JPH03133167A - Protecting circuit of electronic parts - Google Patents

Abstract

PURPOSE:To improve the function for protecting electronic parts from electrostatic breakdown, by discharging electrostatic charge applied to the contact part of a connector to power supply lines of electronic parts connected with the contact part via a signal line. CONSTITUTION:The following are provided; resistors 4 inserted in signal wires connecting between contact parts 3a of a connector 3 and electronic parts 1, and diodes 5, 6 connecting the signal lines 2 and power supply lines 7, 8 of the electronic parts 1 between the resistors 4 and the contact parts 3a. That is, the following method is not used; by surrounding the contact part 3a of the connector 3 in order to prevent a hand from touching the parts, electrostatic charge is prevented from being applied to the electronic parts 1. Instead, by discharging the electrostatic charge applied on the contact part 3a to the power supply lines 7, 8, electrostatic charge are prevented from being applied on the electronic parts 1. Thereby the electronic parts 1 can electrically be protected from electrostatic breakdown.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a protection circuit for electronic components, and is particularly suitable for use in protecting electronic components from damage caused by static electricity.

(Prior art) Semiconductor devices such as integrated circuits may be damaged if high voltage or high current exceeding a predetermined value is applied.
When inspecting or adjusting equipment in which integrated circuits are used, care must be taken to ensure that high voltages are not applied to the integrated circuits.

By the way, static electricity generated by nylon clothing and the like may be accumulated in the human body.

This accumulated static electricity is discharged when a person touches a conductor, but the discharged static electricity may destroy the integrated circuit. In order to prevent such inconveniences, electronic components such as connector contacts, which are exposed to the outside and may be touched by people, and which are expected to be damaged by electrostatic discharge, are placed in the contact area. Conventionally, when the contact part is connected to the electronic part, the contact part is surrounded by a metal case, and the metal case is connected to the frame ground to prevent the electronic part from being damaged by electrostatic discharge.

<Problem to be solved by the invention> However, such a metal case must be formed into a shape that matches the shape of the connector and the state in which the connector is used, so the shape may have to be formed in a complicated manner. In many cases, there was a problem of high production costs. In addition, there is a problem that mounting efficiency of various parts is reduced due to the need for a large installation space, and it is difficult to completely prevent people from touching the contact parts, so the reliability of preventing electrostatic damage is reduced. There were some bad issues.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to improve the reliability of a machine that protects electronic components from electrostatic damage and to enable inexpensive manufacturing.

<Means for Solving the Problems> A protection circuit for an electronic component of the present invention includes a resistor interposed in a signal line connecting between a contact portion of a connector and an electronic component, and the resistor and the contact. A diode is provided for connecting the signal line and the power supply line of the electrical component between the contact part, so that static electricity applied to the contact part is discharged to the power supply line through the diode.

Function> Instead of surrounding the contact part of the connector so that it cannot be touched by hands to prevent static electricity from being applied to electronic components, the method is to discharge the static electricity applied to the contact part to the power line. Prevent static electricity from being applied to the electronic components. Therefore, it is possible to electrically protect the electronic components from being destroyed by static electricity.

<Embodiment> In Figure 0, which is a circuit diagram of a main part of a protection circuit for an electronic component showing an embodiment of the present invention, l is a large-scale integrated circuit, etc.
This electronic component 1 has a plurality of terminals, each of which is connected to a contact portion 3a of a connector 3 via a signal line 2.

This connector 3 is used in a position where it can be opened and closed, and the other party to be connected is provided on the load side 10 in the same device, and the contact portion is exposed to the outside when in the open state. Therefore, if the connector 3 is open, there is a possibility that a human fingertip may touch the contact portion 3a connected to the electronic component 1. In the embodiment, even if the static electricity charged on the human body is discharged to the contact portion 3a by touching the human fingertip, the electronic component l
is protected from being destroyed.

That is, a resistor 4 is interposed in each signal line 2 connecting the electronic component 1 and the contact portion 3a. Further, each signal line 2 and the positive power supply line 7 are connected through a diode 5 between the resistor 4 and the contact portion 3a. Similarly, each signal line 2 and a negative power supply line 8 are connected through a diode 6. With this configuration, static electricity applied to the contact portion 3a is removed by the diode 5.6.
is discharged through the power supply line 7.8. Therefore, it is possible to reliably prevent an accident in which the electronic component 1 is damaged by static electricity due to the application of static electricity. In order to confirm the effect of this protection circuit, for example, a resistor of tens to hundreds of ohms is connected and diodes 5 and 6 for switching and having a short reverse recovery time are used to configure the protection circuit. Then, an experiment was conducted in which 25 KV of electrostatic noise generated by an electrostatic noise generator was applied to the contact portion 3a. As a result, even when such high-voltage electrostatic noise was applied, no electrostatic damage to the electronic component 1 was observed, confirming that the protection circuit was working effectively.

<Effects of the Invention> As described above, the present invention discharges static electricity applied to the contact portion of the connector to the power line of the electronic component connected to the contact portion via the signal line. Even if static electricity is applied to the contact portion, the electronic component can be reliably protected from being destroyed by static electricity. Therefore, the reliability of protecting the electronic components from electrostatic damage can be improved, and the need for a metal case to prevent human fingertips from touching the contact parts can be eliminated. , it is possible to reduce manufacturing costs and improve mounting efficiency.

[Brief explanation of the drawing]

The figure is a circuit diagram of a main part of a protection circuit for an electronic component showing an embodiment of the present invention. 1...Electronic components, 2...Signal lines, 3...Connectors. 3a... Contact portion, 4... Resistor. 5.6...Diode, 7...Positive power line. 8... Negative power line.

Claims (1)

[Claims] A resistor interposed in a signal line connecting between the contact portion of the connector and the electronic component; A protection circuit for an electronic component, comprising: a diode connected to a power line, and static electricity applied to the contact portion is discharged to the power line through the diode.