JP2011066281A - Heat generating device - Google Patents

Abstract

There is provided a heat generating device capable of improving the thermal conductivity between a heat radiating member and a heat sink and reducing the cost.
A heat generating device includes a semiconductor element, a heat sink that receives heat generated from the semiconductor element, dissipates heat, exposes a part of the package to the outside, and is sealed together with the semiconductor element by a package, A heat radiating member 7 is provided which is welded to an externally exposed portion of the heat sink 6 and radiates heat by receiving heat from the heat sink 6.
[Selection] Figure 3

Description

  The present invention relates to a heat generating device, and more particularly to a heat generating device such as a power module in which a chip element is sealed with a package.

  As a conventional heat generating device, for example, there is a power module that is mounted on an automobile or the like and includes a power transistor that requires relatively large power (for example, Patent Document 1).

  This type of heat generating device has a silicon chip and a heat sink and is attached to a heat sink.

  A silicon chip contains a semiconductor integrated circuit and is joined to a heat sink by solder.

  The heat radiating plate is joined to the heat sink via heat radiating grease, and is entirely formed of ceramics that is partially impregnated with a conductive member.

  With the above configuration, heat generated in the silicon chip is transmitted to the heat radiating plate through the solder, further transmitted from the heat radiating plate to the heat sink through the heat radiating grease, and dissipated from the heat sink to the outside.

JP 2001-135758 A

  However, according to the conventional heat generating device, since the heat radiation grease is interposed between the heat radiating plate and the heat sink, there is a problem that the thermal resistance increases and the thermal conductivity between the heat radiating plate and the heat sink decreases. In addition, there is a problem that the number of parts increases due to the presence of the heat dissipating grease, resulting in an increase in cost.

  Accordingly, an object of the present invention is to provide a heat generating device that can increase the thermal conductivity between the heat radiating member and the heat sink and can reduce the cost.

  In order to achieve the above object, the present invention provides the heat generating devices (1) to (3).

(1) A heat generating element, a heat sink that receives heat generated from the heat generating element, dissipates heat, exposes a part to the outside and is sealed with a package together with the heat generating element, and is welded to an externally exposed portion of the heat sink, A heat generating device comprising a heat radiating member that radiates heat by receiving heat from the heat sink.

(2) In the heat generating device according to (1), the heat radiating member has a through hole that positions the externally exposed portion of the heat sink in the opening surface.

(3) In the heat generating device according to (2), the heat radiating member is welded to the heat sink along the periphery of the heat sink side opening of the through hole.

  According to the present invention, the thermal conductivity between the heat radiating member and the heat sink can be enhanced, and the cost can be reduced.

The perspective view shown in order to demonstrate the heat generating device apparatus to which the heat generating device which concerns on embodiment of this invention was applied. AA sectional drawing of FIG. The perspective view shown in order to demonstrate the heat-emitting device which concerns on embodiment of this invention. The rear view shown in order to demonstrate the heat-emitting device which concerns on embodiment of this invention. (A) And (b) is the rear view and BB sectional drawing which show the principal part of FIG. (A) shows a rear view, and (b) shows a BB sectional view.

Embodiment
(Overall configuration of heat generating device)
FIG. 1 shows the entire heat generating device. FIG. 2 shows the back side of the heat generating device. As shown in FIG. 1, the heat generating device apparatus 1 includes a connector 2 and a heat generating device 3, and is mounted on a printed wiring board 4 (shown in FIG. 2) as a circuit board.

(Configuration of connector 2)
As shown in FIG. 1, the connector 2 includes connector terminals 20 to 22 for external connection and a connector housing 23 that holds these connector terminals 20 to 22.

  The connector terminal 20 includes a collector terminal side connection portion 20a connected to a collector terminal 10 (described later) of the heat generating device 3 and an external connection portion 20b detachably connected to an external connection terminal (not shown). Is integrated. As a material of the connector terminal 20, for example, a conductive material such as brass or phosphor bronze is used.

  The connector terminal 21 includes a base side connection portion 21a connected to a base terminal 11 (described later) of the heat generating device 3 and an external connection portion 21b detachably connected to an external connection terminal (not shown). The connector housing 23 is integrated in parallel. As the material of the connector terminal 21, the same material as that of the connector terminal 20 is used.

  The connector terminal 22 includes an emitter terminal side connection portion 22a connected to an emitter terminal 12 (described later) of the heat generating device 3 and an external connection portion 22b detachably connected to an external connection terminal (not shown). 20 is integrated with the connector housing 23 in parallel.

