Patent ID: 6783921
Filing Date: 2004-08-31
Classification: H05K,Y10T

Abstract:
A method for etching a laminated assembly including a polyimide layer, which comprises etching a laminated assembly comprising a metal layer and a non-thermoplastic polyimide layer bonded together via thermoplastic polyimide with an etchant at least containing an alkali metal hydroxide, water and oxyalkylamine,wherein the concentrations of the alkali metal hydroxide (X weight %) and of the water (Y weight %) have relationships represented by coordinate points present within a region (inclusive of boundary lines) defined by the following expressions [1] and [2]: Y=(Â½)X (provided that 7&lE;X&lE;45)â€ƒâ€ƒ[1]Y=({fraction (5/20)})X+17.5 (provided that 7&lE;X&lE;45)â€ƒâ€ƒ[2]provided that X and Y are defined based on the total weight of the alkali metal hydroxide, water and oxyalkylamine expressed as 100.