The Charged Device Model (CDM)

This model was born in 1974 with the proposal by Speakman that a part such as an integrated circuit might be damaged or destroyed by rapid discharge of static electricity accumulated on the part’s own body (Ref. 5-1). In 1980, the CDM was judged the predominant failure mode at AT&T, as typified by dual-in-line packages (DIPs) sliding within their plastic packaging tubes to become triboelectrically charged with most of the charge residing on the lead frame (Ref. 5-2). In 1992, it was said, “It has become clear in the past five years that the CDM, not the HBM, is responsible for the vast majority of ESD damage, certainly to discrete devices and probably to entire circuit cards and assemblies” (Ref. 5-3). Reflecting industry concern about the CDM, certain packaging materials are now being advertised as “CDM-safe.”