Patent ID: 7189336
Filing Date: 2007-03-13
Classification: C23F,H05K

Abstract:
1. A method for roughening a copper surface comprising subjecting the copper surface to etching using an etchant so that the copper surface is provided with acicular protrusions, said etchant including a main component containing at least one first compound selected from the group consisting of oxo acids represented by one of the following formulae: wherein X is a central atom, m is an integer of 0 or more and n is an integer of 1 or more and derivatives thereof and at least one second compound selected from the group consisting of peroxides and derivatives thereof; and an auxiliary component containing at least one azole and at least one halide, the at least one azole comprising benzotriazole and the concentration of the benzotriazole in the etchant is 1 to 10 g/l, the at least one halide comprises chloride, the chlorine concentration of the chloride in the etchant is 0.006 to 0.182 g/l, and the chloride is one selected from the group consisting of sodium chloride, potassium chloride and stannous chloride, wherein said acircular protrusions formed from etching said copper surface have a height of about 2 to 5 μm, wherein the roughened copper surface is adapted to be joined to an outer layer material.