JPH10178120A - Method for static elimination of resin-encapsulated semiconductor device - Google Patents

Abstract

An object of the present invention is to provide a method for static elimination of a resin-encapsulated semiconductor device, wherein static elimination in a semiconductor device manufacturing process is effectively performed. SOLUTION: This is a manufacturing process of a resin-encapsulated semiconductor device sealed with a mold resin having a characteristic that a volume resistivity is inversely proportional to a temperature, and heat-treats the entire semiconductor device to accumulate in a package of the semiconductor device. Removed static electricity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a static elimination method for removing static electricity accumulated in a semiconductor device package in a process of manufacturing a resin-encapsulated semiconductor device.

[0002]

2. Description of the Related Art Conventionally, a resin-encapsulated semiconductor device is configured, for example, as shown in FIG. In FIG. 2, a semiconductor device 1 is a so-called resin-encapsulated semiconductor device and includes a lead frame 2 including a die pad on which a semiconductor element is mounted.
A semiconductor element 3 mounted on the lead frame 2,
A resin molding resin 4 is formed to cover the entirety of the lead frame 2 and the semiconductor element 3.

The lead frame 2 has a substantially rectangular semiconductor element mounting surface, for example.

The semiconductor element 3 is mounted on a lead frame 2 via a silver paste 5 and is fixedly held by so-called die bonding.

The molding resin 4 is made of, for example, an epoxy resin or the like.
Is formed so as to cover the airtight.

The resin-sealed semiconductor device 1 having such a configuration
According to this, the semiconductor element 3 is mounted on the lead frame 2 and sealed with the mold resin 4 so as to be protected from the outside.

[0007]

By the way, the resin-encapsulated semiconductor device 1 configured as described above has, in its manufacturing process, a process in which static electricity is easily generated due to, for example, friction or peeling between insulators. The occurrence of defects in semiconductor devices due to such static electricity has become a problem. As a countermeasure against this static electricity, conventionally, for example, an ionizer is used or humidity control by humidification is performed to suppress the generation of static electricity. When an ionizer is used, there is a problem that it is difficult to maintain and control the static elimination by the ionizer because of the danger of reverse charging by the ionizer.

In the case of humidity control by humidification, dew condensation occurs due to humidification, and metal erosion may occur on device parts of the semiconductor device due to the influence of mist due to the dew condensation. In addition, the moisture absorbed by the mold resin 4 which is a package of the semiconductor device causes the absorbed moisture to become steam and expand, whereby the semiconductor element 3 and the lead frame 2 are separated from each other and the lead frame 2 is bent. As a result, there is a problem that stress acts on the mold resin 4 and cracks are easily generated in the mold resin 4 corresponding to the vicinity of the corner of the lead frame 2.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a method for removing static electricity from a resin-encapsulated semiconductor device, which effectively removes static electricity in a semiconductor device manufacturing process.

[0010]

According to the present invention, there is provided a process for producing a resin-encapsulated semiconductor device which is encapsulated with a mold resin having a characteristic that a volume resistivity is inversely proportional to a temperature. This is achieved by a method for removing static electricity in a resin-sealed semiconductor device, in which static electricity accumulated in a package of the semiconductor device is removed by heat-treating the entire semiconductor device.

According to the above structure, the heat resistance of the entire semiconductor device causes the volume resistivity of the mold resin, for example, the epoxy resin, which constitutes the outer shape of the package of the semiconductor device to decrease due to the temperature change. , And the moving speed of the charge is increased. As a result, the electric charge accumulated in the semiconductor device moves to the outside along a surface of the mold resin through a place having a low potential, for example, a so-called outer lead projecting outside from the mold resin.

In addition, the heat treatment causes the moisture in the mold resin to evaporate due to the moisture absorption of the mold resin, and the electric charge accumulated in the semiconductor device is released to the atmosphere together with the water vapor. Become. Therefore, the charge stored in the semiconductor device is removed by the above-described charge transfer to the outside and charge release to the atmosphere, and the charge of the semiconductor device is removed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIG. The embodiment described below is a preferred specific example of the present invention, and thus various technically preferable limitations are added. However, the scope of the present invention particularly limits the present invention in the following description. The embodiment is not limited to these embodiments unless otherwise stated.

FIG. 1 is a graph showing a static elimination state according to an embodiment of a static elimination method for a resin-sealed semiconductor device according to the present invention. This method for removing static electricity from a resin-encapsulated semiconductor device is performed by removing the resin-encapsulated semiconductor device 1 shown in FIG. 2 during a manufacturing process, for example, after a process in which static electricity is likely to be generated due to friction or separation between insulators. For example, it is carried out by housing it in an oven, a heating furnace or the like and heating it at a predetermined set temperature. FIG. 1 shows that, for example, 100
6 is a graph showing the relationship between the charge amount and the heat treatment time when a resin-encapsulated semiconductor device charged to a charge amount of about 0 V is heat-treated at various temperatures.

