JPH06177292A - Semiconductor stack - Google Patents

Abstract

PURPOSE:To provide a semiconductor stack, in which uniform contact of flat semiconductor elements with cooling pieces is maintained and the replacement of elements is facilitated, by inserting a plate penetrated by studs in the middle of the stack. CONSTITUTION:Flat power semiconductor elements 1 are stacked alternately with cooling pieces 2, and the stack is clamped at opposite ends by using studs 9. In the middle of the stack, a plate 14 is provided between two cooling pieces 2, and it is penetrated by the studs and secured by a fixture 3. Since the alternate stack of flat semiconductors and cooling pieces is supported in the middle by the studs and the plate, the heat transfer to the cooling pieces is sufficient without the need for reducing the number of semiconductor elements, and it is easy to replace elements.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor stack formed by alternately stacking a plurality of flat elements and cooling pieces.

[0002]

2. Description of the Related Art As is well known, a plurality of hand-shaped elements (hereinafter referred to as
In order to increase the heat transfer efficiency between the element that becomes the heating element and the cooling piece that absorbs the heat of the element In addition, the element and the cooling piece are clamped from both sides.

FIG. 6 is a plan view showing a conventional stack, FIG. 7 is a front view of FIG. 6, and FIG. 8 is a sectional view taken along line BB of FIG. 6, FIG. 7 and FIG. 8, in the stack, the cold piece 2 and the element 1 are alternately stacked on the left and right of the insulator 4A incorporated in the middle portion (Note; in FIG.
And 4 pieces of cooling pieces 2), and insulators 4B are respectively stacked on both ends thereof, and conical seats 8 are stacked further on the outer sides of the insulators 4B with the apex sides inside. In the right side view (not shown), strip-shaped pressure plates 7 are further stacked on the outer side of each.

A pair of screw bolts 29 are inserted between the left and right pressure plates 7, and the pressure plates 7 are attached to the screw bolts 29.
A plurality of disc springs 6 are inserted back to back on the outside of the disc, and an L-shaped mounting plate 5 in FIG. 7 is inserted on the outside of the disc spring 6 and the outside of the pressure plate 7 on the right side.

A nut 10A is provided on the outside of these mounting plates 5.
Is inserted from the outside of each screw bolt 29, and each nut 10A
Is an element 1 with a dedicated small hydraulic press or torque wrench.
It is tightened so that the specified tightening force is determined by the rating and type.

FIG. 9 shows a case where the stack shown in FIGS. 6 and 7 is applied to a high voltage circuit, and a plurality of insulators are provided between the lower surface of the mounting plate 5 at the left and right ends and the mounting surface of the stack. Four
C is overlaid. In addition, the cooling piece 2 located in the central portion
And the mounting plate 5 at the right end are connected by an electric wire 17, and as a result, the cooling piece 2 and the mounting plate 5 located at the central portion are made to have the same potential, and the insulator 4B is downsized.

In the stack constructed as described above, bolts 12 having oval holes formed at the front and rear of the lower ends of the left and right mounting plates 5 are inserted into the box in which the stack is housed, as shown in FIG. It is fixed horizontally or vertically. On the other hand, a cooling pipe (not shown) is connected to a pair of pipe joints (not shown) screwed to each cooling piece 2, and distilled water is circulated through this cooling pipe to cool the element 1 that has been heated by energization. ing.

When replacing the element 1 of this stack, first, as shown in FIG. 7 and FIG. 8 which is a sectional view taken along line BB of FIG. 7, a rectangular plate-shaped element replacement jig 13 is stacked. And a mounting surface of the stack, and a spacer is inserted between the lower surface of the element exchange jig 13 and the mounting surface of the stack to form a recess 13a formed in the center of the upper surface of the element exchange jig 13.
The upper surface of is contacted with the lower surface of the cooling piece 2.

Next, loosen the nut 10A on one side which is tightening the element 1 and the cooling piece 2 through the both screw bolts 29, and replace both sides of the element 1 to be replaced and the cooling pieces 2 on the left and right sides of the element 1.
A jig is inserted between and the target element 1 is taken out.

