Electronics Forum | Fri Oct 19 17:09:56 EDT 2007 | hegemon
We have both DRS24 and DRS25 Lead Free rework is done for the most part on the DRS25, although the DRS24 can handle some of our smaller pbFree assemblies. We bought the DRS25 machine new, it was not an upgrade. The machine is very successful at pb
Electronics Forum | Fri Nov 09 05:15:34 EST 2007 | exar
Hi, Inm also kind of new in this matter, I had noticed that the feeder tech before me did not used the correct spare parts. He used to mix all fuji parts as one. I prefer to use silicone lubricant( it wont become sticky) Alfredo Ronda Tyco safety pr
Electronics Forum | Fri Oct 26 09:38:57 EDT 2007 | slthomas
Rather than go into detail here, try googling "classic reflow profiling". One of the guys at ECD (a thermal profiler manufacturer) wrote a pretty decent article that covers most if not all of it. You DO have a profiler, don't you, or an oven with
Electronics Forum | Sat Nov 03 09:39:27 EDT 2007 | davef
Flux exhaused or CSP never came to peak temperature * BGA balls don't combine with the solder => Flux exhaused or BGA balls never came to peak temperature * 0402 surface looks like many tin balls piled together => Flux exhaused Start your thermal
Electronics Forum | Fri Nov 09 10:15:27 EST 2007 | devajj
Of course if you are an OEM you could go back to your design engineers and tell them via's in SMD pads is unacceptable. Put that in your DFM design guidelines. If you are an EMS provider you can also influence your customer by explaining the impa
Electronics Forum | Wed Nov 07 09:19:16 EST 2007 | pjc
Could be not enough peak temp. Do you have a profiler? I'd measure at the BGA joints- drill under board to get access to BGA solder joints and embed a couple of thermocouples with hi-temp solder, then run your profile to see max. temps. and that prof
Electronics Forum | Fri Nov 09 00:40:59 EST 2007 | cadcopac
We design and assemble PCB's and use a min of .015 thou over the component lead diameter without incident but if your component pad is in a copper mass either top or bottom this can create other problems especially if you don't have top heating as th
Electronics Forum | Thu Nov 08 21:46:09 EST 2007 | davef
In the marketing description of your paste, look for "percent metal by volume." This percent metal by volume figure gives you a good approximation of the amount of metal in each solder paste brick that you print on your board. In most solder paste fo
Electronics Forum | Fri Nov 09 10:37:38 EST 2007 | devajj
We have started using QFN packages in large volume and are having problems with no-solders. We are using 6mil stencil with 1x1 paste print to pad. These also have thermal pads with thru vias that we reduce the stencil aperture by 1/4. Board also ha
Electronics Forum | Fri Nov 09 10:58:03 EST 2007 | devajj
Best I can tell (Factory is in Mexico) is no solder from paste print. I'm ordering e-fab type stencils for them hoping to get better release. Also mandating they clean after each print, rotate their paste to keep it fresh, do LSM checks each hour f
