JPS5852689Y2 - Metal support for semiconductor devices - Google Patents

Description

[Detailed Description of the Invention] The present invention is directed to the electrode structure of a semiconductor device, especially the transfer
The present invention relates to a metal electrode support for a semiconductor device that is mold-sealed.

Transfer molding is often used for semiconductor devices, such as transistors and diodes, due to the efficiency of molding and low cost, and this method has also come to be used in high-power semiconductor devices. Ta.

Conventionally, for example, as a metal support for a power semiconductor device, a structure that has good heat dissipation and is easy to manufacture has been developed.
It is proposed in No. 43723.

The support shown here has an element fixing part thicker than the other external leads, and integrates an appropriate number of other external leads with connecting strips, and is made by punching a conductive metal material. It is something that

The present invention aims to eliminate the stress applied to semiconductor elements during the mounting of semiconductor devices, and to improve efficiency during manufacturing.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1.2 shows a semiconductor device assembled and sealed with a conductive metal support formed from a conductive metal body, which will be described later.
1 is this metal support, and 2 is an element fixing part to which a semiconductor element 3 such as a transistor or diode is fixed.This part is thicker than other lead parts and has good heat dissipation. .

Reference numeral 4 denotes an external lead extending from the fixed portion 2, and is, for example, a collector lead of a transistor.

5 and 6 are external leads arranged close to and parallel to the external lead 4, and have the same thickness as the external lead 4, and connect the semiconductor element 2 and the thin metal wire 7.
, 8, and constitute, for example, the base and emitter leads of a transistor.

These outer leads 5 and 6 are integrally formed with the fixing portion 2 and the outer lead 4 by stamping as described below.

Reference numeral 9 denotes a semiconductor element 3 which is transfer-molded with epoxy resin or the like for sealing around the semiconductor element 3.

10 is a mounting hole for screwing the metal support 1 to a chassis or the like.

Next, the preparation of the electrode support 1 and the assembly of the semiconductor device shown in FIGS. 1-2 will be explained.

FIG. 3 shows the state in which the electrode support 1 is formed, and shows one punching pattern.

In FIG. 3, reference numeral 11 denotes a strip-shaped conductive metal body for punching and forming a large number of electrode supports 1, and is made of a material such as steel that has good thermal and electrical conductivity and is rich in ductility. A plurality of element fixing portions, mounting holes, and one end portion of the external lead are formed on one side and the other side with respect to the center line O in the direction.

Components in FIG. 4 that correspond to those in FIG. 1 are given similar numbers.

That is, an element fixing portion 2 and a mounting hole 1 are provided on one outer side of the strip-shaped conductive metal body 11 with respect to the center line O in the longitudinal direction.
0. Part 4 a of the lead part 4 extending from the fixed part 2
, 4a, one end portions 5a, 5a of the lead portions are formed by press punching.

Further, on the other outer side with respect to the center line O, an element fixing part 2' having a shape symmetrical to the one outer side, a mounting hole 10', a part 4a of the lead part, and one end parts 5a and 6a are formed. ing.

As is clear from Fig. 3, a large number of these objects are formed in a row, and the area near the center line O is simply a flat plate. A metal support 2 as shown in FIG. 1 is formed.

In other words, the flat plate-shaped portion includes one end of the lead wire 4.4' connected to 4a, 4a', 5a, 5a', 6
a, 6 Lead parts connected to a'5゜5',6.6'
is formed by stamping after the fixation of the semiconductor element and the transfer molding process.

In this flat plate-shaped portion, 20 portions (hatched portions) shown in FIG. 3 are punched out and removed, and the metal supports shown in FIG. 1 are formed on both sides of the center line O, respectively.

Furthermore, what should be noted in the structure of FIG. 3 is that the node parts 4 and 5 combined with the element fixing part 2
．． 6 and parts thereof 4 a , 5 a , 6 a and the lead part 4 combined with this on the element fixing part 2' side
', 5', 6' and part thereof 4 a', 5 a'
, 6a' are arranged alternately in the central portion, that is, the flat plate-like portion.

In other words, the lead parts are 5', 5.4', 4.6' from the left.
. They are arranged at equal intervals in the order of 6, and the element fixing parts 2 and 2
' is arranged slightly offset with respect to the vertical direction of the center line O.

