JP2000164797A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an insulating board from floating so as to restrain a semiconductor device from increasing in heat resistance, where an insulating board is mounted on a fin via grease in the semiconductor device. SOLUTION: A semiconductor device is composed of a thin-walled insulating board 21 equipped with a metal circuit 21a formed on its surface layer and mounted with a semiconductor chip 1 on the metal circuit 21a, a terminal block 7 provided with an outer connection terminal for connecting the metal circuit 21a to the outside, and an outer case 11 formed covering the periphery of the insulating board 21 and surrounding the terminal block 7, where the insulating board 21 is attached directly to a heat-radiating body to dissipate heat. The outer case 11 is equipped with a press member 20a, which presses down nearly the center of the insulating board 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly to a modular semiconductor device having improved cooling performance.

[0002]

2. Description of the Related Art The structure of a conventional semiconductor device is shown in FIGS.

FIG. 7A is a plan view of a conventional semiconductor device, FIG. 7B is a front view thereof, and FIG. 8 is a partial sectional view.

In these figures, reference numeral 1 denotes a semiconductor chip on which a semiconductor circuit including switching transistors and the like is formed, 2 denotes an insulating substrate on which the semiconductor chip 1 is mounted, and a lower surface has a metal for soldering to a metal substrate described later. Layers are applied. 2a is a metal circuit formed on the insulating substrate 2, 3 is a metal substrate, and the metal substrate 3 is the insulating substrate 2
And soldering. 4 is an outer case, 5 is a terminal block, 6 is a main current electrode, and 7 is a control electrode.
The main current electrode 6 and the control current electrode 7 are arranged on the terminal block 5. Reference numeral 8 denotes a metal wire for electrically connecting the semiconductor chip 1 and the metal circuit 2a.

FIG. 9A is a plan view of the outer casing, and FIG. 9B is a sectional view thereof.

FIG. 10A is a view showing a state in which the semiconductor chip 1 is mounted on the insulating substrate 2 and connected by metal wires 8. FIG. 10B is a view showing a state in which the insulating substrate shown in FIG. Substrate 3
FIG. 6 is a view showing a state where the sheet is adhered to a sheet.

In these figures, the main current electrode 6
The control electrode 7 is connected to the semiconductor chip 1 via the metal circuit 2a and the metal wire 8.

9 is an adhesive for attaching the outer casing 4 to the metal substrate 3, 10 is a gel-like filler for filling and solidifying the semiconductor chip 1, the metal circuit 2 a, the wires 8, etc. formed on the insulating substrate 2, 11 is a gel-like filler An epoxy resin further filled on the filler 10. The epoxy resin 11 is a gel-like filler 10
Is filled with a liquid epoxy resin 11 and is cured by heating.

FIG. 11 is a view showing a state in which the conventional semiconductor device is mounted on a fin serving as a heat radiator.

In FIG. 1, reference numeral 12 denotes grease having good thermal conductivity, and reference numeral 13 denotes a radiation fin. Grease having good thermal conductivity is applied between the metal substrate 3 and the heat radiation fins 13 of the semiconductor device to secure good heat radiation.

[0011]

In the above-mentioned conventional semiconductor device, the metal substrate 3 and the insulating substrate 2 are joined by solder or the like. For this reason, a step of bonding by soldering or the like is necessary, and the assembling requires a lot of man-hours. Further, the upper and lower materials of the solder joint are a metal substrate and an insulating substrate, and their linear expansion coefficients are different from each other, which causes a problem of thermal fatigue based on the difference in the linear expansion coefficient.

As a method of avoiding the problem of thermal fatigue, it is conceivable to attach an insulating substrate to the fins 13 directly via grease without using the metal substrate 3.

However, if the metal substrate is removed with the conventional structure, the insulating substrate 2 is thin and has low rigidity. Therefore, when the insulating substrate 2 is attached to the fins 13 via the grease 12, The grease at the center cannot be sufficiently discharged, and the center of the insulating substrate 2 rises. Therefore, the thermal resistance between the fin and the insulating substrate at the center of the insulating substrate increases.

