JPH06268128A - Semiconductor device - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the injection amount of silicone gel and improve thermal reliability. In the semiconductor device of the present invention, by changing the shape of the stress relaxation structure of the wiring terminal 2, the injection amount of the silicone gel 6 is reduced and the stress of the wiring terminal soldering portion 8 due to thermal expansion is suppressed. [Effect] In the semiconductor device, the wiring terminal soldering portion 8
High thermal reliability can be obtained with the aim of reducing the stress applied to the.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of thermal reliability in a semiconductor device.

[0002]

2. Description of the Related Art FIG. 1 is a sectional view of a conventional semiconductor device, in which 1 is a case, 2 is a wiring terminal, 3 is an insulating plate, 4 is a cooling fin, 5 is a semiconductor element, and 6 is a silicone gel. , 7 is a hard resin, 8 is a wiring terminal soldering portion, and the case 1 is fixed to the cooling fin 4 in the peripheral portion of the cooling fin 4. In the insulating plate 3, the semiconductor element mounting surface Cu plate 9 and the bonding surface Cu plate 10 with the cooling fins
The semiconductor element mounting surface Cu plate 9 is brazed with a wiring pattern.

In addition, the wiring terminal 2 and the Cu plate 9 of the insulating plate 3,
The Cu plate 10 of the insulating plate 3 and the cooling fin 4 are brazed by soldering. The wiring terminal 2 has a shape called a C bend, which is in the shape of an alphabet C as shown in FIG. 1, and the stress applied to the wiring terminal soldering portion 8 is relieved by this C bend. When the wiring terminal soldering portion 8 is bent in the C bend direction, the tensile stress is small, and by increasing the C bend, the stress applied to the soldering portion is reduced in both tension and compression.

In such a module structure, non-uniform stress is generated in each wiring terminal in the semiconductor device due to temperature change. A crack is generated in the specific wiring terminal soldering portion 8 where the stress is concentrated, and in an extreme case, peeling occurs. The main cause is considered to be the expansion of the silicone gel 6, which has an extremely large coefficient of thermal expansion as compared with other members. The thermal expansion coefficient of the silicone gel 6 is 3 × 10 ⁻⁴ / ° C., and that of Cu and AlN is 17 × 10 ⁻⁶ / ° C., 4
It can be seen that it is much larger than × 10 ^-6 / ° C. In the present invention, attention is paid to the relationship of FIG. 2, and the structure is such that the height of the wiring terminal 2 is lowered in order to reduce the injection amount of the silicone gel 6.

[0005]

SUMMARY OF THE INVENTION In the present invention, the amount of silicone gel 6 injected is reduced to reduce the stress generated in the wiring terminal soldering portion 8 due to thermal expansion, without sacrificing other performances. In view of the above, a semiconductor device having high thermal reliability is provided.

[0006]

This is a proposal to reduce the injection amount of the silicone gel 6 by lowering the height of the wiring terminal 2 by paying attention to the relationship of FIG.

[0007]

A semiconductor device with high thermal reliability can be provided without sacrificing other performances. The package can be downsized.

[0008]

FIG. 3 shows an embodiment of the present invention. Here, the structure of the bend of the C bend is changed from the vertical direction to the plane direction. This outline drawing is shown in FIG. At this time, the tensile stress and the compressive stress are not different from those of the conventional one.

The height of the wiring terminal 2 is cut by about 50% in external dimensions and the injection amount of the silicone gel 6 can be halved as compared with the conventional case. Therefore, the amount of displacement due to heat is reduced, the stress of the soldered portion can be reduced, and high thermal reliability can be improved.

FIG. 5 shows another embodiment. This drawing shows an example of the structure. By making the stress relaxation structure of the wiring terminal 2 into an S shape, a stress relaxation structure larger than that of the C-bend shape can be obtained, and a higher thermal resistance can be obtained.

FIG. 6 shows another embodiment. This drawing shows an example of the structure. The structure is characterized in that the stress relaxation structure of the wiring terminal 2 is I-shaped, and can be manufactured more easily than 2a and 2b. Moreover, since the length of the wiring terminal is shorter than the other terminals, the wiring resistance can be reduced.

[0012]

EFFECTS OF THE INVENTION The occurrence of cracks in the soldered portions of wiring terminals due to temperature change, which is one of the factors of destruction of semiconductor devices, can be reduced by reducing the amount of silicone gel 6 injected, and the thermal fatigue reliability can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a conventional technique.

FIG. 2 is a diagram showing a relationship between the amount of silicone gel 6 and its displacement amount by a heat cycle test.

FIG. 3 is a sectional view of an embodiment of the present invention.

FIG. 4 is a three-dimensional view showing the shape of the wiring terminal 2 of the present invention.

FIG. 5 is a three-dimensional view showing the shape of the wiring terminal 2 according to another embodiment of the present invention.

FIG. 6 is a three-dimensional view showing the shape of the wiring terminal 2 according to another embodiment of the present invention.

[Explanation of symbols]

1 ... Case, 2 ... Wiring terminal, 3 ... Insulating plate, 4 ... Cooling fin, 5 ... Semiconductor element, 6 ... Silicone gel, 7 ... Hard resin, 8 ... Wiring terminal soldering part Semiconductor element mounting surface Cu
Plate, 9 ... Semiconductor element mounting surface Cu plate, 10 ... Bonding surface Cu plate with cooling fins.

Front page continued (72) Inventor Toshiki Yagihara 3-10-2 Bentencho, Hitachi City, Ibaraki Prefecture Hitachi Haramachi Electronics Industry Co., Ltd.

Claims (6)

[Claims] 1. A semiconductor device in which an insulating substrate treated with an electrode is arranged on a metal base, a semiconductor element is arranged on the insulating substrate, and the outer peripheral portion is covered with a silicone gel and a resin and enclosed by a case. Cu on insulating substrate
A semiconductor device, wherein a stress relaxation structure of a soldering portion formed on a wiring terminal brazed to a plate is provided in a plane. 2. The semiconductor device according to claim 1, wherein the stress relaxation structure has a C-shaped bend. 3. The semiconductor device according to claim 1, wherein the stress relaxation structure has an S-shaped bend. 4. The semiconductor device according to claim 1, wherein the shape of the stress relaxation structure is made linear by shifting the positions of the wiring terminal soldering portion with the Cu plate and the case bonding portion. 5. The semiconductor device according to claim 1, wherein the metal material is copper. 6. The semiconductor device according to claim 1, wherein the metal material is brass.