JPS5877292A - Method of producing 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] The present invention has a conductor network of a predetermined shape on both sides.

The present invention relates to a method for manufacturing a printed wiring board in which these conductor circuit networks are electrically connected by through-hole conductor paths,
The purpose is to provide a method for manufacturing printed wiring boards that can efficiently form plating layers for different uses for the conductor network.

Generally, the keyboard switch circuit and its peripheral circuits are
When integrated into a single printed wiring board, a double-sided printed wiring board is used, which has conductor networks of a predetermined shape on both sides of the printed wiring board and electrically connects these conductor networks with through-hole conductor paths. used. On double-sided printed wiring boards, the conductor circuit network for the switch circuit of the keyboard is often gold-plated as a contact plating, but copper plating is often applied as a through-hole conductor path. ν1. However, the different plating processes for double-sided printed circuit boards mentioned above are performed by placing a release paper, etc. in the areas where gold plating is to be formed, and then removing the release paper after applying a plating resist 11 to all of the ponds. Then, after removing the above-mentioned plating resist film, the surface on which the gold plating is to be formed is covered with a plating resist film, and then copper plating is performed, and finally the above-mentioned Since the plating resist film that improves the formation of gold plating must be removed, a copper plating layer will be provided on the conductor circuit network that has already been formed. There was a problem that a plating layer was formed. Therefore, if you try to form a copper plating layer only on the necessary parts of the conductor network that has already been formed, you will have to selectively apply the plating resist film, especially where the through-hole conductor path will be formed and where it will not be applied. When the formation locations are mixed, there is a problem in that the plating process becomes extremely troublesome.

The present invention solves these conventional drawbacks,
By selectively printing plating resist on the surface of the substrate body and the through holes at the same time, plating layers for different uses can be efficiently formed.

Examples of the present invention will be described below.

Example First, as shown in FIG. 1, a glass cloth base material epoxy resin is provided with a conductor layer (copper foil) 1.2 as a conductor network of a predetermined shape on both sides and a translucent T3 at a predetermined position. A printed circuit board 4 made of a laminated board was prepared. Next, as shown in FIG. 2, a metal mask 7 having a mask hole 6 and a stepped mask hole 6 is placed on one of the printed circuit boards 4 on which the conductor layer 1 is provided as a conductor circuit network. Plating resist 8 was printed using a screen printing method. At this time, as the plating resist 8, vinyl resin paint 206B manufactured by Nara Boots 1 was used after adjusting the viscosity to 20.0OOOPSK with a butyl carpitol solvent.

Through this screen printing, three-dimensional printing of the plating resist 8 is selected on the hole wall of the through hole 2 and the conductor layer 1 around the hole, which corresponds to the area where the through-hole conductor path is not formed, as shown in FIG. At the same time, planar markings 11111 of the plating resist 8 were selectively made on the conductor layer 1 corresponding to the locations where the gold plating was to be formed. Next, the printed circuit board 4'i is inverted, and a metal mask 11 having mask holes 9 and stepped mask holes 1o as shown in FIG.
was placed, and a plating resist 8 was printed using a screen printing method. By this screen printing, as shown in FIG. At the same time as printing was selectively performed, plating resist 8 was selectively printed on a plane on the conductor layer 2 corresponding to the areas where copper plating was not formed.Next, 1. The printed circuit board 4 was Put it in the oven and heat it to 120°C
After curing the printed layer of the plating resist 8 for 910 minutes, the plating is activated, and then immersed in a known copper plating solution to harden the printed layer of the plating resist 8 as shown in FIG. At the same time, a copper plating lip 12 is formed in a grommet shape on the hole wall of the through hole 2 corresponding to the unformed area and the conductor layer 1.2 around the hole, and at the same time, a plating resist 8 is formed.
A copper plating layer 12 was provided on the conductor layer 2 corresponding to the portion where the mark 1itl1 layer was not formed. After this plating treatment, the printed circuit board 4 was immersed in a 2% alkaline solution to peel off the printed layer of the plating resist 8. In this way, the first plating process for forming the copper plating layer 12 is completed. Next, as shown in FIG. 5, a metal mask 15 having a mask hole 13 and a stepped mask hole 14 is placed on one of the printed circuit boards 4 on which the conductor layer 1 is provided as a conductor circuit network. Plating resist 8 was printed using a screen printing method. By this screen printing, as shown in FIG. 5, the hole wall of the through hole 2 corresponding to the area where the through hole conductor path is not formed, the conductor layer 1 around the hole, and the copper plating layer 12 as the through hole conductor path are formed. A three-dimensional plating resist 8 is printed on each of the hole wall of the provided through hole 2 and the copper plating layer 12 around the hole, while at the same time leaving the conductor layer 1 corresponding to the area where the gold plating is planned to be formed. Plating resist 80 for all other conductor layers 1
乎+rri-like printing was performed selectively. Next, the printed circuit board 4 is turned over, and a metal mask having mask holes 16 and stepped mask holes 17 as shown in FIG. 18
was placed, and a plating resist 8 was printed using a screen printing method. By this screen printing, as shown in FIG. 6, the hole wall of the through hole 2 corresponding to the non-forming part of the through hole 10 and the conductor layer 2 around the hole. Three-dimensional printing of the plating resist 8 is performed on each of the hole wall of the through hole 2 provided with the copper plating layer 12 as a through-hole conductor path and the copper plating layer 12 around the hole, and at the same time, all other A plating resist 8 was printed flat on the conductor layer 2. Next, the printed circuit board 4 is placed in an electric furnace and the printed layer of the plating resist 8 is cured at 120°C for 9-10 minutes, and then the plating is activated, and then placed in a known gold plating solution. As shown in FIG. 7, a gold plating layer 19 was provided on the conductor layer 1 corresponding to the portion where the printed layer of the plating resist 8 was not formed.

