JP2003273318A - Electric power semiconductor module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric power semiconductor module by which a withstand voltage of a specified level or higher can be ensured. <P>SOLUTION: The electric power semiconductor module has several insulating substrates each of which is provided with a circuit structure including specified semiconductor chips on its surface on a metal base plate. In this case, insulating protrusions are arranged along the periphery of the circuits of the insulating substrates as means for ensuring the creepage distance for insulation among the insulating substrates. The protrusions are formed by making a resin material into a mound, are formed integrally with the insulating substrates, or are formed by bonding insulating frame members having a specified thickness to the insulating substrates. <P>COPYRIGHT: (C)2003,JPO

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 high withstand voltage and large current.

[0002]

2. Description of the Related Art As is well known, in a power semiconductor module in which a plurality of semiconductor chips are connected and housed in one package, in order to realize a high breakdown voltage and a large current, a dielectric breakdown voltage higher than a predetermined level is required. Is required to be secured. Conventionally, there has been known a power semiconductor module capable of ensuring an withstand voltage of, for example, AC 6 kV (rated 3.3 kV / 1200 A under a condition where a commercial frequency power source is applied for 1 minute).

8A and 8B are a plan view and a vertical cross-sectional explanatory view showing the external appearance of the body of a conventionally known power semiconductor module, respectively. Here, a diode module is taken as an example of the power semiconductor module. In this diode module 80, the external electrodes (anode electrode 83 and cathode electrode 84) are exposed on the upper surface side of the package 82, and a groove portion 82a is formed so as to pass between these electrodes. Groove 82
The a is formed so as to secure a predetermined insulation creeping distance or more between the anode electrode 83 and the cathode electrode 84.

Inside the package 82, an insulating metallized substrate 85 is bonded to a base plate 81 forming the bottom surface of the main body. The solder is shown at 93. Semiconductor chips 86 are mounted on the insulating metallized substrate 85, and these semiconductor chips 86 are connected to other components in the package through aluminum wires 87. Also, the package 82
Inside, a terminal 88 for taking out the anode electrode and a terminal 89 for taking out the cathode electrode are provided. These electrode lead-out terminals 88 and 89 are electrically connected to a specific semiconductor chip 86 at one end side thereof, and the external anode electrode 83 and cathode electrode 84 exposed at the upper surface side of the package 88 at the other end side. Electrically connected to.

Inside the package 82 having such a basic structure, the silicon gel 91 is injected into the space below it, and the insulating metallized substrate 85, the semiconductor chip 86, the aluminum wire 87, the electrode extraction terminals 88, 89, etc. are constructed. Is sealed. Furthermore, epoxy resin 9 is used in the upper space.
2 is filled.

FIG. 9 is a plan view schematically showing the structure of the diode module 80 on the base plate 81. A plurality of insulating metallized substrates 85 are arranged on the base plate 81, and the semiconductor chip 86 mounted on the insulating metallized substrate 85 and other components such as electrode lead-out terminals are connected to each other by aluminum wires 87. ing. FIG. 10 is an enlarged vertical cross-sectional explanatory view showing the base plate 81, the insulating metallized substrate 85, and the semiconductor chip 86 mounted thereon. The material of the insulating metallized substrate 85 is 0.6
A 35 mm thick AlN (aluminum nitride) substrate is used, and the front side and the back side of the substrate are about 0.1 to 0.35 mm.
A thick copper plate is joined by an active metal method or a direct bonding method. Base plate 81 and insulating metallized substrate 85,
Insulating metallized substrate 85 and semiconductor chip 86
Are joined by soldering. Reference numeral 93 represents solder. Normally, the insulation creepage distance on the front and back of the insulating metallized substrate 85 is set to about 2 mm. The aluminum wire 87 that connects the semiconductor chip 86 and each component such as the electrode lead-out terminal is bonded so that the height thereof is about 3 mm. To measure the withstand voltage of the diode module 10 having such a configuration, the withstand voltage between the base plate 81 to the anode electrode 83 and the cathode electrode 84 is measured after the module is assembled.

