Kazuhito Hikasa, Toshiaki Amano, Toshiya Hikami, Ken'ichi Sugahara and Naoyuki Toyoda
Recently electronic equipment have remarkably been improved becoming lighter and more compact and having upgraded functions, requiring electronic components mounted thereon to have more pins, smaller pitches, and smaller mounting spaces. Thus chip size package (CSP) has become the mainstream of packages for chip-sized electronic components. In response to such situations, the authors have developed a flexible bumped tape interposer (FBTI) with solder bumps for flip-chip processing of CSPs. The vias of this interposer are filled with metals such as Cu or solder, and chips are mounted by flip-chip bonding the SnAg-solder bumps with the Au stud bumps on Si chips. Consequently, this interposer can cope with such requirements as higher frequencies, elimination of Pb, and higher bonding reliability. This paper reports on the structure, manufacturing process, features, results of prototype manufacturing, reliability, and application examples of this interposer.