JP2547790B2 - Stack for flat semiconductor devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a stack for a flat semiconductor device in which a flat semiconductor device and a heat sink are laminated and an elastic pressing force is applied.

(Prior Art) In recent years, a semiconductor conversion device (hereinafter referred to as a device) tends to have a large capacity (higher voltage), and accordingly, a large number of flat semiconductor elements (hereinafter referred to as elements) are used. The apparatus is a stack for flat semiconductor devices (hereinafter referred to as a stack) that is composed of a plurality of elements and heat sinks for cooling the elements that are alternately stacked to each other and that includes a holding plate, a stud, and a spring for holding an elastic pressing force. ) Is used as a large number of circuit components of the device.

In recent years, more and more compact devices have been required due to restrictions on installation location and space. However, increasing the capacity (increasing the voltage) of the device is not only due to the increase in the size of parts, but also to ensure the insulation distance between the products. This is a factor that conflicts with compactness.

The conventional stack used in the apparatus will be described below with reference to FIGS. 4 to 6.

Generally, the apparatus is constructed by mounting units called modules on a composite platform. FIG. 4 shows the circuitry within a typical module. The module 23 includes a plurality of elements 12,
(6 in series in the figure) and its associated circuit, the anode reactor 20, the voltage dividing resistor 21, and the capacitor 22, are housed, and the broken line portion is the stack 1.

FIG. 5 is a front view showing the stack 1 of FIG. 4, and FIG. 6 is a side view of the stack 1.

The stack 1 is formed by laminating a plurality of elements 12 (six in series in the figure) and a heat sink 11, and further laminating a conductor 10 which becomes an electric circuit connecting element, an insulating seat 9 and a seat 8 for electrical insulation on both ends thereof. The laminated body is composed of pressing plates 2-a and 2-b for holding elastic pressing force, studs 3, disc springs 4, disc spring pressing plates 5 and tightening nuts 6.

Conventionally, the stud 3 is made of steel, and is threaded at both ends. As shown in the figure, one end is fixed to the screw hole drilled in the holding plate 2-a and the other end is a through hole in the holding plate 2-b. Insert the disc spring 4 and insert the disc spring retainer plate 5 and tighten the nut 6.
Considered to be tightened in. Here, the disc spring 4 absorbs the thermal expansion of the element 12 itself due to the heat loss of the element 12 during the operation of the device and the fluctuation of the pressurizing force due to the thermal expansion of the heat sink 11 which cools the element 12, and is kept below the allowable pressurizing force of the element. It has the function of elastically maintaining pressure.

(Problems to be Solved by the Invention) Since the pressing plates 2-a and 2-b are electrically at the same potential as the stud 3, the heat sink 11 at the central portion of the stack 1 is usually provided.
And the pressing plate 2-b (or 2-a) are electrically connected by an electric wire so as to have the same potential as the heat sink in the center of the stack.
Therefore, both ends of the laminated body of the plurality of elements 12 and the heat sink 11 and the electric potentials of the pressing plates 2-a and 2-b are different, and therefore stacking is performed via the insulating seat 9. Further, the stud 3 is usually surface-coated with an insulating material such as epoxy or Teflon except the screw portions at both ends so as not to generate a discharge phenomenon such as corona. Of course, it is necessary to secure a sufficient space insulation distance L between the stud 3 and the laminated body of the element 12 and the heat sink 11. This space insulation distance L basically increases in proportion to the product of the voltage shared by the elements and the number of elements stacked. These were factors that contradicted the requirements for simplification and compactness. In addition, increase the capacity of the device (higher voltage)
Since a large number of elements and heat sinks are integrated into one stack because of the simplification required, the volume occupied by the stack 1 in the module 23 is increased because it is necessary to secure a certain insulation distance L. Not only
It is also necessary to increase the bending strength by increasing the thickness t of the pressing plate so that the amount of deflection of the pressing plate does not increase when pressure is applied due to the length l of the pressing plates 2-a and 2-b increasing. There was a problem that the weight was extremely increased.

Furthermore, the conventional semiconductor stack has two tightening nuts 6
Although the pressurizing force is held by, the loosening of the tightening nut 6 causes some play even though the stud 3 is screwed into the holding plate 2-a. It is necessary to pressurize this rattling, and to tighten the two tightening nuts 6 alternately so that there is no unevenness of the pressurization, so that a predetermined pressure is applied. At that time, a certain amount of space was required due to the tools, and it was difficult to replace the element while it was still incorporated in the normal device.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the problems of the conventional example, and to provide a stack for flat semiconductor devices which is simple, compact, lightweight and easy to stack.

[Means for Solving the Problems] (Means for Solving the Problems) In order to solve the above-mentioned problems, instead of the studs forming the stack, an insulating material flat plate made of glass cloth laminated reinforced plastic or the like is used. The first feature is that the stacking frame is composed of two sheets, and then the both ends are pressed down as a mechanism for pressing and holding the stacked body formed by stacking a plurality of flat semiconductor elements and a plurality of heat sinks with elastic pressing force. The plate is provided with a through hole along the laminated body, a pressure rod that can be freely moved is attached to the through hole of one of the pressing plates, and the pressure rod is threaded to provide a lock nut. The second feature is that a disc spring rod having a disc spring mounted therein is provided in the through hole of the holding plate of No. 2, and further, a pressing force is applied to the pressurizing cylinder so that the device and the heat sink Pressure unit according to pressure allowed to example handheld hydraulic layer body is a third feature in that to allow provided on the holding plate.

