A supported hole would be one, such as a via, where the barrel is "supported" on either side of the board by a pad. An unsupported hole would be one in which there is a pad on one side only, and that pad is generally larger than if it were a supported hole. Unsupported holes are used primarily on through hole devices. Hope this helps -----Original Message----- From: Peter Lee [mailto:[log in to unmask]] Sent: Tuesday, June 25, 2002 3:22 PM To: [log in to unmask] Subject: [TN] Definition of Suported/ unsupported hole Technet, Can anyone explain the difference between a supported and unsupported hole on PCB? I am reading a section on IPC-A-600 RevF and section 2.10.3/4 specify difference acceptance criteria according to the hole type. Rgds, Peter ---------------------------------------------------------------------------- ----- 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 e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/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 e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/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 ---------------------------------------------------------------------------------