JPH04273155A - Manufacture of hybrid integrated circuit for power service - Google Patents

Abstract

PURPOSE:To obtain a manufacturing method for power hybrid integrated circuit which cuts down heat history for a semiconductor power device and prevents characteristic deterioration. CONSTITUTION:A wiring board 2 is mounted on a heat dissipation board 1 wherein a soldering layer 4 is formed on a metallized layer 3 on both sides of the wiring board 2. A metal disk 5 is further mounted on the soldering layer. A semiconductor power device 7 is further integrated thereon by way of a sheet-shaped solder piece 6. Then, by a single reflow process, the soldering layers 4 and 6 are molten thereon in one lot in a reducing atmosphere so that the heat dissipation board 1, the wiring board 2, and the semiconductor power device 7 may be sealed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a hybrid integrated circuit, and more particularly to a method for manufacturing a power hybrid integrated circuit.

0002

[Prior Art] A conventional method for manufacturing a power hybrid integrated circuit, particularly an integrated circuit in which a power transistor is mounted on an insulating substrate and then mounted on a heat dissipating substrate, is first shown in FIG.
As shown in (a), a sheet-shaped solder piece 6 having a melting point of about 240°C is soldered onto a metal disk 5 whose surface is gold-plated on a copper material on a heater heated to 280°C to 300°C. Piece 6 is melted and power transistor 7 is fixed. Next, as shown in FIG. 2(b), a solder layer 4 is formed on the metallized layer 3 formed on the top of the insulating wiring board 2 made of alumina ceramics, etc. In the process, the metal disk 5 on which the power transistor 7 is mounted is melted and fixed by the solder layer 4. Thereafter, as shown in FIG. 2(c), the insulating wiring board 2 and the heat dissipating base 1 are bonded together with an adhesive layer 8.

0003

[Problems to be Solved by the Invention] In the conventional manufacturing method of power hybrid integrated circuits, in order to mount a semiconductor power device, two or more solder melting steps, that is, a step of applying high temperature are performed. Therefore, there is a problem in that the thermal history of the semiconductor power element increases, and the characteristics of the hybrid integrated circuit are likely to deteriorate. An object of the present invention is to provide a method for manufacturing a power hybrid integrated circuit that reduces thermal history and prevents characteristic deterioration.

0004

[Means for Solving the Problems] The manufacturing method of the present invention includes placing a wiring board on which a solder layer has been previously formed on the metallized layer on both sides of the heat-dissipating substrate, placing a metal disk on top of the wiring board, and then placing a metal disk on top of the wiring board. Semiconductor power devices are stacked with solder pieces interposed therebetween, and then the solder is melted all at once in a reducing atmosphere to fix the heat dissipating substrate, the wiring board, and the semiconductor power device.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings. FIG. 1 is a sectional view of a power hybrid integrated circuit manufactured by the method of the present invention. The manufacturing process will be explained below. First, solder layers 4 are formed in advance on the metallized layer 3 formed on the front and back surfaces of the insulating wiring board 2. Then, the insulating wiring board 2 is placed on the heat-dissipating base 1, and a metal disk 5 made of copper is placed on top of it, and a power transistor 7 is placed on top of this with a sheet-like solder piece 6 interposed therebetween. In this state, a jig (not shown) is set to prevent misalignment so that the mutual positions of the parts are fixed, and the whole is passed through a reflow oven in a reducing atmosphere. As a result, the solder layers 4, 4 and the sheet-like solder piece 6 are melted all at once, and when solidified, the heat dissipating base 1, the insulating wiring board 2,
The power transistor 7 is integrally fixed.

[0006] In the above embodiment, an example of mounting a power transistor was shown, but it is also possible to mount a plurality of semiconductor power devices at the same time, and according to this method, a hybrid integrated circuit with high functionality can be realized. .

[0007]

As explained above, the present invention provides a wiring board on which a solder layer is previously formed on the metallized portions on both sides of a heat dissipating substrate, a metal disk, and a semiconductor power supply via a sheet-like solder piece. The devices are stacked one on top of the other, and then the solder is melted all at once in a reflow process in a reducing atmosphere to fix them together, making it possible to limit the thermal history of the semiconductor power device to just one cycle and prevent characteristic deterioration. It becomes possible to manufacture hybrid integrated circuits for suppressed power.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an integrated circuit manufactured by the manufacturing method of the present invention.

FIGS. 2(a) to 2(c) are cross-sectional views showing a conventional manufacturing method in the order of steps.

[Explanation of symbols]

1 Heat dissipating base 2 Insulating wiring board 3 Metallized layer 4,4 Solder layer 5 Metal disc 6 Sheet solder

Claims (1)

[Claims] 1. A method for manufacturing a power hybrid integrated circuit in which at least a semiconductor power element is mounted on a metallized substrate via a metal disk, and these are fixed to a heat dissipating base, in which both sides of the heat dissipating base are preliminarily mounted. A wiring board with a solder layer formed on it is placed on the metallized layer, a metal disk is placed on top of it, a semiconductor power device is placed on top of it via a sheet of solder, and then a single reflow process is performed in a reducing atmosphere. A method for manufacturing a power hybrid integrated circuit, characterized in that the solder is melted all at once to fix the heat dissipating base, the wiring board, and the semiconductor power device.