JPH03245559A - Semiconductor device - Google Patents

Abstract

PURPOSE:To lessen an insulating board in cost as a whole and to enable the characteristics of semiconductor elements to be easily measured by a method wherein the insulating board is provided for each of electrodes used for the connection to an external conductor, and the insulating boards are supported by a common supporting plate. CONSTITUTION:A high thermal conductive insulating board 4 and a low thermal conductive insulating board 41 are joined together on a support plate 5. An electrode plate 11 is fixed to the insulating board 4, electrode plates 12 and 13 are fixed to the insulating board 41. The ends of the electrode plates 11, 12, and 13 are stepped by processing to be higher than the other parts in level by their thicknesses, and connections 61, 62, and 63 are provided. After the electrode plates 11, 12, and 13 are fixed, the connections 61, 62, and 63 are made to extend outward from the support plate 5 and the insulating plates 4 and 41. The collector electrode of a transistor chip 1 and the cathodes electrode of a transistor chip 2 are joined to the electrode plate 11, the emitter electrode of the transistor chip 1 and the anode electrode of the transistor chip 2 are joined to the electrode plate 12, and the base electrode of the transistor chip 1 is joined to the electrode plate 13.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a semiconductor element having electrodes on both sides, in which an electrode on the lower surface is fixed to an electrode plate surface, and an electrode on the upper surface is connected to a different electrode plate by a conductive wire. The present invention relates to a semiconductor device.

[Conventional technology]

It is difficult to connect the electrodes provided on the surface of the semiconductor body to an external circuit using a direct connection conductor because it imparts mechanical strain to the semiconductor body, so it is usually done through an electrode plate. It will be done. FIG. 2 shows the internal structure of such a semiconductor device, which has one transistor chip 1 and one diode chip 2. A collector electrode on the lower surface of the transistor chip 1 is connected to an electrode plate 11,
Each of the four emitter electrodes on the top surface is connected to another electrode plate 12 using an aluminum conducting wire 3, and one base electrode is connected to another electrode plate 13 also using a conducting wire 3. The cathode electrode on the lower surface of the diode chip 2 is connected to the electrode plate 11, and the anode electrode on the upper surface is connected to the electrode plate 12 by a conductive wire 3.

The three electrode plates 11, 12, 13 are fixed on a common insulating plate 4. The semiconductor device shown in FIG. 3 has two transistor chips 1 connected in parallel and two diode chips 2 connected in parallel.

That is, the collector electrode on the lower surface of each transistor chip 1 and the cathode electrode on the lower surface of each diode chip 2 are connected to the upper surface of a common electrode plate 14, and the emitter electrode on the upper surface of the transistor chip 1 is connected to the common electrode by the conducting wire 3. The plate 15 and the base electrode are all connected to another common electrode plate 16 by conductive wires. "Also, the anode electrode on the top surface of each diode chip 2 is connected to the electrode plate 15 by a conductive wire 3. In this case, each electrode plate 14
．． 15 and 16 are fixed on a common insulating plate 4.

[Problem to be solved by the invention]

In the semiconductor device shown in FIGS. 2 and 3, heat generated in the semiconductor body 1.2 is radiated from the electrode on the lower surface via the electrode plate 11 or 14 and the insulating plate 4.

Therefore, the insulating plate 4 must serve both for electrical insulation between the electrode plates and for heat dissipation, and for this purpose ceramics having good thermal conductivity is used. Such ceramics include beryllia porcelain, but they are expensive. Also,
In order to measure the characteristics of a semiconductor element in the chip state, it is necessary to bring the probe into contact with each electrode, which is undesirable as there is a risk of damaging the semiconductor element.Therefore, after connecting each electrode to the electrode plate, This is generally done by bringing a probe into contact with the electrode plate. Therefore, in a semiconductor device in which a plurality of semiconductor elements are connected in parallel as shown in FIG. 3, the characteristics of each individual element cannot be measured, and the characteristics of the elements connected in parallel cannot be matched.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor device that solves the above-mentioned problems, reduces the cost required for an insulating plate, and allows easy measurement of the characteristics of individual semiconductor elements connected to each other. be.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a semiconductor device comprising a plurality of semiconductor bodies having electrodes on both sides, in which an electrode on the lower surface of one or more of the semiconductor bodies is fixed. The electrode plate connected to the electrode on the upper surface of each electrode plate and the electrode plate connected by a conductive wire are each fixed on a common support plate via separate insulating plates, and the semiconductor element part of one of the electrode plates is connected to the electrode plate from the support plate. It is assumed that the support plate is extended and that the extension part is stepped away from the surface of the support plate by the thickness of the support plate itself.

[Effect]

The electrode plate to which the semiconductor element is fixed by the lower electrode and the electrode plate to which the upper electrode is connected by the conductor are each fixed on the support plate through separate insulating plates. The insulating plate is used only under the electrode plate to which the semiconductor element that requires heat dissipation is fixed, and inexpensive insulating plates can be used for the other insulating plates, resulting in overall cost reduction.

Also, the connection between electrode plates fixed on separate support plates is
This can be easily done by overlapping and contacting the extension portion of the electrode plate that has come off the support plate with the upper surface of the electrode plate on another support plate that is on the same plane as the support plate. Therefore, the semiconductor elements whose characteristics need to be measured are mounted on separate support plates, the characteristics are measured in that state, and then the electrode plates are connected between the support plates on which semiconductor elements with matching characteristics are mounted. By performing these steps, the desired semiconductor device can be assembled.

