JP2001210773A - Tie bar cutting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable to set tapered angles of a dram resin punching part and a tie bar cutting part individually to the optimum angles, and eliminate abnormal wear or the like of the dam rein punching part. SOLUTION: In a tie bar cutting punch 5, the dam resin punching part 6 and the tie bar cutting part 7 are formed in the moving direction to an outer lead 2 of the tie bar cut punch 5 in such a manner that the boundary of the dam resin punching 6 and the tie bar cutting part 7 is isolated by an upright side wall 8. As a result, time difference is set between the removal of dam resin 4 and the cutting of the tie bar 3, so that mutual interference between the removal of the dam resin 4 and the cutting of the tie bar 3 is excluded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tie bar cutting device for removing a tie bar and a dam resin from outer leads of a resin-encapsulated semiconductor device in a semi-finished state by a tie bar cut punch.

[0002]

2. Description of the Related Art As a semiconductor device, there is a resin-sealed semiconductor device in which an outer periphery is covered with a sealing resin for hermetic sealing.

As shown in FIG. 3, a resin-encapsulated semiconductor device of this type generally has an outer lead 2 projecting laterally from a package body 1 and a tie bar 3 between the adjacent outer leads 2 and 2. In this state, the manufacturing process up to resin sealing is performed, and after the resin sealing, the tie bar 3 and the dam resin 4 are removed to produce a semi-finished resin-sealed semiconductor device as a final product. A process for molding into a resin-sealed semiconductor device is performed.

For the above-mentioned molding process, a tie bar cutting device is used for removing a tie bar and a dam resin from an outer lead of a resin-sealed semiconductor device in a semi-finished state by a tie bar cut punch.

A tie bar cutting device of this type is disclosed in Japanese Utility Model Laid-Open No. 2-81721. In the tie bar cutting device disclosed in Japanese Utility Model Application Laid-Open No. 2-81721, a punching surface of a dam resin punching portion is formed by a dam. A tie-bar cutting device disclosed in Japanese Patent Application Laid-Open No. 11-26669 has been developed because the resin collides with the entire surface to apply stress, and the wear is severe.

A tie bar cutting device disclosed in Japanese Patent Application Laid-Open No. Hei 11-26669 will be described with reference to FIG. The tie bar cutting device shown in FIG. 3 has a tie bar cutting punch 10 in which a dam resin punching portion 11a and a tie bar cutting portion 11b are integrally provided, and a punching surface of the dam resin punching portion 11a and a tie bar cutting portion 11b are cut. The cut surface of the dam resin punched portion 11a and the cut surface of the tie bar cut portion 11b are formed as continuous tapered surfaces having the same inclination angle.

The tie bar cut punch 10 is supported by a punch guide 12 so as to move up and down.

In the tie bar cutting device shown in FIG. 3, first, the dam resin 4 is punched at the tip 11c of the punching surface of the dam resin punching portion 11a, and at the same time as the dam resin punching process by the dam resin punching portion 11a. Tie bar cut part 1
The tie bar 3 is cut on the cut surface 1b.

[0009]

However, in the tie bar cutting device shown in FIG. 3, the punched surface of the dam resin punched portion 11a and the cut surface of the tie bar cut portion 11b are integrally formed with a continuous tapered surface. There is a period during which the punching of the dam resin 4 by the dam resin punching portion 11a and the cutting of the tie bar 3 of the tie bar cutting portion 11b are performed in parallel after the tip 11c of the punching surface of the portion 11a abuts against the dam resin 4. When the tapered angle of the punched surface of the dam resin punched portion 11a is set to an optimum angle for punching, the tapered angle of the cut surface of the tie bar cut portion 11b is regulated by the angle, and the taper angle of the tie bar cut portion 11b is adjusted. It does not provide the optimum taper angle on the cut surface, and hinders the cutting of the tie bar 3 by the tie bar cut portion 11b. , Problems with the bad cut is generated in the concrete.

From the above circumstances, the angle of the continuous tapered surface integral with the punched surface of the dam resin punched portion 11a and the cut surface of the tie bar cut portion 11b is limited to a compromised range that does not hinder the punching and cutting. As a result, the tip 11 of the dam resin punched portion 11a that first comes into contact with the dam resin 4
There is a problem in the actual machine that an excessive force is applied to c and the protruding end 11c of the dam resin punched portion 11a is abnormally worn.

