JP2005072249A - Method for fixing semiconductor discrete part and discrete semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for fixing a semiconductor discrete part which can reduce a size by suppressing overheating of the semiconductor discrete part, and to provide a discrete semiconductor device. <P>SOLUTION: The discrete semiconductor device 1 includes a structural material 2 built on a protruding part 3 of substantially the same height as the upper surface of the semiconductor discrete part 51 provided at the end of a heatsink 52, in such a manner that the structural material 2 and the protruding part 3 of the heatsink 52 are fixed with a metallic screw 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for fixing a semiconductor discrete component provided on a heat sink and a discrete semiconductor device.

  In general, electronic components such as transformers and electrolytic capacitors are highly exothermic electronic components, which may cause damage to themselves and other electronic components. Therefore, it is necessary to efficiently release the heat generated in the electronic component so that the heat does not affect other electronic components.

  As one method for releasing heat generated in an electronic component, there is a method in which the electronic component is brought into contact with a member having high heat dissipation called a heat sink, and the heat generated in the electronic component is released through the heat sink. (For example, refer to Patent Document 1 or 2) By making the contact surface between the electronic component and the heat sink as large as possible, heat generated in the electronic component can be efficiently released.

Moreover, since a large current flows also in semiconductor discrete components such as diodes and transistors, the electronic components have high heat generation. And such a semiconductor discrete component needs to discharge | release heat | fever efficiently like a transformer and an electrolytic capacitor.
By the way, a plurality of semiconductor discrete components are often mounted side by side on a heat sink. Various methods have been considered as a method for fixing a plurality of semiconductor discrete components to a heat sink.

FIG. 5A is a diagram illustrating an example of a discrete semiconductor device in which a semiconductor discrete component is fixed to a heat sink by an existing fixing method.
In the discrete semiconductor device 50 shown in FIG. 5A, a plurality of semiconductor discrete components 51 are respectively fixed on the heat sink 52 by M3 screws 53 (φ3 mm). The discrete semiconductor device 50 includes a water cooling type cooling unit in which a water channel 54 is provided in the heat sink 52. The semiconductor discrete component 51 is, for example, a transistor covered with a resin 55, and an insulating heat transfer sheet 57 having high thermal conductivity is provided between the metal base 56 of the transistor and the heat sink 52.

FIG. 5B is a diagram illustrating an example of a discrete semiconductor device in which a semiconductor discrete component is fixed to a heat sink by another existing fixing method. In addition, the same code | symbol is attached | subjected to the same structure as Fig.5 (a).
The discrete semiconductor device 58 shown in FIG. 5B has a small space portion on the upper surface of the semiconductor discrete component 51 pressed by a minimal portion of a metal spring plate-like clip 59, and clamps 60 provided at both ends of the clip 59 are heat sinks. The semiconductor discrete component 51 is fixed to the heat sink 52 by being hooked on a predetermined counterbore 52 (a groove corresponding to the shape of the clamp 60 in order to prevent the clamp 60 from being removed). (For example, see Patent Document 3)
Japanese Patent Laid-Open No. 2001-257485 (pages 3 to 4, FIG. 1) JP 2002-290088 (pages 5-8, FIG. 1) JP 2000-22370 (3rd page, Fig. 1)

  However, in the discrete semiconductor device 50 shown in FIG. 5A, the M3 screw 53 is passed through the semiconductor discrete component 51, and the protruding portion (male screw portion) of the remaining M3 screw 53 and a predetermined screw hole (female) of the heat sink 52. Since the semiconductor discrete component 51 is fixed to the heat sink 52 by screwing with the screw portion), the heat sink 52 needs to be thickened to some extent in consideration of the length of the screw hole. Therefore, when the length of the screw hole of the heat sink 52 is included, the thickness A shown in FIG. 5A increases, and there is a problem that it is difficult to downsize the discrete semiconductor device 50 in the thickness direction.

  Further, in the discrete semiconductor device 58 shown in FIG. 5B, only a small space portion on the upper surface of the semiconductor discrete component 51 can be held by the minimal portion of the clip 59, so that no uniform force is applied to the semiconductor discrete component 51. For this reason, the semiconductor discrete component 51 and the heat sink 52 cannot be sufficiently brought into contact with each other, and the semiconductor discrete component 51 may be overheated.

