JP2559101B2 - Temporary fixing structure for semiconductor devices - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temporary fixing structure for temporarily fixing a semiconductor element to a wiring board before brazing.

[0002]

2. Description of the Related Art A conventional semiconductor device 1 will be described with reference to FIG. The semiconductor element 1 is composed of a main body 3 having a fixing screw hole 2 in the upper portion, and three external terminals S, C, S protruding from the lower end of the main body 3. Of the external terminals S, C, S of the semiconductor element 1, the central external terminal C is linear,
The external terminals S, S on both sides are bent like a crank. On the other hand, the wiring board 4 has external terminals S, C, S of the semiconductor device 1
The external terminal mounting holes 5, 5 and 5 are formed at the points corresponding to the vertices of the triangle.

[0003]

Usually, the semiconductor element 1 is fixed to the heat sink standing on the wiring board 4 by inserting screws into the screw holes 2 of the main body 3 to attach the external terminal mounting holes 5, 5. The external terminals S, C, S passed through 5, 5 are brazed from the back side of the wiring board 4. When the semiconductor element 1 is fixed to the heat sink in this way, the semiconductor element 1 is firmly stable even before brazing, so that the brazing operation can be easily performed. However, depending on the circuit, the semiconductor device 1
May be installed independently without being fixed to the heat sink. In this case, even if the external terminals S, C, and S are inserted into the external terminal mounting holes 5, 5, and 5, if they are pulled upward or the wiring board 4 is turned upside down before brazing, the external terminals S, C, and S will easily come off, and a slight vibration or Even if it receives a slight external force, it will tilt. Therefore, the main body portion 3 must be brazed while being supported by fingers one by one, and there is a problem that workability is extremely poor.

The present invention has been made in view of the above, and an object thereof is to first improve the efficiency of brazing work by providing a semiconductor element with a self-supporting function, and secondly to automate the brazing work. Is to

[0005]

In order to achieve the above object, the present invention provides a wiring board having a semiconductor element having three external terminals projecting from a main body and three external terminal mounting holes. There is provided a temporary fixing structure for a semiconductor element to be held by the method, wherein the temporary fixing structure for a semiconductor element is provided with the following requirements (a) to (e). (A) The three external terminal mounting holes are positioned so that the straight line connecting them draws a triangle. (B) Each external terminal is formed with a stopper deforming part in the middle of its length. (C) The bending point of the stopper deforming portion is set to be substantially at the same position as the three external terminal mounting holes. (D) The three external terminals are a set of two on both sides, and the two and the central one are in a side view substantially "C" shape or an inverted "" shape at a portion below the stopper deforming portion. Incline so that it becomes a "H" shape. (E) Each external terminal is elastically deformed and fitted into the external terminal mounting hole, and when it is stopped by the stopper deforming portion, the inner surface of the external terminal mounting hole is pressed by its own elastic restoring force.

[0006] In addition, the lower end of the external terminal has a ""
It is also possible to form an insertion guide portion that bends in a V shape and dimension the tip of the insertion guide portion in accordance with the position of the external terminal mounting hole.

[0007]

[Function] When each external terminal is elastically deformed and is inserted into the external terminal mounting hole, the elastic deformation force of the external terminal fits into the external terminal mounting hole and presses the inner surface when the stopper stops deforming. To do. This force makes it difficult for the external terminal to come out of the external terminal mounting hole, and the three external terminals stand upright. Therefore, since it is not necessary to support the semiconductor element with fingers, the brazing work is facilitated.

If the insertion guide portion is formed at the lower end of the external terminal, the positioning of the external terminal and the mounting hole for the external terminal becomes very easy, and the workability is further improved, and the semiconductor element is also provided. The brazing work can be automated.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a side view of the semiconductor element, and FIG. 2 is FIG.
3 is a partial cross-sectional view for explaining the temporary fixing step.

The semiconductor element 1 has a screw hole 2 for fixing on the top.
(See FIG. 6) and a main body portion 3 and three external terminals S, C, S protruding from the lower end of the main body portion 3. Of the external terminals S, C, S of the semiconductor element 1, the external terminals S, S on both sides have the same shape, and the external terminal C in the center has a shape symmetrical with that.

