Charles, Man, do you ever get some interesting things to do! I unfortunately don't have a lot to offer except for a few small things. 1)Under #1 do you mean Pd/Pt/Au? This could explain the dull color. We (and others) have found soldering palladium plated leads with no-clean fluxes is very flux dependent -some chemistries will do it and others don't. We're not sure what the difference is, just go by empirical results. 2) If you have a choice, pick door number 2, sounds like a much more typical coating (IGON?) and the pads sizes are better. 3) If at all possible I would preheat that ceramic if you can. Application of that much heat to such a small area of a thin ceramic is inviting trouble. I hope you get a lot more help on this one. Good luck! Bev Christian Nortel >---------- >From: Charles Barker[SMTP:[log in to unmask]] >Sent: Wednesday, November 05, 1997 4:35 PM >To: [log in to unmask] >Subject: [TN] Assy: Hi Temp Soldering to pads on Ceramic substrate > >Charles Barker@IO-US >11/05/97 03:35 PM > > We have been asked to run some tests to establish procedures for >attaching leads (24-28 AWG, teflon insul. tinned CU, stranded) to ceramic >substrate material 0.025" thick. We have a few sample pieces of ceramic >with the two different "pads" on them to test with. I do not want to start >out down the wrong path and destroy the samples. > The following is information I have received from the Engineer in >charge of this project: >1. The first substrates have a Pl/Pt/Au metal, about 0.001" - 0.003" thick. >(Looks dull as all get-out to me and quite thin-closer to the .001" >thickness.) (Small pads on my samples, about 0.063" square.) >2. The second substrates have a thick film metal covered with 0.005" thk >Cu, with 150 microinches typ of Ni, covered with 5 - 10 microinches of Au. >I don't think that the type of thick film metal matters because of the >copper. (Large, roomy surfaces to solder to on the samples.) >3. The solder spec calls out a 5% Sn, 94% Pb, 1% Ag for the high >temperature solder (HMP). (Liquidus around 300 deg C.) > >For any of you that have worked with this type of material before: >1. Any recommendations or suggestions about soldering iron temperatures, >dwell time, etc. >2. What about suggested fluxes? (I don't believe the solder we are getting >is cored.) >3. Any special tricks or techniques? >4. Should we try to pre-heat the ceramic? (This may not be possible with >the finished product.) >5. Does anyone have any pull-strength data they might be able and willing >to share? > >Many TIA's > >Charlie B. > >############################################################## >TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c >############################################################## >To subscribe/unsubscribe, send a message to [log in to unmask] with following >text in the body: >To subscribe: SUBSCRIBE TECHNET <your full name> >To unsubscribe: SIGNOFF TECHNET >############################################################## >Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional >information. >For the technical support contact Dmitriy Sklyar at [log in to unmask] or >847-509-9700 ext.311 >############################################################## > ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################