JPS63308944A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent production of cracks in a ceramic substrate, by providing a groove around a chip carrying position of a heat dissipating bottom plate. CONSTITUTION:A heat dissipating bottom plate 4 is soldered, with a soldering material 3, on a metallized layer 2 provided on one face of a ceramic substrate 1 having a through hole at the center thereof, and a semiconductor chip 5 is attached to the part of the bottom plate 4 corresponding to the through hole of the substrate, by means of Au/Si eutectic crystals. A groove 11 is formed around this chip carrying part of the heat dissipating bottom plate 4, so that any stress caused by difference in thermal properties between the ceramic substrate 1 and the bottom plate 4 is concentrated to the groove 11 and, thereby, stress in the substrate 1 can be alleviated. Thus, it is possible to prevent cracks which otherwise would be produced along the periphery of the heat dissipating bottom plate.

Description

[Detailed Description of the Invention] [4 Already Required] A semiconductor device in which a chip is mounted on a heat dissipation bottom plate brazed to a ceramic substrate, in which a groove is provided around the chip mounting position of the heat dissipation bottom plate. It is possible to prevent the occurrence of cranks in the ceramic substrate due to stress due to the difference in thermal characteristics between the ceramic substrate and the heat dissipation bottom plate.

[Industrial Field of Application] The present invention relates to a semiconductor device, and more specifically, to a semiconductor device that prevents cranking from occurring in a ceramic substrate due to a difference in coefficient of thermal expansion with a heat dissipating bottom plate.

[Conventional technology]

FIG. 3 is a diagram showing an example of a conventional semiconductor device. This is a heat dissipation bottom plate 4 which is soldered using a brazing material 3 onto the metallization 2 applied to one side of a ceramic substrate l having a through hole in the center. A chip is attached using /Si eutectic, wire bonding is performed between the electrode and the lead wire from the terminal 6 of the substrate 1 using a thin wire 7, and the fin 8 for heat dissipation is placed on the bottom plate 4.
are glued together with resin 9. The materials shown in Table 1 are used for each component of this semiconductor device, and the thermal characteristics thereof are shown in the same table.

Table 1 [Problems to be Solved by the Invention] In the conventional semiconductor device described above, due to the difference in thermal characteristics between the ceramic substrate 1, brazing material 3, and heat dissipation bottom plate 4, the ceramic substrate 1, there was a problem in that cracks 10 occurred along the outer periphery of the heat dissipation bottom plate 4 as shown in FIG. 4, and similar cracks also occurred during the thermal shock test.

The present invention was created in view of these points.
The object of the present invention is to provide a semiconductor device that prevents cranks from occurring on a ceramic substrate.

[Means for solving the problem] Therefore, in the present invention, as illustrated in FIG.
A ceramic substrate 1 having a hole passing through the center and having metallization 2 applied around the hole; a heat dissipation bottom plate 4 soldered to the metallized surface of the substrate 1 using a brazing material 3; A semiconductor device comprising a semiconductor chip 5 fixed to a heat dissipating base plate 4 is characterized in that a groove 11 is provided around the chip mounting position of the heat dissipating base plate 4.

[Function] By providing the groove 11 around the chip mounting position of the heat dissipation bottom plate 4, stress due to the difference in thermal characteristics between the ceramic substrate 1 and the heat dissipation bottom plate 4 can be alleviated, and the ceramic substrate It becomes possible to prevent cracks from occurring.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention, in which a is a cross-sectional view;
b is a diagram showing the heat dissipation bottom plate viewed from the Z-top direction in diagram a;

As shown in the figure, in this embodiment, a heat dissipating bottom plate 4 is brazed with a brazing material 3 onto a metallization 2 formed on one side of a ceramic substrate 1 having a through hole in the center. A semiconductor chip 5 is attached to the part using Au/Si eutectic, wire bonding is performed between the electrode and the lead wire from the terminal 6 of the substrate 1 using a thin wire 7, and a heat dissipating fin 8 is attached to the heat dissipating bottom plate 4 using resin 9. This is the same as the conventional example explained in FIG. 3, and the key point of this embodiment is that a groove 11 is provided around the chip mounting position of the heat dissipation bottom plate 4.

In this embodiment configured as described above, the stress generated in the ceramic substrate 1 can be alleviated by concentrating the stress generated due to the difference in thermal characteristics between the ceramic substrate 1 and the heat dissipation bottom plate 4 in the groove 10. This makes it possible to prevent cracks from occurring along the outer periphery of the heat dissipation bottom plate.

FIG. 2 is a diagram showing another embodiment of the present invention, and the same parts as in FIG. 1 are designated by the same reference numerals.

This embodiment differs from the previous embodiment in that 411 is provided on both sides of the heat dissipation bottom plate 4, and the effect is the same as that of the previous embodiment.

[Effects of the Invention] As described above, according to the present invention, with an extremely simple configuration, it is possible to prevent the occurrence of cracks in the ceramic substrate due to the difference in thermal characteristics with the heat dissipation bottom plate, and it is practical. is extremely useful.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an embodiment of the present invention, Fig. 2 is a diagram showing another embodiment of the invention, Fig. 3 is a sectional view showing a conventional semiconductor device with a bottom plate for heat dissipation, and Fig. 4 is a conventional diagram. FIG. 3 is a diagram for explaining problems of the semiconductor device of FIG. In FIGS. 1 and 2, 1 is a ceramic substrate, 2 is metallized, 3 is a brazing material, 4 is a heat dissipation bottom plate, 5 is a semiconductor chip, 8 is a heat dissipation fin, and 11 is a groove. patent application agent

Claims (1)

[Claims] 1. A ceramic substrate (1) with a hole passing through the center and metallized (2) around the hole, and a brazing material (2) on the metallized surface of the substrate (1). 3) A semiconductor device comprising a heat dissipating base plate (4) soldered using a heat dissipating base plate (4) and a semiconductor chip (5) fixed to the heat dissipating base plate (4), wherein the chip is mounted on the heat dissipating base plate (4). A groove (1
A semiconductor device characterized by having 1).