Thus, the central external terminal C has a curved portion a for absorbing an external force, which is curved in an S shape, at the base end position near the main body portion 3, and the end point of the curved portion a is sharply bent. The stopper deforming portion b is formed. This S-shaped bent portion a is designed so that the lower curve is inward so as not to touch the wiring pattern of the wiring board 4. Incidentally, if the S-shape of the bent portion a is set in the opposite direction, that is, the lower curve is set outward, the external terminal C comes into contact with the wiring pattern of the wiring board 4, which is a cause of trouble, which is not preferable.

Further, the deformed portion b for the stopper of the external terminal C
Below that, an inclined straight line portion d that inclines outward and an insertion guide portion e that changes its direction inward from the inclined straight line portion d and bends in a V shape are continuous.

On the other hand, the external terminals S, S on both sides have a line-symmetrical shape with the external terminal C at the center as described above, and have the opposite direction S.
A bent portion a having a character shape, a stopper deforming portion b at the end of the bent portion a, an inclined straight portion d, and an insertion guide portion e are provided. The external terminals S, S on both sides and the central external terminal C have an inclined straight line portion d below the stopper deforming portion b,
It is shaped like a letter “C” when viewed from the side.

The wiring board 4 to which the semiconductor element 1 is attached has a mounting hole 5 for external terminals through which the external terminals S, C, S pass.
5, 5 are drilled. The external terminal mounting holes 5, 5,
As shown in FIG. 2, 5 are arranged in a manner that the straight lines connecting them draw a triangle, and the deformed portions b, b, b for stoppers of the external terminals S, C, S and the insertion guide portions e, e, e. It is set to be almost the same as the interval at the bottom of.

Next, steps for brazing the semiconductor element 1 will be described. First, as shown in FIG. 3A, the external terminals S, C, S of the semiconductor element 1 are aligned with the external terminal mounting holes 5, 5, 5 of the wiring board 4 and are lowered straight. At the lower ends of the external terminals S, C, S, insertion guide parts e,
There are e and e, and their tips are mounting holes for external terminals 5, 5, 5
, The external terminals S, C, S easily enter the external terminal mounting holes 5, 5, 5. Then, the external terminals S, C,
When S is further lowered, the insertion guide portion e is elastically deformed, and the inclined straight line portion d of the external terminals S, C, S is also separated from the external terminal mounting holes 5, 5, 5 as shown in FIG. 3B. It elastically deforms to a state close to vertical according to.

Next, when the bending point of the insertion guide portion e passes through the external terminal mounting hole 5, the elastic restoring force of the external terminals S, C, S expands the original "C" shape. As it tries to return, the "elastic restoring force" plus the "insertion pressure by the finger" causes the external terminals S, C, S to suddenly fall to the position where they are restricted by the stopper deforming portion b. When the finger is released here, the elastic restoring force of the external terminals S, C, S causes the side surface of the inclined straight line portion d to press the upper and lower edges of the external terminal mounting hole 5 to stretch it, as shown in FIG. , It becomes a resistance and cannot come out.

In this state, even if the semiconductor element 1 is pulled upward or the wiring board 4 is turned upside down, the semiconductor element 1 does not come off, and if the body portion 3 of the semiconductor element 1 is laterally acted, the semiconductor element 1 is inclined. Even if it does, it will automatically return to its original stable state due to the urging force of the external terminals S, C, S and stand upright. The semiconductor element 1 temporarily fixed in this way is brazed from the back side of the wiring board 4 and is completely connected to the wiring board 4.

As shown in FIG. 1, the external terminals S,
The inclined straight line portion d of C and S is projected to the back side of the wiring board 4 for a long time, but because of this play, the external terminals S, C and S do not come off even if the semiconductor element 1 is largely inclined. I'll be back. However, even if the play portion is short, it is sufficient for the purpose of the present invention.

Further, as in the above embodiment, the external terminals S,
By forming a bent portion a in C and S between the body portion 3 and the stopper deformation portion b, the semiconductor element 1
It also has the effect of being less likely to be damaged even when vibration or an unexpected external force (including an external force due to thermal stress) is applied.

