JPS6227757B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a printed wiring board having first and second wiring patterns formed in first and second different processing steps on the outer surface of the board to which a large number of electronic components are attached. Concerning the manufacturing method.

A conventional method for manufacturing a printed wiring board will be explained with reference to FIG.

In the figure, reference numeral 1 denotes a substrate, and as shown in FIG.
A copper film 5 is formed on the outer surface of the substrate 1, which covers the entire outer surface of the substrate 1, which is formed by chemical copper plating and electrolytic copper plating, as shown in FIG.

Reference numeral 6 denotes a first mask, which coats a photosensitive agent on both the front and back sides of the substrate 1 and exposes it from the outside through a first film on which a first pattern is printed, as shown in FIG. As a result, the portions other than the first pattern are exposed to light and the plating prevention film is denatured, and the non-exposed portions within the first pattern are removed with a solvent.

Reference numeral 7 denotes a first wiring, which is formed by performing a first plating process using a first metal material on the outer surface of the substrate 1 on which the first mask 6 is attached. It is formed by fixing one metal material in a first pattern shape. After this first wiring 7 is fixed on the substrate 1, the first mask 6 is removed with a solvent to protrude from the surface of the substrate 1, and the wirings in the first wiring 7 that need to be insulated from each other are removed. By etching and removing the copper film 5 between the first wirings 7, first wirings 7 capable of transmitting a predetermined current to each electronic component electrically connected to each part of the surface of the first wirings 7 are formed. It is possible to do so.

As described above, in the conventional printed wiring board, the first metal material having the same composition is used in all parts on the surface of the substrate 1, and the first metal material is formed by a single first plating process. It was formed by depositing a patterned first wiring 7.

For this reason, when the surface area of the substrate 1 is large and the first pattern has a shape that extends over a wide range, there will be variations in the thickness of each part of the first wiring 7. It was difficult to form the first wiring 7 having the above-mentioned structure.

Furthermore, if the desired first pattern requires a complicated shape, mismatches may occur between each portion of the first wiring 7 and the predetermined first pattern, resulting in errors between the parts. Since the dimensions varied greatly in each part of the wide substrate 1, it was difficult to form the first wiring 7 having a complicated shape with high dimensional accuracy.

Furthermore, during the first plating process, it was not possible to change the energization time depending on the different parts of the first wiring 7, so the wall thickness of only specific parts of the first wiring 7 could be reduced. It was not possible to form a different first wiring 7.

Conventional printed wiring boards were subject to these manufacturing constraints, so the first wiring 7 required a complex shape.
could not be formed with high dimensional accuracy.

Furthermore, since all parts of the conventional first wiring 7 were formed of the same first metal material, it is possible to make only a specific part of the first wiring 7 contain a component different from the first metal material. However, it was not possible to give different material properties to specific parts.

Conventional printed wiring boards use the same metal material over the entire surface of the wiring, and are uniformly plated everywhere, making it possible to form wiring with complex shapes with high precision. The disadvantage is that it is difficult to control the wiring, and it is impossible to make different material functions exhibit at different locations in the wiring.

This invention was made to eliminate the above-mentioned drawbacks of the conventional printed wiring board manufacturing method, and includes:
A second plating process is performed using a second metal material on a part of the board to which the first wiring formed by performing the first plating process using the first metal material is adhered to the outer surface of the board. Printed wiring that allows wiring with complex shapes to be formed with high precision by applying a plating process and attaching the second wiring, and that exhibits different material characteristics in different parts of the wiring. The purpose is to provide the following.

An embodiment of the present invention will be described below with reference to FIG.

In the figure, 1 to 7 are the same as the conventional symbols.

Reference numeral 8 denotes a second mask, which is a second film on which a photosensitive agent is applied covering both the front and back surfaces of the substrate 1 and the outer surface of the first wiring 7, and a second pattern is printed from the outside. By exposing the film to light through the plating film, parts other than the second pattern are exposed to light and transformed into a plating prevention film, and the non-exposed parts within the second pattern are removed with a bath agent to form the film.

Reference numeral 9 denotes a second wiring, which is formed by applying a second plating process using a second metal material to the outer surface of the substrate 1 on which the second mask 8 is attached. It is formed by fixing two metal materials in a second pattern shape. After this second wiring 9 is fixed, the second mask 8 is removed with a solvent, and the unnecessary portions of the copper coating 5 between the second wiring 9 and the first wiring 7 are removed. A printed wiring board can be formed in which the first wiring 7 having the first pattern shape and the second wiring 9 having the second pattern shape are exposed on the surface of the substrate 1.

