| 摘要 |
PURPOSE:To increase the adhesive strength of a treated layer and to improve the resistance to an acidic treating soln. by forming copper oxide on the surface of copper and successively bringing the surface into contact with an aq. soln. contg. alkali borohydride and an aq. soln. contg. formaldehyde. CONSTITUTION:The surface of copper is brought into contact with an aq. soln. contg. an oxidizing agent to form copper oxide on the surface. This oxidized surface is brought into contact with an aq. soln. contg. >=about 0.1g/l alkali borohydride to change the electric potential of the surface to the range of -1,000--400mV basing on an Ag-AgCl electrode. The oxidized surface is then brought into contact with an aq. soln. contg. formaldehyde to change the electric potential of the surface to <-1,000mV basing on the Ag-AgCl electrode. Thus, an oxidized surface is obtd. with satisfactory adhesive strength at a high treatment speed. This method is applicable to the surface treatment of the inner circuit of a multilayered printed circuit board. |
