JP3109919B2 - Method for manufacturing resin-encapsulated semiconductor device and mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a resin-encapsulated semiconductor device for encapsulating a semiconductor assembly with a resin-molded die, and a die thereof.

[0002]

2. Description of the Related Art Conventionally, rectifier diodes, transistors,
A semiconductor chip (2) such as a thyristor or an IC is placed on a metal support plate, and a semiconductor assembly is formed together with connectors and other components. The semiconductor assembly is sealed with an epoxy resin or the like, and a plurality of semiconductor assemblies are externally mounted. There is known a resin-sealed semiconductor device in which a lead piece is led out.

As means for mass-producing a plurality of such components, a semiconductor assembly and a semiconductor assembly using a lead frame in which an external lead piece, an internal lead piece, a metal support plate and the like are connected to a frame. An external lead is formed, and resin molding is performed by a transfer mold method or the like using a resin mold, and thereafter, no separate lead frame is required as if the individual semiconductor devices were separated. Manufacturing methods for cutting parts are known.

FIGS. 1A and 1B are assembly structure diagrams of a conventional resin-encapsulated semiconductor device using a lead frame, wherein FIG. 1A shows a single-in-line type and FIG. 1B shows a dual-in-line type. 1
Is a lead frame, 2 is an external lead piece, 3 is a tie bar,
4 is a frame, and 5 is a sealing resin. Although not shown, a semiconductor assembly is formed and accommodated in the sealing resin 5 by a metal support plate, a connector and the like of the lead frame 1. 1 (a) and 1 (b) each show one semiconductor device immediately after resin molding, and usually a large number of semiconductor devices are connected to the lead frame 1. FIG.

The tie bar 3 is provided at the base of the external lead piece 2, that is, in the vicinity of the sealing resin 5, and serves to prevent the resin from flowing out when the resin is injected. However, after resin sealing, tie bar-3 is an unnecessary part, and is cut and removed.

FIG. 2 is a structural view of the lead frame 1 after the tie bar 3 and the frame 4 have been removed. The same reference numerals as those in FIG. 1 denote the same parts. Since the tie bar 3 is cut in the vicinity of the sealing resin 5, a mechanical stress is applied to the sealing resin 5, and damage such as cracks may be left.

FIG. 3 is an enlarged view of a tie-cut portion of the external lead piece, and it is inevitable that a slight (3) step is generated in the cut portion. In addition, as shown in FIG.
In addition to the one where the cut part is a convex part to the external lead piece,
There are also steps forming concave portions.

[0008]

When the tie bar is cut,
Problems to be solved are that damage such as cracks may be left in the sealing resin, and that the external lead piece cannot be cut linearly and a step occurs.

[0009]

Means for Solving the Problems The present invention provides (1) a plate shape,
Alternatively, a rod-shaped fast-curing thermosetting resin material is mounted in a recess provided in the upper or lower die so as to be in the vicinity of a space of the external lead piece lead-out portion of the resin mold and before the resin injection. In addition, a manufacturing method in which a fast-curing thermosetting resin material surrounds each external lead piece by bonding the heated upper mold and lower mold to prevent the resin from flowing out during resin injection. (2) In the above item (1),
The mounting of the quick-curing thermosetting resin material into the concave portion provided in the upper mold or the lower mold at the time of setting the lead frame to the mold. (3) A mold used in the production method according to the above (1) or (2). As a result, a resin-encapsulated semiconductor device having high reliability and good appearance can be manufactured by using a lead frame having no tie which causes a problem.

[0010]

4A and 4B show an assembly structure of a resin-sealed semiconductor device according to an embodiment of the present invention. FIG. 4A shows a single-in-line type and FIG. 4B shows a dual-in-line type. The same reference numerals as those in FIG. 1 indicate the same parts, and similarly to FIG. 1, one semiconductor device immediately after resin molding and before cutting the lead frame 1 is illustrated. FIG. 4 is characterized in that tie bar-3 does not exist as shown in FIG.

FIGS. 5A and 5B are main process charts for explaining the manufacturing method of the present invention. FIG. 5A is a process chart before the upper mold and the lower mold (4) are joined, and FIG. FIG. 4C is a cross-sectional view taken along the line A-A ′, FIG. 4C is a process diagram when the upper die and the lower die are joined, and FIG. In the figure, 6 is a semiconductor chip, 7 is a connector, 8 is an upper mold of a resin mold, 9 is a lower mold, 10 is a thermosetting thermosetting resin material, 11 is a space in the mold, 12 Is an external lead piece lead-out portion of the die, and 13 is a concave portion of the lower die 9.

