JPH02194592A - Manufacture of multi-layer wiring board - Google Patents

Abstract

PURPOSE:To prevent warpage of an insulation substrate, thus reducing scattering of the thickness of an insulation layer and obtain a multi-layer wiring board without producing any crack in the insulation layer by forming the insulation layer, applying insulating ink onto both surfaces of the insulation substrate alternately. CONSTITUTION:A circuit 2 is formed by etching, for example, a copper foil of a copper-clad insulation substrate 1 and an insulating ink is applied to the entire surface of the insulation substrate 1. Furthermore, an insulating ink 4 is applied to the other surface of the insulation substrate 1 for curing. An insulating ink 5 is applied to the surface of the insulating ink 3 again for curing and forming an insulation layer 6. In similar manner, an insulation ink 7 is applied to the surface of the insulating ink 4 for curing and forming an insulation layer 8.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for manufacturing a multi-metal wiring board.

(Prior Art) Conventionally, a method for manufacturing a multi-metal wiring board involves using, for example, an insulating substrate with copper foil pasted thereon, applying etching to the surface of the copper foil, and then performing etching to form a circuit. After forming a circuit by etching, insulating ink is applied to one side by screen printing and hardened to form an insulating layer.

After forming an insulating layer on one side, an insulating ink having the same diameter is applied and cured on the other side to form an insulating layer.

(Problem to be solved by the invention) However, in the past, since the insulating layer was formed by applying insulating ink only once, the thickness of the application became thick, and the insulation after application When the adhesive ink is cured, there is a drawback that the insulating substrate is greatly warped. If the warpage of the insulating substrate becomes large, there is a drawback that the thickness of the insulating ink will not be uniform when applied to the other surface.

In order to prevent this drawback, there is a method of mechanically correcting the warpage of the insulating substrate after applying the insulating ink, but this method has the drawback of easily causing cracks in the insulating layer.

In order to achieve the above objects, an object of the present invention is to provide a multi-metal wiring board that can prevent large warping of an insulating substrate, make the coating thickness of insulating ink uniform, and prevent cracks from occurring in the insulating layer. A manufacturing method is provided.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention applies insulating ink alternately to both surfaces of an insulating substrate in multiple steps. The present invention provides a method for manufacturing a multi-metal wiring board, which is characterized in that an insulation diagram of a predetermined thickness is formed using eight cloths.

(Function) According to the present invention, after applying insulating ink to one side of the insulating substrate, insulating ink is applied to the other side, and insulating ink is applied again to the previous side, which is repeated as many times as necessary. , it is possible to form an absolute R layer with a predetermined thickness. Therefore, it is possible to reduce the amount of application friction of the insulating ink between the two times, and also to reduce the difference in the amount of application friction between both sides, thereby reducing warping of the insulating substrate.

(Example) The present invention will be explained below based on illustrated embodiments.

First, as shown in FIG. 1, a circuit 2 is formed by etching the copper foil of a copper-clad I8 edge board 1.

Next, as shown in FIG.
IT L hardens.

Furthermore, as shown in FIG. 3, an insulating ink 4 is applied to the other surface of the insulating substrate 1 and cured.

After applying the insulating ink 4, as shown in FIG. 4, an insulating ink 5 is again applied to the surface of the insulating ink 3 and cured to form an insulating layer 6. Similarly, as shown in FIG. 5, an insulating ink 7 is applied to the surface of the insulating ink 4 and cured to form an insulating layer 8.

Although the insulating layers 6 and 8 are formed by alternately applying insulating ink twice each, they may be formed by applying at least one of them two or more times.

For example, if one of the insulating layers can be formed by applying the insulating ink once, the other insulating layer can be formed by applying the insulating ink twice and curing it. Good too.

Further, both insulating layers may be formed by repeatedly applying insulating ink three or more times and curing it.

Next, regarding the embodiment of the present invention and the conventional example, the thickness is 200 μm.
After forming an insulating layer of m, the maximum and minimum thicknesses were measured. The manufacturing methods of the embodiment of the present invention and the conventional example are as follows.

Example of the present invention: As shown in Table 1, the insulating ink was applied twice by screen printing alternately, and after each application, it was dried for 60 minutes in an atmosphere at a temperature of 120°C. The insulation N is formed by drying and curing in an atmosphere at .degree. C. for 90 minutes.

In Table 1, insulating ink is applied, dried, and cured under the same conditions to form an insulation diagram.

The measurement results are shown in Table 2.

Table 2 Conventional example: Insulating ink was applied to one side of an insulating substrate to a thickness of 20 μm by screen printing using a 20-mesh plate. :;'z
It was dried for 60 minutes in an atmosphere at a temperature of 120° C. to harden it. Next, as is clear from Table 2, the range of the thickness of the insulating layer is -
9 to +7.5%, and -14.5-+13% for the conventional example, with the former having clearly less variation in thickness.

(Effects of the Invention) As described above, according to the manufacturing method of the present invention, since the insulating ink is applied alternately to both sides of the insulating substrate to form an insulating layer, warping of the insulating substrate can be prevented. As a result, variations in the thickness of the insulating layer can be reduced, and a multi-metal wiring board without cracks in the insulating layer can be obtained.

[Brief explanation of the drawing]

1 to 5 are cross-sectional views of a multimetallic wiring board showing the manufacturing process of the present invention. 1... Insulating substrate, 2... Circuit, 3.4. ．． 5.7... Insulating ink, 6.8... Insulating layer. Patent applicant Hitachi Capacitor Co., Ltd. 1 Figure 3, @5 Figure 2 Figure 4

Claims (1)

[Claims] (1) In a method for manufacturing a multi-metal wiring board in which an insulating layer is formed by applying insulating ink to the surface of an insulating substrate on which circuits are formed on both sides, insulating ink is applied alternately to both sides of the insulating substrate in multiple steps. 1. A method for manufacturing a multilayer wiring board, the method comprising: coating an insulating layer with a predetermined thickness.