| 摘要 |
PURPOSE:To enhance the electrical connectibility of the through holes of a print substrate by plating the substrate while periodically applying impacts to the substrate to make plating thickness uniform even in case the ratio of the substrate thickness and the through hole diameter is high. CONSTITUTION:Print substrate 1 dipped in a plating soln. is plated while periodically hitting piston rod 4 of air piston 3 in the direction of arrow P. By the first and second impacts a fresh plating soln. enters through holes 2 in the direction of arrow Q (a) and the direction of arrow Q (b), respectively, and the old plating slon. is pushed out and refreshed. Accordingly, plating thickness in the through holes is made uniform, and the electrical connectibility is enhanced even in case the ratio of the substrate thickness and the through hole diameter is above 2. In case of above 2 the substrate is difficult to be plated by a conventional method. The im pacts are desirable not to exceed 400 times/min, and 10-200 times/min are most effective. |
