JP2538431Y2 - Semiconductor crusher - Google Patents

Description

[Detailed description of the invention]

[Purpose of the invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor crushing apparatus for crushing burrs attached to outer leads of a resin-encapsulated semiconductor.

[0003]

2. Description of the Related Art Generally, in molding a resin-encapsulated semiconductor, for example, as disclosed in Japanese Patent Publication No. 63-5912, supply of a lead frame and a resin tablet is followed by resin encapsulation. A device that automatically performs all the steps up to the storage is used. However,
As shown in FIG. 8, the resin-encapsulated semiconductor formed by the above-described apparatus has outer leads 3 formed so as to connect between the resin cavity 1 and the lead frame 2. Since the burrs 4 are attached, the burrs 4 need to be removed.

Conventionally, in order to remove the burrs 4, a resin-encapsulated semiconductor is set on a lower die, and the upper die is lowered by an air press, a hydraulic press, a crank press, or the like. A semiconductor crushing device that crushes the burrs 4 between the lower mold and the lower mold has been used.

[0005]

However, the thickness of the resin-encapsulated semiconductor lead frame 2 is 0.1 to 0.1.
Therefore, the crush amount of the outer lead 3 is a minute value of 0.03 to 0.05 mm. For this reason, the permissible variation limit when the outer lead 3 is crushed is a minute figure of 0.02 mm.

In order to maintain and adjust the above tolerance of 0.02 mm, it is advantageous to use an air press or a hydraulic press that can reliably perform crushing until the crushing force and the applied pressure are balanced. However, in these press methods, the lowering speed of the upper mold is slow, which is not suitable for mass production. Then, there is an attempt to crush many resin-encapsulated semiconductors at once to make it suitable for mass production, but in this case, there is a problem that a large-sized hydraulic press or the like is required.

On the other hand, the crank press has a high descending speed of the upper die, and can crush about 120 times per minute. In this respect, the crank press is more advantageous than the air press or the hydraulic press. However, on the other hand, it is difficult for the crank press to adjust the lower limit position of the upper die,
There is a problem that it takes a lot of time to adjust the variation tolerance of 0.02 mm. Further, during use, each sliding portion is worn, and variation occurs in the lower limit position of the upper mold. there were. Further, in the crank press, since the upper die descends to the press maximum bottom dead center even after contacting the lower die, the maximum pressing force occurs at the press maximum bottom dead center, and as a result, There is also a disadvantage that the durability of the device is reduced.

The present invention has been made in view of the above circumstances, and its purpose is to perform a lot of crushing in a short period of time, and to easily adjust the lower limit position of the upper mold, and to surely An object of the present invention is to provide a highly durable semiconductor crushing device capable of performing crushing within a variation allowable limit range.

[Structure of Device]

[0010]

In order to achieve the above object, a semiconductor crushing device according to the present invention comprises an upper die held by an upper die base which is moved up and down by a crank mechanism of a press mechanism;
Collision and the lower mold, the upper mold is held in the upper die to hold the retained trees Aburafutome type semiconductor in the lower mold base of the press Organization
A punch that is provided with the upper die, and lowering the upper die base to crush burrs attached to outer leads of the resin-encapsulated semiconductor between the punch and the lower die. one side of said the stopper to limit the contact with the lower limit position of the upper die relative to said lower die at the time of the other crushing one to the provided beams of lower mold, and the lower die and the upper die and It characterized in place with an elastic member elastically deformed to provided to permit downward movement of the upper die base and the stopper abutting time after an elastic force that may against the crushing force of the beams in.

[0011]

When the upper base is lowered, the elastic member has an elastic force capable of resisting the crushing force of the outer lead, so that the crushing force of the upper base acts on the burrs attached to the outer lead. Is peeled off. In this case, since the upper die base is configured to move up and down by the crank mechanism, a lot of crushing can be performed in a short time.

At the same time as the upper die is lowered and the outer lead is crushed by a predetermined amount, the stopper comes into contact with the lower die and the amount of crush of the outer lead is limited. It is only necessary to adjust the length of the stopper, and since the sliding part does not wear out and the lower limit position of the upper die does not vary as in the past, it is easy to adjust the lower limit position of the upper die. It is possible to reliably perform crushing within the allowable range of variation.