By alternately arranging the lead portions of the supports on both sides of the center line when creating the electrode support, the efficiency of material removal from the conductive metal body 11 is extremely high, and the conductive metal body 11 The width can also be made smaller, which greatly contributes to more efficient use of materials and cost reduction.

This structure is particularly effective for large-sized semiconductor devices in which the lead portions can be spaced widely.

Note that FIG. 4 is a structural cross-sectional view taken along the line IV-IV" in FIG. 3.

As is clear from FIG. 4, the central portion corresponding to the lead portion is thin, the element fixing portions 2 and 2' constitute thick-walled portions, and the portions forming mounting holes 10 and 10' at both ends are medium-thick. It is a thick part.

Next, a method for assembling the semiconductor device shown in FIG. 1 will be explained.

First, a conductive metal body 11 as shown in FIG. 3 is punched out and then plated to fix the semiconductor element 3 to the element fixing portions 2, 2'.

Then, the ends 5a, 5a', 5 of the element and the lead part
a.

Connect a thin metal wire to 6a' and transfer using resin.
Apply the mold.

After that, unnecessary parts 20 of the flat plate-shaped part are punched out, and the lead parts 4, 5.6 are further plated with solder, and the connecting parts 21 and 21' shown in Fig. 3 are cut and separated to complete the semiconductor device shown in Fig. 1. do.

FIG. 5 shows an element for making an electrode support according to another embodiment of the present invention.

That is, the lead portions 4.4' and 5.5' in FIG.
, 6.6' are connected at a connecting portion 30.

FIG. 6 shows a state in which the semiconductor device shown in FIGS. 1 and 2 described above is attached to a chassis or the like.

That is, FIG. 6 shows the case fixed to the chassis 40 through the mounting hole 10 with screws 50.

At this time, according to the present invention, even if the forming part of the mounting hole 10 is slightly distorted by the tightening force of the screw 50 etc., the tightening stress will not be transmitted to the element fixing part 2 because the element fixing part 2 is formed thick. Therefore, the element will not break or peel off.

Furthermore, since the element fixing part is formed to be the thickest, even if the element instantaneously generates a large amount of heat, the heat capacity of the element fixing part is large, and thermal destruction of the element can be prevented.

In addition, since the lead part is arranged in the center of the strip-shaped conductive metal body 11, when forming the conductive metal body 11 by rolling, the central part corresponding to the lead part that needs to be rolled thinnest is placed at one place. Electrode supports for a pair of semiconductor devices can be created simply by rolling.

Moreover, since the lead parts are arranged alternately in the center of the conductive metal body, the width of the metal material can be reduced, and rolling is particularly easy because the width of the center part where the thickness is to be reduced is small. becomes.

As described above, the electrode support for a semiconductor device according to the present invention is easy to manufacture, allows efficient use of materials, and has great practical effects in improving the reliability of the semiconductor device.

[Brief explanation of drawings]

FIG. 1 is a plan view of a semiconductor device assembled using a support according to the present invention, FIG. 2 is a sectional view taken along line III' in FIG. FIG. 4 is a cross-sectional view taken along the line IV-IV' in FIG. 3;
FIG. 5 is a plan view of a metal body in the same embodiment, and FIG. 6 is a sectional view of the device shown in FIG. 1 attached to a chassis. 1.1'... Electrode support, 2.2'...
・Element fixing part, 4.4'. 5.5', 6.6'... Lead part, 10, 10
'...Mounting hole, O...Center line.

Claims (1)

[Scope of utility model registration request] It has a semiconductor element fixing part, a mounting hole forming part, and a lead part formed by punching out a strip-shaped conductive metal body, and the mounting hole forming part and the lead part extend from one side and the other of the fixed part, respectively. The thickness of the fixing part is larger than the thickness of the mounting hole forming part and the lead part, and the first element fixing part is arranged on one side with respect to the center line in the longitudinal direction of the metal body. A second element fixing portion is formed on the other side, and the first,
A metal support for a semiconductor device, characterized in that lead parts extending from the second fixing part are arranged alternately in the center of the metal body.