Preparation and Property Evaluations of Liquid Non-Solvent Solder Resists which Can be Developed with Alkaline Solution

Shoji Inagaki, Toshiyuki Oyama
2016 Journal of The Japan Institute of Electronics Packaging  
Solder resist materials which do not contain solvent as a component and can be applied to off-contact exposure method were studied for their application to alkaline-developable solder resists of printed circuit boards. We found a photopolymerization initiator system composed of photoradical initiator, amine and thiaxanthone which showed good curability both on the surface and in the interior under aerial condition. We also succeeded in preparation of alkaline-developable photosensitive resin by
more » ... osensitive resin by two-step reactions starting from novolac-type epoxy resin. Effect of solid and liquid epoxy resin components added for thermal post-curing on properties as solder resist was also examined. As a result, regardless of the epoxy component, the solder resists having good adherence, high solder heat resistance of 260°C for 30 s and resolution of 100 μm or higher were successfully obtained. These results demonstrate that a solder resist which is developable with alkaline solution and applicable to printed circuit boards for general uses can be produced from liquid photosensitive resins without solvent component.
doi:10.5104/jiep.19.189 fatcat:rcioh6uzybhklatemiukgsg6uu