JP3347886B2 - External lead bending equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external lead bending apparatus.

[0002]

2. Description of the Related Art In a resin-sealed semiconductor device, external leads are bent after resin sealing. FIG. 4 shows a conventional example of a bending apparatus used for bending an external lead. According to the conventional device shown in FIG. 4, first, the base of the external lead 18 of the semiconductor device 16 is sandwiched between the fixed die 50 and the knockout 52, and the tip of the external lead 18 is held in a free state. Next, the bending lead 54 is placed on the external lead 1 from above.
8 and pressed against the fixed die 50 to bend into a predetermined shape. In this bending process, the external lead 18 is formed by the operation of the bending punch 54 and the shape of the fixed die 50.

In this conventional apparatus, in order to minimize the slippage between the external lead 18, the bending punch 54 and the fixed die 50 so as not to damage the plating applied to the surface of the external lead, as shown in FIG. Is moved along the arrow while rotating. The bending punch 5
By modifying the track of No. 4, plating can be protected, and the quality of the semiconductor device 16 can be improved, the service life of the working tool can be extended, and maintenance can be facilitated.

Recently, the number of pins of the semiconductor device 16 has been increased and the external leads 18 have been miniaturized. Therefore, it is necessary to bend the external leads 18 with high precision in order to mount the semiconductor device 16 on a substrate. But,
In the above-described conventional device, when the external lead 18 is bent, the tip of the external lead 18 is always in a free state, and the external lead 18 is twisted by bending due to a variation in the cross-sectional shape of the external lead 18. Etc. are likely to occur.

On the other hand, the conventional device of FIG. 5 is configured as a device capable of preventing the external lead 18 from being twisted or the like. After the base of the external lead 18 is sandwiched between the fixed die 51 and the knockout 52, When the bending of the external lead 18 is started, the distal end side of the external lead 18 is clamped between the bending punch 56 and the movable die 58, and the external lead 18 is bent by moving an arc trajectory in the clamped state. In the case of this device, since the tip of the external lead 18 is pinched and forcibly bent, it is possible to preferably prevent the external lead 18 from being twisted.

[0006]

However, in the case of the above-described apparatus in which the external lead 18 is clamped and bent by the above-described apparatus, an indentation when the external lead 18 is clamped by the bending punch 56 and the movable die 58 is generated. 18 remains,
There is a problem that the appearance of the product is affected. Further, in the conventional bending process, the external lead 18 is set at 4 at the base position.
There is a problem that it is difficult to bend accurately to an acute angle of 5 ° or less. The present invention has been made to solve these problems, and an object of the present invention is to prevent the occurrence of torsion or the like of an external lead and to bend it with high accuracy, and to leave an impression on the external lead of a product. An object of the present invention is to provide an external lead bending apparatus which can perform bending without any bending.

[0007]

The present invention has the following arrangement to achieve the above object. That is, by moving the movable die toward and away from the fixed die, an external lead of the semiconductor device after resin sealing is bent and fixed to the fixed die in an external lead bending device that bends into a substantially Z shape. A fixed bending die that abuts against a root of the external lead and supports the semiconductor device; and a movable die that is opposed to the fixed bending die and is resiliently supported in the direction of the fixed bending die to support the semiconductor device. A knockout that clamps a portion between the fixed bending die and a contact surface that is positioned on a side of the knockout and that is rotatably supported in a direction of coming and coming from a side wall of the semiconductor device and abutting on an external lead. A curved contact portion having a rounded side surface at a corner portion for holding the base side of the external lead, a clamp portion having a flat clamp surface on the side for holding the distal end side of the external lead, and the clamp. A bending punch provided with a dug for forming a clearance space between the bending portion and the bending contact portion, and bending when the bending punch approaches an external lead during bending. A cam mechanism for restricting the moving direction by rotating the tip of the punch in a direction approaching the side wall direction of the semiconductor device, and a bending die holder which is supported by the fixed mold by being resiliently supported in the movable mold direction. A tip end side of the fixed bending die is rotatably supported in a direction facing the bending punch so as to be in contact with and away from a side wall of the semiconductor device. A contact portion is provided, and when the tip of the bending punch contacts the external lead, the tip sandwiches the external lead with the tip of the bending punch, and the movable die approaches the fixed die. When further moved, the bending punch and The distal end side is characterized by comprising a bending die rotates in direction of the side wall of said semiconductor chip sealing portion.
Further, the clamping position of the external lead by the clamp portion of the bending punch and the contact portion of the bending die is set to a position ahead of a separating position at which the external lead is separated in a later process. Further, the cam mechanism is constituted by a roller provided on the bending punch, and a cam provided with an inclined surface with which the roller comes into contact and arranged on the side of the bending punch. Further, the cam mechanism is constituted by a cam surface provided on an outer surface of the knockout, and a roller which rides on the cam surface and rotates the bending punch when the bending punch moves in a direction approaching a bending die. It is characterized by the following.

