1 Version01_  Triboelectric charging occurs when two materials make contact and separate  Electrons from one material are transferred to another leaving one positively charged and the other negatively charged. –The nature of the materials will determine who losses or gains electrons  The build up of static electricity is determined by several factors such as: area of contact, the speed of separation, relative humidity, and chemistry of the materials, surface work function, etc. *Table from ESDA What is ESD and where does it come from? – Triboelectric Charging

2 Version01_ ESD Standards – Human Body Model, MIL-STD  Based on Skin-to-Metal Contact –e.g. Person touches pin of IC, discharging directly to pins  Used in Military Standard (883E) test specification  Addresses the Manufacturing/Production environment; testing is done directly on the IC  Circuit Model: Discharge Voltage Peak Current 500V 0.33A 1,000V 0.67A 2,000V 1.33A 4,000V 2.67A 8,000V 5.33A

3 Version01_  Based on Metal-to-Metal Contact –e.g. Person with tool/key in hand discharges to I/O port  Used in IEC test specification  Addresses the user-environment; testing is done at the application or system level  Circuit Model: Discharge Voltage Peak Current 2,000V 7.5A 4,000V 15.0A 6,000V 22.5A 8,000V 30.0A ESD Standards – IEC

4 Version01_ IEC , continued Discharge Voltage First PeakCurrent, 30nsCurrent, 60ns 2,000 V 7.5 A 4 A 2 A 4,000 V 15.0 A 8 A 4 A 6,000 V 22.5 A 12 A 6 A 8,000 V 30.0 A 16 A 8 A Specified current values, per discharge voltage Most all manufacturers test to 8kV or higher! ESD Standards – IEC Waveform

5 Version01_ Peak current Discharge VoltageHuman Body ModelIEC V 0.33 A 1,000 V 0.67 A 2,000 V 1.33 A 7.5 A 4,000 V 2.67 A 15.0 A 8,000 V 5.33A 30.0 A  The key here is that a chipset that survives Human Body Model testing (in the manufacturing environment) is not guaranteed to survive in the field, where the exposure to ESD will be much more severe.  Different models yield much different peak current values; ultimately electrical stresses on the chipset are very different.  ESD levels in the field far exceed the values that can be generated in the manufacturing environment. Comparing the Two Specifications – IEC vs. Human Body Model