[0007]

In recent years, in the field of power semiconductor modules, higher breakdown voltage and higher current (for example, rated 6.5 kV / 600 A to 1200 A) have been demanded, and in order to meet this demand. There is a demand for a design technology that can realize a sufficient withstand voltage and guarantee a desired withstand voltage. As one means for increasing the withstand voltage,
It is generally known to set a large insulation creepage distance between an insulating metallized substrate, an aluminum wire, a package, a metal electrode, and the like. If the insulation creepage distance between the components is insufficient, a ground fault is likely to occur, and high reliability and safety of the module cannot be ensured. However, when this means is used, if the insulation creepage distance is increased in the direction of the straight line in which the components are arranged, the outer shape of the package itself becomes large and the cost also increases.

The present invention has been made in view of the above technical problems, and an object of the present invention is to provide a power semiconductor module having a structure capable of guaranteeing a predetermined insulation voltage or more.

[0009]

According to a first aspect of the present invention, there is provided a power semiconductor module in which a plurality of insulating substrates each having a circuit structure including a predetermined semiconductor chip on its surface are mounted on a metal base plate. The means for ensuring the insulation creepage distance between the insulating substrates is arranged at least at one of the peripheral edge of the insulating substrate and the vicinity thereof.

A second invention of the present application is the same as the first invention, wherein an insulating projection is provided on the surface of each insulating substrate along the peripheral edge around the circuit. It is characterized by.

Further, a third invention of the present application is characterized in that, in the above-mentioned second invention, the projection is applied so that a resin material is raised.

Furthermore, a fourth invention of the present application is characterized in that, in the above-mentioned second invention, the projection is formed integrally with the insulating substrate.

Furthermore, a fifth invention of the present application is the same as the second invention, wherein the projecting portion is an insulating frame member having a predetermined thickness with respect to the insulating substrate, and the insulating frame member is an insulating adhesive. It is characterized by being joined.

Furthermore, a sixth invention of the present application is the same as any one of the above-mentioned first to fifth inventions, wherein the outer peripheral surface of the insulating substrate is cut inward along the plane direction of the substrate. It is characterized in that a groove portion is formed.

Further, a seventh invention of the present application is the same as any one of the first to sixth inventions, wherein an insulating property is provided on a surface of each of the insulating substrates along a peripheral portion of the semiconductor chip. It is characterized in that a protrusion is provided.

[0016]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. Embodiment 1. 1A and 1B respectively show
FIG. 2 is a plan view and a side view showing the appearance of the main body of the power semiconductor module according to the first embodiment of the present invention. Here, a diode module is taken as an example of the power semiconductor module. This diode module 1
Reference numeral 0 indicates a basic module structure in which a plurality of semiconductor chips are mounted on an insulating metallized substrate 5 joined to a metal base plate 1 (shown by phantom lines) forming the bottom surface of the main body.
It has a structure housed in one package. External electrodes (anode electrode 4 and cathode electrode 5) for extracting electrodes from the semiconductor chip 6 are provided on the upper surface side of the package 2.
Is exposed. Further, in order to secure the insulation creepage distance between the anode electrode 4 and the cathode electrode 5, a groove portion 2a passing therethrough is formed. Preferably, the groove portion 2a ensures an insulating creepage distance of 20 mm or more between the anode electrode 4 and the cathode electrode 5.

An outer peripheral groove portion 2b running in the horizontal direction is formed on the outer peripheral surface of the package 2. In the first embodiment, two outer peripheral groove portions 2b that are parallel to each other are formed. By forming such an outer peripheral groove portion 2b, a sufficient insulation creepage distance in the thickness direction of the package 2 is secured. Preferably, the groove portion 2b allows the upper surface side and the lower surface side of the package 2 (that is, the metal base plate 1).
An insulation creepage distance of 50 mm or more is secured between the side) and the (side). The package 2 is attached to the base plate 1 by adhering or bonding the lower end of the package 2 to the peripheral edge of the base plate 1.

