JPS5915499Y2 - Thin plate connection piece cutting device for resin-sealed semiconductor devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a device for cutting thin plate connecting pieces connecting lead wires drawn out from the device in a resin-sealed semiconductor device.

Punches and dies traditionally used for punching include:
This gives a certain clearance, generally a clearance that is directly proportional to the thickness of the plate being punched.

Therefore, in a semiconductor device A in which a semiconductor element is sealed with resin as shown in FIG. When the connecting piece 2 is cut and the burr 4 generated when sealing the resin coating 3 is removed, the clearance also becomes smaller when the connecting piece 2 is a thin plate.

When cutting such a thin plate connecting piece 2 using a punch and a die, since the clearance provided is small, the components of the punch and die must be processed with high precision and without distortion. Moreover, the assembly and adjustment took a considerable amount of time.

Particularly when the wall thickness of the punch is thin, the distortion due to heat treatment and other processing is large, and if the amount of distortion becomes larger than the clearance value, the punch may hit the die and break. This requires additional processing, such as wrapping.

FIG. 2 shows a slave connecting piece cutting device.

That is, this conventional device consists of a female mold and a male mold 6, and the female mold 5 is formed in a die fixing plate 7 and has a groove 8 in which the resin coating 3 is placed, and a groove 8 in which the resin coating 3 is placed, and a male mold 6. A die 9 is fixed to a fixed plate 7 and has a square hole forming a cutting edge corresponding to the number of connecting pieces 2, and the male die 6 is fixed to the square hole forming the cutting edge of the die 9. It is composed of a punch 10 having an appropriate number of rectangular cutting edges, and a stripper 11 is engaged with each cutting edge of the punch 10.

This conventional cutting device uses a positioning device (not shown) to cut the semiconductor device A shown in FIG.
The resin coating 3 is placed in the groove 8, and each lead wire 1,
a, 1 b, . Each cutting edge and the square hole of the die 9 allow each lead wire 1,1
The connecting piece 2 is cut from a, 1 b, ... and the burr 4 is removed at the same time, but during this cutting and removal operation, the removed burr 4 falls into the groove 8 and remains there. For this reason, the burr 4 left in this groove 8 during the next cutting becomes an obstacle to the resin coating 3 that is subsequently placed, and it is necessary to clean the inside of the groove 8 every time the cutting is performed. This system had the following disadvantages and was extremely inefficient.

This invention aims to provide a cutting device that improves the above-mentioned conventional drawbacks, and one embodiment thereof will be described in detail below with reference to FIGS. 3 to 5.

First, FIGS. 3A and 3B show the basic structure of this invention, and in order to express the gist clearly and concisely, they are examples in which the connecting piece 2 is cut at only one place, In each of these figures and in FIGS. 4 and 5 described below, the same reference numerals as in FIGS. 1 and 2 indicate the same or corresponding parts.

In FIGS. 3A and 3B, the cutting surface 1 of the punch 10
Guide protrusions 12 are provided at the inwardly biased portions of each of 0a.

However, the guide protrusion 12 of the lever has an inclined surface 12a at an angle θ with respect to the cutting edge surface 10a, and this inclined surface 12H prevents the burr 4 from falling into the groove 8 before cutting the connecting piece 2. The burr 4 has a role of guiding the burr 4 into the square hole 9a of the die 9, and its both sides are directed downward from the ridge lines 12b, 12b below the cutting surface 10a. The inclined surfaces 12C, 12C allow the punch 10 to fit into the square hole 9a, which is the cutting edge of the die 9, even if the punch 10 is warped or otherwise distorted. It has the role of guiding people in a way that makes it easier for them to understand.

Therefore, in the basic embodiment of this invention shown in FIGS. 3A and 3B, when the punch 10 is lowered toward the die 9 on which the semiconductor device A is mounted, the punch first protrudes from the punch cutting surface 10a. The lower end of the guide protrusion 12 is inserted into the square hole 9a of the die 9, and while correcting the distortion of the punch 10, the burr 4 is removed in the direction of moving away from the groove 8 and falling into the square hole 9a. While doing so, it is inserted up to the ridge lines 12b and 12b.

Then, as the punch 10 continues to descend, its cutting blade cuts the connecting piece 2, and at the same time, the burr 4 is also removed and is fitted into the square hole 9a of the die 9, but at this time the punch 4 has already been removed. Because it is directed toward the inside of the square hole 9a,
The removed burr 4 is always removed and falls downward through this square hole 9a, and does not fall into the groove 8 and remain there.

Next, FIG. 4 shows a cutting device according to an embodiment of this invention, in which a required number of punches 10 having the cutting edge shapes shown in FIGS. 3A and 3B are arranged. It has exactly the same effect as Figures A and B.

In this FIG. 4, the stripper 11 is the punch 10.
The lead wires 1, 1a, 1b, . . . , etc. are pressed down before the connecting piece 2 is cut.

Further, FIG. 5 shows a semiconductor device after being cut by the cutting device according to this embodiment.

As described in detail above, when using this invention, a guide protrusion is provided protruding from an inwardly biased part of the cutting edge of the punch, and the surface of the guide protrusion that is connected to the cutting edge is made an inclined surface to facilitate removal. The punch cutting edge is guided to the cutting edge square hole of the die, and both sides of this guide protrusion are sloped surfaces that are gradually downward from a position below the cutting edge surface. Since it is formed so as to lead to the hole, the following effects can be achieved.

In other words, the connecting piece can be cut by fitting the cutting edge of the punch into the square hole of the cutting edge of the die while correcting the distortion of the punch, so there is no breakage of the punch and die, and they are less likely to wear out. The durability of the blade can be increased, and even if the wall thickness of the punch is quite thin and the distortion caused by heat treatment and polishing is larger than the clearance value, it is easy to assemble the mold, and it is easy to use when punching and cutting. Even if side pressure is applied to the punch, there is no risk that the guide protrusion will break even though it is inserted and held in the die.

In addition, the burr that is removed at the same time as the connecting piece is cut is directed by the guide protrusion to be removed into the square hole of the cutting edge of the die prior to cutting, so that the burr that is removed is removed into the groove. It does not remain behind and therefore does not interfere with the next cutting operation, and there is no risk of damaging the semiconductor device during cutting.

In the above embodiment, two guide protrusions are provided, but depending on the shape of the semiconductor device that is the workpiece, one or three or more guide protrusions may be provided. Although this example is given, it goes without saying that there is no problem in arranging them in multiple rows in the same way.

Furthermore, means for maintaining a constant clearance between the bifurcated die and the punch may be implemented in a known manner.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a resin-sealed semiconductor device, FIG. 2 is a perspective view showing the configuration of a conventional thin plate connecting piece cutting device, and FIGS. 3 A and B are an example of this device. Fig. 4 is a perspective view showing the entire cutting device to which the above structure is applied, and Fig. 5 shows an example of a resin-sealed semiconductor device cut by the invented device. FIG. A: Resin-sealed semiconductor device, 1, 1 a, 1 b. ......: Lead wire, 2: Connection piece, 3: Resin coating, 4: Burr, 5: Female mold, 6: Male mold, 7: Die fixing plate, 8: Groove, 9: Die, 9a : Cutting edge square hole of die, 10: Punch, 10a : Cutting edge surface of punch, 1
1 stripper, 12: guide protrusion, 12 a, 1
2 C: slope, 12b: ridgeline.

Claims (1)

[Scope of utility model registration request] A thin plate connecting piece connects a plurality of lead wires pulled out from a resin covering body in which a semiconductor element is resin-sealed, and a punch and its cutting blade are attached to the resin covering side to cut and remove the burr generated during resin sealing. The cutting device includes a die having a square hole into which the punch is inserted, and the cutting device includes a guide protrusion that protrudes at an inner position biased toward the resin coating on the lower side of the cutting blade surface of the punch that is parallel to the surface to be cut. , this guide protrusion is formed as an inclined surface whose outer surface connected to the cutting edge surface is inclined inwardly toward the tip, and which has a lower side than the cutting edge surface on both side surfaces on the lead wire side. 1. A thin plate connecting piece cutting device for a resin-sealed semiconductor device, characterized in that the surfaces are also formed of inclined surfaces that are inclined in a direction that approaches each other toward the tips.