Transcript
Phil
Welcome to Board Talk. This is Phil Zarrow and Jim Hall. One of our listeners sent in a question.
Jim
"How can we verify that our spray fluxer is uniformly spraying flux over the entire surface of our circuit board?" And then the second question is, "What's new in the world of spray fluxing?"
I'm assuming we're talking about spray fluxing for a wave soldering machine.
Phil
Just as wave soldering is an ancient technique, so there is an ancient technique we recommend for verifying the coverage on a spray fluxer. It's the old paper test using something like litmus paper.
Jim
You're going to take a bare circuit board with no components on it. Choose a board that has through holes distributed over the entire board area. Take a piece of paper, put it on top of the board, clamp it down, tape it down, and then run that board over the fluxer. Look to see if the flux penetrates uniformly. Make sure it penetrates through all the holes.
If you have a water-soluble flux you can use a litmus paper. If you're using an alcohol-based flux, use the traditional thermal fax paper, if you can still get that stuff.
Phil
This is the most straightforward test you can do. You can actually watch it as it takes place. Beyond that, there may be some other tests germane to the particular flux you're using. I would recommend contacting the manufacturer of the wave soldering machine or certainly the fluxer system, if it's not the same as the wave soldering machine. See what methodologies they have for measuring, comparing, and calibrating that particular device.
Jim
With many spray fluxers, you can program to spray different amounts on specific areas of the board. Make sure that you understand how to program it properly. But, that being said, the foundation is, you have a sprayer that is either on or off and a transport mechanism that moves it back and forth across the axis of the conveyor. It works in concert with the speed of the conveyor to give you your coverage.
If you're not getting uniformity, there may be a problem with one of the nozzles. Every manufacturer will have maintenance procedures for checking, cleaning, and testing your nozzles. I'm sure that most manufacturers also have maintenance routines for checking the movement of your flux head.
The final question, what's new in fluxers. From my observations what's new are improvements in user-friendliness. Better controls, easier to remove nozzles, nozzles that are more reliable, that don't tend to get clogged up, that tend to give you better, more uniform coverage. Easier switch-over between different flux systems making them more reliable delivering a repeatable quality process from your spray fluxing.
Phil
So that should hopefully answer that question.
Jim
There is a lot of ways to do things, and a lot of people have had different experiences, and we thank you for sharing them.
Phil
This Jim and Phil, saying ...
Jim
Don't solder like my brother.
Phil
And don't solder like my brother.
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