[0008]

According to the bending device for an external lead of the present invention, by moving the movable die close to the fixed die, the root of the external lead of the semiconductor device is clamped between the fixed bending die and the knockout. Is further approached to the fixed mold, whereby the distal end of the external lead is clamped by the clamp portion of the bending punch and the contact portion of the bending die. Then, as the movable mold approaches the fixed mold, the bending punch and the bending die are rotated toward the side wall of the semiconductor device while clamping the external leads by the cam mechanism, and the bending contact portion of the bending punch is set as the bending position. The external lead is bent into a substantially Z shape. The external lead is clamped between the clamp part of the bending punch and the contact part of the bending die, and the bending contact part is bent at the bending position. it can.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a sectional view showing an embodiment of an external lead bending apparatus according to the present invention, and FIG.
It is explanatory drawing explaining operation | movement of the bending punch and bending die of Example. Reference numeral 10 denotes a fixed type, which is fixed to the base of the apparatus main body. A movable mold 12 is provided to be movable toward and away from the fixed mold 10. In the present embodiment, the fixed mold 10 is fixed below and the movable mold 12 is arranged above. However, if the movable mold 12 can move toward and away from the fixed mold 10, the position of the movable mold 12 can be adjusted. The relationship can be set arbitrarily.

Reference numeral 14 denotes a fixed bending die, which is provided fixed to the fixed die 10. A concave portion for receiving the semiconductor device 16 is provided on the upper surface of the fixed bending die 14, and the root of the external lead 18 of the semiconductor device 16 received in the concave portion contacts the upper surface of the outer periphery of the concave portion. Reference numeral 20 denotes a knockout, which is attached to the movable die 12 so as to face the fixed bending die 14. A spring 22 is resiliently provided on the back surface of the knockout 20, and the knockout 20 is movably supported by the movable mold 12. This knockout 20
By moving up and down within a predetermined range together with the movable mold 12 and lowering to the position shown in FIG. 1, the lower surface of the outer shell of the recessed portion abuts against the base of the external lead 18 of the semiconductor device 16 and the fixed bending die 14, the external lead 18 is sandwiched.

Reference numeral 24 denotes a bending punch, which is a knockout 2
The movable mold 12 is supported by the movable mold 12 at its base so as to be rotatable about a shaft 25 in a direction in which the tip side comes into contact with and separates from the side wall of the resin sealing portion 16a. As shown in FIG.
The contact surface of the bending punch 24 that contacts the external lead 18 is provided with a bending contact portion 24a having a rounded side surface shape at an inner corner thereof. This bending contact portion 24
In the case of a, the corner angle is formed to be an acute angle rather than a right angle by forming a dug in the center of the contact surface. 24
b is a clamp portion formed on a flat surface following the dug portion. The clamping surface of the clamping portion 24b and the bending contact portion 24
a is set so as to be at the same height position when the external lead 18 is bent and formed.
An escape space is formed in the middle portion 4a by dug-in.

Reference numeral 24c denotes a roller rotatably mounted on the outer surface of the bending punch 24. The roller 24c is provided to regulate the moving direction of the bending punch 24 when it descends, and is provided so as to abut on the inclined surface of the cam 27 provided on the side of the bending punch 24. The cam 27 is formed on an inclined surface having a high outer side and a lower level toward the fixed bending die 14 and the knockout 20, and serves to rotate the bending punch 24 inward when the bending punch 24 descends.
The cam 27 and the roller 24c constitute a cam mechanism together with a support mechanism for rotatingly supporting the bending punch 24. These cam mechanisms define the bending angle of the external lead 18 and set the inclined surface and its arrangement in accordance with a predetermined bending shape of the external lead 18. The bending punch 24 is urged by a restricting spring 26 in a direction in which the distal end side opens outward, and is regulated by a stopper 28 protruding from the movable die 12 so as not to rotate outward by a predetermined angle or more.

