Detection of CDM Failure

General Discussion
#1

Dear Sir,

Right now we don’t have any tool to detect or correctly evaluate CDM. In other point of view, we can’t also “prove” that there is no CDM failures.

ANSI/ESD S20.20-2021 say that lower limit of 10^6 ohm should be considered if there is a concern of CDM.

Could you please suggest and advice here? Thanks a lot in advance.

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#2

Hi Sarban,

Out of curiosity what are you checking under CDM and how are you stressing it?

Regards
Cao

#3

CDM events are considered metal to metal contacts. That is why the discharge is very fast and can generate a large current. Using a mat that is greater than 1x10*6 will dissipate some of the energy in the mat and reduce the current that can be generated.

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#4

Hello Johnk,

Thanks for your response. Need your help to provide more details on CDM testing. How we can measure CDM test? What equipment’s need to be used for CDM testing? Also what type of items comes under CDM testing ?

Appreciate your response as always. Thanks

#5

CDM testing is only for devices to charaterize them. There is no CDM test for ESD control materials. To evaulate the ESD control process, I suggest you look at ANSI/ESD SP 17.1 - Process Assessment. This document will provide methods to evaulate risks of the ESD controls used in your process. It gives you a list of possible methods to perform to help evaluate the limits of your process.

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#6

Thanks a lot Johnk for your guidance.

I will go through ESD SP17.1 for further clarity and understand the requirement.