Dr. Katsuyuki Sakuma
Research Staff Member, IBM T.J. Watson Research Center
3D IC integration technology and large die packaging are essential ingredients for further performance enhancement of main frame and super-computer applications, but warpage of large and thin interposers is one of the biggest challenges in achieving large die 3D IC integration. In addition to that, a micro-bump pitch for 3D application is becoming smaller in order to achieve higher bandwidth I/Os, hence removal of flux residue becomes more difficult. To eliminate the use of flux and its associated cleaning process during flip chip bonding, a micro-scrub thermo-compression (TC) bonding process was evaluated as a potential bonding method. We also demonstrated a successful bonding process for large die 3D IC integration with 22 nm ULK CMOS technology by developing an enhanced TC bonding process that addresses problems caused by interposer and laminate warpage. Both TC bonding technologies will be discussed.