Kinder computer circuit boards on IBM horizonBy Lynn Davis
Spectrum Volume 19 Issue 18 - January 30, 1997
In the near future, the printed circuit boards (PCB's) on which computer chips are mounted will be kinder to the environment. Researchers from Virginia Tech's Department of Wood Science and Forest Products and the Department of Chemistry are working with IBM to design a PCB and other computer products that will minimize environmental impact because the materials will be engineered to be disassembled, reused, and/or recycled.
Researchers include Wolfgang Glasser, associate dean of research and professor of wood chemistry in the College of Forestry and Wildlife Resources; Jim McGrath, director of the Center on High Performance Polymeric Adhesives and Composites; and Thomas Ward, endowed chemistry professor; and their staffs. They have developed a printed-circuit board called a "Green Card" that will contain no solvents, reduce energy requirements, and use such new resin systems as resins derived from natural renewable resources.
When IBM began looking for more environmentally sensitive substitutes for the materials of which today's computers are made, they saw in the research literature that Virginia Tech scientists have been studying the chemistry and utilization of lignin in plastics for more than 20 years. Lignin is a complex polymer, which acts as a natural glue to tie cellulose fibers together in trees.
IBM asked the Virginia Tech researchers to develop a good substitute for the plastic board currently used in the computer industry. Chemists and wood scientists went to work and devised a microwave process to produce a resin. They developed water-based systems that replace the use of large amounts of organic solvent (methyl ethyl keytone, MEK) that have traditionally been used.
And they developed the end product-epoxy resins themselves. The resins are based on "biopolymers"-modern materials that are derived from plants, trees, and microorganisms. Unlike oil-based resources, these materials are renewable and easy to recycle.
Experiments with epoxy resins with 50-percent lignin are proving to provide a PCB with equivalent or better thermal and electrical performance than current high-volume PCB's.
There are other advantages to using the resin materials. Cost is significantly lower. PCB's made of lignin also will reduce dependence on fossil fuels and reduce waste streams in paper mills-lignin is produced in pulp mills in volumes similar in magnitude to the production of paper.
Thanks to an effective partnership among industry, academia, and government, the innovative green technologies will be implemented rapidly. Research was sponsored by ARPA (Advanced Research Project Agency), EPRI (Electric Power Research Institute), NYSERDA (New York State Energy Research Development Authority), and NYSEG (New York State Electric and Gas), along with IBM.