Patent ID: 8815072
Filing Date: 2014-08-26
Classification: C25D,C25F,H05K,Y10S,Y10T

Abstract:
1. A method of producing a copper plate with a roughened surfaces through forming protrusions in fine bump shapes on opposing surfaces of the copper plate to roughen the surfaces, comprising the steps of: arranging one pair of positive electrodes to face each other in an electroplating copper solution; arranging one pair of negative electrodes to face each other in the electroplating copper solution in parallel to the positive electrodes, arranging the copper plate between a pair of said electrodes; and performing more than one cycle of an anodic treatment and a cathodic treatment to form protrusions in fine bump shapes having grain sizes not larger than 10 μm, said anodic treatment forming copper particles on both opposing surfaces of the copper plate through an electrolytic process with the copper plate as a positive electrode arranged between the pair of negative electrodes, said cathodic treatment being performed after the anodic treatment by relatively moving the copper plate from between the pair of negative electrodes to a position between the pair of positive electrodes for fixing the copper particles to the surfaces of the copper plate through copper electroplating with the copper plate as a negative electrode, wherein said anodic treatment in each cycle is performed through applying a direct current to the copper plate for three minutes to ten minutes, and said cathodic treatment in each cycle is performed through applying a direct current to the copper plate for three minutes to ten minutes.