  Further, in order to prevent short circuit between the metal base 56 of the semiconductor discrete component 51 and the clip 59, it is necessary to open a certain distance between the semiconductor discrete component 51 and the clip 59 in consideration of a margin of the clip 59. Therefore, the interval B shown in FIG. 5B is increased, the area of the discrete semiconductor device 58 is increased, and it is difficult to reduce the size.

  Further, in order to provide a counterbore on the heat sink 52, it is necessary to make the heat sink 52 thick to some extent. Therefore, when the countersink of the heat sink 52 is included, the thickness C shown in FIG. 5B is increased, and there is a problem that it is difficult to reduce the size of the discrete semiconductor device 50 in the thickness direction.

  In view of the above problems, an object of the present invention is to provide a semiconductor discrete component fixing method and a discrete semiconductor device capable of suppressing overheating of the semiconductor discrete component and reducing the size of the entire device. To do.

In order to solve the above problems, the present invention adopts the following configuration.
That is, in the method for fixing a semiconductor discrete component according to the present invention, the entire upper surface of the semiconductor discrete component provided above the heat sink via the insulating heat transfer sheet is pressed by the structural material, and is provided inside the structural material by the fixing member. The metal collar and the heat sink are fixed.

Thus, since the entire upper surface of the semiconductor discrete component is pressed by the structural material, the semiconductor discrete component can be adhered to the heat sink. Thus, overheating of the semiconductor discrete component can be suppressed.
Moreover, since the structural material and the heat sink are fixed by the fixing member, a plurality of semiconductor discrete components can be fixed by one structural material. As a result, the semiconductor discrete components can be brought closer to each other than the case where the semiconductor discrete components are fixed with a clip, so that the discrete semiconductor device can be downsized.

In the method for fixing a semiconductor discrete component, a rib may be provided on the structural material. Thereby, the strength of the structural material can be increased.
In the fixing method of the semiconductor discrete component, a metal plate may be provided inside the structural material. Thereby, the strength of the structural material can be increased.

  In the fixing method of the semiconductor discrete component, the metal plate may be configured as a wiring for supplying electric power to the semiconductor discrete component. As a result, there is no need to provide a wiring arrangement space, so that the discrete semiconductor device can be reduced in size. In addition, the manufacturing process of the discrete semiconductor device can be facilitated.

  The scope of the present invention includes a heat sink, a semiconductor discrete component provided above the heat sink, and provided between the heat sink and the semiconductor discrete component, and transmits heat generated in the semiconductor discrete component to the heat sink. An insulating heat transfer sheet made of an insulating material, a structural material that holds the entire upper surface of the semiconductor discrete component and fixes the semiconductor discrete component on the insulating heat transfer sheet, and a heat sink and the structural material. The present invention extends to a discrete semiconductor device including a fixing member to be fixed and a metal collar provided at a fastening portion between the heat sink and the fixing member inside the structural material.

According to the present invention, it is possible to suppress overheating of the semiconductor discrete component.
In addition, the discrete semiconductor device can be reduced in size.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a discrete semiconductor device according to an embodiment of the present invention. In addition, the same code | symbol is attached | subjected about the same structure as FIG. In addition, the discrete semiconductor device 1 according to the embodiment of the present invention is configured such that fluid such as water, refrigerant, or air passes through the heat sink 52.

  A discrete semiconductor device 1 shown in FIG. 1 includes at least a surface of a semiconductor discrete component 51 made of a structural material 2 (for example, a thickness of about 4 to 5 mm) formed of a resin (for example, PBT (PolyButylene Terephthalate) including glass). The upper surface is pressed and the semiconductor discrete component 51 is fixed to the heat sink 52.

  Specifically, in the discrete semiconductor device 1, the structural material 2 is placed on the convex portion 3 that is almost the same height as the upper surface of the semiconductor discrete component 51 provided at the end of the heat sink 52. The convex portion 3 of the heat sink 52 is fixed by a metal (for example, brass) screw 4 (fixing member). Thus, the upper surface of the semiconductor discrete component 51 can be pressed by the structural material 2, and the semiconductor discrete component 51 can be fixed to the heat sink 52.

