JPH04320363A - Lead frame, plastic sealed semiconductor device and molding die - Google Patents

Abstract

PURPOSE:To provide a lead frame and a plastic sealed semiconductor device in which the length of wire can be made as short as possible by providing a semiconductor chip mounting part having size optimal for the semiconductor chip. CONSTITUTION:The lead frame for a plastic sealed semiconductor device comprises two cradles 1a, 1b, two tie bars 1c, 1d traversing across the cradles 1a, 1b, and leads 1e crossing with the first tie bar 1c and extending closely to the second tie bar 1d. Stepped leads 1e, leads 1f extending reversely from the leads 1e in adjacent thereto, and an insulating sheet 2 secured to the surfaces of the leads 1e, if while traversing are disposed between the cradles 1a, 1b and the tie bars 1c, 1d.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame, a resin-sealed semiconductor device using this lead frame, and an improvement in a mold for molding this semiconductor device.

[0002] In recent years, semiconductor chips have tended to become larger in size as they become more highly integrated. A lead frame is required.

Under the above circumstances, there is a demand for a resin-sealed semiconductor device using a lead frame having a semiconductor chip mounting portion on which semiconductor chips of various sizes can be mounted.

0004

[Prior Art] A conventional lead frame is shown in FIG. 4, and a conventional resin-sealed semiconductor device is shown in FIG.
A conventional mold will be explained in detail with reference to FIG.

FIG. 4 is a diagram showing a conventional lead frame, FIG. 5 is a diagram showing a conventional resin-sealed semiconductor device, and FIG. 6 is a cross-sectional view of a conventional mold. As shown in FIG. 4, the conventional lead frame 11 has a die stage 11i connected by two cradles 11a and 11b and pinch bars 11g and 11h. book tie bar 11c
and 11d are installed horizontally, and this tie bar 11c
and 11d and connected across the die stage 11i.
Leads 11e and 11f are provided surrounding the die stage 11i and disposed around the die stage 11i.

In a resin-sealed semiconductor device using such a lead frame 11, a semiconductor chip 3 is fixed to a die stage 11i as shown in FIG. A wire 14 is used to connect between the two, and molding is performed using a mold resin 15.

The mold used when molding such a resin-sealed semiconductor device using a mold resin includes an upper mold 16 for molding the upper part of this resin-sealed semiconductor device, as shown in FIG. , and a lower mold 17 for molding the lower part,
As shown in the figure, the upper mold 16 and the lower mold 17 are pressed against the lead frame 11, and molding resin is injected into the mold to mold a resin-sealed semiconductor device.

[0008]

In the conventional resin-sealed semiconductor device described above, semiconductor chips of various sizes are mounted, and the pads of the semiconductor chips and the tips of the leads are brought as close as possible. In order to stably connect these with short wires, it is necessary to manufacture a variety of lead frames with die stages of various sizes that correspond to the size of the semiconductor chip. If you try to mount semiconductor chips of different sizes using a lead frame that has one type of die stage, if you mount a semiconductor chip that is small compared to the size of the die stage, the size of this semiconductor chip will increase. There is a problem in that the length of the wire connecting between the pad and the lead of the lead frame becomes long, resulting in a short circuit between the wires.

In view of the above-mentioned circumstances, the present invention provides a lead frame and a resin seal which are equipped with a semiconductor chip mounting portion of an optimal size for the size of the semiconductor chip and which make it possible to shorten the length of the wire as much as possible. The purpose is to provide a static semiconductor device.

0010

[Means for Solving the Problems] The lead frame of the present invention is a lead frame used for a resin-sealed semiconductor device, and includes two tie bars horizontally disposed between two cradles; A lead that intersects with the first tie bar and extends to the vicinity of the second tie bar, and has a step between the cradle and the tie bar; , a lead extending to the vicinity of the first tie bar and having a step between the cradle and the tie bar, and an insulating sheet horizontally suspended and fixed to the surface of these leads. Configure.

The resin-sealed semiconductor device of the present invention is a resin-sealed semiconductor device using the above-mentioned lead frame, and includes a semiconductor chip fixed to the surface of the insulating sheet, a pad of the semiconductor chip, and the like. The wire is stretched to connect between the leads, and is configured to be resin-sealed using a molding resin.

The molding die of the present invention is a molding die used for resin molding of the above-mentioned resin-sealed semiconductor device, and includes an upper mold for molding the mold resin for the upper part of the resin-sealed semiconductor device, and a lead. The frame is configured to include a lower mold having a recess into which these leads of the frame fit.

[0013]

[Operation] That is, in the present invention, by providing an insulating sheet of the optimum size for the size of the semiconductor chip on the lead frame as a mounting part of the semiconductor chip, the pads of the semiconductor chip mounted on this insulating sheet and the leads of the lead frame This makes it possible to optimize the distance between the wires and prevent short circuits between the wires.

