JPS62114250A - Manufacture of printed circuit board - Google Patents

Abstract

PURPOSE:To eliminate the damage of a semiconductor chip through plated leads due to static electricity charged on an operator by cutting by etching a portion crossing the profile finishing line of plated leads exposed by removing a protecting material, and then cutting it along the profile finishing line. CONSTITUTION:Before coating a solder resist 3, a portion 4a crossing the profile finishing line L of plated leads 4 is covered with a protecting material 5, coated with the resist 3, the exposed portion of the portion 4a crossing the line L of the leads 4 is cut by etching by removing the material 5, and then cut along the line L. That is, since the portion 4 crossing the line L of the leads 4 is mechanically removed before finishing the profile, the ends of the leads 3 are not exposed on the end face of the obtained printed circuit board 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method of manufacturing a printed wiring board for a semiconductor chip carrier such as a bin grid array (PG^) or a leadless chip carrier (LCC) 9.

[Background technology 1 Conventionally, semiconductor chips have been mounted using through-hole plated printed wiring boards as chip carriers, but plated leads for through-hole plating are formed continuously with the through-holes on the end face of the printed wiring board. The cut surface of the wire is exposed, and there is a problem in that when handling the wire, static electricity charged on the handler may conduct electricity through the exposed plated lead wire to the semiconductor chip, causing it to be destroyed.

[Objective of the Invention 1 The present invention has been made in view of the above circumstances, and its purpose is to prevent the plating lead wires from being exposed on the end face of the product and to prevent the mounted semiconductor chip from being exposed to the handler's a
We manufacture printed wiring boards that cannot be destroyed by electricity.

[Disclosure 1 of the Invention The method for manufacturing a printed wiring board of the present invention is a method for manufacturing a through-hole plated printed wiring board 2 from a metal foil-clad laminate 1, in which the plating leads are removed before applying the solder resist 3. Line, part 4a that intersects with the external finishing line of 8
After covering with a protective material 5 and applying a Tsurugu resist 3, the protective material 5 is removed and the exposed portion, which is the portion 4a that intersects with the outer finish line of the plated lead wire 4, is cut by etching. This feature is characterized in that cutting is performed along the rear contour finishing line, and with this configuration, the above object can be achieved. That is, prior to external finishing, the portion 4 that intersects with the external finishing line of plating lead #iI4
Since 811 a is mechanically removed, the ends of the plated lead wires 3 are not exposed on the end face of the obtained printed wiring board 2.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In the present invention, a well-known process is adopted to manufacture the through-hole plated printed wiring board 2 from the metal foil-clad laminate 16.6For example, in the subtractive method, a copper-clad laminate is sequentially drilled and activated. Processing, electroless plating, screen printing or exposure/development (plating resist), electrolytic copper plating, electrolytic solder plating (etching resist), plating resist peeling, etching, fusing, turgorlenost printing, external finishing, symbol mark printing Through these steps, the through-hole plated printed wiring board 2 is manufactured. The gold foil-clad laminate 1 is made by arranging a resin-impregnated base material and metal foil on a resin substrate, and placing a plurality of these as a set between hot platens via a molding plate, and heating at, for example, 250°C.
The above is obtained by heating and pressing 20-150 kg/em2.40-100 minutes to integrate the M layer. Instead of a resin substrate, a 1m wood substrate in which only the actual chip VCFM portion is made of metal may be used.

In the present invention, among the conventionally well-known steps, before applying the turret resist 3, a plating lead #it that is continuous with the through-hole land formed at the same time as the circuit pattern is formed.
A portion 4a that intersects with the external finishing line 4 is covered with a protective material 5 (FIG. 1). As this protective material 5, it is possible to use tape, plating, etc. After this,
Apply a strong resist 3 (Fig. 2), then remove the protective material 5 to expose the portion 4a that intersects with the external finish ff1L of the plated lead wire 4, and cut this portion by etching (Fig. 3). Thereafter, it is pressed and cut along the outer finishing line to obtain a through-hole plated printed wiring board 2 (FIG. 4). Note that a solder resist may be applied to the exposed portion 12 after the protected forest 5 has been removed and etched. A semiconductor chip carrier A is formed by providing a recess 7 for mounting a semiconductor chip 6 on the surface of this printed wiring board 2 by mechanical cutting such as milling.

The semiconductor chip carrier A formed in this way has
As shown in FIG. 5, a semiconductor chip 6 is mounted by bonding a die 8 in a mounting recess 7, electrically connected to a circuit pattern 10 by bonding wires 9, and resin-sealed with a sealing resin such as epoxy resin. Through hole 1
1 can be used as a pin grid array by holding terminal bins, and can be used as a leadless chip carrier by allowing the through holes 11 to function as connection holes. Further, if necessary, the semiconductor chip carrier A is hermetically sealed with covers 1 and 2 made of ceramic or the like for practical use.

The present invention is a method for manufacturing a through-hole plated printed wiring board from a metal foil-clad laminate, in which the portions of the plated lead wires that intersect with the external finishing line are covered with a protective material before applying the turret resist, After applying the Tsurugo resist, the protective material is removed and the exposed plated lead wire is cut by etching at the part that intersects with the external finishing line, and then cutting is performed along the external finishing line, so the external finishing is easy. The ends of the plated lead wires are not exposed on the end face of the printed wiring board obtained by this process, and therefore, even when semiconductor chips are mounted, static electricity charged on the handler is transferred from the plated lead wires to the semiconductor chips. There is no possibility that the chip will be destroyed by being energized.

[Brief explanation of drawings]

Figures 1(a) (+1), 2(a)(b) and 3(,)(b) respectively illustrate the steps of an embodiment of the present invention; FIGS. 4(a) and 4(b) are a sectional view and a plan view showing the tentative print layout #a obtained as above, and FIG.
The figure is a cross-sectional view showing the same chip carrier, where A1 is the semiconductor chip carrier, L is the external finish 1 delineation, 11 is the metal foil clad laminate, 2 is the printed wiring board, 31 is the solid resist, and 4 is the plating. The lead wire 4al intersects with the external finishing line, and 5 is a protective material. Agent Patent Attorney Ishi 1) Long 7ml Diagram

Claims (1)

[Claims] (1) A method of manufacturing a through-hole plated printed wiring board from a metal foil-clad laminate, in which the portions of the plated lead wires that intersect with the external finish line are covered with a protective material before applying the solder resist, and the solder resist is Printing characterized by applying a resist, removing the protective material and cutting the exposed plated lead wire at the part that intersects with the finished outer line by etching, and then cutting along the finished outer line. Method of manufacturing wiring boards.