Optimizing BGA to PCB interconnections using multi‐depth laser drilled blind vias‐in‐pad

Ball grid array (BGA) component packages challenge the circuit board design with signal routing and layout, creating in some cases extra board layers and added vias all resulting in increased costs for the printed circuit board (PCB). As component densities increase and microBGA ( μ BGA) and other fine pitch components become more common, microvia‐in‐pad technology will ease the transition to these fine pitch components. This paper presents and profiles a cost‐effective solution to interconnecting BGAs on PCBs using laser drilled blind vias connecting the outer three or more layers of a multilayer circuit board. Following a discussion on the design advantages, a comprehensive outline of the PCB fabrication process explores a new procedure for the rapid production of via‐in‐pad multi‐depth blind via laser drilling.