After the stopper abuts, the upper die descends until it reaches the maximum bottom dead center of the press. However, one of the upper die and the lower die has the upper die after the stopper abuts. An elastic member that is elastically deformed so as to allow the lowering of the mold base is provided. Since the elastic member allows the lowering of the upper mold, it absorbs an excessive force applied to the lower mold. The impact force generated between the mold and the lower mold can be reduced, and the durability can be improved.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is for crushing a flash 4 adhered to a resin-encapsulated semiconductor as shown in FIG. 8, and one embodiment thereof will be described below with reference to FIGS. explain. First, in FIGS. 1 and 2, an upper die 12 is attached to an upper die base 11 connected to a ram (not shown) of a crank press as a press mechanism (not shown). The upper die 12 can be moved up and down by a crank mechanism of a crank press. The upper die 12 is formed by attaching the backing plate 1 to the upper die set 13.
4, a punch plate 15 is attached to the backing plate 14, and a punch 16 is pressed and fixed to the punch plate 15.
, And the impact force applied to the punch 16 during crushing can be reduced.

FIG. 3 is an enlarged view of the punch 16. As shown in FIG.
Groove portion 1 fitted into resin cavity 1 of resin-encapsulated semiconductor
A V-shaped groove 1 for crushing the outer lead 3 and peeling off the burrs 4 is formed on both sides of the groove 17.
8 are formed.

On the other hand, the punch plate 15 of the upper die 12
Has a stopper 19 attached thereto. A bolt 20 is embedded in the stopper 19. The bolt 20 is screwed into the punch plate 15 to
9 is fixed to the punch plate 15.

Lower mold 21 and lower mold base 2 holding the same
Elastic members 23, 23 are interposed between the two. These elastic members 23, 23 have an elastic force capable of withstanding a crushing force (P) necessary to crush the outer lead 3 by a predetermined amount (S), and the elastic members 23, 23 After the lower mold 19 comes into contact with the lower mold 21, the upper mold 12 is elastically deformed so as to be allowed to descend.

A concave portion 24 is formed at the center of the lower die 21, and a resin-sealed semiconductor is set in the concave portion 24 when crushed. Furthermore, the lower mold 21
Is formed with an insertion hole 25, in which a shoulder bolt 26 is inserted. One end of the shoulder bolt 26 is fixed to the lower mold base 22. When the elastic members 23 are elastically deformed, the lower mold 21 slides in the vertical direction using the shoulder bolt 26 as a guide. I have.

Next, the operation of the above configuration will be described.
As shown in FIG. 1, when the resin-encapsulated semiconductor is set in the recess 24 of the lower mold 21, the upper mold base 11 connected to the ram of the crank press descends as shown in FIG. The punch 16 of the mold 12 contacts the outer lead 3 of the resin-encapsulated semiconductor. In this case, since the elastic members 23 have an elastic force that can withstand a force (P) required for the outer lead 3 to be crushed by a predetermined amount (S), the crushing force by the upper mold 12 is small. , Acting on the outer lead 3, and as shown in FIG.
It gradually increases with the fall of. Then, as shown in FIG. 5, the outer lead 3 is crushed by a predetermined amount S,
The stopper 19 abuts on the lower mold 21 at the same time as is peeled off, and the crushing amount of the outer lead 3 is limited to the predetermined amount S.

Even after the stopper 19 comes into contact with the lower die 21, the upper die 12 descends until it reaches the maximum bottom dead center of the press. In this case, the lower die 21 and the lower die base 22 Elastic members 23, 23 are interposed between them.
After the stopper 19 contacts the lower mold 21 (the elastic member 2
After the force applied to the lower die 3 becomes 23, the elastic members 23, 23 are elastically deformed and contracted to allow an excessive force applied to the lower die 21 as the upper die 12 is lowered. The excessive pressing force equal to or greater than the crushing force P is absorbed by the elastic members 23 and 23, and the magnitude thereof is maintained at P until the upper die 12 reaches the maximum bottom dead center of the press.

