Dispensed Paste Drying Time

[pathare]

When I bake my solder paste is just seems to disappear, the parts still hold but it just doesn't seem like a great solder joint. Is this normal?

I'm using the provided solder paste and baking with the default profile

[mewertow]

Hey @pathare,

If it looks like the solder paste isn't making a complete joint, I'd suggest trying to dispense more paste - this will add mass to the joint and help secure it better. If simply adjusting the flow rate with +/- doesn't do it, try the following:

1) Decrease the solder pass spacing parameter in the settings window to about 0.14-0.16.
2) Increase the solder print height to 0.16-0.18mm in the settings window, and adjust flow rate accordingly.

Let me know if that helps!

• Matt

[LulaNord]

Hi...i am a new user here. Does anybody know how long after I apply solder paste to a board I have before it goes bad and can't be reflowed? I've read about printing and abandon time but that's related to the stencil, and see numbers for things lie overall shelf life, but can't find out how long the paste is good for once it's on the board.
I've got to make 15 boards that take about 40 minutes each to populate (384 SMD components) and am trying to plan out if I can print, print, print, place, place, place, bake or if I need to print, place, bake, print, place, bake, etc.

[mewertow]

Hi @LulaNord, sorry about the long wait!

Our solder paste has a tack time of up to 8 hours in ideal conditions. For your 15 boards, populating would take about 10 hours - I'd suggest then printing and populating in 2 or more batches.

Hopefully this info is still relevant to you. Did you happen to try out populating the 15 boards?

• Matt