Glenn Simenson

Microvia formation with lasers

Laser drilling has emerged in the last five years as the most widely accepted method of creating microvias in high-density electronic interconnect and chip packaging devices. Most commercially available laser drilling tools are currently based on one of two laser types: far-IR CO2 lasers and UV solid-state lasers at 355 nm. While CO2 lasers are recognized for their high average power and drilling throughput, UV lasers are known for high precision material removal and their ability to drill the smallest vias, with diameters down to about 25 -30 micron now achievable in production. This paper presents an overview of techniques for drilling microvias with the lasers.

High-speed microvia formation with UV solid state lasers

Laser drilling has emerged in the last five years as the most widely accepted method of creating microvias in high- density electronic inter connect and chip packaging devices. Most commercially available laser drilling tools are currently based on one of two laser types: far-IR CO2 lasers and UV solid state lasers at 355 nm. While CO2 lasers are recognized for their high average power and drilling throughput, UV lasers are known for high precision material removal and their ability to drill the smallest vias, with diameters down to about 25-30 micrometers now achievable in production. This paper presents a historical overview of techniques for drilling microvias with UV solid state lasers. Blind and through via formation by percussion drilling, trepanning, spiralling, and image projection with a shaped beam are discussed. Advantages and range of applicability of each technique are summarized. Drivers of throughput scaling over the last five years are outlined and representative current-generation performance is presented.