charged device model

Setting CDM test goals has long lacked clear guidance on what counts as adequate performance. New analysis grounded in radial transmission line theory calculates fundamental limits on peak current and slew rate for devices of any size, offering engineers a way to evaluate risk against real use conditions.

A new discharge current sensor installed directly inside an assembly machine captures real ESD events during pick and place operations for the first time. Award winning research reveals how tool speed and moving path change discharge current, giving MCM and SiP designers data to target protection precisely.

A common ESD flooring assumption gets the physics backwards — and it could be steering facilities toward the wrong resistance category entirely. Drawing on decades-old Bell Labs research, this piece traces exactly where a CDM event actually begins, and why flooring resistance alone won't protect against it.

Secondary discharges during Field-Induced CDM testing aren't just measurement anomalies—they're real stress events caused by mechanical bouncing of the pogo pin. This groundbreaking investigation reveals how contact vibrations trigger unintended zaps with opposite polarity, provides electrical proof of the mechanism, and offers practical solutions to prevent this hidden reliability threat.

Real-world ESD discharge currents during semiconductor assembly differ dramatically from standard test predictions. A new Discharge Current Sensor reveals that actual currents are lower but faster than expected, challenging current protection designs for Multi-Chip Modules and Systems in Package.

A Charged Device Model (CDM) simulation method has been demonstrated to predict CDM fail current of receiving circuits with gate oxide connected to pad. This method involves inclusion of 20ps rise time edge into the stimulus. It was shown previously that this fast rise time component of the pulse can cause the gate oxide damage. The simulation method is intended as a schematic-level tool during pre-silicon design phase to deliver CDM ESD protection. Simulation results are verified by silicon results with qualification CDM test on package and Transmission-Line-Pulse (TLP) measurements on wafer-level.

It is now well known that testing for CDM ESD evaluation is becoming a bigger challenge. An alternate approach called capacitively coupled transmission line pulsing (CCTLP) offers advantages over standard field-induced CDM testing.

This blog explains CDM ESD testing using the field-induced (FI) method, which is important for semiconductor manufacturers. It covers building a CDM-FI tester, waveform details and verification, and qualification nuances. 

The behavior of ultra-high-speed interfaces is complex, involving fast-rise time waveforms and on-die transient phenomena that cause device failure at lower CDM levels.

Most ESD experts consider CDM testing to be the most critical ESD qualification test for modern integrated circuits. ESD control engineers need to know the charged device ESD robustness of all components passing through their manufacturing line. CDM measurements provide that knowledge.