  In addition, as shown in FIG. 1, when the semiconductor discrete component 51 is a transistor, it is formed of an elastic material such as gel or rubber between the semiconductor discrete component 51 and the heat sink 52, and has a high thermal conductivity. By providing the sheet 57, it is possible to insulate between the metal base 56 of the transistor and between the heat sink 52 and the metal base 56 of the transistor. Further, by providing the insulating heat transfer sheet 57 between the semiconductor discrete component 51 and the heat sink 52, the semiconductor discrete component 51 can be brought into close contact with the heat sink 52, and heat dissipation can be improved.

  Further, the structural material 2 includes a metal collar (female screw portion) 5 corresponding to the screw 4 (male screw portion) at a fastening portion with the screw 4. Thus, by providing the metal collar 5 at the fastening portion between the structural material 2 and the screw 4, a gap is formed between the structural material 2 and the screw 4 due to the difference in thermal expansion coefficient between the structural material 2 and the screw 4. Can be prevented.

Further, a screw hole (female screw portion) corresponding to the screw 4 is provided in the upper portion of the convex portion 3 of the heat sink 52.
Further, the semiconductor discrete component 51 and the structural material 2 may be bonded by an adhesive 6 (for example, epoxy). If the variation in the height of the semiconductor discrete component 51 is large, the semiconductor discrete component 51 including the adhesive 6 is adjusted by adjusting the amount (thickness) of the adhesive 6 used for each semiconductor discrete component 51. Can be made equal to each other (thickness D shown in FIG. 1). Thus, the upper surfaces of all the semiconductor discrete components 51 can be pressed by the structural material 2 with a uniform force. In addition, when the height of all the semiconductor discrete components 51 after being mounted on the heat sink 52 is substantially equal, the adhesive 6 may not be used.

  In this way, the entire upper surface of each semiconductor discrete component 51 can be pressed with a uniform force by the structural material 2, so that all the semiconductor discrete components 51 can be brought into close contact with the heat sink 52. As a result, it is possible to prevent any semiconductor discrete component 51 from overheating.

  Further, the plurality of semiconductor discrete components 51 can be fixed with one structural material 2 by fixing the structural material 2 and the convex portion 3 provided at the end of the heat sink 52 with the four screws 4. As a result, the semiconductor discrete components 51 can be brought closer to each other than the discrete semiconductor device 58 shown in FIG. 5B, so that the size of the discrete semiconductor device 1 can be reduced.

FIG. 2 is a diagram showing a discrete semiconductor device according to another embodiment of the present invention. In addition, the same code | symbol is attached | subjected about the same structure as FIG.
As shown in FIG. 2, in the discrete semiconductor device 7, a plurality of semiconductor discrete components 51 are pressed by the structural material 2, and the plurality of semiconductor discrete components 51 are fixed to a heat sink 52. This configuration is basically the same as that of the discrete semiconductor device 1 shown in FIG.

A feature of the discrete semiconductor device 7 shown in FIG. 2 is that a rib 8 and a metal plate 9 are provided inside the structural material 2 on the lower surface of the structural material 2.
FIG. 3 is a view of the rib 8 provided on the lower surface of the structural material 2 of the discrete semiconductor device 7 as viewed from above. In addition, the same code | symbol is attached | subjected about the same structure as FIG.

As shown in FIG. 3, the rib 8 is provided on the lower surface of the structural material 2 in a shape extending in the horizontal direction and the vertical direction on the same plane as the structural material 2 so as not to contact the semiconductor discrete component 51. The rib 8 may be provided on the upper surface of the semiconductor discrete component 51.
Thus, by providing the rib 8 in the structural material 2, the bending rigidity of the structural material 2 can be made high and intensity | strength can be raised.

FIG. 4 is a top view of the bus bar when the metal plate 9 in the structural member 2 of the discrete semiconductor device 7 is a bus bar. In addition, the same code | symbol is attached | subjected about the same structure as FIG.
The bus bar shown in FIG. 4 is, for example, a metal plate 9 in a discrete semiconductor device 7 including a transistor that constitutes an inverter of a three-phase motor, and includes an input (−) bus bar 10, an input (+) bus bar 11, and a U-phase bus bar 12. , V-phase bus bar 13 and W-phase bus bar 14. The main current terminal 15 (source / drain or emitter / collector) of the transistor is connected to each bus bar, and the control terminal 16 (gate or base) of the transistor is connected to the control circuit board.

