JPH10126024A - Wiring board having end-face through hole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the clogging of end-face through holes or through hole lands and peeling of a plated copper layer by making the parts of the through holes which come into contact with the cutting tooth form of a die to non- through parts after the plated copper layer is formed and the through holes are formed in cutting the through holes at their centers. SOLUTION: Through holes 2 having circular or elliptic cross sections are formed through a double-sided copper-plated laminated board 1 with a drill or router, etc., so that the holes 2 can be arranged in a straight line in parallel or obliquely to the end face 1A of a printed wiring board near the end face 1A. After the holes 2 are formed, a plated-copper layer 4 is formed on the entire surface of the laminated board 1 including the holes 2 and the through holes 2 are changed to through holes 5 by plating the entire surface with copper. Then parts of the holes 5 at their centers, namely, the parts of the holes 5 intersecting the cutting lines 12 of the holes are formed to non-through hole parts 11 by removing the plate copper layer 4 through perforation with a drill, router, die, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board, and more particularly to a structure of an end face through-hole wiring board.

[0002]

2. Description of the Related Art A conventional method for manufacturing an end face through-hole wiring board is as follows. First, as shown in FIG. 3 (a) as a conventional example 1, a straight line is formed along the end face 1A near the end face of a double-sided copper-clad laminate 1. Drilling is performed to drill through-hole 2. Next, as shown in FIG. 3B, copper plating is applied to the entire surface of the double-sided copper-clad laminate 1 including the through-holes 2 to cover the copper plating layer 4 to form through-holes 5. Then, as shown in FIG. 3C, a predetermined pattern is formed by a screen printing method or a photographic method, and an etching process is performed to form a through-hole land 6. Thereafter, as shown in FIG. 3 (d), after applying the solder resist 7, a press working is performed in advance by using a press die at a cutting line 12 passing through a substantially central portion of the through-hole 5, and FIG. As shown in FIG. 1B), a semi-cylindrical through-hole 8 in which the through-hole land 6 is in contact with the cut end surface 13 is formed.

[0004] As a conventional example 2, as shown in FIG. 4, the steps of FIGS. 4 (a) to 4 (d) are the same as those in the manufacturing process of the conventional example 1, and are shown in cross section. In the manufacturing method of Conventional Example 2, after the steps shown in FIGS.
As shown in FIG. 4E, the inside of the through-hole 5 is filled with a resin 9 and dried and hardened. Then, as shown in FIG. The printed wiring board is cut substantially at the center of the through-hole 5 and the like. Thereafter, the resin 9 remaining in the end-face through-hole is removed by a chemical or the like, and the semi-cylindrical through-hole 8 is cut into the cut end face of the printed-wiring board 13 is formed.

[0004]

However, these conventional manufacturing methods have the following problems. (1) In the method of cutting at the substantially center of the through-hole 5 by pressing using the mold of the conventional example 1 shown in FIG. 3, the through-hole is crushed by the impact at the time of cutting, or the copper plating layer 4 of the through-hole is cut. May peel off from the inner wall, resulting in poor contact between the component lead wire and the through-hole plating joint.

(2) In the manufacturing method of the conventional example 2 shown in FIG. 4, the resin 9 is filled in the through-hole 5 and the surface of the printed wiring board is made flat by changing the fluidity, viscosity change and drying of the filler. However, there is a problem that it is difficult to control the properties, adhesion, and the like, the number of work steps is increased, and the productivity is reduced by 30 to 40%.

(3) Another problem of the manufacturing method of the conventional example 2 is that, after cutting the resin-filled through-hole and removing the filled resin with a chemical, a resin residue is formed on the inner surface of the through-hole, the through-hole land 6 and the surface. It adheres to the land with mounting surface and causes poor solder wettability, making it impossible to secure connection reliability.

An object of the present invention is to provide an end-face through-hole wiring board in which the inner wall of the semi-cylindrical through-hole 8 and the through-hole land 6 are free from hole clogging and peeling of the copper plating layer 4 and connection reliability can be ensured. To provide.

[0008]

Means for Solving the Problems The through-hole through-hole 5 of the present invention is formed by applying a copper plating to cut through the substantially central portion of the through-hole 5 by pressing using a die or the like. Thereafter, a part of the end face through hole 3 which comes into contact with the blade portion of the die is formed into a non-through hole portion 11 by a router process, a drill process, a press die process, or the like.

Further, in the step of forming through-hole lands and circuit conductors on the outer layer surface, the non-conductive portion 11A is provided so that the through-hole lands 6 on the outer layer surface of the laminate do not contact the cutting line 12, thereby reducing the die. No contact is made between the blade-shaped portion and the through-hole land 6 on the surface of the outer layer, and peeling of the through-hole land 6 and the copper plating layer 4 does not occur.

The method of cutting at the substantially central portion of the through-hole 5 is not only a press working using a die but also a method of cutting after router processing, laser processing and V-groove processing. The object can be achieved because the conductor of the hole wall surface and the outer layer surface of No. 5 does not touch.

[0011]

Next, an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a perspective view of a typical completed end face through hole of the present invention. First, a through-hole 2 is drilled at a predetermined position on a straight line along the end face 1A near the end face of the double-sided copper-clad laminate 1 or the multilayer laminate, copper plating is applied to the entire surface of the laminate, and then the through-through is performed. A substantially central portion of the hole 5 is formed as a non-through hole portion 11 by drilling, router processing, drilling with a press die, or the like. Next, a predetermined pattern is formed, and application of solder resist 7 and solder leveler, Ni are performed in view of improving solderability, reliability, and wire bonding workability.
-Au plating or the like is performed. Thereafter, when the printed wiring board is cut by die-cutting, router processing, V-groove processing, or the like on the substantially central portion of the through-hole 5 on a straight line, the cut end face 13 and the hole wall surface 5A of the through-hole 5 are cut. Since the tip 4A of the copper plating layer formed on the substrate and the through-hole land 6 on the outer layer surface are isolated by the non-through-hole portion 11 and the non-conductor portion 11A and do not contact the conductor portion, the through-hole copper plating layer 4 and the through-hole No peeling of the hole land 6 occurs.