The element replacement jig 13 is used to prevent the cooling piece 2 from slipping when the nut 10A is loosened, and is made of a fluororesin material having a small friction coefficient in order to facilitate the insertion work with the mounting surface. It is manufactured.

[0011]

However, in the stack having such a structure, when the number of the elements 1 and the cooling pieces 2 stacked on each other increases due to the voltage of the power semiconductor circuit to which the stack is connected, the stack is increased. Figure 7
When stored horizontally on the mounting surface of the box as shown in,
The center portion of the element 1 and the cooling piece 2 bend downward due to their own weight, and an unbalanced load is applied to the contact surfaces of each element 1 and the cooling pieces 2 that are stacked on both sides of each element 1 (Note: the tightening force is not uniform). Is added.
Then, due to the decrease in the contact area between each element 1 and the cooling pieces 2 stacked on both sides of each element 1, the heat transfer characteristics between them are impaired, and the temperature rise value of each element 1 is allowed. May exceed.

When the element 1 is replaced as described above, the nut 10A is used to mount the jig 13 and replace the element 1.
When tightening, it is necessary to confirm whether the element 1 sandwiched between the cooling pieces 2 is not displaced and further confirm a predetermined torque, so that the replacement work takes time, It may not be possible within the maintenance time of.

Therefore, when the number of elements 1 increases,
A method of increasing the number of stacks and reducing the number of elements 1 to be stacked has also been adopted. However, since the number of stacks and the assembling work increase accordingly, not only the assembly time of the power semiconductor device becomes longer, but also Since the storage area also increases, there is also a drawback that the box housing the power semiconductor device incorporating this stack becomes large.

Therefore, an object of the present invention is to provide a semiconductor stack in which the reduction of heat transfer to a cooling piece can be prevented and the elements can be easily replaced without reducing the number of elements to be stacked.

[0015]

According to a first aspect of the present invention, there is provided a semiconductor stack in which a plurality of power semiconductor elements and a plurality of cooling pieces are alternately stacked and fastened with studs from both ends. A sandwiching plate through which the intermediate part of the stud penetrates is interposed between the cooling pieces of the part.

According to a second aspect of the present invention, in a semiconductor stack in which a plurality of power semiconductor elements and a plurality of cooling pieces are alternately stacked and fastened with studs from both ends, between the cooling pieces in the middle part of the semiconductor stack. In addition, a sandwiching plate of an insulating material that penetrates the intermediate portion of the stud is interposed.

According to a third aspect of the present invention, in a semiconductor stack in which a plurality of power semiconductor elements and a plurality of cooling pieces are alternately stacked and fastened with studs from both ends, between the cooling pieces in the middle part of the semiconductor stack. And a sandwiching plate through which an intermediate portion of the stud penetrates, the stud is locked to the sandwiching plate from one side of the stack, and the power semiconductor element on one side of the stack is tightened from this sandwiching plate.
And the other side of the stack from the other side of the stack.
It is characterized in that it is constituted by a second stud for fastening the power semiconductor element on the other side of the stack from the sandwich plate.

According to a fourth aspect of the invention, in a semiconductor stack in which a plurality of power semiconductor elements and a plurality of cooling pieces are alternately stacked and fastened with studs from both ends, between the cooling pieces in the middle part of the semiconductor stack. In addition, a sandwiching plate through which the intermediate portion of the stud penetrates is interposed, and a support tool is attached to this sandwiching plate.

