JPS62193197A - Manufacture of through-hole 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 [Object of the Invention] (Industrial Application Field) The present invention relates to a method of manufacturing a printed wiring board having through balls.

(Conventional technology) In recent years, with the demand for higher density wiring and higher mounting of components,
There is an increasing demand for through-hole printed wiring boards in which conductor patterns are formed on both sides of a substrate and are electrically connected through through-holes.

The following methods are conventionally known as methods for forming through holes in the production of through-hole printed wiring boards.

■ A method in which holes are drilled in a copper-clad laminate for both double-sided connections and mounting component insertion, and the entire surface, including the inner wall of the hole, is chemically copper plated and then electrolytically copper plated.

■ A method in which holes are similarly drilled in a copper-clad laminate and then conductive paste is filled into the holes.

However, in the method (2) of completing the through holes by copper plating, lands are always formed around the holes on both the front and back sides, which has the disadvantage of hindering the design of high-density conductor patterns. In addition, the method (2) of connecting both surfaces by filling the holes with conductive paste was not necessarily satisfactory in terms of connection reliability.

(Problems to be solved by the invention) Among the conventional through hole forming methods as described above,
The method using copper plating has the problem that lands are formed in unnecessary places, which interferes with high-density wiring.
The method (2) of filling holes with conductive paste has a problem in that the reliability of the connection is not sufficient.

The present invention was made to solve these problems, and an object of the present invention is to provide a method for manufacturing a through-hole printed wiring board with high connection reliability on both sides and in which conductor patterns are densely wired.

[Structure of the Invention] Means for Solving the Problems> The method for manufacturing a through-hole printed wiring board of the present invention includes a through-hole printed wiring board in which conductor patterns are formed on both the front and back sides, and through-holes for connection on both sides and through-balls for inserting mounted components are formed. In manufacturing the printed wiring board, first, holes for double-sided connections are drilled at predetermined positions in the copper-clad laminate, and conductive paste is filled into the holes for connecting both sides, and then holes for insertion of mounted components are formed. The feature is that the entire conductor is plated with copper, and then unnecessary portions are dissolved and removed by etching to form a conductor pattern.

(Function) In the present invention, among the two types of through holes with different capacities, a through hole for double-sided connection that does not require a land around the hole is formed by filling it with conductive paste, and then Since the through-holes for inserting the mounted components are completed by mating, connection reliability on both sides is ensured, and the density of the conductor pattern can be increased.

(Example) Embodiments of the present invention will be described below based on the drawings.

When implementing the present invention, first, as shown in FIG. After drilling the holes 4, conductive paste 5 is filled into the holes using a squeegee or high-pressure spray, and the surface is polished smooth.

Next, as shown in FIG. 1(b), holes 6 for inserting mounted components are drilled at predetermined positions in the copper-clad laminate 3, and then chemical copper plating and electrolytic copper plating are performed in order to form holes 6 for inserting mounted components. 1
A copper plating layer 7 is formed on the entire surface including the inner wall surface of 6.

After that, an etching resist is applied using a photographic method or a screen printing method, and unnecessary portions of the copper foil 2 and the copper plating layer 7 are dissolved and removed by etching as shown in FIG. form each.

In this way, the conductive paste 5 is filled in the double-sided connection hole 4, which does not require a land 8, and the copper plating layer 7 is provided in the mounting component insertion hole 6, thereby ensuring conduction on both sides of the through-hole printed wiring. A board is obtained.

[Effects of the Invention] As is clear from the above explanation, according to the method of the present invention, through holes for double-sided connection can be formed without forming lands, which increases the wiring density of conductor patterns in terms of design. be able to.

Furthermore, since both sides of the through-hole for inserting mounted components are electrically connected by copper plating layers, the reliability of the connection of the entire board is also high.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a board for explaining the present invention in detail, Fig. 1(a) shows a state in which through-holes for double-sided connection are formed, and Fig. 1(b) shows a through-hole for inserting mounted components. FIG. 1C shows a state in which conductor patterns are formed, and FIG. 1C shows a state in which a conductor pattern is formed.

Claims (1)

[Claims] (1) When manufacturing a printed wiring board that has conductor patterns formed on both the front and back sides and has through-holes for both-side connections and through-holes for inserting mounted components, first, holes for both-side connections are formed at predetermined positions on the copper-clad laminate. A conductive paste is filled in the holes for connecting the double-sided connection, then a hole is made for inserting the mounted components, and then copper plating is applied to the entire surface. After that, unnecessary parts are dissolved and removed by etching to form a conductive pattern. A method for manufacturing a through-hole printed wiring board, characterized by forming a through-hole printed wiring board.