JPH0334494A - Manufacture of horizontal 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 (Industrial Application Field) The present invention relates to a method for manufacturing a horizontal printed circuit board for use in encoders and rotary switch boards.

(Prior art) One of the conventional methods for making horizontal printed circuit boards is to form circuits by etching a copper-clad laminate, and then pour liquid resin mixed with a hardening agent into the recesses between the circuits. There is a way to make a horizontal printed circuit board.

(Problem to be Solved by the Invention) By the way, in the above method for manufacturing a horizontal printed circuit board, gas bubbles generated when the liquid resin poured into the recesses between the circuits hardens, and the copper foil of the copper-clad laminate or the base material Due to the air bubbles adhering to the top, air bubbles remained in the resin filled in the recess. Furthermore, the thickness of the resin was uneven, and the amount of polishing required during polishing was uneven, making it difficult to polish.

SUMMARY OF THE INVENTION Therefore, the present invention provides a method for manufacturing a horizontal printed circuit board that does not generate bubbles in the resin filled in the recesses between the circuits and can have a uniform thickness.

(Means for Solving the Problems) A method for manufacturing a horizontal printed circuit board of the present invention to solve the above problems involves etching a copper-clad laminate to form a circuit, and then placing a prepreg on the circuit surface. The recesses between the circuits are filled with resin by crimping with a vacuum hot press, and then the resin on the circuits is polished to make the circuit surface and the resin surface on the same plane.
The feature is that the surface is then plated with nickel and gold.

(Function) As described above, in the method for manufacturing a horizontal printed circuit board of the present invention, a prepreg is placed on the surface of a circuit formed by etching a copper-clad laminate, and is crimped with a vacuum hot press to apply resin to the recesses between the circuits. Since the prepreg is filled, no gas is generated in the prepreg, and air bubbles that have adhered to the copper foil or base material of the copper-clad laminate are removed. Therefore, no bubbles are generated in the resin.

Furthermore, since the resin on the circuit is polished to make the circuit surface and the resin surface on the same plane, the resin filled in the recesses between the circuits can have a uniform thickness.

(Embodiment) An embodiment of the method for manufacturing a horizontal printed circuit board of the present invention will be explained with reference to the drawings. First, as shown in FIG.
mm, thickness 105 μm on the surface of base material 1 with width 250 mm
The copper clad laminate 3 to which the copper foil 2 was bonded was etched to form a circuit 4 as shown in FIG. Next, add the third circuit on circuit 4.
As shown in the figure, the thickness is 100 μm, 330 mm vertically, 250 mm horizontally.
A plurality of sheets of prepreg 5, in this case three sheets, are stacked and pressed in a vacuum hot press (not shown) at a pressure of 20 kg/m.
c++f, curing temperature 180℃, time 70 minutes, vacuum degree 1~
They were crimped under conditions of 20 mm and 1 g, and the recesses 6 between the circuits 4 were filled with resin 7 as shown in FIG.

Next, the resin 7' on the circuit 4 was polished to make the surface of the circuit 4 and the surface of the resin 7 in the recess 6 between the circuits 4 flush with each other, as shown in FIG. Thereafter, as shown in FIG. 6, a nickel-gold 99.5% plating 8 was applied to 3.0 μm to obtain a horizontal printed circuit board 9.

When the resin 7 portion of the horizontal printed circuit board 9 thus obtained was observed using a stereoscopic microscope (XIO), no bubbles were observed.

In addition, before applying 99.5% nickel-gold plating 8,
When the smoothness was measured using a surface roughness meter, the smoothness was extremely high at 1 μm or less.

In the manufacturing method of the present invention, an appropriate number of prepregs with an appropriate thickness are used depending on the thickness of the copper foil, which are placed on the circuit surface and bonded using a vacuum hot press.

(Effects of the Invention) As can be seen from the above explanation, according to the method for manufacturing a horizontal printed circuit board of the present invention, there is no generation of air bubbles in the resin filled in the recesses between the circuits, and the thickness of the resin is uniform. There is an effect that a printed circuit board can be obtained.

[Brief explanation of drawings]

1 to 6 are diagrams showing the steps of the method for manufacturing a horizontal printed circuit board according to the present invention.

Claims (1)

[Claims] 1. Form a circuit by etching the copper-clad laminate, then place a prepreg on the circuit surface and press it with a vacuum hot press to fill the recesses between the circuits with resin, then polish the resin on the circuit. A method for manufacturing a horizontal printed circuit board, characterized in that the circuit surface and the resin surface are made on the same plane, and then nickel-gold plating is applied to the surface.