Mark S. Oliver

Low Residual Stress and High Performance Dielectric for WLP (Wafer Level Packaging) Applications

The advanced packaging application space continues to evolve as mobile devices pack more and more features into a limited space. This feature concentration is causing a deviation from the conventional shrinkage pathway predicted by Moores law which, in turn, requires dielectric materials with ever more rigid thermal, chemical, and mechanical properties to meet the challenging requirements of next generation packages such as TSV and 3D chip stacking. One such challenge is the thinner substrates required for vertical integration in TSV and 3D packages. Cured dielectrics impart stress onto the underlying substrate and this wafer bow will only magnify with thinner substrates. Designing photodielectrics with inherently lower residual stress will greatly aide in the development of materials to meet future advanced packaging needs. This presentation will outline the development of a new photodielectric material that builds upon the excellent thermal, electrical, and chemical stability of BCB-based materials whi...

Temporary and Permanent Adhesives for Thin Wafer Handling and Assembly

Temporary wafer bonding has emerged as the method of choice for handling silicon wafers during the thinning and high-temperature backside processing required for the manufacture of 3D device structures. Among the requirements for temporary wafer bonding materials to be used in high volume manufacturing are simple device and carrier wafer preparation, high-throughput wafer bonding, excellent thermal stability, and clean room-temperature release directly from the device wafer. We will present successful temporary wafer bonding using a new BCB (benzocyclobutene)-based material that can meet these requirements. For this temporary wafer bonding technology, wafer preparation involves spin coating the device wafer with the BCB-based adhesive to a thickness of up to 100 μm and spin coating the carrier wafer with an adhesion promoter. The wafers can then be bonded at temperatures as low as 80 °C for as short as 30 seconds. The low bonding temperature means the wafers can be loaded into a preheated wafer bonding to...