JP2000031358A - Power semiconductor module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of manufacturing processes and a cost by providing a recessed part at a specified position when stamping a metal base. SOLUTION: A copper plate, for example, of a regular size or band-like shape is stamped out to provide a metal base. At stamping, a specified position of the metal base is applied with a pressure to form a first recessed part 1a on the surface. After formation of the recessed part 1a, a solder foil 5 is inserted in the recess, and an insulating substrate 4 of a ceramic plate, etc., which has a circuit arrangement of silver foil is mounted on the solder foil 5. Further, a power semiconductor chip 8 is mounted at a specified position on one surface of the insulating substrate 4 through a solder foil 7. When they are heated, the power semiconductor chip 8 is soldered to a specified position of the metal base 1 through the insulating substrate 4 by the recessed part 1a provided at the specified position of the metal base 1. Thus, the number of processes is reduced, resulting in a low-cost power semiconductor module.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power semiconductor module having a power semiconductor chip mounted on a metal base.

[0002]

2. Description of the Related Art Conventionally, a power semiconductor is mounted on a metal base by mounting an insulating substrate such as a ceramic plate on which a circuit is formed by copper foil, and further mounting a power chip on the insulating substrate and soldering each. There is a module. In this power semiconductor module, the output terminal plate is connected to the power semiconductor chip directly or by a wire. If accurate positions of the power semiconductor chip and the output terminal board are not obtained, there are quality problems such as distortion of the output terminals and insufficient soldering.

For this reason, various methods have been proposed for mounting a power semiconductor chip at a correct position. For example, FIG.
Is coated with a resist on a metal base 51 to provide a layer 52 to which solder does not fit. An insulating substrate 5 having a metal layer formed on both surfaces is formed in an opening 52a of the solder to which it does not fit.
4 are mounted via the solder foil 55. Further, on one surface of the insulating substrate 54, a power semiconductor chip 58 is mounted via a solder foil 57 at a predetermined position determined by copper foil and plating. These metal bases 5
1, the metal base 51, the insulating substrate 54, and the power semiconductor chip 58 are soldered by placing the solder 55, the insulating substrate 54, the solder 57, and the power semiconductor chip 58 in a reflow furnace and heating.

As a result, the power semiconductor chip 58 is soldered to a predetermined position on the metal base 51.

When the power semiconductor chip 62 is directly soldered to the metal base 61 as shown in FIG. 6, a spatial distance A between the metal base 61 and the upper semiconductor layer 62a of the power semiconductor chip 62 is obtained. Is small, the solder layer for soldering the metal base 61 and the power semiconductor chip 62 causes a short circuit between the metal base 61 and the semiconductor layer 62a above the semiconductor chip 62, so that a sufficient withstand voltage cannot be obtained. was there.

[0006]

In the power semiconductor module shown in FIG. 5, there is a problem that the process is used frequently, such as the necessity of applying a resist and drying the resist for positioning on the metal base. There is. In addition, a jig, a mask, and the like for applying a resist are required, and this is a factor that makes the power semiconductor module expensive.

In the power semiconductor module of FIG. 6, a metal such as copper or molybdenum is preliminarily spread under the power semiconductor chip 62 in order to prevent a short circuit between the metal base 61 and the semiconductor layer 62a. Soldered with high temperature solder. For this reason, in the manufacturing process of the power semiconductor module, the number of steps of soldering a metal such as copper or molybdenum to the power semiconductor chip has increased, which has caused the power semiconductor module to be expensive.

[0008]

According to a first aspect of the present invention, there is provided a power semiconductor module comprising a metal base and a power semiconductor chip mounted thereon, wherein the metal base has a concave portion at a predetermined position when the metal base is punched. Is a metal base provided.

The metal base is formed, for example, by stamping a fixed-size or band-shaped copper plate. During this punching process, pressure is applied to a predetermined position, for example, 0.3 to 0.8.
A recess of about mm is provided.

That is, the recess is formed simultaneously with the punching of the metal base.

According to a second aspect of the present invention, the power semiconductor module is a metal base having a concave portion provided at a predetermined position where the power semiconductor chip is mounted when the metal base is punched.

The metal base is formed, for example, by stamping a fixed-length or band-shaped copper plate. During this punching process, a pressure is applied to a predetermined position where the power semiconductor chip is mounted, so that a concave portion of, for example, about 0.3 to 0.8 mm is provided. A solder foil is mounted in the recess, and an insulating substrate such as a ceramic or the like is mounted directly on the solder foil, and a power semiconductor chip is mounted and heated and soldered.