(Operation) With the configuration described above, it is not necessary to secure the spatial distance L shown in FIG. 5 due to the above-mentioned first feature. That is, since the conventional stud uses an electrically conductive steel material, it serves as an electrode having a certain potential, and the laminated body of the element and the heat sink also serves as an electrode having a certain potential distribution. However, it is not necessary to secure the space distance L by forming the stud with an insulating material flat plate. In addition, when the pressing plate and the insulating flat plate are fixed, the fibers forming the insulating flat plate, for example, in the case of a glass cloth mat laminated plate, are pulled by considering the fixing to the pressing plate so that a force is applied in the direction along the laminated plate. It is used to demonstrate the characteristics of the glass cloth mat laminate, which is strong against force. Further, the insulating seat 9 shown in FIG. 5, which was necessary as a constituent element of the conventional stack, is unnecessary. Of course, the electric wire 7 for fixing the electric potential is also unnecessary. The first feature described above enables the stack to be simplified and made compact.

Further, according to the second characteristic described above, it is possible to have an action of pressing and holding a laminated body in which a plurality of elements and heat sinks are laminated alternately by elastic pressing force. In particular, by mounting the disc spring by passing the disc spring rod through the disc spring, the sitting (stability) at the time of pressurizing the stack is improved. Further, after pressing the laminated body by applying a pressing force to the pressing rod from the outside, the pressure can be retained by the lock nut of the pressing rod.

With the third feature, when the pressure unit is attached, the pressure applied to the stack can be easily released anywhere to replace the element, and the pressure can be applied again to maintain the elastic pressure contact force. That is, it is possible to easily replace the elements as they are without removing the stack assembled in the module unit from the module. This makes it possible to easily release stacking and re-pressurize by simply attaching a pressure unit utilizing the mechanism of the pressure rod, which is the second feature of the present invention, to the stack.

(Example) Hereinafter, the present invention will be described with reference to FIGS.

FIG. 1 is a front view of a stack for a flat semiconductor device of the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 is a pressurizing unit diagram described in the present invention.

As shown in FIG. 1, an insulating flat plate 25 such as a glass cloth laminated material is fixed to the holding plate 2 with mounting bolts 15 to form a frame for stacking, and the holding plate 2 at both ends has flat semiconductor elements 12 and Through holes along the stack of heat sinks 11
24 is provided, a pressure rod 13 that can be freely moved is provided in the through hole 24 of one holding plate, this pressure cylinder is threaded and a lock nut 26 is attached, and a through hole of the other holding plate is provided.
24 is provided with a disc spring rod 14 which is freely movable and to which the disc spring 4 is attached. In addition, the through hole 24 of the pressing plate 2, the pressure rod 13,
A stack of flat semiconductor elements 12 and the like, and disc spring rods 14 are arranged so as to coincide with the pressing axis. Pressurization at the time of stacking is performed by attaching the pressurizing unit 16 shown in FIG. 3 to the holding plate 2 by an appropriate method. The pressurizing unit 16 is constructed by fixing a hydraulic cylinder 17 to a mounting jig 19. Although not shown in the figure, the hydraulic pressure from a hydraulic pump, etc. is transmitted to the hydraulic cylinder 17 by the hydraulic hose 18 to press the pressure rod 13 and when the appropriate pressure is applied, the lock nut mounted on the pressure rod 13
The pressing rod 13 is fixed by tightening 26 on the holding plate 2 side to maintain the elastic pressing force of the semiconductor stack.

〔The invention's effect〕

As described above, according to the present invention, it is possible to provide a flat semiconductor device stack that is simple, compact, lightweight, and is easy to replace.

[Brief description of drawings]

1 is a front view of a semiconductor stack of the present invention, FIG. 2 is a side view of FIG. 1, FIG. 3 is a view showing a pressurizing unit for pressurizing the stack of the present invention, and FIG. 4 is a conversion device. FIG. 5 is a front view showing a conventional semiconductor stack, and FIG. 6 is a side view of FIG. 1 ... Stack, 2 ... Holding plate 3 ... Stud, 4 ... Disc spring 5 ... Holding plate, 6 ... Tightening nut 7 ... Electric wire, 8 ... Seat 9 ... Insulating seat, 10 ... Conductor 11 …… Heat sink, 12 …… Flat semiconductor 13 …… Pressure rod, 14 …… Disc spring rod 15 …… Pressure bolt, 16 …… Pressure unit 17 …… Hydraulic cylinder, 18 …… Hydraulic hose 19 …… Mounting jig, 26 …… Anode reactor 21 …… Voltage dividing resistor, 22 …… Capacitor 23 …… Module, 24 …… Through hole 25 …… Insulating flat plate, 26 …… Lock nut

Claims (1)

(57) [Claims] 1. A laminated body in which a plurality of flat semiconductor elements and a heat sink are laminated, a pair of insulating material flat plates made of glass cloth epoxy reinforced resin or the like arranged on both sides of the laminated body in parallel with the laminated body, A pair of holding plates that are orthogonal to the insulating flat plate and are fixed to the insulating flat plate near both ends of the insulating flat plate, and the center line of the laminated body matches the center of the through holes of the pair of holding plates. The through hole provided in the holding plate and the disc spring are mounted so that one end is in contact with one end of the laminate and the other end is inserted into the through hole of the one holding plate, and freely movable in the stacking direction of the laminate. And a conical spring rod that is threaded and has one end in contact with the other end of the laminate and the other end through a through hole in the other holding plate to which a pressure unit utilizing hydraulic pressure can be detachably attached. And freely in the stacking direction of the stack A movable pressure rod, and a lock nut that is provided inside one end of the pressure rod and the other pressing plate and that is screwed to the pressure rod. A stack for flat semiconductor devices, characterized in that the pressing unit is removed after the lock nut is tightened to the inside of the other pressing plate after the pressing force is applied.