JP2002314035A - Power semiconductor module - Google Patents

Abstract

(57) [Problem] To provide a power semiconductor module provided with a terminal connection portion capable of electrically connecting an external wiring and an external connection terminal with high reliability. A semiconductor device, an external connection terminal electrically connected to an external wiring, a screw mechanism for securing a contact surface pressure between a conductor contact surface of the external wiring and the external terminal, An angle between the external wiring and the conductor contact surface of the external terminal and the propulsion direction of the screw mechanism of the power semiconductor module having a heat radiating plate for dissipating heat to an external heat radiating mechanism is 0 ° to 45 ° °.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an internal insulation type semiconductor module, and more particularly to a power semiconductor module suitable for a power conversion switching element.

[0002]

2. Description of the Related Art A power semiconductor module including a switching element and an IPM (Int) including a control circuit therein.
elligent Power Modules) have expanded their applications as semiconductor power switching devices such as IGBTs have increased in capacity and inverters have been used in home appliances. As a result, product applications in a wide range from small capacity to large capacity have been expanded. There is a strong demand for lower prices. In addition, as the applications have expanded, it has also become important to reduce the mounting area and to facilitate mounting and replacement. In such a power semiconductor module or IPM, since a mounted power semiconductor element generates a large amount of heat, it is made of a metal heat sink having good heat conductivity and a material having good heat conductivity and high electrical insulation. An insulating substrate, a conductive layer on which a circuit pattern is formed, and an external connection terminal connected to an external wiring are provided.

FIG. 7 shows a power semiconductor module according to the prior art. In this prior art power semiconductor module, as shown in FIG. 7, a resin insulating layer 102 serving as an insulating substrate is provided on one surface (upper surface in the figure) of an aluminum radiator plate 101, and a conductive layer is provided thereon. 103 is bonded to a predetermined position on the conductive layer 103 by soldering.
It is provided with a power semiconductor element 104 such as a GBT 104a and a diode 104b. In the conductive layer 103,
An external connection terminal 108 is provided as appropriate. Heat sink 101
The cooling fin 1103 is attached to the cooling fin 1103 with a bolt 113 to dissipate heat generated by the power semiconductor element 104. A thin metal wire 105 is connected to the conductive layer 103 on the resin insulating layer 102, further wired to an external connection terminal 108, placed in a case 106, and sealed with a resin 107. In this specification, a resin means a synthetic resin, that is, a plastic.

In a conventional power semiconductor module shown in FIG. 7, a nut 110 is inserted into a hole 109 provided in an upper portion of a case 106, and an external connection terminal 108 formed integrally with the case 106 is pulled out of the case 106 and bent. I have. The external connection terminal 108 and the external wiring 111 are electrically connected by tightening a bolt 112 b on the upper surface of the nut 110.

[0005] In the power semiconductor module of the prior art shown in FIG. 7, the external wiring 111 is arranged in parallel with the mounting surface of the heat sink 101. This is for facilitating attachment and replacement of the power semiconductor module. The bolts 113 for attaching the heat sink to the cooling fins are perpendicular to the mounting surface of the heat sink 101. In order to facilitate installation, all bolts are tightened in the same direction, and the bolts for mounting the heat sink and the bolts for mounting the external wiring and the external connection terminals have the same tightening direction. For this reason, the mounting surface of the heat sink and the external wiring are arranged in parallel.

In some cases, the power semiconductor module has the external wiring 111 arranged perpendicular to the mounting surface of the heat sink 101 as shown in FIG. In FIG. 8, the external wiring 1
11 is bent at an appropriate place to make the external wiring 111 parallel to the mounting surface of the heat sink 101,
And bolt 112b for connection. This is because the bolt 11 for attaching the external wiring 111 and the external connection terminal 108 is used.
2b and bolts 113 for attaching the radiator plate 101 to the cooling fins 1103 are tightened in the same direction to facilitate attachment.

[0007]

However, in the power semiconductor module of the prior art shown in FIG. 8, there is a difference in linear expansion coefficient between the external wiring and the power semiconductor module. Stress occurs at the terminal connection. Also, since the power semiconductor module is sandwiched between the bent external wiring and the cooling fin from above and below,
When replacing the power semiconductor module, it is necessary to remove external wiring or move the power semiconductor module in the left-right direction. In the case of moving, it is necessary to keep a large mounting area around the power semiconductor module.

