Shock Alert -- Electrostatic Discharge Testing

Touch­ing some­one or some­thing and receiv­ing a ​“shock” can be quite shock­ing. Elec­tro­sta­t­ic Dis­charge (ESD) occurs when a sud­den elec­tric cur­rent flows between two objects. ESD can cause dam­age to elec­tri­cal devices, as well as poten­tial equip­ment fail­ure and net­work down­time, which can lead to sig­nif­i­cant pro­duc­tion loss­es. Every man­u­fac­tur­er must be aware of ESD dur­ing equip­ment design, and needs to estab­lish a pro­tec­tive area free of sta­t­ic to reduce the chance of ESD occur­ring. The tech­ni­cal require­ments of a design deter­mine which ESD test­ing stan­dards should be select­ed, and the oper­a­tor must under­stand the dif­fer­ences between device-lev­el and sys­tem-lev­el testing.

The most com­mon mod­el for ESD test­ing is the Human Body Mod­el (HBM) device-lev­el test. If a human dragged his feet across a car­pet, unaware of the charge he was cre­at­ing, and then touched an elec­tron­ic device, he would have cre­at­ed ESD. This mod­el sim­u­lates this type of elec­tron­ic dis­charge from a human, and deter­mines how sus­cep­ti­ble the par­tic­u­lar com­po­nent is to ESD damage. 

Machine-Mod­el (MM) device-lev­el test­ing involves indus­tri­al automa­tion man­u­fac­tur­ing sites. Machines that become elec­tri­cal­ly charged after being turned on and dis­charge into an elec­tron­ic com­po­nent after mak­ing con­tact were test­ed for an ESD event.

Charged-Device Mod­el (CDM) device-lev­el test­ing sim­u­lates fre­quent sit­u­a­tions in auto­mat­ed man­u­fac­tur­ing envi­ron­ments in which machines are turned on and left on for an indef­i­nite peri­od of time. This caus­es a buildup of elec­tric charges, and when a part comes in con­tact with an uncharged con­duc­tor, the dis­charge occurs. 

ESD Immu­ni­ty test­ing is a sys­tem-lev­el test that sim­u­lates the ESD of a human on an elec­tron­ic com­po­nent. An ESD gen­er­a­tor sends ESD puls­es to the equip­ment either by direct phys­i­cal con­tact or through the air.

EFT Immu­ni­ty sys­tem-lev­el test, also known as burst-immu­ni­ty, sim­u­lates sit­u­a­tions in typ­i­cal envi­ron­ments. It is per­formed on all pow­er, sig­nal, and earth wires. The burst con­sti­tutes a sequence of puls­es with­in a defined amount of time. 

Surge Immu­ni­ty, or light­ning test, is the most severe test in pow­er and time. It sim­u­lates direct light­ning strikes, induced cur­rents due to indi­rect light­ning strikes, or switch­ing pow­er systems.

Sev­er­al com­pa­nies have devel­oped equip­ment for use in ESD test­ing. Teseq offers five dif­fer­ent ESD sim­u­la­tors, ful­fill­ing all require­ments of the major ESD stan­dards. Each of the sim­u­la­tors is designed for use in Immu­ni­ty Test­ing, and have dif­fer­ent com­pli­ance and kV spec­i­fi­ca­tions. Trek designed test and audit equip­ment for spe­cif­ic ESD test­ing, like mate­r­i­al dis­si­pa­tion test­ing and sta­t­ic charge mon­i­tor­ing. HV Tech­nolo­gies offers the Mod­el ESD 3000, a ful­ly auto­mat­ed and pro­gram­ma­ble ESD simulator.

Regard­less of which tests are run or which equip­ment is used, oper­a­tors must per­form a final elec­tro­mag­net­ic inter­fer­ence test and a test of the pro­tec­tion circuit.

For more infor­ma­tion, con­tact Robots​.com online or at 877−762−6881.