More and more green legislations were adopted in the global community. These legislations have notably affected the electronic industry supply chain. Printed circuit board (PCB) as a critical part in electronic products or systems receives some of most severe impacts. The legalization of RoHS leads to lead-free soldermaterial development in the past 10 years. However, the lead-free alloys require higher reflow temperatures, which translate to higher energy costs as well as environmental loading in terms of carbon footprints. The high solder reflow temperature also forces changes in PCB base material and may require new equipment to fabricate them. The legalization of WEEE requires electronic waste to be recycled. PCB is used to be one of the most difficult parts to be recycled. WEEE also stipulates separation of components containing brominated flame retardants from other electronic waste prior to disposal or recycling. PCB fabrication companies have to stop using brominated flame retardants within the PCB base materials and prepregs and to develop substitutes. Further, to facilitate recycling, some toxic substances have to be avoided in PCB processes, for example, cyanide in gold plating and formaldehyde in electroless copper plating. These all demand changes and result challenges in PCB manufacturing. Global shortage of fuel and energy sources call for environmental friendly production processes, with less energy used and more precious metal recovered within the production cycle. Subsequently, alternative processes are to be developed to promote greenness in PCB fabrication.
ASJC Scopus subject areas