FIG. 2 is a plan view showing the internal structure of the diode module 10. On a metal base plate 1 forming the bottom surface of the module body, a plurality of insulating metallized substrates 5 on which various configurations including a power semiconductor chip are mounted are arranged on the surface. As the material of the metal base plate 1, a copper plate, AlSiC (aluminum silicon carbide), Cu-Mo (copper molybdenum), or the like is used. Although not particularly shown, its surface is plated with nickel. This surface treatment with nickel plating facilitates soldering. Also, the insulating metallized substrate 5
A resist pattern (not shown) is formed on the surface side on which the is arranged so that positioning can be facilitated when mounting.

As a material for the insulating metallized substrate 5, an AlN (aluminum nitride) substrate having a thickness of about 1 mm is used, and a copper plate (not shown) having a thickness of about 0.1 to 0.35 mm is active on the front and back sides thereof. It is joined by a metal method or direct bonding. For the same purpose as that of the metal base plate 1, the surface of the insulating metallized substrate 5 is plated with nickel, and further, on the front side on which other structures such as the semiconductor chip 4 and the electrode lead-out terminal are mounted, a resist is formed. A pattern (not shown) is formed.

As can be seen from FIG. 2, a plurality of insulating metallized substrates 5 are arranged on the metal base plate 1. Then, the other components such as the semiconductor chip 4 mounted on the insulating metallized substrate 5 and the electrode lead-out terminal are electrically connected to each other through the aluminum wire 9.
The aluminum wire 9 is joined using ultrasonic wire bonding. In this case, low temperature solder is used as the solder.

FIG. 3 is an enlarged longitudinal sectional view showing the metal base plate 1, the insulating metallized substrate 5 and the semiconductor chip mounted thereon in the diode module 10. The metal base plate 1 and the insulating metallized substrate 5 are joined by soldering. Further, the insulating metallized substrate 5 and the semiconductor chip 6 are joined by soldering. The solder between the components is indicated by reference numeral 11. In this case, medium temperature solder is used as the solder.

Although not particularly shown in the drawings, the invention of the present application is such that inside the package 1, silicon gel is injected into a space below the package 1 to form an insulating metallized substrate, a semiconductor chip, an aluminum wire, an electrode lead terminal and the like. Is sealed. Furthermore, the upper space is filled with epoxy resin.

In the first embodiment, the peripheral edge portion of each insulating metallized substrate 5 is provided with the peripheral edge protruding portion 7 formed by applying silicon (Si) rubber so as to bulge. Thereby, for example, an insulating creepage distance of 4 mm or more is secured between the insulating metallized substrates 5 (strictly, between the conductive portions of both).

Further, in the first embodiment, the aluminum wire connecting the semiconductor chip 4 mounted on the insulating metallized substrate 5 to another structure such as an electrode lead-out terminal is elevated from the chip surface to the highest position. Bonding is performed so that the thickness h is about 6 mm.

In the diode module 10 having such a structure, the insulating creepage distance is ensured by using the peripheral protrusions 7, so that adjacent insulating metallized substrates 5 are arranged close to each other while guaranteeing an insulating voltage higher than a predetermined level. You can As a result, it is possible to reduce the outer size of the package. Further, if necessary, the area where the circuit configuration is arranged on each insulating metallized substrate 5 can be expanded to the vicinity of the peripheral portion. In addition, in the measurement performed by the applicant of the present application, 10 k
It was confirmed that a withstand voltage of V or higher is guaranteed.

Next, another embodiment of the present invention will be described. Note that, in the following, the same components as those in the above-described first embodiment will be denoted by the same reference numerals, and further description will be omitted. Embodiment 2. FIG. 4 is an explanatory longitudinal sectional view showing, in an enlarged manner, a metal base plate, an insulating metallized substrate and a semiconductor chip mounted thereon in the diode module according to the second embodiment of the present invention. In the second embodiment, each insulating metallized substrate 25 has a peripheral rising portion 25a formed along the peripheral portion thereof as a means for ensuring the insulating creepage distance between the insulating metallized substrates 5. As a result, an insulating creepage distance of 4 mm or more is secured between the insulating metallized substrates 25, that is, between the conductive portions of the two.

According to the structure of the insulating metallized substrate 25, the adjacent insulating metallized substrates 25 can be arranged close to each other while ensuring an insulation voltage higher than a predetermined level, as in the effect obtained from the first embodiment. it can. As a result, it is possible to reduce the outer size of the package. Furthermore, according to the second embodiment, when the semiconductor chip 6 is soldered to the insulating metallized substrate 25 by the peripheral rising portion 25, the solder 11 around the substrate is soldered.
It is possible to reliably prevent the flow of.

Embodiment 3. FIG. 5 is a vertical cross-sectional explanatory view showing an enlarged metal base plate, an insulating metallized substrate and a semiconductor chip mounted thereon in the diode module according to the third embodiment of the present invention. This Embodiment 3
Then, as a means for ensuring an insulation creepage distance between the insulating metallized substrates 5, a peripheral projection member 32 made of an insulating material is bonded to each insulating metallized substrate 5 with an adhesive 35. Aluminum oxide (Al ₂ O ₃ ), silicon rubber, for example, can be used as the material of the peripheral protrusion member 32, and silicon rubber can be used as the adhesive 35.

The peripheral projection member 32 is formed in a rectangular frame shape, has a predetermined thickness and an outer size corresponding to the substrate 5, and is mounted on the insulating metallized substrate 5 so as to be insulated metallized substrate. 5 extends along the peripheral edge portion and projects upward by the thickness thereof. As a result, an insulating creepage distance of 4 mm or more is secured between the insulating metallized substrates 5, that is, between the conductive portions of the both.

By attaching the peripheral protrusion member 32 to the insulating metallized substrate 5, the insulating metallized substrate adjacent to the insulating metallized substrate 5 can be secured while ensuring an insulation voltage higher than a predetermined level, similar to the effect obtained from the first embodiment. 5 can be placed close together. As a result, it is possible to reduce the outer size of the package.

The peripheral edge protruding member 32 is not limited to the one formed in the rectangular frame shape, but is bonded to the insulating metallized substrate 5 and extends along the peripheral edge of the substrate while protruding upward. Any frame may be used, for example, by combining separate frames formed in a linear shape.

Fourth Embodiment FIG. 6 is an explanatory longitudinal sectional view showing, in an enlarged manner, a metal base plate, an insulating metallized substrate and a semiconductor chip mounted thereon in the diode module according to the fourth embodiment of the present invention. This Embodiment 4
Then, a means for ensuring the insulation creepage distance between the insulating metallized substrates 45 is provided in the vicinity of the peripheral edge of the insulating metallized substrate 45. That is, a groove 45a is formed on the outer peripheral surface of each insulating metallized substrate 45 by being cut inward along the plane direction of the substrate. As a result, between the insulating metallized substrates 45, that is, between the conductive portions of both, 4
An insulation creepage distance of at least mm is secured.

According to the structure of the insulating metallized substrate 45, adjacent insulating metallized substrates 45 can be arranged close to each other while guaranteeing an insulation voltage higher than a predetermined value, similar to the effect obtained from the first embodiment. it can. As a result, it is possible to reduce the outer size of the package.

Embodiment 5. FIG. 7 is an explanatory longitudinal sectional view showing, in an enlarged manner, a metal base plate, an insulating metallized substrate and a semiconductor chip mounted thereon in the diode module according to the fifth embodiment of the present invention. This Embodiment 5
Then, similar to the first embodiment described above, the peripheral edge portion of each insulating metallized substrate 5 is provided with the peripheral edge protruding portion 7 formed so that the silicon rubber is raised, and in addition to this, the semiconductor chip In the vicinity of the periphery of 6, there is provided a protrusion 57 which is also formed so that silicon rubber is raised. Thereby, each insulating metallized substrate 5
Insulation creepage distance of 4 mm or more is secured between the two, that is, between the conducting portions of both.

As described above, by providing the protrusions 7 and 57 in the vicinity of the periphery of the semiconductor chip 6 together with the peripheral portion of the insulating metallized substrate 5, the insulating metallized substrate adjacent to the insulating metallized substrate can be ensured while maintaining the insulation voltage above a predetermined level. 5 can be placed close together. As a result, it is possible to reduce the outer size of the package. Here, since the insulation creepage distance is doubly secured by the protrusions 7 and 57,
It is possible to further reduce the outer size of the insulating metallized substrate 5. Further, here, the protrusion 57 provided near the periphery of the semiconductor chip 6 makes it possible to protect the semiconductor chip 6 and also to improve the mechanical strength.

Needless to say, the present invention is not limited to the illustrated embodiments, and various improvements and design changes can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the diode module is taken up for description, but the present invention is also applicable to the IGBT module and the IPM module. Further, in the above-described embodiment, the means for ensuring the insulation creepage distance is provided on each insulation metallized substrate, but if possible, the means for ensuring the insulation creepage distance is shared between the adjacent insulation metallized substrates. You may.

[0037]

According to the invention of claim 1 of the present application, in each of the power semiconductor modules in which a plurality of insulating substrates having a circuit structure including a predetermined semiconductor chip on the surface thereof are mounted on a metal base plate, A means for ensuring an insulation creepage distance between the insulating substrates is provided at least at one of the peripheral edge portion of the insulation substrate and the vicinity thereof, and a sufficient insulation creepage distance is secured between the adjacent insulating substrates. The insulation voltage can be reliably ensured, and adjacent insulating substrates can be arranged close to each other.

Further, according to the invention of claim 2 of the present application, an insulating protrusion is provided on the surface of each insulating substrate along the peripheral portion around the circuit, and the insulating protrusion is provided between the adjacent insulating substrates. Since a sufficient insulation creepage distance is secured, it is possible to reliably guarantee a predetermined insulation voltage or more, and it is possible to arrange adjacent insulating substrates close to each other.

Further, according to the invention of claim 3 of the present application, since the resin material is applied to the protrusions so that the protrusions are raised, a relatively simple manufacturing process is used, and the insulating substrates are adjacent to each other. It is possible to secure a sufficient insulation creepage distance.

Further, according to the invention of claim 4 of the present application, since the projecting portion is formed integrally with the insulating substrate, the insulating substrate between adjacent insulating substrates is manufactured by using a relatively simple manufacturing process. It is possible to secure a sufficient insulation creepage distance in. Further, according to the present invention, when soldering the semiconductor chip to the insulating substrate, it is possible to prevent the solder from flowing around the substrate.

Further, according to the invention of claim 5 of the present application, the projecting portion is formed by bonding an insulating frame member having a predetermined thickness to the insulating substrate with an insulating adhesive. By using a relatively simple manufacturing process, a sufficient insulating creepage distance can be secured between the adjacent insulating substrates.

Furthermore, according to the invention of claim 6 of the present application, a groove portion formed by being cut inward along the plane direction of the insulating substrate is formed on the outer peripheral surface of the insulating substrate, and adjacent insulating layers are formed. Since a sufficient insulation creepage distance is secured between the substrates, an insulation voltage higher than a predetermined value can be reliably ensured, and adjacent insulating substrates can be arranged close to each other.

