JPS60254643A - Resin-sealed semiconductor device - Google Patents

Abstract

PURPOSE:To improve the reliability by preventing the leakage of filler by a method wherein the peripheral surface inside the case located above the gelled filler in the lower part inside the case and slightly above the peripheral surface with which the sealing resin come in contact and the surface of the gelled filler is provided with shelf-like projections. CONSTITUTION:A metallic heat-dissipating plate 3 is fitted in the bottom: the lower space is filled with the gelled filler 8, whereas the space above the filler 8 is filled with the sealing resin 9. A streak or more of steps 10a extending in the circumferential direction are formed in the upper inner peripharal surface of the case 10. Besides, the shelf-like projections 10b extending in the circumferential direction are formed in the inner peripheral surface of the case 10 slightly above the surface S of the filler 8. The steps 10a are provided at positions, etc. opposed to the outer peripheral surface of a lead supporter 7, and the creep-up of the gelled filler 8 is prevented by increasing the creep distance of the inner surface of the case 10.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a resin-sealed semiconductor device, and in particular, a resin-sealed semiconductor device that is less likely to leak a filler from inside an envelope and has higher reliability than conventional similar devices. The present invention relates to a resin-sealed semiconductor device that can be manufactured with high yield.

[Technical Background of the Invention] FIGS. 3 and 4 show the structure of a conventionally known resin-sealed power semiconductor device.

In the figure, reference numeral 1 denotes a bottomless box-shaped case consisting only of side walls made of resin, and a heat sink plate 2 made of metal is fitted to the bottom of the case 1. An insulating substrate 3 is bonded onto the heat sink 2 via a solder layer 4, and the lower end portions 5a of the leads 5
solder B6 to the element mounting base formed on the insulating substrate 3.
It is glued through. A lead support member 7 made of resin that holds the intermediate portion of the lead 5 is inserted into the case 1 at the L-most position, and the lead support member 7 constitutes a lid for the case 1. In the lower space inside case 1,
A gel-like filler 8 made of a gel-like silicone resin or the like is filled, and a curable sealing resin 9 made of an epoxy resin or the like is filled in the case interior space on either side of the gel-like filler 8.
The sealing resin 9 is also filled in the gap g between the outer peripheral surface of the lead support member 7 and the inner peripheral surface of the booth 1.

When manufacturing a semiconductor device having the above structure, first, the lower end portions 5a of the leads are fixed to the element mounting base on the insulating substrate 3 inside the case 1 via the solder layer 6, and then the lead support member 7 is attached to the case. Position it at the top position within 1. Next, the resin injection notch 7a provided in the lead support member 7
After injecting the gel-like filler 8 into the case 1 through the gap (see FIG. 1), the semiconductor device is manufactured by injecting the sealing resin 9 and further curing the sealing resin 9. ing.

[Problems in the Background Art] In the resin-sealed semiconductor device as described above, the physical properties of the silicone gel used as the gel filler and the epoxy resin used as the sealing resin, and the characteristics of the semiconductor device There were the following problems with the manufacturing method.

■ If there is poor adhesion between the inner circumferential surface of case 1 and the sealing resin, minute voids are likely to occur along the inner circumferential surface of case 1.
Therefore, an accident in which the gel-like filler 8 leaks out of the case 1 through the gap is likely to occur.

In particular, silicone gel used as a gel-like filler has a large coefficient of thermal expansion, so when the semiconductor device is subjected to a temperature cycle test (-40°C to +120°C), the inner peripheral surface of case 1 The silicone gel sometimes spewed out of the case 1 through the gaps formed along the sides.

■ Conventionally, the amount of gel-like filling injected into case 1 was set at a predetermined level (
(a) In the above cases, voids as in (i) are likely to occur, and as a result, the above-mentioned accident of leakage of the gel-like filling is likely to occur.

Therefore, conventional resin-sealed semiconductor devices have low reliability.
Also, the yield was relatively low.

[Object of the Invention] An object of the present invention is to provide a highly reliable resin-sealed semiconductor device that is less likely to cause leakage of gel-like filling.

[Summary of the Invention] The resin-sealed semiconductor device improved by the present invention has at least one stepped portion extending on the inner circumferential surface of the case in contact with the sealing resin, and a gel-like filling. A feature is that a shelf-like protrusion extending along the inner peripheral surface of the case is formed slightly above the surface of the object. Providing the stepped portion on the inner peripheral surface of the case improves the adhesion between the sealing resin and the case, while providing the protrusion on the inner peripheral surface of the case prevents the gel-like filling from creeping up. can do. In addition, by providing the protrusion, it is possible to visually confirm the injection liquid level of the gel-like filling into the case,
As a result, overfilling of the gel filler can be prevented.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIG. Note that in FIG. 1, parts indicated by the same reference numerals as in FIGS. 3 and 4 indicate the same parts as in the conventional semiconductor device.

