JPS634944B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a cutting and shaping machine, and more particularly to an improvement in the cutting section of an automatic integrated circuit cutting and shaping machine.

(2) Background of the technology In the production of plastic integrated circuits (ICs) with molded packages, an automatic cutting and shaping machine is used to move the process of separating the molded packages from the lead frame. This part, called the cutout part, is shown in the plan view of FIG. 1 is moved in the direction of the arrow by a pusher 4 that moves in the direction of the arrow. The pusher 4 is an elongated rod-shaped body that is configured to be able to reciprocate like a piston in the direction of the arrow by a mechanism not shown.

As shown in FIG. 2, the lead frames 1 are stacked in a magazine 5, and are moved one by one from the bottom of the magazine 5 in the direction of the arrow by a pusher 4. In FIG. 2, 6 indicates the bottom of the magazine, 7 indicates the outlet of the lead frame 1, and 8 indicates the insertion opening of the pusher 4.
1 is shown when the lead frame in FIG. 1 is viewed from the side, and in the following figures, the same parts as those already illustrated are designated by the same reference numerals. In the cut-out section shown in the figure, a weight is placed on the top of the stack of lead frames in order to forcibly correct any bends or curls in the frame and to ensure stable operation of lead frame cut-out. Therefore, the load of the other lead frames and the weight will be applied to the lowest lead frame. Molded package cages are stamped with characters for purposes such as product recognition, and molded package cages that have become products must have characters stamped on them, so the lead frame comes to the cutout part. If no characters or the like have been stamped before, the stamp will be done in a later step.

(3) Prior art and problems When cutting out the lead frame described above, the load mentioned above is applied to the lowest lead frame that is pulled out, so the friction on the surface of the mold package is large, and the upper and lower mold package Scratches may occur due to rubbing between surfaces, or stamped characters may fade or disappear. Even if the seal has not yet been stamped, if the surface of the mold package is scratched, subsequent stamping may not be done clearly.

(4) Purpose of the Invention In view of the above-mentioned conventional problems, an object of the present invention is to provide a cutting section that reduces friction on the surface of a mold package when cutting out a lead frame in an IC automatic cutting and shaping machine. do.

(5) Structure of the Invention According to the present invention, the cutting and shaping machine is equipped with a pusher that sequentially pushes out the lead frames from below from the bottom of a magazine in which lead frames equipped with mold package cages are stacked and stored. The bottom of the magazine is formed low with a step from the middle in the feed direction of the lead frame, and the pusher for pushing out the lead frame has a contact protrusion at its tip that is thinner than other parts when pushing out the lead frame. A cutting and shaping machine characterized in that a tapered part is formed on the upper surface of the lead frame and is inclined upward from the tip, and a part that becomes thicker than the lead frame from the middle of the tapered part to the rear is formed. This is achieved by providing

(6) Examples of the invention Examples of the invention will be described in detail below with reference to the drawings.

FIG. 4 shows a cutout portion of the automatic IC cutting and shaping machine according to the present invention in cross section, and in the illustrated embodiment, the bottom 16 has a step formed halfway in the feed direction of the lead frame. That is, a portion 16a of the bottom 16 is formed low with a step of Δl. This lowered portion 16a is the lead frame 1
It is provided on the side of the outlet 17 of the
The remaining portion 16b excluding 6a is lead frame 1.
Set it so that it is wide enough to receive a stack of items without tipping over. Magazine 15
The lead frame outlet 17 and pusher insertion port 18 are provided in the same way as in the conventional example, and the shape thereof is as understood from FIGS. 4 and 1.
The lead frames are stacked in a recessed part of the elongated tank, and a weight (not shown) is conventionally placed on top of the stack or lead frames.

On the other hand, the pusher 14 has the same structure and movement mechanism as the conventional pusher 4, but
Add the following improvements. That is, the diameter of the pusher is formed to be larger than the thickness of the mold package by Δd so that its height (or diameter) is larger than the thickness of the mold package 2 of the lead frame.

Thus, lead frame 1 and pusher 14
and are lined up on the bottom portion 16b of the magazine 15, the upper surface of the pusher 14 is higher than the upper surface of the mold package 2. In addition, Pushya 1
The leading end portion of No. 4 is tapered.

When the pusher 14 is further inserted into the magazine 5 from the state shown in FIG. 3, the leading end portion of the pusher 14 comes into contact with the right end portion of the molded package 2 as viewed in the figure. As the pusher 14 is advanced further to the left, the lead frame 1 is pushed to the left, with the tapered leading end portion of the pusher 14 contacting the lower portion of the molded package of the second lead frame from the bottom. When the pusher 14 is further advanced to the left, the lead frame 1 that has been pushed is located on the lower bottom portion 16a, and at this time, the upper surface portion S of the maximum diameter portion of the pusher 14 is in contact with the mold package of the next lead frame. fully contacts and supports the lower surface,
Since the lowest lead frame and the next lead frame are completely separated, there is no possibility of scratches or friction caused by the rubbing of the mold package cage of the lowest lead frame and the mold package cage of the next lead frame while the lowest lead frame is moving. is completely prevented.

FIG. 4 shows the situation when the mold package 2 has completely moved onto the lower bottom part 16a. In order to prevent the pusher 14 from damaging the lower surface of the mold package during the transition to the state shown in the figure, the connecting portion from the tapered tip portion of the pusher 14 to the maximum diameter portion is rounded and formed smoothly. The tip of the pusher 14 is shaped so that it can come into direct contact with the mold package.

On the other hand, at the bottom 16 of the magazine 15, when the molded package of the lead frame transitions from the portion 16b to the lower portion 16a, a connecting portion between the portions 16b and 16a is provided so that the stepped portion of the bottom 16 does not damage the molded package. Also round it and form it smoothly.

The cutout portions formed as described above are arranged in the same manner as in the conventional example shown in FIG. The number of pushers to be placed at each lead frame position is determined by calculating the dimensions of the lead frame, the number of mold packages, the weight, etc.

(7) Effects of the invention As explained in detail above, according to the present invention, when cutting out stacked lead frames,
This is highly effective in improving the production yield of plastic ICs because damage and wear caused by rubbing of the molded packages against each other is prevented.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of a cutting section of a plastic IC automatic cutting and shaping machine, FIG. 2 is a schematic sectional view of a conventional cutting section, and FIGS. 3 and 4 are cross sections of a cutting section according to the present invention. It is a diagram. 1... Lead frame, 2... Mold package, 3... Lead, 4, 14... Pusher, 5, 1
5... Magazine, 6, 16... Bottom of magazine, 16a
...lower part of bottom 16, 16b...portion other than bottom 16a, 7, 17...lead frame outlet, 8, 18
...Pushyah insertion port.

Claims (1)

[Scope of Claims] 1. A cutting and shaping machine equipped with a pusher that sequentially pushes out the lead frames from below from the bottom of a magazine in which lead frames equipped with mold package cages are stacked and housed, wherein The pusher for pushing out the lead frame has a contact protrusion at its tip that is thinner than other parts when pushing out the lead frame, and the upper surface of the pusher has a contact protrusion for pushing out the lead frame. A cutting and shaping machine, characterized in that a tapered part is formed that slopes further upward, and a part that becomes thicker than the lead frame from the middle of the tapered part to the rear is formed.