[0008] An object of the present invention is to easily attach and replace the external wiring when the external wiring is arranged perpendicular to the mounting surface of the heat sink, and to electrically connect the external connection terminal and the external wiring with high reliability. It is to provide a power semiconductor module.

[0009]

A power semiconductor module according to the present invention comprises: a semiconductor element which generates heat when an electric current flows; an external connection terminal electrically connected to an external wiring;
A screw mechanism for securing a contact surface pressure between the external wiring and the conductor contact surface of the external terminal, and a heat radiating plate for dissipating heat generated by the semiconductor element; The conductor contact surface is a plane, and the propulsion direction of the conductor contact surface and the screw mechanism is 0 ° to 45 °.

FIG. 1 is a sectional view of a power semiconductor module according to the present invention. Bolt 112a for mounting external wiring 111 to external wiring 111 and external connection terminal 108 and heat sink
101 is arranged in parallel with a bolt 113 for attaching to the cooling fin 1103. External wiring 111 and external connection terminal 1
FIG. 2 shows an enlargement of the terminal connection portion 140 for connecting the 08.
In the power semiconductor module of the present invention, the contact surface of the external wiring 111 and the contact surface of the external connection terminal 108 are
, That is, perpendicular to the mounting surface of the heat sink. The contact surface of the external wiring 111 and the contact surface of the external terminal 108 are flat. When the bolt 112a in FIG. 2 is pushed in the direction A, a load P1 acts on the upper surface of the wedge-shaped block 202. The load P1 is decomposed into a load P2 and a load P3 by the wedge-shaped block, and the external wiring 111 and the external connection terminal 108 are pressurized by the action of the load P2 to secure a contact surface pressure.

In the terminal connecting portion 140 of the power semiconductor module according to the present invention, the tightening direction of the bolts 112a is the same as the bolt for attaching the heat sink to the cooling fins. In addition, the external wiring 111 of the power semiconductor module of the present invention
The contact surface between the power semiconductor module and the external connection terminal 108 is in a direction perpendicular to the mounting surface of the heat sink, and can be easily inserted, so that the power semiconductor module can be easily mounted and replaced.

The contact surface between the external wiring and the external connection terminal of the power semiconductor module according to the present invention is a flat surface. At least one of the external wiring and the external connection terminal is provided with a screw, and the screw surface is used as an electrical contact surface. The contact surface between the external wiring and the external connection terminal, the screw mechanism for securing the contact surface pressure, and the screw mechanism for attaching the heat sink are parallel to each other. Here, assuming that the screw surface is a contact surface, the screw surface has a smaller contact area in the case of the same inner diameter than a flat surface, so that the contact resistance is increased.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to the embodiments described below. In each drawing, the same reference numerals indicate the same components. (Embodiment 1) FIG. 1 is a sectional view of a power semiconductor module of the present embodiment. In FIG. 1, the power semiconductor module is provided with a resin insulating layer 102 serving as an insulating substrate on one surface (an upper surface in FIG. 1) of a heat radiating plate 101, and bonding a conductive layer 103 thereon. The power semiconductor element 104 is soldered at a predetermined position on the conductive layer 103. An external connection terminal 108 is appropriately provided on the conductive layer 103, and the heat radiating plate 101 is attached to the cooling fin 1103 by tightening the bolt 113 so that the power semiconductor element 10
4 dissipates heat. The external wiring 111 and the cooling fin 1103 are electrically insulated by an insulator 114. In addition,
The power semiconductor element is an IGBT, a power MOSFET.
Any of T may be used.

In this embodiment, the case 106 is adhered to the heat radiating plate 101 via the resin insulating layer 102. However, since the case 106 is made of PPS (polyphenylene sulfide) resin having high heat resistance, In addition, the case 106 can be bonded to the resin insulating layer 102 at the same time when the power semiconductor element 104 and the conductive layer 103 are joined by soldering. The conductive layer 1
03, the power semiconductor element 104, and a part of the external connection terminal 108 are sealed with a resin 107 having high thermal conductivity to complete a power semiconductor module. On the other hand, the external connection terminal 108 formed integrally with the case 106 is in contact with and electrically connected to the external wiring 111 at the terminal connection portion 140 on the outer side wall of the case 106.

