Jens Sch�nfeld wrote: > Try a hot air gun and ice spray. Thats ok for trouble shooting but not good for burn in.
If your product is small go to Wal-Mart and get one of those electric powered "ice chests", which are really Peltier Thermoelectric devices. Plug it in one way and it gets hot, plug it in the other way it gets cold. Buy or build a power H-Bridge to drive the thing and now you have a nice small thermal chamber. Used thermal chambers go for $10,000, this goes for $100. You can't get the same temp. extreams but you save the $. Unitrode did a App Note on it, which is now lost in the TI site. "Closed Loop Temperature Regulation Using the UC3638 H-Bridge Motor" http://focus.ti.com/docs/apps/catalog/resources/appnoteabstract.jhtml?abstractName=slua202a Both Linear Tech. and Maxim have come out with Peltier controller meant for LASER Diodes, but they might work for this. AMC7820REF: A Reference Design for DWDM Pump Lasers http://www-s.ti.com/sc/psheets/sbaa072/sbaa072.pdf See figure-4, just replace the LASER with "Ice Chest". Take a look at http://www.csonline.net/bpaddock/ for more links to Peltier and H-Bridge stuff. The Preface to Murphy's Law: We, the willing, Lead by the unknowing. Are doing the impossible for the ungreatful... We have done so much for so long... With so little... We are now qualified to do any thing... With nothing... Forever!... On Wednesday 04 September 2002 05:23 pm, Jeff McKnight wrote: > Does anybody have any info or sources on initial burn-in > testing of electronic products. What exactly are you testing (what is your goal)? That changes the answer to your question. The bottom line is you have to have a clear goal in mind that the one you stated so far to get a good burn in test. Are you looking for solder joint problems? Then you need to cycle thetempaturee betwen high and lows, several times. Like +75'C to -20'C. Device does not need to be powered. If your looking for infant mortality then you need to have the thing powered. The change in temp. is not that important. > in procedure. Should it be done at room temp. or at an > elevated temp ? It should be done at both extreams. Again it depends on your goals. Heat tends to age parts and kill the weak ones. Cold tends to mess up the functioning of the circuit due to dew point issues, and less frequently because it really is cold. Most would use Conformal Coating to deal with that, but keep these points in mind: Conformal Coating is NOT the same thing as a hermetical seal. Many people think that it is. Moisture WILL migrate through the coating given enough time. However you end up with pure water because the impurities in the water won't make it through due to their large molecular structure. You end up with pure water trapped on the board. Pure water is a far insulator, so it doesn't upset MOST circuits. It can effect things like static meters that have extremely high impedances. > I would really appreciate some advice on where I could find this type of > information. There are some Mill Specs. and poke around these sites: Reliability Analysis Center: http://rac.iitri.org/ http://www.ipc.org/ > A Google search turned up many contract manufacturing services, but no > specific procedural information. We would not publish such information for several reasons. Main one being that it would be to much like work. ;-) http://www.matric.com/ -- Author: Bob Paddock INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
