Study and Application on Hexaarylbiimidazole Compound Photoinitiator for Photoresist of PCB

Compound photoinitiator systems were composed by photoinitiator bis[2-(o- chlorophenyl)-4,5-diphenylimidazole](BCIM)and photosensitizer N,N-bis(diethylami- no)benzophenone(EMK)with four different kind of hydrogen donors N-phenylglycine (NPG),2-mereaptobenzothiazole(MBO),2-mereaptobenzimidazole(MBI)and dodecanethiol (RSH).The phototsensitive properties of photoresist with the dierrent hydrogen donors and photoinitiator dosage were studied by real time IR.These photoinitiator systems were applied in liquid photoresist of PCB.The results suggested that the BCIM/EMK/NPG system is the most efficient and can substitute for photoinitiator 907/ITX system which common used in photoresist of PCB.