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Method for treating photolithographic developer and stripper waste streams containing resist or solder mask and gamma butyrolactone or benzyl alcohol

Technology:

A method is disclosed for using the simple environmentally-friendly organic compounds gamma-butyrolactone and benzyl alcohol to develop and to strip free radical-initiated addition polymerizable resists cationically cured resists and solder masks and Vacrel photoresists. In all cases the developers and strippers include gamma butyrolactone or benzyl alcohol. The developers and strippers optionally also include a minor amount of methanol ethanol isopropyl alcohol propylene glycol monomethylacetate ethylene glycol monomethyl ether formamide nitromethane propylene oxide or methyl ethyl ketone acetone and water. During development of the photopatterned resist or solder mask the unpolymerized regions are dissolved in the disclosed developers. During stripping of the resist or solder mask the polymerized regions are debonded from a circuit board in the disclosed strippers. Following removal of the developers and strippers any residual monomers or polymers of the resist or solder mask as well as residual developing solution and stripping solution are rinsed from the printed circuit package. A method is also disclosed for treating the combined developer and stripper rinse effluents in an activated biomass to reduce the biological oxygen demand of the developer/stripper/resist/solder mask waste streams.

Date of release: