JPH1027869A - Circuit board for semiconductor device and composite semiconductor device provided therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen a circuit board and a semiconductor device in size by a method wherein a signal circuit pattern is set to be 1.0mm or below in minimum width. SOLUTION: A semiconductor device circuit board 3 is equipped with an aluminum nitride board 31 possessed of a conductor pattern 4 of metal plate and a signal circuit pattern 60 of metallized layer mixedly bonded to its one primary surface and a metal plate bonded to all its other primary surface. Or, a composite semiconductor device 1 is equipped with an aluminum nitride board 31 possessed of a conductor pattern 4 of metal plate and a signal circuit pattern 60 of metallized layer mixedly bonded to its one primary surface, where semiconductor chips 5 are mounted on the conductor pattern 4 of metal plate, and the signal circuit pattern 60 of metallized layer is made to serve as the signal circuit wiring of a semiconductor chip 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a miniaturized circuit board using an aluminum nitride substrate and a composite semiconductor device using the circuit board.

[0002]

2. Description of the Related Art FIG. 2 shows a schematic structure of a composite semiconductor device of this kind. In the figure, reference numeral 1 denotes the entire composite semiconductor device. Reference numeral 2 denotes a heat sink on which a circuit board 3 for a semiconductor device is mounted and fixed.

[0003] A conductor pattern 4 is formed on the circuit board 3, a semiconductor chip 5 is mounted and fixed on the conductor pattern 4, and the semiconductor chip 5 and the signal circuit pattern 6 are connected by bonding wires 7. ing. The lower ends of the plurality of external lead-out terminals 8 are fixed to predetermined positions of the conductor pattern 4, and the other ends are led out from a lid 10 that closes an opening of the insulating case 9. The lower end of the insulating case 9 is fixed to the outer periphery of the heat sink 2.

Next, FIG. 3 shows a plan view of the circuit board 3 for a semiconductor device, and details thereof will be described. The circuit board 3 has an aluminum nitride substrate 31 having a thickness of about 0.6 mm, and a metal plate such as a copper plate having a thickness of 0.3 mm is fixed on the entire back surface of the aluminum nitride substrate 31. .
On the front side of the circuit board 3, for example,
Conductor pattern 4 made of a metal plate such as a 3 mm thick copper plate
Are formed. The hatched portion in the conductor pattern 4 is the external lead terminal fixing portion 32.

A central portion of the aluminum nitride substrate 31,
That is, the signal circuit pattern 6 whose one end extends thinly is formed in the concave portion of the conductor pattern 4 formed in a substantially U-shape. This signal circuit pattern 6 is also formed of a metal plate made of, for example, a copper plate having a thickness of 0.3 mm, and has a width W of about 1.0 mm.
mm. This is because when the width W is less than 1.0 mm, it is difficult to press a metal plate such as a copper plate. The hatched portion in the signal circuit pattern 6 is the signal terminal fixing portion 33.

[0006]

As described above, the conventional signal circuit pattern 6 uses a metal plate made of a copper plate or the like as in the case of the conductor pattern 4 as described above. W must be about 1.0 mm. On the other hand, in order to reduce the size of the device, the size of the circuit board 3 itself must be reduced. However, due to the above-described processing restrictions, it is impossible to sufficiently reduce the size of the device. There were issues to be addressed.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and can reduce the minimum width of a signal circuit pattern to 1.0 mm or less, thereby realizing a miniaturization of a circuit board. Accordingly, it is an object of the present invention to provide a circuit board for a semiconductor device which can sufficiently contribute to miniaturization of the device itself, and a composite semiconductor device using the same.

[0008]

According to a first aspect of the present invention, there is provided a circuit board for a semiconductor device, comprising: a first circuit pattern having a metal plate fixed to one main surface of an aluminum nitride substrate; The circuit pattern is mixed, and a metal plate is fixed on the entire other main surface. A composite semiconductor device according to a second aspect of the present invention includes a first circuit pattern in which a metal plate is fixed to one main surface of an aluminum nitride substrate, and a second circuit pattern formed of a metallized layer, which is formed of the metal plate. A semiconductor chip is mounted on the first circuit pattern, and a second circuit pattern formed of a metallization layer is used as a wiring of a signal circuit of the semiconductor chip.

