Junction Damage: Sources



Junction Damage: Sources (What generated the voltage spike?)
Humans	Description	Investigate
Humans	Handling by un-grounded personnel	Insufficient training or certificate program Uncontrolled work flows / processes Current procedures or practices not ESD compliant
Machine	Design	PCB design and layout with ESD suppression
	Improperly grounded	All components contacting IC or PCBs must be conductive and connected to ground All components contacting IC or PCBs must be conductive and equi-potential to ground (ie. Phenolic spacers in a handler; Suspect any non-metallic piece Soldering Irons (ie. Too high resistance of tip to ground; Three prong electrical plug.
	Ground bounce sources	Switching relays
	Field Inductance or EMI	Arcing; CRT related items; Electric motors; Microwave sources, RF sources
Cleanliness of raw power supply
	Noisy supply from external supplier	Monitor Electric utility
	Network load variations	Ground bounce sources; Voltage Supply harmonics; Switching relays
Environment
	Weather	Lightning strikes; Low humidity (<40RH)
	Triboelectric materials	Non-conductive table tops, wall panels, floor. Packing & transport materials. Styrofoam coffee cups.
	Resistive ground references	ESD ground common with facility ground
Manufacturing defects
	Inherent design weakness	circuit design; layout
	Silicon defect	crystalline; particulates