Oue of the major alignment challenges faced by assembly engineers today is the accurate assembly of high-end optoelectronic modules. Silicon optical platform applications, where a laser diode is aligned to a single mode fiber or an optical waveguide, require post-bonding alignments better than 1 micron for optimum device performance.
25 um thick dies, mounted on thick carrier die, were placed on a 300mm landing wafer using the High Accuracy Die Bonder SET-FC300. The bonding process was either Cu/Cu or Cu/Sn with respective pitch of 10μm and 40μm. A special test structure was designed on the landing die to electrically determine the alignment accuracy after bonding - both with respect to the X-Y alignment and the rotation. Stacks were then assembled by collective hybrid bonding process. The top die is aligned and placed on the landing wafer coverer by a patterned polymer acting as a temporary alignment holder, and then the populated wafer is moved to a wafer bonder where all the dies are collectively bonded. Electrical measurements on the alignment structures indicate that maximum misalignment of the TSV to the landing pad is in the range of 1.5–1.75 um and the maximum rotation of the die is 0.03 degrees.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.