JPS6079759A - Insulating type semiconductor device - Google Patents

Abstract

PURPOSE:To expose only the bottom of a semiconductor chip support plate and surround the support plate with a resin body, and to coat the support plate and the bottom of the resin body with an insulating layer consisting of an elastomer layer and to fix the support plate and the resin body easily onto a cooling body by a fitting hole penetrating the resin body and the insulating layer. CONSTITUTION:A semiconductor chip 1 is fastened onto a metallic support plate 2 by a collector surface for the chip. A base electrode or an emitter electrode on the upper surface of the chip 1 is each connected to a terminal 5 fixed to the support plate 2 through an insulating piece 4 by a lead wire 3. The fringe section of the support plate 2 is buried to the lower section of a resin vessel 6, and the bottom of the vessel 6 and the bottom of the support plate 2 are formed in the same plane. The inside of the vessel 6 is filled with a case resin 7 sealing the chip 1. An insulating foil 8 is bonded with the bottoms of the vessel 6 and the support plate 2 by a rubber adhesive layer 9. A fitting hole 10 penetrating the vessel 6, the insulating foil 8 and the adhesive material layer 9 is formed, and the vessel 6, the support plate 2, the insulating foil 8 and the adhesive material layer 9 are mounted to a cooling body made of a metal by a screw.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to an insulated semiconductor device in which the surface of a semiconductor chip support plate, to which a collector surface of a transistor is fixed, for example, is covered with an insulating layer.

[Prior art and its problems]

When a semiconductor device with a semiconductor chip support plate made of metal exposed on the surface is insulated and fixed onto a cooling body also made of metal, an insulating plate such as a mica plate must be interposed. In order to save such trouble, for example, a so-called full-pack type semiconductor device is known in which the cooling body mounting portion of the semiconductor chip support plate of the JEDBCTO220 type is thinly coated with a sealing resin by transfer molding. It is difficult to obtain good heat transferable contact over the entire surface with the cooling body. Even if filler is dripped into the gap between the contact surfaces, it will flow out during long-term use, causing an increase in the thermal resistance between the semiconductor device and the cooling body. Furthermore, it is difficult to manufacture a large full-pack type semiconductor device.

[Purpose of the invention]

It is an object of the present invention to overcome this drawback and to provide an insulated semiconductor device that can be attached to a heat sink so as to contact the heat sink over a large area and to obtain good heat transfer.

[Key points of the invention]

A semiconductor device according to the present invention includes a layer made of an elastomer that forms the same plane as the bottom surface of a semiconductor chip support plate made of metal and a bottom surface of a resin body surrounding the support plate and the semiconductor chip, and covers the entire surface of the bottom surface. The above object is achieved by coating with an insulating layer and providing through holes perpendicular to the bottom surface of the resin body and the insulating layer. The elastomer is an adhesive and is preferably interposed as an adhesive layer between the insulating foil, the semiconductor chip support plate, and the bottom surface of the resin body, or is preferably bonded to the entire bottom surface to form an insulating layer by itself.

[Embodiments of the invention]

FIG. 1 shows an embodiment of the invention, in which a semiconductor chip, for example a transistor chip 1, is fixed on a metal support plate 2 by its collector surface. The base electrode or emitter electrode on the top surface of the chip 1 is connected to the support plate 2 by a lead wire 3.
are respectively connected to terminals 5 fixed via insulating pieces 4. The peripheral edge of the support plate 2 is embedded in the lower part of the resin container 6, and the bottom surface of the support plate 2 with the bottom of the container 6 is on the same plane. The inside of the container 6 is filled with a molding resin 7 for sealing the chip 1. An insulating foil 8 such as a polyester film is placed on the bottom of the container 6 and the support plate 2.
are adhered by a rubber adhesive layer 9. Furthermore, container 6
A mounting hole 10 is provided which penetrates the insulation foil 8 and the adhesive layer 9. This semiconductor device can be easily attached to a cooling body made of metal using screws inserted into the holes 10. In that case, an elastic adhesive R is attached to the bottom surface of the device.
9 exists, so that it comes into close contact with the cooling body and good heat transfer properties can be obtained. In addition, expansion due to temperature fluctuations during use of semiconductor devices,
Since the elastic adhesive layer and insulating foil follow the shrinkage, the thermal resistance between the cooling body is less likely to increase. It can also be configured as is.

In the above embodiment, the resin body consists of the resin container 6 and the casting resin 7, but they may be integrally formed by transfer molding. Further, the number of semiconductor chips is not limited to one, and a plurality of chips may be fixed on a common support plate in a conductive or insulated manner.

〔Effect of the invention〕

The present invention includes a semiconductor chip support plate made of metal of a semiconductor device, which is surrounded by a resin body with only the bottom surface exposed, and the bottom surfaces of the support plate and the resin body are covered with an insulating layer including a layer made of elastomer, and the resin body For mounting through the insulation layer, a hole is provided, and the mounting can be easily fixed on the heat sink using a mounting screw inserted into the hole, and the elasticity of the layer made of elastomer allows the insulated semiconductor device and the heat sink to be connected easily. The close contact between the semiconductor devices allows for good heat dissipation of the semiconductor device, and furthermore, even when the temperature fluctuates during use, there is no increase in thermal resistance, making it possible to operate the semiconductor device with high reliability, which is extremely effective.

[Brief explanation of drawings]

FIG. 1 is a cutaway perspective view of one embodiment of the present invention. 111. Semiconductor chip, 2... Support plate, 6... Resin container, 7... Casting resin, 8... Insulating foil, 9... Adhesive layer.

Claims (1)

[Claims] 1) The bottom surface of a semiconductor chip support plate made of metal and the bottom surface of a resin body surrounding the support plate and the semiconductor chip are formed on the same plane, and the bottom surface includes a layer made of an elastomer covering the entire surface. 1. An insulated semiconductor device covered with an insulating layer, the resin body and the insulating layer having a through hole perpendicular to the bottom surface thereof. 2)/l? 2. The insulated semiconductor device according to claim 1, wherein the elastomer is an adhesive for bonding between the insulating foil, the semiconductor chip support plate, and the bottom surface of the resin body. 3) An insulated semiconductor device according to claim 1, wherein the insulating layer is made of only an elastomer adhesive.