JPS61276396A - Manufacture of printed wiring board - Google Patents

Abstract

(57) [Abstract] 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 is directed to a printed wiring board in which, when a waste board is separated from a main body through a cut such as a perforation, the plating layer that adheres to the cut does not remain on the main body. In particular, the present invention relates to a method for manufacturing a composite double-sided through-hole substrate.

"Conventional technology" In general, holes are provided in the printed wiring board for positioning, not only when manufacturing printed wiring boards, but also when mounting electronic components on the printed wiring boards after manufacturing using automatic machines. There is. The part with the positioning hole will eventually become unnecessary.

Then, it is separated from the main body through a cut such as a perforation and thrown away. However, after forming the notches in the printed wiring board, especially a composite double-sided through-hole board, if the through-holes are plated with spores, the plating layer will also adhere to the notches, and the portions with the positioning holes, so-called waste. When the board t and other parts are separated from the main body, a plating layer remains attached to the separated end face of the main body, and this remaining plating layer reduces the insulation of the printed wiring board itself and may cause other undesirable situations. Expected to occur.

Therefore, conventionally, a manufacturing method has been adopted in which a plating layer is not provided at the cut portion at the time when the waste board is separated from the main body at the cut portion. The manufacturing method involves plating the through holes, etc., and then performing secondary processing to form cuts such as perforations.
The number of man-hours increased, leading to higher costs. In addition, a tending method using dry film was also adopted.

In this method, holes including the above-mentioned cuts are drilled on a board with copper foil laminated on both sides, and then electroless plating or electrolytic plating is applied. In this plating process, a plating layer is formed not only in the through holes but also in the notches. Thereafter, a positive dry film is baked to form a wiring pattern, and after an etching process is performed to remove the copper foil other than the wiring pattern, the dry film is removed. The plated layer once formed at the cut portion is removed by the etching process. However, although this method does not have a plating layer on the cut portion when the waste board is separated from the main body, it has the problem that the method is complicated and expensive compared to the widely used printing method. Ta.

``Problems to be Solved by the Invention'' In view of the above circumstances, the present invention utilizes the generally widely used printing method as is for printed wiring boards in which through-holes are plated, but does not require an increase in the number of steps. (An object of the present invention is to provide a method for manufacturing a printed wiring board that can prevent the plating layer from remaining in the cut portion on the main body side when cutting the waste board from the main body.

``Means for Solving the Problems of the Invention'' In order to achieve the above-mentioned object, the present invention provides a method for manufacturing a copper-clad laminate in which predetermined wiring patterns and through holes are formed in a copper-clad laminate. When forming a wiring pattern on a board by etching, copper foil is placed on the part that should be a waste board close to the main body, and cuts such as perforations are formed at the boundary between the waste board and the main body. The method of manufacturing a printed wiring board is characterized in that the wiring pattern is then plated.

``Example'' An example of the method for manufacturing a printed distribution board according to the present invention will be described below with reference to the drawings. FIG. 1 shows, using a well-known method,
A copper-clad laminate 2 with copper clad on both sides of a substrate 10 made of synthetic resin, so-called resin, is drilled to form through-holes, etc., and each copper-clad surface is etched to form a predetermined wiring pattern. 3't', · is formed. in this case,
Normally, the holes are etched after processing, but when the holes are processed, the main body 2 on which the wiring pattern 3 is formed.
At the same time, one perforation 4 is made as a cut portion at the boundary between a and a portion to become the scrap board 2b. The waste board 2b is provided with holes 5 for positioning during the manufacturing process of the printed wiring board and for positioning when electronic components are subsequently mounted on the printed wiring board using an automatic machine. The hole 5 may be formed at the same time as the processing, or may be formed in advance before the start of manufacturing. Contrary to the above, it is also possible to perform etching to form a predetermined wiring pattern 3' and then to form the holes.

In the present invention, when forming a predetermined wiring pattern 3 by etching each of the copper-clad surfaces, the groove shown in FIG. 1 and FIG. A copper foil 6 having a predetermined width and corresponding to the length of the separated end, for example, slightly longer than the length at which the perforations 4 are formed, is left (.

