Dielectric Laser Via Drilling for Next Generation Wafer Level Processing

The common via formation processes used today for dielectrics in WLCSP RDL and flipchip products typically rely on standard photolithography processing using stepper and 1x aligner equipment and processes. There is considerable interest in using laser via drilling (ablation) in dielectrics for flipchip, RDL inner layer, and WLCSP processing for reduced via dimensions and enabling a broader range of dielectric materials, including inherently non-photosensitive options. This presentation will demonstrate “state of the art” laser ablation process results, through different dielectrics showing improved feature resolution and reduced via opening sizes resulting in significantly improved interconnect density. Laser via drilling is a more simplified process compared to traditional photolithography methods. This presentation will demonstrate how using laser via drilling could dramatically improve the design rules for next generation RDL designs.