ESD sensitive (ESDS) device sensitivity level

The most important thing that an ESD Coordinator must know before setting up an ESD Control program for his organization is the ESD sensitivity level for the most sensitive component or part used in the product manufactured by the organization.

By knowing the ESD sensitivity level of the most sensitive ESDS component, it helps the ESD coordinator to establish the ESD controls required for his ESD Control program.

Basically an ESDS electronic device can be damaged by three common mechanisms:

• Discharge from a charged human body into the ESDS device a.k.a Human Body Model (HBM) damage mechanism
• Discharge from a charged conductive part of a machine into the ESDS device a.k.a Machine Model (MM) damage mechanism
• Discharge from a charged ESDS device to a grounded conductive surface a.k.a Charged Device Model (CDM) damage mechanism

The ESD sensitivity level of the ESDS electronic device is commonly documented in the
Material or Component Data sheet or Component Reliability Data sheet.
Some ESDS electronic component manufacturer would tabulate out all the three, i.e. HBM, MM and CDM ESD withstand voltage level and some would only tabulate out only the common HBM and MM ESD withstand voltage level of the device.
ESD withstand voltage is the maximum ESD level that the ESDS can withstand without being damaged.
Anything above the ESD withstand voltage level, the ESDS device or component would either be malfunctioned or damaged permanently.

There is a variety of testers available in the marketplace where semiconductor electronic device manufacturers could test their devices in accordance to the ANSI/ESD standards.

• HBM ESD testing : ANSI/ESD STM 5.1
• MM ESD testing : ANSI/ESD STM 5.2
• CDM ESD testing : ANSI/ESD STM 5.3.1

Knowing the ESD sensitivity levels of the most sensitive ESDS device being handled in the organization would not only help the ESD coordinator to set up appropriate ESD Controls but also would help the ESD coordinator to set up an ESD Control program which is cost effective for his organization.

Under certain circumstances where the ESD sensitivity level for the most sensitive ESDS component is unknown which occurs most of the time, the ESD coordinator can set up his ESD Control program based on ANSI/ESD S20.20 standard requirement. ANSI/ESD S20.20 standard specify controls which provide protection for ESDS component from damage by Human Body voltage greater than or equal to 100V.

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