JP2911246B2 - Lead bending method and lead bending device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lead bending method and a lead bending apparatus, and more particularly to a lead bending method and a lead bending apparatus for bending a lead into a J shape.

[0002]

2. Description of the Related Art Some semiconductor devices are manufactured by bending a lead into a J shape. Of these J-bent products, the most commonly used products are such that the tips of the leads 5 are held by the lower surface of the mold resin 6 as shown in FIG. As shown in FIG. 4 (b), some of the products have a shape in which the leads 5 are opened outward on the side surfaces of the mold resin 6 and the tips are held by the lower surface of the mold resin. There is. The product in which the lead is opened outward as described above has an effect that the lead can have a slight spring property.

[0003] A bending apparatus for bending a lead into a J shape like the above-described product is bent into a predetermined shape by performing bending processing several times. There are various bending methods, for example, the following method is used.
That is, in the first bending, the tip of the lead is bent into a round shape, in the second bending, the lead is bent to a position where the lead is inclined with respect to the resin base with the base of the lead as the fulcrum, and in the third bending, the lead is bent. On the other hand, the lead is bent to a right angle or more than a right angle, and is held on the lower surface of the resin mold portion while curling the lead tip in the fourth bending.

[0004]

In an actual lead bending apparatus, bending may be performed by a method different from the above method. However, in the final step of curling the lead, the lead is manufactured in advance according to the bending shape. The lead is pressed against the curling die thus formed to form a predetermined shape. FIG. 5A shows the state after the third bending, and FIG.
Is a state after curling, but a considerable sliding force acts on the lead during curling as shown in the figure. Here, in the case of a product in which the lead is curled while bending the lead inward, such as the product shown in FIG. 5, since the lead is angled inward in the same direction as the curling direction, a reaction force from the lead is generated when the curling process is performed. Even when it acts, it can be bent while maintaining the rigidity of the lead.

However, in a product in which the lead is formed to be open outward as shown in FIG. 4, when the lead is brought into contact with a curling die and a bending process is performed, a large reaction force of the lead appears and the rigidity of the lead cannot be maintained. In some cases, the leads are formed to bulge outward. As a result, there are problems that the molding angle varies between the left and right leads and that the curling shape is not constant. Therefore,
The present invention has been made to solve the above problems,
An object of the present invention is to provide a lead bending method and a lead bending apparatus capable of bending a lead with high accuracy when manufacturing a product having a J-shaped lead in which the lead needs to be formed to open outward. It is in.

[0006]

The present invention has the following arrangement to achieve the above object. That is, in a lead bending method of bending a lead into a J shape, when moving a product toward a curling die in order to curl the lead, the outer side surface of the lead located on the side surface of the resin mold portion is pressed from the outside. The curling die is bent into a predetermined shape by abutting the curling part of the lead on the curling die while maintaining the side shape of the lead. Also, in a lead bending device that bends a lead into a J shape, when curling the lead, the lower inner surface contacts the outer surface of the lead to hold the lead from the outside and rotate in the lead holding direction. A cam plate whose upper part is supported by a knockout is provided, and when the product is clamped by the knockout and the product moves toward a curling die, the cam plate guides the outer surface of the cam plate and rotates to guide the product. The curling die is provided with a stopper which is located at the holding position and which comes into contact with the cam plate from the outside at the position.

[0007]

[Function] In the curling process when bending a lead into a J-shape, the outer surface of the lead is held down while curling while holding the side surface of the lead, so that the lead opens outward during curling. And accurate bending can be performed. In the lead bending device, when the product is clamped by the knockout and moves to press the lead against the curling die, the cam plate moves together with the knockout, and the outer surface of the cam plate is guided by the stopper provided on the curling die. The outer surface of the lead is processed from the outside with the inner surface of the cam plate.

[0008]

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 an explanatory view showing the configuration of an embodiment of a lead bending apparatus to which the lead bending method according to the present invention is applied. This lead bending apparatus is a bending apparatus used in a bending step of curling a lead. In the figure, the left half of the center line shows the state before bending, and the right half shows the state during bending. The lead bending apparatus according to the present embodiment is characterized in that, when the product 10 is brought into contact with the curling die 12 and bent, the bending is performed while the inner surface of the cam plate 14 holds the outer surface of the lead 16.