Therefore, the tie bar cutting device disclosed in Japanese Patent Application Laid-Open No. 63-302545 separates the punching by the dam resin punching section and the cutting by the tie bar cutting section as shown in FIGS. 4 (a) and 4 (b). The tie bar cut punch 10 is provided with a punch protrusion 12 and a tie bar cut portion 7, and the tie bar 3 is cut off by the punch protrusion 12 of the tie bar cut punch 10 with the dam resin 4 left. At the same time, the auxiliary lead 13 is removed by the tie bar cut portion 7.

However, the tie bar cutting device shown in FIG. 4 has been developed on the premise that punching of the dam resin by the dam resin punching portion and cutting of the tie bar 3 and the auxiliary lead 13 by the tie bar cutting portion 7 are performed in separate processes. ,
It is necessary to separately provide a transport mechanism between the processes and a dam resin removing mechanism, and there is a problem in terms of efficiency, equipment cost, and the like.

An object of the present invention is to provide a tie bar cutting device which can set the taper angle of the dam resin punching portion and the tie bar cut portion individually to an optimum angle and eliminates abnormal wear and the like of the dam resin punching portion. It is in.

[0014]

In order to achieve the above object, a tie bar cutting apparatus according to the present invention removes a tie bar and a dam resin from an outer lead of a resin-encapsulated semiconductor device in a semi-finished state by a tie bar cut punch. Tie bar cutting device for cutting the tie bar with a time delay after removing the dam resin.

Further, the tie bar cut punch is provided with a dam resin punching portion and a tie bar cut portion separated from each other, so that there is a time difference between the removal of the dam resin and the cutting of the tie bar.

The dam resin punching portion and the tie bar cutting portion are separated from each other in a direction in which the tie bar cutting punch moves to the outer lead side of the package body, and the dam resin punching portion and the tie bar cutting portion are shifted in position. The time difference is provided between the removal of the dam resin and the cutting of the tie bar.

Further, the tie bar cut punch has a dam resin punched portion and a tie bar cut portion with tapered surfaces.

The dam resin punched portion and the tie bar cut portion have tapered surfaces having the same inclination angle.

The dam resin punched portion and the tie bar cut portion have tapered surfaces having different inclination angles.

Further, the boundary between the dam resin punched portion and the tie bar cut portion is separated by a steep side wall.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

The tie bar cutting device according to the present invention shown in FIGS. 1 and 2 is used for removing a tie bar 3 and a dam resin 4 from a package body 1 of a resin-encapsulated semiconductor device in a semi-finished state by a tie bar cut punch 5. The present invention is directed to a tie bar cutting device, wherein the tie bar 3 is cut with a time delay after the dam resin 4 is removed.

More specifically, the tie bar cutting device according to the present invention is provided with a tie bar cut punch 5 in which a dam resin punching portion 6 and a tie bar cut portion 7 are separated from each other, so that there is a time difference between the removal of the dam resin 4 and the cutting of the tie bar 3. It is the one that was given.

Further, the dam resin punching section 6 and the tie bar cutting section 7 are separated in the moving direction of the tie bar cutting punch 5 with respect to the outer lead 2, and the dam resin punching section 6 is separated.
The position of the tie bar cut portion 7 is shifted from the position of the tie bar cut portion 7 so that there is a time difference between the removal of the dam resin 4 and the cutting of the tie bar 3.

The dam resin punched portion 6 and the tie bar cut portion 7 of the tie bar cut punch 5 are provided with tapered surfaces 6a, 7a, and the dam resin punched portion 6 and the tie bar cut portion 7 have the same taper surface 6a. , 7a,
Alternatively, the dam resin punched portion 6 and the tie bar cut portion 7 are provided with tapered surfaces 6a, 7a having different inclination angles.

Further, a boundary between the dam resin punching portion 6 and the tie bar cut portion 7 is separated by a steep side wall 8.

As described above, according to the tie bar cutting device according to the present invention, the tie bar 3 is cut with a time delay after the dam resin 4 is removed. The tie bar 3 can be cut completely by the tie bar cut portion 7 after the dam resin 4 is punched out without being affected by the cut of the tie bar 3 by the portion 7.

