Laser processing - the future of HDI manufacturing

Conventional electronics manufacturing technologies have become unsuitable for high density interconnect structures (HDIS) due to processing limitations, lower manufacturing yields, higher production costs and limited flexibility. Laser processing is one suitable solution for manufacturing HDIS. This is supported by published reports that over 90% of all microvias in HDI PWBs and chip package substrates are formed using laser technology (D.F. Downey et al, 1993). Lasers are ideal primarily due to their high-resolution processing capabilities, fast processing speeds, reliability, versatility and lower cost-of-ownership. Focusing on these factors, this paper highlights key developments in laser processing which are relevant for advancing HDI technology. Particular emphasis is placed on new developments in CO₂, UV and diode-pumped solid-state laser processing for improved HDI fabrication. Laser performance characteristics, including optimal selection of key process parameters for improved HDI fabrication, and cost-of-ownership models are presented for each laser technology. After discussing the benefits of using existing laser technologies for HDI manufacturing, this paper provides an insight into emerging laser technologies, which are currently under development and driven by the electronics industry. A preview of these technologies and the potential capabilities for the electronics manufacturing industry are presented.