JP2001210757A - Resin sealed semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin sealed semiconductor element which can suppress cracks and improve the reliability or yield. SOLUTION: The semiconductor element comprises a resin block in which the semiconductor element is sealed with a resin, outer leads for connecting the semiconductor element to externals, and heat sink provided on the backside of the resin block, and two or more trenches continuous from end to end are formed on the surface of the resin block.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-encapsulated semiconductor device, and more particularly, to a resin-encapsulated semiconductor device having a heat radiating plate on the back surface.

[0002]

2. Description of the Related Art As shown in FIG. 7, for example, as shown in FIG. 7, a resin-encapsulated semiconductor element in which a semiconductor element is encapsulated with a resin is formed by covering a semiconductor element (pellet) 1 mounted on a lead frame. 2, a part of the lead frame, an outer lead 3 for connecting the semiconductor element (pellet) 1 to the outside, and a heat radiating plate 4 fixed to the back surface of the resin portion 2. With such a configuration, the semiconductor element is hardly affected by the atmosphere of the outside world, and can efficiently release the heat generated during driving.

The resin part 2 sets a semiconductor element connected to a lead frame by a gold wire or the like in a mold, and
The temperature is raised to about 0 ° C., and a liquefied, low-stress, low-viscosity thermosetting resin is pressure-fed, poured, and cured to form. At this time, a stress is generated due to a difference between the temperature of the mold and the air temperature, and a warp is generated in the longitudinal direction of the resin portion 2. At this time, stress is applied to the resin portion 2 and the semiconductor element (pellet) 1 disposed at the center thereof, and pellet cracks and the like are generated, which causes a reduction in product reliability and a reduction in yield.

[0004]

As described above, the conventional resin-encapsulated semiconductor element has a problem that the surface is warped, so that cracks are generated due to the stress applied when the substrate is mounted.

Accordingly, the present invention provides a resin-encapsulated semiconductor device which eliminates such drawbacks of the conventional resin-encapsulated semiconductor device and can improve reliability and yield without causing cracks. It is intended to do so.

[0006]

According to the present invention, there is provided a resin-encapsulated semiconductor device, comprising: a resin portion in which the semiconductor device is sealed with a resin; an outer lead for connecting the semiconductor device to the outside; and a back surface of the resin portion. And a heat sink provided on the surface of the resin portion, wherein two or more grooves continuous from end to end are provided on the surface of the resin portion.

Further, in the resin-encapsulated semiconductor device according to the present invention, the groove is provided in parallel with a short direction of the resin portion. Further, in the resin-encapsulated semiconductor device according to the present invention, the groove is formed at a position of 15 to 35% of a longitudinal length of the resin portion from an end of the resin portion. Things.

Further, in the resin-encapsulated semiconductor device according to the present invention, the width of the groove is at least 1% and at most 3% of the longitudinal length of the resin portion. It is.

Further, in the resin-encapsulated semiconductor device of the present invention, the depth of the groove is 2 to 15% of the thickness of the resin portion.
It is characterized by being.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS.

First, after mounting the semiconductor element 1 on a lead frame, the semiconductor element 1 and the lead frame are bonded by a gold wire. This is set in the mold,
The liquefied resin is pressure-fed and poured, whereby the semiconductor element 1 is sealed with the resin and the resin portion 2 is formed. The mold is formed in advance so as to form a groove 6 having a trapezoidal cross section.

Thus, FIGS. 1 and 2 show a top view and a side view, respectively, FIG. 3 shows an enlarged view of the groove 6, and FIGS. 4, 5 and 6 show a top view and a longitudinal view, respectively. It shows a side view and a side view in the lateral direction. As shown in these figures, the surface of the resin portion 2 has a depth of 0.
1 mm (ie, 2.2% of the thickness of the resin part 2) trapezoidal groove 6
Are provided. At this time, the distance from the center of the resin portion 2 to the center line of the groove 6 is 3/3 of the length a of the resin portion 2 in the longitudinal direction.
It is 0%. The width of the groove 6 is 2.8% of the length a on the surface of the resin portion.