When the upper die 12 reaches the maximum bottom dead center of the press, the upper die base 11 and the upper die 12 also rise with the rise of the ram, and the crushing ends. Then, a transport device (not shown) is operated, and the resin-encapsulated semiconductor is transported by 10 to 20 mm by the guide plate 27, and is crushed again.

According to the above configuration, the following effects can be obtained. That is, since the upper mold base 11 is configured to be moved up and down by a crank press, it is possible to perform a lot of crushing in a short time.

At the same time that the upper die 12 is lowered to crush the outer lead 3 by a predetermined amount S, the stopper 1
The lower die 9 is in contact with the lower die 21 so that the amount of crush of the outer lead 3 is limited, so that the lower limit position of the upper die 12 can be adjusted simply by adjusting the length of the stopper 19, and can be easily performed. be able to. In this case, unlike the related art, the sliding portion does not wear and the lower limit position of the upper mold does not vary, and the crushing can be reliably performed within the variation allowable limit range.

Further, the crushing force (P) required for crushing the outer leads 3 by a predetermined amount (S) is applied to the elastic members 23, 23.
The stopper 19 is elastically deformable to allow the upper mold 12 to descend after the stopper 19 comes into contact with the lower mold 21.
During the period from the contact with the first contact member 1 to the maximum bottom dead center of the press, the excessive pressing force applied to the lower mold 21 is absorbed by the elastic member 23. As a result, the pressing force applied to the outer lead 3 is reduced to a constant value P. Can be held. Therefore, the impact force generated between the upper die 12 and the lower die 21 at the maximum bottom dead center of the press can be reduced, and the durability can be improved.

In the above embodiment, the elastic members 23, 23 are interposed between the lower mold base 22 and the lower mold 21. However, as shown in FIG.
The elastic members 23, 23 may be provided between them.

[0026]

As is apparent from the above description, according to the semiconductor crushing device of the present invention, the upper die base is provided to be moved up and down by the crank mechanism of the press mechanism, and one of the upper die and the lower die is provided. A stopper that abuts against the other at the time of crushing to limit the lower limit position of the upper mold with respect to the lower mold, and that one of the upper mold and the lower mold resists the crushing force of the burrs. Since an elastic member having an elastic force to be obtained and elastically deforming so as to allow the upper mold base to descend after the stopper abutment is provided, many crushing can be performed in a short time, and It is possible to easily adjust the lower limit position, to reliably perform crushing within the allowable variation range, and to improve the durability.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a view corresponding to FIG. 1 when a resin-sealed semiconductor is crushed.

FIG. 3 is a bottom view of the punch.

FIG. 4 is a side view of the punch.

FIG. 5 is an enlarged longitudinal sectional view showing a crushed state of an outer lead.

FIG. 6 is a characteristic diagram showing a relationship between a pressing force applied to an outer lead and a crushing amount.

FIG. 7 is a view corresponding to FIG. 2 showing another embodiment of the present invention.

FIG. 8 is a perspective view of a resin-sealed semiconductor.

[Explanation of symbols]

3 is an outer lead, 4 is a burr, 11 is an upper base, 1
Reference numeral 2 denotes an upper die, 16 denotes a punch, 19 denotes a stopper, 21 denotes a lower die, 22 denotes a lower die base, and 23 denotes an elastic member.

Claims (1)

(57) [Scope of request for utility model registration] And 1. A upper die held by the upper die base is down by a crank mechanism of the press mechanism, is retained in the lower mold base of the press machine structure, and a lower die for holding a resin-sealed semiconductor, wherein Held by the upper mold, the upper mold
A punch protruding from the lower die base, by lowering the upper die base, between the punch and the lower die, in a semiconductor crushing device that crushes the flash attached to the outer lead of the resin-encapsulated semiconductor, provided on one of said lower die and said upper die, and a stopper for restricting the lower limit position of the upper die to the other when burrs <br/> crush against the lower mold in contact, the upper die and the An elastic member provided on one side of the lower mold and having an elastic force capable of withstanding the crushing force of the burrs and elastically deforming so as to allow the upper mold base to descend after the stopper abuts ; semiconductor crushing apparatus comprising the.