The present invention has been made in view of the above-mentioned various problems, and in a semiconductor device having a structure in which a metal substrate 3 is removed, when an insulating substrate is attached to fins via grease, floating of the insulating substrate is prevented. Thus, a semiconductor device capable of preventing an increase in thermal resistance is provided.

[0015]

The present invention employs the following means in order to solve the above-mentioned problems.

A thin insulating substrate having a metal circuit formed on a surface layer and a semiconductor chip mounted on the metal circuit; a terminal block having external connection terminals for connecting the metal circuit to the outside; A semiconductor device, comprising: an outer case attached to the outer periphery and formed so as to surround the terminal block, wherein the semiconductor device radiates heat by directly attaching the insulating substrate to a radiator, wherein the outer case is the insulating substrate. And a pressing member that presses a substantially central portion of the light emitting device.

Further, in the semiconductor device, the pressing member is a rib formed so as to protrude toward the insulating substrate over the outer casing.

Further, in the semiconductor device, the pressing member includes a pressing force adjusting means for adjusting the pressing force.

Further, in the semiconductor device, the pressing force adjusting means is a screw member formed so as to be adjustable from the outside after assembling the semiconductor device.

Further, in the semiconductor device, the pressing force adjusting means includes an elastic member inserted between the rib and the screw member.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a partial sectional view of the semiconductor device according to the present embodiment, FIG. 2 is a view showing an outer case, FIG. 2A is a plan view thereof, and FIG. 2B is a sectional view thereof. FIG. 3 is a diagram showing a state in which a semiconductor chip is mounted on an insulating substrate and connected by metal wires.

In these figures, 20 is an outer case,
20a is a rib formed integrally with the outer case 20,
b denotes an adhesive, 21 denotes an insulating substrate, and 21a denotes a metal circuit formed on the insulating substrate 21. In the drawings, the same reference numerals are given to the same portions as those described as the conventional example in FIGS.

In this embodiment, as shown in FIG. 3, the semiconductor chip 1 is mounted on the insulating substrate 21 on which the metal circuit 21a is formed, and the metal circuit 21a and the semiconductor chip 1 are connected by the metal wires 8. .

Next, the outer casing 20 shown in FIG. 2 is assembled to the assembly of the insulating substrate 21 shown in FIG.

At the time of assembling, an outer case is attached to the outer periphery of the insulating substrate 21 with an adhesive 20b as shown in FIG.

The main current electrode 6 and the control electrode 7
Is assembled, and the metal wire 8 is connected to the main current electrode 6 or the control current electrode 7.
The electrodes 6 and 7 may be directly connected to the semiconductor chip 1 via a metal wire. Further, the connection block 5 may be formed integrally with the outer case 20.

Next, the gel filler 10 is injected and solidified.
Further, liquid epoxy resin 11 is injected, and cured by heating.
The assembly of the semiconductor device is completed.

In the present embodiment, the ribs 20a formed integrally with the outer casing 20 press the insulating substrate 21, so that when the insulating substrate 21 is attached to fins (not shown) via grease, the rising of the insulating substrate 21 is prevented. This can prevent the thermal resistance from increasing.

Next, a second embodiment of the present invention will be described with reference to FIGS.

FIG. 4 is a plan view of the semiconductor device according to the present embodiment, FIG. 5 is a view showing an outer case according to the present embodiment, FIG. 5 (a) is a plan view thereof, and FIG. It is sectional drawing.

In the figure, 22 is an outer case, 22a is a screw seat formed in the outer case, 23 is a screw fitted to the screw seat 22a, 24 is a convex rib forming a pressing member, and the convex rib 24 is It is slidably held along the outer casing case 22. In the drawings, the same reference numerals are given to the same portions as those described as the conventional example in FIGS. 7 to 11, and the description thereof will be omitted.

