| 摘要 |
<p>The method is used for punching a precision hole in a metal-clad printed circuit board, in which the circuit board is supported between the punch and a die with a difference in diameter of the order 13 to 15% of the thickness of the board. The punch is moved towards the die so as to remove a part of the metal and the insulating board, simultaneously drawing the metal into the opening to line the hole. The method may be applied to produce a rotary printed circuit switch, in which the rotor is mounted in a lined hole punched in this fashion, and the individual contacts are separate metal areas on the base.</p> |
