JPH0442925Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a power semiconductor device, and more particularly to a power semiconductor device including a plurality of semiconductor chips and a heat spreader on which these semiconductor chips are mounted.

<Summary of the invention> The invention is a power semiconductor device in which a plurality of semiconductor chips are mounted on a substrate via heat spreaders, in which the heat spreaders are electrically connected in common. In addition to being integrated, a groove is provided on the lower surface of the connection part of the heat spreader, and a part of the wiring pattern on the board is formed through the groove corresponding part, making it possible to perform three-dimensional wiring and secure the necessary heat dissipation area. It is possible to achieve high-density packaging while reducing the size of the power semiconductor device.

<Prior Art> FIG. 3 is a sectional view showing the internal structure of a conventional power semiconductor device, and FIG. 4 is a top view of the same essential parts (excluding the semiconductor chip).

Inside the power semiconductor device, there is provided a circuit board 20 made of a substrate 11 made of aluminum or the like, on which an insulating layer 12 is formed, and on which a predetermined wiring pattern 13 is formed. This circuit board 2
0, there are input/output terminals 14 and a semiconductor chip 16.
It is equipped with a heat spreader 15 equipped with. In this example, the semiconductor chip 16 is a power transistor. semiconductor chip 16
The upper surface electrode (emitter base) and the wiring pattern 13 are connected by bonding wires 17, respectively. Further, the back electrode (collector) is connected via the heat spreader 15 to a wiring pattern 13 formed overlappingly below the heat spreader 15.
connected to. Further, an outer frame 18 forming a part of the outer shell of the power semiconductor device is provided around the circuit board 20, and a container formed by the circuit board 20 and the outer frame 18 protects internal components. A resin 19 is filled for this purpose.

In FIG. 4, a is a pattern for connecting the collector of the upper transistor, b is a pattern for connecting the base of the upper transistor, g is a pattern for connecting the emitter of the upper transistor and the collector of the lower transistor, d is a pattern for connecting the emitter of the lower transistor, e is a pattern for connecting the base of the lower stage transistor.

In addition, in the figure, the ○ mark indicates the mounting position of the terminal 14.

Moreover, the circuit diagram is shown in FIG.

<Problems to be solved by the invention> However, in the above-mentioned conventional wiring structure, the collector terminal position of the upper stage transistor (marked with a circle on pattern g), which is located in the center of the device, is attempted to be located in the periphery of the device. In this case, it is necessary to process the terminal into a special shape and use it as a jumper terminal, or to form a circuit by detouring the wiring pattern 13 on the substrate 20 to the outer peripheral portion of the heat spreader 15 in a plane.

Therefore, in any case, problems arise in these methods, such as the shape of the terminal becomes complicated or the area of the substrate becomes large.

The present invention was developed in view of these circumstances, and its purpose is to facilitate the placement of output terminals around the device, secure the required heat dissipation area of the heat spreader, and achieve high efficiency. An object of the present invention is to provide a power semiconductor device that can be densely packaged.

<Means for Solving the Problems> The present invention provides a power semiconductor device in which a plurality of semiconductor chips are mounted on a circuit board via a heat spreader. The heat spreader is characterized in that the spreaders are connected and integrated, a groove is provided on the lower surface of the connection part of the heat spreader, and a part of the wiring pattern on the substrate is formed through the corresponding part of the groove.

<Function> The present invention uses a heat spreader with the above structure, and forms a part of the wiring pattern on the board to correspond to the grooves of the heat spreader, thereby enabling three-dimensional wiring and connecting the output terminals. can be easily placed around the circuit board. In addition, high-density packaging can be achieved while ensuring the necessary heat dissipation area of the heat spreader, thereby making it possible to downsize the device.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing the internal structure of an embodiment of a power semiconductor device according to the present invention, and FIG. 2 is a top view of the same essential parts (excluding the semiconductor chip).

In this embodiment, a structure in which semiconductor chips are arranged in two stages, upper and lower, will be described, but the arrangement of the chips is not limited to this.

As shown in FIG. 1, the power semiconductor device of this example is a circuit board in which an insulating layer 2 is formed on the surface of a substrate 1 made of aluminum or the like, and a wiring pattern 3 in the shape shown in FIG. 2 is further formed thereon. It is equipped with 10.
Note that the ○ mark indicates the mounting position of the output terminal 4. Furthermore, an output terminal 4 is attached to the circuit board 10, a semiconductor chip 6 is mounted via heat spreaders 5, 5', and a bonding wire 7 connects the top surface of the semiconductor chip 6 and the electrode pattern 3. Thereafter, an outer frame 8 is provided around the circuit board 10, and a resin 9 is filled in the outer frame.

In this example, the semiconductor chip 6 is a power transistor, and the heat spreader 5 arranged on the upper stage of the circuit board 10 connects adjacent heat spreader parts 5a so that the collectors of the upper stage transistors are commonly connected. Connected and integrated,
A groove 5c is provided on the lower surface of the connecting portion 5b, so that when the heat spreader 5 is joined to the circuit board 10, a part of the wiring pattern 3 of the circuit board 10 is located in a corresponding part of the groove 5c. It is configured.

In FIG. 2, the collectors of the upper stage transistors (not shown) are commonly connected and guided to the terminal attachment position of wiring pattern a by means of a heat spreader 5 which is connected and integrated. b is a pattern for connecting the bases of each transistor in the upper stage.
c is a pattern for connecting the emitter of the upper transistor and the base of the lower transistor (corresponding to g in FIG. 4), and connects the collector of each lower transistor (not shown) to each heat spreader 5'.
This wiring pattern c
Accordingly, the integrated heat spreader 5
It is led to the emitter terminal mounting position of the upper stage transistor through the corresponding part of the groove 5c. Then, the output terminal 4 dedicated to the emitter of the upper stage transistor is fixed at the position marked with a circle in pattern c. d is a pattern for connecting the emitter of the lower transistor, and e is a pattern for connecting the base of the lower transistor. Further, f is a pattern for connecting the collector of the lower transistor which is separately provided, and the output terminal 4 dedicated to the collector of the lower transistor is fixed.

The present invention enables three-dimensional wiring by using the heat spreader 5 with the above structure, and the terminal position (pattern g), which was placed in the center of the device in the conventional example (see Figure 4) (○ marked part) can be easily placed around the device.
In addition, high-density mounting is possible while ensuring the necessary heat dissipation area for the heat spreader.

<Effects of the invention> As described above, according to the invention, the structure is extremely simple, the output terminals can be easily placed around the device, and the necessary heat dissipation area of the heat spreader can be secured. Since it is possible to implement high-density packaging at the same time, it is possible to downsize the device.

[Brief explanation of the drawing]

Figure 1 is a side sectional view of one embodiment of the present invention, Figure 2 is a top view of the same embodiment before chip mounting, and Figure 3 is a side sectional view of an embodiment of the present invention.
4 is a top view of the conventional example before chip mounting, and FIG. 5 is an equivalent circuit diagram of FIG. 4. 10... Circuit board, 3... Electrode pattern, 4...
...Input/output terminal, 5...Heat spreader section, 5
b...Connecting portion, 5c...Groove, 6...Semiconductor chip.

Claims (1)

[Scope of utility model registration request] In a power semiconductor device in which a plurality of semiconductor chips are mounted on a substrate via heat spreaders, the heat spreaders that are electrically connected in common are connected and integrated, and the heat spreaders are 1. A power semiconductor device characterized in that a groove is provided on the lower surface of a connecting portion of a semiconductor device, and a part of a wiring pattern on a substrate is formed through a corresponding portion of the groove.