Well Inge , you sure play hard to get ; spend midnight heating my pyrex glass plates ; depleting my chemical fridge of polymers and the precious substrates stocks . Soooo, hate to break the news to you , yo're totally sane (doesn't help hey?); mother Gaia with sea level atmospheric pressures does indeed tolerate little intrusions . No idea how far you went on heat, pressure and vacuum ; my home lab is limited ; the best results (least amount of bubbles seen under pyrex[100x magnification]) seen after heating (went to 150'C; 1/2 hour) ; vacuum (relative, 1/2h), and assembly under vacuum ; than pulled out of cylinder and clamped . Bit impractical for volumes ; but (as you know)the moment you pull it from vacuum you have all the air soup back just about instantly . But with your budget, if it is volume (Matthias caught me on wrong foot); with one or two rotational manipulators and clear cylinder you can apply the polymer on heated substrate under vacuum ; tedious (one by one, unless you'd develop in line serial movement in glass tube). Nice project ; let me know the volumes ; polymer specs , etc. I'll mail you the chamber sketch. It would be simple enough ; all the mechanics on linear slide ; with glass tube sliding over for vacuum ; say open 2 meters; closed 1 meter . Sorry not to answer specifically ; but how much of gas is in this case in the category of how many of molecules is too much when it is obviously too much . But yo' know that . You'll have to apply in vacuum , only way , not that daunting , you'll gain on bond strength on return to atmosphere as the polymer seeps back in . I'll team up if you let me (building coincidentally much longer chamber for one of my arty projects); in return you can let us know the intermittence and silver flakes conclusions . Deal ? pk -----Original Message----- From: Ingemar Hernefjord (EMW) [mailto:[log in to unmask]] Sent: Wednesday, 6 October 1999 16:36 To: 'TechNet E-Mail Forum.'; 'Paul Klasek' Subject: RE: [TN] Cold solder Coming Aussilek, if you can give me this: how much gas and water (maybe even Mango Tea) is included in a CuMo carrier with electroless Au/Ni? Size 1"x2" and 0.05" thick. We mount this carrier on a Al part by means of a polymer transfer (heat+pressure) and observe numerous gas bubbles. Brush-Wellman recommends isostatic highpressure CuMo instead with higher (nearly 100%)metal content (less voids). Alpha Metals say there is no volatiles in their transfer, they think it's the CuMo carrier that behave badly. Vacuumbake in heat may help temporarily, but a couple of hours in the assembly environment, and I think mother Gaia will put back the gas, water and tea into the structure. Insane?/Ingemar What's this non tech rumble mate ? lets get back to work : Inge, you still owe us the analysis method adopted on those intermittents you battled with (please) . I'd love to know if that dye line worked ; or whatever else . And , Kelly, the minute traces of Darjeeling tea in bulk of Jamaican rum compromised in my grog (heated capped) should not sway you to deluded assumptions. Otherwise I agree with you ; takes a seriously confused lord to "improve" otherwise decent tea with something like bergamon oil, some of us use as a solvent (orange , ok , close enough). And Swedes boil tea in milk ! As Carey says 'enough blabbering' paul PS the PCB manufacturing saga was most enlightening ; thanks fellows PPS Do you have a picture Ioan , of that "cold" joint ? Watch it Earl - that stuff'll rust your bloomin' plumbing!! For all I know, that might be what's wrong with our Aussie friend. >I resemble that remark. > >> Earl Grey is a good tea, I agree, >> Now, Joan, are you sure it's about cold soldering at all? As you describe >it could as well be dewetting. If it's dewetting, your trouble shooting can >leave the wavesolder for a while. Again, I wonder why you don't do a wetting >test on the terminals. >> Good Lunch >> Ingemar Hernefjord >> Ericsson Microwave Systems >> >> ---------------------------------------------------------------------- >> Earl and all, >> >> the soldering was a lot better before. We've always had the QA on our >back, >> checking the flux density and the settings for the problem assemblies. >> Myself, I don't recall having seen so much cold solder. >> >> The machine had been calibrated last saturday during the monthly >> maintenance, when the pot is thoroughly cleaned. >> >> It's possible that the solder mask changed, since it's darker now. >Together >> with the soldering problems we started experiencing discoloration of the >> solder mask on the solder side. But wouldn't this randomly affect any >place >> on the surface? I still get the connectors OK, with bad solder joints on >the >> caps and resistor networks. >> >> There has been no artwork change. However, could some changes in the >> materials or manufacturing of the board affect somehow the thermal mass >here >> and there? I mean, maybe the connectors drain somehow the heat from the >> adjoining components. >> >> And anyway, what on earth generates cold solder in the waving process? >> >> Ioan ############################################################## 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. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################