According to a third aspect of the present invention, the power semiconductor module is a metal base having a concave portion provided at a position indicating a position at which the power semiconductor chip is mounted when the metal base is punched.

The metal base is formed, for example, by punching a fixed-size or band-shaped copper plate. During this punching process, pressure is applied to a position indicating the position where the power semiconductor chip is to be mounted, so that a concave portion of, for example, about 0.3 to 0.8 mm is provided. A solder foil is mounted in the recess, an insulating substrate is mounted on the solder foil, and a power semiconductor chip is mounted, heated and soldered.

According to a fourth aspect of the present invention, the power semiconductor module is a metal base having a concave portion surrounding a predetermined position where the power semiconductor chip is mounted when the metal base is punched.

The metal base is formed, for example, by punching a fixed-size or band-shaped copper plate. During this punching process, a pressure is applied so as to surround a predetermined position on which the power semiconductor chip is mounted, so that a concave portion of, for example, about 0.3 to 0.8 mm is provided. A power semiconductor chip is mounted on a turret surrounded by the concave portion via a solder foil, heated and soldered.

According to a fifth aspect of the present invention, there is provided a power semiconductor module having a metal base, an insulating substrate mounted on the metal base, an output terminal mounted on the insulating substrate, and mounted on the output terminal. Power semiconductor chip,
The output terminal is an output terminal in which a punching process is performed on the output terminal, and a concave portion is provided at a predetermined position during the punching process.

The output terminal is formed, for example, by stamping a fixed-size or band-shaped copper plate. During this punching process,
A pressure is applied to a predetermined position on which the power semiconductor chip is mounted, so that a recess of, for example, about 0.3 to 0.8 mm is provided. This recess is formed simultaneously with the punching of the output terminal.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes a metal base, for example, a standard-size or band-shaped copper plate is punched to obtain a metal base. During this punching process, pressure is applied to a predetermined position of the metal base to form a first concave portion 1a having a surface of about 0.3 to 0.8 mm. After the formation of the concave portion 1a, the solder foil 5 is inserted into the concave portion, and the insulating substrate 4 such as a ceramic plate or the like arranged by copper foil on the solder foil 5 is mounted.
Further, a solder foil 7 is provided at a predetermined position on one surface of the insulating substrate 4.
The power semiconductor chip 8 is mounted via the power supply. When the metal base 1, the solder 5, the insulating substrate 4, the solder 7, and the power semiconductor chip 8 are heated in a freezing furnace, the metal base 1, the insulating substrate 4, and the power semiconductor chip 8 are soldered.

The power semiconductor chip 8 is connected to the insulating substrate 4 by a concave portion provided at a predetermined position of the metal base 1.
Is soldered to a predetermined position of the metal base 1 through the metal. Thus, there is no need to provide a manufacturing process such as applying and drying a resist as in the related art. Further, a jig, a mask, and the like for applying the resist are not required.

Next, a second embodiment will be described with reference to FIG. In FIG. 2, reference numeral 11 denotes a metal base. For example, a metal plate 11 is obtained by punching a fixed-size or band-shaped copper plate. During this punching, pressure is applied to a predetermined position of the metal base 11 to form a second concave portion 11a having a surface of about 0.3 to 0.8 mm.

At least two concave portions 11a are provided in the shape of brackets, and an insulating substrate 14 is mounted on the inside of the concave portions of the brackets via solder foil. The semiconductor chip 15 is mounted, placed in a reflow furnace and heated, and the metal base 11 and the power semiconductor chip 15 are soldered. Thus, there is no need to provide a manufacturing process such as applying and drying a resist as in the related art. Further, a jig, a mask, and the like for applying the resist are not required.

Next, a third embodiment will be described with reference to FIG. In FIG. 3, reference numeral 21 denotes a metal base, for example, a standard-size or band-shaped copper plate is punched to obtain a metal base 21. During this punching process, pressure is applied to a predetermined position of the metal base 21 to form a third recess 21a having a surface of about 0.3 to 0.8 mm. The concave portion 21a is provided so as to surround a part of the metal base, and the center thereof is
As seen from a, a turret having a convex portion 21b is formed.