This printed wiring board is manufactured by dividing all the wiring on the board 1 into the first pattern and the second pattern as described above, and applying the first plating process using the first metal material and the second plating process using the first metal material, respectively. By performing the plating process twice, including the second plating process using the metal material, a wiring having a shape that is a combination of the first and second patterns is formed.

Therefore, if the wiring shape is complicated, it can be divided into a simpler first pattern and a second pattern to more easily form the first and second wirings 7 and 9 with accurate shapes. By doing this, the disadvantage of conventional printed wiring boards that it was difficult to produce wiring with high dimensional accuracy has been improved, and it is now possible to form the first and second composite wiring with high dimensional accuracy even if the shape is complex. This is possible.

For example, with the conventional method, a pattern position accuracy of only about ±0.1 mm could be obtained, but with the present invention, a pattern position accuracy of about ±0.05 mm could be obtained. In addition, regarding the uniformity of plating (variation range), the conventional method was 20 to 50 μm, but in this invention, it was 5 to 50 μm.
A sample with a diameter of 15 μm was obtained.

In addition, if a thin part and a thick part are required in the wiring, these are divided into first and second patterns, respectively, and the first and second metal materials are made of the same metal material, for example. By using copper and changing the energization time to short and long times during the first and second plating processes, we have overcome the drawback that conventional wiring could not be formed with different wall thicknesses at specific points. By removing it, it is possible to form a composite wiring having a different thickness only at the required locations.

Furthermore, if it becomes necessary to change the material characteristics of the wiring depending on the position on the substrate 1, for example, if copper wiring has a problem and silver wiring is required in a specific part, the copper wiring part should be changed first. As a pattern, a first plating process is performed using copper as the first metal material, and a part requiring silver wiring is divided as a second pattern, and a second plating process is performed using silver as the second metal. By applying the treatment, the disadvantage of conventional methods where the constituent metal components could not be changed depending on the position within the wiring is eliminated, and copper and silver, which shine with the different material functions of silver wiring, are used in specific parts of the wiring. This makes it possible to form composite wiring.

Although the above explanation has been made using the case where all the wiring on the board is divided into two types of wiring, the first and second types, the number of divisions is not limited to just two types. Furthermore, it can be divided and formed into various types of wiring.

For example, in another embodiment shown in FIG. 6, copper and copper are used as the first, second, and third metal materials, respectively.
This figure shows a printed wiring board having tricomposite wiring of copper, silver, and gold formed by performing first, second, and third plating treatments using silver and gold, respectively. The gold wiring, which is the third wiring 10, is made by applying a photosensitive agent to the outer surface of the substrate 1 on which the first copper wiring 7 and the second silver wiring 9 are formed, as shown in FIG. It is formed by performing a third plating process using a third mask 11 formed in a pattern shape.

Note that by making the shape of the third mask 11 such that a part of the first wiring 7 or the second wiring 9 is exposed, a part of the first or second wiring is exposed and other parts are exposed. A third wiring 12 or a third wiring 13 is formed to cover the wafer, and a superimposed wiring in which a portion of copper or silver is plated with gold is obtained, respectively.

In this way, by dividing all the wiring on the board into various types of wiring, this printed wiring board can not only precisely form wiring with complex shapes, but also by polymerizing different metal materials. This makes it possible to form overlapping wirings having various material functions, and any of them can produce the same effects as described above.

The present invention provides a first wiring formed by performing a first plating process using a first metal material on a part of the outer surface of the board as described above, on a part of the board, Since the second metal material is used to perform the second plating process to adhere the second wiring, it is possible not only to form wiring with a complex shape with high precision, but also to prevent This has the effect of providing a printed wiring board that exhibits different material characteristics in different parts.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the structure of a conventional printed wiring board, Figs. 2 to 4 are explanatory views explaining the manufacturing process of Fig. 1, and Fig. 5 shows the structure of an embodiment of the present invention. 6 is a sectional view of another embodiment shown in FIG. 5, and FIG. 7 is an explanatory view explaining the manufacturing process of FIG. 5. In the figure, 1 is a substrate, 2 is an insulating plate, 7 is a first wiring, and 9 is a second wiring. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A first step of applying a first plating process to an insulating substrate using a first metal material to form a first wiring pattern; a second step of applying a second plating treatment to a part of the surface of the insulating substrate on which the first wiring pattern is formed using a second metal material to form a second wiring pattern; A method for manufacturing a printed wiring board. 2. Claim 1, characterized in that the first metal material and the second metal material are formed using exactly the same metal components but with different wall thicknesses, or using mutually different metal components. A method of manufacturing the printed wiring board described. 3. Claim 1, characterized in that the second wiring pattern is formed by a plating process using a photographic method in which a photosensitive agent is applied to the outer surface of the substrate and then exposed and developed. A method of manufacturing the printed wiring board described.