Laser Etching
Laser etching has been shown to be a viable technique for via formation in CYCLOTENE* resins. Both eximer and CO2 lasers have been used.
Etching Rate of Photo-CYCLOTENE vs Laser Fluence

CO2 Laser Etched Via in CYCLOTENE Resin Coated Foil Build Up Board

®™* Trademark of The Dow Chemical Company ("Dow") or an affiliated company of Dow