JPH0245966A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent a short circuit between leads by inserting a dummy semiconductor device equipped with an external lead which is plated with its plating material that is different from a facing plating material for the external lead between semiconductor devices which are being produced in large quantities during the process of molding and then, removing foreign substances which are attached to treating molds. CONSTITUTION:An external lead 6 which is treated by a plating treatment that is different from that of an external lead 4, for example, the plating treatment with Ag is inserted in a process of mass production and then, molding is performed. Solder deposit 5 on the side face of punch 1 is bonded to the lead 6 and it is removed completely. As to frequencies of mold treatment which is performed by inserting the lead 6 treated with Ag plating that is different from plating of the lead 4 into a normal mass production process, it may be as well to choose its adequate time-intervals according to treating conditions and the like. Any short circuit between the leads 4 is thus prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for molding external leads of a semiconductor device that prevents the attachment of foreign matter.

[Conventional technology]

FIG. 2 is a perspective view showing a packaged semiconductor device with external leads molded thereon. In addition, Fig. 3(a) to (f)
> is a partially enlarged view showing a process of molding an external lead into the predetermined shape shown in FIG. 2, for example, using a molding die.

In FIG. 3, 1 is a punch, 2 is a bending pin, 3 is a packaged semiconductor device, 4 is an external lead protruding from the semiconductor device 3, and 5 is the punch 1 connected to an external lead 4.
The solder plating on the surface of the external lead 4 is scraped off by contact with the punch 1, and the solder plating is fixed to the side surface of the punch 1 in the shape of a whisker.

Next, the operation will be explained.

The external lead 4 is formed into a predetermined shape using the punch 1 according to the steps shown in FIG. That is, as shown in FIG. 3(a), the external lead 4 set in the bending die 2 is clamped with the downward movement of the punch 1, and as shown in FIG.
As shown in b), the external lead 4 is bent. At this time, since the punch 1 comes into contact with the surface of the external lead 4, the solder plating on the surface is scraped off by the punch 1 as shown in FIG. 3(C). Solder beard 5 shaved off like this
is fixed to the side surface of the punch 1 in the form shown in FIG. 3(d). At the initial stage, the solder beard 5 is small, but as it is pressed many times, it grows as shown in FIG. 3(e), and when it reaches a certain size, it becomes a punch as shown in FIG. 1 and becomes stuck to the external lead 4. This situation is shown in FIG.

In order to prevent the solder whiskers 5 from sticking as described above, the mold is cleaned regularly, but this mold cleaning is done by taking the mold off the production line and puffing the solder plating on the mold. The method was to mechanically remove it with a cloth or the like.

[Problem to be solved by the invention]

In the conventional semiconductor device manufacturing method, since the molding process is performed through the steps described above, solder whiskers 5 occur,
This caused a problem in that the external leads 4 were connected to each other.

In addition, since the molds are cleaned regularly, the production line is stopped for a long time, resulting in poor production efficiency.

The present invention was made to solve the above-mentioned problems, and provides a method for manufacturing a semiconductor device that prevents the generation of solder whiskers and improves production efficiency.

[Means to solve the problem]

In the method for manufacturing a semiconductor device according to the present invention, during the molding process of an external lead, a dummy semiconductor device having an external lead plated with a plating material different from an exterior plating material applied to the external lead is formed during the molding process. The dummy semiconductor device is inserted between semiconductor devices during the mass production process, and the external leads of this dummy semiconductor device are formed.

[Effect]

In this invention, during the process of molding the external leads of a semiconductor device, a dummy semiconductor device with external leads coated with a plating material different from the exterior plating material is inserted between regular semiconductor devices in order to remove solder whiskers. The adhesion between the solder plating on the external leads of the dummy semiconductor device and the solder plating on the external leads during the mass production process is stronger than the adhesion between the processing mold and the solder plating on the external leads during the mass production process. Because of this, when the processing mold is crimped onto the external lead of the dummy semiconductor device during the external lead molding process, foreign matter such as solder plating scraps attached to the processing mold must be peeled off from the processing mold. Therefore, foreign matter does not adhere to the external leads of the semiconductor device during the mass production process.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

In FIGS. 1(a) to (d), the same reference numerals as in FIG. A foreign substance attached to the punch 1, for example, Ag plating is applied.

