JPH0469818B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a flat base type semiconductor device,
In particular, it relates to the exterior structure of a flat base diode for a burner.

[Conventional technology]

The general structure of a conventional diode is shown in FIG. In the figure, 11 is a stud formed to accommodate a diode element 2 as a semiconductor element, and a hexagonal part _11-2 made of copper has a screw _11-3 made of copper and ^a case _11-1 made of iron. Connected and configured. And this hexagonal part 11 _-2 and screw 1
1 _-3 has an integrated structure, and the case 11 _-1 is fixed to the hexagonal part 11 _-2 by brazing, and the stud 11
becomes. Further, 13 is a cathode rod made of copper and has a collar portion 13a at the lower part, 14 is an insulating ring made of ceramic, and 15 is a disc spring made of steel.
Furthermore, 16 is a cap, which is constructed by connecting an insulator 16 _-1 made of ceramic to a relay tube 16 _-2 made of copper and a flange 16 _-3 made of iron. At this time, the insulator 16 _-1 , the relay tube 16 _-2 and the flange 16 _-3 are each brazed and fixed to the insulator 16 _-1 to form the cap 16. Also, 17
is a lead made of stranded copper wire.

The assembly of the diode configured in this way is
First, the diode element 2 is inserted into the stud 11. Next, the insulating ring 14 and disc spring 15 are inserted into the cathode rod 13 and attached to the upper surface of the collar 13a, and the lower surface of the collar 13a is placed on the diode element 2. At this time, the cathode rod 13 is centered by the case _11-1 of the stud 11 and the insulating ring 14. Further, the disc spring 15 is positioned by the inner wall of the case 11 _-1 of the stud 11.

Next, the case 1 of the stud 11 is compressed from above using a pressure device (not shown).
By narrowing the upper part of _1-1 toward the center, the collar 13a of the cathode bar 13, the diode element 2, and the hexagonal part _11-2 of the stud 11 are pressed together by the disc spring 15 and integrated.

Next, the stud 11 integrated in this way
and cover the cathode rod 13 with the cap 16.
flange _16-3 and stud 11 case _11-2
and the welding protrusion 11a are fixed by welding. Thereby, the diode element 2 is sealed by the stud 11 and the cap 16.

Finally, the lead 17 is inserted into the relay tube _16-2 of the cap 16, and the upper and lower parts of the relay tube _16-2 are mechanically compressed, and the relay tube _16-2 , the lead 17, and the relay tube 16-2 are compressed mechanically _{. 2} and the cathode rod 13 are electrically connected by crimping.

[Problem that the invention seeks to solve]

However, when such a conventional stud-type diode is used, for example, as a snubber of a gate turn-off thyristor, 1) the cathode bar 13 has a long length and a small diameter, resulting in a large inductance. Also, 2) cathode rod 13
If there is a ferrous material such as a disc spring 15 around the
During energization, the disc spring 15 increases the inductance. Problems such as this occur. As a result, the spike voltage at turn-off increases,
This had the disadvantage of reducing the controllable current of the gate turn-off thyristor.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a flat base type semiconductor device in which the current path is enlarged and shortened to reduce the inductance of the current path portion. .

[Means for solving problems]

The flat base type semiconductor device according to the present invention includes:
A base serving as a lower electrode that accommodates a semiconductor element and is formed to surround the peripheral side of the semiconductor element, and an electrode block serving as an upper electrode placed on the upper surface of the semiconductor element housed in the base to constitute a sealed container thereof. The semiconductor element inserted between the electrode block and the base is brought into pressure contact with a pressure member made of a non-magnetic material inserted into the electrode block, so that the base, the electrode The semiconductor element is hermetically sealed by sealing both ends of each block with a sealing cap formed to surround the peripheral surfaces between the blocks.

[Effect]

In the flat base type semiconductor device of the present invention, the shape of the upper electrode constituting the sealed container is made into a block shape, and the material of the pressurizing member around it is made of a non-magnetic material such as stainless steel. Inductance can be reduced.

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a sectional view showing the structure of a flat base diode according to an embodiment of the present invention. 1st
In the figure, 1 is a diode element 2 similar to the conventional one.
This base 1 is made up of a disc-shaped block _1-1 made of copper and a cylindrical case _1-2 made of iron. The case 1-2 is fixed by brazing, and a welding ring _1-3 is formed on the outer peripheral surface of the case _1-2 . Reference numeral 3 designates a cathode block as an upper electrode which is placed on the diode element 2 housed in the base 1 and forms a part of the sealed container.This cathode block 3 is made of copper and has a collar portion 3 _{- 1}
is formed, and a welding ring _3-2 made of iron is fixed to the upper part by brazing. The base 1 and the cathode block 3 each have a screw hole drilled in the center to provide a mounting thread 1.
a, 3a are provided, and mounting screw portions 1b, 3b are provided on the outside by thread processing, respectively.

