JPS6237841B2 - - Google Patents

Description

Detailed Description of the Invention The present invention provides electrostatic distributed capacitance by intersecting a plurality of metal plates electrically insulated from the ground at the center, and after charging the plates with an electric charge, In an electrostatic generator that discharges electric charge to the device under test when a switch is turned on, the opening between two of the crossed metal plates is connected to the surface of the casing of the device under test. The purpose of this is to maximize the discharge current and electric field strength.

Generally, when a person with an electrical charge on their body touches an electronic device, the electrical charge discharges into the electronic device, causing electrostatic damage that can cause the electronic device to malfunction or destroy electronic elements and parts. Static electricity generators are used as a kind of pseudo-noise generator to reproduce electrostatic disturbances in order to improve the reliability of electronic equipment and prevent accidents. Static electricity generators apply voltage to a capacitor with opposing parallel metal plates as electrodes to accumulate charge, and connect one electrode to the earth or floor and the other electrode to an electronic device to release the charge in the capacitor. A method of rapidly discharging the metal, or by intersecting multiple metal plates approximately at the center and insulating the metal plates from the ground or floor, applying a voltage to the distributed capacitance between the ground or the floor and storing electric charge.
There is a method of attaching a switch to a part of the plurality of metal plates, bringing it into contact with the electronic device under test, and turning the switch on and off to continuously flow a high-frequency attenuated current to the device under test. However, the latter method, which uses multiple metal plates that intersect at approximately the center, utilizes the capacitance distributed in the ground and space, so it is possible to generate a radiated electric field strength component in the space, and it is possible to generate static electricity noise similar to human body discharge. In addition to being able to generate
It is widely used because it has the characteristic of allowing a large discharge current to flow at a low voltage.

Conventionally, a discharge device for discharging the charge of a static electricity generator using a plurality of metal plates to an electronic device under test is mounted on a control panel 2 made of an insulating material, as shown in FIGS. 1 and 2. For example, a switch 3 is attached to the tip of one of the metal plates 1a in a combination of four metal plates 1, and the needle lead wire 5 provided on the switch 3 is brought into contact with the casing of the electronic device 4, and the switch is activated. was turned on to discharge electricity.
In this case, the needle-shaped lead wire 5 of the metal plate 1a to which the switch 3 is attached is oriented perpendicularly to the surface of the casing of the electronic device 4 to cause discharge. With this structure, electric discharge is applied to the metal plate 4 as shown in Fig. 3, and the center P of the cross is maintained while the metal plate 1 of the cross is kept parallel to the ground or floor.
The discharge current and electric field strength were measured by changing the position facing the metal plate 4 around the point.
Figure 4 shows the measurement results.
The horizontal axis indicates the angle θ in the direction of the cross-shaped metal plate, with the horizontal axis representing the angle θ in the direction of the cross-shaped metal plate at 0°, 90°, 180°, 270°, and 360°. If we draw a characteristic curve with the discharge current I [A] as the vertical axis, the curves will be 45°, 135°, and 135° as shown in Figure 4a.
Peak values appear at angles of 225° and 315°. Similarly, if we measure the electric field strength E [dB] generated in space over a 360° distance from a distance of 2 m from point P, and plot it on the vertical axis, we can see that it is 45°, 135° as shown in Figure 4b.
It can be seen that the maximum electric field strength is in the four directions of ゜, 225゜, and 315゜. Therefore, this angle corresponds to when the metal plate to be discharged, that is, the metal surface of the electronic device, and the opening surface of the two metal plates of the cross-shaped metal plate of the static electricity generator are placed opposite to each other. In the conventional method, the surface of one metal plate is placed opposite to the plate to be metallized, so it has the disadvantage of using the metal plate at a position where both discharge current and electric field strength are minimum. This was also confirmed from the experimental results.

The present invention eliminates such drawbacks of the conventional art, and the discharge current,
2 of multiple metal plates that maximizes the electric field strength
The present invention relates to a discharge device for a static electricity generator that discharges electricity by arranging the openings between the plates so as to face the electronic device under test.

As shown in the embodiment of FIG. 5, the electrostatic generator discharge device of the present invention has the opening surfaces of the two metal plates 1a and 1b of the cross-shaped metal plate 1 positioned opposite to each other in the direction of the electrical equipment 4, By providing a switch 3 on one of the two metal plates 1a and 1b, for example 1a, and turning it on, the charge charged in the metal plate is discharged in a state where maximum current and maximum electric field strength are obtained. Furthermore, since the same characteristics can be obtained at a lower voltage than with conventional discharge methods, dangers due to high voltage can be prevented. In this embodiment, a cross-shaped metal plate 1 consisting of four metal plates 1 has been described, but the same effect can be obtained even if the number of metal plates 1 is increased.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional discharge device, Fig. 2 is its plan layout, Fig. 3 is a perspective view showing the measurement state of characteristics in discharge, Fig. 4 is a measurement curve diagram in Fig. 3, and a is 5 is a curve diagram showing the relationship between angle and discharge current, b is a curve diagram showing the relationship between angle and electric field strength, and FIG. 5 is a plan layout diagram of the discharge device of the present invention. In the figure, 1: metal plate, 2: control panel, 3: switch, 4: electronic device, 5: needle lead wire.

Claims (1)

[Claims] 1 After charging a plurality of metal plates that are electrically insulated from the earth or floor and crossed in the center, a switch installed on the metal plate causes the electric charge to be discharged to the device under test. A discharge device for an electrostatic generator, characterized in that the two opening surfaces of the intersecting metal plates are arranged to face the surface of a casing of a device under test.