JP6943690B2 - Printed board - Google Patents

Description

The present invention relates to a printed circuit board formed by combining a main board and a sub-board, and more particularly to a printed circuit board capable of stably and efficiently attaching the sub-board to the main board.

Products are also becoming smaller in the field of electronic circuits. When a sub-board is provided on a printed circuit board for the purpose of small signals, etc., when fixing the sub-board to the main board of the printed circuit board, the sub-board is directly mounted on the main board without using components such as connectors. The method of inserting into is known.

However, the mounting groove (slit) opened in the main board for inserting the sub board needs to prevent "rattling" at the joint portion between the two when the sub board is mounted. For that purpose, it is desirable to minimize the gap (clearance) between the slit of the main substrate and the surface of the sub substrate. However, since there are tolerances in the slits of the main board, that is, the size of the opening and the plate thickness of the sub board, it is necessary to design with a certain gap, and this gap (clearance) is when the sub board is attached. It causes "rattle" of.

When the sub-board is soldered to the main board, this "rattling" gap is fixed by the solder. However, when the printed circuit board as a product vibrates as a whole, the sub-board also vibrates. However, in a structure in which the sub-board is inserted into the slit of the main board, when the sub-board vibrates, the impact is concentrated on the soldered portion. Therefore, in order to avoid such a situation, it is possible to prevent "rattle" between the main board and the sub board when vibration occurs, and the conductive pattern between the sub board and the main board is joined. It is necessary to reduce the impact (stress) on the solder to extend the life and improve the quality of the product.

In Patent Document 1, terminal pads for solder connection to the mother board (main board) are provided on both the front and back sides of the lower part of the auxiliary board (sub board), and the auxiliary board (sub board) is formed in a slit made in the mother board (main board). The structure is disclosed in which the solder is directly inserted and connected. Then, in the slit, a portion having a width of the first slit for solder connection with the auxiliary substrate (sub-board) and a first for holding the auxiliary substrate (sub-board) substantially perpendicular to the mother substrate (main board). It is disclosed that a portion having a two-slit width is provided, the first slit width A is larger than the second slit width, and the second slit width is substantially equal to or less than the thickness of the auxiliary substrate (sub-board).

In Patent Document 2, a mounting hole is provided at the joint portion between the sub-board and the main board, the plug pin is penetrated perpendicularly to the sub-board, and the plug pin and the wiring pattern of the sub-board are soldered to form the mounting hole of the main board. A structure is disclosed in which the wiring patterns of the connection piece inserted into the main board and the main board are soldered to increase the mechanical strength of the printed circuit board (wiring board).

Further, Cited Document 3 discloses a configuration similar to that of Cited Document 2, and the main of the sub-board is formed by arranging jumper wires instead of terminals on the sub-board terminal portion and soldering both sides of the sub-board. Those that increase the mechanical strength while preventing erroneous insertion into the substrate are disclosed.

Japanese Unexamined Patent Publication No. 2004-153178 Japanese Unexamined Patent Publication No. 5-198911 Japanese Unexamined Patent Publication No. 5-198910

It can be considered that the problem of "rattling" can be solved by the one disclosed in Patent Document 1. However, since there are many parts that are equal to or less than the thickness of the sub-board, when the sub-board is inserted into the slit of the main board, the load of press-fitting operation becomes heavier, or the interference parts of the slits are damaged. Another problem arises: it is easier to do.

Further, the problem that the load on the solder connecting the sub-board and the main board due to the vibration of the sub-board becomes large cannot be solved yet.

The structure disclosed in Cited Document 2 has a problem that the number of steps for specially processing the sub-board insertion opening (slit) of the sub-board and the main board is increased.

Similarly, in Cited Document 3, there is a problem that the number of steps for specially processing the opening of the main substrate is increased.

Therefore, the present invention provides a printed circuit board that can reduce the burden of coupling operation between the sub-board and the main board as much as possible and also reduce the load on the solder that connects the conductive patterns of the main board and the sub-board. The purpose is to provide.