Further, the tie bar cutting device according to the present invention
The tie bar cut punch 5 is provided with a dam resin punching portion 6 and a tie bar cut portion 7 which are separated from each other to provide a time difference between the removal of the dam resin 4 and the cutting of the tie bar 3. The dam resin punching part 6 and the tie bar cutting part 7 are separated in the moving direction, and the dam resin punching part 6 and the tie bar cutting part 7 are provided so as to be displaced from each other. Therefore, it is possible to prevent mutual interference between the punching of the dam resin 4 by the dam resin punching section 6 and the cutting of the tie bar 3 by the tie bar cutting section 7.

Further, tapered surfaces 6a, 7a are formed on the dam resin punching portion 6 and the tie bar cutting portion 7 of the tie bar cutting punch 5.
The dam resin punched portion 6 and the tie bar cut portion 7 are provided with tapered surfaces 6a, 7a having the same inclination angle, or the dam resin punched portion 6 and the tie bar cut portion 7 are provided with different taper angles. Since the surfaces 6a and 7a are formed, the tapered surface 6a of the dam resin punched portion 6 is formed.
Can be set to the optimum angle for the punching, and the taper angle at the tapered surface 7a of the tie bar cut portion 7 can be set to the optimum angle for the cutting without being affected by the angle. It is possible to eliminate the restriction that the taper angle between the punched surface of the dam resin punched portion and the cut surface of the tie bar cut portion is set in a compromise range that does not interfere with punching and cutting as in the conventional example shown, Eliminating excessive force from being applied to the protruding end 6b of the dam resin punching portion 6 abutting on the resin 4 and eliminating the protruding end 6b of the dam resin punching portion 6
b can be prevented from being abnormally worn.

Further, the boundary between the dam resin punched portion 6 and the tie bar cut portion 7 is separated by a steep side wall 8 so that mutual interference at the boundary between the dam resin punched portion 6 and the tie bar cut portion 7 is achieved. Can be cut off.

Next, the present invention will be described in detail with reference to specific examples.

FIG. 1A is a plan view showing a tie bar cutting device according to one embodiment of the present invention, and FIG. 1B is a sectional view showing a tie bar cutting device according to one embodiment of the present invention.

As shown in FIG. 1, the tie bar cut punch 5 is supported by a punch guide 9 so as to move up and down. When the tie bar cut punch 5 descends, the dam resin punching section 6 and the tie bar cut section of the tie bar cut punch 5 are moved. 7, the dam resin 4 is removed and the tie bar 3 is cut.

In the tie bar cutting device according to one embodiment of the present invention, the tie bar cut punch 5 is provided with the dam resin punching portion 6 and the tie bar cut portion 7 separated from each other, so that there is a time difference between the removal of the dam resin 4 and the cutting of the tie bar 3. More specifically, the dam resin punching portion 6 and the tie bar cutting portion 7 move in the moving direction of the tie bar cutting punch 5 with respect to the outer lead 2.
And the dam resin punched portion 6 and the tie bar cut portion 7 are provided so as to be shifted from each other.
Is removed so that there is a time difference between the removal of the dam resin 4 and the cutting of the tie bar 3 so that the tie bar 3 is cut with a time delay.

Further, the boundary between the dam resin punching portion 6 and the tie bar cut portion 7 is separated by a steep side wall 8 so as to cut off the mutual interference between the removal of the dam resin 4 and the cutting of the tie bar 3.

The tie bar cut punch 5 has a tapered surface (cutting surface) 6a on the dam resin punched portion 6 and a tie bar cut portion 7 with a tapered surface (cut surface) 7a. Whether the tie bar cut portion 7 is provided with tapered surfaces 6a and 7a having the same inclination angle (see FIG. 1),
Alternatively, the dam resin punched portion 6 and the tie bar cut portion 7 are provided with tapered surfaces 6a, 7a having different inclination angles. Die resin punching part 6 of tie bar cut punch 5
By providing the punched surface 6a and the cut surface 7a of the tie bar cut portion 7 in a tapered shape, the cutting load applied to the outer lead 2 and the tie bar 3 by the tie bar cut punch 5 is reduced.

