Fabrication of Blind Via Holes in Polyphenylene Ether films by Femtosecond Laser
Ya-Hsin Tseng1*, Chuan-Yu Yen1, Chih-Wei Luo1, Chih Wang2, Chi-haw Chiang2, Wen Chang Chen3, Chih-Jung Lin3, Min-Chi Yang3
1Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan
2Department of Chemistry, National Chung-Shan Institute of Science & Technology, Taoyuan, Taiwan
3Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan
* presenting author:ya-hsin Tseng, email:yahsin13@gmail.com
In this study, the ultrafast laser pulses with pulse duration of several tens femtosecond (fs, 10-¹⁵ s) were applied to fabricate blind via holes (BVH) in polyphenylene ether (PPE) films, with low dielectric constant and low dissipation factor, which can provide precisely matching patterns with extremely low thermal effect. The micron-scale BVHs with different diameters, ratios of major axis/minor axis and morphology were fabricated in the PPE films coated on the Cu/Teflon/Cu substrates by fs laser drilling with different polarizations, laser power, number of shots per micrometer, and objective lenses (NA value). Additionally, the processing condition-dependent BVH fabrication in PPE films without damages for Cu layer has been achieved in this study.

Keywords: polyphenylene ether (PPE), femtosecond laser, blind via hole (BVH)