The present invention has been described with reference to the embodiments.
Of course, the present invention is not limited to the above embodiment. For example, in the embodiment, the inclined straight line portions d of the external terminals S, C, and S are opened outward and expanded in the shape of "C" in side view, but the inclined straight line portions d are inclined inward. It may be closed in an inverted “C” shape in a side view. In this case, the direction of the insertion guide portion e is reversed, and the external terminals S, C, S hold the wiring board 4 in a state of being fitted in the external terminal mounting holes 5, 5, 5.

Further, the embodiment has been shown to be preferable when the semiconductor element 1 is installed completely independently.
As shown in FIG. 7, the external terminals S, C, S may be eccentric to the front side, so that the external terminals S, C, S can be adapted to both the heat sink 6 and independent installation. FIG.
As is apparent from the external terminal S, the curved portion a for absorbing external force does not have to be S-shaped, and as is apparent from the external terminal C in the figure, it may not be provided at all.

Further, in the embodiment, the insertion guide portion e is formed on all the external terminals S, C, S, but the insertion guide portion e is formed.
May be provided at any of the external terminals S, C, S, or may not be provided at all external terminals S, C, S. Of course, in such a case, workability may be deteriorated, but it is sufficient to solve the problems of the conventional technology.

[0023]

As described above, according to the temporary fixing structure for a semiconductor device of the present invention, when the external terminals are elastically deformed, the external terminals are inserted into the external terminal mounting holes and the elastic deformation of the stopper prevents the external elasticity of the self-elasticity. Since it is configured to fit inside the external terminal mounting hole and press the inner surface by the restoring force, it is difficult for the external terminal to come out of the external terminal mounting hole and to stand up straight by itself. Therefore, the semiconductor element can be temporarily fixed to the extent that it is not necessary to support it with fingers, so that the brazing work becomes very easy and the workability is dramatically improved.

Further, if the insertion guide portion is formed at the lower end of the external terminal, the positioning of the external terminal and the mounting hole for the external terminal can be simplified, and the workability is further improved. Since it can be temporarily fixed by simply lowering it toward the base, it has the excellent effect of enabling automation of brazing work.

[Brief description of drawings]

FIG. 1 is a side view of a semiconductor device.

FIG. 2 is a sectional view taken along line XX of FIG.

3A and 3B are partial cross-sectional views illustrating a temporary fixing process.

FIG. 4 is a side view of a semiconductor device for explaining another embodiment.

FIG. 5 is a side view of a semiconductor device for explaining another embodiment.

FIG. 6 is a perspective view showing a conventional semiconductor element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Semiconductor element 3 ... Main body part 4 ... Wiring board 5, 5, 5 ... External terminal mounting hole S, C, S ... External terminal b ... Stopper deformation part e ... Insertion guide part

Claims (2)

(57) [Claims] 1. A temporary fixing structure for a semiconductor element, comprising: a semiconductor element formed by projecting three external terminals from a main body on a wiring board having three mounting holes for external terminals; A temporary fixing structure for a semiconductor device, characterized by comprising the requirements (a) to (e). (A) The three external terminal mounting holes are positioned so that the straight line connecting them draws a triangle. (B) Each external terminal is formed with a stopper deforming part in the middle of its length. (C) The bending point of the stopper deforming portion is set to be substantially at the same position as the three external terminal mounting holes. (D) The three external terminals are a set of two on both sides, and the two and the central one are in a side view substantially "C" shape or an inverted "" shape at a portion below the stopper deforming portion. Incline so that it becomes a "H" shape. (E) Each external terminal is elastically deformed and fitted into the external terminal mounting hole, and when it is stopped by the stopper deforming portion, the inner surface of the external terminal mounting hole is pressed by its own elastic restoring force. 2. An insertion guide portion that bends in a substantially V shape is formed at the lower end of the external terminal, and the tip of the insertion guide portion is dimensioned according to the position of the external terminal mounting hole. The temporary fixing structure for a semiconductor element according to claim 1, wherein