JPH06344396A - Side burr removing mechanism of lead frame - Google Patents

Abstract

PURPOSE:To certainly remove the side burr of a lead frame without deforming the frame by providing a punch pushing off the side burr of the lead frame to the upper mold of a processing apparatus applying the bending processing of a lead while forwardly sending the lead frame after the molding of a resin. CONSTITUTION:A side burr removing mechanism is constituted so as to remove side burr 22 in matching relation to the feed operation of a lead frame at the time of the processing of the lead frame and arranged on the side edge side to which the side burr is bonded of the lead frame. A punch 14 letting the side burr fall downwardly is attached to the punch plate 12 arranged on the upper mold of a processing mold. The punch 14 falls simultaneously with the falling of the upper mold to push off the side burr 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a side burr removing mechanism for a lead frame after resin molding.

[0002]

2. Description of the Related Art A lead frame on which a semiconductor chip is mounted is resin-molded and then transferred to processing steps such as resin removal and dam bar cutting. By the way, when the lead frame is resin-molded, the runner path extending from the pot crosses one side edge of the lead frame and communicates with the cavity on the lead frame for resin filling. Since there is a slight gap between the side edge of the lead frame and the side wall of the housing recess of the lead frame of the molding die, the molten resin flows into this gap when the resin is filled and hardens to form side burrs. Become.

The side burr adheres to and remains on the side edge portion of the lead frame by the thickness of the lead frame. However, the side burr may drop into the mold during the processing step and cause damage to the mold. Therefore, in order to prevent the side burrs from sticking to and remaining for a long time, it is possible to stop the resin that has flowed out by providing a resin pool on both sides of the side wall portion of the molding die through which the runner path passes. There is.

Since the side burr damages the mold as described above, the side burr is removed after the resin molding. FIG. 6 shows a conventional structure in which a side burr cutter for removing a side burr is provided in a processing device for processing a lead frame after resin molding. In the figure, 5 is a roller that comes into contact with the side edge of the lead frame, 6 is a movable arm that supports the roller 5, and 7 is a cylinder that pushes the movable arm 6.

In this example, the lead frame is transferred from the right side of the drawing to the left side and processed, and the side burr adheres to the left side in the traveling direction. 8 is a cutter for removing side burrs, which is arranged on the side where the side burrs adhere. Cutter 8
Has a blade for abutting the side edge of the lead frame to scrape off the burr. The lead frame inserts the feed pin into the guide hole according to the machining operation of the equipment and feeds the pitch, but the side varicutter operates according to the feeding operation of this lead frame, and when the lead frame is fed and moved, the cylinder The roller 7 is driven to abut the side edge of the lead frame, and the side edge of the lead frame to which the side burr adheres is pressed against the cutter 8, and the side burr is scraped off.

[0006]

In the above side burr cutter, when the lead frame is pitch-fed by the feed pin, the cutter 8 is pressed against the side edge of the lead frame to scrape off the side burr. In this case, the feed pin is guided. Since the lead frame is pressed against the cutter 8 when the lead frame is inserted into the hole and is being conveyed, it may cause deformation of the guide hole of the lead frame or burring. Further, since the cutter 8 contacts the side edge of the lead frame during the progressive feeding of the lead frame, there is a problem in that the side edge portion where the side burr is not adhered is also rubbed, which may deform the lead frame.

The guide hole of the lead frame has an important action for accurately positioning the lead frame and performing high-precision processing, and if deformation occurs during processing, it will be great in terms of processing accuracy of the product. It becomes a problem. Therefore, the present invention has been made to solve these problems, and an object of the present invention is to easily and surely remove side burrs attached to a lead frame after resin molding without deforming the lead frame. It is intended to provide a lead frame side burr removal mechanism that can be removed.

[0008]

The present invention has the following constitution in order to achieve the above object. That is, a side burr removing mechanism of a lead frame for partially adhering and remaining side burr on a predetermined portion where the runner path has passed on the side edge of the lead frame after resin molding, wherein the lead after the resin molding is performed. The lead frame is located above the side burrs at the lead frame feed position in the upper die of a processing device that performs required processing such as bending of the lead while sequentially feeding the lead frame to the frame, and pushes the upper die to move the lead frame. It is characterized in that a punch for removing the side burrs is provided. Further, the punch abutment portion that abuts against the side burr and removes the side burr to be removed is formed in a tapered surface, and the abutment part is positioned above the side burr attachment position before the side burr is ejected. It is characterized by setting.

[0009]

Operation: The lead frame is subjected to the required processing while being progressively fed by the processing die, but when the side burr of the lead frame is transferred to the punch position of the side burr removal mechanism, the punch is lowered by the pushing operation of the upper die. , The side burrs adhering to the side edges of the lead frame are scraped off and removed. By forming the abutting portion of the punch into a tapered surface, the abutting portion of the punch escapes to the outside when the punch abuts against the side edge of the lead frame, and the side burr is scraped off to remove the burr.

[0010]

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 shows an example of a processing apparatus provided with a side burr removing mechanism for a lead frame according to the present invention. In the figure, 10 is a processing die for processing the lead frame after resin molding. The processing die 10 is provided with a processing stage for performing required processing on the lead frame, and the portion A in the drawing shows a portion where the lead frame is sequentially fed to each processing stage and moves. The lead frame is sequentially fed from the left side to the right side of the drawing to be processed, and the side burr is attached to the left side edge of the lead frame in the traveling direction.

The portion B shows the position of the side burr removing mechanism. The side burr removing mechanism is arranged on one side edge of the lead frame to which the side burr is attached. In the embodiment, a side burr removing mechanism is provided on the upper die of the working die. FIG. 2 shows an enlarged side burr removal mechanism. In the figure, 12 is a punch plate installed in the upper die of the working die, and 14 is a punch for side burr removal, which is attached downward to the punch plate 12. The punch 14 removes the burr attached to the side edge of the lead frame at its lower end surface.

The punch 14 has a fulcrum pin 1 provided on the upper portion thereof.
6 rotatably supports the punch plate 12 in the vertical plane, and the spring 1 is attached to the outer surface of the punch 14.
Interpose 8. The spring 18 is a spring that urges the lower end side of the punch 14 in a direction of pressing the side edge of the lead frame. The spring 18 is intended to return the punch 14 to the initial position, and the elastic force is not set to be strong.

The side burr removing mechanism of this embodiment removes the side burr in accordance with the lead frame carrying operation when the lead frame is processed. The side burr is scraped off by the punch 14 every time the lead frame is sequentially fed. Remove. 3 and 4 show how the punch 14 removes the side burr. The punch 14 acts as the upper die lowers and lowers to push down the side burr. FIG. 3 shows a state before the side burr is removed by the punch 14 and the punch 14 is in the upper position.

In the initial state where the punch 14 is in the upper position, the punch 14 is set such that the inner side surface position thereof is slightly inside the side edge position of the lead frame 20. This is for punching when the side burr 22 is removed by the punch 14.
This is for ensuring that the lower end surface of the abuts against the side burr 22 and can be deleted. Punch 1 for lead frame 20
4 is in the upper position, pitch feed is performed by the feed pin, and stops when the side burr 22 comes under the punch 14.

Next, as the upper die descends, the punch 1
4, the side burrs 22 attached to the side edges of the lead frame 20 are scraped off and removed as shown in FIG. The inner surface of the punch 14 that contacts the lead frame 20 has a tapered contact surface 14a as shown in the figure.
And the contact portion 14a when the punch 14 is pushed down.
The part is formed so as to contact the side edge of the lead frame 20. When the punch 14 is pushed down and the abutting portion 14a comes into contact with the side edge of the lead frame 20, the lower end side of the punch 14 escapes slightly outward as shown in FIG. 4, and the side burr 22 is scraped off at the abutting portion 14a.

Although the spring 18 urges the punch 14 in such a direction that the punch 14 comes into contact with the side edge of the lead frame 20, since the urging force of the spring 18 is set to be weak, the side burr is surely prevented from damaging the lead frame 20. Only 22 can be removed. The contact portion 14a of the punch 14 may have a width corresponding to the attachment length of the side burr 22 attached to the side edge of the lead frame 20. FIG. 5 shows the punch 14 viewed from the front. As shown in the figure, the side burr 22 adheres and remains within a certain width on both sides of the runner path, so that the abutting portion 14a of the punch 14 is attached to the side burr 2.
Set the adhesion range of 2 to the width to scrape off.

When the abutting portion 14a of the punch 14 is provided, the entire abutting portion 14a is temporarily provided with the side burr 22.
It may be provided so as to be slightly inclined when viewed from the front so that it does not come into contact with the entire surface, or may be formed as a single plate instead of being formed in a U shape as shown in FIG. Further, in order to make it easier to scrape off the side burr 22 by the contact portion 14a, unevenness may be provided on the surface of the contact portion 14.

As described above, the side burr removing mechanism of the present embodiment is adapted to the transfer timing of the lead frame 20,
The side burr 22 is removed along with the processing operation of the processing die, and the side burr 22 is partially removed only and the conventional lead frame 20 is pressed against one side to remove the side burr. The side burr can be removed without damaging the lead frame, and the side burr can be removed without deforming the guide hole by performing the removal operation with the feed pin inserted in the guide hole. become.

Since the lead frame 20 is removed while the feed pin is inserted into the guide hole, the side burr can be surely removed by operating the punch 14 at the position where the side burr is attached. The side burr removal mechanism is arranged at a stage before proceeding to the processing stage of the machining die 10, and by removing the side burr, it is advanced to the processing stage to prevent the die from being damaged. can do.

In the side burr removing mechanism of this embodiment, the size and arrangement position of the punch 14 may be appropriately set according to the lead frame product, but the side burr removing method described above can be commonly applied to different products. Even in the case of a processing apparatus for processing different kinds of products, there is an advantage that parts and the like can be used universally and that the removal mechanism is a unit so that the removal mechanism can be easily set in the processing apparatus.

[0021]

As described above, according to the side burr removing mechanism of the present invention, the side burr can be easily and surely removed without damaging the lead frame, and a good product can be surely manufactured. It will be possible. Further, the removing mechanism according to the present invention can be applied to a variety of products in a general-purpose manner, and has a remarkable effect that it can be easily attached to a processing device.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a processing apparatus equipped with a side burr removal mechanism.

FIG. 2 is an explanatory view showing an enlarged side burr removal mechanism portion.

FIG. 3 is an explanatory diagram showing how side burrs are removed by punching.

FIG. 4 is an explanatory diagram showing how side burrs are removed by punching.

FIG. 5 is an explanatory diagram showing a state in which the punch is viewed from the front direction.

FIG. 6 is an explanatory diagram showing a conventional example of a side burr removing mechanism.

[Explanation of symbols]

 7 Cylinder 8 Cutter 10 Machining Die 12 Punch Plate 14 Punch 14a Abutment 16 Support Point Pin 18 Spring 20 Lead Frame 22 Side Burr

Claims (2)

[Claims] 1. A side-burr removing mechanism for a lead frame, which is for removing side burrs partially adhered and remaining at a predetermined portion where a runner path has passed on a side edge of a lead frame after resin molding, wherein the resin mold It is located above the side burr at the lead frame feed position on the upper die of the processing device that performs the required processing such as bending of the lead while sequentially feeding the lead frame to the subsequent lead frame. A side-burr removing mechanism for a lead frame, wherein a punch for removing the side burr of the lead frame is provided. 2. An abutting portion of a punch which is abutted against a side burr and is removed so as to push down the side burr is formed in a tapered surface so that the abutting part is positioned above the side burr attachment position before the side burr is pushed down. The side burr removing mechanism for a lead frame according to claim 1, wherein a punch position is set.