ESD (Electrostatic Discharge)

Electrostatic discharge (ESD) is the rapid transfer of static charge between two objects at different electrical potentials. To a technician it is the spark you feel touching a doorknob, but to integrated circuits it is a high-current event that can puncture gate oxides, fuse tiny interconnects, or leave behind latent damage that fails weeks later. The danger is that the threshold for damaging modern semiconductors is far below the roughly 3,500 V a person can actually feel, so harmful events are invisible to the operator.

Models and thresholds

Engineers characterize ESD with several models. The Human Body Model (HBM) represents a charged person discharging through a device, with typical qualification levels around a couple of kilovolts. The Charged Device Model (CDM) represents a charged component discharging through one of its own pins; it is a much faster event and often damages parts at voltages ten to twenty times lower than HBM, sometimes around 100 to 150 V. Some advanced packages are now qualified at 250 V HBM or below.

Working ESD-safe

Protection is about controlling charge, not luck. A grounded wrist strap bonds the technician to the same potential as the work, an ESD mat and grounded tools drain charge safely, and conductive or dissipative packaging shields parts in transit. Where insulators cannot be grounded, ionizers neutralize the charge, and keeping relative humidity above roughly 40% reduces static buildup.

For anyone opening a Bitcoin miner to work on a hashboard or the control board, ESD discipline protects the very ASIC and microcontroller silicon you are trying to repair. The cost of a wrist strap is trivial against the cost of a latent failure.