JPH0227575Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a mounting structure of a printed circuit board used in small electronic devices such as timers.

[Background technology]

FIG. 1 shows a conventional printed circuit board mounting structure, in which a notch 2 is provided at the end of a first printed circuit board 1 placed horizontally in the figure, and the notch 2 is placed in a direction substantially perpendicular to this printed circuit board 1. A protrusion 4 provided at the upper end of the second printed circuit board 3 is fitted into the notch 2 from below, so that both the printed circuit boards 1 and 3 are arranged three-dimensionally. The protrusion 4 is provided with a connection pattern 6 corresponding to the connection pattern 5 of the printed circuit board 1 on one side, and this connection pattern 6 is connected to the connection pattern 5 facing the edge of the notch 2. This is to electrically connect the circuits on the printed circuit board 1 and the circuits on the printed circuit board 3.

By the way, in this state, printed circuit boards 1 and 3
In the mounting structure of printed circuit boards that are soldered together, when replacing some of the electronic components on printed circuit boards 1 and 3 for repair etc., or when replacing part of the entire printed circuit board, it is necessary to connect the printed circuit boards due to the structure. It is necessary to separate the printed circuit boards by removing the soldering, but in the conventional example in which soldering is performed with the connection patterns 6 and 5 joined together as described above, the connection patterns 5 and 6 are connected to the edge of the board. Once soldered, the solder is not completely removed due to capillary action, and if the printed circuit board is separated without this solder being removed, the connection pattern 5 will be removed. , 6 causes the copper foil of the connection patterns 5, 6 to peel off from the substrate, resulting in a loss of reliability and the disadvantage that it cannot be reused. In addition, in the conventional example, as described above, it is not easy to remove the solder, so when removing the solder, too much heat is applied to the pattern, and the connection patterns 5 and 6 tend to peel off.

In the case of conventional examples like this, due to damage caused by pattern peeling, the number of reuses depends on the pattern area, but in the case of paper phenol-based printed circuit boards, it is generally 1 to 1.
The limit was two times.

[Purpose of invention]

This invention was created in view of the above-mentioned drawbacks.
The purpose of this is to create a gap between connection patterns for soldering between printed circuit boards that does not impair mechanical soldering strength in a printed circuit board mounting structure in which multiple printed circuit boards are assembled three-dimensionally. Accordingly, it is an object of the present invention to provide a printed circuit board mounting structure in which soldering between printed circuit boards can be easily removed during repairs after assembly is completed.

[Disclosure of invention]

The present invention will be explained below using examples.

Figures 2 and 3 show one embodiment, and in the figures, 1a and 1b are printed circuit boards arranged in parallel at the top and bottom, and cutouts 2 are provided at both ends of these printed circuit boards 1a and 1b, respectively. It is formed. 3a and 3b are printed circuit boards arranged in a direction perpendicular to the printed circuit boards 1a and 1b by fitting protrusions 4a and 4b formed at the upper and lower ends into the upper and lower opposing notches 2 and 2, respectively. be. However, the printed circuit boards 1a, 1b, 3a, and 3b have a mounting structure in which they are three-dimensionally connected in a frame shape. Reference numeral 7 denotes a terminal block, and the engaging protrusion 7a of this terminal block 7 is coupled to the notch 2 and abuts on the lower surface of the printed circuit board 1a, and is placed on the upper surface of the printed circuit board 1b, and furthermore,
The side ends of a are connected to each other and placed on the front surface side of the printed circuit board 3a. Printed circuit boards 1a and 1b,
Electrical connections with 3a and 3b are made using connection patterns 5 and 6.
This is done using connection pattern 5,
6 has a positional relationship as shown in FIG.

That is, for example, the mechanical soldering strength is lost between the connection pattern 6 of the protrusion 4 of the printed circuit board 3a fitted into the notch 2 of the printed circuit board 1a and the connection pattern 5 facing the inner end of the notch 2 of the printed circuit board 1a. The printed circuit board 3 should be
The fitting degree of the protruding portion 4 of a is set. In the embodiment, the connection positional relationship between the terminal block 7 and the printed circuit board 3a, the surfaces located on both sides of the engaging protrusion 7a of the terminal block 7 that fits into the notch 2, and the end surfaces of the printed circuit board 3a on both sides of the notch 2 are shown. It is determined by the contact between the

Of course, as shown in FIG. 4, step portions 2a are provided on both sides of the rear end of the notch 2, and a protrusion 2b is provided in the center, and the fitting position of the protrusion 4a of the printed circuit board 3a is determined by the step portions 2a and the protrusion 2b. Alternatively, the gap t may be secured by performing the following steps. In this embodiment, the protrusion 4a of the printed circuit board 3b on the side where the terminal block 7 is not provided
It is suitable as a means for determining the positional relationship between the connection pattern 6 of the circuit board 1a and the connection pattern 5 of the printed circuit boards 1a and 1b. Of course, the central protrusion 2b may be eliminated and positioning may be performed using only the stepped portions 2a, 2a on both sides.

Furthermore, as shown in FIG. 5, a protrusion 8 penetrating the printed circuit board 3a is provided on the engagement protrusion 7a of the terminal block 7, and by abutting the protrusion 8 against the rear end surface of the notch 2, the engagement protrusion 7a is closed. The protruding portion 4 of the printed circuit board 3a that is in contact with the tip end surface is the engaging protruding portion 7a.
At the same time, the position may be restricted so that it does not advance toward the rear end of the notch 2.

Furthermore, connection pattern 5 facing the far end of notch 2
As shown in FIG. 6, a solder resist may be applied to the connection pattern 5 outside the frame surrounded by the broken line a to obtain a gap t where no solder is applied.

[Effect of idea]

In the printed circuit board mounting structure constructed as described above, the present invention provides a structure in which the mechanical soldering strength is not impaired between the connection patterns for soldering between the printed circuit boards arranged at fixed positions so as to be substantially perpendicular to each other. Since a gap is provided, when the solder applied between the connection patterns is melted, the solder between the connection patterns can be easily and completely separated without capillarity occurring due to the gap, thus forming the connection pattern. This invention has the excellent advantage that it is possible to repair the copper foil without causing any damage caused by peeling it off from the board, and it also increases work efficiency because the solder can be easily separated. It has the effect that it can be reused 4 to 6 times, which is approximately 3 to 4 times as many times as the conventional example, under the same conditions as the conventional configuration described above, and in terms of separation work efficiency, it is difficult to check whether separation has occurred at any time. It can be easily determined just by looking at the presence or absence of the solder, and it can be completely separated with a single solder melting operation, resulting in an improvement of more than twice that of the conventional example, and the larger the number of connection patterns, the more The effect is remarkable.

[Brief explanation of the drawing]

FIG. 1 is an enlarged perspective view of a conventional example with some parts omitted; FIG. 2 is an overall perspective view of an embodiment of the present invention; FIG. 4 to 6 are enlarged sectional views, partially omitted, for explaining the main parts of other embodiments of the present invention;
1b, 3a, 3b are printed circuit boards, 5, 6 are connection patterns, and t is a gap.

Claims (1)

[Scope of utility model registration request] In a printed circuit board mounting structure in which a plurality of printed circuit boards are arranged in directions substantially orthogonal to each other and the connection patterns provided on each of the substantially orthogonal printed circuit boards are soldered to each other to electrically connect the printed circuit boards, substantially orthogonal A printed circuit board mounting structure comprising a gap that does not impair mechanical soldering strength between the connection patterns for soldering between printed circuit boards arranged at fixed positions.