Processing and performance of high density interconnect (HDI) PWB with laser microvias

Abstract

Why do we need to supply microvias? New components, such as thin small outline packages (TSOPs), chip size packages (CSPs) and direct chip attachment (DCA) are forcing designers to create new layouts which challenge the fabricator to manufacture printed wiring boards (PWBs) with higher packaging densities, finer lines, smaller holes and blind vias to accommodate more functions on the interconnect structure. At the same time, continuous cost reduction is required by the OEM to meet the needs for lower-cost electronic equipment, forcing the PWB fabricator to improve manufacturing processes to meet the new cost and processing technologies and performance imperatives. This paper describes how the PWB fabricator can modernized the manufacturing processes to produce HDI PWBs using micro via-hole technology. It also shows how the key goals of retaining existing equipment, processes and people, combined with focused and dedicated investment strategy, were achieved. It also shares the practical experience obtained during the transition to HDI PWB manufacture and provides test data on the resulting manufacturing and product performance. The risks of venturing are minimized by a close relationships between PWB designers and fabricator.