Reference numeral 30 denotes a bending die holder, which has a mounting portion 30a for mounting the fixed bending die 14 at the upper portion, and a piston 30c at the lower portion via a rod 30b. The piston 30c is provided in the fixed die 10. Cylinder 32
Is fitted inside. An upper part of the cylinder 32 communicates with a piston lowering air path 36, and a lower part of the cylinder 32 communicates with a piston raising air path 38. Compressed air is introduced into the cylinder 32 via these air paths, and the bending die holder 30 (the piston 30
(via c). As a result, the bending die holder 30 is supported by the fixed mold 10 so as to be immersed in the fixed mold 10. In addition,
The packing 31 is a ring-shaped hermetic member that is mounted in a groove provided on the outer peripheral surface of the piston 30c and is provided in contact with the inner peripheral surface of the cylinder 32 to be hermetically sealed. Further, the cushion 34 is mounted in a groove formed in a ring shape on the upper end surface and the lower end surface in the cylinder 32, and can cushion the operation of the piston 30c.

Reference numeral 40 denotes a bending die, which is bent by a shaft 41 on the side of the fixed bending die 14 facing the bending punch 24 so as to be rotatable in a direction in which the tip side comes into contact with and separates from the side wall of the resin sealing portion 16a. It is supported by the die holder 30. Bending die 4
The abutting portion 40a that abuts on the external lead 18 is provided in the shape of a mountain-shaped protrusion having a high position facing the clamp portion 24b provided on the bending punch 24, and gradually lowers inward from the abutting portion 40a. It is formed on the inclined surface which becomes as follows. As a result, the clamp portion 24b of the bending punch 24 is
8 and the contact portion of the bending die 40 and the clamp portion 2
The external lead 18 is sandwiched between the external lead 4b.

Next, the operation of the above embodiment will be described. First, the semiconductor device 16 is set on the fixed bending die 14 and the movable die 12 is lowered, whereby the root of the external lead 18 of the semiconductor device 16 is held between the fixed bending die 14 and the knockout 20. As the movable mold 12 descends, the roller 24c attached to the bending punch 24
7, and the bending punch 24 starts to gradually rotate inward from the open position. The left half of FIG. 1 shows a state in which the bending punch 24 starts to rotate inward from the open position. At this time, the bending die 40 is also in the open position, and the tip of the bending die 40 is in contact with the lower surface of the external lead 18.

The movable die 12 further descends and the bending punch 2
When the clamp portion 24b of FIG. 4 contacts the upper surface of the external lead 18, the clamp portion 24b and the contact portion 40a of the bending die 40
The external lead 18 is sandwiched between these. FIG. 2 shows a state where the external lead 18 is sandwiched by imaginary lines. Bending punch 24
The bending die 40 is characterized in that it clamps only the tip of the external lead 18 and prevents the punch from coming into contact with the external lead 18 from the clamping position to the base side of the external lead 18. At this time, the bending contact part 2 of the bending punch 24
4a is in contact with the upper surface of the external lead 18.

In this state, the movable mold 12 further descends,
The external lead 18 is formed by bending. The external lead 18 is pushed down while being sandwiched between the bending punch 24 and the bending die 40, the movement direction of the bending punch 24 is regulated by the cam 27, and the bending punch 24 and the bending die 40 are connected to the semiconductor device 1.
6 is formed in a Z-shape by rotating toward the side wall direction. The solid line part in FIG. 2 and the right half part in FIG. 1 show a state in which the external lead 18 is bent and formed. The bending punch 24 is formed so as to press the external lead 18 while abutting the bending contact portion 24 c on the upper surface of the external lead 18.

In this bending, the bending punch 24 and the bending die 40 clamp only the distal end of the external lead 18. However, since the bending contact portion 24 a is bent at the bending position of the external lead 18, the bending is performed. Even if the external lead 18 is not pressed by the entire contact surface, the external lead 18 can be reliably bent without causing twisting or the like. In addition, the bending contact portion 24a contacting the external lead 18 may be formed in a round shape so that the plating covering the external lead 18 is not damaged. Further, since the bending contact portion 24a is formed at an acute angle, the bending accuracy of the external lead 18 can be improved, and the external lead 18 can be improved compared to the case where a punch formed on a flat surface is simply used.
Can be bent at an acute angle.

In order to bend accurately with this lead bending apparatus, it is necessary to appropriately set the clamping force when the external lead 18 is clamped by the bending punch 24 and the bending die 40. Since the external lead 18 is clamped by the pressing force of the pressing device that presses the movable die 12 downward and the pressing force of the compressed air that urges the bending die holder 30 upward, the pressing force is set to a predetermined value or more. This makes it possible to prevent the bending punch 24 and the bending die 40 from slipping during the bending process.
By appropriately setting the supporting force of the support 8, the external lead 18 can be bent with high accuracy.

