Using Faraday cup + Coulomb meter - Precautions?

#1

Hi all ESD Expert,

I am wondering that is there anything should be noticed when using (Faraday cup + Coulomb meter) to measure static charge ?

Question :

  1. In order to measure static charge accurately, the capacitance of Faraday cup + Coulomb meter should be much lower than device under test(DUT), e.g., IC, right ?
  2. If it’s right, how can I guarantee DUT capacitance?
  3. Or I just no need to worry this issue, just measure it?
  4. Other thing - any document I can refer to?

Kindly advise, thank you.

Bruce

#2

Hi Bruce,

A Faraday cup just measures charge. It does not take into account capacitance of any device.
When a part or device is placed into a faraday cup there are two types of charge, mobile and non-mobile charges. The cup does not know the difference.
Be careful that the device does not tough the sides of the cup when placed in. The only documentation that I know of would come from the manufacturer of the cup itself.

#3

Hi John,

Noted, thank you!

Bruce