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Electrostatic Discharge Tester

IP.com Disclosure Number: IPCOM000087319D
Original Publication Date: 1977-Jan-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 3 page(s) / 41K

Publishing Venue

IBM

Related People

Madzy, TM: AUTHOR [+3]

Abstract

Under certain conditions, electrostatic discharges (ESDs) from people can cause catastrophic failure (destruction) of various integrated circuit (IC) devices. Some devices (field-effect transistors (FETs)) are particularly susceptible to damage because of the relatively low destruction breakdown voltage (50 to 100 volts) of their thin gate oxides. 0ne significant source of concern is ESD from the human body during handling.

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Electrostatic Discharge Tester

Under certain conditions, electrostatic discharges (ESDs) from people can cause catastrophic failure (destruction) of various integrated circuit (IC) devices. Some devices (field-effect transistors (FETs)) are particularly susceptible to damage because of the relatively low destruction breakdown voltage (50 to 100 volts) of their thin gate oxides. 0ne significant source of concern is ESD from the human body during handling.

The effectiveness of the protective device used on FETs has previously been measured by pulsing the input with a 100 nanosecond wide voltage pulse and varying its amplitude until a destruction occurs. This is a relative test and has no absolute relationship to a charge that occurs during actual personnel handling. This tester has been developed to provide absolute destruction levels. It contains an RC circuit which simulates the human body.

The capacitance of the human body holding some charge voltage (Vp) is represented by Cp. The value of this capacitance ranges between 100 and 200 pF with an average value being 150 pF. The body and contact resistances are given by Rp and can range upward from 1000 ohms, with a value of 2000 or higher being most common.

The tester has the capability of testing devices by injecting voltage between any two pins, or group of pins, or by injecting into one pin with the return path being capacitively coupled to a ground plane on the tester.

Under normal testing conditions, only the single cycle function governed by switch SW1 is used. However, a variable frequency oscillator 3, 1-100 Hz, is provided for initial setup and special testing. Selection between the oscillator 3 and switch SW1 is by a switch SW2.

When point A goes to ground, single-shots 5 and 7...