In the lead bending apparatus, a cam plate 14 is attached to a knockout 22 supported by a suspension plate 20 by support pins 24 fixed in the front-rear direction. The support pins 24 are installed so as to penetrate the knockout 22 in the direction in which the leads are arranged, that is, in parallel with the side surfaces of the resin mold portion.
The cam plate 14 is rotatably supported on both sides of the knockout 22. 2 and 3 show a front view and a side view of the cam plate 14. FIG. The lower portion of the cam plate 14 is formed in a flat plate shape, and the upper portion protrudes from the flat plate portion in an L-shape as shown in FIG. 3 to form a support portion 14a, and an insertion hole for inserting the support pin 24 into the support portion 14a. 15 is provided. As described above, the two cam plates 14 are attached to face each other, but the support portion 14a through which the support pins 24 are inserted is bisected in the longitudinal direction of the support pins 24 by the opposed cam plates 14, and the facing cam plates 1
4 is rotatably attached to the support pin 24 by means of the contact. When the cam plate 14 is attached to the knockout 22, the upper surface of the cam plate 14 comes into contact with the step 25 of the knockout 22 to regulate the opening amount of the cam plate 14.

As shown in FIGS. 2 and 3, the cam plate 1
A thin pressing plate portion 14b is formed at the lower end side of 4. The pressing plate portion 14b presses the outer surface of the lead 16 of the product. Since the pressing plate portion 14b presses all the leads 16 at one time, the width of the pressing plate portion 14b is set to about the width of the product. At the center of the flat plate portion of the cam plate 14, a housing hole 26 for housing a spring 28 for opening the cam plate 14 outward is provided. As shown in FIG. 1, the ends of the springs 28 abut against the storage holes 26 of the cam plates 14, 14 facing each other, and the cam plates 14, 14 are resiliently reciprocated.

When the lead is bent, the knockout 22 descends toward the curling die 12, while the knockout 22 guides the outer surface of the knockout 22 to knockout 2.
A punch guide 32 that regulates the lowering position of 2, 2 is a stripper plate. Further, a knockout 34 for supporting the product 10 from the lower surface side is provided on the curling die 12 side, a curling portion 12 a for curling the lead 16 into a predetermined shape is provided on the curling die 12, and at the lower end of the cam plate 14. Stopper part 1 for regulating the position of the outer surface of the provided press contact plate part 14b
2b and a guide portion 12c for guiding the pressing plate portion 14b to enter. The guide portion 12c is formed by a tapered surface whose upper portion is opened outward.

Next, the operation of the lead bending apparatus of the above embodiment will be described. First, the product subjected to the lead bending in the previous process is transferred to the apparatus and set on the knockout 34 on the lower side. The lead 16 is set so as to extend below the resin mold portion as shown in the left half of FIG. The knockout 22 is guided by the punch guide 30 and descends from above, and clamps the product 10 between the lower surface of the knockout 22 and the knockout 34. In this state, the cam plates 14, 14 are opened outward by the resilience of the spring 28, and the inner wall of the recess 25 is
The upper surface of 4a serves as a stopper to contact and regulates the opening amount.

The product 10 is clamped by the knockout 22 and the knockout 34 while the curling die 12 is clamped.
Descend further towards. Accordingly, the cam plate 14 descends, and the lower end surface of the pressing plate portion 14b comes into contact with the guide portion 12c of the curling die 12. As the cam plate 14 descends, the pressing plate portion 14b descends along the tapered surface of the guide portion 12c, and the spring 28
The lower end of the cam plate 14 gradually narrows inward against the resilience of the cam plate 14, and the inner surface of the pressing plate portion 14b is
6 comes into contact with the outer surface and presses the lead 16 from outside.

