JPH0531533A - Method and device for bending lead - Google Patents

Abstract

PURPOSE:To accurately bend a lead without scratching the surface of the lead. CONSTITUTION:In a method for bending lead that the lead 12 is bent into a specified shape using a die 16 and punch 18, when the lead 12 is clamped and bent with the aforementioned die 16 and punch 18, bending is executed by interposing protective films 30, 32 with which the lead 12 is prevented from rubbing and which are separately provided from the punch 18 or die 16 between pressing contact surfaces where the punch 18 is brought into contact with the lead 12 or the die 16 is brought into contact with the lead 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead bending method for IC products and the like.

[0002]

2. Description of the Related Art There are various lead shapes of IC products such as a gull wing type and a J bend type. These products are manufactured by bending leads into a predetermined shape by a lead bending device. In the lead bending apparatus, the work piece is positioned and set on the die, and the lead is punched to form the work piece. By the way, in recent IC products, in order to omit the step of solder dipping after bending and forming the leads, products in which the outer leads are previously solder-plated for mounting have been used at the lead frame stage. When processing a product with solder plating on such a lead, the lead is rubbed by a punch and a die when the lead is bent and the solder plating peels off, or the peeled solder is peeled off when molding other products. There is a problem in that it adheres to the leads and causes a short circuit between the leads.

Therefore, even in the conventional lead bending apparatus, sector leads are used to press the leads sideways in the gull wing type bend forming, and punch rollers are used in the J bend type bend forming. Bending is performed so that the rubbing of the leads is reduced.

[0004]

However, although the rubbing of the lead surface can be reduced to some extent by the method of sector bending or the method of using the punch roller as described above, these conventional methods prevent the rubbing of the lead surface. The effect is limited. Therefore, the present invention has been made to solve these problems, and an object of the present invention is to cause rubbing on the surface of a lead when the lead of an IC product that has been solder-plated in advance is bent. It is an object of the present invention to provide a lead bending method and a lead bending apparatus that can perform accurate bend forming without a lead bending process.

[0005]

The present invention has the following constitution in order to achieve the above object. That is, in a lead bending method of bending a lead into a predetermined shape by using a die and a punch, when the lead is clamped by the die and the punch to bend the lead, the punch and the lead are brought into contact with each other between a pressing surface or a die. The bending process is performed by interposing a protective film, which is formed separately from the punch or the die, between the pressing surfaces with which the and the leads come into contact with each other to prevent rubbing of the leads. Further, in a lead bending apparatus for bending a lead into a predetermined shape by using a die and a punch, when the lead is clamped and bent by the die and the punch, the punch and the lead come into contact with each other between a pressing surface or a die. It is characterized in that a protective film, which is interposed between the pressing surfaces with which the leads come into contact with each other and prevents rubbing of the leads, is arranged at an intermediate position between the punch and the die.

[0006]

[Function] A lead is processed by contacting the punch or the die with the protective film without direct contact of the die or the punch with the lead by bending the lead by interposing the protective film between the die or the punch and the lead. Therefore, it can be bent without causing lead rubbing.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is an explanatory view showing an embodiment of a lead bending apparatus according to the present invention. The embodiment shows a gull wing type sector bending device. 10 in the figure
Is a work piece, and 12 is a lead. 14 is a knockout provided on the upper die, and 16 is a die. Reference numeral 18 is a sector punch for bending the lead 12 with the die 16. The sector punch 18 is rotatably supported by the upper die 20 by a shaft 22. A roller 24 is provided on the inner surface of the upper portion of the sector punch 18, and a cam surface 26 with which the roller 24 abuts is provided on the outer surface of the knockout 14.

When bending the leads, after supporting the workpiece 10 by the knockout 14, the sector punch 18 descends as the upper die 20 descends.
The roller 24 of No. 8 climbs up to the cam surface 26 and bends while pressing the pressing surface of the sector punch 18 slightly inward. The operation of the sector punch 18 and the like is similar to that of the conventional example.

The lead bending apparatus of the present embodiment is characterized in that protective films 30 and 32 are attached to a conventional processing machine as shown in FIG. The protective films 30 and 32 are interposed between the die 16 and the sector punch 18 during the lead bending process to sandwich the leads 12 of the workpiece 10 between the upper and lower surfaces, and the solder plating of the leads 12 causes the die 16 and the sector punch 1 to be soldered.
The purpose is to prevent them from adhering to No. 8. Therefore, the protective films 30 and 32 are formed of a material to which solder plating is hard to adhere. For example, a titanium-coated stainless film, a ceramic tape or the like can be used. Further, since the protective films 30 and 32 are sandwiched between the die 16 and the sector punch 18 to bend the lead 12, it is necessary to have flexibility and a certain durability.

As shown in FIG. 1, the protective film 30 installed on the side of the sector punch 18 is clamped and supported on the inner bottom surface of the knockout 14 by screwing one end side with a film support plate 34, and laterally from the knockout 14. The film is pulled out, hung on the support roller 36, and the other end is directed upward, and connected to the arm 40 via the spring 38. The arm 40 extends laterally from the top of the knockout 14, and the protective film 30 is connected to the arm 40 via a spring 38 to hold the film in a tensioned state. The supporting roller 36 is provided for laterally pulling out and holding the protective film 30.
Like 0, it is supported by the knockout 14 and moves up and down with the knockout 14.

The protective film 32 installed on the die 16 side of the lower die supports the film support plate 42 with screws on the inner bottom surface of the receiving portion of the die 16 that supports the workpiece 10, and at the same time, the die 16 side. After pulling it out toward the support roller 44, the other end is connected downward to the base of the die via a spring 46. The protective film 32 is also a spring 46.
Is elastically supported by the die 16 and the support roller 44 in a stretched state, and can be expanded and contracted. The width of the protective films 30 and 32 is set so that the entire lead 12 can be covered when the lead 12 is bent. Similarly, the film support plate 42 is screwed and supported, and the other ends of the die 16 are pulled out to both sides, are locked to the bearings 44, and are elastically fixed to the lower mold via the springs 46. When not processed, the protective film 32 is protected by the elastic force of the spring 46.
It is supported in a stretched state between the lead forming part and the bearing 44.

Next, a method of bending the leads using the lead bending apparatus of the above embodiment will be described. First, after setting the workpiece 10 at a predetermined position of the die 16, the upper die 20 is lowered and the knockout 14 is moved to the workpiece 1.
The 0 lead 12 is pressed against the die 16 at the base position to support the workpiece 10. At this time, the workpiece 10 is pressed and supported through the protective films 30 and 32 because the protective films 30 and 32 are interposed between the knockout 14 and the die 16.

With the knockout 14 supporting the workpiece 10, the upper die 20 is further lowered, and along with this, the sector punch 18 is lowered to lead the lead 1 to and from the die 16.
2 is pierced and bent into a predetermined shape. As described above, the sector punches 18 and 18 are formed by bending so that the roller 24 rides on the cam surface 26 and presses the punches inward. Even when the bending is performed by the sector punches 18, 18, the protective films 30 and 32 are interposed in between, so that the lead 12 is bent and formed with the protective films 30 and 32 interposed therebetween. In the state before bending, the protective films 30 and 32 are held in a state of being stretched by the springs 38 and 46, but when the sector punch 18 descends, the pressing force of the sector punch 18 pulls the protective film 30 and the leads 12 Is bent and the protective film 32 is also drawn to follow the shape of the die 16, so that the protective film 3 is attached to the upper and lower surfaces of the lead 12.
Bending is performed with 0 and 32 pressed. After bending the leads, the upper die 20 is moved up to its original position to release the pressing of the protective film 30 by the sector punch 18, and the elastic force of the spring 38 stretches the protective leads 30 to the left and right as shown in FIG. Then, the state returns to the state in which the next workpiece 10 is set and the state in which the next workpiece 10 is set is returned.

FIG. 2 shows a state in which the sector punch 18 is lowered to the bottom dead center position and the leads 12 are bent and formed. A protective film 30 and a protective film 32 are sandwiched between the upper and lower surfaces of the lead 12 and bent. As described above, in the bending apparatus of this embodiment, since the protective films 30 and 32 are sandwiched between the upper and lower surfaces of the lead 12, the die 16 and the sector punch 18 are bend-formed without directly contacting the lead 12, Bending can be performed without attaching the solder plating applied to the leads 12 to the die 16 or the sector punch 18. Also, the sector punch 18,
The die 16 is rubbed between the protective films 30 and 32, and the rub between the sector punch 18 and the die 16 and the lead 12 is prevented, so that the problem of peeling of the solder plating can be avoided. Protective film 30, 32
Since a film to which solder plating is difficult to adhere is used for the lead bending process with high accuracy, the quality of the product can be improved. Further, when solder plating adheres to the protective films 30 and 32 and becomes dirty, or when the protective films 30 and 32 deteriorate, only the protective films 30 and 32 can be exchanged and used, so maintenance of the apparatus is extremely easy. It can be done easily.

The above embodiment is an example of sector bending using the sector punch 18, but the method of bending the protective film by sandwiching it between the lead bending forming surfaces is different from other lead bending processing methods. Can be similarly applied. FIG. 3 shows an example in which the lead 12 is applied to a J-bending processing apparatus. In the J bending process, the tip of the lead 12 is curled. In this bending device, the punch roller 50 is provided in the roller holder 48 and the punch roller 50 is provided.
Thus, the lead 12 is pressed against the die 16 to be bent. In this case as well, the protective film 30, 32 leads 1
By bending the upper and lower surfaces of the lead 2 to form the lead 1
Bending can be performed without directly contacting the punch roller 50 and the bending surface of the die 16 with the surface 2. As a result, it is possible to avoid a problem at the time of bending by solder plating provided on the lead 12. This makes it possible to improve the quality of IC products.

Although the upper and lower surfaces of the lead 12 are both covered with the protective film in the above embodiment, the protective film may be provided only on one surface of the lead 12 which requires surface accuracy in some cases. But of course it doesn't matter. Further, in the above embodiment, the arm 40 is attached to the knockout 14 of the protective film 30 so that the protective film 30 moves together with the knockout 14, but the method of disposing the protective film 30 is also limited to the above method. Instead, they can be appropriately arranged according to each lead bending apparatus.

[0017]

As described above, according to the lead bending method and the lead bending apparatus of the present invention, the lead can be bent without bending when forming the lead with high accuracy. It will be possible to manufacture high quality products. Further, when a product plated with solder is bent, the solder does not adhere to the die or the punch, so that the maintenance of the device is facilitated and so on.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a lead bending device.

FIG. 2 is an explanatory diagram showing a lead bending state of a workpiece.

FIG. 3 is an explanatory view showing an embodiment of another bending apparatus to which the lead bending method is applied.

[Explanation of symbols]

10 Workpiece 12 leads 14 Knockout 16 dies 18 sector punch 20 Upper mold 24 roller 26 Cam surface 30, 32 Protective film 36,44 Support roller 50 punch rollers

Claims (2)

[Claims] 1. A lead bending method for bending a lead into a predetermined shape using a die and a punch, wherein a pressing surface with which the punch and the lead come into contact when the lead is clamped and bent by the die and the punch. A lead bending method, characterized by interposing a protective film, which is formed separately from a punch or a die, between the pressing surfaces where the die and the leads come into contact with each other, and which protects the leads from rubbing. 2. A lead bending apparatus for bending a lead into a predetermined shape by using a die and a punch, wherein between a pressing surface where the punch and the lead come into contact when the lead is pressed by the die and the punch to bend. Alternatively, the lead bending apparatus is characterized in that a protective film, which is interposed between a pressing surface where the die and the lead come into contact with each other and prevents rubbing of the lead, is arranged at an intermediate position between the punch and the die.