JPH0493057A - Manufacture of electronic parts lead frame and electronic parts using the same - Google Patents

Abstract

PURPOSE:To prevent burr of a resin sealing structure from being produced and prevent a blanking blade upon cutting away leads from being worn by extending one edge of a coupling part connecting and supporting a plurality of leads along a resin sealing boundary line, and providing in the coupling part a predetermined width etching groove extending an extension line of opposite edges of each lead and terminating in the coupling part. CONSTITUTION:Upon sealing a semiconductor chip and the like with resin by holding a lead frame between upper and lower surfaces 16, 17, the resin is first pressed into a space C. Thereupon, the resin is dammed by one edge 13a of a coupling part 13, and is prevented from flowing out between the leads 12, 12. For the coupling part 13, in a process where the leads 12 are cut away each other for a needed bending processing one edge D1 of a blanking blade D is disposed at a location spaced a predetermined distance from a resin sealing boundary line X, and opposite side edges D2, D3 are disposed so as to lower into an etching groove 13b, and further upon cutting down part of the etching groove 13b is torn out.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a lead frame or a large number of leads used in resin mold-sealed semiconductor devices such as ICs, LSIs, power transistors, and small signal transistors. Regarding lead frames used in resin mold-sealed connectors that extend outside, especially during resin molding, it is necessary to dam up the resin so that it does not flow out of the mold through the gaps, and prevent the occurrence of paris. The present invention relates to improvements in lead frames that can be prevented.

(Prior Art) An example of a conventional glue frame for semiconductor devices is shown in FIG. This lead frame] O supports an island 1 for attaching a semiconductor chip, a plurality of glue parts 2 for connecting bonding wires, a dam bar 3 that interconnects these parts while the lead 2 is being extended, and the leads 2. It is provided with a frame part 4. The lead 2 extends from the frame 4 toward the island, and its tip is close to the island 1.

In this lead frame 10, a semiconductor chip (not shown) is mounted on the island 1 and wire bonded, and then the inside of the resin sealing boundary line X shown in FIG. 4 is sealed by resin molding. This resin molding is performed, for example, by sandwiching the frame 10 between the upper and lower molds 6 and 7 and press-fitting the resin into the space C, as shown in FIG. At this time, the resin overflows into the gap between each lead 2.2, so this is stopped by a dam bar 3. However, the dam bar 3 is provided at a position a predetermined distance away from the boundary line X.

This is because, although this dam bar 3 will be cut out later to separate each lead 2, in this cutting process, sufficient spacing is required to prevent the cutting teeth from contacting and damaging the resin sealing body 5. This is because it is necessary to set the Therefore,
A gap S is formed between each of the boards 2 on the tip side of the dam bar 3, and formation of a gap 5a (FIG. 5) inside this gap is unavoidable. A part of this paris 5a is later cut off with a punching blade together with the dam bar 3, but high hardness particles may be mixed into the sealing resin, and in such a case, the punching blade is cut off. Promotes blade wear.

In order to eliminate the occurrence of this gap 5a, a piece 7a for filling the gap S is also implanted in the molding die 7, as shown in FIGS. 6 and 7. However, such molds are not easy to manufacture because they require high precision, are expensive, and are prone to wear.
Cannot withstand long-term use. Further, a slight gap inevitably forms in the gap around the frame 7a. Therefore, in any case, a step of removing paris by shot 1, blasting, etc. is required afterwards. Further, as the number of leads 2 increases and the size of the circuit becomes smaller as the circuit becomes more integrated, it becomes impossible to miniaturize the piece 7a accordingly.

The same situation applies to resin-molded connectors in which a large number of leads extend outside the resin-sealed body.

(Problems to be Solved by the Invention) Therefore, the present invention prevents the occurrence of burr on a resin-sealed body without using an expensive mold, thereby completely omitting the subsequent burr removal step, Another object of the present invention is to provide a lead frame that can suppress wear of a punching blade when cutting out each lead, and a method of manufacturing a semiconductor device using the lead frame.