When the pressing plate portion 14b descends past the guide portion 12c, the stopper portion 1 of the curling die 12 is lowered.
The outer surface is regulated by 2b and descends in a state where the outer surface is in sliding contact with the stopper portion 12b. The lead 16 is pressed against the curling die 12 by the knockout 22, so that the outer surface of the lead 16 is regulated by the inner surface of the pressing plate portion 14 b, and is bent into a predetermined curling shape by being pressed by the curling portion 12 a. You. FIG.
Is a state where the knockout 22 is lowered to the lowest position. The product 10 is pressed by the knockout 22 and the lead 1 is pressed by the pressing plate portion 14b.
6 is pressed and bent to form an outer surface. After the bending, the knock plate 22 is raised, whereby the cam plate 14 is pulled up above the curling die 12, and the pressing plate 14b is opened outward by the spring 28 to return to the state before the bending.

In the bending apparatus of this embodiment, as described above, when the lead 16 is curled,
Is bent while the outer surface of the lead is held down by the inner surface of the cam plate 14, so that the lead does not bulge outward due to the reaction force of the lead, and the lead can be bent at a constant angle without variation. . In the embodiment, the outer surface of the pressing plate portion 14b is
By making contact with the second stopper portion 12b, the pressing position of the pressing plate portion 14b is surely set so that accurate lead bending can be performed. In addition, when the pressing plate portion 14b holds the lead 16, the curling portion on the tip end side of the lead is opened, and after the outer surface of the lead 16 is pressed by the pressing plate portion 14b, the curling process is performed. It is possible to prevent the pressing plate portion 14 from rubbing the outer surface of the lead 16 during bending.

By curling the lead while pressing the lead from the outer surface with the cam plate,
Even if it is difficult to precisely form the lead due to its configuration, such as a product that is curled with the lead opened outward, it can perform lead bending without variation and perform stable bending. Can be. The lead bending apparatus of the embodiment is suitable for use in a product in which stable lead bending processing is difficult as described above. However, the lead bending device may be used for manufacturing a normal type J-bend product in which leads are inclined inward. It is valid. In these products, the outer side of the lead is curled while hitting the die, so the side of the lead may be damaged.However, if the outer side of the lead is curled with the cam plate as described above, the side of the lead will be damaged. It can be curled without attaching.
Since the bending apparatus of the above embodiment performs lead bending on the product in two opposing directions, in a product such as a quad type, the above-described curling process is performed twice on different sides to all the leads. Curling processing can be performed on this.

In the above embodiment, the knockout 22 is provided with the cam plate 14 so as to be rotatable so that the outer surface of the lead is curled while the knockout 22 is moved. The method of bending the sheet while holding it in a predetermined shape while holding the sheet from the outside is not limited to the above embodiment. It is also possible to provide a member for holding the outer side surface of the lead separately from the knockout, and to perform bending while maintaining the side surface shape of the lead.

[0018]

According to the lead bending method and the lead bending apparatus of the present invention, as described above, it is possible to reduce the variation in the forming dimension such as the bending angle of the lead, and to perform the accurate bending. And the lead can be bent without damaging the lead.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing the configuration and operation of a lead bending device.

FIG. 2 is a front view of a cam plate.

FIG. 3 is a side view of a cam plate.

FIG. 4 is an explanatory view showing a method of bending a lead.

FIG. 5 is an explanatory view showing another example of a lead bending method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Product 12 Curling die 12a Curling part 12b Stopper part 12c Guide part 14 Cam plate 14b Press-contact plate part 22 Knockout 24 Support pin 28 Spring 30 Punch guide 34 Knockout

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 23/50 B21D 5/01

Claims (2)

(57) [Claims] In a lead bending method for bending a lead into a J-shape, when a product is moved toward a curling die to curl the lead, the outer side surface of the lead located on the side surface of the resin mold portion is externally moved. A lead bending method, wherein a lead curl portion is brought into contact with the curling die to bend the lead into a predetermined shape while holding the side surface shape of the lead by pressing. 2. A lead bending apparatus for bending a lead into a J-shape. When the lead is curled, a lower inner surface abuts on an outer surface of the lead to hold the lead from the outside and a pressing direction of the lead. A cam plate whose upper portion is rotatably supported by a knockout is provided, and when the product is clamped by the knockout and the product moves toward a curling die, the outer surface of the cam plate is guided and rotated, A lead bending device, wherein the curling die is provided with a stopper which is located at a position for holding the lead and which abuts against the cam plate from the outside at the position.