Acid to Alkaline Cleaning Agents – Where Do They Fit?

It’s all about the chemistry.
–Jody Saultz

How long does a bath last in an inline cleaner with an engineered cleaning agent?
Well, I mean, that’s a tough question to answer because whether it’s a good cleaning agent or an engineered cleaning agent, it’s going to depend on production levels. I can tell you that you’re going to probably double the life of your bath with a good engineered balanced cleaning agent versus just a neutral cleaning agent. However, those chemistry companies are out there, and they can help you determine bath lives. Which should determine how long that bath last for you.

How do you determine when a bath is loaded with flux?
Well, unfortunately, some customers run until they start getting loaded with flux residues. It then starts going from alkaline to neutral, to the acidic side. You start getting a lot of foam. Unfortunately, that’s when some customers change that out. The best way to actually determine bath life or how long it’s going to last is to get your chemistry companies to help you do some NVR testing. It basically measures nonvolatile residues and they can help you determine bath life based off some tests that they can run through each month.

Can you mix different chemistries together to get better cleaning?
I’m sure it has been tried, but I would not recommend it. Different ingredients are put in different formulations for different chemistries, and I know for a fact that different solvents are going to react with each other and you’re probably going to get some really negative responses from the chemistry on your products. So, I would not recommend doing that. I would say the answer to that is absolutely not.

What is the typical concentration percentage for cleaning flux from a pcb?
Well, in today’s world, most customers run between 10% and 15%, and some chemistries are reformulated to run a little bit less than that versus an alkaline chemistry that you have to run at 20% to 25%. So, with this balance, a mild alkaline chemistry that’s out now, you can easily run between 10 to 15% easy.