Patent ID: 7244370
Filing Date: 2007-07-17
Classification: B41J,H05K

Abstract:
1. A method for producing a circuit substrate provided, on an insulating surface of a substrate, with a plurality of elements each including a resistive layer and electrodes constituted of a conductive material containing aluminum and positioned with a predetermined spacing on said resistive layer, the method comprising: (a) a step of laminating, on the insulating surface of the substrate, a resistive material layer for forming the resistive layer, and an electrode material layer constituted of a conductive material containing aluminum for forming the electrodes, in succession in this order; (b) a step of forming, on the electrode material layer, a resist layer (I) having a pattern for isolating said resistive material layer and said electrode material layer into each element; (c) a step of patterning the resistive material layer and the electrode material layer by dry etching based on the pattern of said resist layer (I) thereby forming a laminate structure in which the electrode material layer is laminated on the resistive material layer; (d) a step of eliminating the resist layer (I) on said laminate structure; (e) a step of forming a resist layer (II) having a pattern for forming the spacing; and (f) a step of patterning the electrode material layer by wet etching with an etching solution containing an acid or an organic alkali having an etching ability and a chelating agent capable of forming a complex with the conductive material, based on the pattern of said resist layer (II), thereby forming the spacing to complete the element.