JPS6330779B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION 1. The present invention relates to a semiconductor device, and in particular to a semiconductor device that enables good connection between a flat semiconductor element and an external lead electrode.

An example of a conventional semiconductor device of this type is shown in FIG. In FIG. 1, 1 is a diode element, 2 is a cathode electrode body made of a copper pillar material attached to the cathode electrode of the diode element 1, and 3 is a copper pillar material attached to the anode electrode of the diode element 1. An anode electrode body 4 is an insulating cylinder made of ceramic provided around the diode element 1, cathode electrode body 2, and anode electrode body 3, and 5 is an insulating cylinder whose outer peripheral portion is attached to one end surface of the insulating cylinder 4. , a cathode flange whose inner periphery is made of a flexible copper thin plate attached to the cathode electrode body 2; 6 a first welding ring made of an iron alloy plate attached to the other end face of the insulating cylinder 4; , 7 is a second welding ring made of an iron alloy plate whose inner circumference is attached to the anode electrode body 3 and whose outer circumference is attached to the first welding ring 6 by arc or electric resistance welding. Above 1~
7 constitutes a flat semiconductor element 10. 2
Reference numerals 1 and 22 designate a cathode externally drawn electrode and an anode externally drawn electrode made of a copper pillar material, which are in pressure contact with the cathode electrode body 2 and anode electrode body 3 of the flat semiconductor element 10 and draw out electric heat. Although not shown, the cathode and anode externally drawn electrodes 21 and 22 are pressurized with a pressure P from the outside by a pressurizing mechanism. As a result, the diode element 1 of the flat semiconductor element 10 is brought into pressure contact with the anode electrode body 2 and the cathode electrode body 3.

By the way, in such a semiconductor device,
As the capacity of the device increases, the size of its exterior also increases, causing the following problems.

When the insulating cylindrical body 4 of the flat semiconductor element 10 vibrates, the cathode flange 5 supporting it vibrates when operating with constant irregular and intense vibrations, such as in a vehicle.
Alternatively, the second welding ring 7 may fail due to fatigue, the airtightness of the flat semiconductor element 10 may be broken, the electrical characteristics may deteriorate, and the function of the semiconductor device may stop.

When the electrical characteristics of the diode element 1 deteriorate while operating at a large current, a short circuit occurs in the degraded part, and a subsequent large current flows intensively, causing the material constituting the diode element 1 to melt and vaporize. , cathode flange 5 of flat semiconductor element 10
Alternatively, the high-temperature arc contacts the second welding ring 7, fuses it, and blows it out to the outside, resulting in loss of external equipment.

This invention was made in order to improve the above-mentioned problems, and a protective ring whose core material is made of metal and whose covering material is made of an insulating material is sandwiched between the flat semiconductor element and two external lead-out electrodes. This is intended to improve the vibration resistance and explosion-proof effect of the equipment. This invention will be explained in detail below.

FIG. 2 shows an embodiment of the present invention, FIG. 2a is a sectional view showing the configuration of a protective ring, and FIG. 2b is a configuration of a semiconductor device with the protective ring of FIG. 2a attached. FIG.

In Fig. 2a, 31 is a cylindrical metal ring made of a thin stainless steel plate with a thickness of 0.3 mm and has a zigzag cross section, and 32 is made of fluorine rubber with the metal ring 31 embedded in the center by molding. A metal ring 31 and a covering material 32 constitute an elastic cylindrical protective ring 30. The diameters of the peripheral edges of the cathode and anode externally drawn electrodes 21 and 22 in FIG. Although a gap H is formed, the height h of the protection ring 30 is made larger than this gap H (h>H).
The metal ring 31 is made of a stainless steel spring plate having a relatively large elasticity, and is completely covered with the covering material 3. As shown in FIG. 2b, the protective ring 30 configured in this manner is connected to the flat semiconductor element 10, the cathode and the anode externally drawn electrodes 21 and 2.
It is elastically deformed and held in each gap H between the two. The protective ring 30 is installed by arranging the protective ring 30 around the outer periphery of the anode external extraction electrode 22, and
Next, the flat semiconductor element 10 is placed at the center of the anode external lead electrode 22. Furthermore, a protective ring 30 is disposed around the outer periphery of the flat semiconductor element 10, and the cathode externally drawn electrode 21 is placed so as to be located at the center of the flat semiconductor element 10. Thereafter, although not shown, a pressure P is applied from the outside to the cathode and anode external extraction electrodes 21 and 22 using a pressurizing device, so that the flat semiconductor element 10 and the cathode and anode external extraction electrodes 21 and 22 are pressed into contact with each other. .
At the same time, the protective ring 30 is attached to the flat semiconductor element 1.
0, cathode, anode external extraction electrodes 21, 22
is elastically deformed at the outer periphery of the flat semiconductor element 1.
0, cathode, anode external extraction electrodes 21, 22
Eliminates the gap at the contact part with the flat semiconductor element 10.
The outer periphery is kept airtight.

