Electronics Forum | Thu Mar 08 22:24:45 EST 2001 | davef
Sounds like you've done a good job of troubleshooting. Two thoughts are: 1 An alternative to using a hotter flux that the others mentioned is to use components with more solderable terminations. [A firm grasp on the obvious.] 2 You spoke about
Electronics Forum | Thu Mar 15 21:29:06 EST 2001 | davef
That you can solder the test points with a little extra flux and a good blast of heat makes me think there is nothing fundamentally wrong. I'd guess there is oxidation on some test points that is a little crustier than others. You might be able t
Electronics Forum | Tue Apr 10 11:39:29 EDT 2001 | brownsj
One of the reasons for a grainy joint is the cooling of the joint after reflow. Check your reflow profile, not just the preheating and reflow section but also the cooling zones. It works the same way as molten rock. If it cools slowly you get pumice
Electronics Forum | Mon May 28 17:43:33 EDT 2001 | davef
Does this device have a integral heat sink / metal slug on top, like a TI TM320C6XXX er a Altera EP20K4XX? Compare the size of the pads on the interposer and the board. Compare the type solder mask [NSMD vs SMD] on the interposer and the board. Wh
Electronics Forum | Fri Aug 30 04:53:08 EDT 2002 | jason
Hi Dr Lee, Recently, I was assigned to use Ag imm. PCB using 63/37 solder paste without Ag. The results were not fantastic. Surface finish was rough and lots of wetting issue. The oven profile soaking time was set at 70 secs above 183�C and Max tem
Electronics Forum | Thu Jul 20 13:01:07 EDT 2000 | qsheng
What is the difference of formulation No-Clean Sn63 with No-Clean lead free paste? Is there techniocal data in detail for performance property of No-Clean lead free paste (for example, viscosity, solderability, tack, print life, reflow profile)? Is
Electronics Forum | Thu Jul 20 12:23:00 EDT 2000 | Dave F
Bob: Please help us understand the effect of changing to lead-free solder paste on our processes better. Compare the following for tin-lead and lead-free solders: * Size of stencil apertures � amount of solder necessary for a reliable solder conne
Electronics Forum | Fri May 11 10:30:26 EDT 2001 | rkevin
I am looking for info. (pro and con) and/or 1st hand knowledge processing PCB's with Immersion Tin finish through SMT and Wave. Do profiles need to be different? Solderpaste considerations? Anything else? In the past I have experienced selective non
Electronics Forum | Sat Jun 09 09:32:26 EDT 2001 | davef
Yes, your pallet will absorb / steal heat. It sounds like you are doing a good job in understanding the issues. Yes, the pallet could be the problem. Is this a new run that you are starting? Or has everything been OK, but recently you've begun to
Electronics Forum | Thu Jun 14 10:50:49 EDT 2001 | slthomas
I must be missing something.....why can't you simply attach thermocouples, profile the assembly, and adjust your zones as required to reach the parameters required by your paste and component specifications? Is there a restriction on that process fo
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