Title :
Formation of fine pitch solder bumps on polytetrafluoroethylene printed circuit board using dry film photoresist
Author :
Lee, Jung-Sub ; Chu, Kun-Mo ; Park, Hyo-Hoon ; Jeon, Duk Young
Author_Institution :
Dept. of Mater. Sci. & Eng., Korea Adv. Inst. of Sci. & Technol., Daejeon, South Korea
Abstract :
We demonstrated the applicability of dry film photoresists (DFR) in photolithography process for fine pitch bumping on the polytetrafluoroethylene (PTFE/Teflon®) printed circuit board (PCB). The copper lines were formed with 100μm width and 18μm thickness on the PTFE test board, and varying the gaps between two copper lines in a range of 100-200μm. The DFRs of 15μm thickness were laminated by hot roll laminator, by varying laminating temperature from 100°C to 150°C and laminating speed. We 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°C and speed of about 0.63cm/s. And the smallest size of indium solder bump was diameter of 50μm with pitch of 100μm.
Keywords :
chip-on-board packaging; copper; fine-pitch technology; flip-chip devices; indium; photoresists; printed circuit manufacture; soldering; ultraviolet lithography; 100 to 150 C; Cu; In; UV exposure; copper lines; dry film photoresists; fine pitch solder bumps; flip chip on board; flip chip technology; hot roll laminator; indium solder bumps; optimum process; photolithography process; polytetrafluoroethylene printed circuit board; varying laminating temperature; Copper; Dielectric constant; Dielectric losses; Dielectric materials; Dielectric substrates; Flip chip; Lamination; Optical films; Printed circuits; Resists;
Conference_Titel :
Asian Green Electronics, 2004. AGEC. Proceedings of 2004 International IEEE Conference on the
Print_ISBN :
0-7803-8203-X
DOI :
10.1109/AGEC.2004.1290883