Therefore, in such a semiconductor device, severe vibrations applied to the flat semiconductor element 10 can be absorbed and fixed. Moreover, the flat semiconductor element 10
Even if a large current flows through the coating material 32 and metal pieces eject, the coating material 32
and the metal ring 31 to improve the explosion-proof effect.

Note that the covering material 32 is desirably made of a material that can be molded and has arc resistance, corrosion resistance, water resistance, and heat resistance.

As explained above, in this invention, the protective ring is pressurized and held on the outer periphery between the flat semiconductor element, the cathode external extraction electrode, and the anode external extraction electrode, so that even when operating under severe vibration, a relatively large elastic force can be maintained. Since the insulating cylinder of the flat semiconductor element is held by the protective ring, the cathode flange and the second welding ring will not break due to fatigue. Further, even if the diode element is destroyed and a high temperature arc and molten metal pieces are ejected from the flat semiconductor element due to a large short-circuit current, the protection ring completely blocks the occurrence of high-temperature arc and molten metal pieces. Furthermore, the contact parts between the device's flat semiconductor element and the cathode and anode external electrodes are not exposed and the surface is flat with no recesses, reducing the adhesion of dust, moisture, etc. to the metal parts and ensuring long-lasting electrical characteristics. This not only saves time but also simplifies maintenance and inspection of the device.

As described above, according to the present invention, the vibration resistance of the flat semiconductor element can be greatly improved by the function of the protective ring composed of the core material made of metal and the covering material made of insulator, and it is also possible to significantly improve the vibration resistance of the flat semiconductor element, and also prevent the high temperature arc and melting caused by element destruction. It has many advantages, such as having an explosion-proof effect of blocking the ejection of metal pieces, and also simplifying maintenance and inspection of the device.

In addition, since the protective ring of the present invention has a bellows cylindrical metal plate as the core material, the elasticity in the same direction as the direction in which each externally drawn electrode presses the anode and cathode electrodes will be impaired by providing the core material. Moreover, even if molten metal pieces break through the covering material such as rubber of the protective ring when the element breaks, they are caught by the core material and are prevented from ejecting outward.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional semiconductor device, and FIGS. 2a and 2b show an embodiment of the present invention.
Figure a is a cross-sectional view of the protective ring, Figure 2b is Figure 2a
FIG. 3 is a longitudinal cross-sectional view of a semiconductor device in which a protective ring of FIG. In the figure, 1 is a diode element, 2 is a cathode electrode body, 3 is an anode electrode body, 4 is an insulating cylinder, 5 is a cathode flange, 6 is a first welding ring, 7 is a second welding ring, and 10 is a flat type. A semiconductor element, 21 is a cathode external extraction electrode, 22 is an anode external extraction electrode, 30 is a protective ring, 31 is a metal ring, 3
2 is a covering material. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1 External extraction electrodes are connected to both sides of a flat semiconductor element via a cathode electrode body and an anode electrode body, and the periphery of the flat semiconductor element between the cathode electrode body and anode electrode body is sealed with an insulating cylinder. In the semiconductor device, the peripheral edge of each of the external lead electrodes facing the insulating cylindrical body is narrowed in diameter to form a stepped part, and a gap is formed between the insulating cylindrical body and the peripheral edge of each of the external lead electrodes. At the same time, between the edge cylindrical body and each of the external lead-out electrodes in this space, there is provided an elastic material made of a core made of a metal plate in the shape of a bellows cylinder and a covering material made of an elastic insulator. 1. A semiconductor device characterized in that a cylindrical protection ring is held under pressure.