Die Sticking Quality Issue of Tape-and-Reel Packaging for WLCSP

Various factors could deteriorate the quality of Tape-and-Reel (TnR) packaging for Wafer-level Chip Scale Package (WLCSP) devices, of which “die sticking onto cover tape” issue found during die pick-up from the pocket or carrier tape during the Surface-mount Technology (SMT) process is a serious real-world challenge. If TnR packaging process is not carefully designed and monitored, such die sticking events would significantly slow down die pick-up throughput, and millions of units could be placed on hold by end customer, with serious financial ramifications. A series of design of experiments (DOEs) were carried out, as a collaboration between ADI and UTAC, to explore this die sticking phenomenon. Based on lessons learned from production runs of WLCSP devices, along with the results of the DOEs as presented in this paper, new and improved Tape-and-Reel packaging design guidelines were formulated for preventing the occurrence of die sticking issue.