| 摘要 |
PURPOSE:To improve adhesion between a copper circuit and prepreg resin and prevent the development of a halo phenomenon by immersing an oxide coating on the surface of the copper circuit in nitric acid after performing oxidation treatment of the copper circuit provided on an inner layer circuit board to obtain cupric oxide and, in addition to turning cupric oxide of the oxide coating into cuprous oxide, making the copper circuit deposit itself metallic copper. CONSTITUTION:After electric circuits are formed on the both sides of a laminated board by using the glass cloth base material-epoxy resin laminated board clad with copper foils on the both sides of the above board, both faces are made to become slightly rough by a belt sander. Then the solution of alkaline sodium chlorite is prepared at a temperature of 50 deg.C and an inner layer circuit board is immersed in the above solution for 10min. Then its circuit face is made to become rough still more by performing oxidation treatment of the surface of the copper circuit and a cupric oxide film is formed as well. Subsequently, this circuit board is immersed in a 7% of nitric acid for 30min. at a temperature of 30 deg.C to turn cupric oxide of an oxide coating into cuprous oxide and further, makes the copper circuit deposit itself metallic copper as well and its board is washed with water is dried. In this way, surface treatment of the copper circuit not only improves adhesion between the copper circuit and prepreg resin but also prevents the development of a halo phenomenon. |