  The entire connector housing 23 is formed of an engineering plastic such as PBT (polybutylene terephthalate) resin. On one side of the connector housing 23, a first accommodation space 23a for accommodating the external connection portions 20b to 22b of the connector terminals 20 to 22 is provided inside. On the other side of the connector housing 23, a second housing space 23b for housing the heat generating device 3 and a part of the second housing space 23a are formed so that the horizontal portion 10b (described later) of the connector terminal 10 and the connector terminal 21 A terminal block 23c on which the base terminal side connecting portion 21a and the emitter terminal side connecting portion 22a of the connector terminal 22 are placed is provided.

  As shown in FIG. 2, the printed wiring board 4 is formed of a base member having a circuit pattern (not shown). As the base member of the printed wiring board 4, for example, an insulating member such as ceramic or epoxy resin is used.

(Configuration of heat generating device 3)
FIG. 3 shows the entire heat generating device. FIG. 4 shows the back side of the heat generating device. FIGS. 5A and 5B show the main part of the heat generating device. As shown in FIG. 3, the heat generating device 3 includes a power module as a power semiconductor device such as a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor) having a semiconductor element 5, a heat sink 6 and a heat radiating member 7, and a power transistor. It is connected to the connector 2 and the printed wiring board 4 (both shown in FIG. 2) and is housed in the second housing space 23bd of the connector housing 23 (shown in FIG. 1). The heat generating device 3 is integrated with the connector housing 23 together with the connector terminals 20 to 22 (shown in FIG. 1) by insert molding.

  The heat generating device 3 and the connector housing 23 are integrated by welding the connector terminals 20 to 22 (shown in FIG. 2) of the connector 2 to the collector terminal 10, the base terminal 11 and the emitter terminal 12 of the heat generating device 3, respectively. After being placed in the mold, for example, an epoxy resin for forming the connector housing is injected and solidified in a molten state. At this time, since the connecting portion of the terminal or the like is welded, it is not melted by pouring the epoxy resin into the mold.

  As shown in FIGS. 3 and 4, the semiconductor element 5 is a heating element containing a semiconductor integrated circuit (not shown), is mounted on the collector electrode conductor plate 8, and is sealed by a package 9. . As a material of the package 9, for example, a mold material mainly composed of a thermosetting resin such as an epoxy resin is used.

  The collector electrode conductor plate 8 has a mounting portion 8a on which a plurality of semiconductor elements 5 are mounted, is sealed by a package 9, and is entirely formed of a material made of a copper-based metal such as brass. The collector electrode conductor plate 8 is integrally provided with a collector terminal 10 for external connection with a part thereof exposed to the outside. A base terminal 11 is disposed on one side of the collector terminal 10 and an emitter terminal 12 is disposed on the other side.

  The collector terminal 10 has a vertical portion 10 a rising from the surface thereof, and a horizontal portion 10 b placed on a terminal block 23 c (shown in FIG. 2) of the connector housing 23, and is connected to the collector terminal side connection portion 20 a of the connector terminal 20. Welded.

  The base terminal 11 is placed on a terminal block 23c (shown in FIG. 2) of the connector housing 23 and welded to a base terminal side connection portion 21a (shown in FIG. 2) of the connector terminal 21. The base terminal 11 is connected to the semiconductor element 5 via a bonding wire 13 such as aluminum (Al).

  The emitter terminal 12 is placed on a terminal block 23c (shown in FIG. 2) of the connector housing 23 and welded to the emitter terminal side connection portion 22a (shown in FIG. 2) of the connector terminal 22. The emitter terminal 12 is connected to the semiconductor element 5 via a bonding wire 13.

(Configuration of heat sink 6)
As shown in FIG. 4, the heat sink 6 includes a heat radiating portion 6 a and a connecting portion 6 b, and is provided integrally with the collector electrode conductor plate 8, and is entirely formed by a planar substantially T-shaped plate member. The thickness of the heat sink 6 is set to be larger than the thickness of the collector electrode conductor plate 8.

The outer edge of the heat dissipating part 6a is fillet welded to the heat dissipating member 7, for example, by laser light. Thereby, continuity is acquired in the joining location of the heat sink 6 and the heat radiating member 7, and thermal resistance can be reduced. In addition, since no heat dissipation grease or the like is interposed between the heat sink 6 and the heat dissipation member 7 as in the prior art, the number of components can be reduced. For fillet welding, for example, a CO ₂ laser or a YAG laser is used. The heat radiating part 3 a is configured to receive heat generated from the plurality of semiconductor elements 5 and radiate heat, and to transmit heat from the plurality of semiconductors 5 to the heat radiating member 7.

  The connecting portion 6b has a heat radiating function and a heat transfer function in the same manner as the heat radiating portion 6a, is partially exposed to the outside and sealed by the package 9, and is integrally formed with the heat radiating portion 6a. The connecting portion 6 is configured to connect the heat sink 6 to the collector electrode conductor plate 8.

