Target and uniformity controls of WLP in SSL/LED manufacturing

Advanced process controls (APC) have been ubiquitously applied to the manufacturing processes of semiconductor devices for over two decades by now. Reports on its successful applications to the makings of light-emitting diodes (LED) in the solid-state lighting (SSL) industry however are comparatively less well documented in the literature [1-4]. The concluding remark in [1], ‘…APC is not yet reality … on the right track ….’ precisely summarizes the current state and difficulties of actual practices in reality.