JPH05291473A - Plastic sealed semiconductor device and leadframe for use with it - Google Patents

Abstract

PURPOSE:To improve a geometrical strength of a plastic sealed semiconductor device, and to prevent cracks in resin when a semiconductor device is mounted as well as the occurrence of shifts of a die pad when it is encapsulated with resin. CONSTITUTION:Triangular projections 12 are formed at the center of a die pad plate 11 on which a semiconductor chip 1 is fixed by an adhesive 3. In addition, a plurality of leads 5 are fixed to each side of the plate via an insulating tape 14. The plate is then encapsulated with resin 7 such that a part of the projection 12 is completely exposed outside a semiconductor device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a resin-sealed semiconductor device and a structure of a lead frame used for the same.

[0002]

2. Description of the Related Art FIG. 10 is a sectional side view showing a conventional resin-encapsulated semiconductor device, and FIG. 11 is a plan perspective view showing only a part thereof in detail. In the figure, 1 is a semiconductor element having a circuit formed on a silicon surface, and 2 is a die pad to which the semiconductor element 1 is fixed with an adhesive 3, and is supported by a die pad support 4 (see FIG. 11).
Reference numeral 5 is a lead, and 6 is an AU for electrically connecting the wire bonding pad formed on the semiconductor element 1 to the lead 5.
The wire 7 is a sealing resin that is sealed so that one end of the lead 5 is exposed.

The die pad support 4 is shown in FIG.
As shown in, one that is supported by four, two or three
Depending on the type of semiconductor device, such as the one supported by a book, it is supported by various methods.

The resin-encapsulated semiconductor device having this structure will be described in the order of manufacturing steps. The semiconductor element 1 is fixed to the die pad 2 with the adhesive 3. And this semiconductor device 1
The wire bonding pad formed above and the lead 5 are electrically connected by the AU wire 6. After that, the whole is sealed with a sealing resin 7 so that one end of the lead 5 is exposed. Then, the leads 5 protruding from the sealing resin 7
And the die pad support 4 can be cut and bent to obtain a resin-sealed semiconductor device.

[0005]

However, in the resin-encapsulated semiconductor device having the above-mentioned structure, moisture in the air is absorbed in the distribution route such as warehouse storage, and the interface between the encapsulating resin 7 and the die pad 2 and the adhesion thereof. Accumulates as water in Agent 3. Especially, when the sealing resin becomes thinner, the latter effect becomes more significant. Then, the heat 8 when the semiconductor device is mounted on the substrate causes the moisture accumulated in the adhesive 3 to be rapidly vaporized and expanded, and the adhesive 9 expanded by the vapor pressure pushes down the die pad 2 and the sealing resin 7 A crack 10 is generated on the surface (see FIG. 3). The resin crack 10 is generated from the center of the long side when the die pad 2 is rectangular, and from the center of each side when the die pad 2 is square. This is because idiosyncratic stress concentrates on that part. The resin crack 10 causes corrosion of the aluminum wiring portion of the circuit formed on the semiconductor element 1 and may cause the semiconductor device to fail, thus degrading reliability.

According to the present invention, in order to eliminate the above-mentioned problem of resin cracks that deteriorate the reliability of a semiconductor device, a semiconductor element is mounted on a die pad plate having a triangular protrusion at the center of each side. Thus, it is an object of the present invention to provide a highly reliable resin-encapsulated semiconductor device which can improve the mechanical strength and release vapor pressure, prevent the occurrence of resin cracks.

[0007]

SUMMARY OF THE INVENTION A resin-sealed semiconductor device according to the present invention is a flat die pad plate having a triangular protrusion at the center of each side, and a semiconductor fixed to the die pad plate with an adhesive. An element and a plurality of leads fixed to this die pad plate via an insulating tape are provided, and resin sealing is performed so that a part of the triangular protrusion is completely exposed to the outer shape of the semiconductor device.

In the lead frame according to the present invention, the dam bar supporting the leads is provided with a half edge facing the half edge of the support so that the support and the dam bar do not overlap each other.

[0009]

According to the present invention, the mechanical strength is improved, and the generation of resin cracks at the time of mounting on a substrate can be prevented. Further, the die pad plate and several tens of leads are fixed via an insulating tape. Therefore, it is possible to prevent the die pad shift from occurring during resin sealing.

[0010]

1 is a sectional side view showing an embodiment of a resin-sealed semiconductor device according to the present invention, and FIG. 2 is a plan perspective view showing only a part of FIG. 1 in detail. As shown in FIG. 2, reference numeral 11 denotes a die pad plate in which triangular protrusions 12 are provided in the central portions of the respective sides as shown in FIG. 2. The semiconductor element 1 is adhered by an adhesive 3, and the details thereof are shown in FIG. As described above, the lead 5 is adhered via the insulating tape 14 (for example, a thickness of about 25 to 50 μm) having the adhesive 13 applied on both sides.

