Electronics Forum | Wed Apr 13 12:10:47 EDT 2022 | winston_one
Hello! We have a strange effect. Some pads of big trough-hole DDR slot just dessapear. Initialy it was soldered with selective soldering process (leaded, 290 degrees, ImSn finish, very short storage). Then some connectors with poor barrel fill we hav
Electronics Forum | Mon Nov 27 17:44:10 EST 2000 | Dave F
Gawd. Sure FR-4 will meet those conditions. Tg [check the fine SMTnet Archives for discussion on Tg] of FR-4 is 130�F or so. Consider: * Is the delT between Tg and the upper operating [or storage] temperature acceptable for your application? * D
Electronics Forum | Tue Dec 16 09:01:52 EST 2003 | tds
What model is your Hollis? Does it have the coil heater?
Electronics Forum | Tue Dec 16 21:17:48 EST 2003 | Peter
Maybe you fixture is too large for your product. If so, please redesign your fixture
Electronics Forum | Wed Dec 17 06:50:51 EST 2003 | ex maintain leader
140..155 degrees celsus the limit is your inserted component temp schock tolerance
Electronics Forum | Tue Dec 16 11:39:33 EST 2003 | davef
Sounds like your preheat temperature controllers are out of adjustment. Check your operating manual for instructions.
Electronics Forum | Tue Dec 16 14:26:33 EST 2003 | russ
Has anyone possibly moved the location of your thermocouples? if not check the calibration of your temp controllers/ thermocouples. Russ
Electronics Forum | Wed Dec 17 14:39:18 EST 2003 | Dean
How do you know your profiler is correct? Do you have a pyrometer you can verif the PCB temp with?
Electronics Forum | Fri Dec 19 16:58:47 EST 2003 | rontdc
Kev, If I remember correctly, Hollis used calrod preheaters on that machine and they had a reflector under the elements to reflect the radiant waves back to the PCB. You might want to clean the reflector. If it is too far gone, use some Reynolds Wr
