JPH03264140A - Method for cutting lead of semiconductor device - Google Patents

Abstract

PURPOSE:To improve the reliability in quality by imparting such a plastic deforming force that the cut face of a lead subjected to an external plating treatment has a slope having a grade descending toward the front end part of the lead to the lead at the time of cutting the above-mentioned lead by means of a cutting die. CONSTITUTION:The semiconductor device having the lead 11 for external connection which is previously subjected to the external plating treatment is mounted on a receiving die 4. This lead 11 is then cut by the cutting die 12. Such plastic deforming force which the cut surface 11a of the lead has the slope having the grade descending toward the front end of the lead is imparted to the lead 11, by which the lead is cut. Since plating 1 can be stuck to the cut surface 11a of the lead 11 at the time of cutting of the lead, the cut surface 11a of the lead 11 can be coated with the plating 1 and the solder adhesiveness of the ensuring stage is assured. An increase in electric resistance, a decrease in joining strength, corrosion of the cut surface or the generation of a appearance defect is prevented in this way and the reliability in quality is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for cutting part of semiconductor device glue used to cut leads.

[Conventional technology]

Conventionally, a lead cutting method for this type of semiconductor device is performed through the following steps. That is, as shown in FIG. 2, a semiconductor device (not shown) having an external connection glue 2 which has been subjected to an exterior treatment with plating is placed on a receiving die 4, and then this semiconductor device ( (not shown) Glue part 2
The cutting die 5 moves up and down in the vertical direction.

In this case, during cutting, the cutting die 5 is vertically lowered from above to below. Note that the cut surface 2a of the lead 2
Plating 1 adheres to the surface due to dripping during cutting.

After this, solder for board mounting is attached to the leads 2.

[Problem to be solved by the invention]

By the way, in the conventional lead cutting method for semiconductor devices, the cut surface 2a of the lead 2 is a cut surface perpendicular to the lead protrusion direction, so the plating 1 does not adhere sufficiently to the cut surface 2a. , a part of the lead cut surface was exposed to the outside. As a result, in the next process, lead 2
The solder may not adhere to some parts of the board, and the electrical resistance may increase.
There have been problems in that the bonding strength is reduced, the lead cut surface is corroded, or the appearance is defective, resulting in a reduction in quality reliability.

The present invention was developed in view of the above circumstances, and can prevent increases in electrical resistance in leads, decreases in bonding strength, corrosion of cut surfaces, and appearance defects, thereby improving quality reliability. The present invention provides a lead cutting method for a semiconductor device that can be improved.

[Means to solve the problem]

A semiconductor device lead cuff method according to the present invention includes placing a semiconductor device having external connection leads that have been subjected to an exterior plating process on a receiving die, and then cutting the leads of this semiconductor device with a canting die. In this method, a plastic deformation force is applied to the lead during cutting so that the lead cutting surface becomes an inclined surface having a slope downward toward the lead tip.

[For production]

In the present invention, plating for exterior treatment can be attached to the cut surface of the lead when cutting the lead.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, the tank bottom etc. of this invention will be explained in detail by the Example shown in the figure.

FIG. 1 is a cross-sectional view for explaining a lead cutting method for a semiconductor device according to the present invention. In the same figure, the same members as in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the figure, a cut surface 11a of an external connection lead indicated by reference numeral 11 is formed by an inclined surface such that the lead thickness decreases from the side of the sealing resin (not shown) toward the tip. That is, the inclined surface of this lead 11 has a slope that descends toward the tip of the lead.

12 is a cutting die for cutting the lead 11, and is provided above the receiving die 4 so as to be movable up and down. The tip of this cut die 12 is connected to the cut surface 11a of the lead 11.
It is formed in a shape that fits.

Next, a lead cutting method for a semiconductor device, which is an embodiment of the present invention, will be described.

That is, lead cutting is performed by placing a semiconductor device (not shown) on a receiving die 4 having external connection leads 11 that have been previously subjected to exterior plating treatment, and then placing the semiconductor device (
This is a method of cutting a lead 11 (not shown) using a cut die 12, by applying a plastic deformation force to the lead 11 so that the lead cutting surface 11a becomes an inclined surface with a slope downward toward the lead tip. It will be done. In this case, when cutting the lead, the cutting die 12 is vertically lowered from above to below.

Thereafter, solder for board connection is attached to the leads 11.

Therefore, in this embodiment, since the plating 1 can be attached to the cut surface 11a of the lead 11 when cutting the lead, the plating 1 can be applied to the cut surface 11a of the part 11.
This can fully ensure solder adhesion to the leads 11 in the next step.

Although this embodiment shows an example in which the lead cutting surface 11a is inclined by lowering the cut die 5 vertically, the present invention is not limited to this, and for example, the lowering direction of the cut die 12 may be changed. However, the same cut surface 11a as in the embodiment can be obtained. In other words, in the present invention, it is sufficient that the plating 1 can be attached to the lead cut surface 11a by forming the lead cut surface 11a into an inclined surface that slopes downward toward the lead tip.

〔Effect of the invention〕

As explained above, according to the present invention, a semiconductor device having external connection leads that have been subjected to exterior plating treatment in advance is placed on a receiving die, and then the leads of this semiconductor device are cut by a cutting die. Since a plastic deformation force is applied to the lead during cutting so that the lead cut surface slopes downward toward the lead tip, plating for exterior treatment is applied to the cut surface of the lead when cutting the lead. This plating can cover the cut surface of the lead. Therefore, it is possible to sufficiently guarantee solder adhesion to the leads in the next process, and it is possible to prevent an increase in electrical resistance in the leads, a decrease in bonding strength, corrosion of the cut surface, or occurrence of poor appearance. Reliability can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view for explaining a lead cutting method for a semiconductor device according to the present invention, and FIG. 2 is a sectional view for explaining a conventional lead cutting method for a semiconductor device. 1...Plating, 4...Receiving die, 11...
Lead, lla...cutting surface, 12...cutting die. Deputy Masuo Oiwa 12: Kazutota〆

Claims (1)

[Claims] A method in which a semiconductor device having leads for external connection that have been previously subjected to exterior plating treatment is placed on a receiving die, and then the leads of this semiconductor device are cut with a cut die, and the leads are cut with respect to the leads. A method for cutting leads for a semiconductor device, characterized in that a plastic deformation force is applied during cutting so that the surface forms an inclined surface with a slope descending toward the tip of the lead.