In the semiconductor device of the present invention shown in FIG.
The special feature of case 0 is that it has a structure different from that of conventional case 1. That is, in the semiconductor device of the present invention, at least one or more step portions 10a (or protrusions) extending in the circumferential direction are formed on the upper inner circumferential surface of the case 10, and at least one step portion 10a (or protrusion) is formed on the upper inner peripheral surface of the case 10. It is characterized in that a shelf-shaped protrusion 10b that similarly extends in the circumferential direction is formed at an upper position. The stepped portion 10a is most preferably provided at a position facing the outer peripheral surface of the lead support member 7 as shown, but it may be located at a position lower than this as long as it contacts the sealing resin 9. The stepped portion 10a increases the bonding force between the sealing resin 9 and the case 10, and at the same time increases the creepage distance in the vertical direction along the inner surface of the case 10.
This is effective in preventing the gel-like filling from creeping up along the inside of the case 10.

On the other hand, the protrusion 10b is a part provided to prevent the gel-like filling 8 from creeping up, and the formation of the protrusion 10b allows the gel-like filler 8 to move along the inner surface of the case. Climbing is prevented. It is desirable that the protrusion 10b be formed at a position slightly above the final filling liquid level S of the gel-like filling 8.

The cross-sectional shape of the stepped portion 10a and the protrusion 10b may be a square cross-section, a rectangular cross-section, or a trapezoidal cross-section as shown in FIG. 1, but as shown in FIG. When formed in a cross-sectional shape with a thick tip, the stepped portion 1
The bonding force between Oa and the sealing resin 9 is further increased, and at the same time, the effect of preventing the gel-like filler from creeping up is further improved.

[Effects of the Invention] The resin-sealed semiconductor device of the present invention as shown in FIG. 1 and the conventional semiconductor device having the structure as shown in FIG. 4 were manufactured in equal numbers, and both were subjected to a temperature cycle under the same conditions. Furthermore, the adhesion between the case and the sealing resin and the workability during manufacturing were investigated for both cases.

As a result, the semiconductor device of the present invention has a 50 times longer failure time in a temperature cycle test than a conventional semiconductor device, and in terms of adhesion or sealing, half of the conventional devices have defects. It showed a 100% pass rate, and in terms of workability, it was found that the work time could be reduced by 30% compared to conventional products because the injection liquid of the gel-like filler 8 could be checked against the protrusion 10b as a reference.

As described above, according to the present invention, a highly reliable resin-sealed semiconductor device is provided in which there is little fear that the filler will leak from inside the envelope. The resin-sealed semiconductor device improved by the present invention not only has higher reliability than conventional products, but also has better workability and can be manufactured with higher efficiency and yield than conventional products. It can be manufactured at a lower cost than other products.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of essential parts of an embodiment of a resin-sealed semiconductor device of the present invention, FIG. 2 is a cross-sectional view of a modified embodiment of the present invention, and FIG.
The figure is a plan view of a conventional resin-sealed semiconductor device, and FIG. 4 is a sectional view taken along the line IV-rV in FIG. 3. 1.10... Case, 2... Heat sink, 3...
Insulating substrate, 4.6... Solder layer, 7... Lead support member, 5... Lead, 8... Gel-like filling,
9... Sealing resin. Patent applicant Toshiba Corporation Agent Patent attorney 1) Eiji Figure 1 Figure 20 Figure 4 Procedural amendment (method) September 1980 IQ Commissioner of the Patent Office Manabu Shiga 1, Indication of case 1981 Patent Application No. 109691 2
, Title of the invention Resin-encapsulated semiconductor device 3, Relationship with the case of the person making the amendment Patent applicant 72 Horiyo-cho, Saiwai-ku, Yosaki City, Kanagawa Prefecture (Shipping date: August 28, 1980) 6. Amendment Target application and specification

Claims (1)

[Claims] 1. A bottomless box-shaped case made of resin consisting only of side walls, a heat sink fixed to close the bottom of the case, and a lid-shaped lead inserted into the top position of the case. The lower space inside the case is filled with a gel-like filling, and the space inside the case on the -L side from the gel-like filling is filled with a sealing resin. In a resin-sealed semiconductor device filled with resin, at least one or more step portions extending in the circumferential direction are formed on the inner peripheral surface portion of the case that contacts the sealing resin; 1. A resin-sealed semiconductor device characterized in that a shelf-shaped protrusion is formed slightly above the surface position of the gel-like filler and protrudes along the inner peripheral surface of the case.