ELECTROLESS COPPER PLATING METHOD, OXYGEN SUPPLYING DEVICE USED TO THIS METHOD AND ELECTROLESS COPPER PLATING APPARATUS USED TO THIS METHOD

摘要

PURPOSE:To stabilize plating solution and to prevent lowering of precipitating velocity of a copper by increasing soluble oxygen in the plating solution up to the specific value according to increase of sp. gr. of the electroless copper plating solution. CONSTITUTION:During using the electroless copper plating solution containing 10g/l copper surface as Cu ion source, 4.5ml/l formalin as reducing agent for Cu ion, 60g/l ethylenediamine-tetraacetic acid as complexing agent and material refining agent and non-cyanogen series stabilizer and having 12.4 pH, lowering of plating capacity of the plating solution is detected with increase of this sp. gr. The plating solution in a plating vessel 9 is supplied into a vessel providing a static mixer element 5 by a pump 10, and oxygen from an oxygen cylinder 8 is supplied from an introducing hole 2 to increase oxygen concn. in the plating solution up to within the range of 6-20ppm. The copper having excellent quality is stably plated with the electroless method without lowering the precipitating velocity of copper.