JPS5816549A - Housing for semiconductor device - Google Patents

Abstract

PURPOSE:To allow static charges induced on the surface of a device package to escape by a method wherein the surface of a semiconductor device housing is rendered electroconductive except the regions surrounding the leads. CONSTITUTION:The entire surface 13 or a part thereof of a semiconductor device housing is rendered electroconductive except the locations surrounding external terminals (leads) 12. Static charges generated by fricition the housing experiences with air, casings, or other devices cannot accumulate on the housing, the housing surface constituting a good conductor for the static charges to leak through.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface of a container (hereinafter referred to as a package) for a semiconductor device.

The package consists of external terminals (hereinafter referred to as leads) that take out the electrodes formed on the semiconductor device (hereinafter referred to as the semiconductor chip) to the outside, and a material that electrically insulates between the leads, thereby isolating the chip from the external environment. .

The packaging material is usually metal or ceramic.

Glass or plastic resin is used.

In the case of a metal package, the leads are insulated by glass.

In the case of ceramic ivy, glass, and plastic resin, the outer surface of the package, excluding the leads, is made of insulating material. An important factor in selecting these materials is electrical insulation between the leads. On the other hand, a package induces static electricity on the surface of the package due to contact with the external environment of the package, that is, air, or contact with a container (hereinafter referred to as a case) housing the package, friction, or the like. The more insulating the package material is, the more the static charge will be dissipated and the higher the voltage will be.

In semiconductor devices, especially MO8 semiconductor devices, the elements are formed of extremely thin insulating layers, and the high voltage generated by the static electricity causes destruction of the elements. To avoid this failure, an electrostatic protection circuit is usually installed on the chip, and at the same time, a conductive material is selected for the case that houses the device. For example, in the case of MO8 semiconductor device,
The electrostatic breakdown voltage is 200 to 300v.

Among the package materials, the resistance of ceramic is 1014g.
・It has a specific resistance that is higher than the average value, and is 10 to 10 Ω for epoxy resin and silicone resin.

Package materials tend to have higher resistance values to improve insulation or protect chips from impurities. In particular, if the resistivity exceeds 1011, it may cause friction with the air or damage to the case when handling the semiconductor device.
Otherwise, static electricity of several thousand volts can easily be generated due to friction with other devices.

If the material that rubs against the package is metal, the voltage can be kept lower than if it is an insulator, but the voltage will be 300 to 1000V.

In order to eliminate this defect, the present invention attempts to suppress static charges induced on the package surface by applying conductive treatment to the area of the package surface other than the area around the leads.

By conducting conductive treatment on the package surface, static charges generated by friction with air or J11 wires with the case or other devices easily leak through the discharge path on the package surface and do not charge up.

As a method of conductive treatment, for example, metal can be vapor-deposited. Another method is to apply a surfactant aqueous solution,
After that, by drying, a parent wood base can be attached to one surface. As another method, it is also possible to apply rubber or resin mixed with metal microspheres. Alternatively, a metallic adhesive tape can be used.

The conductive treatment is applied to a part or all of the package surface area excluding the area around the leads.

FIGS. 1 and 2 show an example of a region to be subjected to conductive treatment.

It is also possible to remove the conductive treatment before mounting the semiconductor device on a socket or wiring board. For example, if metal is vapor-deposited, it is washed off with an acid such as hydrochloric acid, or if treated with a surfactant, it is washed with water to wash away the hydrophilic groups attached to the surface.

If rubber, l/m fat, etc. are applied, wash them off with an organic solvent, etc. When a semiconductor device is mounted, it is generally desirable to remove the conductive treatment on the package surface and restore the package to an insulating state.

[Brief explanation of the drawing]

FIG. 1 shows a container (front side) of a semiconductor device according to an embodiment of the present invention.
A perspective view of. 11 Resin 12 Lead 13 Area subjected to conductive treatment FIG. 2 is a perspective view of a container (back side) of a semiconductor device according to another embodiment of the present invention. 21 Resin 22 Lead 23 Area subjected to conductive treatment. Figure 1 Ward Z

Claims (1)

[Claims] A semiconductor device container in which the surface area of the semiconductor device container, excluding the area around the external terminals, has been subjected to conductive treatment.