JPH0617318Y2 - Semiconductor device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention discloses that a planar semiconductor chip and a mesa semiconductor chip are fixed on a metal substrate in a container formed of a metal substrate and a side wall made of an insulating material. And a resin-sealed semiconductor device.

[Conventional technology]

As a semiconductor device as described above, there is, for example, a power transistor module of an equivalent circuit in which a diode for power supply rectification is added to the power transistor module of the bridge structure shown in FIG. 4, and its structure is shown in FIG. As shown in the cross-sectional view, the power transistor chip 3 and the diode chip 4 are mounted on the copper plate 1 in the container, which is composed of the copper plate 1 also serving as the substrate and the heat dissipation plate and the side wall 2 formed of an insulating resin. Attached (one each shown in the figure),
Although not shown, it is generally known that an external lead-out terminal is attached, necessary wiring is made, the gel 5 is filled, and the gel 5 is sealed with an epoxy resin 6.

[Problems to be Solved by the Invention] The resin encapsulation of such a semiconductor device covers the power transistor chip and the diode chip with gel as described above,
It is made by injecting an epoxy resin onto it and curing it. In recent years, there has been a strong demand for higher breakdown voltage, higher current, and higher reliability of power transistor modules. Planar type transistor chips have been adopted to achieve this, but directly on the planar type transistor chips. If epoxy resin is injected and cured and then sealed, the transistor chip may be destroyed by the stress of the epoxy resin during curing and the stress due to thermal expansion and contraction of the epoxy resin when using a semiconductor device. This is to alleviate the stress on the transistor chip and protect the transistor chip. However, when the diode chip used at the same time is a glass-passivated mesa-shaped chip, the problem that the reverse current of the diode chip increases by covering with a gel occurs. Conventionally, in order to avoid such a problem, a planar chip must be used as a diode chip housed in the same container as the planar transistor chip, and a mesa chip cannot be used.

As described above, in the semiconductor device having the conventional structure, the planar semiconductor chip and the mesa semiconductor chip cannot be housed in the same container without deteriorating the characteristics and reliability of the respective chips. When one semiconductor chip requires a planar type in terms of desired performance, the other semiconductor chip must also have a planar type. Since the planar type chip is more expensive than the mesa type chip, there has been a problem that the price of the semiconductor device is increased accordingly.

This invention has been made in view of the above points,
An object of the present invention is to provide a highly reliable semiconductor device having a structure in which a planar semiconductor chip and a mesa semiconductor chip can be housed in the same container without degrading the characteristics and reliability of each.

[Means for Solving the Problems]

In order to achieve the above object, according to the present invention, a planar semiconductor chip and a mesa semiconductor chip are fixed on a metal substrate in a container composed of a metal substrate and a side wall made of an insulating material. In a sealed semiconductor device, a region in which a planar semiconductor chip is fixed in a container and a region in which a mesa semiconductor chip is fixed are partitioned by an inner wall, and a region where the planar semiconductor chip is fixed Is a semiconductor device having a structure in which the planar type semiconductor chip is sealed with a sealing resin from above the gel and the region to which the mesa type semiconductor chip is fixed is sealed with the sealing resin alone.

[Action]

By partitioning the region to which the planar semiconductor chip is fixed and the region to which the mesa semiconductor chip is fixed in the container of the semiconductor device by the inner wall, resin sealing of each region can be performed individually, and the planar semiconductor The area where the chip is fixed is covered with gel and then sealed with a sealing resin, and the area where the mesa-type semiconductor chip is fixed is sealed with the sealing resin alone without using a gel. The mesa-shaped semiconductor chip can be a semiconductor device that is housed in the same container without deteriorating the characteristics and reliability of each.

〔Example〕

FIG. 1 is a sectional view of an embodiment in which the present invention is applied to the semiconductor device having the equivalent circuit shown in FIG. 4, and the same parts as those in FIG. There is. In FIG. 1, a planar type power transistor chip 3 and a mesa type diode chip 4 are provided on a copper plate 1 in a container composed of a copper plate 1 as a substrate and a side wall 2 formed of an insulating resin. They are brazed (only one is shown in the figure), and the brazed region of the power transistor chip 3 and the brazed region of the diode chip 4 are separated by the inner wall 7 which is formed integrally with the side wall 2. Although not shown in the drawing, external lead-out terminals are soldered on the copper plate 1 and required wiring is made, and gel 5 is injected into the brazed region of the power transistor chip and epoxy resin is applied from above. 6 and the brazed area of the diode chip is sealed with epoxy resin alone.

FIG. 3 shows the side wall 2 in which the inner wall 7 is integrally formed of the same material, and FIG. 3 (a) is a side view and FIG. 3 (b) is a plan view.

In the assembly of the conventional semiconductor device shown in FIG. 2, after the power transistor chip 3 and the diode chip 4 are brazed on the copper plate 1 and external lead terminals (not shown) are soldered to perform the required wiring, Although the side wall is fixed on the copper plate 1, the gel 5 is injected, and the epoxy resin is injected on the copper 5 to cure and seal the same, the embodiment also shows a process as shown in FIG. If the side wall 2 in which the inner wall 7 is formed integrally is used, it can be assembled in the same process as the conventional one, and the number of assembling steps does not change.

In the embodiment, since the planar type power transistor chip is protected by the gel, the planar type power transistor chip is not destroyed by the thermal stress of the epoxy resin, and the gel is formed in the brazed area of the mesa type diode chip. Since it is not used, the reverse current does not increase, and a semiconductor device with good characteristics and high reliability can be obtained.

[Effect of device]

According to this invention, the region in which the planar semiconductor chip is fixed and the region in which the mesa semiconductor chip is fixed in the same container of the semiconductor device are partitioned by the inner wall, and the region where the planar semiconductor chip is fixed is a gel. Is injected and the chip is covered with gel and then sealed with a sealing resin, and the region to which the mesa semiconductor chip is fixed is sealed with the sealing resin alone. With such a structure, it is possible to obtain a highly reliable semiconductor device in which the planar semiconductor chip and the mesa semiconductor chip are housed in the same container without deteriorating their respective characteristics and reliability.

Thus, of the semiconductor chips that make up the semiconductor device,
As for the mesa-type chip that can obtain the required performance, it becomes possible to use the mesa-type chip instead of the planar-type chip, and the cost of the semiconductor device can be reduced. Further, it becomes possible to manufacture a semiconductor device in which a circuit that can be efficiently configured by using a planar semiconductor chip and a mesa semiconductor chip together is housed in one container, and it is possible to expand the field of application of the semiconductor device.

[Brief description of drawings]

1 is a conceptual sectional view showing an embodiment of a semiconductor device according to the present invention, FIG. 2 is a conceptual sectional view showing an example of a conventional semiconductor device, and FIG. 3 is provided with an inner wall according to the present invention. Fig. 3 (a) shows a side view,
FIG. 4B is a plan view and FIG. 4 is an equivalent circuit diagram of an example of a semiconductor device according to the present invention. 1 ... Copper plate, 2 ... Side wall, 3 ... Power transistor chip, 4 ... Diode chip, 5 ... Gel, 6 ... Epoxy resin, 7 ... Middle wall.

Claims (1)

[Scope of utility model registration request] 1. A semiconductor device in which a planar semiconductor chip and a mesa semiconductor chip are fixed and resin-sealed on the metal substrate in a container formed of a metal substrate and a side wall made of an insulating material. The region to which the planar semiconductor chip is fixed is separated from the region to which the mesa semiconductor chip is fixed by the inner wall, and the region where the planar semiconductor chip is fixed is on the gel covering the planar semiconductor chip. Is sealed with a sealing resin, and the region to which the mesa-shaped semiconductor chip is fixed is sealed with the sealing resin alone.