JPH06204366A - Bare chip heat dissipating pedestal - Google Patents

Abstract

PURPOSE:To enhance a semiconductor device in manufacturing yield and reliability by a method wherein a short circuit is prevented from occurring between a heat dissipating pedestal and a wire due to the wire in hanging, and a bare chip is enhanced in accuracy of mounting position. CONSTITUTION:A heat releasing pedestal 2 is of such a rotation-symmetrical structure that first slopes 2b are provided between a bare chip mounting face 2a and side faces 2e of a heat dissipating pedestal 2, a second slope 2c is provided between the adjacent first slopes 2b, a second side face 2d is provided between the adjacent side faces 2e, the heat dissipating pedestal 2 is mounted on a pedestal mounting electrode 5 on a hybrid substrate of thick film, and a chip transistor 1 mounted on the bare chip mounting face 2a is connected to a wire connection electrode 4 with a wire 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bare chip heat dissipation pedestal, and more particularly to a bare chip heat dissipation pedestal used in a semiconductor element such as a power transistor which consumes a large amount of power.

[0002]

2. Description of the Related Art FIG. 5 is a perspective view showing a conventional heat dissipation base of a bare chip mounted on a frame of a package or a thick film hybrid substrate and used in a power transistor. In the drawing, 1 is a bare chip transistor and 2 is a bare chip transistor. A rectangular parallelepiped heat dissipation base, 2a is a bare chip mounting surface, 3 is a wire, 4 is a wire connection electrode formed on a thick film hybrid substrate, and 5 is a heat dissipation base mounted on the thick film hybrid substrate. Electrodes (hereinafter referred to as pedestal mounting electrodes).

Next, the structure of the heat-dissipating pedestal of the bare chip of this conventional example will be described by taking the case where the semiconductor element is a transistor as an example. For transistors that consume large amounts of power,
When a bare chip of a transistor is mounted on a dedicated package or a thick film hybrid substrate, as shown in FIG. 5, the collector electrode corresponding to the back surface of the bare chip transistor 1 is fixed on the bare chip mounting surface 2a of the heat dissipation pedestal 2 for heat dissipation. The pedestal 2 is mounted on the pedestal mounting electrode 5 of the dedicated package or thick film hybrid substrate, and the emitter and the base electrode of the bare chip transistor 1 mounted on the radiating pedestal 2 and the external wire connection electrode 4 are made conductive. They are connected by a good wire 3.

[0004]

Since the conventional heat dissipation pedestal of the bare chip is configured as described above, the wire 3 and the heat dissipation pedestal 2 are the bare chip mounting surface 2a and the side surface of the heat dissipation pedestal 2. Are closest to each other at the corners made by, and during the transportation in the manufacturing process or when applying a bare chip protective film,
If the wire 3 connecting the bare chip 1 and the external electrode 4 hangs down, this may come into contact with the peripheral edge of the heat-dissipating pedestal, causing a short circuit. If so, there was a problem such as needing rework. Further, when the size of the bare chip to be mounted is significantly smaller than that of the radiating base, there is a problem that the positioning accuracy of mounting the bare chip becomes poor. Further, in pattern design of a thick film hybrid substrate or the like, there is a problem that the shape of the radiating pedestal restricts when determining the connecting direction of the wire.

The present invention has been made to solve the above problems, and reduces the short circuit between the wire and the radiating base even when the wire connecting the bare chip and the external electrode hangs down. This aims to obtain a heat dissipation pedestal that can reduce rework during the manufacturing process, and also aims to obtain a heat dissipation pedestal that can improve the positioning accuracy of bare chips and improve the manufacturing yield. Furthermore, it is an object of the present invention to obtain a radiating base for a bare chip that does not hinder the determination of the wire connection direction in the pattern design of a thick film hybrid substrate or the like.

[0006]

The heat dissipation base of the bare chip according to the present invention has a substantially rectangular parallelepiped shape, and is formed on the side wall of the heat dissipation base between the surface on which the bare chip is mounted and the side surface. The structure has at least one set of inclined surfaces facing each other.

Further, the heat dissipation base of the bare chip according to the present invention has a substantially rectangular parallelepiped shape, and the side wall of the heat dissipation base has a first inclined surface formed between the surface on which the bare chip is mounted and the side surface. And a second inclined surface formed between the adjacent first inclined surfaces and a second side surface formed between the adjacent side surfaces, thereby forming a rotationally symmetric structure.

Furthermore, the heat dissipation pedestal of the bare chip according to the present invention has a substantially cylindrical shape, and has an inverted mortar-like structure by providing an inclined surface between the surface on which the bare chip is mounted and the side surface. . Further, the heat dissipation base of the bare chip according to the present invention has a truncated cone shape, and the bare chip is mounted on the flattened upper surface of this truncated cone.

[0009]

In the present invention, at least one inclined surface is provided between the bare chip mounting surface and the side surface of the heat dissipation pedestal having a substantially rectangular parallelepiped shape so as to face each other. Since the pedestal mounting electrodes on both sides of the frame or thick-film hybrid substrate are sandwiched by the pedestal mounting electrodes, the wires are placed on the pedestal mounting electrodes so that shorts between the wires and the radiating pedestal can be avoided. This can reduce the number of repairs during the manufacturing process and improve the reliability of the manufacturing process.

Further, according to the present invention, the first inclined surface is provided between the bare chip mounting surface and the side surface of the substantially rectangular parallelepiped heat dissipation pedestal, and the second inclined surface is provided between the adjacent first inclined surfaces. Since the second side surface is provided between adjacent side surfaces and has a rotationally symmetric structure, the mounting surface on which the bare chip is mounted is narrowed, and thereby the positioning accuracy of the bare chip can be increased, and the manufacturing yield and The reliability can be improved, and the wire connection in the mounting direction of the heat dissipation base can be eliminated.

Further, according to the present invention, since the heat dissipating pedestal having a substantially columnar shape and the conical heat dissipating pedestal having an inclined surface at the periphery of the bare chip mounting surface, the mounting for mounting the bare chip is further performed. The surface becomes narrower, which can improve the positioning accuracy of the bare chip.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. Example 1. FIG. 1 is a view for explaining a heat dissipation base of a bare chip according to a first embodiment of the present invention.
1 is a plan view of the heat dissipation pedestal, FIG. 1B is a side view of the heat dissipation pedestal, and FIG. 1C is a perspective view of the heat dissipation pedestal mounted on the pedestal mounting electrode on the thick film hybrid substrate. In these figures, the same reference numerals as those in FIG. 5 denote the same or corresponding parts, 2a denotes a bare chip mounting surface of the heat dissipation pedestal 2 and 2b denotes a bare chip mounting surface 2a and a side surface of the conventional heat dissipation pedestal 2 shown in FIG. The inclined surfaces 2b are formed at a reduced angle, and one set of the inclined surfaces 2b is provided on both sides of the bare chip mounting surface 2a.

As described above, in this embodiment, the inclined surface 2b is provided on the side wall of the heat dissipation base 2 without changing the size of the heat dissipation base.
Are provided opposite to each other, and the radiating base 2 is provided on both sides of the pedestal mounting electrode 5 on the thick film hybrid substrate with the inclined surface 2b of the radiating pedestal 2 interposed therebetween. Bare chip transistor 1 mounted on the pedestal mounting electrode 5 toward the side and mounted on the bare chip mounting surface 2a by the wire 3.
Since the wire connection electrode 4 is connected to the wire connection electrode 4, the distance from the wire 3 to the inclined surface 2b can be increased without reducing the heat dissipation of the heat dissipation base. Therefore, during transportation in the manufacturing process or when applying a bare chip protective film, it is possible to reduce the risk of short circuit due to contact with the corners of the heat dissipation pedestal due to the wire dripping, which reduces rework during the manufacturing process. Therefore, there is an effect that reliability in the manufacturing process can be improved.

Example 2. 2A and 2B are views for explaining a heat dissipation pedestal of a bare chip according to a second embodiment of the present invention, FIG. 2A is a plan view of the heat dissipation pedestal, and FIG. 2B is a side view of the heat dissipation pedestal. FIG. 2 (c) is a perspective view of the heat dissipation pedestal mounted on the pedestal mounting electrode on the thick film hybrid substrate. In these figures, the same reference numerals as those in FIG. 5 denote the same or corresponding parts, 2 is a heat radiating pedestal having a rotationally symmetrical shape by dropping the corners of the conventional heat radiating pedestal shown in FIG. 2 bare chip mounting surface, 2b bare chip mounting surface 2
A first inclined surface 2c formed between a and the side surface 2e is a second inclined surface formed between the adjacent first inclined surfaces 2b, and 2d is formed between the adjacent side surfaces 2e. It is the second aspect.

As described above, in the heat dissipation base of the second embodiment,
Since the side wall of the heat dissipation pedestal 2 is chamfered to have a rotationally symmetrical structure, the same effect as that of the first embodiment can be obtained, and the heat dissipation pedestal is mounted on the pedestal mounting electrode. There is no restriction on the direction. Further, since the entire area of the edge of the bare chip mounting surface is chamfered, the bare chip mounting surface is narrowed, so that the positioning accuracy of the bare chip is improved, and the manufacturing yield and the reliability in the manufacturing process can be improved. is there.

Embodiment 3. 3A and 3B are views for explaining a heat dissipation pedestal of a bare chip according to a third embodiment of the present invention, FIG. 3A is a plan view of the heat dissipation pedestal, and FIG. 3B is a side view of the heat dissipation pedestal. FIG. 3 (c) is a perspective view of the heat dissipation pedestal mounted on the pedestal mounting electrode on the thick film hybrid substrate. In these drawings, the same reference numerals as those in FIG. 5 indicate the same or corresponding portions, 2 is a columnar heat dissipation pedestal whose upper periphery is chamfered, 2a is a bare chip mounting surface, and 2b is an inclined surface.

In the heat dissipating pedestal of the third embodiment as described above,
Since the periphery of the bare chip mounting surface of the heat dissipation pedestal is chamfered and the inclined surface is provided around the chamfered surface, the same effect as that of the second embodiment can be obtained.

Example 4. 4A and 4B are views for explaining a heat dissipation pedestal of a bare chip according to a fourth embodiment of the present invention. FIG. 4A is a plan view of the heat dissipation pedestal, and FIG. 4B is a side view of the heat dissipation pedestal. FIG. 4 (c) is a perspective view of the heat dissipation pedestal mounted on the pedestal mounting electrode on the thick film hybrid substrate. In these figures, the same reference numerals as those in FIG. 5 indicate the same or corresponding portions, 2 is a truncated cone-shaped heat radiating pedestal, which has the same height and bottom area as those in the third embodiment, and 2a is a bare chip mounted The surface 2b is an inclined surface.

In the heat dissipating pedestal of the fourth embodiment as described above,
Since it has the shape of a truncated cone, and the bare chip transistor 1 is mounted on the upper surface of this truncated cone, the bare chip mounting positioning accuracy can be improved as in the third embodiment.

It should be noted that, instead of the thick film hybrid substrate, the heat dissipation pedestal may be mounted on the frame of the dedicated package.
It goes without saying that the same effects as those of Examples 1, 2, 3 and 4 are obtained.

[0021]

As described above, according to the heat dissipating pedestal of the bare chip of the present invention, the size of the heat dissipating pedestal having a substantially rectangular parallelepiped shape is not changed, and the tilt is provided between the surface on which the bare chip is mounted and the side surface thereof. Since the structure is such that at least one pair of surfaces are provided facing each other, the distance between the wire and the heat radiation pedestal is increased without reducing the heat radiation performance of the heat radiation pedestal, and it is difficult for the wire to contact the heat radiation pedestal. Therefore, it is possible to reduce short-circuiting between the wire and the heat radiation pedestal, reduce the need for rework during the manufacturing process, and improve the reliability in the manufacturing process.

Further, since the periphery of the side wall of the heat dissipation pedestal is chamfered to have a rotationally symmetrical structure, the mounting surface on which the bare chip is mounted is narrowed, and thereby the positioning accuracy of the bare chip can be improved and the manufacturing The yield and reliability can be improved, and there is an effect that the mounting direction of the heat radiation pedestal is not restricted.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a heat dissipation base of a bare chip according to a first embodiment of the present invention.

FIG. 2 is a view for explaining a heat dissipation base of a bare chip according to a second embodiment of the present invention.

FIG. 3 is a diagram for explaining a heat dissipation base of a bare chip according to a third embodiment of the present invention.

FIG. 4 is a view for explaining a heat dissipation base of a bare chip according to a fourth embodiment of the present invention.

FIG. 5 is a perspective view showing a conventional radiating base of a bare chip.

[Explanation of symbols]

 1 Bare Chip Transistor 2 Heat Dissipation Pedestal 2a Bare Chip Mounting Surface 2b Sloping Surface 2c Sloping Surface 2d Side 2e Side 3 Wire 4 Wire Connecting Electrode 5 Pedestal Mounting Electrode

Claims (4)

[Claims] 1. A wire connection for mounting a bare chip on a frame of a package or a pedestal for mounting heat dissipation on a thick film hybrid substrate, and for forming a wire on both sides of the electrode for mounting the pedestal for heat dissipation. In the heat dissipation pedestal formed by connecting the electrode and the bare chip with a wire, the pedestal has a substantially rectangular parallelepiped shape, and its side wall is provided with an inclined surface formed between the surface on which the bare chip is mounted and the side surface. A bare chip heat-dissipating pedestal having a structure having at least one set. 2. A bare chip is mounted on a frame of a package or a thick film hybrid substrate and is mounted on electrodes for mounting a heat-dissipating pedestal, and for wire connection formed on both sides of the electrode for mounting the heat-dissipating pedestal. A heat-dissipating pedestal formed by connecting an electrode and the bare chip with a wire has a substantially rectangular parallelepiped shape, and has a first inclined surface formed on a side wall thereof between a surface on which the bare chip is mounted and a side surface. ,
It is characterized in that it has a second inclined surface formed between the adjacent first inclined surfaces and a second side surface formed between the adjacent side surfaces, and has a rotationally symmetrical shape structure. Base for heat dissipation of bare chip. 3. A wire chip for mounting a bare chip, mounted on a radiating base mounting electrode on a frame of a package or a thick film hybrid substrate, and for forming a wire connection formed on both sides of the radiating base mounting electrode. In the heat dissipation pedestal formed by connecting the electrode and the bare chip with a wire, the pedestal has a substantially columnar shape, and an inclined surface is formed between the surface on which the bare chip is mounted and the side surface. Heat dissipation pedestal for bare chips, which is characterized by 4. A wire connection for mounting a bare chip on a frame of a package or a pedestal mounting electrode for heat dissipation on a thick film hybrid substrate, and for connecting wires formed on both sides of the pedestal mounting electrode for heat dissipation. A radiating base for a heat dissipation, which is formed by connecting an electrode and the bare chip with a wire, and has a truncated cone shape, and the bare chip is mounted on an upper surface of the truncated cone.