Electronics Forum | Mon Aug 25 15:40:58 EDT 2008 | dyoungquist
I am seeing poor quality solder joints, mostly on 0402 components. The problem is that while the pad on the pcb is getting fully wetted, the solder is not flowing up the sides of the 0402 component, i.e. the 0402 lead is somewhat de-wetting. The re
Electronics Forum | Mon Dec 15 15:34:17 EST 2008 | dyoungquist
Sorry it has taken me so long to respond. I got pulled off onto other projects and was not able to work on the solution to the problen until recently. The solution we have come up with is to change from no-clean flux based solder paste to water sol
Electronics Forum | Sun Sep 28 17:14:53 EDT 2008 | ronsou
small pads like 0402 tend to get hot quite > easily. looks like excessive heat is your problem > here. pads are wetted, component leads are not. > this means solder paste flux on top layer was > exhausted before entering in reflow. your profile
Electronics Forum | Tue Sep 02 15:29:36 EDT 2008 | bvdl
small pads like 0402 tend to get hot quite easily. looks like excessive heat is your problem here. pads are wetted, component leads are not. this means solder paste flux on top layer was exhausted before entering in reflow. your profile is the 'in-be
Electronics Forum | Mon Jul 25 06:12:53 EDT 2005 | lloyd
Folks thanks for all the info, I'm gonna check out our pad geometries and see how they compare with industry standards. Brian, could you elaborate a bit more on the stencil design you have mentioned. Do you mean that you have offset the stencil aper
Electronics Forum | Thu Jul 07 18:16:36 EDT 2005 | russ
What size discrete components and have you evaluated your pad geometries? If pads are too far apart this will happen. The flux resudue is simply there because you didn't solder the component. It will stay on top of the solder bump. You can see this
Electronics Forum | Wed Sep 05 08:50:04 EDT 2001 | davef
No arument with others comments about moisture, but taking a different tact, consider that the volitle elements of the solder paste disppear as a function of the amount of time the paste is out of the container. [Maybe as a function of solder paste
Electronics Forum | Tue Nov 04 12:45:54 EST 2008 | smt123
Hi Martin, Have you considered printing the flux with a stencil? Stencils can be used for printing more than just solder paste. Quite regularly people use stencils for printing thermal grease, fluxes, conductive epoxy and more. The thing I like
Electronics Forum | Wed Sep 10 15:35:21 EDT 2008 | gregoryyork
Do those Balls pass IPC LOL Looks like the paste has been stored incorrectly probably stored stood upright and the flux medium has 'moved' so you have very rich flux areas and getting slumping due to it. Paste in cartridges should be stored flat refr
Electronics Forum | Tue Apr 27 19:08:04 EDT 2021 | emeto
Jerry, just out of curiosity, why can't you use flux? Flux is essential part of soldering and it is there for multiple reasons. Flux we can also clean afterwords - even No Clean.
