| 摘要 |
PURPOSE:To improve remarkably the physical properties of deposited copper by adding cyanogen ions and ammonium ions to an electroless copper plating soln. for an additive process and by adjusting the pH of the plating soln. CONSTITUTION:To an electroless copper plating soln. consisting of water, copper ions to be deposited, a copper ion complexing agent and a copper ion reducing agent are added 2.5-30mg/l CN<-> and 0.18-3.6g/l NH4<+>, and the pH of the plating soln. is adjusted to 12.0-12.5. Copper deposited from the plating soln. has remarkably superior tensile strength and elongation. When the plating soln. is used in the manufacture of a printed wiring board, the breaking of a wire in the circuit pattern of the board and the cracking of the through holes can be prevented. Said defects are caused by a thermal strain produced during the working of the board and the packaging of parts by soldering or other method. |
