TABLE OF CONTENTS Although lasers have been evaluated for use in the circuit board industry for many years, only since 1995 has laser drilling been used in mass production. As of early 1999, the total number of systems in use was estimated to be in excess of 400 units. The rate of installations is more than 50 percent greater than the previous 12-mo period, a clear indication of the rapid adoption of this technology in the organic substrate fabrication industry. This increase in the popularity of the laser as a via formation tool is due partly to the flexibility of the process and partly to the wide range of circuit board materials that are laser compatible. This provides fabricators with the lowest entry cost to high-density interconnect (HDI) available today. The rapid productivity advances provided by system manufacturers have ensured that laser technology is moving into high volume production, with more microvias formed today by laser than by any other method.1
While mechanical drilling is dominant for through-holes with large diameters, laser via formation is more favorable for blind vias and microvias. At the end of 1999, laser via formation was still limited to only a few products. Worldwide, there were 400 laser systems in production, with 300 of those systems installed in Japan. Between 2000 and 2002, this situation is expected to change dramatically. Estimates predict that 350 million phones will be needed for the cellular market in the course of these 3 years. Production of these 350 million cellular...
