TY - GEN
T1 - Factors that influence ionic migration on printed wiring boards
AU - Reid, M.
AU - Punch, J.
AU - Rodgers, B.
AU - Pomeroy, M. J.
AU - Galkin, T.
AU - Stenberg, T.
AU - Rusanen, O.
AU - Elonen, E.
AU - Vilèn, M.
AU - Väkeväinen, K.
PY - 2005
Y1 - 2005
N2 - Ionic migration on printed wiring boards (PWBs) involves the transport of metal ions between two copper tracks under bias through an aqueous electrolyte, which results in deposition at the cathode. Dendrite-like deposits are then formed, leading to a short circuit and subsequent failure. Standardised test 85°C/85%RH (relative humidity) is typically used for modelling and predicting ionic migration failure, however, the possibility of moisture condensation - a prerequisite for ionic migration - at such a relatively high temperature and low relative humidity is unlikely. In order to assess the effects of moisture condensation, this work compares two extreme tests for ionic migration on PWBs. The two tests are water droplet (WD) and cyclic temperature - relative humidity (20°C to 35°C, 95%RH maximum, with 21 hr cycle) conditions under a bias of 5V DC. The cyclic test was conducted over a 21 day period with continuous in-situ monitoring of dendritic growth. Water drop tests were performed in order to draw correlation with cyclic tests. Investigative techniques were conducted to evaluate the migration development on the PWBs after testing using optical microscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDS).
AB - Ionic migration on printed wiring boards (PWBs) involves the transport of metal ions between two copper tracks under bias through an aqueous electrolyte, which results in deposition at the cathode. Dendrite-like deposits are then formed, leading to a short circuit and subsequent failure. Standardised test 85°C/85%RH (relative humidity) is typically used for modelling and predicting ionic migration failure, however, the possibility of moisture condensation - a prerequisite for ionic migration - at such a relatively high temperature and low relative humidity is unlikely. In order to assess the effects of moisture condensation, this work compares two extreme tests for ionic migration on PWBs. The two tests are water droplet (WD) and cyclic temperature - relative humidity (20°C to 35°C, 95%RH maximum, with 21 hr cycle) conditions under a bias of 5V DC. The cyclic test was conducted over a 21 day period with continuous in-situ monitoring of dendritic growth. Water drop tests were performed in order to draw correlation with cyclic tests. Investigative techniques were conducted to evaluate the migration development on the PWBs after testing using optical microscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDS).
UR - http://www.scopus.com/inward/record.url?scp=28744434481&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:28744434481
SN - 0780388038
T3 - IEEE International Reliability Physics Symposium Proceedings
SP - 300
EP - 304
BT - 2005 IEEE International Reliability Physics Symposium Proceedings, 43rd Annual
T2 - 2005 IEEE International Reliability Physics Symposium Proceedings, 43rd Annual
Y2 - 17 April 2005 through 21 April 2005
ER -