(Means for Solving the Problems) In the present invention, in order to solve the above problems, one edge 13a of the connecting part 13 that connects and supports the plurality of glue parts 12 is connected to the boundary of the resin sealing body 15. Bring it to the nearest line X,
The connecting portion 13 is provided with an etching groove 1.3b of a predetermined width extending along the extension line of both edges of each lead 2 and terminating within the connecting portion 13. After the resin sealing process, the connecting portion 13 is cut out using a punching blade. At this time, the edges D2 and D3 on both sides of the punching blade are arranged so as to descend into the etching groove 13b,
The other edge D1 was disposed so as to fall at a predetermined minute distance from the resin sealing boundary line X, and at the time of cutting, a part of the etching groove 13b was torn off.

(Function) The lead frame 20 of the present invention has upper and lower molds 1.6.
．． When sealing a semiconductor chip or the like with resin between 17 and 17, since one side g13a of connecting part 13 is along the resin sealing boundary line X, the resin overflows between -1 and 12. to prevent

A small amount of resin enters into the etching groove 13b, but the amount is extremely small. In any case, the sealing resin does not bulge between -1 and -12.

Therefore, a subsequent deburring step is not necessary. Connecting part 1
3 is punched out using a blade to separate the leads 12 from each other. At this time, slightly etching groove 1
The resin that has entered into 3b is also scraped off. The punching blade passes through a position away from the side surface of the resin sealing body 15. Therefore, a portion of the etching groove 13b near the resin sealing boundary line X is bowed, but this portion is thin and does not interfere with the cutting of the connecting portion 13. Further, in the cutting process of the connecting portion 13, there is no risk that the punching blade will come into contact with the resin sealing body 15 and cause damage, and the punching blade itself will not be damaged.

(Example) An embodiment of the present invention is shown in FIGS. 1 to 4.

Fig. 1 is a plan view of a part of the lead frame, Fig. 2 is a perspective view of a part of the lead frame, and Fig. 3 is a sectional view taken along the ni-nt line in Fig. 1 during the molding process of the sealing resin. , Fig. 4(A) is a plan view of a part of the lead frame after resin sealing and before the connecting part is removed, and Fig. 4(B) is a plan view of a part of the lead frame after the connecting part is removed. FIG.

In FIGS. 1 to 4, the lead frame 20 is
Island 1 for mounting a semiconductor chip (not shown)
1, a plurality of glue portions 12 provided around the island 11, and a connecting portion 13 that connects these leads 12 to each other.

The reels l to 12 extend from the frame portion 14 toward the island 1, and one end is close to the island 1.

A bonding wire (not shown) is later connected between one end of the lead 12 and the semiconductor chip.

The leads 12 are interconnected by connecting portions 13 in the middle of their extension. One edge 13a of the connecting portion 13
extends along the immediate vicinity of the boundary line X of the resin sealing body 15. Further, the connecting portion 13 is provided with an etching groove 13b having a predetermined width that enters from one edge 13a along an extension line of both edges of the portion 12 and terminates within the connecting portion 13. The thickness of the connecting part J3 is usually about 0.15 mm, and it is etched! A\] - Approximately 0.075mm within 3b
It is. Further, the width of the etching groove 13b is usually about 0.
．． 05~O, ]mm.

Therefore, this lead frame 20 has an island 11
After mounting a semiconductor chip (not shown) thereon and performing wire bonding, resin is molded within the resin sealing boundary line X shown in FIG. 1 to seal it. This resin molding is performed, for example, by sandwiching the lead frame 20 between upper and lower molds 16 and 17 and press-fitting the resin into the space C, as shown in FIG. At this time, the resin is
It is dammed by one edge 13a of the connecting portion 13, and is prevented from flowing out between the leads 2, 2.

The connecting portion 13 is punched out using a cutting edge having a rectangular cross section as shown in phantom lines in FIG. One edge D1- of the punching blade is at a predetermined distance (for example, 0.05 mm-0.1
mm) so as to descend at a distance, and the edges D2 on both sides.
D3 are arranged so as to descend into the etching grooves 13b. Therefore, in the punching process, the etching groove 1
There is no blade between one edge D1 of the blade and one edge 13a of the connecting portion 13 in 3b, and this portion is torn off. However, since this portion has a wall thickness of approximately 0.075 mm, it does not interfere with punching. The position of the punching blade is on the edge D1
is near the resin sealing boundary line X, and both side edges D2. Since D3 can easily descend into the etching grooves 13b, it is not necessary to control with high precision. In addition, since the punching blade descends at a position away from the resin sealing boundary line X, there is a risk that the resin sealing body 15 may be scraped and damaged in the cutting process of the connecting portion 13, or the resin sealing body 15 may be damaged. There is no.