FIG. 2 is a detailed sectional view of the terminal connecting portion 140. The terminal connection part 140 is provided with a wedge-shaped block 202 in the terminal connection part case 201, tightens the bolt 112a, and press-contacts the external connection terminal 108 and the external wiring 111 sandwiched between the wedge-shaped blocks 202, Make an electrical connection. In this embodiment, the connection between the external connection terminal 108 and the external wiring 111 is easy, and the adhesion between the external connection terminal 108 and the external wiring 111 is good. Here, terminal connection case 2
The material 01 and the wedge-shaped block 202 may be made of any material having a strength capable of withstanding the stress generated by bolt tightening, and may be steel, copper, a copper alloy or the like, and preferably copper or a copper alloy from the viewpoint of electric conductivity.

As shown in FIG. 2, in this embodiment, a through hole 204 is provided in the terminal connection case 201 so that the contact state between the external connection terminal 108 and the external wiring 111 can be checked.
The connection state at the time of installation can be easily managed.

(Embodiment 2) This embodiment is the same as Embodiment 1 except for the terminal connecting portion shown in FIG. In this embodiment, as shown in FIG. 3, an intermediate plate 205 made of a material harder or softer than the wedge-shaped block 202 is arranged between the bolt 112a and the wedge-shaped block 202 to reduce a bending load generated on the bolt 112a. Therefore, high reliability is obtained. In this embodiment, when the bolt 112a is pressed directly against the wedge-shaped block 202, the bolt tip 20
3 deforms the surface of the wedge-shaped block to form a depression, but it is difficult to form a depression in which an intermediate plate made of a material harder than the wedge-shaped block is arranged.
And the bending load of the bolt 112a is reduced. Note that the surface of the wedge-shaped block 202 may be quenched to increase the hardness. In this embodiment,
When the intermediate plate 205 made of a material softer than the wedge-shaped block is disposed, the intermediate plate itself is deformed and the wedge-shaped block 2 is formed.
02, the bending load of the bolt 112a can be reduced.

(Embodiment 3) This embodiment is the same as Embodiment 1 except for the terminal connecting portion shown in FIG. In this embodiment, one bolt is used as shown in FIG. The flat plate 206 is provided so as to contact the lower part of the bolt 112a,
a, the flat plate 206 simultaneously pushes the two wedge-shaped blocks 202, and the external connection terminal 108 and the external wiring 1
11 is brought into contact by pressing. The material of the flat plate 206 is the same material as the wedge-shaped block 202 or a harder material.

(Embodiment 4) This embodiment is the same as Embodiment 1 except for the terminal connection portion shown in FIG. In this embodiment, the wedge-shaped block and the bolt are integrated as shown in FIG. The external connection terminal 108 and the external wiring 111 are arranged between the side surface of the terminal connection case 201 and the wedge-shaped block 202, and the bolts 112a are tightened to make contact.
In the present embodiment, the size of the terminal connection portion and the number of parts can be reduced.

Embodiment 5 This embodiment is the same as Embodiment 1 except for the terminal connection shown in FIG. In this embodiment, as shown in FIG. 6, the external connection terminal and the external wiring were brought into contact with a metal clip. Fixed clip 207 and movable clip 20
8 is fixed by a pin 209 to such an extent that the movable clip 208 is movable. The movable clip 208 is provided with a bolt 112a, and although not shown, the fixed clip 207 is provided with a screw hole for screwing the bolt 112a. The movable clip 2 is tightened by tightening the bolt 112a.
08 can contact the external connection terminal 108 and the external wiring 111.

(Embodiment 6) In this embodiment, the external wiring 111 has a bend structure as shown in FIG. This bend part 14
1, the difference in the coefficient of linear expansion between the external wiring and the power semiconductor module relieves the stress generated by the temperature rise / fall during operation, so that the terminal connection is prevented from being damaged,
High reliability can be secured.