According to a fifth aspect of the present invention, in a semiconductor stack in which a plurality of power semiconductor elements and a plurality of cooling pieces are alternately stacked and fastened with studs made of a metal material from both ends, cooling of an intermediate portion of the semiconductor stack is performed. A sandwich plate made of a metal material, through which the intermediate portion of the stud penetrates, was interposed between the pieces, and a support tool was attached to the sandwich plate, and an insulator was interposed between both ends of the support tool and the stud and the attachment portion. It is characterized by

[0020]

In the invention described in claim 1, the intermediate portions of the power semiconductor elements and the cooling pieces, which are alternately stacked, are supported by the stud through the sandwiching plate. In the invention described in claim 2, the intermediate portions of the power semiconductor elements and the cooling pieces, which are alternately stacked, are supported by the studs via the sandwiching plate of the insulating material. According to the third aspect of the invention, the intermediate portions of the power semiconductor elements and the cooling pieces, which are alternately stacked, are supported by the first studs and the second studs via the sandwiching plate. In the invention according to claim 4, the intermediate portions of the power semiconductor elements and the cooling pieces, which are alternately stacked, are supported by the support via the sandwiching plate.

According to a fifth aspect of the present invention, the intermediate portions of the power semiconductor elements and the cooling pieces, which are alternately stacked, are supported by the support via the sandwiching plate, and the intermediate portions are the end portions of the studs. Is equipotential and is insulated from the installed potential part.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the semiconductor stack of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a semiconductor stack of the invention described in claims 1, 2, 3 and 4, and is a view corresponding to FIG. 8 shown in the prior art, and FIG.
FIG. 10 is a front view corresponding to FIG. 9. 1 and FIG. 2 are different from the conventional FIG. 8 and FIG. 9 in that two insulators 4A are used in the central portion of the stack, and between the insulators 4A are shown in FIG. 8 and FIG. A sandwiching plate 14 having substantially the same shape as that of the pressure plate 7 is stacked, and the upper end of the support fitting 3 shown in FIG. 2 is fixed to the front and rear of this sandwiching plate 14 in FIG.

That is, in FIGS. 1 and 2, the screw plate 9 inserted in the central portion is penetrated by the both screw bolts 9A in the front and rear direction, and the center portion of the both screw bolts 9A is shown in detail in the portion A of FIG. As shown in FIG. 3A showing the enlarged cross-sectional view, a male screw 9a having an inner diameter slightly larger than the outer diameter of the unthreaded portion of the both-threaded bolt 9A is formed. This male screw 9
Nuts 10B are respectively screwed into a from both sides of the sandwich plate 14 to tighten the sandwich plate 14 from both sides.

Further, below the sandwiching plate 14, the upper end of the L-shaped support metal fitting 3 shown in FIG. 2 is fixed to the front and rear right side surfaces in FIG. The lower end is fixed by a bolt (not shown) to the mounting surface of the box body of the power semiconductor device in which this stack is housed.

In the stack thus constructed, even if the number of the stacked elements 1 and cooling pieces 2 increases, the central portion of the stack is attached to the box mounting surface by the support metal 3 via the sandwiching plate 14. Since it is supported by, it is possible not only to prevent the stack from flexing, but in FIGS. 1 and 2, for example, when replacing the element 1 incorporated on the right side of the support fitting 3, the right end of both screw bolts 9A is replaced. Nut 10
When loosening A, the element 1 stacked on the left side of the support metal fitting 3 is not likely to be displaced downward, so that the range for checking the presence or absence of misalignment can be reduced, and the work at the time of element replacement is facilitated. .

Further, when the ratings of the left and right elements of the sandwich plate 14 are different and the pressure contact force with the cooling piece 2 is different, the right end nut 10A is changed by changing the tightening torque of the left end nut 10A. There is also an advantage that can be done.

In addition, in FIGS. 1 and 2, the sandwiching plate 14 is used.
May be a metal material, but may be the invention according to claim 2 as an insulating plate such as an FRP material. In this case, since the insulator 4A mounted in the middle is unnecessary, the length of this stack can be shortened. Further, in FIG. 3, the nut 10B may be omitted by screwing the male screw portion 9a of the central portion of the stud 14 with the through hole of the stud 14 provided in the sandwich plate 14 as a screw hole.

