Electronics Forum | Fri Apr 25 11:38:22 EDT 2008 | vortex337
Our company has run into an issue with de-wetting of lead free components. Our profile is dead on with paste manufacturers specs. We have had this issue with both gold immersed, and hot air leveled boards. We have tried three different solder paste m
Electronics Forum | Thu May 21 09:54:07 EDT 1998 | Justin Medernach
| I'm reviewing my board fab spec. It calls for a minimum SnPb thickness of 50 microinches on HASL PWB's. I've looked at other specs that call out anything from 30 to 80 microinches, and others that just say the copper pad must be covered and solde
Electronics Forum | Tue May 26 14:50:07 EDT 1998 | Dave F
| | I'm reviewing my board fab spec. It calls for a minimum SnPb thickness of 50 microinches on HASL PWB's. I've looked at other specs that call out anything from 30 to 80 microinches, and others that just say the copper pad must be covered and sol
Electronics Forum | Fri Jun 14 14:30:36 EDT 2002 | davef
Assuming you are talking about solderable surfaces: People specify various materials to protect the solderability of the pads on the board. Gold, actually, Electroless Nickel - Immersion Gold [ENIG], is popular. * Board fabricators like it because
Electronics Forum | Tue Mar 22 07:39:05 EST 2005 | davef
There is no standard. This is a relative test. If you wish to do tests of this kind, we suggest to pay attention to the following points: * Shear strength of soft solder depends on the deformation speed applied. The faster the material is deformed t
Electronics Forum | Wed Apr 26 12:38:33 EDT 2006 | TMC
I would suggest you do the following: get a sample / scrap board that you will be reflowing, attach thermocouples at various locations on the board, send the board to APS or whomever. Ask them to run a profile based on your solder pastes manufactur
Electronics Forum | Wed Feb 02 09:58:00 EST 2000 | Dave
Ashok, I don't understand what they're saying about the gray joint. Usually a gray joint has to do with too much heat. Also, the higher the temperature the lower the fillet because of the increased viscosity of the solder. Correct? Wouldn't yo
Electronics Forum | Mon Nov 04 10:14:49 EST 2002 | blnorman
We manually handle boards all the time (repair, clean misprint solder paste, etc.). The workers know to handle with gloves, but it's a rarity that they do. We also use hand lotions in the plant, and a couple of times, lotion residue has shown up on
Electronics Forum | Fri Mar 28 21:37:11 EST 2003 | MA/NY DDave
Hi Are all the other solder joints for the other components other than the MELF not having a problem. That is what you said, yet I wanted to check?? To say a less twisted way is this only with the MELFs and is it with all the MELFs?? If you have
Electronics Forum | Tue Jun 03 06:29:43 EDT 2003 | mk
Orrrrrr, you could eliminate the printing, shorting, and special surface finishes by bringing the boards in with the paste already on them. There is a process that is a much more forgiving method for applying paste called solid solder deposit. Check
.gif)
