JPH0360091A - Push-back method - Google Patents

Abstract

PURPOSE:To prevent warpage, distortion of a printed board in a push-back process by opening predetermined holes along the periphery of the board of an original plate. CONSTITUTION:After a wiring pattern is formed on an original plate 1, long holes 4 are opened along the punched lines on the periphery of the board. Peripheral parts 5 having small rigidity are formed on the periphery of the board by opening the holes 4. When the boards 2 are punched and further engaged back, forming distortions generated in case of pouching and repelling between the plate 1 and the boards 2 in case of engaging back are released by deforming the peripheral parts 5 to prevent the warpages, distortions of the boards 2, the plate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a pushback method for simultaneously holding a plurality of printed circuit boards when components are mounted on a wiring printed circuit board.

[Conventional technology]

When mounting components on printed circuit boards for wiring, there is a push bank method as a method for holding multiple printed circuit boards at the same time.

The method will be briefly described in FIGS. 2 and 3 (A) and (B).

A wiring pattern is formed in advance on a base plate 1 from which a plurality of printed circuit boards 2 (four in the figure) can be punched, and holes for mounting parts are drilled, and then the printed circuit boards 2 are punched out using a die 3 ( In FIG. 3(A)), the punched substrate 2 is forcibly fitted back into the punched hole.

Thus, the original board 1 is in a state in which a plurality of printed circuit boards 2 are held, and the plurality of circuit boards 2 can be integrally processed during component mounting such as insertion of components and soldering.

A problem with such a pushback method is that when the substrate 2 is forcibly fitted back onto the original plate 1, the resistance between the substrate 2 and the original plate 1 causes warping and distortion in the entire original plate 1 and substrate 2.

Conventionally, the method for removing warps and distortions has been to apply pressure and heat using a hot press to correct warps and distortions.

[Problems to be Solved by the Invention] However, in the conventional straightening method described above, only the apparent warping and distortion are removed, but residual stress that causes the warping and distortion remains in the substrate. .

For this reason, if the board is heated during soldering in the soldering process after component mounting or during solder remelting in a furnace, the residual stress will be released and the board will warp or distort again. The occurrence of warpage and distortion causes damage to parts and poor soldering of parts, leading to lower yields and lower product reliability.

In view of these circumstances, the present invention aims to prevent the occurrence of warpage and distortion of the substrate in the pushback construction method.

[Means for Solving the Problems] The present invention provides a push-back method in which a plurality of printed circuit boards for wiring are punched out from an original board, and further fitted back to hold the plurality of printed circuit boards for wiring. The feature is that required holes are bored along the periphery of the part.

[Operation]By drilling the required holes along the periphery of the printed circuit board, the rigidity of the periphery of the printed circuit board is reduced,
The peripheral portion absorbs the distortion that occurs when the printed circuit board is punched out and refitted, thereby preventing warping and distortion in the original board and printed circuit board.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

After forming a wiring pattern on the original board 1, long holes 4 are bored around the board portion along each punch line.

By forming the elongated hole 4, a peripheral portion 5 having low rigidity is formed around the substrate portion.

Therefore, when the substrate 2 is punched out and further fitted back, the processing strain caused during punching and the warp between the original plate 1 and the substrate 2 when fitted back are released by the deformation of the peripheral portion 5. , substrate 2
, warpage and distortion of the original plate 1 are prevented.

In addition, in the above embodiment, long holes were bored along the punching line, but
A plurality of round holes may be bored along the punch line.

[Effects of the Invention] As described above, according to the present invention, it is possible to prevent warpage and distortion of the original plate and board in the pushback method, prevent damage to mounted components, improve mounting accuracy, and improve soldering. This will greatly contribute to improving yield and product quality.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of an example of a plant of the present invention, Figures 2 and 3 (
A>(B) is an explanatory diagram of a conventional example. 1 is an original plate, 2 is a substrate, 3 is a mold, 4 is a long hole, and 5 is a peripheral portion. Patent application Hito Kokusai Electric Co., Ltd.

Claims (1)

[Claims] 1) In the pushback method, in which a plurality of wiring printed circuit boards are punched out from an original board, and then fitted back together to hold the plurality of wiring printed circuit boards, required holes are punched along the periphery of the printed circuit board portion of the original board. The pushback method is characterized by