1 and 2, the support fitting 3
The invention according to claim 1 may be omitted. Even in this case, the load of the element 1 and the cooling piece 2 in the middle part of the stack is
Since it is supported by both screw bolts 9A, it is possible to reduce downward bending, prevent uneven contact of the contact surface between the element 1 and the cooling piece 2, and prevent deterioration of heat transfer characteristics from the element 1 to the cooling piece 2. You can

In FIG. 3B, the holes provided in the front and rear of the sandwich plate 14 are used as female screw holes, and the double screw bolt 9B is shown in FIGS.
As a half length of the double-screw bolt 9A shown in Fig. 3, one side of the double-screw bolt 9B is screwed into the female screw hole of the sandwiching plate 14 to show the case of the invention. Also in this case, by using the support fitting 3, it is possible to prevent the element 1 and the cooling piece 2 from bending and the element on one side from being displaced when the element is replaced.

FIG. 4 and FIG. 5 are views showing an example of a stack connected to a high voltage circuit, and FIG.
5 is a front view of FIG. 4. In FIGS. 4 and 5, the stack shown in FIGS. 1 and 2 is fixed to the mounting surface via the insulator 4C shown in FIG. 9, and a mild steel plate is used for the sandwich plate. In this case, there is an advantage that the connection between the cooling piece in the middle portion and the mounting plate 5 by the electric wire 17 shown in FIG. 9 is unnecessary.

[0031]

As described above, according to the invention of claim 1,
In a semiconductor stack in which a plurality of power semiconductor elements and a plurality of cooling pieces are alternately stacked and tightened with studs from both ends, a sandwiching plate through which the middle portion of the stud penetrates is provided between the cooling pieces in the middle portion of the semiconductor stack. By interposing, the intermediate portions of the power semiconductor elements and the cooling pieces, which are alternately stacked, are supported by the studs via the sandwich plate, so that the heat transfer to the cooling pieces can be prevented without reducing the number of stacked elements. It is possible to obtain a semiconductor stack in which deterioration can be prevented and elements can be easily replaced.

According to a second aspect of the present invention, a plurality of power semiconductor elements and a plurality of cooling pieces are alternately stacked,
In a semiconductor stack clamped by studs from both ends, a power semiconductor device that is alternately stacked by interposing a sandwich plate of an insulating material that penetrates the intermediate part of the stud between cooling pieces in the intermediate part of the semiconductor stack. Since the middle part of the cooling piece and the cooling piece are supported by the studs via the sandwich plate of the insulating material, the reduction of heat transfer to the cooling piece can be prevented and the elements can be easily replaced without reducing the number of stacked elements. A workable semiconductor stack can be obtained.

Further, according to the invention of claim 3,
In a semiconductor stack in which a plurality of power semiconductor elements and a plurality of cooling pieces are alternately stacked and tightened with studs from both ends, a sandwiching plate through which the middle portion of the stud penetrates is provided between the cooling pieces in the middle portion of the semiconductor stack. With the interposition, the stud is locked to the sandwich plate from one side of the stack, and the first stud that clamps the power semiconductor element on one side of the stack from this sandwich plate and the other side of the stack is locked to the sandwich plate. By configuring the second studs for fastening the power semiconductor element on the other side of the stack from the sandwich plate, the intermediate portions of the power semiconductor elements and the cooling pieces, which are alternately stacked, are sandwiched between the first stud and the second stud. Since it is supported by the studs, it is possible to prevent the reduction of heat transfer to the cooling piece without reducing the number of stacked elements and to easily replace the elements. It is possible to obtain a click.

Further, according to the invention of claim 4,
In a semiconductor stack in which a plurality of power semiconductor elements and a plurality of cooling pieces are alternately stacked and tightened with studs from both ends, a sandwiching plate through which the middle portion of the stud penetrates is provided between the cooling pieces in the middle portion of the semiconductor stack. By interposing and attaching a support tool to this sandwich plate, the intermediate portions of the power semiconductor elements and the cooling pieces that are alternately stacked are supported by the support tool via the sandwich plate, so the number of stacked elements can be reduced. In addition, it is possible to obtain a semiconductor stack in which a decrease in heat transfer to the cooling piece can be prevented and elements can be easily replaced.

