Process for forming wiring on substrate

摘要

In a process for forming a wiring conductor of Cu, Al, Au or the like on a wiring substrate, polyimide-based resin having the following unit structural formula is used as a lift-off material. <IMAGE> wherein R1: <IMAGE> R2: <IMAGE> n is an integer of 15,000 to 30,000. This lift-off material has very good etching susceptibility and can be selectively lifted off with an etching solution of a mixture of hydrazine and ethylene diamine from a lower polyimide layer having R1: <IMAGE> R2: <IMAGE> .