JPH06244352A - Lead frame and manufacturing method for semiconductor device - Google Patents

Abstract

PURPOSE:To provide a lead frame including a dam bar capable of sealing all spaces between leads supported by a resin sealing die in a resin sealing step and making a cutting step unnecessary after the resin sealing. CONSTITUTION:A strip-shaped resin member made of thermoplastic resin is used as a dam bar 10. The dam bar 10 has a plurality of groove parts for inserting leads 12, which constitute a lead frame.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame and a method for manufacturing a semiconductor device, and more particularly to a lead frame having a dam bar at the boundary between an inner lead and an outer lead, and a semiconductor using the lead frame. The present invention relates to a method of manufacturing a device.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional lead frame. In the lead frame 100 shown in FIG. 5, the outer leads 1 are attached to the inner leads 102 ...
04 are provided. Further, a dam bar 110 is provided at the boundary between the inner lead 102 and the outer lead 104. When manufacturing a semiconductor device using the lead frame 100, after wire bonding the electrode of the semiconductor chip mounted on the stage 120 and the tip of the inner lead 102, the portion surrounded by the dam bar 110 is thermoset. The resin is sealed with a sealing resin such as a resin. During this resin encapsulation, if the leads are sandwiched between the upper die and the lower die that make up the resin encapsulating mold, and if the gap between the leads is not filled with anything, the gap between the leads is sealed. Stop resin leaks. Therefore, the dam bar 110 is provided at the boundary between the outer lead and the inner lead to prevent the sealing resin from leaking from the gap between the leads. By the way, conventionally, the lead frame 100 is formed by press working from a metal plate.
20 is also formed integrally with the lead. Therefore, in the semiconductor device that has passed the resin sealing step, the dam bar 110 is cut in order to insulate the adjacent leads.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
By providing 0, the semiconductor device finally obtained can exhibit a good appearance without the sealing resin leaking out. However, the conventional lead frame 100 shown in FIG. 5 requires a cutting step of cutting the dam bar 110 after the resin sealing is completed, which complicates the manufacturing process of the semiconductor device. Such dam bar 110
In order to eliminate the need for the cutting step, the resin film is pressure-bonded to the upper and lower sides of the leads (hereinafter, sometimes referred to as leads) at the boundary forming the dam bar 110, and the resin film is filled between the leads by pressing from above and below. Or a method of applying a thermosetting resin liquid to a predetermined portion and curing it to form a dam bar has been studied. According to such a plastic dam bar, although the cutting step of the dam bar can be omitted, there is a gap due to insufficient filling of the resin film between the leads or a gap due to bubbles in the thermosetting resin liquid. , May be formed in the resin filling the space between the leads. The gap between the leads may cause the sealing resin to leak and impair the appearance of the semiconductor device. Therefore,
An object of the present invention is to provide a lead frame having a dam bar, which can sufficiently seal between the leads held in a resin sealing mold during resin sealing, and can omit the dam bar cutting step after resin sealing, Another object of the present invention is to provide a method of manufacturing a semiconductor device using the lead frame.

[0004]

DISCLOSURE OF THE INVENTION As a result of studies to achieve the above object, the inventors of the present invention have found that a narrow resin member made of a thermoplastic resin and made of a thermoplastic resin, in which a groove for receiving a lead is formed, is formed. By using it as a dam bar, the narrow resin member is softened due to the heat during resin sealing, the gap between the leads is sufficiently filled with resin, and the dam bar cutting process after resin sealing is omitted. Find out what you can do,
The present invention has been reached. That is, the present invention is a lead frame in which a dam bar is provided at the boundary between the inner lead and the outer lead, and as the dam bar, a narrow member having a plurality of recessed grooves for inserting the leads of the boundary is formed. In the lead frame, which is used and at least the inner wall surface of the concave groove of the narrow member which is in contact with the lead is formed of a thermoplastic resin. Further, the present invention uses the narrow width member as a dam bar as a lead frame when a semiconductor device is manufactured by resin-sealing a lead frame to which a mounted semiconductor chip and a tip portion of an inner lead are bonded. Using the same lead frame, the thermoplastic resin forming the inner wall surface of the groove of the dam bar is softened by the heat of the sealing resin or the like filled in the mold for resin sealing, and the lead and the dam bar are integrated. And a method of manufacturing a semiconductor device.

In the present invention having such a structure, forming the dam bar from a thermoplastic resin allows the dam bar to be easily molded by melt molding. Further, since the dam bar is formed of the thermoplastic resin that softens at the resin sealing temperature of the lead frame, the gap between the leads can be sufficiently filled with the thermoplastic resin forming the dam bar.

[0006]

According to the present invention, since the inner wall surface forming the concave groove of the dam bar is formed of the thermoplastic resin, the heat softened by the heat added to the melting of the sealing resin at the time of resin sealing is applied. The plastic resin is deformed by the pressure applied from the mold or the like, and the thermoplastic resin can be filled between the leads without any gap. Therefore, the sealing resin can be prevented from leaking from between the leads, and a semiconductor device having a good appearance can be obtained. Further, the electrical insulation between the leads is also made of the filled thermoplastic resin, and the step of cutting the dam bar can be omitted for the semiconductor device that has passed the resin sealing step.

[0007]

The present invention will be described in more detail with reference to the drawings.
FIG. 1 shows a state in which the dam bar 10 is attached to the leads 12, 12 ... This dam bar 10 is the dam bar 1 of the lead frame 100 shown in FIG.
It is installed at the same position as 10. Dam bar 1 shown in FIG.
Reference numeral 0 is a narrow member made of a thermoplastic resin, and as shown in FIG. 2, the groove 1 into which the leads 12, 12, ... Are inserted.
4 are formed in the width direction of the dam bar 10. Therefore, the leads 12, 1 are inserted in the concave grooves 14, 14 ,.
2 ... When inserted, the inter-groove portion 16 between the recess grooves 14,
16 ... Are inserted in the gap between the leads 12. The thermoplastic resin forming the dam bar 10 is a resin that softens at the resin sealing temperature, and resins such as polyethylene terephthalate, nylon, polycarbonate, and polyoxymethylene can be used. In particular, by adopting a thermoplastic resin that can be injection-molded, the dam bar 10 can be easily molded by injection molding.

