JPH08167765A - Structure for connecting circuit part with wiring board - Google Patents

Abstract

PURPOSE: To provide a structure whereby the connecting of a circuit part with the wiring pattern of a wiring board is not damaged even in the situation wherein their temperatures are varied largely. CONSTITUTION: A circuit part 14 is provided on a wiring board 10 while its lead terminal 14a is stuck into the wiring board 10. One end section of a connecting conductor 34 is fastened by soldering 16 to the lead terminal 14a protruded from the wiring board 10, and the other end of the connecting conductor 34 is fastened by soldering 16 to a wiring pattern 12 while its length leaves a margin by its meandering or relaxing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure for a wiring board and a circuit component, which is suitable for being incorporated in an apparatus exposed to an environment where the temperature greatly changes.

[0002]

2. Description of the Related Art As shown in FIG. 3A, a conventional connection structure between a wiring board and circuit parts has a HIC (Hybrid Integrated Circuit) structure on the surface of the wiring board 10 opposite to the surface on which the wiring patterns 12 are provided. Circuit components 14)
Are arranged, and the lead terminals 14a led out from the circuit component 14 are passed through the wiring substrate 10 to form the wiring pattern 12
Of the lead terminal 14a itself is connected and fixed to the wiring pattern 12 by soldering 16.

[0003]

In the conventional connection structure of the wiring board and the circuit component as described above, the following problems occur under the environment where the temperature changes drastically. First, when exposed to a high temperature, the lead terminal 14a slightly extends in the length direction and the tip end is fixed to the wiring pattern 12 by soldering 16.
A force acts in a direction of separating the circuit component 14 from the wiring board 10. Here, if the circuit component 14 can be separated from the wiring board 10, no problem will occur if the plurality of lead terminals 14a led out from the circuit component 14 extend by the same size, respectively. There is variation, and an excessive force that tends to shift in the length direction acts between the lead terminal 14a and the soldering 16. Further, if the circuit component 14 cannot be separated from the wiring board 10, the circuit component 14 is likely to receive an excessive force in the compression direction at the base end portion of the lead terminal 14a.
And, in the situation of being exposed to low temperature, the lead terminal 1
4a slightly contracts in the length direction, and the circuit component 14 is likely to receive an excessive force in the pulling direction between the lead terminal 14a and the soldering 16 and at the base end portion of the lead terminal 14a.

Thus, due to a large change in temperature,
As shown in FIG. 3B, a crack 18 may occur between the lead terminal 14a and the soldering 16, and finally the electrical connection between the lead terminal 14a and the soldering 16 may be incomplete. If the lead terminal 14a and the soldering 16 are firmly welded, as shown in FIG. 3 (c),
The extension of the lead terminal 14a may cause the wiring pattern 12 to be peeled off 20 from the wiring substrate 10, and eventually the wiring pattern 12 may be broken.

If the entire circuit is housed in a case having an excellent heat insulating effect in order to suppress the adverse effects of these large changes in temperature, the effects of sudden changes in temperature can be mitigated. However, no effect can be obtained in cases and the like for moderate and large temperature changes.

The present invention has been made to solve the problems of the prior art as described above, and a wiring board and a circuit in which the connection structure is not damaged even when the temperature changes drastically. An object is to provide a connecting structure for parts.

[0007]

In order to achieve such an object, in the connection structure of the wiring board and the circuit component of the present invention, the circuit component is provided on the surface opposite to the surface on which the wiring pattern of the wiring board is provided. While arranging the lead terminals, the lead terminals derived from the circuit parts are projected through the wiring board to the surface on which the wiring pattern is provided, and one end of the connecting conductor is electrically connected to the projected lead terminals. The connection conductor is fixed, and the other end is soldered and fixed to the wiring pattern with a margin in length.

Then, one end of the connecting conductor is wound in a coil shape, the tip portion of the lead terminal is fitted into this coil portion, and a part of the tip end side of the coil portion is fixed to the lead terminal by soldering. May be configured.

Further, the circuit component may be supported on the wiring board by a leaf spring fixed to the wiring board.

[0010]

[Operation] One end of the connection conductor was electrically connected and fixed to the lead terminal derived from the circuit component, and this connection conductor was fixed by soldering the other end to the wiring pattern with a margin in length. Even if the lead terminal expands or contracts with a large change in temperature, the connection conductor can be deformed with a sufficient length, and the change in the length of the lead terminal can be sufficiently absorbed. Therefore, an excessive force does not act on the wiring pattern.

If one end of the connecting conductor is wound into a coil and the tip of the lead terminal fitted in the coil is soldered to a portion of the tip of the coil, the coil is formed. The elastic deformation in the axial direction can absorb the expansion and contraction changes of the lead terminal. Moreover, the lead terminals are not swung and come into contact with other parts.

Furthermore, if the circuit component is elastically supported on the wiring board by a leaf spring, the circuit component will not be damaged even if the external dimensions of the circuit component itself change due to a large temperature change.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a vertical cross-sectional view of an embodiment of a connection structure between a wiring board and circuit components of the present invention.

In FIG. 1, the circuit component 14 is arranged on the surface of the wiring board 10 opposite to the surface on which the wiring pattern 12 is provided via the spacer 30, and the circuit is formed by the leaf spring 32 fixed to the wiring board 10. The component 14 is elastically supported. The lead terminal 14a derived from the circuit component 14 is
The wiring pattern 12 penetrates through the wiring board 10
Is projected on the surface provided with. One end of a flexible connecting conductor 34 is fixed by soldering 16 to the tip of the projecting lead terminal 14a. Further, the connecting conductor 34 has a margin in length, for example, is slightly meandered or loosened, and the other end is fixed to the wiring pattern 12 by soldering 16.

In such a structure, since the connecting conductor 34 has a margin in length with respect to the change in length of the lead terminal 14a extending and contracting due to a great change in temperature, the connecting conductor 34 is deformed. Thus, the change in length of the lead terminal 14a is absorbed. Therefore, no excessive force acts on the wiring pattern 12. Therefore, the electrical connection between the lead terminal 14a and the wiring pattern 12 is not damaged. Further, the circuit component 14 itself does not receive an excessive force due to the change in the length of the lead terminal 14a. In addition, the circuit component 14
Is elastically supported by the leaf spring 32, so that the circuit component 14 will not be damaged even if the external dimensions of the circuit component 14 itself change due to temperature changes.

FIG. 2 is a vertical cross-sectional view of another embodiment of the connection structure of the wiring board and the circuit component of the present invention. 2 is different from the embodiment shown in FIG. 1 in that one end portion of the connection conductor 34 is wound in a coil shape, and the tip end portion of the lead terminal 14a is wound around the coiled portion 34a. A part of the coil-shaped portion 34a on the tip side is fixed to the lead terminal 14a by soldering 16. It is desirable that the coil-shaped portion 34a has a gap between pitches so that the coil-shaped portion 34a can expand and contract in the coil axial direction.

In such a structure, the lead terminal 14a
Can be dealt with by expanding and contracting the coiled portion 34a in the coil axial direction. Therefore, a large margin is not required for the apparent length of the connection conductor 34 from the coiled portion 34a to the other end fixed to the wiring pattern 12. Therefore, the connecting conductor 34 does not come into contact with other parts due to swinging or the like to cause a short circuit accident or the like.

In the embodiment shown in FIG. 2, the coiled portion 34a of the connecting conductor 34 is formed so that the winding inner diameter thereof is smaller than the outer diameter of the lead terminal 14a, so that the elasticity of the coiled portion 34a itself leads the lead. The terminal 14a can be securely electrically connected and fixed.

In the above embodiment, the wiring board 1
No wiring pattern is provided on the surface on which the circuit component 14 of No. 0 is provided, but it goes without saying that a wiring pattern other than the one to which the lead terminal 14a is connected may be provided. Further, the circuit component 14 is not limited to the HIC or the like, and may be any circuit component that is electrically connected to the wiring pattern 12 by the lead terminal 14a penetrating the wiring substrate 10. Furthermore, the circuit component 14
The structure for supporting the wiring board 10 on the wiring board 10 is not limited to the leaf spring 32, and may be fixed by a bolt / nut or an adhesive.

[0020]

As described above, since the connection structure of the wiring board and the circuit component of the present invention is constructed, the following special effects are exhibited.

In the connection structure of the wiring board and the circuit component according to the first aspect, the change in the length of expansion and contraction of the lead terminal due to the temperature change is absorbed by the deformation of the connecting conductor having a sufficient length. As a result, excessive force does not act on the wiring pattern and circuit parts, and the connection structure is not damaged.

In the connection structure of the wiring board and the circuit component according to the second aspect, the change in length of the lead terminal can be absorbed by the coil-shaped portion provided at one end of the connection conductor. Therefore, the connection conductor does not require a large allowance in appearance, and the connection conductor does not unnecessarily swing and come into contact with other components.

Further, in the connection structure of the wiring board and the circuit component according to the third aspect, since the circuit component is elastically supported, the outer dimension of the circuit component itself is changed due to the temperature change. Also, it is absorbed by the deformation of the leaf spring, and the circuit components are not damaged.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an embodiment of a connection structure of a wiring board and circuit components of the present invention.

FIG. 2 is a vertical sectional view of another embodiment of the connection structure of the wiring board and the circuit component of the present invention.

FIG. 3 (a) is a vertical cross-sectional view of a conventional connection structure between a wiring board and a circuit component, and FIG. 3 (b) shows a crack between a lead terminal and a solder due to a large change in temperature. FIG. 4C is a vertical cross-sectional view showing an example, and FIG. 6C is a vertical cross-sectional view showing an example in which the wiring pattern is peeled off from the wiring board due to a large change in temperature.

[Explanation of symbols]

 10 wiring board 12 wiring pattern 14 circuit component 14a lead terminal 16 soldering 32 leaf spring 34 connection conductor 34a coiled portion

Claims (3)

[Claims] 1. A circuit component is disposed on a surface of a wiring substrate opposite to a surface on which the wiring pattern is provided, and lead terminals derived from the circuit component are passed through the wiring substrate to form the wiring pattern. It is projected on the surface provided, and one end of the connecting conductor is electrically connected to and fixed to the protruding lead terminal, and this connecting conductor is allowed to have a length and the other end is soldered and fixed to the wiring pattern. A connection structure between a wiring board and a circuit component characterized by being configured as follows. 2. The connection structure of a wiring board and a circuit component according to claim 1, wherein one end portion of the connection conductor is wound in a coil shape, and the tip portion of the lead terminal is fitted and inserted into the coiled portion, and the lead is formed. A connection structure between a wiring board and a circuit component, which is configured by soldering and fixing a part of a front end side of the coil-shaped portion to a terminal. 3. The connection structure of a wiring board and a circuit component according to claim 1 or 2, wherein the circuit component is configured to be supported with respect to the wiring substrate by a leaf spring fixed to the wiring substrate. The connection structure between the wiring board and the circuit component, which is characterized by: