Chemistry Selection – How to Match Your Soil to the Right Chemistry

Can this type of testing be performed on other substrates?
Absolutely. A lot of times we get into high temperature reflow that you can’t use in FR4 boards, so in that instance we bring in copper. We’ve also done aluminum substrate testing on some epoxies, so all kinds of stuff can be used.

What temperatures are tests normally performed at?
Most of our aqueous and semi-aqueous products we run 40 and 60 C. Because of how the product are ran sometimes we have to run it at room temperature for solvents.

Do the results from this solubility test typically correlate to cleaning in a machine?
As long as you start out with a good combination between the chemistry and the soil that’s a 2 or better I would say absolutely things correlate correctly in the machine. Like I said, sometimes we have a less great match but that’s the chemistry we have to go with. We have to work with the machine and tailor that process to really get to the cleanliness that you want.

How would I have my soil tested?
Reach out to us. We are running tests every day it feels like. If we haven’t ran the soil, we can definitely work with the solder paste company and get it in and tested.

What if I have multiple fluxes on the same board?
So typically what we recommend with that is seeing what the results are with the two independently and then coming up with a good match. Sometimes it happens that we have a no-clean flux residue that responds really well with solvents and then there is water-soluble in there so customers meet in the middle and find a great one there or we have some customers that are running two products. It happens and depends on the soils.