In this embodiment, the convex rib constituting the pressing member is formed separately from the outer casing 22.
The outer case 22 has a screw seat 22a, and a pilot hole is formed in the screw seat. The screw 23 that fits into the pilot hole is a self-tapping screw. The screw 23 is fitted into the screw seat 22a, the screw 23 is rotated, and the convex rib is pressed by the tip of the screw 23. The pressing force applied to the substantially central portion of the insulating substrate can be adjusted by the rib.

Next, a third embodiment of the present invention will be described with reference to FIG.

FIG. 6 is a view showing an outer casing according to the present embodiment, in which an elastic member such as a coil spring is inserted between the convex rib and the screw in the above embodiment.

In the figure, 25 is an outer case, 25a is a screw seat, 26 is a screw fitted to the screw seat 25a, 27 is a convex rib forming a pressing member, and the convex rib 27 extends along the outer case 22. Slidably held. Reference numeral 28 denotes an elastic member such as a coil spring, which elastically presses the convex rib 27.

Also in the case of the present embodiment, the screw 26 is
5a, the screw 26 is rotated, and the convex rib 27 is pressed by the tip of the screw 26 via the elastic member 28, whereby the pressing force by the rib can be adjusted.

In the second and third embodiments, even after assembling the semiconductor device, or after applying grease and attaching to the fin, the screw 23 or 26 is rotated to press the insulating substrate. Can be adjusted, so that a heavy load is not applied to the insulating substrate, and a highly reliable semiconductor device can be obtained.

[0039]

As described above, according to the present invention, in a semiconductor device having a structure in which the metal substrate 3 is removed, when the insulating substrate is attached to the fins via grease, the insulating substrate is prevented from floating and the thermal resistance is reduced. Can be prevented from increasing.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a view showing an outer case of the semiconductor device according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a state in which a semiconductor chip is mounted on an insulating substrate and connected by metal wires.

FIG. 4 is a plan view of a semiconductor device according to a second embodiment of the present invention.

FIG. 5 is a view showing an outer case according to a second embodiment of the present invention.

FIG. 6 is a view showing an outer case according to a third embodiment of the present invention.

FIG. 7 is a diagram showing a conventional semiconductor device.

FIG. 8 is a partial cross-sectional view of a conventional semiconductor device.

FIG. 9 is a view showing an outer case according to a conventional semiconductor device.

FIG. 10 is a diagram showing a state where a semiconductor chip is mounted on an insulating substrate.

FIG. 11 is a view showing a state in which a conventional semiconductor device is attached to a radiation fin.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor chip 5 Terminal block 6 Main current electrode 7 Control current electrode 8 Metal wire 10 Gel filling 11 Epoxy resin 20, 22, 25 Outer case 20a Rib 20b Adhesive 21 Insulating substrate 21a Metal circuit 22a, 25a Screw Seat 23, 26 Self-tapping screw 24, 27 Convex rib 28 Elastic member

Claims (5)

[Claims] 1. A thin insulating substrate having a metal circuit formed on a surface layer and a semiconductor chip mounted on the metal circuit; a terminal block having external connection terminals for connecting the metal circuit to the outside; A semiconductor device that is attached to the outer periphery of the substrate and formed so as to surround the terminal block, wherein the semiconductor device radiates heat by directly attaching the insulating substrate to a radiator; A semiconductor device comprising a pressing member for pressing a substantially central portion of an insulating substrate. 2. The semiconductor device according to claim 1, wherein the pressing member is a rib formed so as to protrude toward the insulating substrate across the outer casing. 3. The semiconductor device according to claim 1, wherein the pressing member includes a pressing force adjusting unit that adjusts a pressing force of the pressing member. 4. The semiconductor device according to claim 3, wherein the pressing force adjusting means is a screw member formed so as to be adjustable from the outside after assembling the semiconductor device. 5. The semiconductor device according to claim 4, wherein said pressing force adjusting means includes an elastic member inserted between said rib and said screw member.