JPS5843242Y2 - printed wiring board - Google Patents

Description

[Detailed Description of the Invention] The present invention aims to provide a high-quality printed wiring board that is free from cracks, cracks, cracks, chips, etc. during press punching.

Generally, a printed wiring board is made by forming a conductive pattern on one or both sides of an insulating substrate by etching or plating, forming a solder resist, component layout diagram, etc. as necessary on the insulating substrate, and then punching holes with a press. It is constructed with external processing.

By the way, in printed resistance wiring boards, silver through-hole wiring boards, crossover wiring boards using silver paint, etc., after forming a conductive pattern by etching, it is common to print and harden various thermosetting inks. The deterioration of the insulating substrate is significant due to prolonged heating and curing.

If press punching such as external shaping and hole drilling is performed in such a deteriorated state, cracks, cracks, and cracks will occur around the punched holes in areas with high hole density.

Chips, etc. would occur.

In particular, cracks occur when drilling holes in areas where conductive patterns are not formed and are lower than the height of the conductive pattern portion during press punching.

The occurrence of cracks, breaks, chips, etc. was significantly increased.

Figures 1 and 2 show an example of a conventional printed resistor silver through-hole wiring board, in which 1 is an insulating substrate made of a synthetic resin laminate, and a conductive pattern 2 made of copper foil is formed on the underside of this insulating substrate 1. An undercoat 3 is formed on the upper surface of the insulating substrate 1, and a through hole 4 formed in the insulating substrate 1 is filled with silver paint 5 to form a through hole, and a circuit pattern 6 made of silver paint is formed on the undercoat 3. and printed resistor 7
The upper surface of the insulating substrate 1 was covered with an overcoat 1-8, and holes 9 such as perforations for mounting and cutting were formed in the blank insulating substrate 1.

Many of the above-mentioned cracks, cracks, and chips 10 were generated around the mounting holes 9 and perforations.

The present invention eliminates the above-mentioned drawbacks of the prior art.

Embodiments of the present invention will be described below with reference to FIGS. 3 to 6.

First, in FIGS. 3 and 4, reference numeral 11 is an insulating substrate made of a laminated board of synthetic resin such as epoxy glass. A conductive pattern 12 made of copper foil is formed on the lower surface of this insulating substrate 11, and an undercoat is formed on the upper surface. 13 is printed in a pattern.

This undercoat 13 is also formed in the parts where mounting holes and perforations for cutting and separation are formed in the final manufacturing process of the printed wiring board.

Further, a through hole 14 for a through hole is formed in this insulating substrate 11, and a silver paint 15 for a through hole is formed in this through hole 14.
A circuit pattern 16 made of silver paint 15 and a printed resistor 17 are formed on the undercoat 13 on the upper surface.

This circuit pattern 16. Print resistance 17. An overcoat 18 is formed on both sides of the through-hole silver paint 15 and on the parts where mounting holes and perforations are to be formed.

Furthermore, undercoat 13. Attachment or cutting holes 19 are formed in the portions where the overcoats 1 to 18 are formed, and the entire periphery of the hole 19 is surrounded by the overcoat 18.

When the hole 19 is formed by press punching in the final process as described above, there is almost no difference in plate thickness from other parts, and the overcoat 18 is formed all around the hole 19. There were no cracks, cracks, cracks, chips, etc. in the surrounding area.

Furthermore, what is shown in FIG. 5 is an example of a silver crossover wiring board in which a circuit pattern 16 made of silver paint is crossed over a conductive pattern 12 with an insulating resin 20 interposed therebetween. This is an example in which the hole 19 is formed all around the hole.

Furthermore, in the case shown in FIG. 6, an insulating resin 21 is formed by printing or the like all around the hole 19 for mounting the insulating substrate 11 made of glass epoxy with a plate thickness of 0.1 mm, so that the thickness of the conductive pattern 12 is increased. It is configured so that it is the same as the

There were no cracks, cracks, cracks, chips, etc. around the holes 19 in any of these printed wiring boards.

Since Print 1 to the wiring board of the present invention are constructed as described above, cracks may occur around the mounting or cutting holes formed by press punching in the final manufacturing process.

There are no cracks, splits, chips, etc., and the quality is significantly improved, which is of great practical value.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the main parts of a conventional printed wiring board, FIG. 2 is a top view of the same, FIG. 3 is a top view of the main parts of an embodiment of the printed wiring board of the present invention, and FIG. The figure is the same sectional view, Figure 5,
FIG. 6 is a top view of the main parts of another embodiment. 11...Insulating substrate, 12...Conductor pattern, 13...Undercoat, 14...
・Through hole for through hole, 15・・・Silver pane l-
116...Circuit pattern, 17...Printed resistance, 18...Overcoat 1-119...
... Hole, 20.21 ... Insulating resin.

Claims (1)

[Scope of utility model registration request] In a printed wiring board consisting of an insulating substrate on which a conductive pattern is formed, and mounting or cutting holes are provided in the part where the conductive pattern is not formed, the entire circumference around the hole where the mounting or cutting hole is formed is A printed wiring board that includes an insulating resin layer that has the same thickness as the conductive pattern.