[0014]

[Example] The lead frame of an embodiment of the present invention is shown in FIG. 1, the resin-sealed semiconductor device of an embodiment of the present invention is shown in FIG. 2, and the mold die of an embodiment of the present invention is shown in FIG. 3. This will be explained in more detail below.

FIG. 1 shows a lead frame according to an embodiment of the present invention, FIG. 2 shows a resin-sealed semiconductor device according to an embodiment of the present invention, and FIG. 3 shows a mold according to an embodiment of the present invention. It is a sectional view of a mold.

Lead frame 1 according to an embodiment of the present invention
As shown in FIG. 1, two tie bars 1c and 1d are provided horizontally between two cradles 1a and 1b. The lead 1e is perpendicular to the first tie bar 1c and extends to the vicinity of the second tie bar 1d, and the cradles 1a and 1b, the tie bar 1c
As shown in FIG. 1(b), a step is provided between 1d and 1d.

The leads 1f are alternately adjacent to the leads 1e, are perpendicular to the second tie bar 1d, and are adjacent to the leads 1e.
A step is provided between the cradles 1a and 1b and the tie bars 1c and 1d as shown in FIG. 1(b).

On the surfaces of the leads 1e and 1f, an insulating sheet 2 made of polyimide resin with a thickness of several tens of micrometers is placed horizontally between the leads 1e and 1f, on which the semiconductor chip 3 is fixedly mounted. It is attached by pressure using an acrylic adhesive. The size of this insulating sheet 2 can be selected to be the optimum size corresponding to the size of the conductor chip 3, and for example, it can be set to the size shown by the dotted line in the figure.

A resin-sealed semiconductor device using such a lead frame 1 has a semiconductor chip 3 as shown in FIG.
is fixed to an insulating sheet 2, and the pad 3a of this semiconductor chip 3 and the leads 1e and 1f are connected with wires 4,
It is molded using mold resin 5.

The mold used when molding such a resin-sealed semiconductor device using a mold resin includes an upper mold 6 for molding the upper part of this resin-sealed semiconductor device, as shown in FIG. , a lower mold 7 having a recess 7a that fits with the leads 1e and 1f molding the lower part of the resin-sealed semiconductor device;
The upper mold 6 and the lower mold 7 are pressed against the cradle and tie bar of the lead frame, and molding resin is injected into the mold to mold a resin-sealed semiconductor device.

[0021]

[Effects of the Invention] As is clear from the above description, according to the present invention, by simply changing the configuration, a lead frame having a mounting portion optimal for the size of the semiconductor chip is used, and the pads of the semiconductor chip and the lead frame can be easily adjusted. Since it is possible to optimize the distance between the wires and the leads, it is possible to prevent problems such as short circuits between wires, and since it does not have a metal die stage, it is possible to prevent the mold resin from thermal stress during mounting. It has the advantage of being able to prevent the occurrence of cracks, and since most of the leads are fixed with molded resin, it is also possible to prevent lead deformation, and is expected to have significant economic and reliability effects. It is possible to provide lead frames, resin-sealed semiconductor devices, and molds that can be used.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a lead frame of an embodiment according to the present invention,

FIG. 2 is a diagram showing a resin-sealed semiconductor device according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view of a mold according to an embodiment of the present invention;

[Figure 4] Diagram showing a conventional lead frame,

[Figure 5]
A diagram showing a conventional resin-sealed semiconductor device,

[Figure 6]
Cross-sectional view of a conventional mold,

[Explanation of symbols]

1 is the lead frame, 1a is the cradle, 1b is the cradle, 1c is the tie bar, 1d is a tie bar, 1e is lead, 1f is lead, 2 is an insulation sheet, 3 is a semiconductor chip, 3a is a pad, 4 is wire, 5 is mold resin, 6 is the upper mold, 7 is the lower mold, 7a is a recess;

Claims (3)

[Claims] 1. A lead frame used for a resin-sealed semiconductor device, comprising two cradles (1a) and (1).
b) Two tie bars (1c) and (1d) provided horizontally between a lead (1e) having a step between the cradles (1a) and (1b) and the tie bars (1c) and (1d); and the second tie bar (1d) adjacent to the lead (1e).
and a lead (1f) extending to the vicinity of the first tie bar (1c) and having a step between the cradles (1a) and (1b) and the tie bars (1c) and (1d); A lead frame (1) comprising: an insulating sheet (2) that is fixed horizontally to the surfaces of the leads (1e) and (1f). [Claim 2] A lead frame (1) according to Claim 1.
A resin-sealed semiconductor device using a semiconductor chip (3) fixed to the surface of the insulating sheet (2), a pad (3a) of the semiconductor chip (3), and the leads (1e) and (1f). ) and a molded resin (5).
A resin-sealed semiconductor device characterized in that it is resin-sealed using. 3. A mold used for resin molding of the resin-sealed semiconductor device according to claim 2, comprising: an upper mold (
6) and the lead (1e) of the lead frame (1).
, 1f) is provided with a recess (7a) into which the lower mold (7) is fitted.
A mold comprising: