JPH04299540A - Lead frame feeding device - Google Patents

Abstract

PURPOSE:To accurately feed a lead frame at the time of feeding the lead frame and to work a pilot hole without burrs, etc. CONSTITUTION:For this lead frame feeding device which carries a lead frame by positioning the frame 12 at a prescribed pitch by inserting a feed pin 10 into a pilot hole 14 provided through the frame 12, the outside diameter of the pin 10 is made larger than the dimension of the hole 14 and, at the same time, a pointed tapered section which can gets into the hole 14 is formed at the front end of the pin 10. In addition, the pin 10 is supported in such a way that the pin 10 is forced in the direction in which the pin 10 is inserted into the hole 14.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame feeding device.

0002

2. Description of the Related Art In the manufacturing process of lead frame products, processes such as punching the lead frame and bending the leads are performed after resin molding. When punching a lead frame, the punching process is performed multiple times while feeding the lead frame at a predetermined pitch. An extremely fine lead pattern is formed on the lead frame, and therefore, the lead frame must be fed with high precision in order to perform accurate processing. When processing a lead frame using a processing die, conventionally a pilot pin was provided on the die, and during processing, the pilot pin was inserted into a pilot hole provided in the lead frame to position the lead frame relative to the die. Process it. In addition, when feeding the lead frame, it is possible to feed the lead frame accurately at a predetermined pitch by installing a feed pin on the feed bar provided for feeding the lead frame, and inserting this feed pin into the pilot hole of the lead frame. I have to.

As mentioned above, the pilot hole of the lead frame plays an important role in positioning the lead frame, but the sealing resin may shrink after resin molding.
Since the lead frame is bent or deformed due to various causes such as the heat treatment history of the base material, a problem arises in that the pilot hole position, which has been accurately set in advance, deviates from the normal position. There are various causes for lead frame deformation, but if the lead frame is deformed and the pilot hole position shifts, the feed pin may pry the inner edge of the pilot hole when feeding the lead frame. Therefore, conventional methods have been adopted in which the diameter of the pilot hole is set slightly larger than the outer diameter of the feed pin to prevent the feed pin from damaging the pilot hole during feeding.

FIG. 6 shows a state in which a lead frame is fed by a feed pin. The figure on the right shows a state in which the feed pin 10 is inserted into the pilot hole 14 of the lead frame 12, and the figure on the left shows a state in which the lead frame 12 is fed. The positional relationship between the feed pin 10 and the pilot hole 14 is shown below. As shown, feed pin 10
is inserted into the center of the pilot hole 14, and when feeding the lead frame 12, it is fed while coming into contact with the front edge of the pilot hole 14. Since there is some play between the pilot hole 14 and the feed pin 10, there is a difference between the pitch A of the pilot hole 14 and the feed pitch B of the feed pin 10 due to this play.

[0005]

[Problems to be Solved by the Invention] As mentioned above, conventionally the lead frame is fed with a play between the feed pin and the pilot hole, but it is difficult to smoothly insert the feed pin into the pilot hole. .2mm ~
A play of 0.4 mm is required. Therefore, when the lead frame is fed by the feed pin, the lead frame shifts back and forth due to the play between the pilot hole 14 and the feed pin 10, as shown in FIG. In the figure, C is the amount of deviation of the lead frame. FIG. 8 shows a state in which a pilot pin 16 is inserted into a pilot hole 14 in order to position a lead frame 12 in a mold for processing. The inner edge is pried to create a burring 18. This burring occurs both when the pilot pin enters the pilot hole and when it exits from the pilot hole; when the pilot pin enters, burring occurs downward, and when the pilot pin exits, burring occurs upward.

[0006] Recent lead frames tend to have more pins, and as a result, extremely thin lead frame materials are being used. For this reason, even when the pin position of the pilot pin and the pilot hole are slightly misaligned, the above-mentioned burring is likely to occur. For products with conventional lead frames whose material thickness exceeds a certain level, even if the pilot hole position is slightly off, it is possible to correct the position and process it. The amount of correction is 0 for the lead frame product used.
．． The maximum limit is about 1 mm. If burring occurs during machining, the accuracy of the feed will decrease, and proper machining will not be performed in the next process, resulting in defective products. The present invention has been made to solve the above problems, and its purpose is to accurately feed products without causing problems such as burring even when processing lead frames using thin materials. The purpose of the present invention is to provide a lead frame feeding device that can perform processing with high precision.

[0007]

Means for Solving the Problems The present invention has the following configuration to achieve the above object. That is, in a lead frame feeding device that inserts a feed pin into a pilot hole provided in a lead frame, positions the lead frame at a predetermined pitch, and transfers the lead frame, the outer diameter of the feed pin is larger than the hole size of the pilot hole. The present invention is characterized in that a tapered portion is formed at the tip of the feed pin to enter the pilot hole, and the feed pin is biased and supported in the insertion direction of the pilot hole.

[0008]

[Operation] When inserting the feed pin into the pilot hole of the lead frame and feeding the lead frame at a predetermined pitch, the tapered part at the tip of the feed pin enters the pilot hole and contacts the inner circumference of the pilot hole at an appropriate position to lead the lead frame. Frames can be positioned and sent.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is an explanatory diagram showing the main parts of an embodiment of a lead frame feeding device according to the present invention. The lead frame feeding device of this embodiment is capable of feeding the lead frame with high precision by making the feed pin 10 inserted into the pilot hole 14 into a float structure when feeding the lead frame 10 at a predetermined pitch. . The float structure of the feed pin 10 is such that the feed pin 10 is biased in a direction to press the lead frame 10, and the lead frame 12 is positioned by the biasing force. In the case of this embodiment, the feed pin 10 is not inserted into the pilot hole 14, and in order to hold down the lead frame 12 with the feed pin 10, the outer diameter of the feed pin 10 is set larger than the hole diameter of the pilot hole 14, and the feed pin 10 is not inserted into the pilot hole 14. 10 is formed into a tapered shape.

In FIG. 1, 20 is a lead frame feed arm, and the feed pin 10 is attached to an L-shaped support block 22 fixed to the feed arm 20 via a spring 24. The spring 24 is resiliently attached between the flange 10a provided on the rear side of the feed pin 10 and the support block 22, and is floatable so that the feed pin 10 is held down by a constant biasing force when holding down the lead frame 12. It is set up.

FIG. 2 shows an enlarged view of the lead frame 12 held down by the feed pin 10. feed pin 10
As described above, the tapered portion 10b is formed at the tip of the lead frame 12, so that when feeding the lead frame 12, the tip of the tapered portion 10a partially enters into the pilot hole 14 and can be held down. In this way, by providing the tip of the feed pin 10 in a tapered shape and supporting it so that it can float, there is no need to set the hole diameter of the pilot hole 14 large to provide play, and the position of the pilot hole 14 can be set with high precision. Even if the lead frame 12 is placed in the feed pin 10, the inner circumferential edge of the pilot hole 14 comes into contact with the tapered portion of the feed pin 10 at an appropriate position, so that the lead frame 12 can be accurately positioned and fed. As a result, the deviation of the pilot hole 14 is reduced, and even when positioning the pilot pin by inserting it into the pilot hole in the mold, burring can be effectively prevented and highly accurate machining can be performed. be able to. Note that the method of floating and supporting the feed pin 10 is not limited to the above embodiment. In the above embodiment, the support block 22 is fixed and the feed pin 1 is
0 is floated relative to the support block 22,
A method is also possible in which the support block 22 is floated relative to the feed arm 20 and the feed pin 10 is fixedly supported by the support block 22.

FIGS. 3, 4 and 5 show an example of an actual feeding device using the feed pin 10 having the above-mentioned float function. FIG. 3 is a plan view of the feeding device, and FIG. 4 is a front view. The lead frame is fed from right to left in the diagram. In the figure, 20a and 20b are feed arms to which feed pins 10 are attached downward, and are provided at a predetermined interval in order to take up a space for placing a mold in the middle. The structure for floating the feed pin 10 and attaching it to the feed arms 20a, 20b is the same as in the above embodiment. The feed arms 20a, 20b are ball bush shafts 3 that are moved back and forth by a cylinder 30.
2, and the ball bush shaft 32 is slidably supported by LM bearings 34, 34. A stopper 36 is provided at a position a certain distance from the tip of the ball bushing shaft 32 to define the forward movement position of the ball bushing shaft 32. The feed arms 20a and 20b move back and forth as the ball bushing shaft 32 moves back and forth, but the feed arm 20a moves back and forth by sliding a cam follower 38 extending to the side of the ball bushing shaft 32 on the lower surface of the guide 40. do. The ball bushing shaft 32 is rotatable around its axis, and the cam follower 38 is rotated around the guide 40.
By making contact with the feed arms 20a and 20b, the tips of the feed arms 20a and 20b are prevented from descending below a certain height.

