JP2625867B2 - IC lead forming equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for forming leads of an IC, and more particularly to an apparatus for forming leads of a flat package in four directions or two directions.

[Conventional technology]

Generally, QFP (Quad Flat Package) and SOP (Small Out Package)
In the case of ICs that are called “Lne Package” and project Gull Wing leads in four directions or two directions from the package body (hereinafter collectively referred to as ICs), the molding of the leads is made of resin. This is performed after sequentially passing through the steps of punching the dam portion, cutting the tie bar, and cutting the lead.

As a conventional lead forming apparatus of this type, the one shown in FIG. 3 has been proposed. That is, as shown in FIG.
An ejector pin 22 that receives the IC package 1 and can move up and down via a spring 21 and a molding die 23 that receives the lead 2 projecting in four or two directions from the IC package are disposed below. Lead 2 through 24
A pad 25 which presses the root of the ejector pin 22 from above with respect to the ejector pin 22, and a forming punch 28 which is located on the side of the pad 25 and moves up and down independently of the pad are arranged on the upper side.

When the pad 25 first descends as shown in FIG. 3 (a), the root 2a of the lead 2 of the IC package 1 is clamped by the pad 25 and the rib 23a of the forming die 23.
After that, the forming punch 28 descends vertically while rubbing the surface of the lead 2 downward, and clamps the lead tip 2c with the forming die 23 and the forming punch 28 as shown in FIG. 3 (b). The leads are formed along the ribs 23a provided on the forming die 23.

[Problems to be solved by the invention]

In the above-described conventional lead forming apparatus, the forming punch 28 descends while rubbing the surface of the lead 2 during forming to perform lead forming. Therefore, when the solder plating applied to the lead surface comes into frictional contact with the forming punch 28, the solder plating may be peeled off, and the underlying metal portion of the lead 2 may be exposed and corrosion may progress. In addition, there is a problem that the peeled solder plating debris adheres to the surface of the die or the forming punch, which adversely affects the lead forming accuracy, or adheres between the leads during the formation of the debris to short-circuit the leads. . Therefore, there is also a problem that a large number of man-hours are required, such as visually inspecting plating peeling and frequently removing plating dust attached to a punch or a die.

Particularly, in recent years, due to the demand for high-density mounting, the inclination angle α of the inclined portion 2b of the lead 2 tends to be as small as about 0 ° to 10 ° as shown in FIG. With the conventional lead forming apparatus, the smaller the inclination angle α, the more the forming punch rubs the lead surface, which is becoming disadvantageous to the above-mentioned problem.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide an IC lead forming apparatus capable of forming without rubbing the lead surface.

[Means for solving the problem]

A lead forming apparatus according to the present invention includes a forming die that supports a root portion of a lead projecting substantially horizontally from an IC package at a lower portion and has a rib corresponding to a lead inclined portion, and a forming die having the root portion of the lead. And a pad pressed from above against the rib, and can be moved only on a straight line which is disposed opposite to the rib and has an oblique angle in the horizontal direction with respect to the lead. And a slide cam that has a cam surface that is in surface contact with the forming punch, and that operates to move the forming punch when driven when driven.

[Operation] In the configuration described above, the forming punch for forming the lead is
Since it moves from an oblique direction having a certain angle with respect to the lead and comes into contact with the lead, the amount of the forming punch rubbing the lead surface is reduced, and the plating peeling on the lead surface is suppressed.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a schematic sectional view of a first embodiment of the present invention. FIG. 1 (a) shows a state before lead molding and FIG. 1 (b) shows a state during lead molding.

As shown in these figures, the lead forming apparatus has an ejector pin 12 that can move the IC package 1 up and down via a spring 11 and a forming die 13 that receives the lead 2 on the lower side. The molding die 13 is a rib 13a for supporting the root of the lead 2 protruding from the IC package 1.
The rib 13a is formed at an angle corresponding to the inclined portion 2b of the lead 2 to be formed.

On the other hand, the lead 2 is connected to the molding die via a spring 14.
Pad 15 that is pressed from above against 13, and this pad 15
A slide guide 16 having a guide surface which is located on the side of the slide guide and is inclined at a predetermined angle with respect to the horizontal direction is disposed on the upper side. The slide guide 16 supports a slide cam 17 having a cam surface inclined at the lower end so as to be movable up and down, and has an inclined cam surface in contact with the cam surface of the slide cam 17. It has a forming punch 18 that can linearly reciprocate in an oblique direction along the guide surface of the slide guide 16 as it moves.

