JPH06151699A - Semiconductor device - Google Patents

Abstract

(57) [Abstract] [Purpose] Three semiconductor chips are commonly connected to the electrodes on one side, and the electrodes on the other side are connected to lead terminals respectively to improve heat dissipation from the semiconductor device chip and reduce the number of parts. , Easy to assemble. [Structure] One electrode of each chip is fixed on one surface of a copper substrate, the lead portion of the lead frame is brazed to the other electrode, the other surface of the substrate and the end of the lead portion are exposed, and molded with resin. To do. If the other surface of the substrate is attached in close contact with the cooling body, good heat dissipation is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a structure in which one electrode of three or more semiconductor elements each having electrodes on both sides is connected to each other and a terminal conductor individually connected to the other electrode is drawn to the outside. The present invention relates to a semiconductor device.

[0002]

2. Description of the Related Art For example, as shown in FIG. 3, a semiconductor in which three silicon surge absorbers 21 having a bidirectional characteristic are connected to each other when a voltage higher than a certain voltage is applied in any direction. Figure 2 when assembling the device
The structure shown in is known. That is, an electrode on one surface of the silicon surge absorber chip 1 is brazed on the head of one lead terminal 31, and a connecting plate 34 is brazed on the electrode on the other surface of the chip. Then, the electrodes on one surface of the other silicon surge absorber chips 2 and 3 are brazed. After the electrodes on the other surface of the chips 2 and 3 are connected to the heads of the lead terminals 32 and 33, respectively, using the connecting pieces 35, the end portions of the lead terminals 31, 32 and 33 are exposed to expose the resin 4
To mold.

[0003]

However, the structure shown in FIG. 2 has the following drawbacks. (1) Since the three chips 1, 2, 3 are surrounded by the resin 4 and heat is radiated only through the lead terminals 31, 32, 33, it is difficult to cool and the cooling is not uniform.

(2) Since the three chips 1, 2, 3 are separated on two planes, the assembly is complicated. (3) In addition to the three lead terminals 31, 32, 33, the connection plates 34, 2
Since the individual connecting pieces 35 are required, the number of parts is large and the cost is high. An object of the present invention is to eliminate the above-mentioned drawbacks, to provide a semiconductor device which has good heat dissipation, is easy to assemble, and has a small number of parts.

[0005]

In order to achieve the above object, the semiconductor device of the present invention has one electrode of three or more semiconductor elements each having electrodes on both sides on a common conductive substrate. One end of each lead terminal is fixed to the other electrode of each semiconductor element, and the other end of each lead terminal and at least a part of one surface of the conductive substrate are exposed to expose each semiconductor element. Is coated with a resin. Then, a mounting hole is formed in the exposed portion of the one surface of the conductive substrate, one electrode of each semiconductor element is fixed on the other surface of the conductive substrate, The terminals are integrally connected until the resin coating step, and it is effective that the terminals are made of strip conductors separated after the resin coating step.

[0006]

Since at least three semiconductor elements are fixed to a common conductive substrate, the heat generated in each element can be brought into contact with the exposed surface of the substrate through the substrate or to the exposed surface. The heat can be radiated to the cooling body, which enables uniform cooling. Then, by assembling each semiconductor element on one surface of the substrate, the assembly is simplified, and the characteristics of each element can be easily measured by using the exposed portions of the substrate and the lead terminals. Also, since no connecting piece is required, the number of parts can be reduced.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention, which is a component used in FIGS. That is, the bottom electrodes of the silicon surge absorber chips 1, 2 and 3 are fixed on the copper substrate 5 shown in FIG. 4 with solder as shown in FIG. 1, and the top electrodes of the chips are shown in FIG. The heads of the strip-shaped lead portions 11, 12, 13 of the lead frame 10 are soldered. Then, the resin 4 is molded to cover the chips 1, 2, and 3. At this time, since the chip exists on the front surface of the substrate 5, the back surface 51 of the substrate can be entirely exposed. After that, the connecting portion 14 of the lead frame 10 which is exposed to the outside of the resin 4 is cut off to obtain the state shown in FIG. Since the lead parts 11, 12, and 13 are flat plates, they can be freely bent and connected to the outside. In this state, the characteristics of each chip can be checked by using one of the lead portions 11, 12, 13 and the exposed substrate surface 51.

FIG. 6 is a view of another embodiment viewed from the back surface side of the substrate. In this case, only the back surface of the substrate 5 is exposed and the front surface side is entirely covered with the resin 4 to enhance protection for the chip. There is. FIG. 7 shows a state in which this semiconductor device is mounted on the cooling body 6, and the through holes 7 formed in the substrate 5 and the resin 4 are used to fix the semiconductor device with mounting screws 8.
In the embodiment shown in FIG. 1 as well, if the back surface of the substrate 5 is brought into close contact with the cooling body using the through holes 7 formed in the board 5 as well, from the chips 1, 2, 3 to the back surface 51 of the substrate 5. Since the thermal resistance of 1 is 1/10 of the thermal resistance from the chip of the conventional semiconductor device of FIG. 2 to the surface of the resin 4, very good heat dissipation can be performed. As mentioned above, the embodiments with three chips have been described.
It goes without saying that the same operation can be performed in the case of four or more.

[0009]

According to the present invention, one electrode of a plurality of semiconductor elements is connected to each other by a conductive substrate, and one surface of the substrate is exposed to improve heat conduction to a cooling body. Thus, a highly reliable semiconductor device can be obtained.
Also, by connecting the other electrode to the lead part of the lead frame, the number of parts other than the chip can be reduced from the conventional 6 to 2
The number of parts has been reduced, the cost has been reduced, the assembly has been simplified, and the number of assembly steps has been reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of a silicon surge absorber semiconductor device according to an embodiment of the present invention.

FIG. 2 is a perspective view of a conventional silicon surge absorber semiconductor device.

FIG. 3 is an equivalent circuit diagram of the semiconductor device shown in FIGS. 1 and 2.

4 is a perspective view of a substrate of a component used in the semiconductor device of FIG.

5 is a perspective view of a lead frame of a component used in the semiconductor device of FIG.

FIG. 6 is a perspective view of a silicon surge absorber semiconductor device according to another embodiment of the present invention.

7 is a cross-sectional view showing how the semiconductor device of FIG. 6 is attached to a cooling body.

[Explanation of symbols]

 1 Silicon Surge Absorber Chip 2 Silicon Surge Absorber Chip 3 Silicon Surge Absorber Chip 4 Resin 5 Copper Substrate 6 Cooling Body 7 Through Hole 10 Lead Frame 11 Lead Part 12 Lead Part 13 Lead Part

Claims (4)

[Claims] 1. One of electrodes of three or more semiconductor elements each having electrodes on both sides is fixed on a common conductive substrate,
One end of each lead terminal is coupled to the other electrode of each semiconductor element, and the other end of each lead terminal and at least a part of one surface of the conductive substrate are exposed, and each semiconductor element is made of resin. A semiconductor device characterized by being covered. 2. The semiconductor device according to claim 1, wherein a mounting hole is formed in an exposed portion of one surface of the conductive substrate. 3. The semiconductor device according to claim 1, wherein one electrode of each semiconductor element is fixed on the other surface of the conductive substrate. 4. The semiconductor device according to claim 1, 2 or 3, wherein each lead terminal is integrally connected until the resin coating step and is made of a strip-shaped conductor which is cut off after the resin coating step is completed.