To put this in context, most flex circuit laminates are UL rated to operate at 105C continuously. If the device operates at 60C then a 45C rise above background is about all you should ask for. A few high performance materials are rated for 150C and 160C, so you can push things a little harder. The polyimide films by themselves (not in laminate form) can take up to about 220C continuous. Andy Magee - Applications Engineer Rogers - Circuit Materials Tel: (602) 917-5237 Fax: (602) 917-5256 E-Mail: [log in to unmask] Website: http//www.rogers-corp.com/cmu //////////////////////////// // SERVICE TO THE LINE, // // ON THE LINE, // // ON TIME. // //////////////////////////// ______________________________ Forward Header __________________________________ Subject: temp rise (current) Author: Dan Lorinser::(LRNSRD) at ~FABRIK Date: 1/29/97 6:52 AM From: Dan Lorinser Date: Wed, Jan 29, 1997 6:52 AM Subject: temp rise (current) To: Andrew P Magee; TechNet Can we talk about the temp rise? You say a 45 deg C rise may be to extreme...if i'm using an all Polimide material, dosen't this material have a high glass transition range (TG), so I could go on past 45 deg? I do split traces, but would rather use 3 oz. copper in this application. My flex needs to bend one time, it could even stay bent. All i'm doing is replacing a wire harness. Is there something out ther like a wire bonded on a flex? ======================================================= A 45 deg delta may be to extreme even if the laminate is able to withstand it. What we have done is split the trace. This is part of what note 5 in the IPC-D-275 hints at. Ten 10 mil traces are as good as one 100 mil trace. Also be careful of the copper weight. An easy way to carry more current is to use a heavier copper but in a flex circuit the key word is "flex". It's hard to bend a bus bar. We try not to use anything greater than 2 oz. Good Luck Michael L Vaughan Lockheed Martin Astronautics Denver Colorado (303) 977-7959 [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. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************