I vote to remove them all, thought the archives may have more information. We build boards to military 55110 and IPC class 3 here. We prefer to remove all of the non-functional pads on the internal layers. If the spacings are tight (under 6 mils for us), removing the internal nfp's decreases the chance of shorts. It can also helps the drilling department out which can be a factor if you have thousands of small diameter (less than .0135 drill bit for us) holes. Steve Underwood Engineering Manager Circuit Center, Inc. 4738 Gateway Circle Kettering, Ohio 45440 937-435-2131 ext. 127 937-435-7698 fax [log in to unmask] :-) -----Original Message----- :-) From: TechNet [mailto:[log in to unmask]]On Behalf Of Hiteshew, Michael :-) Sent: 09 January, 2001 11:49 AM :-) To: [log in to unmask] :-) Subject: [TN] Unused Inner Layer Pads: Remove or Not? :-) :-) :-) Hi, :-) I have a pcb design with two fine pitch through :-) hole connectors. In :-) order to route between pins on inner layers I need to :-) remove unused inner :-) layer pads on that connector. :-) Here's my question: from a production point of :-) view, is it better to :-) selectively remove only those pads necessary or remove all :-) unused inner :-) layer pads (or is there no difference?). This pcb will be :-) manufactured IAW :-) IPC-2222 class 3. It's operating environment will be 0 - 70 :-) degrees C; no :-) thermal shock anticipated. :-) :-) :-) Michael Hiteshew :-) Lockheed Martin NE&SS Marine Systems :-) [log in to unmask] :-) (410) 682-1259 :-) :-) ------------------------------------------------------------ :-) --------------------- :-) Technet Mail List provided as a free service by IPC using :-) LISTSERV 1.8d :-) To unsubscribe, send a message to [log in to unmask] with :-) following text in :-) the BODY (NOT the subject field): SIGNOFF Technet :-) To temporarily halt delivery of Technet send the following :-) message: SET Technet NOMAIL :-) Search previous postings at: www.ipc.org > On-Line :-) Resources & Databases > E-mail Archives :-) Please visit IPC web site :-) (http://www.ipc.org/html/forum.htm) for additional :-) information, or contact Keach Sasamori at [log in to unmask] or :-) 847-509-9700 ext.5315 :-) ------------------------------------------------------------ :-) --------------------- :-) --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------