Further, numeral 4 is an insulating ring made of ceramic that can be inserted into the collar _3-1 of the cathode block 3, and 5 is made of stainless steel SUS304 that can also be inserted into the cathode block 3. A disc spring 6 as a pressure member includes a ring-shaped insulator 6 _-1 made of ceramic, and flanges 6 _-2 and 6 _- made of iron brazed to the upper and lower parts of the insulator 6 _-1 , respectively. ₃ , and this cap 6 is a welding ring 1 of the base 1.
_-3 and the weld ring 3 _-2 of the cathode block 3 to seal the inside thereof.

Therefore, when assembling the diode configured in the above embodiment, first, the diode element 2 is inserted into the base 1, the insulating ring 4 and the disc spring 5 are inserted into the cathode block 3, and the diode element 2 is placed on the diode element 2. . Next, while compressing the disc spring 5 from above using a pressure device (not shown), the upper part of the case 1 _{- 2} of the base 1 is squeezed toward the center. This is exactly the same as the conventional assembly method. Next, the cap 6 is placed over the cathode block 3 and the base 1, and the flange _6-3 of the cap 6 and the weld ring _3-2 of the cathode block 3 are connected.
The flange _6-3 of the cap 6 and the welding ring _1-3 of the case _1-2 are brought into close contact with each other and fixed by welding. Thereby, the diode element 2 is sealed by the base 1, cap 6, and cathode block 3.

The flat base diode manufactured in this manner is significantly smaller in height than the conventional example shown in FIG. For example, when comparing 400A class diodes, the height from the bottom of diode element 2 to the top of cap 6 is conventionally
The one with a diameter of 80 mm is 25 mm with the one of the present invention.
Further, the minimum dimension of the cathode bar 13 was conventionally 10 mm, but in the cathode block 3 of the present invention, it is 20 mm. This is because in the conventional structure, the cathode rod 13 and the lead 17 are connected by the cap 16.
The height is increased due to structural and dimensional constraints (the height is large and the diameter of the cathode rod is small, and the cap 16 and stud 11 form a sealed container). In contrast, in the present invention, the restrictions of the conventional structure are removed, and the lead 17
Since the connection with the cathode block 3 can be made using the threaded portions 3a and 3b of the cathode block 3, the size (diameter) of the lead can be increased. Further, since the cathode block 3 is also structured to constitute a sealed container, the height dimension can be reduced and the diameter can be increased.

Therefore, when the diode of the present invention is used as a snubber for a gate turn-off thyristor, the inductance of the diode itself becomes smaller, and the spike voltage at turn-off becomes smaller, so the controllable current of the thyristor can be increased. . In addition, each base 1, cathode block 3
Since the is provided with a threaded portion, it is possible to use a thick lead for connection to an external circuit, and the inductance in the circuit is also reduced.

Although the above embodiments have been described with reference to the case where the present invention is applied to a diode, it goes without saying that the present invention is not limited thereto and can also be applied to thyristors, triaxes, and the like.

〔Effect of the invention〕

As described above, according to the flat base type semiconductor device of the present invention, the shape of the upper electrode constituting the sealed container for sealing the semiconductor element is made into a block shape, and the pressure member around the upper electrode is made of a non-magnetic material. Since the height dimension of the exterior electrode is short and the diameter can be made large, the device itself has the effect of reducing the inductance of the circuit.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a diode according to an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional stud-type diode. 1...base, _1-1 ...block, _1-2 ...case,
_1-3 ...Welding ring, 1a, 1b...Threaded part, 2...
Diode element, 3... Cathode block, 3 _-1 ... Flange part, 3 _-2 ... Welding ring, 3a, 3b... Threaded part, 4
…Insulation ring, 5…Disc spring (pressure member), 6…Cap, _6-1 …Insulator, _6-2 , _6-3 …Flange.

Claims (1)

[Claims] 1. A base serving as a lower electrode that houses a semiconductor element and is formed to surround the peripheral side of the semiconductor element, and a base that is placed on the upper surface of the semiconductor element housed in the base to form a sealed container thereof. The semiconductor device is pressed into contact with the semiconductor element sandwiched between the electrode block and the base by a pressure member made of a non-magnetic material inserted into the electrode block. A flat base type semiconductor device characterized in that the semiconductor element is hermetically sealed by sealing both ends of each of the base and electrode blocks with a sealing cap formed to surround the peripheral surface between the base and the electrode block. 2. The flat base type semiconductor device according to claim 1, wherein a mounting thread is provided on either or both of the base and the electrode block serving as the lower electrode.