The operation of the tie bar cutting device according to one embodiment of the present invention will be described. Outer leads 2 protrude laterally from the package body 1 of the resin-sealed semi-finished resin-sealed semiconductor device, and the outer leads 2 adjacent thereto are connected to each other with a tie bar 3 for reinforcement. In this state, a manufacturing process up to resin sealing is performed. In that case, the sealing resin is filled in a space surrounded by the package body 1, the outer leads 2, and the tie bars 3, and this remains as the dam resin 4. Therefore, the dam resin 4 is removed after the resin sealing, and It is necessary to cut the tie bar 3 to electrically separate the outer leads 2 individually.

First, the package body 1 of the semi-finished product after resin sealing is set and fixed on a die (not shown).

In this state, when the tie bar cut punch 5 is guided and lowered by the punch guide 9, the protruding end 6 b of the punching surface 6 a of the dam resin punching portion 6 located at the tip end side of the tie bar cut punch 5 is attached to the package body 1. The end 6b of the punched surface 6a, especially the end 6b
Stress is intensively applied to the dam resin 4 from the corner of the dam resin 4 to form a crack in the dam resin 4. Then, almost the entire tapered surface of the punched surface 6 a contacts almost the entire dam resin 4 and Is pressed down by the tapered surface of the punching surface 6a. Thereby, the dam resin 4 can be completely removed by the dam resin punching portion 6 without being affected by the cutting of the tie bar 3, and the tie bar cutting portion 7 can be removed after the dam resin 4 is punched. Is cut out with the tie bar 3 on the cut surface 7a.

After the dam resin 4 is punched and removed by the dam resin punching section 6, the tie bar cut punch 5 is further guided by the punch guide 9 to be lowered. Hit 3

In this case, since the cut surface 7a of the tie bar cut portion 7 is formed in a tapered shape, the cut surface 7a of the tie bar cut portion 7 abuts in an inclined state, that is, in a state of line contact with the tie bar 3, Stress is concentrated on the tie bar 3 from the contact portion, and a crack is formed in the tie bar 3. Then, almost the entire tapered surface of the cut surface 7 a contacts almost the entire surface of the tie bar 3, and the entire surface of the tie bar 3 is cut. The pressure is reduced on the tapered surface 7a. Thus, the tie bar 3 of the package body 1 is cut by the tie bar cutting unit 7.

As described above, according to the embodiment of the present invention,
Tie bar 3 with time delay after removing dam resin 4
Can be completely cut out by the dam resin punching section 6 without being affected by the cutting of the tie bar 3 by the tie bar cutting section 7, and after the dam resin 4 is punched, the tie bar Cut surface 7 of cut part 7
The tie bar 3 can be cut by a.

Further, the tie bar cut punch 5 is provided with a dam resin punching section 6 and a tie bar cut section 7 separated from each other, so that there is a time difference between the removal of the dam resin 4 and the cutting of the tie bar 3. Tie bar cut part 7
And the tie bar cutting punch 5 is provided so as to be shifted in the moving direction of the outer lead 2 with respect to the outer lead 2, so that there is a time difference between the removal of the dam resin 4 and the cutting of the tie bar 3. Of the dam resin 4 and the cut of the tie bar 3 by the tie bar cut portion 7 can be prevented from interfering with each other.

Further, tapered surfaces 6a, 7a are formed on the dam resin punched portion 6 and the tie bar cut portion 7 of the tie bar cut punch 5.
The dam resin punched portion 6 and the tie bar cut portion 7 are provided with tapered surfaces 6a, 7a having the same inclination angle, or the dam resin punched portion 6 and the tie bar cut portion 7 are provided with different taper angles. Since the surfaces 6a and 7a are formed, the punched surface 6a of the dam resin punched portion 6 is formed.
3 can be set to an optimum taper angle for punching, and the taper angle at the cut surface 7a of the tie bar cut portion 7 can be set to an optimum taper angle for cutting without being affected by the angle. It is possible to eliminate the restriction that the taper angle between the punched surface of the dam resin punched portion and the cut surface of the tie bar cut portion is set in a compromise range that does not interfere with the punching and cutting as in the conventional example shown in It is possible to prevent an excessive force from being applied to the protruding end 6b of the dam resin punching portion 6 which comes into contact with the dam resin 4, thereby preventing the protruding end 6b of the dam resin punching portion 6 from being abnormally worn.

