JPH04137694A - Manufacture of multilayer wiring board - Google Patents

Abstract

PURPOSE:To facilitate boring work or the like and obtain a multilayer wiring board with a wide area by using a single-sided copper clad resin laminated board as a board. CONSTITUTION:A single-sided resin laminated board clad with copper foil 3 on a single side of an insulation resin laminated board 2 is used as a board 1. A copper clad 3 portion, which is not covered, is removed by an etching solution where an etching resist is further removed, thereby forming a first wiring conductor 4. An insulation layer 5 including a platinum element is formed on the surface of the first wiring conductor 4 and the insulation resin laminated board 2. On the surface is laminated a resin layer 6. After the formation of the resin layer 6, a hole 17 which penetrate the board 1 is installed therein. A plating resist layer 8 is formed on a spot which excludes the formation of a second insulator on the surface of the resin layer 6. The resin layer 6 which is not covered with the plating resist layer 8, is surface-roughened. After the surface roughening, it is electroless copper-plated, thereby forming a second wiring conductor 9, which is connected with the first wiring conductor 4.

Description

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

(Prior Art) Conventionally, for example, a wiring conductor is formed on one side of an insulating substrate to form a printed wiring board, and electronic components are mounted on the surface of this printed wiring board.

An example is a thick film hybrid integrated circuit board in which alumina porcelain is used as an insulating substrate, wiring conductors and resistors are printed on the surface of the insulating substrate, and then fired.

(Problems to be Solved by the Invention) However, when ceramic such as alumina porcelain is used as an insulating substrate, it is difficult to manufacture a large-area substrate.

Therefore, a circuit that performs one function must be constructed from a large number of substrates, which has the drawback of making manufacturing difficult. Also, because it is hard, it is difficult to process such as drilling or cutting.

An object of the present invention is to improve the above-mentioned drawbacks, provide a method for manufacturing a multilayer wiring board that can have a large area, and is easy to manufacture.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for manufacturing a multilayer wiring board in which wiring conductors are formed in multiple layers on one side of a board, including: a) a single-sided copper-clad resin laminate; b) forming an insulating layer containing fine particles of a platinum group element; and c) forming holes or the surface of the insulating layer. d) forming a second wiring conductor on the surface of the insulating layer by electroless plating; The present invention provides a method for manufacturing a multilayer wiring board characterized by:

(Function) Because the board uses a single-sided copper-clad resin laminate, it is easier to process than ceramics such as alumina porcelain, and it is easy to drill holes, punch, and cut, making it easy to create large-area multilayer wiring boards. can be manufactured.

(Example) Hereinafter, the present invention will be explained based on examples.

As shown in FIG. 1, the substrate 1 is a single-sided copper-clad resin laminate in which a copper foil 3 is pasted on one side of an insulating resin laminate 2-. As this substrate 1, for example, a laminate plate (MCL-E67, manufactured by Hitachi Chemical Co., Ltd.) with a total thickness of 1.6 B and a thickness of 3 copper foils of 35 μm is used.

First, an etching resist is printed on the copper foil 3 to mask it, and then the portion of the copper foil 3 that is not covered with the etching resist is removed using an etching solution, and then the etching resist is removed, as shown in FIG. 1st
A wiring conductor 4 is formed. For example, a ferric chloride solution with a specific gravity of 40 Baumé is used as the etching solution.

After forming the first wiring conductor 4, as shown in FIG. 3, an insulating layer 5 containing fine particles of a platinum group element is formed on the surfaces of the first wiring conductor 4 and the insulating resin laminate 2.

For forming the insulating layer 5, for example, a platinum group element,
A viscous epoxy resin composition containing fine palladium powder that acts as a plating catalyst is applied to the entire surface of the substrate 1 using a stainless steel screen with a mesh size of 40. After coating, the insulating layer 5 is heated at a temperature of 150° C. for 60 minutes to form an insulating layer 5 with a thickness of 120 μm.

After forming the insulating layer 5, a resin layer 6 containing fine palladium powder is laminated on its surface, as shown in FIG. To form the resin layer 6, a resin containing fine palladium powder is applied by a curtain coating method and cured by heating at a temperature of 170° C. for 90 minutes to a thickness of 30 μm.

After forming the resin layer 6, a hole 7 passing through the substrate 1 is provided as shown in FIG. The hole 7 has a diameter of 0.5ffi1, for example.
Install using a drill of about 1 size.

After forming the holes 7, as shown in FIG. 6, a plating resist layer 8 is formed on the surface of the resin layer 6 at locations other than those where the second wiring conductor is to be formed. The plating resist layer 8 is formed, for example, by printing a viscous liquid of an epoxy resin by a screen printing method and heat-treating it at a temperature of 150° C. for 30 minutes.

After forming the plating resist layer 8, the resin layer 6 not covered by the plating resist layer 8 is roughened using, for example, chromic anhydride,! This is done by immersing the substrate 1 in a highly oxidizing solution consisting of acid and sodium fluoride.

After roughening, electroless copper plating is performed to form a second wiring conductor 9 as shown in FIG.
and the first wiring conductor 4 are connected.

The electroless copper plating solution used is one based on copper sulfate, EDTA, and formalin.

In the above embodiment, the plating resist layer 8 was formed after the holes 7 were formed, but on the contrary, the plating resist layer 8 was formed after the holes 7 were formed.
The hole 7 may be formed after forming the hole 7.

Further, the resin layer 6 may not be formed.

(Effects of the Invention) As described above, according to the manufacturing method of the present invention, since a single-sided copper-clad resin laminate is used as the substrate, it is easy to process wires, etc., and it is easy to manufacture large-area multilayer wiring boards. can be obtained.

[Brief explanation of the drawing]

1 to 7 show the manufacturing process of an embodiment of the present invention, FIG. 1 is a sectional view of the substrate, FIG. 2 is a sectional view of the substrate on which the first wiring conductor is formed, and FIG. 4 is a sectional view of a substrate on which a resin layer is formed; FIG. 5 is a sectional view of a substrate with holes formed thereon; FIG. 6 is a sectional view of a substrate on which a plating resist layer is formed; FIG. 7 shows a cross-sectional view of the substrate on which the second wiring conductor is formed. DESCRIPTION OF SYMBOLS 1... Substrate, 4... First wiring conductor, 5... Insulating layer, 6... Resin layer, 7... Hole, 8... Plating resist layer, 9... Second wiring conductor. Patent applicant Hitachi Capacitor Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] (1) A method for manufacturing a multilayer wiring board in which wiring conductors are formed in multiple layers on one side of a board, including the steps of: a) using a single-sided copper-clad resin laminate as the board and etching it to form a first wiring conductor; b) forming an insulating layer containing fine particles of a platinum group element, and c) forming holes or forming a plating resist layer on the surface of the insulating layer, one of which is performed first and the other after. and d) forming a second wiring conductor on the surface of the insulating layer by electroless plating.