PURPOSE: To execute pattern working to a copper sheet bonded ceramic substrate with high precision by using an etching soln. contg. specified amounts of one or more kinds among sulfuric acid, nitric acid and perchloric acid and iron(III)nitrate.
CONSTITUTION: A copper sheet bonded ceramic substrate is subjected to etching by using a etching soln. contg., per l aq. soln., total 0.2 to 4mol of one or more kinds among sulfuric acid, nitric acid and perchloric acid and 0.5 to 5mol iron(III)nitrate. Or, as the primary stage, etching by using an etching soln. contg., as main processing components, any of iron(III)chloride, copper(II)chloride, sulfuric acid + hydrogen peroxide and the acid complex of ammonium cuprate (II) is executed, and after that, as the secondary stage, the above etching is executed. As post treatment, it is immersed in a treating soln. contg., by pts.wt., 3 to 40 sodium hydroxide and 1 to 30 sodium chlorite in 100 water at ≥50°C to remove a Ti-N layer present between the brazing filler metal and the substrate layer.
KUMAGAI MASATO
FUNABASHI TOSHIHIKO
