Challenges and Solutions in Fine Line AOI

摘要

High Density Interconnect (HDI) substrates incorporate fine line PCB technology- boards with narrower lines and spaces, thinner cores and higher aspect ratios. As technology is pushed to its limits, there is usually a reduction in yield. The role of inspection becomes ever more vital in overcoming yield losses. The characteristics of fine line panels raise specific challenges that make detecting defects harder. Among the issues that characterize fine line manufacturing we find: 1. Maintaining line integrity as line width drops below 50μm (2 mil). This issue becomes more severe as line width approaches 15μm (0.6 mil) 2. Obtaining the smooth surface finish mandatory for good adhesion between the copper and the laminate 3. Meeting the tighter tolerances required to control impedance 4. Embedding passive components