DART Contact Resonance Images of Cu-alloy/PC Board Junction

The topography and simultaneously measured contact resonance frequency and quality factor of the junction between Cu-alloy and polymer PC-board layers. The layer was measured in the vicinity of a ball-grid array (BGA) solder joint as part of a mechanical failure analysis test. The different mechanical properties of the Cu alloy and the PCB resulted in a >100 kHz contact resonance frequency shift between the two regions, as well as significantly higher dissipation in the PCB material. 12 µm scan. Imaged with the MFP-3D AFM. Sample courtesy of Dr. Hahn, Korea Research Institute of Standards and Science, South Korea.