| 摘要 |
PURPOSE:To produce a multilayered printed circuit board having superior resistance to hydrochloric acid and an electroless plating soln. by forming an oxide film on the surface of a copper sheet as a printed circuit board for the inner layer and by reducing the oxide film while in contact with a specified metal so as to pretreat the copper sheet. CONSTITUTION:When a multilayered printed circuit board is produced, a copper oxide film is formed on the surface of a copper sheet as a printed circuit board for the inner layer by spraying a treating soln. contg. an oxidizing agent such as sodium chlorite, potassium persulfate, potassium chlorate or potassium perchlorate at 55-95 deg.C. The copper sheet is then immersed in an aq. soln. of >9pH contg. a compd. such as formaldehyde, paraformaldehyde or arom. formaldehyde and the copper oxide film is reduced by contact with a rubber roll having a plated layer of Cu or a nobler metal than Cu, e.g., Au, Pt or Pd. |