In the case of the external lead bending apparatus according to the present invention, since the distal end of the external lead 18 is pinched and bent as described above, the portion holding the external lead 18 is not used after being cut off by post-processing. In this case, no indentation appears on the product at all, and it is possible to perform a bending process that is suitable in terms of protection of the plated surface and appearance.

The roller 24c and the cam 2 of the above embodiment
7, a cam mechanism as shown in FIG. 3 may be employed. This cam mechanism has a cam surface 20a provided on the outer surface of the knockout 20, and a roller 2 provided on the upper inner surface of the bending punch 24 when the bending punch 24 descends.
4c is configured to move while being in contact with the cam surface 20a. As the bending punch 24 descends and the roller 24c rides on the cam surface 20a, the shaft 2
By bending the bending punch 24 about 4d and moving the lower end of the bending punch 24 in a direction approaching the knockout 20, the same bending as in the above embodiment is performed.

In these embodiments, the shapes of the bending punch 24 and the bending die 40 are changed according to the difference in the bending shape and the bending angle of the external lead 18, or each of the bending punch 24 and the bending die 40 is formed as a movable die. It goes without saying that the position of the shaft that is rotatably supported by the bending die holder 30 can be changed, and the installation positions of the bending punch and the cam can be appropriately changed. The external lead bending apparatus according to the present invention can be applied to processing of various types of semiconductor devices such as a quad type.

[0023]

According to the external lead bending apparatus of the present invention,
As described above, since the external lead is sandwiched between the bending punch and the bending die, and the external lead is bent with the bending contact portion as the bending position, the bending can be performed while preventing the occurrence of twisting or the like. Also, since only the tip of the external lead is clamped between the clamp part of the bending punch and the contact part of the bending die, bending is performed.
Bending can be performed without causing indentation on the external lead and without damaging the plating film provided on the external lead.
In addition, by bending the external lead with the bending contact portion as the bending position, it is possible to achieve a sharp effect with high accuracy and sharpness.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an external lead bending apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing an operation of a main part of the embodiment of FIG. 1;

FIG. 3 is an explanatory view showing another embodiment of an external lead bending apparatus.

FIG. 4 is an explanatory diagram showing a conventional technique.

FIG. 5 is an explanatory diagram showing another conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Fixed type 12 Movable type 14 Fixed bending die 16 Semiconductor device 16a Resin sealing part 18 External lead 20 Knockout 24 Bending punch 24a Bending contact part 24b Clamp part 24c Roller 27 Cam 30 Bending die holder 40 Bending die

Claims (4)

(57) [Claims] 1. An external lead bending device for bending an external lead of a semiconductor device into a substantially Z shape after resin sealing by moving a movable die toward and away from a fixed die. A fixed bending die provided to abut on a root portion of the external lead to support the semiconductor device; and a movable die resiliently supported in a direction of the fixed bending die in opposition to the fixed bending die. A knockout for holding the root of the lead between the fixed bending die and a side of the knockout, rotatably supported in a direction approaching and separating from a side wall of the semiconductor device, and abutting on an external lead; A curved contact portion having a rounded side surface shape at a corner portion for holding the base side of the external lead on the contact surface, and a clamp portion having a flat clamp surface formed on the side for holding the distal end side of the external lead, and A bending punch provided with an undercut for forming a clearance space between a clamp portion and the bending contact portion; and bending when the bending punch approaches an external lead during bending. A cam mechanism for regulating the moving direction by rotating the tip of the punch in a direction approaching the side wall direction of the semiconductor device; and a bending die holder which is resiliently supported in the movable mold direction in the fixed mold. A tip end side of the fixed bending die is rotatably supported in a direction facing the bending punch so as to be in contact with and away from a side wall of the semiconductor device. A contact portion is provided, and when the tip of the bending punch contacts the external lead, the tip sandwiches the external lead with the tip of the bending punch, and the movable die approaches the fixed die. When further moved to External lead bending device, characterized in that the distal end side with blood; and a bending die rotates in direction of the side wall of said semiconductor chip sealing portion. 2. The method according to claim 1, wherein a clamping position of the external lead between the clamp portion of the bending punch and the contact portion of the bending die is set to a position ahead of a separation position at which the external lead is separated in a later process. 2. The external lead bending apparatus according to claim 1. 3. The cam mechanism comprises a roller provided on the bending punch, and a cam provided with an inclined surface with which the roller abuts and arranged on the side of the bending punch. 2. The external lead bending apparatus according to claim 1. 4. A cam surface provided on the outer surface of the knockout by the cam mechanism, and a roller which rides on the cam surface and rotates the bending punch when the bending punch moves in a direction approaching a bending die. The bending device for an external lead according to claim 1, wherein the bending device is configured.