CHEMICAL ETCHING OF POLYIMIDE FILM

Chemical etching rates of BPDA/PDA/ODA/BMI polyimide film by an alkali ne etching solution with the presence of different kinds of etchants w ere studied by film-thickness measurement and UV absorption spectrosco py of dispersible etching residue. The etching rate of polyimide film in alkaline ethylene diamine solution is highest among the etching sol utions studied in the present experiment. If an external bias voltage was applied during etching, the etching rate was increased. The effect s of temperature, solubility of the etchant, and ultrasonic vibration on etching rate are also discussed. The presence of a radical in the p rocess of etching reveals that the etching reaction is a type of radic al chain reaction. (C) 1995 John Wiley & Sons, Inc.