JPH0691170B2 - Base metal plate for semiconductor devices - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a semiconductor device, and more particularly to a base metal of a semiconductor device in which a semiconductor element is mounted on a base metal plate via a ceramic insulating plate and resin-sealed. It is about boards.

[Conventional technology]

FIG. 2 shows this conventional semiconductor device of this type. In the figure, 1 is a housing, 2 is an external terminal for transmitting and receiving an electrical signal from the outside, 3 is a printed circuit board for connecting between circuits, 4 Is a semiconductor component mounted on the printed circuit board 5,
Is a semiconductor element connected to the printed circuit board 3, and 6 is a housing 1
Is a base metal plate fixed to the substrate, 7 is a ceramic plate inserted between the semiconductor element 5 and the base metal plate 6 to insulate them, and 8 is a molding resin for covering the circuit components 2 to 5 and electrically insulating them. .

In the base metal plate of such a semiconductor device, insulation from the circuit components 2 to 5 is performed from the semiconductor element 5 to the ceramic plate 7.
Since it has a weak insulation effect due to the distance to the end surface of the ceramic plate and the distance obtained by adding the thickness of the ceramic plate 7, the whole is covered with the molding resin 8 to enhance the insulation effect.

[Problems to be Solved by the Invention]

Since the base metal plate of the conventional semiconductor device is configured as described above, the adhesive force between the molding resin 8 and the ceramic plate 7 is weak, and the expansion and contraction rates of the resin 8 are the ceramic plate 7, the base metal plate. Therefore, unlike that of 6, low temperature,
Due to repeated high temperatures, there is a problem that a gap is formed between the mold resin 8 and the ceramic plate 7 and the metal plate 5 to cause discharge between the semiconductor element 5 and the metal plate 6.

In another conventional semiconductor device of Japanese Utility Model Laid-Open No. 56-19039 shown in FIG. 3, the distance from the peripheral edge of the semiconductor element to the contact point between the metal plate 21 of the insulating plate 22 and the surface of the insulating plate 22 is increased. , The purpose is to increase the dielectric strength of the interface between the filling resin and the insulating plate 22, and the edges of the insulating plate 22 all overhang the floating groove 28 around the bottom of the insulating plate to increase the corners. Therefore, there is a weakness in the strength of the filling resin, and the adhesive strength between the insulating plate 22 and the metal plate 21 is reduced. There is a problem that it is not preferable from the viewpoint of improvement.

Further, in still another conventional semiconductor device disclosed in JP-A-56-147453 shown in FIGS. 4 (a) and 4 (b), a resin 31 for coating a semiconductor element mounting metal plate 32 on which a semiconductor element 33 is mounted is used. Is an invention for improving the adhesive strength of a circular groove
The main purpose is to increase the adhesion area by providing 36 (or annular protrusion), thereby increasing the peel strength of the adhesion surface, and secondarily to the exposed end of the semiconductor element mounting metal plate 32 and the semiconductor element. The purpose is to increase the interfacial distance with the 33 and improve the moisture resistance, but there is a problem that the effect beyond the increase of the adhesive area cannot be expected.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a base metal plate of a semiconductor device capable of increasing the adhesive force with a molding resin and increasing the insulating effect.

[Means for Solving the Problems]

A base metal plate of a semiconductor device according to the present invention mounts a semiconductor element via a ceramic plate, forms a groove along the peripheral edge of the ceramic plate, and forms the base surrounded by the groove. The flat portion of the bonding portion of the metal plate with the ceramic plate is made to substantially match the shape of the bonding surface of the ceramic plate.

[Action]

In the present invention, since the concave groove is formed on the base metal plate along the peripheral edge of the ceramic plate on the base metal plate, the mold resin is hard to enter into the concave groove of the metal plate, and the adhesive force between the mold resin and the metal plate increases. In addition, since one end face of the ceramic plate and the side face of the concave groove form one adhesive face perpendicular to the face of the metal plate, the peel strength of the adhesive force between the ceramic plate and the metal plate is reinforced by the mold resin. be able to.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. First
The figure shows a semiconductor device according to an embodiment of the present invention, in which 1 is a housing (side wall), 2 is an external terminal for transmitting and receiving an electric signal from the outside, and 3 is a printed circuit board for connecting circuits. Reference numeral 4 denotes a semiconductor component mounted on the printed circuit board 3, 5 denotes a semiconductor element connected to the printed circuit board 3, 6
Is a base metal plate fixed to the housing 1, 7 is a semiconductor element 5
And a metal plate 6, which are inserted between the metal plate 6 and the ceramic plate to insulate them, 8 is a molding resin that covers and electrically insulates the circuit components 2 to 5, and 11 is a metal plate 6 along the periphery of the ceramic plate 7. It is a formed groove.

Next, the function and effect will be described.

In the apparatus of this embodiment, the mold resin 8 injected into the housing 1
Flows into the concave groove formed in the metal plate 6, which not only increases the adhesive force between the mold resin 8 and the metal plate 6, but also the end portion of the bonded portion between the ceramic plate 7 and the metal plate 6 is soldered. Since the voids are filled with an adhesive such as to form a smooth surface, the surface substantially perpendicular to the interface between the ceramic plate 7 and the metal plate 6 becomes the bonding surface with the mold resin, and the ceramic plate 7 and the metal plate 6 6 can be reinforced against peeling.

Therefore, even if expansion and contraction are repeated due to temperature changes,
There is no gap between the mold resin 8 and the ceramic plate 7 and the metal plate 6, and no electric discharge occurs between the mold resin 8 and the metal plate 6 of the semiconductor element 5.

〔The invention's effect〕

As described above, according to the base metal plate of the semiconductor device of the present invention, since the groove is formed on the metal plate along the peripheral edge of the ceramic plate, the adhesive force between the mold resin and the metal plate can be increased. Therefore, there is an effect that the insulating effect can be increased.

[Brief description of drawings]

1 is a sectional side view showing a semiconductor device according to an embodiment of the present invention, FIG. 2 is a sectional side view showing a conventional semiconductor device, and FIG. 3 is a sectional side view showing another conventional semiconductor device.
4 (a) and 4 (b) are a plan view and a sectional side view showing still another conventional semiconductor device. In the figure, 1 is a housing, 2 is an external terminal, 3 is a printed circuit board, 4
Is a semiconductor component, 5 is a semiconductor element, 6 is a metal plate, 7 is a ceramic plate, 8 is a mold resin, and 11 is a concave groove of the metal plate. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A semiconductor element is mounted on a base metal plate via an insulating ceramic plate, a peripheral wall is provided on the base metal plate so as to surround the periphery, and a mold resin is filled in the peripheral wall. In the base metal plate of the semiconductor device, a groove is formed along the periphery of the ceramic plate on the bonding surface of the ceramic plate of the base metal plate, and the base metal plate is surrounded by the groove. A base metal plate for a semiconductor device, wherein a bonding portion with the ceramic plate has substantially the same shape as a bonding surface of the ceramic plate.