Formation of Fine Pitch Solder Bumps on Polytetrafluoroethylene Printed Circuit Board using Dry Film Photoresist

Dry Film Photoresist를 이용한 테프론 PCB 위 미세 피치 솔더 범프 형성

  • 이정섭 (한국과학기술원 신소재공학과) ;
  • 주건모 (한국과학기술원 신소재공학) ;
  • 전덕영 (한국과학기술원 신소재공학과)
  • Published : 2004.03.01

Abstract

We have demonstrated the applicability of dry film photoresist (DFR) in photolithography process for fine pitch solder bumping on the polytetrafluoroethylene (PTFE/Teflon ) printed circuit board (PCB). The copper lines were formed with 100$\mu\textrm{m}$ width and 18$\mu\textrm{m}$ thickness on the PTFE test board, and varying the gaps between two copper lines in a range of 100-200$\mu\textrm{m}$. The DFRs of 15$\mu\textrm{m}$ thickness were laminated by hot roll laminator, by varying laminating temperature from $100{\circ}C$ to 15$0^{\circ}C$ and laminating speed from 0.28-0.98cm/s. We have found the optimum process of DFR lamination on PTFE PCB and accomplished the formation of indium solder bumps. The optimum lamination condition was temperature of $150^{\circ}C$ and speed of about 0.63cm/s. And the smallest size of indium solder bump was diameter of 50$\mu\textrm{m}$ with pitch of 100$\mu\textrm{m}$.