JPH0122986B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor cooling device, and more particularly to an insulating disk that can efficiently transmit insulation and loss heat of semiconductor elements and facilitate assembly work.

A conventional device of this type is shown in FIG. In the figure, 1a is a flat semiconductor element body (hereinafter referred to as the element body), 2a and 2b are terminal plates that are connected to the anode and cathode surfaces of this element body 1a to take out electricity, and these terminal plates 2a and 2b and the element body. 1a to form a flat semiconductor element 1. 3
5 is an insulating sheet that electrically insulates the flat semiconductor element 1 and the cooling block 4; 5 is an insulating seat;
1 is a pressure contact seat, 7 is a spring plate, 8 is a tightening bolt, 9 is a bolt, and 10 is a metal ball disposed between this bolt and the pressure contact seat 6.

The following operation will be explained.

Normally, when current is applied to the flat semiconductor element 1, heat is generated due to internal loss of the flat semiconductor element 1.
Since this heat loss is dissipated from the terminal plates 2a and 2b, which are the anode and cathode surfaces of the flat semiconductor element 1, the cooling block 4 is press-connected to either the two pole surfaces of the flat semiconductor element 1, or one of them to reduce the loss. Heat is exchanged to a secondary cooling medium such as air. At this time, if there is no insulating sheet 3 as shown in FIG. 1, the cooling block 4 is directly press-contacted to the flat semiconductor element 1, so it will be charged with the potential of the flat semiconductor element 1. In order to prevent deterioration or danger, they were often housed in a cubicle with a housing structure. However, in order to suppress the temperature rise inside the cubicle, it is necessary to bring in outside air.
There was a problem with inspection, etc. Recently, as shown in FIG. 1, a flat semiconductor device 1 and a cooling block 4 have been developed.
For electrical insulation, an insulating sheet 3 made of the same material as the insulating sheet disposed outside the housing cubicle is used. This insulating sheet 3 is made of an excellent material that can provide electrical insulation and efficiently transmit heat loss from the flat semiconductor element 1 to the cooling block 4, and must be extremely thin and formed into a circular or rectangular sheet shape. be.

Since the conventional semiconductor cooling device is configured as described above, an ultra-thin insulating sheet 3 is used for insulation.
must be inserted between the cooling block 4 and the flat semiconductor element 1 and pressure-welded, and surface processing and assembly work of the pressure-welding surface of the cooling block 4, such as center alignment of the flat semiconductor element 1 and the insulating sheet 3, contact thermal resistance. It is very difficult to apply conductive grease to reduce the size of the insulating sheet 3, and since the insulating sheet 3 is extremely thin, it is extremely difficult to handle it to prevent cracks.

This invention was made in order to eliminate the drawbacks of the conventional products as described above, and consists of bonding blocks of copper, aluminum, etc. to both press-contact surfaces of an insulating sheet by brazing or soldering, etc., to form an integral disk-like structure. The object of the present invention is to provide a highly reliable semiconductor cooling device that improves assembly workability and thermal conductivity by forming a semiconductor cooling device.

An embodiment of the present invention will be described below with reference to the drawings. In FIGS. 2 and 3, reference numeral 2 denotes the above-mentioned insulating sheet, which is made of, for example, ceramic. Copper 11 is fixed to one pressure contact surface of the insulating sheet 2 by brazing or soldering,
Blocks such as aluminum, 19 is insulation sheet 2
This block 19 is fixed by brazing or soldering to the other press-contact surface of the block 19. One end of this block 19 has a mounting hole 18 for attaching a snubber diode, etc., and the other end has an anode and a cathode surface of a flat semiconductor element. A bolt hole 20 for electrical extraction is provided, and it can be used as a terminal plate for a flat semiconductor device. 12a and 12b are brazed or soldered surfaces, and 13 is a hole formed in the blocks 11 and 19 for centering with the flat semiconductor element 1.