The shape of the through hole 2 formed in the end face through hole 3 is not limited to a round hole, but may be an elliptical hole, an elliptical hole, a square hole, or a rhombus hole. The cut portion is not limited to a circular shape, and may be a square, a triangle, a diamond, a U-shape, or the like as long as the cut portion is the non-through-hole portion 11.

[0013]

An embodiment of the present invention will be described with reference to FIG. FIGS. 2A to 2F are plan views showing the order of steps for explaining the present invention. First, on a double-sided copper-clad laminate 1 as shown in FIG. 2 (a), a predetermined portion is rounded by drilling, router processing or the like so as to be arranged in a straight line parallel or oblique near the end face 1A of the printed wiring board. A through hole 2 having a hole shape or an oval shape is formed. Here, the double-sided copper-clad laminate 1 may be a multilayer laminate having an inner layer formed thereon, and is not particularly limited. Next, as shown in FIG.
Copper plating is performed on the entire surface of the double-sided copper-clad laminate 1 including the through hole 2 to form a copper plating layer 4 having a thickness of 10 μm to 30 μm.

Next, as shown in FIG. 2C, a part of the center of the through hole 5, that is, the through hole 5 is formed.
The copper plating layer 4 is formed by drilling, router processing, punching with a press die, etc.
Is removed to provide the non-through-hole portion 11. The width of the non-through hole portion 11 is 0.3 to 1.0 mm, and
And the plated layer 4 on the wall surface 5A of the through-hole.

Next, as shown in FIG. 2D, a predetermined pattern is formed at a predetermined location by a screen printing method or a photographic method, and an etching process is performed to form a circuit conductor including the through-hole land 6. . In forming this circuit conductor, the non-conductive portion 11A is spaced from the cutting line 12 by a distance of 0.1 to 0.5 mm so that the through hole land 6 on the outer layer surface of the printed wiring board and the cutting line 12 of the end surface through hole 3 do not come into contact with each other. To form a through-hole land 6 on the outer layer surface.

Next, as shown in FIG. 2E, a solder resist 7 is applied to cover a circuit conductor which does not require soldering or contact connection. Thereafter, as shown in FIG. 2 (f), a substantially central portion of the predetermined through-holes 5 arranged on a straight line near the end face is cut out by die punching, router processing, V-groove processing, or the like. The cut end face 13 and the tip 4A of the copper plating layer on the hole wall surface 5A of the through-hole and the cut end face 13 and the through-hole land 6 on the outer layer surface have a non-through hole portion 11 having a width of 0.1 to 0.5 mm. The conductor portion 11A is present, mechanical stress is avoided, and the through-hole copper plating layer 4 and the through-hole land 6 are not peeled off, and the end-face through-hole 3 with high connection reliability without the occurrence of copper foil burrs is formed. Can be.

[0017]

As an effect of the present invention, when cutting is performed at the center of predetermined through-holes 5 arranged on a straight line near the end face of the printed wiring board, the impact of the cutting operation causes the first conventional example.
In this case, the copper plating layer 4 and the through-hole land 6 may be peeled off and a contact failure may occur at the end surface through-hole portion. However, in the present invention, the cutting line 12 and the hole wall surface 5A of the through-hole 5 are formed.
Copper plating layer 4 and through-hole land 6 on the outer layer surface
A non-through-hole portion 11 and a non-conductor portion 11A exist between the through-hole copper plating layer 4 and the through-hole land 6;
There is no peeling of copper foil and no defects of copper foil burrs. Further, as in Conventional Example 2, in order to prevent the copper plating layer 4 and the through-hole land 6 from peeling off at the time of cutting at the center of the through-hole 5, the resin 9 is filled inside the through-hole 5. There is no need to apply the method, the operation is simplified, and the production efficiency is improved by 30% to 35%.

[Brief description of the drawings]

FIG. 1 is a perspective view of an end face through hole according to the present invention.

FIG. 2 is a plan view illustrating the present invention in the order of steps.

FIG. 3 is a plan view illustrating a conventional example 1 in process order.

FIG. 4 is a plan view illustrating a conventional example 2 in process order.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Double-sided copper-clad laminate 1A ... End surface 2 ... Through-hole 3 ...
End face through hole 4 ... Copper plating layer 4A ... Front end of copper plating layer 5 ... Through through hole 5A ... Through hole hole wall surface 6 ... Through hole land
7: Solder resist 8: Semi-cylindrical through-hole 9: Resin 11: Non-through-hole portion 11A: Non-conductor portion 12: Cutting line 13: Cutting end surface

Claims (2)

[Claims] 1. A cut end surface formed by cutting a substantially central portion of through-holes arranged on a straight line of a double-sided copper-clad laminate or a multilayer laminate, and a cut end surface formed on a hole wall surface of the through-hole. Characterized in that a non-through hole portion exists between the end portion of the copper plating layer and the end face through-hole wiring board. 2. A cut end face formed by cutting a substantially central portion of through-holes arranged on a straight line of a double-sided copper-clad laminate or a multilayer laminate, and a cut end face formed on an outer layer surface of the through-hole. A through hole land having a non-conductive portion between the end face through hole land and the through hole land.