JPH03152964A - Resin sealed type semiconductor device lead frame - Google Patents

Abstract

PURPOSE:To prevent an electric short circuit due to the deformation of an inner lead so as to improve a semiconductor device in yield by a method wherein a part of the inner lead, which is located inside a tie bar and comes into contact with a resin sealing mold when the semiconductor device is sealed up with resin, is formed smaller than the tie bar in thickness. CONSTITUTION:A groove 10 is provided to the underside of a part of an inner lead 3 which is located inside a tie bar 9 and comes into contact with a resin sealing mold 7 to make the part concerned smaller than the tie bar 9 in thickness. When a semiconductor device is manufactured using the lead frame formed as above, even if a foreign object such as sealing resin or the like is attached to the clamping face of the mold 7, a force applied to the lead 3 inside the tie bar 9 is small at clamping, so that the lead 3 is prevented from being deformed. Therefore, an electric short circuit due to the deformation of an inner lead can be restrained, in result a semiconductor device can be improved in yield.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lead frame for a resin-sealed semiconductor device.

[Conventional technology]

Conventionally, resin-sealed semiconductor devices, as shown in FIG.
The semiconductor element 2 is mounted on the element mounting part 1 of the lead frame, the semiconductor element 2 and the internal leads 3 are connected with a thin metal wire 4, the periphery of the element mounting part 1 is sealed with a sealing resin 5, and then,
This is completed by molding the external leads 6.

[Problem to be solved by the invention]

The conventional technology described above has the following problems when manufacturing a semiconductor device using a lead frame with thin internal leads.

In FIG. 5, if there are 50 internal leads 3 to be connected to one side 5IIIll of the semiconductor element 2, the thickness of the tips of the internal leads must be 51500.1 mm by simple calculation. Such a thin internal lead 3 is highly likely to be deformed when it is clamped by a resin sealing mold. That is, as shown in FIG. 6, even if the resin molding die 7 has foreign matter 8 such as molding resin so minute that it cannot be seen with the naked eye, such thin internal leads 3 The inner leads 3 may be deformed due to shadowing, and the inner leads 3 may come into contact with each other as shown in FIG. A semiconductor device in which sealing resin is injected in such a state becomes an electrically defective product.

As described above, in the conventional technology, when manufacturing a semiconductor device having thin internal leads, there is a problem in that there is an extremely high risk of producing defective products due to short-circuits between internal leads.

An object of the present invention is to provide a lead frame for a resin-sealed semiconductor device that does not produce defective products due to short circuits between leads.

[Means to solve the problem]

In the resin-sealed lead frame for a semiconductor device of the present invention, at least the portion of the internal lead inside the tie bar that contacts the resin sealing mold during resin sealing is thinner than the tie bar.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a partial plan view of the first embodiment of the present invention, and FIG. 2 is a view taken along A-A when the lead frame in FIG. 1 is being clamped.
FIG.

In the first embodiment, as shown in FIG. 1 and FIG.
There is a groove 10 on the lower surface of the part that contacts the tie bar 9, and the thickness of this part is thinner than the tie bar 9. Since the depth of this groove 10 is 50 μm, the thickness of the tie bar 9 is 250 μm.
If it is μm, then the internal lead 3 of this thinned part
The thickness is 200 μm.

When manufacturing semiconductor devices using such a lead frame, even if foreign matter such as sealing resin adheres to the clamping surface of the resin-sealed mold 7, the tie bars should be removed during mold clamping. Since the force applied to the internal lead 3 on the inside of 9 is small,
The internal leads 3 are not deformed.

FIG. 3 is a partial sectional view of the lead frame according to the second embodiment of the present invention when the mold is being clamped.

As shown in FIG. 3, the second embodiment differs from the first embodiment in that, of the leads inside the tie bar 9, not only the lower surface but also the upper surface of the portion that contacts the resin molding mold 7 is used. A groove 10 is provided on each side. The depth of this groove 10 is 50 μm on both the upper surface side and the lower surface side, so the tie bar 9
If the thickness of the internal lead 3 is 250 μm, the thickness of this thinned portion of the internal lead 3 is 150 μm.

This has the advantage that deformation of the internal leads 3 can be more effectively prevented even when foreign matter is attached to the clamping surface of the upper mold as well as the lower mold of the resin sealing mold 7. There is.

〔Effect of the invention〕

As explained above, the present invention makes it possible to reduce the amount of electricity caused by deformation of the internal lead by making at least the part of the internal lead inside the tie bar that contacts the resin sealing mold thinner than the thickness of the tie bar during resin sealing. This has the effect of reducing the occurrence of target shorts and improving yield.

In addition, even if some foreign matter adheres to the mold clamping surface of the resin sealing mold, the internal leads will not be deformed, making cleaning the sealing mold simpler and easier than before. It also has the effect of improving sex.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of the first embodiment of the present invention, and FIG. 2 is a view showing l-A when the lead frame of FIG.
3 is a partial sectional view when the lead frame of the second embodiment of the present invention is being clamped, and FIG. 4 is a sectional view of an example of a conventional resin-sealed semiconductor device. FIG. 5 is a partial plan view for explaining the problems of the conventional internal lead.
FIG. 6 is a partial cross-sectional view for explaining problems when mold-clamping a conventional lead frame, and FIG. 7 is a partial plan view for explaining an example of modification of the conventional internal lead. DESCRIPTION OF SYMBOLS 1... Element mounting part, 2... Semiconductor element, 3... Internal lead, 4... Metal thin wire, 5... Sealing resin, 6...
... External lead, 7... Resin sealing mold, 8... Foreign matter, 9... Tie bar 10... Groove.

Claims (1)

[Claims] A lead frame for a resin-sealed semiconductor device, characterized in that at least a portion of the internal leads inside the tie-bar that contacts a resin-sealing mold during resin-sealing is thinner than the thickness of the tie-bar.