According to the above configuration, the thin insulating sheet 2
An integrated insulating disk is constructed by the blocks 11 and 19 which are fixed thereto by brazing and soldering. With this structure, it is possible to electrically insulate the flat semiconductor element 1 and the cooling block 4 and to transfer heat loss from the flat semiconductor element 1 very efficiently. In addition, insulation sheet 2
The thickness of the device is approximately 1 to 2 mm, and the pressure force between the flat semiconductor element 1 and the cooling block 4 is approximately 1000 to 2 mm.
Because it is extremely large at approximately 4000 kg, conventionally there have been drawbacks such as damage to the insulation sheet due to the adhesion of impurities such as dust to the pressure welding surface, and an increase in contact thermal resistance due to the combination of insulation sheets with impurities attached. However, since the blocks 11, 19 made of copper, aluminum, etc. are fixed and integrated with the insulating sheet 2 to form the insulating disk, this problem can be reliably solved.
Furthermore, since the holes 13 for centering are formed in the blocks 11 and 19, it is difficult to center the insulating sheet 2 during assembly work, and deviations can be avoided.
The insulating sheet 2 can be easily inserted and attached without twisting or the like. Moreover, this center alignment hole 1
3, when brazing or soldering the insulating sheet 2 and the blocks 11 and 19, it becomes an escape port for air bubbles on the contact surface, and a contact surface with good adhesion can be obtained, so that the contact thermal resistance is reduced. It is useful for producing insulating disks that are low in temperature and have good thermal conductivity.

FIG. 4 shows the present invention applied to a circuit constituting a part of a flat semiconductor device. In the figure, 1a and 1b are main thyristors through which a large current flows, and flat semiconductor elements of, for example, 1000 A class are used. 14a and 14b are the main thyristors 1
This is an auxiliary diode connected in antiparallel to a and 1b to bypass reactive current, and is a flat semiconductor element of, for example, 300A class. 15a,1
5b is a snubber resistor, 16a and 16b are snubber capacitors, and 17a and 17b are snubber diodes. And these snubber diodes 17a, 17
Since a relatively small capacitance element like b has a small loss of heat, it can be attached to a copper material of the same potential bonded to the insulating sheet 2 of the above embodiment.

As described above, according to the present invention, a block made of copper, aluminum, etc. with a hole for centering is adhered to one side of an insulating sheet, and a block made of copper, aluminum, etc., with a hole for centering is adhered to one side of the insulating sheet, and a block made of copper, aluminum, etc., which will become a terminal board for a semiconductor element is bonded to the other side of the insulating sheet. By fixing blocks with center alignment holes, etc., to form an integrated insulating disk, there is no risk of an increase in the contact thermal resistance between the insulating disk and the semiconductor element, and the thermal conductivity increases. This is a dramatic improvement, and the assembly work is extremely simple.Furthermore, the block glued to the other side of the insulating sheet can be used as a terminal board for semiconductor devices.
This has the effect of further improving heat dissipation.

[Brief explanation of drawings]

Figure 1 is a side view of a conventional semiconductor cooling device, Figure 2 is a side view of a conventional semiconductor cooling device;
The figure is a plan view of one embodiment of this invention, and FIG.
FIG. 4, which is a vertical cross-sectional view taken along the line - in the figure, is a circuit diagram in which the present invention is applied to a semiconductor circuit that constitutes a part of a general flat semiconductor device. 1... Semiconductor element (flat semiconductor element), 3...
Insulating sheet, 4...Cooling block, 11, 19...
...Blocks of copper, aluminum, etc. In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In a semiconductor cooling device in which a cooling block is placed in contact with one pole surface of a semiconductor element for cooling, a hole for center alignment is drilled, and one of the holes is made of copper or aluminum that serves as the terminal plate of the semiconductor element. A semiconductor cooling device characterized in that blocks such as the above are bonded to both sides of an insulating sheet by soldering or brazing to form an insulating disk, and this insulating disk is pressed between the semiconductor element and the cooling block. .