The purpose of this paper is to consider PTH solder joint reliability, particularly on the PTH solder joints with partial hole‐fill and without pin protrusion. Also, the impact of voiding on the solder joint reliability is discussed.
Thermal cycling tests for samples of different hole‐fill percentages and voiding were conducted, and cross‐sections of the PTH solder joints were performed to evaluate the solder microstructure, intermetallic formation, via hole‐fill, and the condition of the PTH metallization and PCB dielectric prior to thermal cycling and at different times during thermal cycling.
Different failure mechanisms were observed for solder joints with and without pin protrusion. PTH components with pin protrusion had better through hole‐fill and less voids than PTH components without pin protrusion.
The paper discusses in detail the effect of hole‐fill percentage and voiding on PTH solder joint reliability.
