JPH033393A - Manufacture of copper-plated laminated board - Google Patents

Abstract

PURPOSE:To reduce the error of the position of an inner layer circuit generated when an inner layer circuit board is introduced between prepregs to heat and pressurize it by forming the width of a groove formed on the periphery of the board to a specific size or less and forming the outer periphery of the groove in the same plane state. CONSTITUTION:The width 5 of the groove 2 of the periphery of a circuit pattern 1 is formed to 5mm or less, a laminate formed by superposing a copper foil on the surface of an inner layer circuit board 6 through a prepreg is interposed to be held between stainless steel plates, heated and pressurized. Numeral 4 denotes a guide hole 4 for processing. Since a conventional air vent groove 3 is eliminated and the width of the peripheral groove of an inner layer circuit forming part is narrowed, the flowing resistance of prepreg resin is larger than a conventional one. Accordingly, variation in the inner layer circuit position before and after the layer is formed is reduced, and conventional voids are eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a manufacturing method for improving the dimensional accuracy of the inner layer circuit of a copper-clad laminate for a multilayer printed board by C degree.

[Conventional technology]

The steel foil N board for multilayer printed boards uses one or more copper-clad laminates with all circuits formed for the inner layer, prepreg is arranged between the steel foil for the outer layer and the inner layer circuit board, and Manufactured by heating and press forming using stainless steel plate equipment. that time,
A void, that is, a gap in which the resin is not exposed to light, may be formed between the inner layer circuit and the inner layer circuit where the copper foil is removed by etching. Normally, in order to prevent this void from occurring, the T
- Provide an extraction groove.

Recently, multi-layer printed circuit boards are becoming more densely packed with single wiring lines and small through-holes formed by drilling small diameter holes. Therefore, the accuracy of the inner layer circuit is becoming increasingly strict. For example, if a through hole is formed in a grid of 2°54 mm with a drill of 10 mm diameter, and there are 1 or 2 line wirings between the grids, the positional accuracy of the inner layer (9) is ±200.
±250 μm root depth and light minutes. However, it is necessary to use a small diameter drill (Q, 2 to CL4IXlfflφ) to drill a printed board with an I% electrical variation of ±150 μm or less.

[The problem that the invention attempts to solve]

Under the above circumstances, the misalignment of the inner layer circuit is largely caused by heating and pressure during lamination and molding of copper-clad laminates for multilayer printed boards. When the inner circuit board is placed between the prepregs and heated and pressurized, the resin of the prepreg (X, Y) is applied to the inner layer circuit board in order to melt and flow.
A directional force acts. Furthermore, since the temperature becomes higher than the thermal deformation temperature of the base resin of the inner layer circuit board due to heating, the force caused by the flow causes deformation. Furthermore, the stability of the inner layer circuit decreases due to expansion and contraction due to heating and cooling.

It is an object of the present invention to solve these problems and provide a method for manufacturing a steel eroded laminate for printed boards with high 11 precision.

[Means to resolve the problem]

As a result of studying a method with high precision for the position of the inner no circuit, the present invention has been developed to improve the position accuracy of the inner no circuit and the method of opening the air vent groove, which was conventionally provided for plaster molding, and the position accuracy of the inner no circuit. The method of the present invention has been found to be
This is a manufacturing method in which the inner layer circuit board is sandwiched between laminated fake stainless steel plates made by layering copper foil via prepreg on the surface of an inner layer circuit board having a thickness of less than m, and then heating and pressurizing the board.

Next, the present invention will be explained with reference to the drawings. FIG. 2 shows an inner J-circuit board provided with a conventional air vent groove. The final printed board! There are a W1 circuit forming part 7, an inner retaining circuit forming part circumferential groove 2, an air vent groove 3, and a kite hole 4 for processing. 1st
Although the figure shows the circuit board of the present invention, the inner layer IP! Either the circuit forming part periphery 42 is provided or no air vent groove is provided.

[Effect]

According to the method of the present invention, since the width of the inner J/(B) tract forming part chest girth groove is narrowed except for the air handling groove, the flow resistance of the prepreg resin is greater than before, and therefore the inner Jll11 circuit position before and after N4N molding is It is thought that there is little change in . Further, according to the invention, voids do not occur as in the conventional pfQ method.

〔Example〕

The prepreg and copper foil were applied to the inner layer LgI board without air pressure and pressure shown in FIG. 1, and heated and pressed in a conventional manner to obtain a copper-clad IjI laminate for a multilayer printed board. At this time, -t5 chick, lQmo, 2 of the groove around the inner layer circuit forming part of the inner layer circuit board.
It was set as 3s for 0 city.

[Comparative example]

The inner layer I has a conventional air handling m shown in FIG. 2 and has a groove around the inner layer circuit forming part with a width of 5 cm! ll! A copper-clad laminate for a multilayer printed board was obtained using the same method as in the example using a road board.

Table 1 shows the amount of change in the inner layer circuit potential after lamination molding in the J-plates obtained in the above Example and Comparison 9.

Table 1 [Effects of the invention] According to the present invention, details 1 of the @stretched laminate for multilayer printed boards
Maximum change in inner layer circuit position after ml molding is 100μm
It is now possible to manufacture the following:

[Brief explanation of drawings]

Fig. 1 shows an uninvented inner layer circuit board, and Fig. 2 shows a conventional inner layer circuit board. 1... Inner layer (b) path forming part, 2... Inner layer circuit type H. Miyako area ditch, 3...
・Air release skin, 4...Guide hole for processing, 5
...Whirlpool City, 6...Inner layer circuit board.

Claims (1)

[Claims] 1. A groove with a width of 5 mm or less is provided around the circuit pattern, and the outer periphery of the inner layer circuit board is made flush with the surface of the inner layer circuit board. A method for manufacturing a copper-clad laminate for a multilayer printed board, which comprises sandwiching a laminate structure made by stacking the laminates between stainless steel plates and molding them by heating and pressing.