Further, the boundary between the dam resin punched portion 6 and the tie bar cut portion 7 is separated by the steep side wall 8, so that mutual interference at the boundary between the dam resin punched portion 6 and the tie bar cut portion 7 is achieved. Can be cut off.

Further, as shown in FIGS. 2A and 2B, a dam resin punching portion 6 formed at the lower end of a tie bar cut punch 5 for punching the dam resin 4 The contact between the package main body 1 and the outer lead 2 is taken into account in consideration of the positional deviation that occurs during the formation of the die 1, the deviation when positioning the outer lead 2 with the tie bar cutting die, and the mounting error of the tie bar cut punch 5 into the tie bar cutting die. The tie bar cut punch 5 is guided by a punch guide 9 with an extremely small clearance (about 0.05 mm) C1, C2, C3, and C4 so as to operate.

Further, before the dam resin punching portion 6 cuts the tie bar 3, it comes into contact with the dam resin 4, and the protruding end 6 b cuts in from the dam resin 4 side adjacent to the package body 1 having high adhesion force. When the taper angle is too acute, the abrasion of the tip 6b is accelerated. Therefore, the taper angle of the punched surface 6a is set to about 85 ° with respect to the steep reference surface 8a of the tie bar cut punch 5.

Further, the displacement h in the height direction between the punched surface 6a and the cut surface 7a separated by the side wall 8 which is steep at the boundary between the dam resin punched portion 6 and the tie bar cut portion 7, that is, the punching of the dam resin 4 The ejection amount h is set to about twice (h ≒ 2t) the thickness t of the outer lead 2. As a result, it is possible to prevent the dam resin 4 from sagging and remove the dam resin 4 from the space surrounded by the package body 1 and the outer leads 2.

[0049]

As described above, according to the present invention, the taper angles of the dam resin punching portion and the tie bar cut portion can be individually set to optimum angles, and abnormal wear of the dam resin punching portion can be eliminated. be able to.

[Brief description of the drawings]

FIG. 1A is a plan view showing a tie bar cutting device according to one embodiment of the present invention, and FIG. 1B is a cross-sectional view showing a tie bar cutting device according to one embodiment of the present invention.

FIG. 2A is a plan view showing details of a tie bar cutting device according to an embodiment of the present invention, and FIG. 2B is a cross-sectional view showing details of a tie bar cutting device according to an embodiment of the present invention. .

FIG. 3 is a cross-sectional view illustrating a tie bar cutting apparatus according to a conventional example.

FIG. 4A is a plan view illustrating a tie bar cutting device according to a conventional example, and FIG. 4B is a cross-sectional view illustrating a tie bar cutting device according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Package main body 2 Outer lead 3 Tie bar 4 Dam resin 5 Tie bar cut punch 6 Dam resin punched part 6a Die resin punched surface 7 Tie bar cut part 7a Tie bar cut part cut surface (taper surface) 8 Side wall 9 Punch guide

Claims (7)

[Claims] 1. A tie bar cutting device for removing a tie bar and a dam resin from an outer lead of a resin-encapsulated semiconductor device in a semi-finished state by a tie bar cut punch, wherein the tie bar cutting device has a time delay after removing the dam resin. A tie bar cutting device characterized by cutting a tie bar. 2. The tie bar cut punch is provided with a dam resin punching portion and a tie bar cut portion separated from each other, and a time difference is provided between the removal of the dam resin and the cutting of the tie bar. Tie bar cutting equipment. 3. A dam resin punching portion and a tie bar cut portion are separated in a direction in which the tie bar cut punch moves to the outer lead side of the package body, and the positions of the dam resin punching portion and the tie bar cut portion are shifted. The tie bar cutting device according to claim 1 or 2, wherein a time difference is provided between the removal of the dam resin and the cutting of the tie bar. 4. The tie bar cutting device according to claim 1, wherein the tie bar cut punch has a tapered surface on a dam resin punching portion and a tie bar cut portion. 5. The tie bar cutting device according to claim 4, wherein the dam resin punched portion and the tie bar cut portion have tapered surfaces having the same inclination angle. 6. The tie bar cutting device according to claim 4, wherein the dam resin punched portion and the tie bar cut portion have tapered surfaces having different inclination angles. 7. The tie bar cutting device according to claim 1, wherein a boundary between the dam resin punched portion and the tie bar cut portion is separated by a steep side wall. .