JPH08250640A - Manufacture of lead frame and plastic molded type semiconductor device using the same - Google Patents

Abstract

PURPOSE: To restrain the trouble due to position deviation of a resin molding part which is caused by the cutting of island support, by connecting lead tips which are not resin molded by a linkage part, and connecting the linked lead group with an outer frame by a holding part. CONSTITUTION: A lead frame 1 to be used for assembling a plastic molded type semiconductor device has the following; an island for mounting a semiconductor element, a plurality of leads 3 arranged around the island 2, and an outer frame 4 holding the island 2 and the leads 3. The tips of a plurality of the leads 3 constituting a lead group which tips are not resin molded are connected by a linkage part 6. The connected leads 3 are further connected with the outer frame 4 by a holding part 7. In the case of carriage to a metal mold for bending the leads 3, the carriage is performed in the state held on the outer frame by the holding part 7, so that the trouble caused by the cutting of island support can be restrained, and metal mold breakdown and product breakdown can be prevented.

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 resin-encapsulated semiconductor device using the same, and more particularly to a lead frame for preventing troubles during bending of external leads after resin encapsulation and the use thereof. The present invention relates to a method for manufacturing a resin-sealed semiconductor device.

[0002]

2. Description of the Related Art In a final step of assembling a resin-sealed semiconductor device, a lead frame is resin-sealed by a molding machine,
There is a step of bending the lead portion led out from the resin sealing portion to form the final product shape. Generally, a lead frame 20 as shown in FIG. 6 is used for assembling a resin-sealed semiconductor device. The lead frame 20 includes an island 21 on which a semiconductor element is mounted, and a plurality of leads 22 arranged around the island 21. The island 21 is held by an outer frame 24 by an island support 23, and the leads 22 are kept outside. It is directly connected to the frame 24.

Bending of a resin-sealed semiconductor device using the lead frame 20 is performed by the method shown in FIGS. The method shown in FIG.
After resin-sealing, the leads 22 led out from the outer frame 24 and the resin-sealing portion 25 are cut, and the resin-sealing portion 25 is held on the outer frame 24 by the island support 23, and the lead frame 20 is used as a unit. Transfer to a bending mold. And FIG.
As shown in (b), the lead 22 led out from the resin sealing portion 25 is processed into a predetermined shape by a bending die (not shown). Finally, the island support 23 is cut to complete a resin-molded semiconductor device having a predetermined lead shape.

Further, in the method shown in FIG. 8A, the leads and the island support are cut from the outer frame of the lead frame which has been resin-sealed, and the resin-sealed portion 25 and the lead frame are separated from each other. It is conveyed as a single item to the bending die. Then, as shown in FIG. 8B, the resin sealing portion 25
The lead 22 derived from the above is processed into a predetermined shape by a bending die (not shown) to complete a resin-sealed semiconductor device having a predetermined lead shape.

In the method shown in FIG. 9, the lead frame 20 is resin-sealed, and then the resin-sealed portion 25 is held by the leads 22 on the outer frame 24 and conveyed to a bending die.
As shown in (b), the leads 22 led out from the resin encapsulation portion 25 are processed into a predetermined shape by a bending die (not shown) to complete a resin encapsulation type semiconductor device having a predetermined lead shape.

[0006]

However, the above-mentioned method may cause the following problems. In the method shown in FIG. 7, only the island support 23 is used for the resin sealing portion 2.
Since 5 is held in the outer frame 24, the island support 23 may be cut during the transportation to the bending die, and the die may be damaged or the product itself may be destroyed. In particular, when the notch 26 for preventing the resin sealing portion 25 from being chipped when the island support 23 is cut is provided in the corner portion, the island support 23 becomes weak and is often cut.

Further, in the method shown in FIG. 8, the leads and the island supports are cut from the outer frame of the lead frame, conveyed to a bending die in the state of a single product before processing, and led out from the resin sealing portion 25. Since the lead 22 is processed,
There is a problem that the productivity is low as compared with the above-described method of carrying in lead frame units. Further, in the method shown in FIG. 9, since the lead 22 is cut and bent at the same time, the lead 22 is molded while scraping the plating, and the scraped plating adheres between the leads 22 to cause a short circuit. It was also accompanied.

In view of the above-mentioned problems, the present invention provides a lead frame capable of holding the resin encapsulation portion more firmly and having high productivity, and a method of manufacturing a resin encapsulation type semiconductor device using the same. Is.

[0009]

The present invention has the following constitution in order to achieve the above object. That is, the lead frame of the present invention is for a resin-sealed semiconductor device having an island on which a semiconductor element is mounted, a plurality of leads arranged around the island, and an outer frame holding the island and the lead. In the lead frame,
It is characterized in that it has a connecting portion for connecting the leading end portion of the lead that is not resin-sealed, and a holding portion for holding the lead and the outer frame connected by the connecting portion.

A method of manufacturing a resin-sealed semiconductor device according to the present invention, which can suitably implement the above lead frame, comprises:
The step of fixing the semiconductor element to the lead frame according to claim 1, the step of wire bonding the bonding pad of the semiconductor element and the corresponding lead with a metal wire, and the step of resin-sealing a predetermined portion of the lead frame. And a step of molding the lead after the above steps while the resin sealing portion is held by the holding portion on the outer frame of the lead frame.