(Embodiment 7) In this embodiment, as shown in FIG. 10, the contact surface between the external connection terminal and the external wiring and the bolt 112a are
Make an angle θ1. θ1 is an angle between 0 ° and 45 °. In the present embodiment, the angle θ2 of the wedge-shaped block 202 is equal (θ1 = θ2), and the wedge-shaped block 202 is fitted with the terminal connection case 201, The movement other than the movement of the bolt 112a in the axial force direction can be restricted. Here, if θ1 is larger than 45 °, connection work of external wiring becomes difficult due to connection of a large number of power semiconductor modules. In this embodiment, the bolt 11
The displacement of the contact point between 2a and the wedge-shaped block 202 can be eliminated, and the wedge-shaped block 202 can be prevented from being deformed.

[0023]

According to the present invention, it is possible to provide a power semiconductor module having a highly reliable terminal connection structure that can be easily mounted and replaced when the external wiring is perpendicular to the mounting surface of the heat sink. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a semiconductor module according to a first embodiment.

FIG. 2 is a sectional view of a terminal connection structure of the semiconductor module according to the first embodiment;

FIG. 3 is a sectional view of a terminal connection structure of a semiconductor module according to a second embodiment.

FIG. 4 is a sectional view of a terminal connection structure of a semiconductor module according to a third embodiment;

FIG. 5 is a sectional view of a terminal connection structure of a semiconductor module according to a fourth embodiment.

FIG. 6 is a sectional view of a terminal connection structure of a semiconductor module according to a fifth embodiment.

FIG. 7 is a sectional view of a conventional power semiconductor module.

FIG. 8 is a sectional view of another conventional power semiconductor module.

FIG. 9 is a sectional view of a semiconductor module according to a sixth embodiment.

FIG. 10 is a sectional view of a terminal connection structure of a semiconductor module according to a seventh embodiment.

[Explanation of symbols]

101: heat sink, 102: resin insulating layer, 103: conductive layer, 104: power semiconductor element, 105: thin metal wire, 1
06 ... case, 107 ... resin sealing, 108 ... external connection terminal, 109 ... hole, 110 ... nut, 111 ... external wiring,
112 ... bolts for attaching external wiring and external connection terminals
113: bolts for attaching heat sinks and cooling fins, 114
... Insulator, 140 ... Terminal connection part, 201 ... Terminal connection part case, 202 ... Wedge-shaped block, 204 ... Through hole, 20
5 ... Intermediate plate, 206 ... Wedge-shaped block pressing flat plate, 2
07: fixed clamp, 208: movable clamp, 209: pin, 11
03 ... Cooling fins.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Bando 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture Inside the Electric Systems Division, Hitachi, Ltd. (72) Inventor Shigeo Amagi 7-1 Omikacho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi, Ltd. Hitachi Research Laboratories (72) Inventor Naofumi Tanie 502 Kandate-cho, Tsuchiura-city, Ibaraki Pref.

Claims (3)

[Claims] A semiconductor device; an external connection terminal electrically connected to an external wiring; a screw mechanism for securing a contact surface pressure between a conductor contact surface of the external wiring and the external connection terminal;
In a power semiconductor module including a heat radiating plate for dissipating heat generated by the semiconductor element to an external heat radiating mechanism, a conductor contact surface of the external wiring and the external terminal is a plane, and the conductor contact surface and the screw mechanism A power semiconductor module, wherein an angle between the propulsion direction and the propulsion direction is 0 ° to 45 °. 2. The power semiconductor module according to claim 1, wherein said semiconductor element is an IGBT. 3. A metal heat sink, an insulating substrate provided on one surface of the metal heat sink, and a conductive layer provided on the insulating substrate.
In a power semiconductor module including a plurality of semiconductor elements joined to the conductive layer, a case accommodating the semiconductor elements, and an external connection terminal formed integrally with the case, the external connection terminal and the external wiring are preferably They are connected by a terminal connecting portion provided on the case side wall portion, the terminal connecting portion has a wedge portion pressed by a screw mechanism, and the external connection terminal and the external wiring are pressed by the wedge portion. A power semiconductor module, characterized in that: