JPS593580Y2 - Semiconductor chip support device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for supporting a semiconductor chip on a metal substrate, such as a hybrid IC, and more specifically, the present invention relates to a device for supporting a semiconductor chip on a metal substrate, such as a hybrid IC, and more specifically, a device for supporting a semiconductor chip on a metal substrate while maintaining good heat dissipation characteristics and electrical insulation characteristics. Regarding the structure to be attached to.

When attaching a power transistor chip to the metal substrate of a hybrid IC, it is necessary to electrically insulate the transistor chip from the metal substrate and to conduct the heat generated by the transistor chip to the metal substrate in a state with low thermal resistance. be.

For this reason, semiconductor chips have generally been attached using a structure as shown in FIG. 1 or 2.

First, referring to FIG. 1, the copper heat dissipation support 2 as a heat sink to which the semiconductor chip 1 is fixed is not directly bonded to the metal substrate 3 such as aluminum or iron, but is interposed with a ceramic plate 4 such as alumina or beryllia. In this state, it is bonded with solder 5.

According to this structure, it is possible to completely insulate and separate the semiconductor chip 1 by the ceramic plate 4, but it is impossible to make the ceramic plate 4 extremely thin. In FIG. 2, where the thermal resistance between the two parts cannot be made very small, the heat dissipation support 2 is bonded to the metal substrate 3 with an insulating epoxy resin layer 6.

According to this structure, it is possible to reduce the thermal resistance by making the epoxy resin layer 6 thinner, but there is a risk that a partial short circuit may occur due to the unevenness of the heat dissipation support 2 or the metal substrate 3.

Another problem is that epoxy resins are sensitive to heat.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a semiconductor chip support device that is capable of supporting a semiconductor chip on a metal substrate in a state with low thermal resistance and that also allows reliable mounting.

To achieve the above object, the present invention includes a metal substrate, an insulator including at least an insulating film disposed on the metal substrate, a heat dissipation support disposed on the insulator, and a heat dissipation support disposed on the heat dissipation support. The heat dissipation support is fixed to the metal substrate with a fixed semiconductor chip and a portion protruding from the metal substrate, and the heat dissipation support is pressed in the direction of the metal substrate by the protrusion portion. The present invention relates to a semiconductor chip support device that includes a fixed holding body formed to fixedly hold the heat dissipation support while maintaining electrical insulation with respect to the metal substrate.

According to the present invention, since the heat dissipating path having an insulating function and the part for fixing the chip and the heat dissipation support to the metal substrate are provided separately, the fixing part becomes substantially irrelevant to the thermal resistance. Thermal resistance can be reduced.

That is, an insulator made of an insulating film coated with non-volatile insulating oil or insulating grease is preferably interposed between the heat dissipation support and the metal substrate, but no solder or adhesive is interposed, and this portion is Thermal resistance is smaller than before.

The fixed holder for fixing the heat dissipation support to the metal substrate is
Since it is unrelated to thermal resistance, it is possible to design without considering thermal resistance, and it is possible to reliably achieve fixed retention.

In addition, since the fixed holding body is configured to press the heat dissipation support towards the metal substrate, it is possible to suppress an increase in thermal resistance of the insulator portion, and it is possible to achieve fixed holding relatively easily. I can do it.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 shows a hybrid I according to the first embodiment of the present invention.
3 shows a structure in which a semiconductor chip 12, such as a power transistor chip, is attached to a metal substrate 11 in FIG.

A major feature of this mounting structure is that the part that maintains electrical insulation and conducts heat is separated from the part that is fixed and held.

Therefore, no adhesive portion is provided between the lower surface of the copper heat dissipation support 13 to which the semiconductor chip 12 is fixed and the upper surface of the metal substrate 11, and only the insulator 14 is interposed.

The insulator 14 is protected from the insulating film 15 and the nonvolatile insulating silicone oil 16 coated on both sides of the insulating film 15.
Used only for insulation isolation.

Therefore, the thermal resistance in the insulator 14 is extremely small.

In order to fix the heat dissipation support 13 to the metal substrate 11, the heat dissipation support 13 is provided with a flange-like portion 17, and the upper surface of this flange-like portion 17 is fixed and held by a frame-shaped metal member through a synthetic resin insulator 18. It is pressed by the protruding portion 20 of the body 19.

One end portion 21 of the fixed holder 19 is fixed to the metal substrate 11 by welding, and a protruding portion 20 at the other end is bent and presses the flange-shaped portion 17 through the insulator 18.

Since the insulator 18 and the protruding portion 20 can be deformed by pressure, when the protruding portion 20 is pressed toward the metal substrate by a pressing device (not shown), the insulator 14 will be deformed by the heat dissipation support 13.
and in close contact with the metal substrate 11.

In this embodiment, as is clear from FIG. 4, the heat dissipation support 13 is formed in a cylindrical shape, so the fixed holder 19 is provided with a circular opening 22, and the heat dissipation support The lower part of body 13 is inserted.

The fixed holding body 19 can be formed extremely easily by pressing a metal plate, and the heat dissipation support 1
Before pressing 3, the protruding portion 20 adjacent to the opening 22 is formed to stand up a little more than in FIG.

Therefore, at the same time or after welding the one end portion 21 to the metal substrate 11, it is pressurized and deformed in the direction of the metal substrate 11, and the flange-shaped portion 17 of the heat dissipation support 13 is pressed in the direction of the metal substrate 11.

The semiconductor chip support structure as described above provides the following advantages.

(a) Since the heat dissipation support 13 to which the semiconductor chip 12 is fixed is not fixed to the metal substrate 11 by using the lower surface of the heat dissipation support 13, there is a gap between the heat dissipation support 13 and the metal substrate 11. It is only necessary to interpose a thin layer of insulating film 15 and insulating oil 16.

Therefore, the portion necessary for fixing becomes independent of thermal resistance, and the thermal resistance is significantly reduced.

(b) Since the fixed holding body 19 can be designed without regard to thermal resistance, a stable holding structure can be achieved.

(C') A flange-shaped portion 17 is provided on the heat dissipation support 13,
Since this is pressed and fixed by the protruding portion 20 of the fixed holder 19, the insulator 14 made of the insulating film 15 and the oil 16 is brought into close contact with the metal substrate 11 and the heat dissipation support 13, further reducing the thermal resistance. .

(d) Since the welding and processing deformation are constant without using adhesives or solders, it is possible to proceed with the work efficiently.

(e) Since the fixed holding body 19 is provided in its opening 22 in a state in which the lower part of the heat dissipation support body 13 is sealed, there is little possibility that the insulating oil 16 will leak out.

(f) Since the oil 16 is applied to the insulating film 15, not only is insulation separation more reliable, but also the thermal resistance is reduced due to improved adhesion.

Next, a second embodiment of the present invention will be described.

However, since the parts indicated by reference numerals 11 to 17 are substantially the same as the parts indicated by the same reference numerals in FIG. 3, the explanation thereof will be omitted.

In this embodiment, a recess 23 is provided in the metal substrate 11, into which the insulator 14 and the lower part of the heat dissipation support 13 are inserted.

In addition, the printed circuit board 1 is
Fixed holding is achieved by fixing 9a to the metal substrate 11.

For this reason, the printed circuit board 19a has an opening 22a.
is provided, and a protruding portion 20a is provided in the recess 23.

Further, in order to press the heat dissipation support 13 well with the protruding portion 20a, an elastic sheet 24 is disposed between the protruding portion 20a and the flange-like portion.

If configured as described above, the same advantages as the first embodiment can be obtained, and the printed circuit board 19a can be used as a fixed holder.
, the advantage is that the configuration of the device is simplified.

Next, FIG. 6 showing a third embodiment of the present invention will be described.

However, since the parts indicated by reference numerals 11 to 22 are substantially the same as those shown by the same reference numerals in FIG. 3, the explanation thereof will be omitted.

In this embodiment, the lower part of the heat dissipation support 13 is hemispherical, and the metal substrate 11 is provided with a semicircular depression 25.

