JPS59163890A - Method of partially plating board wiring - 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 Field of the Invention The present invention relates to a method for forming a local plating layer on wiring formed on a substrate by electrolytic plating, that is, a method for partial plating on wiring on a substrate.

Conventional structure and its problems A method of providing a wiring layer on an insulated substrate and selectively forming a plating layer on a part of this wiring layer has traditionally been applied to the connection terminal part to the connector or the through-hole hole wall. It is widely used in the process of forming plating layers on parts.

As for the plating method, electrolytic plating is often used because of its good stability from the viewpoint of manufacturing control.

The challenges when forming a partial plating layer on wiring on a substrate using electrolytic plating are the selective formation mask and electrode connection technology to the wiring. In other words, part of the wiring on the board is exposed,
In order to cover the other parts with a suitable coating material and to make only a part of the coating come into contact with the electrolytic plating bath, it is essential that the coating material be adhered reliably and stably and that the process of attaching and removing it be simple. On the other hand, since the wiring layers are usually separated from each other on the substrate, a reliable electrical connection to each wiring and a simple connection method are required.

OBJECTS OF THE INVENTION The present invention provides a partial plating method for substrate wiring that can solve all of the problems in the electrolytic plating method described above, is simple, and has three bases of durability.

12. In summary, a part of the wiring on the board is exposed, the other part is covered with conductive rubber, and the exposed surface part of the conductive +1 rubber is covered with a flexible insulating layer. This is a partial plating method for board wiring, which includes a step of covering a part of the wiring with an electrolytic plating layer. Easy to implement.

DESCRIPTION OF THE EMBODIMENTS FIG. 1 is a plan view of the main parts of the board wiring used in the embodiments of the present invention.
On this resin insulating layer, a wiring layer 2 made of copper foil with a thickness of about 3571 m and processed into a predetermined pattern is provided. In detail, the method of exposing the region 6 where the wide end portions 3 and 4 of each wiring layer are concentrated and forming a partial plating layer only on the wide end portions 3 and 4 is shown in Fig. 2. The system is shown in a cross-sectional diagram.The surface of the -γτ (i-region 6) of the substrate 1 is exposed, and the conductive gongs and sheet 6 are properly attached to the other surface. juxtaposed with the opposing anode 8 in the plating solution 7.The conductive rubber sheath 1-6
if: An opening 9 is formed in a portion of the substrate 1 that is located in a portion 5 of the substrate 1.
The opening wall surface and the entire surface facing the counter electrode 8 are covered with a flexible insulating layer 10. Therefore, when an electrolytic plating process is performed using the conductive rubber sheet 6 as a cathode, a plating layer 11 is formed on the exposed portion of the wiring layer. Note that the container 12 in the system is a plating bath.

Generally speaking regarding the electrolytic plating process, the plating layer metals include precious metals such as gold, silver, rhodium, and platinum, nickel,
Zinc, tin, or a tin-lead alloy is used, and the plating bath is a cyanide-based or sulfuric acid-based solution of the metal, and the conditions are: 70°C or less, and a current density of 2 to 10 A/d771.
'', generally a good plating layer can be obtained. The thickness of the plating layer varies depending on the application, but it is for adhesion of semiconductor substrates or connector terminals, and gold: 0.25 to 2.6 μm.
m.

Silver: 2.5 to 5 μm, nickel: 3 to 1011 m is suitable for 5 b-2.

As the conductive gonograph and sheet 6, for example, a commercially available product having a thickness of 5 recesses can be used.Generally, silicone rubber is mixed with metal powder and metal fibers to give an electrical resistance of 10Ω/[1 to 0 ．．
1Ω/Mold the product into any shape you like and use it. Furthermore, for the flexible insulating layer 10 covering the surface of the conductive rubber, an epoxy resin containing an aromatic amine curing agent can be used. For this resin system, for example, the amount of curing agent added to the resin base resin is ts is Phr.
(However, phr-100/200・amine equivalent) is 150°C.

Adhesion and flexibility with the conductive rubber sheet 6 are suitable under curing conditions of 30 minutes, and there is sufficient liquid resistance against plating solution. In addition, as an example of liquid resistance, durability for 1000 hours or more was observed in a cyanide gold (or silver) plating bath having a pH of 12 to 13.70°C.

Furthermore, as the coating resin, polyvinyl chloride type, ultraviolet radiation curing acrylic resin, aliphatic amine curing agent type epoxy resin, acid anhydride curing agent type melamine resin, acid anhydride curing agent type epoxy resin, etc.! 1-1'' may be used under constant conditions.

Figure 3 shows a conductive goto sheet 6 in the plating bath system.
2 is a sectional view of a resin hard plate 13 fastened to a substrate 1 with bolts 14 and nuts 15 of a holder so that the resin hard plate 13 has good adhesion to the wiring layer 2. FIG. The contact resistance of the conductive rubber sheet 6 is reduced by 1/2 to 1/100 on the order of 1/2 to 1/100 by such tightening and crimping, and the contact properties are significantly improved. This made it easier to manage the conditions for forming the plating layer, and the quality improved.

Effects of the Invention According to the present invention, by pressing conductive rubber onto the wiring layer, it is possible to form a plating layer locally on the wiring layer.
Manufacturability has been significantly improved. The method of the present invention is excellent in industrial efficiency in terms of simplicity and durability, and is highly practical.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the main parts of the board wiring used in the embodiment of the present invention,
FIG. 2 is a sectional view of the plating bath system of an embodiment of the present invention, and FIG. 3 is a sectional view of the plating bath system of another embodiment. ...Wiring layer, 3, 4...
. . . Wiring layer wide end portion, 6 . . . Exposed surface area,
6... Conductive rubber sheet, Finish... Plating solution, 8... Anode, 9... Opening, 10.
... Flexible insulating layer, 11 ... Plating layer, 12
・・・・・・Plated bathtub. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (3)

[Claims] (1) Part of the wiring on the board is exposed and the other part is conductive ('
A substrate wiring comprising a step of crimping and covering the wiring with rubber, covering the exposed surface of the rubber with a flexible insulating layer, and covering a part of the wiring with an electrolytic plating layer. partial plating method to. (2) The partial plating method for substrate wiring according to claim 1, in which the flexible insulating layer is made of an epoxy resin containing an aromatic amine curing agent. (3) The partial plating method for substrate wiring according to claim 1, in which silicone rubber is used as the conductive rubber.