JP2006019110A - Circuit board connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit board connector in which there is no possibility of impairing the mechanical strength of a circuit board by moderating stress surely even if large stress is generated in a connecting part with a through-hole formed at a circuit board terminal and the circuit board due to a difference in a thermal expansion coefficient between an insulation housing of the circuit board connector and the circuit board. <P>SOLUTION: In the circuit board connector 1 which has the insulation housing 4 fixed to the circuit board 3, and the circuit board terminal 2 protruded from the insulation housing 4, the circuit board terminal 2 is curved into a nearly L-shape and has a bending part 5, and its one end penetrates through the insulation housing 4 to form a connector connection terminal 6 electrically connected to the counter connector, and the other end forms a circuit board circuit connection terminal 8 soldered to the through-hole 9 formed in the circuit board 3, and the bending part 5 forms a stress relaxation part 5 which is formed thinner than the other part of the circuit board terminal 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an improvement of a board connector mounted on a circuit board.

In recent years, for example, in the automobile industry, the wiring material of electrical connection boxes has been made into a board, and the number of connection terminals on the circuit board is rapidly increasing, such as power supply into the circuit board, integration of components, batch connection of connectors, etc. Is going on.
As a result, board connectors connected to the circuit board have also become multipolar, and a board in which many board terminals are incorporated in an elongated insulating housing has begun to be mounted on the circuit board.
Among them, a small type of signal input / output unit of an electronic circuit has been mounted so far, but in the future, there is a demand for incorporating power distribution into the circuit board part.

By the way, in a board connector in which many terminals are incorporated in this type of elongated insulating housing, for example, the circuit board may be exposed to a high and low temperature intense atmosphere as in an in-vehicle environment. In such a case, due to the difference in thermal expansion coefficient between the insulating housing and the circuit board, stress may be applied to the board terminal and distortion may occur. Further, even when the circuit board generates heat due to energization, distortion due to a difference in thermal expansion may occur between the circuit board and the insulating housing.
As a result, a large stress is applied to the soldered connection between the pad or through hole provided on the circuit board and the board terminal, which may cause distortion.

  In general, board connectors are mounted on circuit boards, screwed, and soldered by flow soldering, etc., but if they are connected slightly off at this time, they will be exposed when exposed to a cold atmosphere. There is also a risk of promoting the generation of stress and strain due to expansion differences.

Therefore, a stress relaxation part is formed in the middle of the substrate terminal, and the stress described above is relaxed by this stress relaxation part so that a large stress is not applied to the connection part between the substrate terminal and the circuit board (Patent Document 1).
As shown in FIG. 2, the device described in Patent Document 1 forms a bent portion 5 in the middle of a board terminal 2 projecting outward from the insulating housing 4 of the board connector 1, and The circuit board 3 is provided with a retraction hole 15 as a relief part of the stress relaxation part 5 and as a relief part of the stress relaxation part 5 and for regulating the lateral vibration of the board connector 1 with respect to the circuit board 3.

In FIG. 2, reference numeral 8 denotes a front end portion of the board terminal 2, which is a board circuit connection terminal soldered to the pad 7 provided on the circuit board 3, and its lower surface is a connection surface 8 a with the pad 7. It has become.
Reference numeral 12 denotes a screw fastening portion provided on the side surface of the insulating housing 4, and the board connector 1 is fixed to the circuit board 3 by fastening the screw 10 into the screw hole of the screw fastening portion 12.

In the board connector 1 shown in FIG. 2, for example, stress caused by vibration or temperature difference or stress generated when the board connector 1 is attached to or detached from the circuit board 3 is the bent portion, In other words, when the board connector 1 is fixed to the circuit board 3 with the screw 10 when the board connector 1 is fixed to the circuit board 3 by the stress relaxation portion 5, even if the board connector 1 is swung in the tightening direction around the screw 10, the retraction provided on the circuit board 3 is performed. The stress relaxation portion 5 retracted in the hole 15 regulates this shake.
As a result, the occurrence of stress on the connection portion between the front end portion of the substrate terminal 2 and the pad 7 of the substrate circuit connection terminal 8 is prevented, and the connection between the substrate circuit connection terminal 8 and the pad 7 is impaired, or the substrate circuit connection The possibility that the pads 7 together with the terminals 8 and the circuit pattern connected thereto will be peeled off from the circuit board 3 is also avoided.