[0009]

Embodiments of the present invention will be described below with reference to FIG. First, the present invention has been made in response to the demand for miniaturization of the device itself, which naturally also requires miniaturization of the circuit board for semiconductor device used therein. In other words, focusing on the fact that the current flowing in the signal circuit pattern is small, it is based on the idea that it is not necessary to use a metal plate that is difficult to process. In addition, the minimum width W of the signal circuit pattern is set to 1.0 mm without using a metal plate.
If it can be made below, the outer shape of the entire circuit board can be reduced, which can ultimately contribute to miniaturization of the device.

Therefore, the second semiconductor device circuit board 3
The signal circuit pattern 60, which is a circuit pattern of the above, is characterized by being formed by a metallized layer without using a metal plate made of a copper plate or the like as in the related art. The portion of the other conductor pattern 4 that is the first circuit pattern is formed using a metal plate made of a copper plate or the like as in the related art. An embodiment of the present invention will be described below.

[0011]

1, a metallized layer having a thickness of about 30 .mu.m is formed as a signal circuit pattern 60 on the surface of an aluminum nitride substrate 31 by a known method. On the other hand, the other portions of the conductor pattern 4 are formed using a metal plate made of, for example, a copper plate having a thickness of 0.3 mm as in the related art. As described above, since the signal circuit pattern 60 is formed of the metallized layer, the minimum width W can be easily reduced to 1.0 mm or less without being affected by the difficulty of processing the metal plate as in the related art. For this reason, the dimension W1 of the concave portion 4a of the conductor pattern 4 can be reduced, and finally, the outer dimension W2 of the semiconductor device circuit board 3 itself can also be reduced. The formation of the metallized layer of the signal circuit pattern 60 can be performed simultaneously with the formation of the metallized layer for fixing the metal plate of the conductor pattern 4, so that the number of manufacturing steps is not particularly increased.

As a result, when assembling the composite semiconductor device as shown in FIG. 2 using the miniaturized circuit board 3 for a semiconductor device, the larger the number of the circuit boards 3 is, the more the overall device becomes. The contribution rate to miniaturization is large, and the effect is enormous.

[0013]

As described above, in the semiconductor device circuit board of the present invention, the second circuit pattern portion is formed by the metallized layer, so that the minimum width due to the difficulty in processing the metal plate is obtained. Restrictions are relaxed, and a circuit board that is relatively small compared to the related art can be manufactured, which can contribute to cost reduction. Further, even in a composite semiconductor device using the above-described circuit board, there is an advantage that the size of the entire device can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of a circuit board for a semiconductor device of the present invention.

FIG. 2 is a cross-sectional view showing a schematic structure of a composite semiconductor device assembled using conventional and semiconductor device circuit boards.

FIG. 3 is a plan view of a conventional circuit board for a semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Composite semiconductor device 2 Heat sink 3 Circuit board for semiconductor devices 4 Conductor pattern 5 Semiconductor chip 6,60 Signal circuit pattern 31 Aluminum nitride substrate

Claims (3)

[Claims] 1. A first circuit pattern having a metal plate fixed thereto and a second circuit pattern comprising a metallized layer are mixed on one main surface of the aluminum nitride substrate, and the other main surface is formed on the entire surface of the metal plate. A circuit board for a semiconductor device, wherein the circuit board is fixed. 2. The method according to claim 1, wherein the second circuit pattern is provided between the first circuit patterns.
2. The circuit board for a semiconductor device according to claim 1, wherein a part of the circuit pattern is arranged in a complicated manner. 3. A first circuit pattern comprising a metal plate and a second circuit pattern comprising a metallized layer mixed on one main surface of an aluminum nitride substrate. A composite semiconductor device having a semiconductor chip mounted thereon and a second circuit pattern formed of a metallization layer used as a wiring of a signal circuit of the semiconductor chip.