The above object of the present invention is to provide a main board on which electronic components are arranged.
In a printed circuit board provided with a sub-board that serves as an auxiliary role of the main board and an engaging member made of a conductive material attached to the conductive pattern of the sub-board.
The sub-board can be combined with the main board by being inserted into a slit forming an opening provided in the main board.
One end side of the engaging member is fixed to the conductive pattern of the sub-board, and the other end side is a free end. When the sub-board is inserted into the main board and combined, the sub-board is engaged. The member and the slit of the main substrate form an engaging relationship, and the member and the slit of the main substrate form an engaging relationship.
This can be achieved with a printed circuit board in which the engaging member and the conductive pattern of the main board are solder-bonded after the insertion operation is completed.

In a preferred embodiment, when the sub-board is inserted into the main board, the engaging member includes a claw portion that sandwiches the main board from the inside of the slit of the main board.

In another aspect, the engaging member may include a protrusion that is in contact with the inside of the slit of the main board when the sub-board is inserted into the main board.

According to the present invention, in a printed circuit board having a main board and a sub board and having a structure in which the sub board is inserted into a slit provided in the main board, the main board and the sub board are subjected to a load such as vibration or impact. The rattling between the substrate and the substrate can be effectively suppressed. At the same time, since the engaging member is attached to the conductive pattern of the sub-board and soldering is performed including the engaging member, the stress load of the solder connecting the conductive pattern of the substrate and the sub-board can be reduced.

It is a perspective view which shows the main board which constitutes the printed circuit board which concerns on one Example of this invention, and the sub-board which attached the engaging member. FIG. 5 is a cross-sectional view showing a state after the sub-board is inserted into the main board and further soldered in the printed circuit board of FIG. 1. It is the same cross-sectional view as FIG. 2 which concerns on another Example.

Hereinafter, the present invention will be described with reference to the drawings based on examples. With reference to FIG. 1, a perspective view of the main board 20 and the sub board 30 constituting the printed circuit board 10 from the component side is shown. FIG. 1 shows a state of the sub-board 30 that is about to be inserted into the slit 21 of the main board 20 from the component surface side. The sub-board 30 of this example is generally longer than the length of the slit 21 in the longitudinal direction. The tip of the central portion of the sub-board 30 on the insertion side has a protruding shape, and the protruding portion is smaller than the length of the slit 21 in the longitudinal direction.

This protruding portion constitutes an insertion portion 31 of the sub-board 30 that is inserted into the slit 21 of the main board 20. That is, both sides of the insertion portion 31 of the sub-board 30 form shoulder portions 32, 32 protruding outward. The width of the slit 21 is set to be slightly larger than the thickness of the sub-board 30 as a whole in consideration of the efficiency of the insertion work.

Further, a plurality of conductive patterns 33 are formed on the side surface of the sub-board 30 of this example, and a conductive engaging member 40 is attached to each of the conductive patterns 33. In this example, the engaging member 40 is adhered to the conductive pattern 33 of the sub-board 30 by reflow soldering (not shown). The engaging member 40 of this example is formed by processing a flat plate 41. A pair of claw-shaped protrusions 42, 42 are formed at both ends of the flat plate 41 constituting the raw material of the engaging member 40 according to this example.

In this state, the engaging member 40 of this example is attached to the conductive pattern 33 of the sub-board 30 by reflow soldering on the back surface forming the thickness thereof.

In this example, the conductive patterns 33 are formed on both side surfaces of the sub-board 30, and the conductive engaging member 40 is attached to the conductive pattern 33 in the attached state as described above. In the state before the sub-board 30 is inserted into the slit 21 of the main board 20, the engaging members 40 are attached to both side surfaces of the sub-board 30, and the thickness of the sub-board 30 in that state. That is, the distance between the tips of the engaging members 40 attached to both side surfaces is larger than the width of the slit 21.

Therefore, when the sub-board 30 is inserted into the slit 21 of the main board 20, the pair of tips of the claw-shaped protrusions 42, 42 at both ends of the engaging member 40 move while being in contact with the inner surface of the slit. In some cases, the slit 21 is moved while scraping the inner surface or deforming a pair of tips of the claw-shaped protrusions 42, 42. Then, when the insertion of the engaging member 40 integrated with the insertion portion 31 of the sub-board 30 is completed, the claw-shaped protrusions 42, 42 of the sub-board 30 insert the main board 20 from the inside of the slit 21 from both sides. The sub-board 30 is incorporated into the main board 20 in a sandwiched state.

With reference to FIG. 2, a state in which the sub-board 30 is inserted into the slit 21 of the main board 20 is explanatoryly shown in the form of a cross-sectional view.

As shown in the figure, the conductive pattern 23 is also provided on the solder surface side of the main substrate 20 at a position corresponding to the conductive pattern 33 of the sub substrate 30.

Here, what is important is that the tips of the claw-shaped protrusions 42, 42 of the engaging member 40 attached to the sub-board 30 are pressed against the conductive pattern 23 on the solder surface side of the main board 20. .. That is, in FIG. 2, the sub-board 30 is formed so that the main board 20 is sandwiched between the pair of claw-shaped protrusions 42, 42 by pressure from the claw-shaped protrusions 42, 42 of the engaging member 40. The substrate 30 is held by the main substrate 20.

Further, when the slit 21 is processed by pressing with a die, the central portion of the slit 21 is finished in a slightly expanded state in the cross section, so that the central portion is recessed like the engaging member 40 of this example. By having the above, the degree of adhesion can be improved.

In this state, the conductive pattern 23 of the main substrate 20 and the terminal portion of the conductive pattern 33 formed on the surface of the sub substrate 30 are soldered.

The state of FIG. 2 is a state after inserting the sub-board 30 into the slit 21 of the main board 20 while pressing the engaging member 40, and further soldering with the solder 50. Since soldering is performed on the solder side, the state of the printed circuit board 10 as seen from the component side does not change even after soldering. As shown in FIG. 2, the solder 50 integrates the engaging member 40 and connects the terminal portion of the conductive pattern 23 of the main substrate 20 and the conductive pattern 33 formed on the surface of the sub substrate 30.

As a result, the sub-board 30 is held by the main board 20 in a state where there is no "rattling" which has been a problem in the past, and the conductive patterns 23 and 33 of the main board 20 and the sub-board 30 are soldered. The sub-board 30 can be firmly fixed to the main board 20. Therefore, even when vibration, impact, or the like is applied to the printed circuit board 10, the stress load applied to the solder 50 between the terminals can be effectively suppressed.

FIG. 3 shows another embodiment of the present invention. As shown in FIG. 3, the flat plate 61 constituting the raw material of the engaging member 60 of this example has a structure including a plurality of tooth profiles 62 having sharp tips.

In this example, in the state after the sub-board 30 is inserted into the slit 21 of the main board 20, the portion of the tooth profile 62 at the tip of the engaging member 60 is in contact with the inner surface of the slit 21 as shown in the figure. In this state, the sub-board 30 and the main board 20 are coupled. Then, after the two are bonded, the conductive patterns 23 and 33 of the main substrate 20 and the sub substrate 30 are soldered so that the solder 50 integrally bonds the conductive patterns 23 and 33 as shown in the figure.

In addition to the embodiments shown in this example, engaging members having various shapes within the range described in the claims can be used.

10 Printed circuit board 20 Main board 21 Slit 32 Shoulder 23 Conductive pattern (copper foil)
30 Sub-board 33 Conductive pattern 40 Engagement member 41 Raw material 50 Solder 60 Engagement member

Claims (1)

The main board on which electronic components are placed and
In a printed circuit board provided with a sub-board that serves as an auxiliary role of the main board and an engaging member made of a conductive material attached to the conductive pattern of the sub-board.
The sub-board can be combined with the main board by being inserted into a slit forming an opening provided in the main board.
The engaging member is fixed to the conductive pattern of the sub-board, the sub-board is inserted into the main board, and the engaging member of the sub-board and the slit of the main board form an engaging relationship.
The engaging member includes at least a pair of protruding portions, the main substrate is sandwiched from the inside of the slit by the protruding portions , and after the insertion operation is completed, the engaging member and the conductive pattern of the main substrate are combined. A printed circuit board that is solder-bonded between them.

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