The resin mold according to the present invention comprises an upper die 8 and a lower die 9. The upper die 8 or the lower die 9 is provided with a quick-curing thermosetting resin material, so that the upper die 8 or the lower die 9 is empty. A recess 13 is provided in the external lead piece lead-out portion 12 near the place 11. That is, the concave portion 13 is formed over the external lead piece lead-out portion 12 near the position where the conventional tie bar should exist.

The quick-curing thermosetting resin material 10 is, for example,
It is obtained by blending an epoxy-based, silicon-based, or Teflon-based resin or adjusting a curing agent, and forms a plate or a rod. Further, for example, a material which is rapidly cured by heating at about 170 ° C. is preferable, and further, it is desirable that the adhesiveness to other sealing resin materials and external lead pieces is low and the releasability is high.

As shown in FIGS. 5 (a) and 5 (b), the lead frame 1 forming an assembly of the semiconductor chip 6, the connector 7, etc.
At the same time, the quick-curing thermosetting resin material 10 is set in the recess 13. Resin material 10 into recess 13
Is performed prior to the setting of the lead frame 1.

Next, as shown in FIGS. 5 (c) and 5 (d), the heated upper die 8 and lower die 9 are joined, and a sealing resin is injected into the space 11 from a gate opening (not shown). In this case, the quick-curing thermosetting resin material 10 is in a molten state for a moment,
As shown in FIG. 5 (d), (5) the outer lead piece 2 is surrounded and hardened rapidly to prevent the resin from flowing out.

Next, after molding the sealing resin, the semiconductor device is taken out of the mold. At this time, the resin material 10 attached to the external lead pieces 2 is removed by pressing. Although the attached resin material 10 may be removed so as to remain on the concave portion 13 side,
In that case, a step of removing before the next molding step is required.

According to the present invention, the conventional tie bar is not required, but a wire for connecting the external lead piece to a position separated from the sealing resin so as not to adversely affect the sealing resin at the time of cutting. It is obvious that the present invention can be practiced by using a lead frame for providing convenience in manufacturing and handling.

According to the manufacturing method and the mold of the present invention, the lead frame without the tie bar is used to prevent the injected resin from flowing out of the external lead piece portion and to separate the semiconductor devices into individual semiconductor devices. Low mechanical stress on the sealing resin,
In addition, the outer lead piece can be formed linearly.

The resin material 10 is mounted on the lower mold 9 as in the embodiment.
The upper die 8 is not limited to the concave portion 13 and may be provided with a concave portion. The concave portion 13 is a concave portion required when the resin material 10 is mounted, and it is within the scope of the present invention to provide a concave portion for another purpose in the upper die or the lower die on the side facing the concave portion 13. Furthermore, the embodiments of the present invention can be variously modified, changed, added, and so forth within the scope of the present invention.

[0020]

As described above, the present invention provides a method of manufacturing a resin-encapsulated semiconductor device having high reliability, good appearance, and economical efficiency, and a die. 6) and the like, and its industrial effects,
Extremely large.

[Brief description of the drawings]

FIG. 1 is an assembly structure diagram of a conventional resin-encapsulated semiconductor device using a lead frame, wherein FIG.
(B) is a dual line type.

FIG. 2 is a structural view of a lead frame after the tie bar and the frame are removed.

FIG. 3 is an enlarged view of a tie bar cutting portion.

FIG. 4 is an assembly structure diagram according to an embodiment of the present invention, in which (a) is a single-in-line type and (b) is a dual-in-line type.

FIG. 5 is a main part process drawing explaining the manufacturing method of the present invention,
(A) is a process diagram before joining the upper mold and the lower mold, and (b) is (a)
7A is a sectional view taken along the line AA ′, FIG. 7C is a process diagram when the upper mold and the lower mold are joined, and FIG. 7D is a sectional view taken along the line AA ′ of FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 lead frame 2 external lead piece 3 tie bar 4 frame 5 sealing resin 6 semiconductor chip 7 connector 8 upper mold of resin mold 9 lower mold of resin mold 10 Fast-curing thermosetting resin material 11 Mold cavity (7) 12 External lead piece lead-out section 13 Mold recess

Claims (1)

(57) [Claims] 1. A semiconductor chip is mounted on a lead frame.
The lead frame and the semiconductor chip are connected by connectors.
Consisting of an upper mold and a lower mold with a space for resin sealing
In a method of manufacturing a resin-encapsulated semiconductor device in which resin is encapsulated by a resin mold , a plate-shaped or rod-shaped fast-curing thermo-effective resin is placed near an empty space of an external lead piece of the resin mold. Provided on one or both of upper and lower molds
Is mounted in the recess, when the resin injection, by by coupling the heated upper and lower molds, fast curing type thermosetting resin material is cured in a state of surrounding each external lead pieces, during resin injection A method for manufacturing a resin-encapsulated semiconductor device, characterized in that the resin is prevented from flowing out.