlation between the weaving direction of the woven fabric base material that makes up the material. That is, the weft direction of the woven fabric base material is looser than the warp direction, so it is more likely to shift, and this is due to resin flow, curing shrinkage, heating, and
It has become clear that the influence of pressurization, etc. is large, and strain and deformation are likely to occur. Furthermore, it has been found that this strain and deformation can be controlled through guide holes and guide bins for positioning the inner layer material, leading to the present invention. That is, the present invention provides at least three or more guide holes on one side in advance along the side perpendicular to the weft of the woven fabric base material of the inner layer material, and inserts matching bottles into the guide holes to perform multilayer molding. , to restrict strain and deformation of the inner layer material in the weft direction.

[Embodiments of the invention]

Examples of the present invention will be described below with reference to figures and tables. 1st
The figure shows a typical example of the strain and deformation of the inner layer material that occurs during the multilayer molding process. It can be seen that both of these results are due to the "shift" of the inner layer material in the weft direction shown by the arrow.

In order to confirm the relationship between the strain and deformation described above and the arrangement of guide holes in the inner layer material, the inventors investigated dimensional changes in the inner layer material having three types of guide holes as shown in the figure. In the case of FIG. 2 and (21), the strain and deformation shown in FIG. 1 were observed, whereas in the case of %(22)-(2-3), a similar strain and deformation regulating effect was confirmed. Table 1 shows the experimental results for two types of inner layer material thicknesses, comparing the variation in dimensional changes and I7.

Table 1 However, if the rot is 1 term 0.2 and the wealth is wood, it is set as 100.

The thinner the inner layer material is, the larger the variation in dimensional change becomes.For any thickness, by arranging the guide holes in the arrangement (42, 3) of the present invention, the strain and deformation of the inner layer material can be reduced. It can be seen that the variation in dimensional and dimensional changes becomes smaller.

〔Effect of the invention〕

As shown in the examples above, according to the present invention, it is possible to control the occurrence of strain and deformation of the inner layer material during multilayer molding, and as a result, it is possible to achieve the effect of reducing the variation in dimensional changes of the inner layer material. .

Therefore, it is possible to perform multilayer molding with high precision using thinner inner layer materials than before, and it is possible to obtain a multilayer printed wiring board with higher density and higher multilayers at a higher yield.

[Brief explanation of the drawing]

Figure 1 shows the strain that occurs during multilayer molding of thin inner layer materials.
FIG. 2 is an explanatory diagram showing a modified form, and is a schematic diagram showing an arrangement of guide holes for confirming the effects of the present invention. 1...Inner layer material, 2...Guide hole. Representative Patent Attorney Akio Takahashi No. 7 Figure 7 Figure 2/ (/-3> (2-3) 465-

Claims (1)

[Claims] 1. A laminated board with a conductive circuit pattern formed on one or both sides of an insulating board made by impregnating and curing a resin into a woven fabric base material, and an adhesive sheet made by impregnating a woven fabric base material with a resin and semi-curing them together using pins. In the method for producing a multilayer printed wiring board, which comprises the steps of stacking the woven fabric substrate alternately through the woven fabric substrate, heating and pressurizing the woven fabric substrate to form a multilayer structure, and then forming holes, plating, and forming a conductor circuit button on the woven fabric substrate. Manufacture of a multilayer printed wiring board characterized in that at least three or more guide holes are provided on one side in advance along the side perpendicular to the weft of the material, and multilayer molding is performed by inserting dowel pins into the guide holes. Method.