(Configuration of heat dissipation member 7)
As shown in FIG. 4, the heat dissipating member 7 has a heat dissipating part 6 a as an externally exposed part of the heat sink 6 and a through hole 7 a that positions a part of the connecting part 6 b in the opening surface, and contacts the back surface of the heat sink 6. The whole is formed of a rectangular plate made of a copper-based metal such as brass. Further, as shown in FIGS. 5A and 5B, the heat radiating member 7 is irradiated with laser light L along the periphery of the heat sink side opening of the through hole 7 a and is welded to the heat sink 6, for example, by fillet welding. Thereby, continuity is acquired in the joining location of the heat sink 6 and the heat radiating member 7, and thermal resistance can be reduced. In addition, since no heat dissipation grease or the like is interposed between the heat sink 6 and the heat dissipation member 7 as in the prior art, the number of components can be reduced. The thickness of the heat radiating member 7 is set to a dimension of about 0.6 to 2 mm. The heat radiating member 7 may be configured to be connected to a heat conduction path (not shown).

  In the heat generating device apparatus 1 configured as described above, when the semiconductor element 5 generates heat by use, heat from the plurality of semiconductor elements 5 is transmitted to the heat sink 6 through the collector electrode conductor plate 8. At this time, part of the heat transmitted to the heat sink 6 is radiated to the outside from the heat radiating portion 6a and from the heat radiating portion 6a and the connecting portion 6b through the through holes 4a. Furthermore, heat from the semiconductor element 5 is transmitted from the heat sink 6 to the heat radiating member 7 and is radiated from the heat radiating member 7 to the surroundings.

[Effect of the embodiment]
According to the embodiment described above, the following effects can be obtained.

(1) The thermal resistance between the heat sink 6 and the heat radiating member 7 can be reduced to increase the thermal conductivity.

(2) Since no heat dissipating grease or the like is interposed between the heat sink 6 and the heat dissipating member 7 as in the prior art, the number of parts of the heat generating device 3 can be reduced, reducing the cost and reducing the size of the entire device. Can be planned.

(3) Since the connector 2 and the heat generating device 3 are integrated, the number of components of the heat generating device device 1 can be reduced, and the overall size of the device can be reduced.

(4) Since the assembly of the connector 2 and the heat generating device 3 to the printed wiring board 4 can be performed at once, the number of assembling steps at the time of assembling the components can be reduced, and the assembling work of the components can be simplified.

  As mentioned above, although the heat generating device of this invention was demonstrated based on said embodiment, this invention is not limited to said embodiment, It implements in a various aspect in the range which does not deviate from the summary. For example, the following modifications are possible.

(1) Although the case where the heat generating device 3 is a power module including a power MOSFET and a power transistor has been described in the above embodiment, the present invention is not limited thereto, and includes, for example, an IGBT (Insulated Gate Bipolar Transistor). It may be a heat generating device.

(2) Although the case where the number of the through holes 7a of the heat dissipation member 7 is single has been described in the above embodiment, the present invention is not limited to this, and a plurality of through holes may be used. It is set in consideration of the heat transfer area of the heat sink with respect to the heat radiating member and the mounting strength.

  DESCRIPTION OF SYMBOLS 1 ... Heat generating device apparatus, 2 ... Connector, 20 ... Connector terminal, 20a ... Collector terminal side connection part, 20b ... External connection part, 21 ... Connector terminal, 21a ... Base terminal side connection part, 21b ... External connection part, 22 ... Connector terminal, 22a ... Emitter terminal side connection part, 22b ... External connection part, 23 ... Connector housing, 23a ... First accommodation space, 23b ... Second accommodation space, 23c ... Terminal block, 3 ... Heat generating device, 4 ... Print wiring Plate 5, semiconductor element 6, heat sink 6 a heat radiating portion 6 b linking portion 7 heat radiating member 7 a through hole 8 collector electrode conductor plate 9 package 10 collector terminal 10 a vertical Part, 10b ... horizontal part, 11 ... base terminal, 12 ... emitter terminal

Claims (3)

A heating element;
A heat sink that receives heat generated from the heat generating element and dissipates heat, and a part is exposed to the outside and is sealed together with the heat generating element by a package;
A heat generating device comprising: a heat radiating member that is welded to an externally exposed portion of the heat sink and receives heat from the heat sink to dissipate heat.   2. The heat generating device according to claim 1, wherein the heat radiating member has a through hole that positions an externally exposed portion of the heat sink in an opening surface.   The heat generating device according to claim 2, wherein the heat radiating member is welded to the heat sink along a heat sink side opening peripheral edge of the through hole.

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