JPS6344298B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor device comprising a power transistor block, and more specifically to a power transistor block having a heat sink assembly structure which has many manufacturing advantages.

Problems in manufacturing molded power transistors and series-parallel power transistor modules include making bonding work and characteristic checks as easy as possible during each assembly process, and the structure of external terminals being simple and easy to connect. It is also desired that transistors, series and parallel transistor modules be compatible with each other.

SUMMARY OF THE INVENTION An object of the present invention is to provide a power transistor block with a heat sink assembly structure that skillfully solves the above-mentioned problems.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a sketch of the heat sink assembly of this embodiment, and FIG. 2 shows a plan view of a power transistor block on which a semiconductor is mounted.

A strip along one side of the rectangular copper-based metal heat sink 1,
A wire bonding pad 3 made of iron-nickel metal is placed through an insulating plate 2 made of Al ₂ O ₃ with metallization on both sides, and a copper U-shaped terminal 4 for external terminal connection is provided at one end of the pad. The heat sink 1
Similarly, an insulating plate 2 is placed along one opposite side of the
A wire bonding pad 31 is disposed through the wire bonding pad 1, and a U-shaped terminal 41 is provided at one end of the wire bonding pad 31. Furthermore, a molybdenum-based temperature compensating plate 11 is provided in the center of the heat sink 1, and a U-shaped terminal 42 is provided in a part of the periphery. It is preferable to apply Ni-plating to these parts in advance, and assemble them into a heat sink assembly with terminals by silver soldering.

Next, as shown in FIG. 2, the transistor chip 5 is mounted by soldering on the molybdenum plate which is the temperature compensation plate 11 on the heat sink assembly, and the bonding pads 3 and 31 are mounted using aluminum wires 6 and 61.
Wire bonding is done approximately in the center of the In addition, a diode 51 is mounted on the heat sink 1 by solder, if necessary, and wire bonded to approximately the center of the bonding pad 31 using an aluminum wire 62. The U-shaped terminals 4, 41, 42 of the power transistor block thus formed are B, 41, and 42, respectively.
These become E and C terminals.

In this way, the connection terminals or terminal areas are arranged on a substantially rectangular heat sink, at one end of a band-shaped pad arranged along the side of the heat sink, or at a part of the periphery of the heat sink. Therefore, the bonding area is wide and the bonding work is extremely easy. Furthermore, it will be easier if the length of the U-shaped terminal is made shorter.

Next, as shown in the plan view of the molded power transistor in FIG. 3, the power transistor block 7 is placed on the copper plate 71 via an insulating plate (not shown), and as shown in the terminal development diagram in FIG. The plate-shaped external terminals B, C, and E are arranged as shown in the terminal layout diagram in Figure 4, and the U-shaped terminals B, C for connection of the block are encapsulated to protect the bonding wires using silicone RTV in Figure 3. , E. Next, a silicone RTV and an epoxy potting resin are injected into the FR-PET (Teijin Ltd. product name) case 72, and the resin is sealed leaving a part of the external terminals to form a molded power transistor. do.

In that case, characteristics should be checked at each manufacturing process, such as after bonding the transistor block, after RTV encapsuling of the block, before connecting the external terminals of the assembly, and before sealing the assembly with resin. However, this can be easily done using a U-shaped terminal for the same reason as mentioned above that the bonding work is easy. As a result, it is possible to assemble with less loss while eliminating defective products.

Next, as shown in the plan view of the power transistor module in FIG. 6, two power transistor blocks 81 and 82 are placed on a copper plate 83 with an insulating plate (not shown) interposed therebetween, and as shown in FIG. Fold the plate-shaped external terminals C ₁ , B ₁ B ₂ , E ₁ E ₂ shown in the terminal development diagram at the chain lines and arrange them as shown in the terminal forming diagrams in Figures 7 and 8 (side view). By soldering the connection terminals C ₁ , B ₁ , B ₂ , E ₁ , and E ₂ of the block shown in FIG. 6, a parallel module circuit can be formed. In this case, C ₂ and C ₁ are connected by an appropriate means.

In addition, for series connection, use the plate-shaped external terminals C ₁ , B ₁ , C ₂ E ₁ , B ₂ , E ₂ shown in the terminal development diagram in FIG.
Bend the terminals at chain lines 1, 2, 3, or 3' and place them as shown in the terminal forming diagrams in Figures 10 and 11 (side view). By soldering the connection terminals, a series module circuit can be formed.