According to this configuration, first, as shown in FIG. 1A, when the pad 15 is lowered, the lead 2 is clamped by the pad 15 and the forming die 13 at the root 2a.

Thereafter, when the slide cam 17 is independently lowered, the cam surface of the slide cam 17 is pressed down while the cam surface of the slide cam 17 contacts the cam surface of the forming punch 18, and the forming punch 18 is inclined downward along the guide surface of the slide guide 16. Go to
Then, since the forming punch 18 comes into contact with the lead 2 and is further lowered obliquely downward, the leading end 2c of the lead is clamped by the forming die 13 and the forming punch 18 as shown in FIG. Is formed along the rib 13a of the forming die 13. In this case, the forming punch 18 makes contact with the front end portion of the lead 2 at the tip end portion 18a thereof, bends the lead 2 obliquely inward at the angle of the forming punch end portion 18a, and finally reaches a position where it abuts the rib 13a. Move to perform lead molding.

For this reason, compared with the conventional structure in which the forming punch descends vertically, the amount of rubbing of the lead surface when the forming punch tip 18a moves is reduced, and the peeling of the solder plating can be reduced. In particular, as the inclination angle α of the lead inclined portion 2b is smaller,
The amount of movement of the punch tip 18a while rubbing on the lead surface can be greatly reduced, and stable lead molding can be performed.

The angle of the guide surface of the slide guide 16 is set so as to minimize the range in which the forming punch rubs the lead surface according to the value of the inclination angle α of the inclined portion 2b of the lead 2. Is determined by

FIG. 2 is a schematic sectional view of a second embodiment of the present invention. FIG. 2 (a) shows a state before lead molding, and FIG. 2 (b) shows a state during lead molding. Also, in these figures,
The same or equivalent parts as those in FIG. 1 are denoted by the same reference numerals.

In this embodiment, the slide cam 17A for driving the forming punch 18A is configured to move in the horizontal direction, and the cam surface of the slide cam 17A and the cam surface of the forming punch 18A are moved by moving the slide cam 17A horizontally from both sides. The forming punch 18A is moved obliquely downward by contact with
The molding of the lead 2 is realized.

In this embodiment, since the drive mechanism of the slide cam 17A can be disposed around the device, this type of structure can be simplified, the implementation is easy, and the maintenance is excellent.

〔The invention's effect〕

As described above, according to the present invention, since the forming punch for forming a lead moves only on a straight line in an oblique direction having a certain angle with respect to the lead and contacts the lead, the amount of the forming punch rubbing the lead surface is reduced. It can reduce the peeling of plating on the lead surface, prevent lead corrosion, stabilize product quality, and suppress the generation of plating debris, and perform man-hours such as visual inspection of punches and removal of plating debris. Can be reduced and the effect of automating the equipment can be greatly improved.

[Brief description of the drawings]

FIGS. 1A and 1B are schematic sectional views of a first embodiment of the present invention, FIGS. 2A and 2B are schematic sectional views of a second embodiment of the present invention, and FIGS. a) and (b) are schematic sectional views of a conventional structure, and FIG. 4 is a front view of a part of an IC showing a lead molding state. 1 ... IC package, 2 ... Lead, 2a ... Root part, 2b
…… Slope, 2c …… Tip, 11,21 …… Spring, 12,
22 …… Ejector pin, 13,23 …… Forming die, 13a, 23a
…… Rib, 14,24 …… Spring, 15,25 …… Pad, 16
…… Slide guide, 17,17A …… Slide cam, 18,18
A, 28: Molding punch, 18a: Tip.

Claims (1)

(57) [Claims] 1. An IC lead forming apparatus, wherein a lead protruding substantially horizontally from an IC package has a lead inclined portion inclined at an intermediate portion in a longitudinal direction thereof with respect to a horizontal direction. A forming die that supports a root portion of a horizontally protruding lead below and has a rib corresponding to a lead inclined portion; a pad that presses the root portion of the lead against the forming die from above; A forming punch that is disposed opposite to and can move only on a straight line having an oblique angle in the horizontal direction with respect to the lead, and when moved, the tip abuts on the lead and bends the lead along the rib. A cam surface that comes into surface contact with the forming punch, and a slide cam that moves when the cam is driven to move the forming punch on the straight line. C lead molding equipment.