After this plating process, the printed circuit board 4 is
% alkaline solution to peel off the printed layer of the plating resist 8. In this way, the second plating process for forming the gold plating layer 19 is completed.

In the above example, the entire printed layer of the plating resist 8 was removed at the end of the first plating process, but this was because the printed layer of the plating resist of the conductor layer 1 corresponding to the portion where the gold plating layer was to be formed was removed. In the second plating process, only the conductor layer 1 corresponding to the area where the gold plating layer is planned to be formed is left, and all other remaining areas are covered with a printed layer of the plating resist 8. .

Also, 1st. The order of the second plating process may be changed so that the copper plating process is performed after the gold plating process.

As described above, according to the present invention, the plating resist is printed simultaneously on the surface of the double-sided M11 wiring board and the through hole, so the printed layer of the plating resist can be selectively provided, and Plating and copper plating can be selectively formed only on necessary locations, and plating can be performed economically. This is advantageous because even if there are areas where through-hole conductor paths are formed and areas where they are not formed, a printed layer of plating resist can be selectively and easily formed.

This has the advantage that different plating layers can be provided only at necessary locations without complicating the plating process.

[Brief explanation of the drawing]

The drawings show an embodiment of the Jj method for manufacturing printed wiring boards of the present invention, in which FIG. 1 is a cross-sectional view of a double-sided printed circuit board as a starting material, and FIGS. 2 and 3 are cross-sectional views of a plating resist for copper plating. Printing process, 1G) Shikoku, Figure 4 is an explanatory diagram of the copper plating and resist removal process, Figures 5 and 6 are explanatory diagrams of the printing process of the plating resist for gold plating, and Figure 7
The figure is an explanatory diagram of the gold plating and resist removal process. 1.2...Conductor layer, 3...Through hole, 4.
...Printed circuit board%5,9,13.16...
...Mask hole, 6゜1.0, 14.17...Stepped mask hole, 7, 11゜15.18...Metal mask, 8...Plating resist , 12...
...Copper plating, 19...Gold plating. Name of agent: Patent attorney Masao Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] It has a printed circuit board having a conductive circuit network of a predetermined shape on both sides and a plurality of through holes in a predetermined position of the printed circuit board, and a plating resist is applied to a predetermined location of one of the conductor circuit networks and a predetermined location of the through holes of the printed circuit board. At the same time, a plating resist is simultaneously selectively printed at a predetermined location of the other conductor circuit of the printed circuit board and a predetermined location of the delivery hole, and after the plating resist is cured, the first A first plating process in which a first metal plating layer is deposited in a plating solution, and a plating resist is simultaneously applied to predetermined locations of one conductor network of the printed circuit board and all of the through holes. At the same time, a plating resist is selectively printed on predetermined portions of the conductor circuit on the other side of the printed circuit board and all of the through holes, and after the plating resist is cured, the first plating is applied. a second plating process step of depositing a second metal plating layer in a second plating solution different from the solution;
Above 1st. A method for manufacturing a printed wiring board, characterized in that a second plating process deposits different gold plating layers on different parts of the printed circuit board.