JPS64812B2 - - Google Patents

Abstract

PURPOSE:To prevent the generation of a crack in an insulating base body by forming the cover member of an insulating frame body disposed while surrounding a semiconductor element by a material having a thermal expansion coefficient equal to a radiator arranged to the base body on which the semiconductor element is placed. CONSTITUTION:The semiconductor element 32 is fixed onto a metallized lyaer 33a shaped to the surface of the vessel base body 31 consisting of a ceramic material, the ceramic frame body 35 is disposed while surrounding the semiconductor element 32 on the vessel base body 31, the cover 36 is fastened onto the frame body, the radiator 38 is mounted to the lower surface of the vessel base body 31, and the radiator 38 and the cover 36 are made of the same member such as copper. Accordingly, since the cover 36 also expands and contracts in the same direction even when the radiator expands and contracts when heat treatment such as fixing is executed, stress applied to the vesel base only 31 is offset, and there occurs no crack in the vessel base body 31.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor device, and more particularly to a power semiconductor device using an element housing container mainly made of ceramic material as an element housing container (package).

Conventionally, an element housing container mainly made of ceramic material (hereinafter referred to as a ceramic package) has been
For example, it has the structure shown in FIG.

In the figure, 11 is a container base made of a ceramic material such as alumina (Al ₂ O ₃ ), and 12 is a metallized layer 13a formed on the surface of the container base 11, which is fixed with a brazing material. For example, it is a semiconductor element such as a transistor. Other electrodes of the semiconductor element 12 are lead wires 14a and 14b.
It is connected to the metallized layers 13b and 13c formed on the surface of the container base 11 through. Further, 15 is a ceramic frame disposed on the container body 11 to surround the semiconductor element 12, and 16 is a ceramic frame fixed to the ceramic frame 15 by a metallized layer formed on the top surface of the ceramic frame 15. The cap is made of ceramic or Kovar. Further, 17a and 17b are external connection terminals made of Kovar, for example, and connected to the metallized layers 13b and 13c on the outside of the ceramic frame 15.

In such a semiconductor device, when the semiconductor element 12 handles large electric power, the second
As shown in the figure, a copper heat sink (heat shrink) is attached to the lower surface of the container base 11 that supports the semiconductor device 12 (the surface opposite to the surface on which the semiconductor device 12 is fixed).
21 is fixed with a brazing material such as gold tin or solder.

However, in such a structure, cracks may occur in the ceramic container base 11 due to expansion and contraction of the heat radiator 21 during fixation or subsequent heat treatment (part A in FIG. 2). , resulting in a decrease in manufacturing yield and reliability of the semiconductor device.

The present invention aims to eliminate such drawbacks of conventional semiconductor devices and provide a semiconductor device that can achieve higher manufacturing yield and reliability.

Therefore, according to the present invention, there is provided a semiconductor element mounted and fixed on one main surface of an insulating substrate, an insulating frame disposed surrounding the semiconductor element on the main surface, and the insulating frame In the semiconductor device, the lid member is fixed to the heat sink, a heat sink disposed on the other main surface of the insulator base, and an external connection terminal led out from the semiconductor element. A semiconductor device is provided that is made of materials having similar coefficients of thermal expansion.

The present invention will be explained in detail below using examples.

FIG. 3 shows a semiconductor device according to the invention.

In the figure, 31 is a container base made of ceramic material such as alumina (Al ₂ O ₃ ), and 32 is a metallized layer 33a formed on the surface of the container base 31, which is fixed with a brazing material. For example, it is a semiconductor element such as a transistor. The other electrodes of the semiconductor element 32 are lead wires 34a and 34b.
It is connected to the metallized layers 33b and 33c formed on the surface of the container base 31 via. Further, 15 is a ceramic frame disposed on the container body 31 to surround the semiconductor element 32, and 36 is a ceramic frame fixed to the ceramic frame 35 by a metallized layer formed on the top surface of the ceramic frame 35. Cap
It is. Further, 37a and 37b are the metallized layers 33b and 3 on the outside of the ceramic frame 35.
3c is an external connection terminal made of Kovar, for example. Furthermore, 38 is a heat sink made of copper and fixed to the lower surface of the container base 31 with a brazing material such as gold-tin or solder. The heat sink 38 is attached after the mounting and fixing of the semiconductor element 32 to the container base 31, the connection of the lead wires 34, the fixing of the lead wires 36, etc. are completed.

In the present invention, the member constituting the lid 36 is made of the same material as the heat sink 38;
That is, copper is used in this embodiment.

According to such a configuration, even if the heat radiator 38 expands or contracts due to the heat treatment when fixing the heat radiator 38 to the container base 31 or the subsequent heat treatment, the lid 3
6 also expand and contract in the same direction, the stress applied to the container base 31 is canceled out, and no cracks are caused to the container base 31.

Incidentally, since the volume of the lid 36 itself is small, the stress applied to the ceramic frame 35 and the container base 31 when the lid 36 is fixed to the ceramic frame 35 is small, and no cracks occur. Therefore, the lid 36 and the heat sink 37 may be fixed at the same time at a temperature of about 300 [°C], or after the cover 36 is fixed at a temperature of about 300 [°C], the heat sink 38 is fixed at a temperature of about 240 [°C]. ] It is also possible to use a method of fixing at a temperature of about

As described above, according to the present invention, the lower surface of the ceramic container base (the surface opposite to the surface on which the semiconductor element is fixed) is ) By using the same material as the heat sink disposed in the heat sink, no cracks will occur in the ceramic container base during fixation of the heat sink or during subsequent heat treatment, and the manufacturing yield and reliability of semiconductor devices can be improved. .

Note that the material constituting the lid member does not have to be the same as the material constituting the heat sink, but any material can be used as long as it has substantially the same coefficient of thermal expansion. For example, when copper is used as the material for the heat sink, the material for the lid member is
Aluminum, silver, etc. can be used.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing the structure of a conventional semiconductor device, and FIG. 3 is a cross-sectional view showing the structure of a semiconductor device according to the present invention. In the figure, 11, 31... Ceramic container base, 12, 32... Semiconductor element, 15, 35...
Ceramic frame body, 16, 36...lid (cap),
21, 38... Heat sink.

Claims (1)

[Claims] 1. A semiconductor element mounted and fixed on one main surface of an insulating substrate, an insulating frame disposed surrounding the semiconductor element on the main surface, a lid member fixed to the insulating frame, and the In a semiconductor device comprising a heat sink disposed on the other main surface of an insulating substrate and an external connection terminal led out from the semiconductor element, the lid member is made of a material having a coefficient of thermal expansion equivalent to that of the heat sink. A semiconductor device comprising: