JP7325355B2 - Semiconductor manufacturing equipment and semiconductor device manufacturing method - Google Patents

Description

The present disclosure relates to a semiconductor manufacturing apparatus for cutting tie bar portions of lead frames and a method of manufacturing a semiconductor device using the same.

In the manufacture of semiconductor devices, a lead frame is provided with a tie bar portion to serve as a dam that connects a plurality of leads and prevents resin leakage during resin sealing (molding). Since the potential of each lead is different, it is necessary to cut off the tie bar section connecting the leads after the molding is completed with a tie bar cutting die, but cutting debris is generated when cutting off the tie bar section. At this time, the negative pressure when the upper die of the tie-bar cut die rises, the magnetization of the tie-bar cut die components, wear, or burrs of the cut chips, etc., cause the scrap lifting phenomenon in which the chips are pulled up. I had a problem.

In order to solve such a problem, for example, in Patent Document 1, the leads are supported on the upper surface of the die, the leads are pressed by a stripper plate, and a V-notch punch is brought into contact with the leads to cut them. , a waste-free cutting method is disclosed.

JP-A-6-69394

However, in the technique described in Patent Document 1, the gap between the die that supports the lead and the stripper plate is set wider, and the lead is cut by bending around the contact portion of the V-notch punch. Therefore, there is a problem that the dimensional accuracy of the lead frame is lowered.

Accordingly, an object of the present disclosure is to provide a technique capable of suppressing the generation of cutting debris and suppressing deterioration in the dimensional accuracy of lead frames.

The semiconductor manufacturing apparatus according to the present disclosure includes a punch having a tip portion for cutting the tie bar portion of the lead frame, and the punch movable between a cutting start position and a cutting position located below the cutting start position. a punch guide that supports a punch; and a die that has a recess into which the tip of the punch is inserted while the punch is at the cutting position, and that fixes the tie bar portion between the punch guide and the die. , the tip of the punch has a V- shape protruding downward, and all the points on the inlet side of the recess that come into contact with the tie bar when the punch is in the cutting position are rounded. be.

According to the present disclosure, since the tie bar portion is cut while the tie bar portion is sandwiched and fixed between the die and the punch guide, the dimensional accuracy of the lead frame is prevented from being lowered by eliminating the deflection of the lead frame when cutting the tie bar portion. can be suppressed. Furthermore, since the tip of the convex shape is inserted into the concave portion of the die while the punch is in the cutting position, the tie bar portion can be cut at one point, and the cut portion of the tie bar portion can be bent toward the inner side of the concave portion of the die. Therefore, generation of shavings can be suppressed.

FIG. 2 is a cross-sectional view showing a state where a punch included in the semiconductor manufacturing apparatus according to Embodiment 1 is at a cutting start position; FIG. 2 is a cross-sectional view showing a state in which a punch included in the semiconductor manufacturing apparatus according to Embodiment 1 is at a cutting position; FIG. 10 is a cross-sectional view showing a state in which a punch included in the semiconductor manufacturing apparatus according to Embodiment 2 is at a cutting position; FIG. 11 is a cross-sectional view showing a state where a punch included in a semiconductor manufacturing apparatus according to Embodiment 3 is at a cutting start position; FIG. 11 is a cross-sectional view showing a state where a punch provided in a semiconductor manufacturing apparatus according to Embodiment 3 is at a cutting position; FIG. 11 is a cross-sectional view showing a state where a punch included in a semiconductor manufacturing apparatus according to Embodiment 4 is at a cutting start position; FIG. 11 is a cross-sectional view showing a state in which a punch included in a semiconductor manufacturing apparatus according to Embodiment 4 is at a cutting position;

<Embodiment 1>
Embodiment 1 will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a state in which a punch 6 provided in a semiconductor manufacturing apparatus 1 according to Embodiment 1 is at a cutting start position. FIG. 2 is a cross-sectional view showing a state in which the punch 6 provided in the semiconductor manufacturing apparatus 1 is at the cutting position.

As shown in FIGS. 1 and 2, a semiconductor manufacturing apparatus 1 is an apparatus for cutting tie bar portions 3 connecting a plurality of leads in a lead frame 2 after molding is completed. and a die 7.

The punch 6 has a tip portion 6 a for cutting the tie bar portion 3 of the lead frame 2 . The tip portion 6a has a convex shape protruding downward. More specifically, the tip 6a is V-shaped.

The punch guide 8 moves the punch 6 between a cutting start position (position shown in FIG. 1) and a cutting position located below the cutting start position (position shown in FIG. 2). Supports both sides.

The die 7 is arranged below the punch guide 8 and is a pedestal for fixing the tie bar portion 3 . Specifically, the tie bar portion 3 is fixed while being vertically sandwiched between the punch guide 8 and the die 7 . A concave portion 7a is formed on the upper surface side of the die 7, and the inlet side of the concave portion 7a forms a right angle. The entrance side of the recess 7a includes the entrance-side area inside the recess 7a and the area around the recess 7a on the upper surface of the die 7. As shown in FIG.

Here, since the lead frame 2 includes a plurality of tie bar portions 3, a plurality of recesses 7a are formed and a plurality of punches 6 are also provided. The plurality of recesses 7a are formed at positions corresponding to the tip portions 6a of the punches 6 in the die 7, and by using the plurality of punches 6, it is possible to simultaneously cut the plurality of tie bar portions 3 included in the lead frame 2. is.

As shown in FIG. 2, the tip 6a of the punch 6 is inserted into the recess 7a while the punch 6 is at the cutting position. Moreover, the thickness of the lead frame 2, that is, the thickness of the tie bar portion 3 is 0.2 mm or more and 1.0 mm or less. When the punch 6 is at the cutting position, the distance between the side of the punch 6 and the side of the recess 7a is larger than the thickness of the tie bar 3. Therefore, after the tie bar 3 is cut, the punch 6 is moved upward to the cutting start position. It is possible to move smoothly.

Next, a method for manufacturing a semiconductor device using the semiconductor manufacturing apparatus 1 will be described. First, the lead frame 2 is set so that the tie bar portion 3 is placed on the upper surface of the die 7, and the punch guide 8 is moved downward to sandwich the tie bar portion 3 between the die 7 and the punch guide 8. to fix.

Next, by moving the punch 6 downward from the cutting start position, the tip of the tip portion 6a of the punch 6 comes into contact with the tie bar portion 3, then the tie bar portion 3 is cut by the tip portion 6a, and the punch 6 moves downward. 2, the cut portion of the tie bar portion 3 is sandwiched between the side portion of the punch 6 and the side surface of the recess 7a, and is bent toward the back of the recess 7a.

As described above, the semiconductor manufacturing apparatus 1 according to the first embodiment includes the punch 6 having the tip portion 6a for cutting the tie bar portion 3 of the lead frame 2, the cutting start position, and the cutting portion positioned below the cutting start position. and a punch guide 8 having a recess 7a into which the tip portion 6a of the punch 6 is inserted while the punch 6 is at the cutting position. The punch 6 has a die 7 fixed by sandwiching the tie bar portion 3, and the tip portion 6a of the punch 6 has a convex shape protruding downward.

In addition, the method of manufacturing the semiconductor device according to the first embodiment includes the step (a) of fixing the tie bar portion 3 by sandwiching it between the die 7 and the punch guide 8, and moving the punch 6 from the cutting start position to the cutting position. and a step (b) of cutting the tie bar portion 3 with the tip portion 6a of the punch 6 and bending the cut portion toward the inner side of the concave portion 7a.

Therefore, since the tie bar portion 3 is cut while the tie bar portion 3 is sandwiched and fixed between the die 7 and the punch guide 8, the dimensional accuracy of the lead frame 2 can be improved by eliminating the deflection of the lead frame 2 when cutting the tie bar portion 3. can suppress the decrease in Furthermore, since the convex tip portion 6a is inserted into the recess 7a of the die 7 while the punch 6 is at the cutting position, the tie bar portion 3 is cut at one point, and the cut portion of the tie bar portion 3 is the recess 7a of the die 7. Since it can be bent to the back side of the , it is possible to suppress the generation of cutting waste.