Incidentally, a part of the triangular projection 12 of the die pad plate 11 reaches the outer shape of the semiconductor device, and moisture is released from this part so that an adhesive agent is applied by heating when mounting the semiconductor device on a substrate. It is possible to avoid the swelling of the water content in No. Further, by providing the triangular protrusions 12 of the die pad plate 11 at the center of each side, it is possible to relieve some kind of stress.

FIG. 4 is a detailed side view of section C of FIG.
In order to expose the tips of the triangular protrusions 12 provided at the central portions of the sides of the die pad plate 11 to the outside of the resin-sealed semiconductor device, the tips should be installed at the same height as the leads 5. , A part of the die pad plate 11 is downset 15. Therefore, the lead 5 and the triangular protrusion 12 can be sandwiched by a mold and resin-sealed. As a result, the triangular protrusions 12 of the die pad plate 11 are exposed to the outside of the resin-sealed semiconductor device, so that the moisture inside can be smoothly discharged in the direction of the arrow 16.

FIG. 5 shows a case where a part of the lead 5 is upset 17, and it goes without saying that the same operation as that shown in FIG. 4 is performed.

When the number of leads 5 provided on one side of the resin-sealed semiconductor device is an odd number, the position of the triangular protrusion 12 of the die pad plate 11 is one support 12A as shown in FIG. And in the case of an even number, two supports 12A and 12B are provided as shown in FIG.
Therefore, the lead 5 and the triangular protrusion 12 do not overlap each other.

The supports 12A and 12B,
The dam bar 19 protrudes from the outer shape by about 0.5 mm or more in the middle of the process.
A support cut 18 is performed together with.

Recently, as semiconductor devices have become thinner,
The position of the dam bar 19 is also short such that the distance to the outer shape of the semiconductor device is 0.2 mm or less, and when the triangular protrusion 12 of the die pad plate 11 is projected, it may overlap with the dam bar 19. Therefore, as shown in FIG. 9, a half edge 19A is provided on the dam bar 19 and the support 1
By providing the half edge 12A-1 also in 2A,
Overlap can be avoided.

[0017]

As described in detail above, according to the resin-sealed semiconductor device and the lead frame used therefor according to the present invention, a triangular protrusion is provided at the center of each side of the die pad plate for fixing the semiconductor element. Since the leads are formed so as not to overlap with the outer shape of the semiconductor device, the mechanical strength is improved, and the die pad plate is shaped to easily release the vapor pressure. It is possible to prevent resin cracks that occur and to improve reliability. Further, not only can the manufacturing process be carried out in the usual process, but the die pad plate is supported by dozens of leads, and the die pad plate itself is also supported by the support, so that the die pad shift occurs during resin sealing. There is no effect.

[Brief description of drawings]

FIG. 1 is a cross-sectional side view showing an embodiment of a resin-sealing type semiconductor device according to the present invention.

FIG. 2 is a plan perspective view showing only a part of FIG. 1 in detail.

FIG. 3 is a detailed side view of a portion A of FIG.

FIG. 4 is a detailed side view of part B of FIG.

5 is a side view showing another embodiment of FIG. 4. FIG.

FIG. 6 is a plan view showing the positions of supports provided on the triangular protrusions when the number of leads is odd.

FIG. 7 is a plan view showing the positions of supports provided on the triangular protrusions when the number of leads is even.

FIG. 8 is a plan view showing a case where an overlap between a dam bar and a support is avoided.

9 is a partially detailed perspective view of FIG. 8. FIG.

FIG. 10 is a cross-sectional side view of a conventional device.

11 is a perspective plan view of FIG.

12 is a side view for explaining FIG. 10. FIG.

[Explanation of symbols]

 11 Die pad plate 12 Triangular protrusion 14 Insulating tape 19 Dam bar

Claims (4)

[Claims] 1. A flat plate-shaped die pad plate having a triangular protrusion at the center of each side, a semiconductor element fixed to the die pad plate with an adhesive, and a plurality of semiconductor elements fixed to the die pad plate via an insulating tape. A resin-sealed semiconductor device comprising a lead and resin-molded so that a part of the triangular protrusion is completely exposed to the outer shape of the semiconductor device. 2. The part of the die pad plate is down-set or the part of the lead is up-set, and the heights of the tip of the triangular protrusion and the outer end of the lead are the same. Resin-sealed semiconductor device. 3. The tip of the triangular protrusion of the die pad plate is provided on the tip of the triangular protrusion by the number of leads provided on one side of the semiconductor device being an odd number or an even number so that the tip does not overlap the lead at the exposed portion. The resin-sealed semiconductor device according to claim 2, wherein the position of the support is changed. 4. A lead frame, wherein a half edge is provided so as to oppose a half edge provided on a support of a dam bar that supports a lead so that the support and the dam bar do not overlap each other.