日本語
Hi All, I received a batch of boards and solder paste that used on it is Lead Free type.
I noticed that on some ICs solder joint is nice and formed a fillet, however on some other ICs on the same board it is a bit clumpy. The thing is that everything seem to function fine.
I know that lead free solder is known for non-slick appearance but I wanted to ask if this look of a solder joint considered normal? Attached are two pictures, you can see that one one fillets are more pronounces than on the other one.
I can reflow it but if this is normal I rather keep board clean.
- Comments(1)
A****min
Sep 03.2019, 17:08:22
Decent lead free solder should looks just as smooth as leaded, different fluxes will affect how shiny it is.
Your "clumpy" image is probably soldered OK but something isn't right, the solder fillet would be slightly concave, smooth and spread out onto the rest of the pad. instead as you say this paste appears to have tried to pull into a ball. I would suggest at the very least the profile wasn't great but possibly the paste was old and the flux no longer doing its job.
