The measurement of residual deformation in PBGA package after reflow process using a newly developed laser profiler

Abstract

For measuring deformation of electronic packages, various techniques have been used. Each technique has some merits and demerits. Some techniques have very high resolution but small measuring area. On the contrary, other techniques have large measuring area and low resolution. So the judicious selection of techniques with a trade-off between the resolution and available measuring area is important. In this research, a new laser profiler was developed by integrating high resolution laser displacement sensor into the x-y scanner. This system has 10nm vertical resolution and 100nm horizontal resolution with a measurement area up to 25mm by 25mm. The residual deformation of a lead-contained and lead-free PBGA package after reflow process was measured by the newly developed system. And the effect of aging was evaluated.