First, a characteristic curve A shows a case where the apparatus is left at room temperature (23.7 ° C.) for reference. In this case, the charge is not substantially removed even after 30 minutes have passed. The characteristic curve B indicates that the set temperature is 50 in the oven.
The case where it heat-processed at ° C is shown. In this case, the change over time of the charge amount is almost the same as the characteristic curve A when left at room temperature, and the charge is not substantially removed.

Next, a characteristic curve C shows a case where the heat treatment is performed at a set temperature of 100 ° C. in an oven. In this case, the charge amount is reduced to half or less after 10 minutes, and
After one minute, it will drop to about 1/3 or less,
The static elimination is performed more effectively than the characteristic curves A and B.

A characteristic curve D shows a case where the heat treatment is performed at a set temperature of 125 ° C. in an oven. In this case, the charge amount is reduced to about 1/3 after elapse of 5 minutes, becomes about 1/10 after elapse of 10 minutes, and is almost completely eliminated after elapse of 20 minutes.

A characteristic curve E shows a case where the heat treatment is performed at a set temperature of 150 ° C. in an oven. In this case, the charge amount is almost completely eliminated after the lapse of 5 minutes.

Therefore, in the present embodiment, when the charge of the resin-encapsulated semiconductor device 1 is removed, it is necessary to set the charge amount to at least about 1/3 after 30 minutes of heating.
It is preferable that the heating is performed at a temperature of 100 ° C. or higher by a heating means.

Here, it is considered that the charge removal is performed as follows. That is, when the entire semiconductor device 1 is heat-treated, the volume resistivity of the mold resin 4, for example, the epoxy resin, which forms the package outer shape of the semiconductor device 1 is reduced by the temperature change. Therefore, due to the decrease in the volume resistivity, the amount of moving charges per unit time increases, and the moving speed of the charges increases. As a result, the electric charges accumulated in the semiconductor device 1 move to the outside along the surface of the mold resin 4 via a place having a low potential, for example, a so-called outer lead projecting outside from the mold resin.

Further, in addition to the charge transfer described above, the heat treatment causes the moisture in the mold resin to evaporate due to the moisture absorption of the mold resin 4, and together with this water vapor,
The charges accumulated in the semiconductor device 1 are released to the atmosphere. Thus, the charge stored in the semiconductor device 1 is removed by the charge transfer to the outside and the charge discharge to the atmosphere, and the charge of the semiconductor device 1 is removed.

The semiconductor device 1 thus neutralized
In this method, since the occurrence of defects due to static electricity accumulated in the semiconductor device 1 is eliminated, the production yield of the semiconductor device 1 is improved, and the productivity is improved and the cost is reduced. become.

In the above-described embodiment, as the semiconductor device to be heat-treated, a resin seal configured to cover the lead frame 2 and the semiconductor element 3 mounted thereon with the mold resin 4 shown in FIG. Although the static elimination method has been described with respect to the static semiconductor device 1, it is apparent that the static elimination method according to the present invention can be applied not only to this but also to package type semiconductor devices having other configurations.

[0024]

As described above, when the entire semiconductor device is subjected to the heat treatment, the charge accumulated in the semiconductor device is removed by the charge transfer to the outside and the charge discharge to the atmosphere. The static elimination of the semiconductor device is performed, and occurrence of a defect due to static electricity in a semiconductor device manufacturing process is eliminated. Thus, according to the present invention, it is possible to provide a static elimination method for a resin-encapsulated semiconductor device in which static elimination in a semiconductor device manufacturing process is effectively performed.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a main part of a first embodiment of a resin-sealed semiconductor device having a lead frame according to the present invention, excluding a molding resin.

FIG. 2 is a schematic sectional view showing an example of a conventional resin-encapsulated semiconductor device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Resin sealing type semiconductor device, 2 ... Lead frame, 3 ... Semiconductor element, 4 ... Mold resin, 5
..Silver paste.

Claims (2)

[Claims] 1. A manufacturing process of a resin-sealed semiconductor device sealed with a mold resin having a characteristic that a volume resistivity is inversely proportional to a temperature, wherein a heat treatment is performed on the entire semiconductor device to form a package of the semiconductor device. A static elimination method for a resin-encapsulated semiconductor device, wherein static electricity accumulated in a semiconductor device is removed. 2. The static elimination method according to claim 1, wherein the heat treatment is performed at a temperature of 100 ° C. or higher.