Deng Yun Chena and Michael Ostermana
a CALCE, Center for Advanced Life Cycle Engineering, Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20740, USA
Abstract:
Conformal coatings have been used to protect the
electronic assemblies from corrosive gases, dust, and moisture. In
recent years, conformal coatings have been relied on to mitigate
the electrical shorting risk presented by tin mitigation, a hair like
conductive filament that grows from tin rich alloys. However,
there has been limited reporting on the effects of conformal
coating on the thermomechanical reliability of solder joints. This
paper presents details of an experimental investigation into the
effect conformal coatings on the reliability of solder joints under
temperature cycling, harmonic vibration, and drop tests. Acrylic
and thin parylene like coatings were used. The results show that
both conformal coatings can improve the reliability of solder
joints under temperature cycling, the coatings have very little
impact on the solder joint reliability under mechanical loadings.
Keywords: Conformal coating, Temperature cycling, vibration, drop test, Solder joint, Weibull, ALT, Testing