JPH0289352A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a semiconductor device with improved cooling properties by embedding the head part of a clamping bolt into a cooling piece. CONSTITUTION:A cooling piece 14 is placed so that tip parts 18b, 18b of clamping bolts 18, 18 may be directed upward, an insulation plate 13, a current terminal 12, a semiconductor element 11, a current terminal 15, and an insulation plate 16 are piled up in sequence, and then nuts 19, 19 are clamped to the clamping bolts 18, 18 so that the insulation plate 16 may be pressed downward by a metal springy press pressure body 17. Thus, it is not necessary to form a cut part for mounting a bolt at a cooling surface 14a of the cooling piece 14 and the cooling surface 14a can be made larger by that amount. Namely, when the cooling surface 14a is mounted so that it may be held against the external cooling piece, the junction area between the cooling piece 14 and the external cooling piece can be made larger and heat generated during operation of the semiconductor element 11 can be efficiently transmitted from the cooling piece 14 to the external cooling piece, thus achieving an improved cooling performance.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrically insulated semiconductor device, and more particularly to an improvement in a bolt attachment mechanism for securing a heat dissipation portion thereof.

[Conventional technology]

Generally, electrically insulated semiconductor devices that use semiconductor elements such as high-power diodes and thyristors require heat radiation means to radiate heat generated by the operation of the semiconductor elements.

FIG. 2 is a partially cutaway side view showing a conventional semiconductor device of this type. As shown in the figure, one main electrode surface of the semiconductor element 1 provided in the center has a current terminal 2, an insulating plate 3 made of ceramic or the like having excellent thermal conductivity, and an insulating plate 3 made of ceramic or the like having excellent thermal conductivity, and Cooling pieces 4 made of conductive metal are stacked one after another. On the other hand, on the other main electrode surface of the semiconductor element 1, a current terminal 5, an insulating plate 6 made of ceramic or the like, and a metal elastic pressing body 7 such as a leaf spring are stacked.

Then, four tightening bolts 8, 8 (only two are shown in the figure) are passed through the four corners of the cooling piece 4 and the four corners of the metal elastic pressing body 7 from below the cooling piece 4, respectively, and tightening the nuts 9.9.
By fastening them, the laminate is held under pressure to form a semiconductor device.

The procedure for assembling this device is to first attach the cooling piece 4 to the tightening bolt 8.
8, and while fixing the tightening bolt 8.8 with a bolt fixing jig (not shown), insert the current terminal 2.8 through the insulating plate 3°. Semiconductor device 1. The current terminal 5 and the insulating plate 6 are stacked one on top of the other, and then the nuts 9, 9 are fastened to the tightening bolts 8, 8 so that the insulating plate 6 is pressed downward by the metal elastic pressing body 7.

In such a semiconductor device, the heat radiation surface 4 of the cooling piece 4
The heat generated during the operation of the semiconductor element 1 is transferred to the current terminals 2 . Heat is radiated to the external cooling piece (not shown) via the insulating plate 3 and the cooling piece 4 to be radiated to the outside.

[Problem to be solved by the invention]

In such a semiconductor device, it is desirable to secure a large area for the heat radiation surface 4a of the cooling piece 4 so that heat can be sufficiently radiated.However, in the conventional semiconductor device, the tightening bolt 8.
Since the cooling piece 4 is configured to be clamped under pressure, it is necessary to form notches 10 and 10 in the cooling piece 4 for bolt attachment, and the area of the heating surface 4a decreases, resulting in poor heat dissipation performance. However, there was a problem in that the current carrying capacity was reduced due to the accumulated heat.

It is an object of the present invention to solve the problems of the prior art described above and to provide a semiconductor device with excellent heat dissipation performance.

[Means to solve the problem]

In this invention, a first current terminal, a first insulating plate, and a cold uI piece are sequentially stacked on one main electrode surface of a semiconductor element, and a second current terminal, a second insulating plate are stacked on the other main electrode surface. A semiconductor device in which a laminate in which a plate J3 and an elastic pressing body are sequentially stacked is held under pressure by tightening bolts, and in order to achieve the above object, the head of the tightening bolt is embedded in the cooling piece. There is.

