JPH0472653A - Lead shaping apparatus - Google Patents

Abstract

PURPOSE:To prevent a plated part on the surface of a lead from being stripped by providing the following: a metal mold in which a recessed part matched to a shaping form has been formed; and a sheetlike elastic body which can freely by moved by following the movement of the lead which is bent along the surface of the recessed part. CONSTITUTION:When a semiconductor device 19 is pressed by using an upper metal mold 21, a lead 20 is bent along the face of a recessed part 18, and a lead tip part 20a is arranged at the lower part of the device 19. At this time, the coefficient of friction between the lead 20 and a sheetlike elastic body 15 is extremely larger than the coefficient of friction between a second block 12 and the elastic body 15. As a result, the elastic body 15 is bent along the face of the recessed part 18 by following the lead 20. That is to say, since no friction with other members is caused on the surface of the lead 20, the surface of the lead 20 is not damaged. After the shaping operation of the lead 20 of a prescribed amount has been completed, the upper metal mold 21 is moved upward. Thereby, the elastic body 15 is restored to an initial state by a spring material 16.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a technology for manufacturing semiconductor devices, and particularly to a technology that is effective when applied to lead forming technology.

[Conventional technology]

FIGS. 8 and 9 are schematic cross-sectional views of a conventional lead forming apparatus. 1 is a lower mold, on the surface of which is a semiconductor device 2.
The tip 3 of the lead 3 protruding from the side of the pan cage.
A recess 4 is formed in the direction in which the leads are arranged to form a so-called J-bend shape in which the semiconductor device 2 is bent to the inside of the back surface of the semiconductor device 2. Reference numeral 5 denotes an upper mold for pressing the semiconductor device whose leads are bent downward at 90 degrees from the top of the pan cage and bending the leads 3 along the recess 4 while squeezing them.

[Problems to be Solved by the Invention] The inventors of the present invention have found that the following problems occur when using the lead forming apparatus as described above.

(1) When plating is formed on the surface of the lead 3 by the ironing operation, there is a problem that the plating rubs against the recess 4 of the lower mold 1 and peels off.

(2) Peeled plating chips accumulate in the recess 4, and the plating chips adhere to the leads of the semiconductor device to be bent next, resulting in a short-circuit between the leads.

(3) As the plating on the surface of lead 3 peels off,
There is always a risk that the lead will corrode.

(4) As the plating on the surface of the lead 3 peels off,
The wettability of the solder deteriorates, resulting in defects in mounting the semiconductor device on the mounting board.

An object of the present invention is to provide a lead forming technique that can solve the above problems.

Another object of the present invention is to provide a technique that can improve the reliability of a semiconductor device in which the leads are plated before being molded.

The above and other objects and novel features of the present invention include:
It will become clear from the description of this specification and the accompanying drawings.

[Means to solve the problem]

A brief overview of typical inventions disclosed in this application is as follows.

In other words, it bends to follow the bending of the lead while protecting the surface of the lead, and prevents the lead from coming into direct contact with the lead bending member.

[Effect]

According to the above means, since the leads do not come into direct contact with the lead bending member, it is possible to prevent the plating on the lead surface from peeling off, and to improve the quality of the semiconductor device.

〔Example〕

FIG. 1 is a schematic diagram of a lead forming apparatus according to an embodiment of the present invention, and FIGS. 2 to 7 are explanatory diagrams of the operation of the embodiment of FIG. 1. A detailed explanation will be given below according to the drawings. The lower mold of the lead forming apparatus 9 of this embodiment is divided into three blocks. Reference numeral 11 denotes a first block that serves as a base for fixing the second and third blocks, and is shaped like a square with a groove 11a provided therein.
A recess 11b is formed into which the bottom 12a of the recess 11b fits.

Both surface edges 11c of the first block 11.

11d is a third block 13a having a substantially key-shaped cross section.

13b are attached respectively. The inner surface 14 formed by the first block 11 and the second block 12 has a substantially arcuate cross section, and a plate-shaped elastic body 15 is provided along the inner surface 14 in the initial state. . Reference numeral 16 denotes a spring member that urges the plate-shaped elastic body 15 in the direction of the inner surface 14, and one end of the spring member is clamped and fixed between the first block 11 and the second block 12 similarly to the plate-shaped elastic body 15 described above. There is. The other end of the plate-like elastic body 15 protrudes into a recess 18 formed by the surface 12b of the second block 12 and the side surface 17 of the third block 13, and the side surface of the third block 13 which has a curved surface. It comes into contact with the tip 20a of the lead 20 that has moved along the section 17. The curved shape of the recess 18 is set to match the bent shape of the beam 20. Note that 21 is an upper mold for applying lead bending load.