In the present embodiment, the recessed grooves 14, 14 ... Formed in the dam bar 10 have the leads 1 as shown in FIG.
It may be formed wider than the lead 12 in order to facilitate insertion of the wires 12, 12. If the groove 14 is formed wider than the lead 12 and the dam bar 10 mounted on the lead frame is likely to fall off, an adhesive or the like is applied to a part of the groove 14 to temporarily bond the lead 12. Good.
Further, as shown in FIG. 3, after inserting the lead 12 into the groove 14 of the dam bar 10, a narrow film 18 made of a thermoplastic resin may be placed on the lead 12. In this case also, in order to prevent the film 18 from falling off, the film 18 may be temporarily adhered with an adhesive or the like.

A semiconductor chip is mounted on the stage in the lead frame in which the leads are inserted into the recessed grooves 14 of the dam bar 10 in this manner, and the electrodes of the mounted semiconductor chip and the tips of the inner leads are wire-bonded. After that, it is inserted into a mold for resin sealing. At this time, the semiconductor chip or the like is inserted into the cavity of the resin-sealing die, and at least a part of the dam bar 10 is held between the upper die and the lower die that form the resin-sealing die. Then, a thermosetting resin is filled as a sealing resin in the resin-sealing mold, and the thermoplastic resin forming the dam bar 10 is heated and softened by the heat of the sealing resin and the like. The dam bar 10 is deformed by the mold closing force of the mold and the lower mold, and the dam bar 10 and the lead 12 are integrated. At this time, even if there is a gap between the inner wall surface of the concave groove 14 of the dam bar 10 and the outer surface of the lead 12, it is blocked by the thermoplastic resin, so that the gap between the leads 12 is separated by the thermoplastic resin. It is filled without. In the present embodiment, the lead 12 is inserted into each groove 14 of the dam bar 10 by mounting the dam bar 10 in a predetermined position of the upper mold or the lower mold of the sealing resin mold in advance. Alternatively, the frame may be placed on the lower mold at a predetermined position and then the upper mold and the lower mold may be closed.

The dam bar 10 shown in FIGS. 2 and 3 is formed of a thermoplastic resin, but as shown in FIG. 4, a concave groove 34 for inserting the lead 12 into a narrow metal member is formed. The formed dam bar 30 may be used.
The metal dam bar 30 can improve the strength of the dam bar as compared with the dam bar 10 formed of a thermoplastic resin. When such a metal dam bar 30 is used, as shown in FIG. 4, the inner wall surface of the concave groove 34 into which the lead 12 formed in the dam bar 30 is inserted is formed by a film 32 made of a thermoplastic resin. The film 32 can insulate the lead 12 and the dam bar 30 from each other, and the film 3 can be formed at the time of resin sealing.
The deformation of 2 can eliminate the gap between the lead 12 and the concave groove 34. In the lead frame of the present embodiment, the place where the dam bar is formed is usually a portion where the gap between the leads is usually standardized. Therefore, as in the present embodiment, a groove for inserting the lead 12 in advance is formed. Even when the narrow member formed with is formed as a dam bar, it is possible to substantially meet the demand by holding several types of dam bars having different groove intervals.

[0011]

According to the present invention, the dam bar cutting step of cutting the dam bar after resin sealing can be omitted, and the steps of the semiconductor device can be simplified. In addition, since it is possible to easily and sufficiently fill the space between the leads at the boundary between the inner lead and the outer lead, a semiconductor device having a good appearance can be obtained.

[Brief description of drawings]

FIG. 1 is a partial perspective view showing a part of a dam bar according to the present invention.

FIG. 2 is a partial cross-sectional view showing a state in which a lead is inserted in the groove of the dam bar.

FIG. 3 is a partial sectional view showing another embodiment according to the present invention.

FIG. 4 is a partial sectional view showing another embodiment according to the present invention.

FIG. 5 shows a front view of a conventional lead frame.

[Explanation of symbols]

 10, 30 Dam bar 12 Lead 14, 34 Recessed groove 16, 36 Between recessed grooves

Claims (6)

[Claims] 1. A lead frame in which a dam bar is provided at a boundary between an inner lead and an outer lead, wherein the dam bar is a narrow member having a plurality of recessed grooves into which the leads of the boundary are inserted. The lead frame is characterized in that at least the inner wall surface of the narrow groove of the narrow member that is in contact with the lead is formed of a thermoplastic resin. 2. The lead frame according to claim 1, wherein the dam bar is made of a thermoplastic resin. 3. The lead frame according to claim 1, wherein the thermoplastic resin is softened without melting at the resin sealing temperature of the lead frame. 4. A lead frame according to claim 1, which is used as a lead frame when a semiconductor device is manufactured by resin-sealing a lead frame to which a mounted semiconductor chip and a tip of an inner lead are bonded. Then, the thermoplastic resin forming the inner wall surface of the recessed groove of the dam bar is softened by the heat of the sealing resin or the like filled in the resin sealing mold, and the lead and the dam bar are integrated with each other. Device manufacturing method. 5. The method of manufacturing a semiconductor device according to claim 4, wherein the dam bar is made of a thermoplastic resin. 6. The method of manufacturing a semiconductor device according to claim 4, wherein the thermoplastic resin is softened at a resin sealing temperature of the lead frame.