JP 7-153508 A

By the way, when estimating from the example, Patent Document 1 has a relatively small number of poles and a small size of the board terminal, so that the length of the insulating housing is short and hardly affected by the thermal expansion coefficient due to the temperature difference.
If this structure is applied to a large terminal used in a long-side multipolar connector, the terminal width is constant, so the stress in the plate width direction of the board terminal 2 is difficult to relax and is applied to the soldered portion. The stress becomes excessive and the soldered part may be destroyed.
Even if the stress can be relieved by the stress relieving portion 5, there is a possibility that the retraction hole 15 and the substrate terminal 2 come into contact with each other due to the displacement of the terminal portion, and in that case, the circuit board 3 may be destroyed. In order to avoid this problem, it is necessary to make the escape hole 15 large in order to avoid contact with the board terminal 2. However, if the escape hole 15 is made large, the wiring space of the circuit board 3 is reduced and the circuit There is also a risk of impairing the rigidity of the substrate 3.

The so-called insulating housing 4 and circuit board 3 when the insulating housing 4 and the circuit board 3 of the board connector 1 are in a cold atmosphere or when the circuit of the board terminal 2 and the circuit board 3 is self-heated by energization. Patent Document 1 does not mention anything about the problem of stress generation due to the difference in thermal expansion coefficient between the two, but if stress is generated due to a high temperature or low temperature environment, it is perpendicular to the circuit board 3. Although the stress may be relieved by the bending portion, that is, the stress relieving portion 5, the plate width of the substrate terminal 2 as described above is applied to the stress in the longitudinal direction of the board connector 1, that is, the longitudinal direction of the insulating housing 4. Since the size of the direction is constant, it is presumed that when the terminal is made large, it is difficult to twist and the stress cannot be relieved.
In addition, even when twisted, the retraction hole 15 may be contacted and regulated, and the stress relaxation effect due to twisting may not be exhibited.

  Further, when the retraction hole 15 is provided for each stress relaxation portion 5 provided in the middle of each multipolar board terminal 2, there is a risk that the circuit board 3 becomes full of holes and the mechanical strength of the circuit board 3 itself is impaired. If the number of retraction holes 15 is high, the wiring space is narrowed. Therefore, it is very difficult to form a wiring circuit on the board terminal 2, and the possibility of actually wiring the circuit is very low. Become.

  Further, in the case shown in FIG. 2, the bending of the substrate terminal 2 from the horizontal direction to the vertical direction and the bending for forming the stress relieving portion 5 are required twice, and the processing cost is required. There is also a problem that becomes higher.

  In view of the above problems, the object of the present invention is to connect a board terminal incorporated in an insulating housing and a pad or a through hole provided on the circuit board, in particular, due to a difference in thermal expansion coefficient between the insulating housing of the board connector and the circuit board. Even if a large stress is likely to occur on the board, it is a board connector that can alleviate this surely and reduce the mechanical strength of the circuit board, and can easily process board terminals and reduce costs. To provide a connector.

  To achieve the above object, the board connector according to claim 1, wherein the board connector includes an insulating housing fixed to the circuit board and a board terminal protruding from the insulating housing, and the board terminal is substantially L-shaped. A bent portion, one end of which forms a connector connection terminal that penetrates the insulating housing and is electrically connected to the mating connector, and the other end is a pad or a through hole formed on the circuit board. A board circuit connection terminal to be soldered to the board terminal, and the bent part is formed to be thinner than other parts of the board terminal to form a stress relaxation part for relaxing the stress generated in the board terminal. It is characterized by.

According to the substrate connector of claim 1, the substrate terminal is bent in a substantially L shape and has a bent portion, and the bent portion is formed narrower than other portions of the substrate terminal. Acts like a spring. Therefore, the bent portion acts as a stress relaxation portion that reliably relaxes stress generated in the board terminal, particularly stress in the longitudinal direction of the board connector, that is, in the longitudinal direction of the insulating housing.
Therefore, due to the difference in the thermal expansion coefficient between the insulating housing of the board connector and the circuit board, the insulating housing is particularly connected to the connection portion between the circuit board board terminal at the tip of the board terminal and the pad or through hole provided on the circuit board. Even if a large stress in the longitudinal direction is likely to occur, this is surely alleviated.

In addition, in the board terminal for the board connector of the present invention, the stress relaxation portion can be formed only by thinning a part of the board terminal. That is, since the stress relaxation portion can be formed by bending once in the same manner as in the prior art, a part obtained by punching a part of the board terminal in advance, so that the cost of the board connector can be reduced. In addition, as shown in FIG. 2, there is no need to make a special work such as a retraction hole on the circuit board side, so there is no possibility of damaging the mechanical strength of the circuit board.
In addition to the shape of the board terminal on the connection side with the circuit board, the spring part, that is, the thinned part is minimized and the remaining part is thickened to suppress self-heating and temperature rise due to energization, and soldering The rigidity of the portion to be improved can be increased, the distortion of the solder itself can be reduced, and further, the shear stress due to the expansion of the contact area with the solder can be reduced.

  As described above, according to the present invention, due to the difference in the thermal expansion coefficient between the insulating housing of the board connector and the circuit board, the connection between the board terminal incorporated in the insulating housing and the pad or through hole provided on the circuit board is particularly important. Even if a large stress is likely to occur on the board, it is a board connector that can alleviate this surely and reduce the mechanical strength of the circuit board, and can easily process board terminals and reduce costs. A connector can be provided.

  Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of a board terminal for a board connector according to the present invention. In FIG. 1, only one board terminal 2 is written in the insulating housing 4 so as not to be complicated, but actually, a plurality of board terminals 2 are arranged in a row or in multiple stages in the longitudinal direction of the insulating housing 4. 4 is penetrated. The same components as those in FIG. 2 described above are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in FIG. 1, the board terminal 2 for the board connector 1 of the present invention protrudes from the insulating housing 4 of the board connector 1 fixed to the circuit board 3. The substrate terminal 2 is bent in a substantially L shape in the middle thereof to form a bent portion 5.
The board terminal 2 has a tab-like connector connection terminal 6 that penetrates the insulating housing 4 and is electrically connected to a mating connector (not shown) at one end, and is formed on the circuit board 3 at the other end. A substrate circuit connection terminal 8 is soldered to the through hole 9.

Incidentally, as shown in FIG. 1, the bent portion 5 is formed so that the size of the board terminal 2 in the width direction of the board is narrower than that of the other parts and is provided with a spring property. 3 and the insulating housing 4, the stress generated in the connecting portion between the through hole 9 and the substrate circuit connecting terminal 8 due to the difference in thermal expansion coefficient between the insulating housing 4, particularly the stress in the longitudinal direction of the insulating housing 4, is applied to the thin bent portion 5 ( The stress load on the connecting portion between the through hole 9 and the substrate circuit connecting terminal 8 can be greatly reduced.
Here, reference numeral 10 denotes a screw, and the board connector 1 is fixed to the circuit board 3 by tightening the screw 10.

  By the way, in the embodiment, the board circuit connection terminal 8 of the board terminal 2 is soldered to the through hole 9 of the circuit board 3, but the board circuit connection terminal is connected to the pad provided on the circuit board 3 instead of the through hole 9. 8 may be placed and soldered.

  In addition, the board terminal 2 shown in the embodiment is formed by punching out a die of the board terminal 2 whose part is previously narrowed by punching and bending it into an L shape at only one place like a normal board terminal. A substrate terminal 2 having a bent portion 5 (stress relaxation portion 5) shown in FIG. Therefore, if the die for punching is made, the board terminal 2 can be manufactured with the same number of processing steps as that in which the conventional stress relaxation portion 5 does not exist, so that the low-cost board connector 1 can be provided.

  As described above, according to the present invention, due to the difference in the thermal expansion coefficient between the insulating housing of the board connector and the circuit board, the connection between the board terminal incorporated in the insulating housing and the pad or through hole provided on the circuit board is particularly important. Even if a large stress is likely to be generated in the portion, it is possible to provide a board connector that can alleviate this surely and reduce the mechanical strength of the circuit board. In addition, since the processing of the board terminals is easy, a low-cost board connector can be provided.

It is a perspective view which shows one Example of the board | substrate connector of this invention. It is a perspective view which shows the conventional board | substrate connector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board connector 2 Board terminal 3 Circuit board 4 Insulation housing 5 Bending part (stress relaxation part)
6 Connector connection terminal 8 Substrate circuit connection terminal 9 Through hole

Claims (1)

  In a board connector having an insulating housing fixed to a circuit board, and a board terminal protruding from the insulating housing, the board terminal is bent in a substantially L shape and has a bent portion, and one end of the board terminal is the insulating board. A connector connection terminal that is electrically connected to the mating connector through the housing is formed, and the other end is a substrate circuit connection terminal that is soldered to a through hole or pad formed in the circuit board, The board connector is characterized in that the bent part is formed thinner than the other part of the board terminal and forms a stress relaxation part for relaxing the stress generated in the board terminal.

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