[0013] The above-mentioned feeding device is provided with a mechanism for detecting a feeding error when the feed pin 10 does not enter the pilot hole of the lead frame when feeding the lead frame. FIG. 5 is a side view of this detection mechanism. In the figure, 32 is a ball bushing shaft supported by an LM bearing 34, a detection arm 42 is extended from the side surface of the ball bushing shaft 32, and one end side of a rotating plate 44 is attached to the lower surface of the tip of the detection arm 42. come into contact with Rotating plate 44
is rotatably supported by a shaft 46 attached to the body, and a contact pin 48 is erected at the other end of the rotary plate 44. The contact pin 48 contacts a contact portion of the limit switch 50. Reference numeral 52 denotes a spring that constantly biases one end of the rotating plate 44 to lift it upward. spring 52
By lifting the tip side of the detection arm 42, the feed arms 20a and 20b are moved through the ball bushing shaft 32.
It acts to lower the tip side of the

When feeding the lead frame, the feed pin 10 enters the pilot hole of the lead frame and transfers the lead frame. Therefore, when normal feeding is performed, the tips of the feeding arms 20a, 20b descend to predetermined positions. The above-mentioned detection mechanism checks for a feeding error by detecting that the feed arms 20a, 20b are in a floating state without entering the pilot hole accurately when feeding with the feed pin 10. That is, when the feed pin 10 presses the part other than the pilot hole position and the tip side of the feed arms 20a, 20b is raised, the tip side of the detection arm 42 is biased by the biasing force of the spring 52 as shown by the arrow in FIG. The rotating plate 44 acts as a lever to push the contact pin 48 down.
The feed error can be detected by turning the limit switch 50 ON and OFF. Although the preferred embodiments as a lead frame feeding device have been described above, the present invention is not limited to the above embodiments, and can be suitably used when processing a lead frame while feeding it at a predetermined pitch. Can be done.

[0015]

According to the lead frame feeding device of the present invention, it is possible to feed the lead frame by positioning it with the feed pin without providing any extra play in the pilot hole provided in the lead frame, and to feed the lead frame with high precision. You can perform frame forwarding operations. In addition, since the installation accuracy of the pilot hole can be improved, even when processing products using thin lead frame materials with a mold, the pilot hole can be processed without burring, ensuring reliable processing. It has great effects, such as being able to perform

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a configuration for supporting a feed pin.

FIG. 2 is an explanatory diagram showing an enlarged tip of a feed pin.

FIG. 3 is a plan view of an embodiment of a lead frame feeding device.

FIG. 4 is a front view of an embodiment of a lead frame feeding device.

FIG. 5 is an explanatory diagram showing a feeding error detection mechanism in a lead frame feeding device.

FIG. 6 is an explanatory diagram showing a method of feeding a lead frame using a feed pin.

FIG. 7 is an explanatory diagram showing the positional deviation of the pilot hole during feeding by the feed pin.

FIG. 8 is an explanatory diagram showing how burring is performed by a pilot pin.

[Explanation of symbols]

10 Feed pin 10b Taper part 12 Lead frame 14 Pilot hole 16 Pilot pin 18 Burring 20 Feeding arm 22 Support block

Claims (1)

[Claims] 1. In a lead frame feeding device that inserts a feed pin into a pilot hole provided in a lead frame, positions the lead frame at a predetermined pitch, and transfers the lead frame, the outer diameter of the feed pin is set to be smaller than the hole dimension of the pilot hole. The lead frame is also formed to have a large diameter, and a tapered part that enters the pilot hole is formed at the tip of the feed pin, and the feed pin is biased and supported in the insertion direction of the pilot hole. Feeding device.