  Thus, by providing the metal plate 9 in the structural material 2, the strength of the structural material 2 can be increased. Further, by using the metal plate 9 as a wiring for supplying power to the semiconductor discrete component 51, a space for the wiring can be omitted, and the discrete semiconductor device 7 can be miniaturized correspondingly. Further, the work of routing the wiring can be eliminated, and the manufacturing process of the discrete semiconductor device 7 can be facilitated.

In addition, this invention is not limited to the said embodiment, A various structure is employable in the range described in each claim. For example, the following configuration changes are possible.
(1) In the above embodiment, the structure material 2 is provided with the rib 8 and the metal plate 9, but the structure material 2 may be provided with only the rib 8, or the structure material 2 may be provided with only the metal plate 9. It is good also as a structure which provides.

(2) In the above embodiment, the corners of the structural material 2 and the corners of the heat sink 52 are fixed by the four screws 4, but the mounting position of the screws 4 and the number of the screws 4 are not limited to this configuration.
(3) In the above embodiment, the plurality of semiconductor discrete components 51 are fixed by one structural material 2, but the plurality of semiconductor discrete components 51 may be fixed by a plurality of structural materials 2.

(4) In the above-described embodiment, the structural material 2 and the heat sink 52 are fixed by the screw 4. However, the fixing member for fixing the structural material 2 and the heat sink 52 is not limited to the screw 4, and a clip, a rivet, or the like. But you can.
(5) In the above embodiment, in order to prevent a gap from being formed between the structural material 2 and the screw 4, the metal collar 5 is provided at the fastening portion between the structural material 2 and the screw 4. Instead of providing, the thickness of the structural material 2 at the fastening portion between the structural material 2 and the screw 4 may be thinned to be, for example, about 1 mm or less. Thereby, since the difference in coefficient of thermal expansion between the structural material 2 and the screw 4 can be reduced, it is possible to prevent a gap from being formed between the structural material 2 and the screw 4.

It is a figure which shows the discrete semiconductor device of embodiment of this invention. It is a figure which shows the discrete semiconductor device of other embodiment of this invention. It is the figure which looked at the rib provided in a structural material from the top. It is the figure which looked at the bus-bar in a structural material from the top. It is a figure which shows the existing discrete semiconductor device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Discrete semiconductor device 2 Structural material 3 Convex part 4 Screw 5 Metal color 6 Adhesive 7 Discrete semiconductor device 8 Rib 9 Metal plate 10 Input (-) bus bar 11 Input (+) bus bar 12 U phase bus bar 13 V phase bus bar 14 W phase Bus bar 15 Main current terminal 16 Control terminal 50 Discrete semiconductor device 51 Semiconductor discrete component 52 Heat sink 53 M3 screw 54 Water channel 55 Resin 56 Metal base 57 Insulating heat transfer sheet 58 Discrete semiconductor device 59 Clip 60 Clamp

Claims (8)

  The entire upper surface of the semiconductor discrete component provided above the heat sink via an insulating heat transfer sheet is pressed with a structural material, and the metal collar provided inside the structural material and the heat sink are fixed by a fixing member. Method for fixing semiconductor discrete parts. A method for fixing a semiconductor discrete component according to claim 1,
A method of fixing a semiconductor discrete component, wherein the structural material is provided with a rib. A method for fixing a semiconductor discrete component according to claim 1,
A method of fixing a semiconductor discrete component, wherein a metal plate is provided inside the structural material. A method for fixing a semiconductor discrete component according to claim 3,
The method of fixing a semiconductor discrete component, wherein the metal plate is a wiring for supplying electric power to the semiconductor discrete component. A heat sink,
A semiconductor discrete component provided above the heat sink;
An insulating heat transfer sheet that is provided between the heat sink and the semiconductor discrete component, transmits heat generated in the semiconductor discrete component to the heat sink, and is made of an insulating material;
A structure material for holding the entire upper surface of the semiconductor discrete component and fixing the semiconductor discrete component on the insulating heat transfer sheet;
A fixing member for fixing the heat sink and the structural material;
A metal collar provided at a fastening portion between the heat sink and the fixing member inside the structural material;
A discrete semiconductor device comprising: The discrete semiconductor device according to claim 5,
A discrete semiconductor device, wherein the structural material is provided with a rib. The discrete semiconductor device according to claim 5,
A discrete semiconductor device, wherein a metal plate is provided inside the structural material. The discrete semiconductor device according to claim 7,
The discrete semiconductor device, wherein the metal plate is a wiring for supplying electric power to the semiconductor discrete component.

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