JPH0554264B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a resin package type semiconductor device.

[Prior Art] As shown in FIG. 1A, a resin package type semiconductor device is manufactured by fixing a chip 3 on a central tab 2 of a lead frame 1, and then attaching a large number of leads 4 whose inner ends face around the tab 2. The inner end of the chip 3 is connected to the electrode of the chip 3 with a wire 5, and then, as shown in FIG. , by cutting and removing unnecessary lead frame parts.

By the way, in order to increase the number of external terminals (leads) and reduce the size, a resin package type semiconductor device in which leads are made to protrude in four directions in the plane X and Y directions is known, for example, from Japanese Patent Laid-Open No. 55-21128. ing.

[Problems to be Solved by the Invention] In this type of semiconductor device, as shown in FIG. ) will be provided at one corner of the lead frame 1. Further, since the support plates 9 that support the leads 4 and the dams 8 are also located at the four corners of the lead frame 1, the gate 7 overlaps with this one support plate 9. For this reason, as shown in FIG. 3, the support plate 9 extends to the middle of the gate 7, and when the gate breaks after resin molding, the support plate 9 is secured at the boundary between the resin part hardened in the gate 7 and the resin package 6. The rupture is no longer performed in the fourth
A defect called gate residue as shown in FIGS. a to c occurs.

According to the invention disclosed in Japanese Patent Application Laid-Open No. 55-21128, the resin is intentionally broken (gate break) as shown in FIG. 4b, but the remaining gate remains unavoidable.

Generally, a mold is designed so that the hardened resin part at the tip of the gate 7 is the thinnest, and when the gate breaks, rupture occurs at this thin boundary part due to stress concentration. However, since the end face of the support plate 9 is formed by punching, it has a rough surface and has high adhesion with the resin, so the gate break occurs on the inside of the support plate 9 (see Fig. 4). a), the edge of the support plate 9 (see Fig. 4b), and a crack 1 at the boundary.
0 is entered, but the break may also be performed inside the support plate 9 (see FIG. 4c), as in FIG. 4a.
If there is any remaining gate in this way, the remaining gate portion may fall off due to vibrations during transportation, and may get caught between the transportation table and the resin package cage 6 or lead frame 1, causing damage to the resin package cage 6. The lead frame may become deformed. This causes failures such as product clogging in the lead cutting and forming machine.

Therefore, in the past, it was also necessary to remove the remaining gates and the fallen resin pieces, which degraded the workability in the resin mode.

Therefore, an object of the present invention is to improve the productivity of semiconductor devices by ensuring that the gate resin portion is broken at the edge of the resin package at the time of gate failure.
The purpose is to improve yield.

[Means for Solving the Problems] According to the present invention, the semiconductor chip has a table to which a semiconductor chip is attached, an end portion that is close to the tab and makes electrical connection with an electrode of the semiconductor chip, and has a radial shape in four directions. preparing a lead frame having a plurality of lead groups extending across the lead frame, a dam supporting the lead groups, and a wide frame portion connected to a portion of the dam; A step of mounting the chip and electrically connecting the electrode of the semiconductor pellet and the lead end with a wire, the semiconductor chip, the wire, and the lead end to which the wire is connected are placed in the mold using a pair of upper and lower molds. A method for manufacturing a semiconductor device, comprising the step of encapsulating a rectangular resin package body by injecting resin through a gate runner and a gate provided, the method comprising the step of: sealing the package body with a rectangular resin package body, the method comprising: A runner and a fan-shaped gate having a diameter smaller than that of the gate runner and having an inclined and tapered diameter are continuously provided along the flat surface of the other mold of the mold,
The prepared lead frame has the wide frame portion located at a corner of the rectangular resin package body on which the mold is formed, corresponding to the gate runner and gate of the one type, and the wide frame portion has the above-mentioned wide frame portion. It has a fan-shaped notch that is wider than the gate width of one type, and the end of the notch is located within the gate runner, and in the step of sealing with the rectangular resin package body, the lead frame is and injecting resin into the mold part through the gate runner and gate of the mold, and then removing the resin-sealed lead frame from the mold and inserting the resin into the corner of the resin package body. This method is characterized by breaking a resin portion corresponding to the tapered diameter of the gate.

According to this configuration, the resin of the gate part is located at the edge of the corner of the resin package body, and when the resin breaks, stress concentrates on the thin gate resin at the corner, making it easy to break the gate at that part. will be ensured. In other words, the thinnest part of the gate resin in the thickness and width direction is at the corner of the package body, while the end of the notch is located within the gate runner, and is the thinnest part of the gate part in the width direction. The part is the corner edge of the package body, and the gate break will surely occur from that part.

[Embodiment] FIG. 5 is a plan view showing a method of manufacturing a resin molded semiconductor device according to an embodiment of the present invention, particularly showing the state of the resin mold. In the lead frame 1 of this embodiment, a pair of first frame parts 11a, 11b are located apart from each other, and a pair of second frame parts are located apart from each other and are connected to the first frame parts 11a, 11b. 11c and 11d. Then, these first frame parts 11a, 11b and the second frame part 1
In the portion defined by 1a and 11b, the lead 4 is supported by a dam 8 extending in the shape of a rectangular frame. In addition, a rectangular frame dam 8
The four corners of the lead frame 1 are supported by support plates 9 to the frame 11 of the lead frame 1 .

In the mold used for the resin mold (indicated by the hardening state of the injected resin in the figure),
A gate runner 12 of the mold is provided along the support plate 9 at one corner. This support plate 9 is a single plate so that the resin can flow out smoothly. Further, as shown in FIGS. 6 and 7, the gate runner 12 is arranged so that a part of the wide support plate 9a is not located in the part corresponding to the gate 7 of the mold which is tapered from the gate runner 12. The support plate 9 is cut out and bifurcated from a portion corresponding to the tip of the support plate 9 . That is, as shown in FIG. 6, a fan-shaped notch is provided in the support plate 9 forming a wide frame portion so as to extend to a position corresponding to the gate runner. There is a mold cavity that is connected to this gate 7 and forms a resin-sealed external structure.
The branch pieces 13 extend apart from each other along both sides of the gate 7 and are connected to the respective ends of the dam 8. Therefore, the dam portions corresponding to the gates 7 are connected via one branch piece 13, the support plate 9, and the other branch piece 13, without directly contacting each other. On the other hand, as can be understood from the mold configuration shown in Figure 7, the shape of the mold used is smaller in diameter than the gate runner of the mold, and the gate, which has an inclined and tapered diameter, is located under the mold. It is located continuously on the side.

For this reason, as shown in FIG. 7, the support plate 9 has a fan-shaped notch that is wider than the gate width and the end of the notch is located inside the gate runner. The edge of the gate 7 separates from the gate 7 and is located inside the wide and thick gate runner, and when the gate breaks after resin molding, the tip of the gate 7, which is the boundary with the resin package 6, is removed as shown in Figure 8. Since the stress concentration is the largest, it breaks at this boundary and is no longer involved in the adhesion between the support plate 9 and the resin as in the past, and gate break failures no longer occur.

In addition, in the lead frame 1 of the present invention, in order not to reduce the strength after resin molding, the branch piece 13 of the support plate 9 is attached to the gate runner 12, which has strong resin strength.
are arranged so that they partially overlap.

According to such an embodiment, the runner breaking operation after resin molding becomes reliable, and cleaning of the mold etc. becomes easy, so that the molding operation is improved by about 1.4 times. In addition, since the lead frame does not deform when the runner breaks, there is no chance of product clogging in the automatic machine during the lead cutting and forming process.
It becomes possible to prevent the occurrence of defects.

[Effects of the Invention] As described above, according to the present invention, the lead frame has a pattern that ensures that the gate resin portion breaks at the edge of the resin package during gate break after resin molding. Break failures no longer occur.

As a result, it is no longer necessary to remove the remaining gate parts and the resin pieces that have fallen off due to the falling off of the remaining gate pieces, improving workability of the resin mold, and improving yield by preventing defects caused by falling resin pieces. can be achieved.

[Brief explanation of the drawing]

1A and 1B are cross-sectional views showing a method for manufacturing a semiconductor device, FIG. 2 is a plan view showing a conventional method for manufacturing semiconductors, FIG. 3 is a partial cross-sectional view of the same, and FIGS.
Similarly, FIG. 5 is a sectional view showing a method of manufacturing a semiconductor device according to an embodiment of the present invention, FIG. 6 is a partially enlarged plan view of the present invention, and FIG. The diagram is in Figure 6-
FIG. 8 is a sectional view taken along the line, and is a partial sectional view showing the state after the gate break. 1...Lead frame, 11a, 11b...First frame portion, 11c, 11d...Second frame portion, 2...Tab, 4...Lead, 6...Resin package cage, 7
...Gate, 8...Dam, 9,9a...Support plate,
10... crack, 12... gate runner, 13
...Branch piece.

Claims (1)

[Scope of Claims] 1. A tab to which a semiconductor chip is to be attached, and a plurality of lead groups extending radially in four directions, each having an end close to the tab and electrically connected to an electrode of the semiconductor chip; preparing a lead frame having a dam for supporting the lead group and a wide frame portion connected to a part of the dam; mounting a semiconductor chip on a tab of the lead frame; A step of electrically connecting the electrode and its lead end with a wire, the semiconductor chip, the wire, and the lead end to which the wire is connected are passed through a gate runner and a gate provided in the mold using a pair of upper and lower molds. A method for manufacturing a semiconductor device, comprising the step of sealing with a rectangular resin package body by injecting resin, wherein one of the molds used includes a gate runner and a gate runner having a diameter larger than that of the gate runner. A fan-shaped gate having a small diameter and an inclined tapered diameter is continuously provided along the flat surface of the other mold,
The prepared lead frame has the wide frame portion located at a corner of the rectangular resin package body on which the mold is formed, corresponding to the gate runner and gate of the one type, and the wide frame portion has the above-mentioned wide frame portion. It has a fan-shaped notch that is wider than the gate width of one type, and the end of the notch is located within the gate runner, and in the step of sealing with the rectangular resin package body, the lead frame is and injecting resin into the mold part through the gate runner and gate of the mold, and then removing the resin-sealed lead frame from the mold and inserting the resin into the corner of the resin package body. A method for manufacturing a semiconductor device, characterized by breaking a resin portion corresponding to the tapered diameter of a gate.