JPH02246359A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the deterioration of the performance and shortening of the lifetime of a semiconductor chip due to heating at the time of mounting by increasing the bonding power of a stage, on which the semiconductor chip is loaded, and a resin sheathing sealing the chip and stage. CONSTITUTION:Through-holes 13 are filled with one parts of a resin sheathing 4 and one parts of the resin sheathing are formed, and the expansion of the resin sheathing 4 peeling the resin sheathing 4 and a stage 12 is inhibited by engaging force with a resin filled into the through-hole 13 and the through-hole 13. That is, the stage 12 and the resin sheathing 4 are bonded by the adhesion of a surface and a surface and engaging force stronger than the adhesion of the engaging of one parts of the sheathing resin 4 with the through-holes 13. Consequently, even when moisture intruding into the resin sheathing 4 intends to expand, the deformation of sheathing is inhibited by bonding power utilizing engaging force. Accordingly, no crack is generated, the reliability of a device is improved and the service life thereof can be lengthened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a resin-sealed semiconductor device, and particularly to a novel configuration for eliminating cranks that occur in the sealing resin due to heating during mounting.

3. Detailed Description of the Invention [Prior Art] FIG. 7 is a schematic sectional view showing a conventional semiconductor device sealed with resin, and FIG. 8 is a schematic sectional view showing thermal expansion of the resin exterior of the semiconductor device. be.

In FIG. 7, a semiconductor device 1 has a semiconductor chip 2 mounted on a metal stage 3, and pads (not shown) of the semiconductor chip 2 and lead terminals 5 are connected with thin metal wires 10. The lead portions of a plurality of lead terminals 5 are led out from the side end surface of the resin sheath 4 that seals the thin metal wire 10, etc. of the metal stage 3.

Such a semiconductor device 1 is mounted by soldering the lead terminals 5 to an external circuit, and when the lead terminals 5 are heated to, for example, about 230° C. for this mounting, the resin sheath 4 is also heated. Then, the moisture that has entered the resin sheath 4 along the lead-out portion of the lead terminal 5 and through the resin sheath 4 expands, and as shown in FIG. 8, the lower part of the resin sheath 4 peels off from the stage 3 and swells. Cracks 6 were sometimes generated from the ends of the stage 3.

In this way, the rack 6 impairs the airtightness of the exterior casing 4, reduces the reliability of the semiconductor device 1, and shortens its life.

FIG. 9 is a cross-sectional view (A) and a plan view (B) of a stage according to another conventional example, in which the stage 7 has a plurality of recesses (dimples) 8 formed on the lower surface to enlarge the area of contact with the resin exterior. This is what I did.

[Problem to be solved by the invention]

A semiconductor device in which the area of contact with the resin sheath 4 is increased by the recess 8, thereby increasing the adhesion between the stage 7 and the resin sheath 4, has the effect of suppressing the occurrence of cracks 6 to some extent, but it is incomplete. However, other countermeasures were strongly desired.

An object of the present invention is to improve the reliability of a semiconductor device and extend its life by configuring a semiconductor device so that the cracks do not occur.

[Means to solve the problem]

According to FIG. 1 and FIG. 6 showing an embodiment of the semiconductor device according to the present invention, a metal plate stage 12 for mounting a semiconductor chip is provided with a plurality of through holes 13 that are opened larger on the upper surface than on the lower surface. and a semiconductor chip 2 mounted on the upper surface thereof is sealed with a resin sheath 4, or a metal plate stage for mounting a semiconductor chip] 6 has an opening on the upper surface than the opening on the lower surface of the stage 16.
Stage 1
6 and a semiconductor chip mounted on its upper surface are sealed with resin.

[Effect]

According to the above means, a part of the resin exterior is formed by filling the through hole, and the expansion of the resin exterior that causes the resin exterior and the stage to be peeled off is caused by the engagement force between the through hole and the resin filled in the through hole. becomes inhibited. That is, in the prior art, the expansion and deformation of the resin exterior was suppressed by the adhesive force between surfaces, but the stage and resin exterior according to the present invention have a structure that suppresses the expansion and deformation of the resin exterior by the adhesive force between the surfaces and the through hole. A part of the two is engaged, and the two are bonded by an engagement force that is stronger than the adhesion force.

