Abstract
In high-purity gold-plating baths for electronic components, a trace amount of thallium is added as a grain refiner. At high current densities, however the thallium content of the gold deposits increases and wire bondability deteriorates. In this study, pulse plating was investigated as a method of decreasing thallium content. It was found that there was little thallium in deposits obtained using pulsed waves of 125Hz frequency and a 75% duty cycle. Micrographs and X-ray diffraction patterns showed that the crystals were large and grew in a relatively random under pulse plating.
