JPH0714965A - Lead frame for semiconductor device - Google Patents

Abstract

PURPOSE:To provide a lead frame for a semiconductor device that does not need burr removal operation in the air bend part of a mold die, and that further can prevent the generation of a fill-up fail of resin due to close-packing with burr in the air bend part of the mold die. CONSTITUTION:In a lead frame 3 for a semiconductor device having a dam 4 formed so as to enclose the resin seal part of a semiconductor device; and a plurality of leads coupled by this dum 4, a deflating groove 15 crossing the dam 4 is provided on a surface of the dam 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame used in a resin-sealed semiconductor device.

[0002]

2. Description of the Related Art Conventionally, this type of resin-encapsulated semiconductor device is generally manufactured as follows. That is,
The resin-sealed semiconductor device is manufactured by mounting a semiconductor element on a lead frame and sealing the lead frame on which the semiconductor element is mounted with a thermosetting resin. In the resin-encapsulated semiconductor device, as shown in FIG. 6, each electrode of the semiconductor element 102 and the lead 103 are not shown in a wire with the semiconductor element 102 placed on the tab 101 of the lead frame 100. Connect by bonding. In addition, the lead frame 100 is
A dam 105 surrounding the resin sealing portion 104 is provided so that the resin does not flow out of the resin sealing portion 104 when the resin is injected. Then, at the time of resin sealing, the lead frame 100 to which the semiconductor element 102 is attached is placed inside the lower mold die 106 as shown in FIG. It is clamped by the upper mold die 107.

In this way, as shown in FIG. 7, the lead frame 100 to which the semiconductor element 102 is attached is sandwiched by the upper and lower mold dies 106 and 107, and the lead frame 100 is attached to the upper mold dies 107. A thermosetting resin 110 for sealing is injected and filled into a cavity 111 formed between the upper and lower mold dies 106 and 107 via a runner portion 108 and a gate portion 109 formed so as to cross the dam 105. At the same time, the air in the cavity 111 is removed from the air bend portion 112 provided in the upper molding die 107 to the outside to perform air bleeding.

Next, after the resin has hardened, the upper and lower molding dies 106 and 107 are opened, and the resin 110 of the runner portion 108, the gate portion 109 and the cavity portion 111 integrated with the lead frame 100 is molded. 106, 1
Take out from 07. And finally unnecessary runner part 1
The resin 110 cured by 08 or the gate portion 109 is mechanically removed from the surface of the lead frame 100 to form the resin sealing portion 104 of the semiconductor device as shown in FIG.

[0005]

However, the above-mentioned prior art has the following problems. That is, in the conventional resin-encapsulated semiconductor device described above, resin encapsulation is performed with the lead frame 100 sandwiched between the upper and lower molding dies 106 and 107. An air bend portion 112 for bleeding air is provided. Therefore, as shown in FIG. 7, a thermosetting resin 110 for sealing is formed between the upper and lower mold dies 106 and 107 via the runner portion 108 and the gate portion 109 formed on the upper mold die 107. When injecting and filling the inside of the cavity 111,
The resin 110 enters the air bend portion 112 and hardens, and remains as a resin burr on the upper molding die 107. Therefore, conventionally, it is necessary to remove the burrs of the cured resin in the air bend portion 112 by brushing and air-blowing the bonding surfaces of the upper and lower mold dies 106 and 107 each time after resin sealing. There was a problem that was complicated.

Further, since the width and depth of the air bend portion 112 of the upper mold die 107 are set to be small, it is difficult to remove the resin burr hardened by the air bend portion 112, and the air bend portion is difficult to remove. The cured resin may remain in 112. Therefore, when injecting the resin 110 into the cavities 111 of the upper and lower molds 106 and 107 next time, air is not sufficiently exhausted from the air bend portion 112, and there is a problem that injection failure of the resin 110 occurs.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The object of the present invention is to eliminate the need to remove the burrs from the air bend portion of the mold. It is an object of the present invention to provide a lead frame for a semiconductor device, which can prevent defective filling of resin due to clogging of a mold air bend portion.

[0008]

That is, the present invention is
In a lead frame for a semiconductor device having a dam formed so as to surround a resin-sealed portion of a semiconductor device and a plurality of leads connected by this dam, for removing air so as to cross the dam on the surface of the dam. The groove portion is provided.

The air vent groove is provided, for example, on the surface of the dam, but the air vent groove may be provided on both front and back surfaces of the dam.