Although the case where the present invention is applied to a lead frame for a semiconductor device has been described above, the present invention is not limited to this. In short, the present invention can be applied to lead frames for all other electronic components, such as connectors in which a large number of glues -1- extend outside the resin sealing body.

(Effects of the Invention) As described above, in the present invention, one edge 1.3a of the connecting portion 13 that connects and supports the plurality of glue portions 12
is brought close to the boundary line X of the resin sealing body 15, and the connecting portion 13 is extended along the extension line of both edges of each lead 12.
Etching groove 13b with a predetermined width that terminates within the connecting portion 13
has been established. After the resin sealing process, the connecting portion 13 is cut out using a punching blade.

At that time, edges D2 on both sides of the punching blade. D3 is disposed so as to descend into the etching groove 13b, and the other edge D1 is disposed so as to descend at a predetermined minute distance from the resin sealing boundary line X. When cutting, the etching groove 13b is Since a portion is torn off, one edge 13a of the connecting portion 13 prevents the resin from flowing out between the leads 12 during the resin sealing process, thereby preventing the occurrence of burrs on the resin sealing body 5. be able to. Therefore, there is no need to use a precise and expensive mold, and the process of removing paris can be completely omitted. Since the punching blade used to cut off each lead 12 does not come into contact with the resin sealing body 15, it has little wear and can withstand long-term use. Therefore, the manufacturing cost of electronic components such as semiconductor devices can be significantly reduced.

[Brief explanation of drawings]

1 to 4 show an embodiment of the present invention,
FIG. 1 is a plan view of a portion of the lead frame, FIG. 2 is a perspective view of a portion of the lead frame, and FIG. 3 is a sectional view taken along the line m-nr in FIG. 1 during the molding process of the sealing resin. FIG. 4(A) is a plan view of a portion of the lead frame after resin sealing and before the connecting portion is removed, and FIG. 4(B) is a plan view of a portion of the lead frame after the connecting portion is removed. 5 to 7 show conventional examples, in which FIG. 5 is a plan view of a lead frame for a semiconductor device, and FIG. 6 is a diagram showing a process of molding a sealing resin. 7 is a sectional view showing another example of the molding die, and FIG. 8 is a sectional view taken along line 7--1. ] 1... Island 12... Lead 13... Connection portion 13a... Edge 13b... Etching groove 15... Resin sealing body 20... Lead frame D... Punching blade Dl ...Edge D2...Edge D3...Edge X...Resin sealing boundary line Figure 4 (A) Figure 4 (B)

Claims (3)

[Claims] (1) In a device having a plurality of leads whose one ends are resin-sealed and a connecting portion connecting these leads to each other outside the resin-sealing portion, one edge of the connecting portion is connected to the resin-sealing boundary. An electronic device characterized in that the connecting portion is provided with an etching groove of a predetermined width that extends along the immediate vicinity of the boundary line and extends along the extension line of both edges of each lead and terminates within the connecting portion. Lead frame for parts. (2) The above-mentioned device having an island for mounting a semiconductor chip, a plurality of leads for connecting bonding wires whose ends are provided close to the island, and a connecting portion connecting these leads to each other. One edge of the connecting part extends along the immediate vicinity of the resin sealing boundary line, and the connecting part extends along the extension line of both edges of each lead,
A lead frame for electronic components, characterized in that an etched groove of a predetermined width is provided that terminates within a connecting portion. (3) The lead frame for electronic components according to claim (1) or (2) is sandwiched between two upper and lower molds to mold a resin sealing body, and then the connection is performed using a punching blade having a rectangular cross section. In the step of punching out and cutting off the leads to separate the leads from each other, both edges of the punching blade are placed so as to descend into the etching groove, and the other edge is placed at a predetermined distance from the resin sealing boundary line. A method of manufacturing electronic components, characterized in that the electronic components are arranged so as to descend at positions a minute distance apart.