JP2521624Y2 - Semiconductor device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a semiconductor device, a radiation fin or a semiconductor device mounted on a printed wiring board.

[0002]

2. Description of the Related Art Conventionally, in the case of forming a semiconductor device using semiconductor chips such as diodes and transistors, for example, as shown in the sectional structural view of FIG. The connecting members 4 and 4 are sequentially placed and fixed to each other by the solder layer 5. Three
The metal plate is used as a supporting means, a spacing maintaining means, a thermal fatigue preventing means, a heat radiating means, and the like, and as a metal material, molybdenum, tungsten, copper, silver, or the like is selected and used as needed.

However, since the brazing surface of the metal plate 3, that is, the surface facing the semiconductor chip 1 side and the metal member 2 side is flat, there are the following drawbacks.

In soldering a metal plate, a flux is applied to improve the wetting property of the solder and is fixed by heating and cooling. The remainder is apt to cause voids (cavities) in the solder layer. The generation of such voids weakens the solder bond and deteriorates the reliability of the semiconductor device.

In the environment of long-term cooling / heating cycle, since the peripheral thickness of the solder layer is thin, the thermal buffering effect is small, and cracks are easily generated in the peripheral part due to the thermal fatigue phenomenon, and the life of thermal fatigue is short.

[0006]

The object of the present invention is to solve the above-mentioned disadvantages of the conventional device,
It is intended to provide a semiconductor device having a reduced occurrence rate of voids and a long thermal fatigue life. Further, the semiconductor device mounted on the heat radiation fin or the printed wiring board is also provided.

[0007]

2 is a cross-sectional structural view of an embodiment of the present invention, in which the same symbols as in FIG. 1 indicate the same parts. The metal member 2 constitutes a heat radiating fin of aluminum or copper having a recess for accommodating the metal plate and the semiconductor chip 1.

The metal plate 3 is shown in a plan view in FIG.
As shown in the side view in (b), convex curved surfaces 3a are formed on both upper and lower surfaces.

In the manufacture, the first solder chip, the metal plate 3, the second solder chip, the semiconductor chip 1, the third solder chip, and the connecting member 4 are laminated in the recess of the metal member 2 (radiation fin). By housing and heating, the first, second,
The solder layer 5 is formed by melting the third solder chip and then solidifying it.

Since the metal plate 3 has convex curved surfaces 3a formed on both upper and lower surfaces, flux or the like which causes voids during melting and solidification of the solder from the central portion of the metal plate 3 to the peripheral portion. On the other hand, it becomes easier to escape, and the occurrence of voids after solidification of the solder layer is significantly reduced.

The peripheral portions of the solder layers 5 on the upper and lower surfaces of the metal plate 3 are thicker than the central portion thereof (excluding the portion which is thinned by the spreading effect to the outer periphery when the solder layer 5 is melted). The occurrence of cracks in the solder layer, which is a thermal fatigue phenomenon under a low temperature thermal cycle environment, is reduced as compared with the conventional device of FIG.

Further, the heat dissipation effect is improved by increasing the area of the semiconductor chip 1, the metal plate 3 and the metal member 2 in this order.

In FIG. 2, a convex curved surface 4 is formed at a connection portion of the connection member 4 such as a connection piece or a header lead wire with the semiconductor chip 1.
By forming a, the same effect as 3a of the metal plate 3 can be obtained.

FIG. 4 is a sectional view of another embodiment of the present invention, in which the same reference numerals as those in FIGS. 1, 2 and 4 designate the same parts. The second metal member is a conductive layer provided on the substrate 6 of the printed wiring board. There are various types of printed wiring boards, such as ceramic boards, aluminum-based copper clad boards, glass, and epoxy copper clad laminated boards. The present invention can be applied to any printed wiring board. Further, 7 is another electronic component provided on the substrate 6, which constitutes various composite or hybrid integrated circuit devices.

The embodiment of FIG. 4 also exhibits the same operation and effect as described in the embodiment of FIG.

In the embodiment of the present invention, the shape described above,
The materials and the like can be modified, changed, added, deleted, and changed within the scope of the present invention. For example, the metal plate 3 can be selected from copper, molybdenum, tungsten, etc. according to need.

[0017]

As described above, the semiconductor device of the present invention is capable of reducing voids in the solder layer and improving the thermal fatigue performance of the solder layer, and is mounted on a radiation fin or a printed wiring board. The semiconductor device is effective as a semiconductor device, and has a great practical effect when used in various electrical devices that require high reliability such as electrical components.

[Brief description of drawings]

FIG. 1 is a sectional structural view of a conventional semiconductor device.

FIG. 2 is a sectional view showing an embodiment of the present invention.

3A and 3B are structural views of the metal plate used in FIG. 2, where FIG. 3A is a plan view and FIG. 3B is a side view.

FIG. 4 is a sectional structural view showing another embodiment of the present invention.

[Explanation of symbols]

 1 Semiconductor Chip 2 Metal Member 3 Metal Plate 3a Convex Curved Surface of Metal Plate 4 Connection Member 4a Convex Curved Surface of Connection Member 5 Solder Layer 6 Board 7 Other Electronic Components

Claims (4)

(57) [Scope of utility model registration request] 1. A semiconductor chip is fixed to one surface of a metal plate having convex and curved surfaces formed on the upper and lower surfaces, respectively, and a metal member is fixed to the other surface via a solder layer, which are a semiconductor chip, a metal plate, and a metal member. The semiconductor device is characterized in that the area is increased in the order of, and the thickness of the solder layer is larger in the peripheral portion than in the central portion of the convex curved surface. 2. The semiconductor device according to claim 1, wherein the metal member is a metal radiation fin. 3. The semiconductor device according to claim 1, wherein the metal member is a metal layer on a printed wiring board. 4. The semiconductor device according to claim 1, 2 or 3, wherein a convex curved surface of the connecting member is soldered to the surface of the semiconductor chip opposite to the surface soldered to the metal plate.