The power semiconductor chip 22 is mounted on the projecting turret 21b via the solder foil 23, and is placed in a freezer furnace and heated, so that the metal base 21 and the power semiconductor chip 22 are heated.
And are soldered. Therefore, there is no short circuit between the metal base 21 and the upper semiconductor layer of the power semiconductor chip 22, so that it is also necessary to solder a metal such as copper or molybdenum under the power semiconductor chip 22 in advance as in the prior art. Absent.

Next, a fourth embodiment will be described with reference to FIG. In FIG. 4, reference numeral 31 denotes a metal base, on which an insulating substrate 32 in which circuits are arranged by copper foil is mounted. Further, the insulating substrate 32
The output terminal 33 is mounted on. This output terminal 3
3 is. For example, it is obtained by punching a fixed-size or band-shaped copper plate. At the time of this punching, pressure is applied to a predetermined position of the output terminal 33 to form fourth and fifth recesses 33a and 33b having a surface of about 0.3 to 0.8 mm.

A solder foil 34a is inserted into the fourth recess 33a, and the power semiconductor chip 3 is placed on the solder foil 34a.
5a is mounted.

Further, the fifth concave portion 33b is provided so as to surround a part of the output terminal, and the center thereof forms a turret having a convex portion 33c as viewed from the concave portion 33b.

The power semiconductor chip 35b is mounted on the projecting turret 33c via the solder foil 34b, placed in a freezing furnace and heated to solder the metal base 31 and the power semiconductor chips 35a and 35b. ing.

Therefore, it is not necessary to provide a manufacturing process such as applying and drying a resist in the fourth concave portion 33a. Further, a jig, a mask, and the like for applying the resist are not required. Further, in the fifth concave portion 33b, the metal base 31 is formed.
There is no short circuit between the power semiconductor chip 35b and the semiconductor layer above the power semiconductor chip 35b, so that it is not necessary to solder a metal such as copper or molybdenum under the power semiconductor chip 35b in advance as in the related art.

[0030]

According to the power semiconductor module according to the first to third and fifth aspects, there is no need to provide a manufacturing process such as drying without applying a resist as in the prior art. Also, a jig mask or the like for applying a resist is not required.
Therefore, an inexpensive power semiconductor module can be provided.

According to the power semiconductor module of the first, fourth and fifth aspects, it is not necessary to previously provide a metal such as copper or molybdenum under the power semiconductor chip as in the prior art. Thus, the number of steps in the manufacturing process can be reduced, and the power semiconductor module can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a sectional view of a power semiconductor module according to a first embodiment of the present invention at the time of assembly.

FIG. 2 is a plan view of a power semiconductor module according to a second embodiment of the present invention at the time of assembly.

FIG. 3 is a sectional view of a power semiconductor module according to a third embodiment of the present invention at the time of assembly.

FIG. 4 is a sectional view of a power semiconductor module according to a fourth embodiment of the present invention at the time of assembly.

FIG. 5 is a cross-sectional view of a conventional power semiconductor module during assembly.

FIG. 6 is a cross-sectional view of another conventional power semiconductor module during assembly.

[Explanation of symbols]

 1, 11, 21, 31 Metal base 1a, 11a, 21a, 33a, 33b Concave portion 11b, 33c Convex portion (battery) 4, 14, 32 Insulating substrate 5, 7, 23, 34a, 34b Solder foil 8, 15, 22 .35a, 35b Power semiconductor chips

Claims (5)

[Claims] 1. A power semiconductor module having a power semiconductor chip mounted on a metal base, wherein the metal base is a metal base having a concave portion provided at a predetermined position during punching. module. 2. The power semiconductor module according to claim 1, wherein the metal base is a metal base having a recess at a predetermined position where the power semiconductor chip is mounted at the time of punching. 3. The power semiconductor module according to claim 1, wherein the metal base is a metal base provided with a concave portion at a position indicating a position where the power semiconductor chip is mounted at the time of punching. . 4. The power semiconductor module according to claim 1, wherein the metal base is a metal base provided with a concave portion so as to surround a predetermined position where the power semiconductor chip is mounted at the time of punching. . 5. A power supply comprising: a metal base; an insulating substrate mounted on the metal base; an output terminal mounted on the insulating substrate; and a power semiconductor chip mounted on the output terminal. A power semiconductor module according to claim 1, wherein said output terminal is an output terminal provided with a recess at a predetermined position during punching.