Electronics Forum | Thu Mar 20 14:17:39 EST 2003 | MA/NY DDave
Hi I don't think I will enter this too much except for one of your questions. YES multiple reflows affect reliability. Heck most everything affects reliability. Aggressive Heat cycles or Heat always affects the final MTBF reliability number. The
Electronics Forum | Wed Mar 19 21:01:49 EST 2003 | Rob
I would suggest creating a special reflow profile, heating the board up to 130C about 50 c below eutectic point (183C). Then applying heat to only the BGA, this will prevent thermal shock to surrounding components.
Electronics Forum | Tue Oct 04 12:49:59 EDT 2005 | patrickbruneel
The amount of times the tin/lead solder can be melted and solidified is unlimited and the heat cycles do not affect the solder characteristics. The only reason for changing the solder pot is when impurities are at or over the maximum levels.
Electronics Forum | Tue May 27 10:34:30 EDT 2003 | davef
Much of the ability to survive rework or thermal excursions is dependent upon the fabrication materials. The board qualification criteria under the 55110 was designed around 5 thermal heat cycles. Consider reworking a BGA in this context. BGA i
Electronics Forum | Tue Aug 17 16:14:31 EDT 2010 | davef
heat cycl*
Electronics Forum | Fri Dec 16 08:16:41 EST 2005 | davef
Heat cycles deplete the pure tin layer. Each solder cycle reduces the tin thickness by ~0.1 micron (4 uin). So, if you start with a thin imm tin coating you'll have problems after multiple heat cycles. Steve Wentz says, "In almost every case I've
Electronics Forum | Tue Nov 21 12:35:59 EST 2006 | CK the Flip
It probably depends on the Silver content. We are also using Sn62Pb36Ag2. The paste manufacturer told us that the reason for the small silver content was so that it could wet better to the lead-free component and board finishes bearing silver.
Electronics Forum | Fri Apr 18 18:06:47 EDT 2014 | davef
Methods that can reduce the wettability of OSP: * Previous heat cycles * Previous cleaning cycles * IPC-1601 "Printed Board Handling and Storage Guidelines" says do not bake prior to soldering * Using improper handling methods BR ... davef
Electronics Forum | Wed Nov 19 19:28:59 EST 2003 | bwet
We are looking for recommendations on reliability testing (thermal cycling, vibration, etc.) of BGAs AFTER being soldered to a PCB. Are there any standards that include such things as heating cycles (like a minimum of 5,000 cycles), ball-ball leakag
Electronics Forum | Wed Mar 15 10:44:51 EST 2006 | Jim
How long is each heating cycle? Can you provide dimensions on the cards in a rack? In other words, what is the loading area you are looking for(LxWxH)?
