SRC Forum - Message Replies
Forum: Reliability & Maintainability Questions and Answers
Topic: Reliability & Maintainability Questions and Answers
Topic Posted by: Reliability & Maintainability Forum
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998
Posted by: Ruby
Date posted: Mon Jul 30 13:08:41 US/Eastern 2001
Subject: Space Between Two Lines
Are there any guidelines or standards about the pad space between two high voltage lines? The voltage is around 180V. Thanks in advance.
Subject: Circuit Design Rules
Reply Posted by: B.W.Dudley
Organization: Reliability Analysis Center
Date Posted: Tue Aug 7 10:16:26 US/Eastern 2001
Design guidelines for line and pad spacing are detailed in IPC (Institute for Interconnecting and Packaging Electronic Circuits) 2221 and 2222. The standard says the minimum distance is determined by the formula of 0.1968 mil / volt. Therefore, for your example of 180 volts, the minimum distance is 0.035 inches. Good designs allow for extra clearance, as the one should counter the possibility of dendroidal growth of the metal lines and pads. Another source of information on circuit board design is MIL-P-55110D Printed Wiring Board military specification.