John, Hi from from around the corner. I take Miller home heading out to the lake. IPC should only be used as a reference and not as a standard. Due to the complexity of our PCBs we do not use the pad/clearance calculation. Reference IPC-275 for the recommended pad and clearance size for a 12mil vias. Based on your design the IPC requirements will not work for you. We usually use "D + 16min/24max for planes" and "D + 10min/15max for signals." However, this works for us and may not work for your design. As of now, your pad size is to small for signal or planes. Hope this helps. John Gulley Compuroute Inc. Dallas, TX 214-340-0543 [log in to unmask] > Date: Thu, 12 Sep 1996 10:07:43 -0500 > To: [log in to unmask] > From: John McDowell <[log in to unmask]> > Subject: Via Size > What is the smallest size via that IPC allows? > > Can one use a via that is .025 pad with .012 hole size on a .062" thick > board? > > Does the Board size affect the via's pad and/or hole size? > > John McDowell > Geco-Prakla, Schlumberger > 10420 Miller Rd. > Dallas, Tx 75238 > John [log in to unmask] > > *************************************************************************** > * TechNet mail list is provided as a service by IPC using SmartList v3.05 * > *************************************************************************** > * To unsubscribe from this list at any time, send a message to: * > * [log in to unmask] with <subject: unsubscribe> and no text. * > *************************************************************************** > > *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************