hi, under stress, teflon will move, ie 'cold flow'. if you were to use it, for example, as a wire wrap wire and you passed it such that it passed by, under tension, a wire wrap post, the teflon would most likely cold flow and allow the wire conductor to electrically connect to the wrap post. similarly, if a jumper wire is passed by the edge of a lead for example, and is under tension, the teflon insulation will cold flow and allow the conductor to short against the lead. kynar insulation is much more resistant to cold flow. phil -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Ken Patel Sent: Tuesday, November 09, 2004 4:12 PM To: [log in to unmask] Subject: Re: [TN] Jumper Wire - Better insulation? I never heard "cold-flow" word in my life (I am not EE!!??). Can someone explain this to me? Re, Ken Patel -----Original Message----- From: COOKE, ROBERT W. (JSC-NX) (WGI) [mailto:[log in to unmask]] Sent: Tuesday, November 09, 2004 8:31 AM To: 'TechNet E-Mail Forum'; 'Ken Patel' Subject: RE: [TN] Jumper Wire - Better insulation? Ken, For our applications, jumper wires are specified as solid, Teflon-insulated, silver plated copper conductor (i.e.: wire wrap wire), although jumpers less than 25mm (0.984 in.) may be uninsulated, provided the jumper is not liable to short between lands or component leads, or cross over traces. Type EE Teflon is rated at 1000V, +200C Type E Teflon is rated at 600V, +200C Type ET Teflon is rated at 250V, +200C Standard kynar-insulated wirewrap wire, which has long been used as jumper wire, is rated at 300V, +125C, and has good abrasion and cut-through resistance. Tefzel is rated at 300V, +150C, and has good abrasion and cut-through resistance, though cold-flow could be an issue. If you have a design that routinely requires shorting / bridging links or jumpers to hardwire-select options on the circuit board, there are zero-ohm resistors available that are compatible with pick-and-place machines. They are fairly expensive (compared to a regular resistor), but are required by some customers that don't trust a piece of wire, and don't want to see any thing on the board that looks "added". Regards, Bob -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Ken Patel Sent: Monday, November 08, 2004 5:44 PM To: [log in to unmask] Subject: [TN] Jumper Wire - Better insulation? What different kind of jumper wire is available besides KYNAR as my boss is looking for something thicker/better insulation than KYNAR? Re, Ken Patel --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------