JPS63228799A - Manufacture of printed wiring 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] With the development of heat-resistant substrate materials, it has become increasingly necessary to directly mount and bond semiconductor chips onto printed wiring boards, or to plate the inside of the board with precious metals as switching and connection terminals. ing. Electrolytic noble metal plating is applied to the inside of the printed wiring board other than the peripheral edges, as the density of the circuit increases, making it difficult to draw plating conductive lines to each independent terminal inside the board.

For this reason, until now, plated conductive wires have been collected in one place and cut by counterboring, pressing, or drilling.

This method requires a space to collect the plated conductive wires in one place, and the machining process for this purpose often scratches or stains the plated surface, and there is a risk that the cut conductive wires may short-circuit. There is sex.

The present invention solves these problems by using a conductive jig as a part of the plating master, thereby making it possible to conduct the plating mask and conduct electricity at the same time.

Although the present invention is mainly effective for plating bonding points, it is also effective in cases where it is difficult to route plating continuity at other switching or connection contacts.

A method of plating the terminal terminals of the board using an elastic connector, etc. has also been devised, but this is only for energizing a part of the terminal terminal, and in the present invention, electroless nickel is used as the base before the mask. By using electroless precious metal plating to cover areas other than electroplating, it prevents rust on other exposed patterns on the board, improves solderability, and prevents copper from entering the electrolyte during electrolytic plating. This prevents the elution of

It is of course possible to cover unnecessary parts with solder resist or the like for both electrolytic and electroless plating.

It is also possible to consider a board that does not require noble metal plating except for the terminals, but in that case, anti-rust treatment such as flux treatment is required.

As described above, the present invention is an epoch-making manufacturing method that enables inexpensive noble metal plating to be applied thickly to terminals inside a board where it is impossible to route plated conductive wires.

It should be noted that electrolytic plating is used for thickening (0
, 1μ or more) is difficult to plate, and even if it can be thickened, the hardness and bonding properties are inferior to electrolytic plating. The reason why it is used as a plating mask is to reduce the area to which precious metal plating is attached and to lower costs.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a patterned copper-clad laminate; Figure 2 is a substrate coated with electroless nickel and plated with a noble metal; Figure 3 is a cross-sectional view of a substrate plated with a thick layer of precious metal using a plating mask. 1. Insulating layer 2. Copper foil 3. Electroless nickel 4
．． Electroless precious metal plating 5. Electrolytic precious metal plating 6.
Conductive rubber 7. Insulating rubber 8, Supporter - Cleaning of drawings (no change in content) Y21] Procedural amendment June 24, 1988 Patent application No. 063613 2, Title of invention Method for manufacturing printed wiring board 3, Amendment 4. Agent: None 5. Date of amendment order (shipping date) May 26, 1988 6. Subject of amendment Drawing 7. Contents of amendment

Claims (1)

[Claims] Through holes (on one side, both sides, through holes (
(including multilayer), etc. After that, electroless nickel plating is applied to the exposed entire surface of the pattern, and electroless precious metal plating is applied thereon. After that, apply conductive rubber around the areas where thick precious metal plating is required.
Masks using conductive materials such as elastic connectors,
Cover unnecessary parts of thick precious metal plating and turn on electricity at the same time.
A method of manufacturing a printed wiring board, characterized by applying electrolytic plating of precious metals partially to circuits that do not have plated conductive lines.