JP2848068B2 - Semiconductor device - Google Patents

Abstract

PURPOSE:To provide a power semiconductor device, e.g. a power transistor module, in which overall downsizing is realized by reducing the required area of metallic insulating board while ensuring high heat dissipation properties and noise resistance. CONSTITUTION:A metallic insulating board 1, a semiconductor chip (power transistor) 2 mounted on the metallic insulating board 1, control circuit components 3, and external lead out terminals 4 are built in a resin case 5. An intermediate partition wall 5a covering the top surface area of the metallic insulating board 1 other than the mounting area of the semiconductor chip 2 is provided at an intermediate stage in the case 5. The external lead out terminals 4, control circuit components 3, and wiring conductors therefor are arranged on the top surface side of the intermediate partition wall 5a while being isolated from the semiconductor chip 2, which is mounted through a heat plate 6 onto the metallic insulating board 1 on the side where a metallic foil 1c is not patterned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a semiconductor device for a power transistor module or the like.

[0002]

2. Description of the Related Art In recent years, as a circuit board of a semiconductor device, an example in which a metal insulating substrate is adopted tends to be widespread in terms of product cost, workability, mass productivity, heat dissipation, and the like. next,
FIG. 3 shows a conventional structure of a semiconductor device employing a metal insulating substrate, taking a power transistor module as an example. In the figure, reference numeral 1 denotes a metal insulating substrate in which a metal base 1a, an insulating layer 1b having good heat conductivity, and a metal foil 1c are integrated and a circuit pattern is formed on the metal foil 1c, 2 denotes a power transistor (bare chip), and 3 denotes a control circuit. And 4 are external lead-out terminals and 5 is a resin case. Here, the power transistor 2 is mounted on the metal foil 1c of the metal insulating substrate 1 via the metal plate 6 for heat dissipation, and the other components 3 and the external lead terminals 4 are distributed and mounted on the circuit pattern of the metal insulating substrate 1, respectively. Internal connection (wire bonding) between the power transistor 2 and the power transistor 2 via a wire 7
Have been. The bare chip power transistor 2
Is filled with a gel filler inside the case 5, or the chip is sealed with resin by coating, potting, or the like with a sealing resin.

[0003]

By the way, the power semiconductor devices such as the power transistor module described above tend to have an increasing capacity, while miniaturization of the semiconductor device is a major design problem. It has become a challenge. In this regard, in the structure in which all the circuit components are directly mounted on one metal insulating substrate as shown in FIG. 3, there is a limit to downsizing of the device for the following reasons.

(1) In the case where a conductor pattern is formed by patterning the metal foil 1c of the metal insulating substrate 1, it is necessary to secure an insulation creepage distance commensurate with the applied voltage between the conductor patterns separated from each other. . In particular, since a large voltage difference is applied between the main circuit and the control circuit during use, a large creepage distance exists between the conductor pattern on which the power transistor 2 is mounted and the conductor pattern on which the chip component 3 of the control circuit is mounted. This necessitates the required area of the metal insulating substrate to be increased, and the overall size of the device is increased.

(2) The heat generated by the power transistor 2 being energized is transmitted to the metal plate 6 and the metal insulating substrate 1 and is radiated to the heat sink. 1c is patterned and mounted on a part of the pattern.
Since the heat transfer path from the substrate to the metal base 1a of the metal insulating substrate 1 is limited to a narrow range, sufficient heat dissipation cannot be obtained. Therefore, in order to secure sufficient heat dissipation, it is necessary to use a metal insulating substrate having a large area.

(3) Further, in a structure in which main circuit components, control circuit components, and the like are mounted side by side on the same metal insulating substrate, noise immunity to a control circuit in particular is reduced. That is,
When pulsed noise enters the main circuit, the metal insulating substrate 1
The noise current flows to the control circuit component via the conductor pattern of the insulating layer (dielectric) 1b and the metal foil 1c. In addition, since the insulating layer 1b is extremely thin in consideration of heat conductivity, the noise current increases, and the semiconductor device may malfunction.

The present invention has been made in view of the above points, and has as its object to reduce the required area of a metal insulating substrate for a power semiconductor device while ensuring high heat dissipation and noise immunity. An object of the present invention is to provide a semiconductor device configured so that the entire device can be reduced in size.

[0008]

In order to achieve the above object, a semiconductor device according to the present invention is characterized in that a semiconductor chip mounting area is not provided at a middle position in a resin case, which is an envelope, so that a top surface of a metal insulating substrate is not provided. A partition wall that covers the area is provided, and external lead-out terminals, control circuit components, and their wiring conductors are arranged on the upper surface side of the partition wall.

Further, as an embodiment of the above configuration, there is the following configuration. (1) The external lead-out terminal and the wiring conductor of the control circuit component are inserted into the partition wall of the case in advance and integrally molded. (2) A semiconductor chip is mounted on a metal insulating substrate via a metal plate for heat radiation while a metal foil is adhered over the entire surface of the metal insulating substrate. Further, the heat-dissipating metal plate covers substantially the entire area of the metal foil of the metal insulating substrate and is thermally conductively bonded.

[0010]

According to the above construction, only the semiconductor chip (power chip) is mounted on the metal insulating substrate, and all other control circuit components, their wiring conductors, and external lead terminals are isolated from the metal insulating substrate. It is installed by inserting it into the partition wall of the case. With this, first,
The dielectric strength between the semiconductor chip, which is the main circuit component, and other circuit components is sufficiently ensured by the partition wall of the case, so there is no need to secure the required insulation creepage distance on the metal insulating substrate. Thus, the mounting density of the entire device can be increased. In addition, the heat generated by energization of the semiconductor chip (power chip) is not disturbed by the arrangement of other mounting components, and the heat flux is diffused to the entire surface of the metal insulating substrate through the heat-dissipating metal plate to conduct heat. High heat dissipation is ensured. in addition,
The control circuit chip components are separated from the main circuit components by the semiconductor chip and the case partition walls. Can be secured.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In the figure, the same members corresponding to FIG. 3 are denoted by the same reference numerals. Example 1 In FIG. 1, the metal insulating substrate 1 incorporated in the resin case 5 is unpatterned with the metal foil 1c formed on the entire surface of the insulating layer 1b (commonly referred to as a “solid” pattern state). The power transistor 2 is mounted at a predetermined position of the metal insulating substrate 1 via a heat-dissipating metal plate (for example, a copper plate) 6. On the other hand, a middle partition wall 5a is provided at a middle position inside the resin case 5 so as to cover the upper surface area of the metal insulating substrate 1 without the mounting area of the power transistor 2, and the upper surface side of the middle partition wall 5a. A wiring conductor 8 for connecting the control circuit component 3 and an external lead-out terminal 4 are provided, and the control circuit component 3 is soldered on the wiring conductor 8. The external lead-out terminals 4 and the wiring conductors 8 are integrally formed by inserting them when the case 5 is molded.

According to such a configuration, the insulation withstand required between the main circuit and the control circuit components is determined by the partition wall 5 a of the case 5.
Since it is secured by itself, a higher mounting density is possible. Further, the heat generated by energization in the power transistor 2 is transmitted through the metal plate 6 such that the heat flux is diffused to the entire surface of the metal insulating substrate 1 without being disturbed by other components, and is transmitted from the metal base 1a. Dissipates heat to an external heat sink. Therefore, even if the metal insulating substrate has a small area, high heat dissipation to the power transistor 2 having a large power capacity can be ensured, and the entire device can be made smaller. In addition, the heat generated by energization of the control circuit component 3 and the like is very small, and there is no problem in practical use even if the heat is installed on the partition wall 5a of the case 5. Further, since the control circuit components 3 and the like are arranged on the intermediate partition plate 5a separately from the power transistor 2 and the metal insulating substrate 1, higher noise immunity to external noise can be obtained as compared with the configuration of FIG.

Second Embodiment FIG. 2 shows a further development of the first embodiment described above in which the heat radiation is enhanced. The heat radiation metal plate 6 has a substantially entire area of the metal foil 1c of the metal insulating substrate 1. A metal plate having a large area covering the metal foil is incorporated, and the entire surface is thermally conductively bonded to the metal foil 1c of the metal insulating substrate. With this configuration, the heat generated by the power transistor 2 due to energization is diffused to the large-area metal plate 6 for heat dissipation and is transferred to the metal insulating substrate 1, so that the heat resistance of the heat dissipation path is low and higher heat dissipation is obtained. Will be able to

[0014]

As described above, according to the configuration of the semiconductor device according to the present invention, a high packaging density can be achieved for a power semiconductor device such as a power transistor module while ensuring a high insulation resistance and a noise resistance. At the same time, the required area of the metal insulating substrate can be reduced, and the size of the entire device can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration sectional view of a semiconductor device according to a first embodiment of the present invention;

FIG. 2 is a configuration sectional view of a semiconductor device according to a second embodiment of the present invention;

FIG. 3 is a configuration sectional view of a conventional semiconductor device for a power transistor module.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 metal insulating substrate 1 a metal base 1 b insulating layer 1 c metal foil 2 power transistor (semiconductor chip) 3 control circuit component 4 external lead-out terminal 5 resin case 5 a partition wall 6 heat-dissipating metal plate 7 bonding wire 8 wiring conductor

Claims (4)

(57) [Claims] A metal case is mounted on a resin case, a semiconductor chip mounted on the metal insulating substrate, a control circuit component, and an external lead-out terminal, and wire bonding is performed between the semiconductor chip and the control circuit component and the external lead-out terminal. In the semiconductor device connected internally, a partition wall that covers the upper surface area of the metal insulating substrate without the mounting area of the semiconductor chip is provided at a middle position in the case, and an external lead terminal is provided on the upper surface side of the partition wall. A semiconductor device comprising a control circuit component and a wiring conductor thereof. 2. The semiconductor device according to claim 1, wherein the external lead-out terminal and the wiring conductor of the control circuit component are inserted into a partition wall of the case and are integrally formed. 3. A semiconductor device according to claim 1, wherein a semiconductor chip is mounted on a metal insulating substrate via a heat-dissipating metal plate while a metal foil is adhered over the entire surface of the metal insulating substrate. Semiconductor device. 4. The semiconductor device according to claim 3, wherein the heat-dissipating metal plate covers substantially the entire surface of the metal foil of the metal insulating substrate and is thermally conductively bonded.