Further, according to the invention of claim 7 of the present application, an insulating protrusion is provided on the surface of each insulating substrate along the peripheral edge of the semiconductor chip, and the insulating substrate is adjacent to the insulating substrate. Since a sufficient insulation creepage distance is secured between them, it is possible to reliably ensure a predetermined insulation voltage or more, and it is possible to arrange adjacent insulating substrates close to each other. Further, according to the present invention, the semiconductor chip can be protected and the mechanical strength can be improved.

[Brief description of drawings]

FIG. 1A is a plan view showing an appearance of a main body of a power semiconductor module according to a first embodiment of the present invention. (B)
It is a side view which shows the external appearance of the main body of the power semiconductor module.

FIG. 2 is a plan view schematically showing an internal configuration of the power semiconductor module.

FIG. 3 is an explanatory longitudinal cross-sectional view showing an enlarged metal base plate, an insulating metallized substrate, and a semiconductor chip mounted thereon in the power semiconductor module.

FIG. 4 is an explanatory longitudinal sectional view showing, in an enlarged manner, a metal base plate, an insulating metallized substrate, and a semiconductor chip mounted thereon in the power semiconductor module according to the second embodiment of the present invention.

FIG. 5 is an enlarged vertical cross-sectional explanatory view showing a metal base plate, an insulating metallized substrate and a semiconductor chip mounted thereon in the power semiconductor module according to the third embodiment of the present invention.

FIG. 6 is an explanatory longitudinal sectional view showing, in an enlarged manner, a metal base plate, an insulating metallized substrate and a semiconductor chip mounted thereon in the power semiconductor module according to the fourth embodiment of the present invention.

FIG. 7 is a vertical cross-sectional explanatory view showing an enlarged metal base plate, an insulating metallized substrate and a semiconductor chip mounted thereon in the power semiconductor module according to the fifth embodiment of the present invention.

FIG. 8 (a) is a plan view showing the external appearance of the main body of a conventional power semiconductor module. (B) It is a longitudinal cross-sectional explanatory view schematically showing an internal configuration of a conventional power semiconductor module.

FIG. 9 is a plan view showing an internal configuration of a conventional power semiconductor module.

FIG. 10 is an explanatory longitudinal cross-sectional view showing an enlarged metal base plate, an insulating metallized substrate, and a semiconductor chip mounted thereon in a conventional power semiconductor module.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 metal base plate, 2 package, 2a, 2b groove part, 3, 4 external electrode, 5 insulating metallized substrate, 6 semiconductor chip, 7 peripheral protrusion part, 9 aluminum wire, 10
Power semiconductor module, 25a peripheral rising portion, 3
2 peripheral projection member, 35 adhesive, 45a groove, 57
Protrusions around the semiconductor chip

Claims (7)

[Claims] 1. In a power semiconductor module in which a plurality of insulating substrates having a circuit configuration including a predetermined semiconductor chip on the surface thereof are mounted on a metal base plate, an insulating creepage distance is secured between the insulating substrates. A power semiconductor module, wherein the means is disposed at least at one of the peripheral edge of the insulating substrate and the vicinity thereof. 2. The power semiconductor module according to claim 1, wherein an insulating protrusion is provided on the surface of each insulating substrate along the peripheral edge around the circuit. 3. The power semiconductor module according to claim 2, wherein the protrusion is formed by applying a resin material so as to be raised. 4. The power semiconductor module according to claim 2, wherein the protrusion is formed integrally with the insulating substrate. 5. The power semiconductor according to claim 2, wherein the protrusion is formed by bonding an insulating frame member having a predetermined thickness to the insulating substrate with an insulating adhesive. module. 6. The groove portion formed by cutting inward along the plane direction of the insulating substrate is formed on the outer peripheral surface of the insulating substrate. The power semiconductor module described. 7. The insulative protrusion is provided on the surface of each insulating substrate along the peripheral edge of the semiconductor chip. Power semiconductor module.