As described above, it is possible to suppress the occurrence of quality troubles due to cutting waste, so that it is possible to improve the yield of semiconductor devices.

<Embodiment 2>
Next, a semiconductor manufacturing apparatus 1A according to Embodiment 2 will be described. FIG. 3 is a cross-sectional view showing a state in which the punch 6 provided in the semiconductor manufacturing apparatus 1A according to Embodiment 2 is at the cutting position. In the second embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

As shown in FIG. 3, in Embodiment 2, the inlet side of the recessed portion 7a has an R-chamfered shape. Alternatively, the inlet side of the concave portion 7a may be chamfered.

In the first embodiment, since the entrance side of the recess 7a is at a right angle, when the cut portion of the tie bar portion 3 is bent at a right angle along the shape of the entrance side of the recess 7a, there is a possibility that the portion will crack. Conceivably, by making the entrance side of the recess 7a into an R-chamfered shape or a C-chamfered shape, the cut portion of the tie bar portion 3 is curved along the shape of the entrance side of the recess 7a.

As described above, in the semiconductor manufacturing apparatus 1A according to the second embodiment, since the entrance side of the concave portion 7a has an R-chamfered shape or a C-chamfered shape, by bending the cut portion of the tie bar portion 3 into a curved shape, the cut portion can be It is possible to suppress the occurrence of cracks in the

<Embodiment 3>
Next, a semiconductor manufacturing apparatus 1B according to Embodiment 3 will be described. FIG. 4 is a cross-sectional view showing a state where the punch 6 provided in the semiconductor manufacturing apparatus 1B according to Embodiment 3 is at the cutting start position. FIG. 5 is a cross-sectional view showing a state in which the punch 6 provided in the semiconductor manufacturing apparatus 1B is at the cutting position. In addition, in Embodiment 3, the same components as those described in Embodiments 1 and 2 are denoted by the same reference numerals, and descriptions thereof are omitted.

As shown in FIG. 4, in the third embodiment, a notch 3a is formed on the back surface of the portion to be cut in the tie bar portion 3. As shown in FIG. The notch 3a has a depth of about 1/3 of the thickness of the tie bar portion 3, and the cross-sectional shape of the notch 3a is formed in a triangular shape with an upper vertex.

In Embodiments 1 and 2, the tip portion 6a of the punch 6 is formed in a V shape. may occur. In this case, the cut position and cut cross-sectional shape of the tie bar portion 3 may become unstable, and the dimensional accuracy of the lead frame 2 may deteriorate.

As shown in FIGS. 4 and 5, in the third embodiment, the notch 3a is formed on the back surface of the portion to be cut in the tie bar portion 3. Therefore, the stress applied when cutting the tie bar portion 3 concentrates on the notch 3a, The tie bar portion 3 can be cut along the notch 3a.

Next, a method for forming the notch 3a will be described. Before the tie bar portion 3 is sandwiched and fixed between the die 7 and the punch guide 8, the tie bar portion 3 is pushed into the die having a projection corresponding to the shape of the notch 3a, so that the back surface of the portion to be cut in the tie bar portion 3 is cut. A notch 3a is formed. Next, after conveying the lead frame 2 for one package, steps (a) and (b) are performed in the same manner as in the first and second embodiments.

As described above, the method of manufacturing a semiconductor device according to the third embodiment further includes the step (c) of forming the notch 3a on the back surface of the portion to be cut in the tie bar portion 3 before the step (a). there is

Therefore, even if the tip portion 6a is worn, the stress applied when cutting the tie bar portion 3 concentrates on the notch 3a, and the tie bar portion 3 can be cut along the notch 3a. Furthermore, since the thickness of the portion to be cut in the tie bar portion 3 is reduced, the tie bar portion 3 can be cut with a low load.

Note that the cross-sectional shape of the notch 3a is not limited to a triangular shape, and may be a groove shape. This facilitates positioning control of the punch 6 and the cutting portion of the tie bar portion 3 .