The air vent groove is, for example,
Although only one place is provided on the surface of the dam, this air vent groove may be provided at each of the four corners of the dam.

[0011]

According to the present invention, since the air vent groove is provided on the surface of the dam so as to traverse the dam, a pair of molds are held in a state where the lead frame is sandwiched by a pair of mold dies. When injecting and filling resin into the cavity formed between the molds to form the resin sealing portion, the air in the cavity is passed through the air vent groove provided on the surface of the dam so as to cross the dam. Can be removed. Therefore, since it is not necessary to provide the air bend portion in the pair of molds, it is not necessary to remove the burrs from the air bend portion, and further, the resin filling failure due to the clogging of the air bend portion of the mold die may occur. Can be prevented.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments.

FIG. 1 shows an embodiment of a lead frame for a semiconductor device according to the present invention.

In FIG. 1, reference numeral 1 denotes a semiconductor device to be manufactured. The semiconductor device 1 includes a semiconductor element 2
The lead frame 3 to which is attached is sealed with a thermosetting resin. In the lead frame 3, a plurality of frames 3 each having a shape corresponding to the semiconductor device 1 are continuously arranged in a strip shape so that the plurality of semiconductor devices 1 can be manufactured by a series of manufacturing steps. As shown in FIG. 1, the lead frame 3 has dams 4 and 4 on both sides thereof, and narrow dams 5 and 5 arranged to connect the dams 4 and 4 to each other. The region surrounded by the dams 4 and 4 and the dams 5 and 5 is the resin sealing portion 6 of the semiconductor device. Further, a tab 7 having a square shape in a plane is arranged in the central portion of the lead frame 3, and the semiconductor element 2 is mounted on the tab 7. The semiconductor element 2 mounted on the tabs 7 of the lead frame 3 has leads 8 whose electrodes extend to the periphery of the tabs 7 of the lead frame 3.
Are connected to each other by wire bonding (not shown).

As described above, the lead frame 3 to which the semiconductor element 2 is attached is sandwiched between the lower mold die 9 and the upper mold die 10 as shown in FIG.
Resin sealing is performed. The lower mold die 9 and the upper mold die 10 are joined to each other with the lead frame 3 sandwiched therebetween, and a cavity corresponding to the resin sealing portion 6 of the semiconductor device 1 is provided between both mold dies 9 and 10. 11 is formed. Further, the upper mold die 10
A runner portion 12 and a gate portion 13 for injecting the resin 14 into the cavity 11 are formed so as to extend over the dam 4 of the lead frame 3.

By the way, in this embodiment, the upper and lower mold dies 9 and 10 are not provided with air bend portions for venting air at the time of resin injection. Instead, air venting is performed on the lead frame 3 side. To form a groove portion for.

That is, the dam 4 of the lead frame 3
As shown in FIG. 1, a groove portion 15 for venting air is formed at a position corresponding to the opposite side of the runner portion 12 of the upper molding die 10 so as to cross the dam 4. As shown in FIG. 3, the groove 15 has a predetermined depth (for example, 0.02 m) in the thickness direction of the lead frame 3.
m) is formed by half etching or pressing over a predetermined width.

With the above-described structure, the lead frame for a semiconductor device according to this embodiment does not require a burr removal work of the air bend portion of the molding die when manufacturing a semiconductor device using this lead frame, Moreover, it is possible to prevent the defective filling of the resin due to the clogging of the air bend of the molding die. That is, as shown in FIG. 2, in the semiconductor device 1, the lead frame 3 to which the semiconductor element 2 is attached at the time of resin encapsulation is placed inside the lower molding die 9 and the lower molding die 9 is formed. It is sandwiched by the upper mold die 10.

As described above, the lead frame 3 to which the semiconductor element 2 is attached is sandwiched between the upper and lower mold dies 9 and 10, and the lead frame 3 is attached to the upper mold 10 as shown in FIG. 1 through the runner portion 12 and the gate portion 13 formed so as to cross the dam 4 of FIG.
And, as shown in FIG. 2, a cavity 11 in which a thermosetting resin 14 for sealing is formed between the upper and lower mold dies 9, 10.
It is injected and filled in.

At the same time, as shown in FIG. 1, the air in the cavity 11 is removed to the outside from the air vent groove 15 formed in the dam 4 of the lead frame 3 to vent the air. . For this reason, the resin 14 filled in the cavity 11 is
In accordance with the air bleeding from the air bleeding groove 15, the entire cavity 11 is completely filled, and a part of the air is emptied into the air bleeding groove 15 of the lead frame 3 to inject the resin 14. Ends.