Therefore, even if moisture that has entered the resin exterior tries to expand, the deformation of the exterior is suppressed by the bonding force using the engagement force, and cracks do not occur in the resin exterior.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A semiconductor device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic sectional view showing a semiconductor device according to an embodiment of the present invention, and FIG. 2 is a plan view of the stage shown in FIG. 1.

In FIG. 1, in which the same reference numerals are used for parts common to those in the previous figure, a semiconductor device 11 has a semiconductor chip 2 mounted on the upper surface of a stage 12, and pads (not shown) of the semiconductor chip 2 and lead terminals 5 are connected with metal. Connected with thin wire 10, semiconductor chip 2
．． Stage 12. Resin exterior 4 for sealing thin metal wire 10 etc.
A plurality of lead terminals 5 are led out from the side end surface.

The semiconductor chip 2 is mounted on the upper surface of the stage 12 by thermocompression bonding or the like with an adhesive layer 9 adhered to the lower surface of the semiconductor chip 2.
A portion 4a of the resin sheath 4 is formed by filling a through hole 13 formed in the stage 12.

In FIGS. 1 and 2, a stage 12 made of iron-nickel alloy or the like is provided with a plurality of through holes 13 (25 in the figure), and a sealing resin is applied from the bottom surface of the stage 12. The cross-sectional shape of each through hole 13 to be injected is tapered or stepped, with the upper surface opening larger than the lower surface.

FIGS. 3(A) and 3(D) are enlarged sectional views showing an embodiment of a through hole formed in a stage according to the present invention.

In FIG. 3(a), the tapered through hole 13a is formed by etching by forming etching masks 14 and 15 on the stage 12 as shown by the dashed line in the figure.

In FIG. 3(U), the stepped through hole 13b consisting of the small diameter part 13c and the large diameter part 13d is formed by punching a hole with the same diameter as the small diameter part 13c in the stage 12 by punching, and then by pressing. The large diameter portion 13d is placed on the stage 12.
The stage 12 is formed on the upper surface, and then flattened by flat pressing to crush the bulge caused by the formation of the large diameter portion 13d.
The top surface is flat.

After mounting the semiconductor chip 2 on the stage 12,
The bonding force between the stage 12 and the resin sheath 4 formed by filling the through hole 13 with the portion 4a is determined by the adhesion force between the lower surface of the stage 12 and the resin sheath 4 that is in close contact with the lower surface, and the adhesion force between the resin sheath 4 and the stage 12, which are formed by filling the through hole 13 with the portion 4a. This is the resultant force with the engagement force of the part 4a of the formed resin sheath 4, and while the adhesion force is about 12g/+u+'', it has been confirmed through experiments that the engagement force is much stronger than the adhesion force. It was done.

Table 1 below shows the bonding strength between the stage 12 according to the present invention and the resin body formed on its lower surface, and Table 1 shows the bonding force between the stage 12 according to the present invention and the resin body formed on its lower surface. The bonding force (adhesion force) was actually measured using a sample as shown in FIG. 4. This is an example of actual measurement.

FIG. 4 is a side view of the sample used for the bond strength measurement in Table 1.

In FIG. 4, the sample is made by molding a resin body 21 on the lower surface of the stage 12 or 7, and adhering a shank 20 for tensile testing to the upper surface of the stage 12 or 7 and the lower surface of the resin body 21. However, the stage 12 according to the present invention is made of a 51 square iron-nickel alloy plate with a thickness of 0.3 am, and a lower opening diameter of 0.35 mm by etching.
, 61 tapered through holes 13 with an opening diameter of 0.55 mm on the top surface are drilled, and the conventional stage 7 has a diameter of 5 mm.
- 61 recesses 8 are formed in a square iron-nickel alloy plate.

As is clear from Table 1, the bonding force between the stage 12 and the resin body 21 according to the present invention is higher than that of the conventional stage 7 and the resin body 2.
It exhibits a bond strength approximately 80 times stronger than that of 1.

This difference in bonding force is caused by the fact that in the conventional stage 7 and resin body 21 that utilize only adhesion force, it is easy to separate at the joint surface, whereas the through hole 13 is partially filled with the resin body 21. The stage 12 and the resin body 21 of the present invention are separated because the filled portion of the resin body 21 needs to be torn off.

FIGS. 5(<) and 5(0) are cross-sectional views showing the main parts of the sample for bonding force measurement after the bonding force measurement using the stage according to the present invention.

The fifth figure shows the main parts of the separated stage 12 and resin body 21.
In the figure, a resin body 21 separated from the stage 12
is broken at the lower opening of the through hole 13, and a portion 21a of the resin body 21 remains in the through hole 13 of the stage 12 from which the resin body 21 has been separated.

Table 2 The above Table 2 shows that the semiconductor device 11 according to the present invention and the semiconductor device 1 according to the prior art were exposed to moisture in a high temperature atmosphere of 85° C. and humidity of 85%, and then in a high temperature atmosphere of 200° C. This is experimental data for examining the presence or absence of cranks that occur in the resin sheath 4 when it is dried for about 60 seconds.

As is clear from Table 2, in the semiconductor device 11, no crank occurs in the resin sheath 4.

FIG. 6 is a plan view (A) of a stage of a semiconductor device according to another embodiment of the present invention and an enlarged sectional view (U) of a portion thereof.

In FIG. 6(A), the metal plate stage 16 has a plurality of through holes 17, and the through holes 17 are formed so as to be shifted to the right on the lower surface with respect to the upper surface of the stage 16. ), the etching mask 19 provided on the top surface of the stage 16 is formed so as to be shifted to the right with respect to the etching mask 18 provided on the top surface of the stage 16, and etching is performed using the masks 18 and 19. .

A through hole 17 corresponding to the aforementioned through hole 13 is provided in stage 1.
When a semiconductor chip is mounted on 6 and a resin casing is formed, a part of the resin casing is filled.
6 and the resin exterior are firmly bonded, and the bonding strength is equivalent to that using the metal plate stage 12 described above.

〔Effect of the invention〕

As explained above, according to the present invention, by strengthening the bonding force between the stage on which a semiconductor chip is mounted and the resin sheath that seals them, cracks do not occur in the resin sheath when semiconductor devices are mounted with solder. As a result, the performance of semiconductor chips deteriorates due to heating during mounting, and
The effect of eliminating the reduction in lifespan is remarkable.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of a semiconductor device according to an embodiment of the present invention, FIG. 2 is a stage shown in FIG. 1, and FIG. 3 is a sectional view showing an embodiment of a through hole formed in a stage according to the present invention. , Fig. 4 is a side view of a sample for measuring the bonding force between the stage and the resin body, Fig. 5 is a cross-sectional view of the main part of the sample for measuring the bonding force according to the present invention after measuring the bonding force, and Fig. 6 is a side view of the sample for measuring the bonding force between the stage and the resin body. A stage related to a semiconductor device according to another embodiment of the invention, FIG. 7 is a schematic sectional view showing a conventional semiconductor device, FIG. 8 is a schematic diagram showing thermal expansion of a resin exterior in a conventional semiconductor device, and FIG. This is a stage in another conventional semiconductor device. In the figure, 2 is a semiconductor chip, 4 is a sealing resin (resin exterior), 11 is a semiconductor device, 12 and 16 are stages, 13 and 17 are through holes, as shown in Figure 1. Planar view of the stage (A) (Opening) + Front view of main parts of the figure (A) (Opening) Fig. 6 Conventional method A front view of the semiconductor device = 9 "η

Claims (2)

[Claims] (1) A metal plate stage (12) for mounting a semiconductor chip is provided with a plurality of through holes (13) that open larger on the upper surface than the lower surface of the stage (12), and is mounted on the stage (12) and its upper surface. A semiconductor device comprising a semiconductor chip (2) sealed with resin. (2) A metal plate stage (16) for mounting a semiconductor chip has a plurality of through holes (17
), and the stage (16) and the semiconductor chip mounted on the upper surface thereof are sealed with resin.