Electronics Forum | Fri Jan 24 11:05:38 EST 2003 | johnw
I fyour just using Sn/Pb in your paste even using nitrogen will lave you with slightly grainy joints. The silver from your PCB will disolve into the Sn/Pb at 'uncontrolled' rate what I mean is depending on the temperature and time above liquidous the
Electronics Forum | Fri Jan 24 19:19:11 EST 2003 | MA/NY DDave
Hi Don't really know what "your grainy" means. It could be good, marginal, or bad. You need to get some photos or micrographs of what is normal and off-normal. Compared to Sn/Pb 63/37 on mostly Sn it should look visually different. Every time you c
Electronics Forum | Sun Jan 19 10:45:04 EST 2003 | davef
For laminated FR4 PCB, we bake between 6 and 24 hours at 100�C. [Search for other bake recipes in the fine SMTnet Archives.] Alot of the determination of baking time is a function of: * Amount of moisture absorbed. * Amount of moisture you need to r
Electronics Forum | Fri Jan 17 09:38:20 EST 2003 | Grant Petty
Hi, We have a BGA that uses .4mm diameter PCB pads on the BGA itself, however we have decided to use .5mm pads on the PCB, to help paste release from the stencil. Is this a bad thing, having different size pads on the PCB compared to the BGA itself
Electronics Forum | Tue Jan 21 11:11:07 EST 2003 | slthomas
OK, so the issue is with the variability of the alloys on the soldering surfaces and the subsequent variability of reflow temps. Sounds reasonable (actually obvious, now that I think about it), especially on the component side. We only use HASL fin
Electronics Forum | Thu Jan 23 15:56:51 EST 2003 | MA/NY DDave
Hi Well I can't argue too much with MikeKonrad, whom I might know, yet maybe don't. The only other reason that you can be a little sloppy is if your product application or life cycle won't allow the corrosive cycle during usage to become a problem.
Electronics Forum | Fri Jan 24 09:04:54 EST 2003 | russ
How are these connectors and dips oriented? If the leads are parallel as opposed to perpendicular to to the wave this can promote bridging depending on spacing and length. The long leads showing icicling are most likely either inadequate heat OR the
Electronics Forum | Fri Jan 31 14:33:37 EST 2003 | joeherz
Dave, I do have the mechanical drawings but no electronic versions. After looking at the cost of setting up for N2 I decided against it for now, BTW. If you think about it, having an air knife on this nozzle would tend to negate the negative effec
Electronics Forum | Fri Jan 31 13:55:56 EST 2003 | MA/NY DDave
Hi I hope I am on point based on my reading. The outer edges bow spec depends on a gradual deformation that finally builds up to the outer edges. If you mathematically move this deformation back you will have allowable deformation at the point you
Electronics Forum | Fri Jan 31 05:18:10 EST 2003 | reg
We have a customer who is going to be using the new Snapshot process. Has anyone used this process all ready. Who did you use to make the tooling etc. Was there any problems that arose during this process. The process involves screening balls into s
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