White Paper 2: A Case for Lowering Component Level CDM ESD Specifications and Requirements
- Last Updated on Monday, October 08, 2012 18:44
CDM has become the primary real world ESD event metric describing ESD charging and
rapid discharge events in automated handling, manufacturing and assembly of IC devices.
Its importance has dramatically increased in the last few years as package feature sizes,
capacitance and pin count have scaled upward. In recent years, arbitrary CDM protection
levels have been specified as IC qualification goals with little background information
available on actual/realistic CDM event levels and the protection methods available in
controls and device design for safe production of IC components. The rapid advancement
of IC technology scaling, coupled with the increased demand for high speed circuit
performance, are making it increasingly difficult to guarantee the commonly customer
specified “500V” CDM specification. At the same time, the required static control
methods available for production area CDM protection at each process step have not been
fully outlined. Therefore, a realistic CDM specification target must be defined in terms of
available and commonly practiced CDM control methods, and also must reflect current
ESD design constraints. This is the scope of this White Paper II.
By balancing improved static control technology specific to CDM, and limited ESD
design capability in today’s leading technologies, we recommend a CDM specification
target level of 250V. This is considered to be a realistic and safe CDM level for
manufacturing and handling of today’s products using basic CDM control methods.
At the same time we show that the current trend of silicon technology scaling will
continue to place further restrictions on achievable CDM levels. It is therefore necessary
that we present a realistic CDM roadmap for consideration by the industry moving
forward to the next two levels of scaled technologies approaching 22nm and beyond.