It is preferable to form this copper foil 6 on both sides, but it is also possible to form it only on one side.

Next, as shown in FIGS. 2 and 5, a copper plating layer 7y is applied to the entire area of the wiring pattern 3 by electroplating or electroless plating. #Form. This copper plating layer 7 is formed not only in the through hole 8 shown in FIG. 2 but also in the perforation 4. Furthermore, as shown in FIGS. 3 and 6,
Solder plating is applied except for 30 predetermined locations on the wiring pattern that will become plug-in terminals. As a result, the solder plating layer 9 is formed not only in the through skewer 8 but also in the hole of the perforation 4.

Next, when electronic components are mounted on the main body 2a of the printed wiring board using an automatic machine, the positioning holes 5 are no longer necessary and the waste board 2b is no longer necessary.

Separate the waste plate 2b from the main body 2a at the perforation 4. In this separation, as shown in FIGS. 3 and 6, all of the copper plating layer 7 and the solder plating layer 9 formed in the hole of the perforation 4 adhere to the separated end surface of the waste board 2b, and the main body 2a
It does not remain on the cut end face. In other words, the bonding force between the copper tiles is stronger than the adhesion between the resin, which is the material of the substrate 1, and the hook, so the copper plating layer 7 adheres to the hole of the perforation 4.
And the solder plating layer 9 is integrally combined with the copper foil 6 formed on the separated end of the waste board 2b, and when the waste board 2bt' is separated from the main body 2a, all of the copper plating layer 7 and the solder plating layer 9 are It adheres to the separated end face of the waste plate 2b and does not remain on the separated end face of the main body 2a.

Note that the solder plating process described above can not only be performed selectively on the wiring pattern 3, but also can be applied to the entire area of the wiring pattern 3. Furthermore, the present invention can be applied as is to the case where the electrolytic or electroless copper plating process is performed and no solder plating process is performed. Further, the cut portion is not limited to the above-mentioned perforation 4, and it goes without saying that it may be of the form of a slit in which only the two ends of the cut or separation portion are slightly connected.

"Effects of the Invention" As described above, according to the method for manufacturing a pre-wiring board according to the present invention, after forming cuts such as perforations so that the waste board can be separated from the main body on which the wiring pattern is formed, Even if a plating layer is formed in the cut area during plating,
The plating layer at the notch is integrally bonded to the copper foil formed on the scrap board, so when the scrap board is separated from the main body at the notch,
All of the plating layer at the cut portion adheres to the waste board and does not remain on the cut-off end surface of the main body. As a result, the plating layer does not remain on the cut-off end surface of the main body, causing problems such as poor insulation. , and can use commonly used printing methods.
Moreover, since there is no increase in the number of steps, it can be carried out at low cost.

[Brief explanation of the drawing]

The drawings show an embodiment of the method for manufacturing a printed wiring board according to the present invention, the first and second factors are plan views of main parts showing the manufacturing process of the printed wiring board, and the third factor is a diagram from the main body of the printed wiring board. Figures 4 and 5 are enlarged cross-sectional views of the main parts showing the manufacturing process of the printed wiring board, and Figure 6 is the scrap board separated from the main body of the printed wiring board. FIG. 3 is an enlarged sectional view of the main part in the state. 2a... Main body 2b... Waste board 3... Wiring pattern 4... Perforation 5... Positioning hole 6... Copper foil remaining on waste board 7... Copper plating 8...・Through hole 9・
...Solder plating patent applicant Michi Isono, patent attorney and agent of Tokyo Print Kogyo Co., Ltd. Figure 1 Figure 3 Figure 4 Figure 5 O Figure 6

Claims (1)

[Claims] In a method of manufacturing a printed wiring board in which a predetermined wiring pattern and through holes are formed on a copper-clad laminate, when a wiring pattern is formed on the copper-clad laminate by etching, a part that is to be a waste board is close to the main body. A method for manufacturing a printed wiring board, which comprises leaving copper foil at certain locations, forming cuts such as perforations at the boundary between the waste board and the main body, and then plating the wiring pattern.