[Effect]

In the semiconductor device of the present invention, by embedding the head of the tightening bolt in one piece of the cold part, there is no need to form a notch for attaching the bolt on the heat radiation surface of the cooling piece, and the fractional heat surface is set large. can do.

〔Example〕

FIG. 1 is a partially cutaway side view showing a semiconductor device which is an embodiment of the present invention. As shown in the figure, this semiconductor device includes a semiconductor element 11, a current terminal 12.15, an insulating plate 13.16 made of ceramic or the like, a cooling piece 14 made of copper or aluminum, etc., and a plate spring or the like. The laminate consisting of the metal elastic pressing body 17 is secured with four tightening bolts 18.
18 (only two are shown in the figure) are semiconductor devices that are held under pressure. The heads 18a, 18a of the four tightening bolts 18.18 are embedded in advance in the four corners of the cold piece 14 by casting or die-casting. .18 tip 18b.

18b is passed through the metal elastic pressing body 17, and its tip 18
By screwing nuts 19 and 19 into b and 18b, the metal elastic pressing body 17 is pressed toward the cooling piece 4, thereby clamping the laminate under pressure.

The procedure for assembling this device is to first arrange the cooling piece 14 so that the tips 18b, 18b of the tightening bolts 18.degree.
The current terminal 15 and the insulating plate 16 are stacked one on top of the other, and then the nuts 19, 19 are fastened to the tightening bolts 18, 18 so that the insulating plate 16 is pressed downward by the metal elastic pressing body 17.

According to this semiconductor device, the heads 18a, 18a of the tightening bolts 18, 18 are buried inside the cooling piece 14, so that, for example, as in the conventional semiconductor device shown in FIG.
A notch 10 for bolt attachment is provided on the heat dissipation surface 14a of the I piece 14,
10, and the fractional heating surface 14a can be set large. In other words, when the heat dissipation surface 14a is mounted so as to be in pressure contact with an external cooling piece (not shown), a large joint area between the cooling piece 14 and the external cooling N1 piece can be secured, and the Heat is efficiently transferred from the cooling piece 14 to the external cooling piece, resulting in excellent heat dissipation performance. As a result, it is possible to prevent a decrease in current carrying capacity due to heat in the semiconductor device, for example.

In addition, since the tightening bolts 18 and 18 are fixed to the cold 11 piece 14, the above-mentioned second
In the conventional example shown in the figure, the necessary jig for fixing the tightening bolt is no longer necessary, simplifying the assembly work.

〔Effect of the invention〕

As described above, according to the semiconductor device of the present invention, since the head of the tightening bolt is embedded in the cooling piece, there is no need to form a notch for attaching the tightening bolt on the heat radiation surface of the cooling piece. ,
Accordingly, the heat dissipation surface of the cooling piece can be set larger and the effect of excellent heat dissipation performance can be obtained.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view showing a semiconductor device according to an embodiment of the present invention, and FIG. 2 is a partially cutaway side view showing a conventional semiconductor device. In the figure, 11 is a semiconductor element, 12.15 is a current terminal, 13.16 is an insulating plate, 14 is a cooling piece, 17 is a metal elastic pressing body, 18 is a tightening bolt, and 18a is a head. Note that the same reference numerals in each figure indicate the same or corresponding parts. 18a: Head 18b - Tip #19; Deato No. 25i11

Claims (1)

[Claims] (1) A first current terminal on one main electrode surface of the semiconductor element,
The first insulating plate and the cooling piece are sequentially stacked, and the second current terminal, the second insulating plate, and the elastic pressing body are sequentially stacked on the other main electrode surface, and the laminate is clamped under pressure with a tightening bolt. A semiconductor device characterized in that the head of the tightening bolt is embedded in the cooling piece.