[0011]

The lead frame of the present invention has a connecting portion for connecting the tip portions of the leads which are not resin-sealed, and the connected lead group and the outer frame are connected by the holding portion. It is possible to prevent problems due to positional displacement of the resin sealing portion due to breakage of the island support that occurred during the transportation of the lead molding process, and prevent problems such as mold damage and product destruction.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG. The lead frame 1 of the present invention used for assembling a resin-sealed semiconductor device has an island 2 on which a semiconductor element is mounted, for example, by punching or chemically treating a thin plate of iron-nickel alloy (42 alloy) or copper alloy. And a plurality of leads 3 arranged around the island 2 and an outer frame 4 for holding the island 2 and the leads 3,
The island 2 is connected to the outer frame 4 by an island support 5. The plurality of leads 3 arranged around the island 2 extend in a direction substantially perpendicular to each side of the island 2. The leads 3 extending on each side of the island 2 form a lead group on each side. The ends of the plurality of leads 3 forming the lead group, which are not resin-sealed, are connected by a connecting portion 6. The plurality of leads 3 connected by the connecting portion 6 are further connected to the outer frame 4 by the holding portion 7.

A method of manufacturing a resin-sealed semiconductor device using the above lead frame 1 will be described with reference to FIGS. First, as shown in FIG. 2A, after mounting the semiconductor element 8 on the island 2, the bonding pad of the semiconductor element 8 and the corresponding tip of the lead 3 are wire-bonded by the Au wire 9. Then, FIG.
As shown in (b), the lead frame 1 on which the semiconductor element 8 is mounted and wire bonding is performed in a resin sealing step,
Resin sealing portion 10 covering the island 2 and a part of the lead 3
To form. Notches 11 are provided at the respective corners of the resin sealing portion 10 to facilitate the cutting of the island support 5.

Next, as shown in FIG. 3 (c), after the resin sealing step is completed, in the next lead forming step, the outer frame 4 is first formed.
The island support 5 is cut from the lead, and the lead group derived from each side of the resin-sealed portion 10 is connected to the tip portion of the lead 3 by the connecting portion 6. It is conveyed to the bending mold of No. 3. Conventionally, the transportation is carried out while being held by the island support 5, but in the present invention, since it is carried while being held by the outer frame 4 by the holding portion 7 connected to the lead group, troubles due to the island support being cut off may occur. Can be suppressed, and problems such as mold damage and product destruction can be prevented. In the bending die, the lead 3 and the holding portion 7 are simultaneously bent.

Finally, as shown in FIG. 3D, the lead 3 is separated by cutting a predetermined position of the connecting portion 6 connecting the leads 3 to each other, and the holding portion 7 is cut from the outer frame 4. ,
A resin-sealed semiconductor device having a predetermined lead shape is completed.
Next, another embodiment of the lead frame used in the present invention will be described. The lead frame shown in FIGS. 4 and 5 shows the positional relationship and shape of the lead 3, the connecting portion 6, the holding portion 7 and the outer frame 4 which are led out from one side where the resin sealing portion 10 is present.

The holding portion 7 of the lead frame shown in FIGS. 4A, 4B and 4C has a crank shape and connects the outer frame 4 to the leads 3 and the connecting portion 6. Particularly, in the shape shown in (c), four holding portions 7 are connected. By making the holding portion 7 have the above-described shape, the holding portion 7 is less likely to be deformed when performing burr treatment, lead plating, or the like.

The holding portion 7 of the lead frame shown in FIGS. 5A and 5B has a substantially U-shaped bent portion 12 between the connecting portion 6 and the outer frame 4. In addition, since the holding portion 7 has a shape that is easily bent by forming the holding portion 7 in the above-described shape, stress during molding of the lead 3 can be relieved.

[0018]

As described above, according to the present invention, the connecting portion for connecting the tip portions of the leads which are not resin-sealed,
Since the connected lead group and the outer frame are connected by the holding part, there is no problem due to misalignment of the resin sealing part due to island support breakage that occurred during the lead molding process after resin sealing. It can be suppressed and problems such as mold damage and product destruction can be prevented.

[Brief description of drawings]

FIG. 1 is a perspective view showing a lead frame of the present invention.

FIG. 2 is a perspective view showing a bending method of the present invention.

FIG. 3 is a perspective view showing a bending method of the present invention.

FIG. 4 is an explanatory diagram showing another lead frame of the present invention.

FIG. 5 is an explanatory diagram showing another lead frame of the present invention.

FIG. 6 is a perspective view showing a conventional lead frame.

FIG. 7 is a perspective view showing a conventional bending method.

FIG. 8 is a perspective view showing a conventional bending method.

FIG. 9 is a perspective view showing a conventional bending method.

[Explanation of symbols]

 1 lead frame 2 island 3 lead 4 outer frame 5 island support 6 connecting part 7 holding part 10 resin sealing part

Claims (2)

[Claims] 1. A lead frame for a resin-sealed semiconductor device, comprising: an island on which a semiconductor element is mounted; a plurality of leads arranged around the island; and an outer frame for holding the island and the lead. A lead frame, comprising: a connecting portion for connecting a tip end portion of the lead, which is not resin-sealed, and a holding portion for holding the lead and the outer frame connected by the connecting portion. 2. A step of fixing a semiconductor element to the lead frame according to claim 1, a step of wire-bonding a bonding pad of the semiconductor element and a lead corresponding thereto with a metal wire, and a predetermined portion of the lead frame. A method of manufacturing a resin-encapsulated semiconductor device, comprising: a step of resin-sealing; and a step of molding a lead after the step with the resin-sealing portion being held by an outer frame of a lead frame by a holding portion.