The blocks shown in FIG. 6, which are connected in series or in parallel, are similar to molded power transistors.
A series or parallel power transistor module is made by leaving a part of the external terminal and sealing it with resin.

In this way, the connection terminals or terminal areas of the power transistor blocks are located around the heat sink and are arranged in a straight line when multiple blocks are lined up, so the external terminals can be pressed against the board. It can be made inexpensively by molding, and connections can be easily made by soldering. The external terminals for series-connected modules, which originally have a low material utilization rate, have a U-shaped terminal arranged in a straight line, so the material utilization rate is approximately
This was an improvement of 30%, and the number of bending steps could be reduced.

In addition, this power transistor block can be used for molded transistors and series-parallel power transistor modules, and has commonality and compatibility.
Therefore, there is an advantage that mutual flexibility is possible before resin sealing.

Incidentally, it may be more advantageous to provide a U-shaped terminal in a block and connect an external terminal to the area as a connection terminal area than to arrange the U-shaped terminal in the block and connect the external terminal to the block.

As explained above, according to the semiconductor device equipped with the power transistor block according to the present invention, the connection terminals or the connection area are arranged around the metal heat sink, so workability such as bonding work is improved. . In addition, measurements can be easily made using the connection terminals or connection areas placed around the metal heat sink, making it easy to check characteristics and reduce the product defect rate.This effect is particularly effective for resin-sealed molded power transistors. noticeable. Furthermore, since the connection terminals or connection areas of any two of the emitter, collector, and base are arranged on a straight line parallel to one side of the heat sink, external terminals formed from metal plates can be formed at low cost. This is particularly effective in the case of a series-parallel power transistor module in which a plurality of transistor blocks are arranged. Furthermore, since semiconductor devices consisting of a plurality of transistors are assembled using transistor blocks having the same structure and connection terminals or connection areas arranged at the same position, the commonality and compatibility of semiconductor device members is extremely high.

As described above, the semiconductor device of the present invention achieves the effect that many problems are solved in one.

[Brief explanation of the drawing]

FIG. 1 is a sketch of a heat sink assembly according to an embodiment of the present invention, FIG. 2 is a plan view of a power transistor block, FIGS. 3, 4, and 5 are internal plan views of a molded power transistor, respectively. External terminal arrangement diagram, external terminal development diagram, Figure 6 is an internal plan view of a series or parallel power transistor module, Figures 7, 8, and 9 are external terminal molding diagrams of external terminals for parallel connection, respectively. FIGS. 10, 11, and 12 are a side view, a developed view of an external terminal, and a developed view of an external terminal for series connection, respectively. 1...Metal heat sink, 11...Temperature compensation plate, 2,
21... Insulating plate, 3, 31... Wire bonding pad, 4, 41, 42... Connection terminal, 5
...Semiconductor, 7,81,82...Power transistor block, 71,83...Copper plate, 72,84
……Case.

Claims (1)

[Scope of Claims] 1. A substantially rectangular metal heat sink, and band-shaped emitters and base wire bonding pads disposed on the metal heat sink along one side and the other side, respectively, with an insulating plate interposed therebetween. , a connection terminal or connection area of the emitter provided at one end of each of the wire bonding pads, a connection terminal or connection area of the base, a semiconductor element mounted approximately at the center of the heat sink, and a periphery of the heat sink. It consists of a collector connection terminal or connection area provided in a part of the collector and an external terminal formed from a metal plate, and the connection terminal or connection area connected to any two of the emitter, collector, and base. A semiconductor device comprising one or more power transistor blocks arranged on a straight line parallel to one side of a heat sink. 2. The metal heat sink of the power transistor block is disposed on a steel plate via a second insulating plate, and the power transistor block except for a part of the external terminals is sealed with resin. The semiconductor device according to item 1. 3 A plurality of power transistor blocks are arranged so that their collector connection terminals or connection areas and emitter connection terminals or connection areas are located on a straight line, and their base connection terminals or connection areas are separate. 3. The semiconductor device according to claim 2, wherein the semiconductor device is arranged so as to be located on a straight line, and is connected in series or in parallel by external terminals.