Electronics Forum | Wed May 09 17:13:06 EDT 2007 | zanolli
Re: 63/37 paste reflow Is there a standard reccomended time (ball park) above liquidus? What are the negative ramifications if the TAL is too short or too long? Thanks in advance
Electronics Forum | Thu May 10 08:09:52 EDT 2007 | davef
There is no standard for time above liquidus. It is described rather broadly by the solder paste supplier. Reflow Zone: If the temperature is too high, boards may char or burn. If the temperature is too low, cold and grainy solder joints will resul
Electronics Forum | Fri May 25 13:38:15 EDT 2007 | mfgengr
TAL Too Long - dull solder joints, dewetting. TAL Too Short - cold solder, insufficient wetting. You want TAL to be as short as possible (but not lower than 30 seconds), but long enough for every solder joint to be above TAL for at least 30 seconds.
Electronics Forum | Tue Jun 28 17:38:13 EDT 2005 | mdang
We got the same problem. To solve it, we have to tint the pads first and do the normal reflow process. It works but take a lot of time to tint the pads. Any thoughts? Thanks, -Michael
Electronics Forum | Mon Aug 19 16:57:38 EDT 2002 | dragonslayr
Individual process steps are approximately the same length of time for reworking a BGA. You seem to be comparing the use of the automated SMT line versus an off line rework station. Consider that the off line station is a complete paste print, pick
Electronics Forum | Fri Dec 16 11:04:23 EST 2005 | chunks
Over all time will be dictated by your conveyor speed. Your conveyor speed will be dictated by your products time above liquidous. Time above liquidous is dictated by the manufacturers specification. Time and temp before reflow will have to be ach
Electronics Forum | Fri Sep 08 04:45:17 EDT 2000 | PeterB
As per Travis's reply it could be something other than the reflow process. Another good one is if the printed PCB's have been cleaned down due to print misregistration etc.. If not properly controlled paste residues can remain distributed about the p
Electronics Forum | Mon Feb 13 08:25:40 EST 2017 | emeto
It looks like you got all the paste to a liquidus stage and ten probably to a gas stage, so it is just a matter of running the mole several times.
Electronics Forum | Fri Feb 24 03:14:47 EST 2017 | rob
Deni, I would suggest N2O over straight Nitrogen, as you will immediately find your results more satisfying, and any defects will become less of an immediate concern.
Electronics Forum | Tue Feb 26 11:19:31 EST 2013 | anton99
Stephen, That's true and I am going to include the reflow time in our changeovers. That way if its taking to long to change the oven temperature it will show up in our metrics. I agree, if we miss a step in the changeover process our metrics will be