When the amount of warpage of the surface of the resin portion 2 thus formed is measured by a surface roughness meter, the warpage is clearly reduced in the resin portion 2 provided with the grooves 6 in the present embodiment. The warpage of the conventional one was several tens of μm, whereas in the present invention, the warp was 10 to 20 μm.
μm has been reduced. Further, a heat sink 4 made of Cu material
Was mounted with a screw at the screwed portion 5 to form a resin-sealed semiconductor element. No crack was observed in the resin and the pellet.

In this embodiment, as shown in FIG. 3, the cross-sectional shape of the groove is trapezoidal. However, the shape is not particularly limited. Even if the bottom surface is a curve such as a semicircle, the bottom surface is a straight line such as a rectangle. Even if it is formed, any shape that can be formed may be used.

The width of the groove is preferably 1% or more of the length a in order to reduce the warpage to the extent that cracks do not occur, while 3% or less of the length a in order to obtain a good sealing state. Is preferred.

Further, the depth of the groove must be such that warpage can be reduced to such an extent that cracks do not occur, and the depth of the groove does not expose the gold wire for bonding the semiconductor element to the surface of the resin portion. However, the thickness is preferably 2 to 15% of the resin part thickness (maximum package thickness). It is more preferably at least 5%, and optimally around 10%.

It is preferable that such grooves are respectively parallel to the short side direction, and that one groove having a length a from the end of the resin portion.
It is preferably formed at a position of 5 to 30%. Further, it is preferable that each of the resin portions is formed at a position having the same distance from the center, but a variation within a tolerance is allowed (1% or less of a). In the present embodiment, 2
Although the number of grooves is formed, the number is not particularly limited as long as the grooves are formed so as not to affect the sealing state, and preferably are symmetric.

If the continuity of the groove is not hindered, a deformed portion 7 as shown in FIGS. 1 and 4 may be formed in a part of the groove.

[0019]

According to the present invention, it is possible to provide a resin-encapsulated semiconductor device capable of improving reliability and yield without cracking.

[Brief description of the drawings]

FIG. 1 is a top view of a resin-encapsulated semiconductor device according to an embodiment.

FIG. 2 is a longitudinal side view of the resin-encapsulated semiconductor element of the embodiment.

FIG. 3 is an enlarged view of a groove 6;

FIG. 4 is a top view of the resin-encapsulated semiconductor element of the embodiment.

FIG. 5 is a longitudinal side view of the resin-encapsulated semiconductor element of the embodiment.

FIG. 6 is a lateral view of the resin-encapsulated semiconductor element of the embodiment in a lateral direction.

FIG. 7 is a top view and a side view showing a conventional resin-encapsulated semiconductor element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor element (pellet) 2 Resin part 3 Outer lead 4 Heat sink 5 Screw fastening part 6 Groove 7 Deformed part of groove

Claims (6)

[Claims] 1. A resin part in which a semiconductor element is sealed with a resin, an outer lead for connecting the semiconductor element to the outside, and a radiator plate provided on a back surface of the resin part. A resin-encapsulated semiconductor element, wherein two or more continuous grooves are provided from end to end. 2. The resin-encapsulated semiconductor device according to claim 1, wherein said groove is provided in parallel with a lateral direction of said resin portion. 3. The resin-encapsulated semiconductor device according to claim 1, wherein the groove is provided substantially symmetrically with respect to a center of the resin portion. 4. The resin sealing device according to claim 1, wherein said groove is formed at a position of 15 to 35% of a longitudinal length of said resin portion from an end of said resin portion. Stop type semiconductor element. 5. The resin-encapsulated semiconductor device according to claim 1, wherein a width of the groove is 1% or more and 3% or less of a length of the resin portion in a longitudinal direction. . 6. The depth of the groove is 2 to 1 of the thickness of the resin portion.
The resin-encapsulated semiconductor device according to claim 1, wherein the content is 5%.