Next, the operation of this embodiment will be explained. As shown in FIG. 2, the molded semiconductor device 19 is first molded by bending its tip 20a into an arched shape using a bending means such as an a-chie 22, and then the semiconductor device 19 is molded as shown in FIG. Then, the sheet is bent by approximately 90'' using a roller 23 or the like to perform a second forming.

Next, as shown in FIG. 4, the semiconductor device 19 is transported to the lead forming apparatus 9 by a transporting means (not shown), and the recess 18 of the lead forming apparatus 9 is bent by 90'' and formed corresponding to the arrangement direction of the leads 20. The lead 20 is set inside.At this time, the tip end 20a of the lead is not placed directly on the surface of the second block 12, but on the plate-shaped elastic body 15 as shown in FIG. Note that the side surface 17 of the third block 13 is formed of a curved surface, and the tip end 20 of the lead
Since the lead a is bent along the above-mentioned curved surface, there is no possibility that the lead tip 20a will be bent outward. Next, as shown in FIG. 6, by pressing the semiconductor device 19 with the upper mold 21, the leads 20 are bent along the surface of the recess 18, and the lead tips 20a are attached to the bottom of the semiconductor device 19. It will be placed. At this time, the coefficient of friction between the lead 20 and the elastic plate 15 is much larger than the coefficient of friction between the second block 12 and the elastic plate 15, so as shown in FIG. 15 follows the lead 20 and bends along the surface of the recess 18. That is, since the surface of the lead 20 (the lead tip 20a) does not cause friction with other members, the surface of the lead 20 is not damaged.

After the molding of a predetermined amount of glue 20 is completed, the upper mold 21
When the plate-shaped elastic body 15 is moved upward, the elastic plate 15 is restored to its initial state by the spring material 16.

Next, the effects of this embodiment will be explained.

(+) By providing a protective member between the lead and the lower mold that bends as the lead bends, it is possible to prevent the lead from coming into direct contact with the surface of the lower mold and causing friction. , it is possible to avoid the problem of damaging the plating formed on the surface of the lead.

(2) As a result of the above, peeling of the plating does not occur, so there is no problem of failure in attachment to the mounting board due to soldering or the like.

A plate-shaped elastic body is provided that can freely slide along the concave surface of the lower mold formed to bend the lead, and pressure is applied from above to cause the plate-shaped elastic body to move along the concave surface when the lead is bent. By sliding and bending the lead while keeping it stationary against the apparently plate-like elastic body, the lead surface comes into contact with the lower mold and the plating formed on the lead surface is peeled off. It is something that can solve problems.

(3) According to (1) and (2), it is possible to prevent the problem of defective mounting when attaching a semiconductor device to a mounting board.

(4) (1) and (2) provide the effect of preventing the problem of lead corrosion.

(5) Since no plating debris is generated as in the conventional method, it is possible to eliminate the periodic polishing process of the lower mold, and the operating rate of the lead forming apparatus can be dramatically improved.

(6) As described above, since defects occurring during lead molding are reduced, appearance inspection can be simplified.

The invention made by the present inventor has been specifically explained above based on Examples, but it goes without saying that the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. do not have.

For example, when the lead of a semiconductor device is lowered, the pressure causes the plate-shaped elastic body to move to follow the lead, but the plate-shaped elastic body moves by itself in conjunction with the lowering movement of the upper mold. You may also do so.

Furthermore, although the present invention has been described with reference to the case of molding J-shaped leads, it may also be used to mold gull-wing type leads.

〔Effect of the invention〕

The effects obtained by typical inventions disclosed in this application are as follows.

That is, the lead can be formed without damaging the plating on the lead surface.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of a lead forming apparatus which is an embodiment of the present invention. Figures 2 to 7 are explanatory diagrams of the lead forming process; Figure 8;
FIG. 9 is an explanatory diagram of a conventional lead forming apparatus. 10... Lead forming device, 11. First block, 11
a-groove, 11b/recess, llc, 1ld-surface, 12
...Second block, 12a...Bottom, 13a. 13b...Third block, 14.Inner surface, 15.Plate-like elastic body, 16.Spring material, 17..Side portion, 18. Recessed portion.

Claims (1)

[Claims] 1. A lead molding device for molding a lead exposed from a package of a semiconductor device into a predetermined shape, including a mold having a recess formed in accordance with the molding shape, and the mold and the lead. A lead forming device characterized by having a plate-like elastic body inserted between the recess and the recess, and movable to follow the movement of the lead bent along the surface of the recess. 2. The lead forming device according to claim 1, wherein the plate-like elastic body is movable by action from the lead. 3. The lead forming device according to claim 1 or 2, wherein the plate-like elastic body is biased by a spring member for restoring the lead to its initial state when it is separated. . 4. In a lead forming device that forms the third portion exposed from the package of a semiconductor device into a predetermined shape, there is a bending member that bends the lead, and a lead surface portion to which the bending member acts. A lead forming device characterized in that a movable body that moves together with the lead according to the bending member is located between the bending member and the lead.