Nd-YAG laser microvia drilling for interconnection application

Interconnect via formation using a diode-pumped solid-state Nd-YAG laser is becoming an important technique for the high volume manufacturing of microelectronics. However, ablative microvia formation using Nd-YAG lasers suffers from poor quality at sidewalls and top surface, which affects the subsequent metallization process. In this paper we examined various parameters to improve the drilling quality. The influence of wavelength (355 nm and 532 nm) on the machining quality was also studied in detail. A comparative analysis between single-shot and multiple-shot ablation was tested and discussed at a wavelength of 532 nm.