Further, according to the invention of claim 5,
In a semiconductor stack in which a plurality of power semiconductor elements and a plurality of cooling pieces are alternately stacked and fastened with studs made of a metal material from both ends, the middle portion of the stud penetrates between the cooling pieces in the middle portion of the semiconductor stack. By interposing a sandwich plate made of a metal material, attaching a support tool to this sandwich plate, and interposing an insulator between both ends of the support tool and the stud and the mounting part, the power semiconductor elements and the cooling layers stacked alternately are cooled. The middle part of the piece is supported by the support through the sandwich plate, and the middle part is made to have the same potential as the end of the stud and is insulated from the installed potential part, so that the number of elements to be stacked is reduced. In addition, it is possible to obtain a semiconductor stack in which a decrease in heat transfer to the cooling piece can be prevented and elements can be easily replaced.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a semiconductor stack of the present invention according to claims 1, 2, 3 and 5.

FIG. 2 is a front view of FIG.

3A is a partially enlarged cross-sectional view of FIG. (B) is
The partial expanded sectional view which shows one Example of the semiconductor stack of invention of Claim 3.

FIG. 4 is a plan view showing an embodiment of the semiconductor stack of the invention described in claim 5;

5 is a front view of FIG.

FIG. 6 is a plan view showing an example of a conventional semiconductor stack.

7 is a front view of FIG.

8 is a sectional view taken along line BB of FIG.

9 is a front view showing an example of a conventional semiconductor stack different from that in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Flat element, 2 ... Cooling piece, 3 ... Support metal fittings, 4A, 4
B, 4C ... Insulator, 5 ... Mounting plate, 6 ... Disc spring, 7 ... Pressure plate, 8 ... Conical seat, 9 ... Double screw bolt.

Claims (5)

[Claims] 1. In a semiconductor stack in which a plurality of power semiconductor elements and a plurality of cooling pieces are alternately stacked and fastened with studs from both ends, an intermediate portion of the stud is provided between the cooling pieces in an intermediate portion of the semiconductor stack. A semiconductor stack characterized in that a sandwiching plate through which a portion penetrates is interposed. 2. In a semiconductor stack in which a plurality of power semiconductor elements and a plurality of cooling pieces are alternately stacked and fastened with studs from both ends, an intermediate portion of the stud is provided between the cooling pieces at an intermediate portion of the semiconductor stack. A semiconductor stack, characterized in that a sandwiching plate of an insulating material, through which a portion penetrates, is interposed. 3. In a semiconductor stack in which a plurality of power semiconductor devices and a plurality of cooling pieces are alternately stacked and fastened with studs from both ends, an intermediate portion of the stud is provided between the cooling pieces at an intermediate portion of the semiconductor stack. A first stud that interposes a sandwiching plate through which the portion penetrates, and that locks the stud from one side of the stack with the sandwiching plate and tightens the power semiconductor element on one side of the stack from the sandwiching plate; A semiconductor stack comprising: a second stud that is locked to the sandwich plate from the other side of the stack and clamps the power semiconductor element on the other side of the stack from the sandwich plate. 4. In a semiconductor stack in which a plurality of power semiconductor elements and a plurality of cooling pieces are alternately stacked and fastened with studs from both ends, an intermediate portion of the stud is provided between the cooling pieces at an intermediate portion of the semiconductor stack. A semiconductor stack, characterized in that a sandwiching plate through which a part penetrates is interposed, and a support is attached to the sandwiching plate. 5. A semiconductor stack in which a plurality of power semiconductor elements and a plurality of cooling pieces are alternately stacked and fastened with studs made of a metal material from both ends, and between the cooling pieces in an intermediate portion of the semiconductor stack, A metal sandwiching plate through which the middle part of the stud penetrates is interposed, a support is attached to the sandwiching plate, and an insulator is interposed between the support and both ends of the stud and the mounting portion. Semiconductor stack.