Therefore, the stepped surface of the flange-shaped portion 17 is lower than the main surface of the metal substrate 11, and the protruding portion 20 of the fixed holder 19 presses against the flange-shaped portion 17 without rising above the surface of the metal substrate 11. There is.

In this embodiment, since the insulator 18 has elasticity,
This elastic deformation ensures good fixation.

According to this embodiment, in addition to obtaining the same advantages as the first embodiment, since the opposing area between the heat dissipation support 13 and the metal substrate 11 is increased, there is an advantage that the thermal resistance is further reduced.

Further, since the fixed holding body 19 may be a flat plate, handling becomes easy.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, but can be further modified.

For example, instead of the printed circuit board 19a in the embodiment shown in FIG. 5, a metallic rotating holder 19 as shown in FIGS. 3 and 6 may be used.

Furthermore, although silicone oil 16 is used in the embodiment, non-volatile insulating grease such as silicone grease may be applied to the insulating film 15 instead.

Alternatively, insulation may be performed using only the insulating film 15.

Alternatively, an insulating film impregnated with oil or the like may be used.

In the case of a completely sealed structure, the inside may be filled with oil 16.

Further, in the embodiment, transistors 1 to 1 are used as the semiconductor chip 12, but of course a diode or the like may be used.

Further, in FIGS. 3 and 6, the fixed holder 19 may be fixed to the substrate 11 with an adhesive.

Further, the fixed holding body 19 may be formed of a synthetic resin having insulating properties.

In addition, in the apparatus shown in FIG.
9 has a circular planar shape, but it may also be rectangular or the like.

Furthermore, a molybdenum, tungsten plate, or the like may be interposed between the semiconductor chip 12 and the heat dissipation support 13.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are cross-sectional views showing conventional semiconductor chip mounting structures, respectively. FIG. 3 is a sectional view of a semiconductor chip support device according to the first embodiment of the present invention. 4 is a plan view of the apparatus of FIG. 3; FIG. FIG. 5 is a sectional view of a semiconductor chip support device according to a second embodiment of the present invention. FIG. 6 is a sectional view of a semiconductor chip support device according to a third embodiment of the present invention. In the symbols used in the drawings, 11 is a metal substrate, 12 is a semiconductor chip, 13 is a heat dissipation support, 14 is an insulator, 15 is an insulating film, 16 is oil, 17 is a flange-like part, and 18 is an insulator. , 19 is a fixed holding body, 20 is a protrusion, 21 is one end, and 22 is an opening.

Claims (7)

[Scope of utility model registration request] (1) a metal substrate; an insulator including at least an insulating film disposed on the metal substrate; a heat dissipation support disposed on the insulator; a semiconductor chip fixed on the heat dissipation support; The metal substrate has a portion protruding from the metal substrate and is fixed to the metal substrate, and the protruding portion presses the heat dissipation support in the direction of the metal substrate to fix and hold the heat dissipation support, and the metal and a fixed holder formed to fixedly hold the heat dissipation support while maintaining electrical insulation from the substrate. (2) The semiconductor chip support device according to claim 1, wherein the insulator is composed of an insulating film and non-volatile insulating oil. (3) The semiconductor chip support device according to claim 1, wherein the insulator is made of an insulating film and an insulating grease. (4) The semiconductor according to claim 1, 2, or 3, wherein the heat dissipation support has a flange-shaped portion that is pressed by the protruding portion of the fixed holding body. Chip support device. (5) The fixed holding body is a metal frame formed in a frame shape so as to surround the heat dissipation support, one end of the metal frame is fixed to the metal substrate, and the other end of the metal frame is fixed to the metal substrate. The semiconductor chip support according to claim 1 or 2 or 3 or 4, wherein the semiconductor chip support is elastically engaged with the heat dissipation support via an insulator. Device. (6) The metal substrate has a recess into which the lower part of the heat dissipation support can be inserted. 6. The semiconductor chip support device according to item 5. (7) The fixed holder is a printed circuit board fixed to the metal substrate and has an opening through which the heat dissipation support can be inserted and a protruding portion for pressing the heat dissipation support. A semiconductor chip support device according to claim 6 of the utility model registration claim.