<Embodiment 4>
Next, a semiconductor manufacturing apparatus 1C according to Embodiment 4 will be described. FIG. 6 is a cross-sectional view showing a state where the punch 16 provided in the semiconductor manufacturing apparatus 1C according to the fourth embodiment is at the cutting start position. FIG. 7 is a cross-sectional view showing a state in which the punch 16 provided in the semiconductor manufacturing apparatus 1C is at the cutting position. In Embodiment 4, the same components as those described in Embodiments 1 to 3 are denoted by the same reference numerals, and descriptions thereof are omitted.

As shown in FIGS. 6 and 7, in the fourth embodiment, a semiconductor manufacturing apparatus 1C has a punch 16 having a tip portion 16a instead of the punch 6. As shown in FIGS. The tip portion 16a has a convex shape having a vertical portion 16b and an inclined portion 16c. Further, the portion facing the vertical portion 16b on the inlet side of the recess 7a is a right angle, and the other portions on the inlet side of the recess 7a are R chamfered or C chamfered. Further, when the punch 16 is at the cutting position, the distance between the side of the punch 16 on the cutting side of the tie bar 3 and the side of the recess 7a is the same as the side of the punch 16 on the bending side of the tie bar 3 and the recess 7a. It is smaller than the distance from the side of 7a. Specifically, the distance between the side portion of the punch 16 and the side surface of the concave portion 7a on the cutting side of the tie bar portion 3 is about 8% or more and 10% or less of the thickness of the tie bar portion 3 .

When the lead frame 2 is thick (for example, 0.5 mm or more), in the configuration of the first embodiment, when the tip of the punch 6 presses the tie bar 3, the pressed portion of the tie bar 3 expands. , may not lead to cutting.

In Embodiment 4, by adopting the above configuration, the shearing force of the punch 16 can be increased, so that stable cutting becomes possible.

As described above, in the semiconductor manufacturing apparatus 1C according to the fourth embodiment, the tip portion 16a of the punch 16 has the vertical portion 16b and the inclined portion 16c, and the portion facing the vertical portion 16b on the entrance side of the concave portion 7a is Right angle.

Therefore, since the shearing force of the punch 16 can be increased, stable cutting is possible even when the thickness of the lead frame 2 is large. Further, since the tip portion 16a of the punch 16 is provided with an inclined portion 16c, it can be bent toward the inner side of the concave portion 7a without cutting off the cut portion of the tie bar portion 3, thereby suppressing the generation of cutting chips.

In addition, it is possible to freely combine each embodiment, and to modify or omit each embodiment as appropriate.

Reference Signs List 1, 1A, 1B, 1C semiconductor manufacturing equipment, 2 lead frame, 3 tie bar portion, 3a notch, 6 punch, 6a tip portion, 7 die, 7a concave portion, 8 punch guide, 16 punch, 16a tip portion, 16b vertical portion , 16c ramp.

Claims (4)

a punch having a tip portion for cutting the tie bar portion of the lead frame;
a punch guide that supports the punch so as to be movable between a cutting start position and a cutting position located below the cutting start position;
a die that has a recess into which the tip of the punch is inserted while the punch is in the cutting position, and that holds and fixes the tie bar portion with the punch guide;
The tip of the punch has a V shape protruding downward ,
A semiconductor manufacturing apparatus according to claim 1, wherein, when the punch is in the cutting position, all portions on an entrance side of the recess that come into contact with the tie bar portion have an R-chamfered shape. 2. The semiconductor manufacturing apparatus according to claim 1 , wherein when said punch is in said cutting position, a distance between a side portion of said punch and a side surface of said recess is larger than the thickness of said tie bar portion. A manufacturing method for manufacturing a semiconductor device using the semiconductor manufacturing apparatus according to claim 1 or claim 2 ,
(a) a step of sandwiching and fixing the tie bar portion between the die and the punch guide;
(b) a step of moving the punch from the cutting start position to the cutting position, thereby cutting the tie bar portion with the tip portion of the punch and bending the cut portion toward the inner side of the recess;
A method of manufacturing a semiconductor device, comprising: 4. The method of manufacturing a semiconductor device according to claim 3 , further comprising the step of: (c) forming a notch in the rear surface of said tie bar portion at a portion to be cut in said tie bar portion before said step (a).

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