Next, after the resin 14 has hardened, the upper and lower mold dies 9 and 10 are opened to form the runner portion 12, gate portion 13 and cavity portion 11 integrated with the lead frame 3.
The resin 14 is removed from the molding dies 9 and 10. Finally, unnecessary runner section 12 and gate section 1
The resin 14 cured in 3 is mechanically removed from the surface of the lead frame 3 to form the resin sealing portion 6 of the semiconductor device.

At this time, the cured resin 14 remains in the air vent groove portion 15 of the lead frame 3, but the dam 4 in which the air vent groove portion 15 of the lead frame 3 is formed has a semiconductor device formed by a subsequent process. The cured resin 14 remains in the air vent groove portion 15 of the lead frame 3 because it is removed from the lead frame 3.

As described above, in the lead frame 3 for the semiconductor device according to this embodiment, the dam 4 of the lead frame 3 is used.
Since it is configured to form the groove portion 15 for venting air, it is not necessary to provide air vent portions for venting the upper and lower molding dies 9 and 10. Therefore, when manufacturing the semiconductor device 1 using the lead frame 3, it is not necessary to remove the burrs from the air bends of the molding dies 9 and 10, and moreover, the resin due to the burrs clogging of the air bends of the molding dies 9 and 10. It is possible to prevent the occurrence of defective filling. Further, in the case of continuous resin sealing, the lead frame 3 having the new air vent groove portion 15 is always arranged in the molding dies 9 and 10. Therefore, the resin vent 14 is filled due to clogging of the air vent groove portion 15. No defects occur.

FIG. 4 shows another embodiment of the present invention. The same parts as those of the embodiment of the present invention will be designated by the same reference numerals and will be described. The dam is configured to have air vent grooves on both front and back sides.

As described above, when the dams 4 of the lead frame 3 are provided with the air vent grooves 15 on both the front and back sides, the air of the cavities 11 vertically separated by the lead frame 3 can be evenly vented. Therefore, the balance of the flow of the resin 14 above and below the cavity 11 is improved, and the defective filling of the resin 14 can be reliably prevented. In addition, it is possible to prevent the lead frame 3 from being pressed and deformed by the resin 14.

The other structure and operation are the same as those of the above-mentioned embodiment, and the description thereof will be omitted.

FIG. 5 shows still another embodiment of the present invention. The same parts as those of the embodiment of the present invention will be designated by the same reference numerals. Grooves 1 and 3 for dam 4
5 are provided at the four corners.

As described above, when the air vent grooves 15 are provided on the dams 4 and 5 of the lead frame 3 at the four corners, the air inside the cavity 11 is vented at the corners of the lead frame 3. Therefore, it is possible to reliably prevent the defective filling such as short-circuiting or non-filling of the resin 14 from occurring in the corner of the cavity 11.

The other structure and operation are the same as those of the above-mentioned embodiment, and the explanation thereof will be omitted.

[0030]

EFFECTS OF THE INVENTION The present invention has the above-described structure and operation, does not require the work of removing burrs from the air bend portion of the molding die, and causes defective resin filling due to clogging of burrs in the air bend portion of the molding die. It is possible to provide a lead frame for a semiconductor device, which can prevent the occurrence of damage.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a lead frame for a semiconductor device according to the present invention.

FIG. 2 is a cross-sectional view showing a molding die for manufacturing a semiconductor device.

FIG. 3 is a cross-sectional view showing a groove portion for venting air.

4 (a) and 4 (b) are a fragmentary sectional view showing another embodiment of the semiconductor device lead frame according to the present invention and a sectional view showing a molding die for manufacturing the semiconductor device.

FIG. 5 is a plan view showing still another embodiment of the lead frame for a semiconductor device according to the present invention.

FIG. 6 is a plan view showing a conventional lead frame for a semiconductor device.

FIG. 7 is a cross-sectional view showing a molding die for manufacturing a semiconductor device.

[Explanation of symbols]

3 Lead frame, 4 dam, 15 Air vent groove.

Claims (1)

[Claims] 1. A lead frame for a semiconductor device having a dam formed so as to surround a resin-sealed portion of a semiconductor device and a plurality of leads connected by the dam, the dam crossing the surface of the dam. A lead frame for a semiconductor device, characterized in that a groove portion for venting air is provided.