Reliability in Selective Thinning Technology of Solder Resist for New IC Substrate Architecture

This paper presents a reliability aspect of the solder resist (SR) thinning technology. The resist thinning (RT) process was developed for thinning down SR layer highly uniformly at a large panel scale. By combined with photolithography process, the RT process can thin down SR materials selectively and can form multi-step structures. This paper first describes what the RT process is and what kind of benefit can be brought by applying the process. Then comparative studies in the impact of the RT process on SR material performances, such as surface morphology and material reliability, are reported. From the reliability study, it was revealed that the insulation reliability of SR materials was not impacted by applying the RT process. This research indicates that RT process is a beneficial tool for new SR structuring, without compromising materials performances.