Next, a process for forming the external leads 4 of the semiconductor device will be explained.

FIG. 1(a) shows the solder-plated external lead 4 in a molded state. From this figure, it can be seen that the solder whiskers 5 have grown significantly. If the molding operation is continued while the solder whiskers 5 remain large as described above, the solder whiskers 5 on the side surface of the punch 1 will be stuck to the outer leads 4, causing a seal between the outer leads 4. Therefore, Fig. 1(b)-(
As shown in d), by inserting and molding an external lead 6 plated with Ag, which is different from the plating of the external lead 4, during the mass production process, the solder whiskers 5 on the side surface of the punch 1 are formed by this external lead. It is possible to stick to 6 and completely remove it. For this reason, it is possible to form the external lead 4 without any adhesion of the solder whiskers 5 in a normal mass-produced product.

The frequency at which the external leads 6 coated with Ag plating, which is different from the plating of the external leads 4, is inserted into the normal mass production process and molded may be determined at an appropriate interval depending on the processing conditions and the like.

In addition, in the above embodiment, when the exterior plating is solder,
Ag is used to remove foreign matter attached to punch 1, etc.
Although the case where a plated external lead 6 is used is shown, any type of exterior plating may be used, and in short, a different type of plating is applied so that the solder hair 5 etc. attached to the punch 1 etc. can be peeled off and removed. If this is the case, the same effects as in the above embodiment can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, during the molding process of the external lead, a dummy semiconductor device having the external lead plated with a plating material different from the exterior plating material applied to the external lead is formed during the molding process. This dummy semiconductor device is inserted between semiconductor devices during the mass production process, and the external leads of this dummy semiconductor device are molded to remove foreign matter attached to the processing mold, so solder whiskers etc. attached to the processing mold are removed. The foreign matter adheres to the external leads of the dummy semiconductor device and is removed. Therefore, if these dummy semiconductor devices are inserted at appropriate intervals depending on the processing conditions, solder whiskers will not stick to the external leads during the normal mass production process, and the dummy semiconductor devices inserted at the required intervals during the molding process will The external lead removes solder whiskers that adhere to the processing die during molding.

Therefore, there is an effect that a high-yield, high-quality semiconductor device can be manufactured at low cost without any problems such as short-circuiting between external leads.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view for explaining an embodiment of the method for manufacturing a semiconductor device according to B's invention, FIG. 2 is a perspective view of a general semiconductor device with molded external leads, and FIG. 3 4 is a cross-sectional view for explaining a conventional method of manufacturing a semiconductor device, and FIG. 4 is an enlarged perspective view of the conventional semiconductor device showing a state in which solder whiskers are fixed to external leads. In the figure, 1 is a punch, 2 is a bending pin, 3 is a semiconductor device, 4 is an external lead, 5 is a solder beard, and 6 is an external lead plated with Ag. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent: Masuo Oiwa (2 others) Figure 1 Figure 1 Figure 1 Figure Figure Figure Figure

Claims (1)

[Claims] Supplying semiconductor devices with external leads at predetermined intervals,
In the manufacturing process of a semiconductor device in which the external lead is molded into a desired shape, a dummy is provided with an external lead plated with a plating material different from an exterior plating material applied to the external lead during the molding process of the external lead. A semiconductor device characterized in that the semiconductor device is inserted between the semiconductor devices in the mass production process during the molding process, and the external leads of the dummy semiconductor device are molded to remove foreign matter attached to the processing mold. Method of manufacturing the device.