〔Example〕

FIG. 1 shows one support plate portion which is a constituent unit of a semiconductor device according to an embodiment of the present invention. Components common to those in FIG. 3 are given the same reference numerals.

FIG. 1 (al indicates each component separately, FIG. 1 cb) shows the assembled state, and FIG. 1 (C1 shows the state after semiconductor elements are mounted. Support plate 5 is a metal plate such as aluminum, Two insulating plates 4 and 41 are bonded thereon.Insulating plate 4 is a high heat conductive insulating plate made of ceramic with good thermal conductivity such as Beryliya porcelain, but insulating plate 41 is made of ordinary ceramic. One electrode plate 11 is fixed on the insulating plate 4, and two electrodes 112.13 are fixed on the insulating plate 41. Electrode plate 11.1 The end of the '213 is stepped to be higher than the other parts by the thickness of the end to form a connecting part 6162.63.Then, the electrode plate 11, 12, 13 is fixed. After that, connect these connecting parts 61, 62.
63 projects outward from above the support plate 5 and the insulating plates 4 and 41. As shown in Figure 1 (C1), the electrode plate 1
The collector electrode on the lower surface of the transistor chip 1 and the cathode electrode on the lower surface of the diode chip 2 are bonded to each other by die bonding. @ [3, and the electrode plate 13 is connected to the upper base electrode of the transistor chip 1! The connection via i3 is the same as in the case of FIG.

FIG. 4 shows a semiconductor device in which two transistors are connected in parallel, forming the circuit shown in FIG.

Such a parallel connection of transistors 51, 52
The characteristics of the transistors whose characteristics were measured using the electrode plates 11 and 12.13 in the state shown in FIG. .62.63 to the electrode plates 11, 1 on the other support plate 5
This is achieved by overlapping and brazing on the edges of 2.13. 61st! I corresponds to the series connection of transistors 51 and 52 as shown in FIG. 7, and is an electrode plate on one of the two support plates 5 on which transistor chips 1 with matching characteristics are mounted. In this semiconductor device, the connecting portion 61 of the first electrode plate 11 and the connecting portion 62 of the electrode plate 12 on the other supporting plate 5 are connected by brazing the connecting piece 7.

Although diodes are connected in antiparallel to each transistor in FIGS. 4 and 6, the diodes are omitted in FIGS. 5, 1, and 7. However, since each diode chip 2 is fixed together with the transistor chip 1 on the electrode plate 11, when measuring the characteristics of the transistor using the electrode plate 11, the characteristics with the diodes connected in parallel are measured. be done. If it is necessary to measure the characteristics of only a single transistor, it is necessary to separate the electrode plate to which the transistor chip 1 is fixed and the electrode plate to which the diode chip 2 is fixed. After measuring the characteristics, both electrode plates may be connected using a connecting piece.

〔Effect of the invention〕

The present invention provides an insulating plate for each electrode plate for connection to an external connection conductor, and by supporting the insulating plate by a common support plate, only the insulating plate under the electrode plate to which the semiconductor element is fixed is provided. Since it is only necessary to use expensive insulating plates with good thermal conductivity, and there is no need to use large-area insulating plates that are difficult to manufacture, the cost of each insulating plate is reduced below the area ratio. The overall cost is reduced and an inexpensive semiconductor device can be obtained. Furthermore, by fixing each semiconductor element whose characteristics need to be measured on a separate electric bridge board, the characteristics of each semiconductor element can be easily measured before circuit configuration, and the characteristics and non-defective rate after circuit configuration can be easily measured. can be improved.

[Brief explanation of drawings]

1st TyJ shows the main parts of the constituent units of a semiconductor device according to an embodiment of the present invention, of which (Jl) is a perspective view of each part, (
bl is a perspective view after the electrode plate is assembled, (C1 is a perspective view after mounting a semiconductor element, FIG. 2 is a perspective view of a main part of an example of a conventional semiconductor device, and FIG. 3 is a perspective view of another example of a conventional semiconductor device. 4 is a perspective view of an example of a semiconductor device using the structural units shown in FIG. 1, FIG. 5 is an equivalent circuit diagram thereof, and FIG. 6 is a semiconductor device using the structural units shown in FIG. 1. A perspective view of another example, and FIG. 7 is its equivalent circuit diagram. 1: Transistor chip, 11.12. i3: Electrode plate, 2: Diode chip, 3: Conductive wire, 4: High heat conductive insulating plate, 41 :Low thermal conductivity insulating plate, 5: Support plate, 61゜2 63: Connection part.'-ゝ＼

Claims (1)

[Claims] 1) In a device consisting of a plurality of semiconductor bodies having electrodes on both sides, an electrode plate to which an electrode on the bottom surface of one or more of the semiconductor bodies is fixed, and an electrode and a conductor on the top surface of each semiconductor body. The electrode plates to be connected are each fixed on a common support plate via separate insulating plates, one end of each electrode plate is extended off the support plate,
A semiconductor device characterized in that the extended portion is stepped away from the surface of the support plate by the thickness of the semiconductor device itself.