Robert M. Japp

Introducing Biobased Materials into the Electronics Industry

Abstract: Lignin, a biopolymer formed in the cell walls of plants, is a by-product of paper manufacturing. In research at IBM, it was incorporated into a resin used in the fabrication of printed wiring boards (PWB) for the microelectronics industry. The resin had physical and electrical properties similar to those of current laminate resins. PWBs fabricated from the lignin-based resin passed most of the standard physical, electrical, and reliability tests for an “FR4”-grade laminate. A comparison of the lignin-based resin and current resins via life-cycle assessment indicated up to 40% lower energy consumption for the biobased resin. Large-scale manufacture of lignin-based resins would require an inexpensive source of lignin with low ionic contamination.

Low Dielectric Constant Laminates Containing Microspheres

As electronic devices become faster, the effective dielectric constant of the circuit packaging connecting them becomes more important. The dielectric constant of standard epoxy/glass laminates can be significantly reduced by the addition of hollow glass microspheres. However the addition of such microspheres usually results in the degradation of other physical, electrical and mechanical properties which are prerequisites for materials to be used in commercial circuit packaging. By carefully optimizing the formulation many of these undesirable effects can be avoided. These topics and others pertaining to the development and testing of a microsphere laminate are discussed.