Foresite, Inc.

View Original

Video Blog: Cleaning Methods

In this video blog, Eric Camden describes cleaning methods for electronic components.

Transcript:

Hi, I’m Eric Camden from Foresite, and today we’re going to talk about determining the best cleaning method for your product. The idea is to keep everything clean all the way through the process and knowing how to control the process parameters.

A lot of what I like to focus on is: first, the thermo profiling of both reflow and wave soldering - how important that is to the end cleanliness of an electronic assembly; second, the wash process (if there is one) for water soluble fluxes - how important, how critical, all the parameters are. So it’s very much puzzle pieces that go together - in the end you have nice, clean, reliable electronics. But there are so many things along the way that have to be controlled and maintained to make that happen. There is not one thing that’s more important than another, really. Everything is equally important because in the end, your electronic assembly is only as reliable as the processes it goes through.

The vast majority of what we do is in-house, at Foresite, but we’re also able to go on-site. If a client has their own cleaning equipment, we can go in and optimize the cleaning equipment and train the operators to actually do the recovery cleaning themselves. We’ve done that a number of times around the world where a client has to bring in one piece of equipment or another to do some recovery cleaning that they haven’t been set up to do - we can teach them to do it on their own.

We have an Aquastorm 200 inline cleaner that’s really been our workhorse for the last 10 years here. Last year, we added a new Technical Devices TB18 inline cleaner. Those are our two main pieces of cleaning equipment. We also have a Tsunami batch cleaner which we use for small production lots. What sets us apart from other cleaning services is the fact that we use a hand held steamer to clean under components, adding additional energy that is necessary, especially when working with today’s no-clean fluxes. With the high rosin content, they are very hard to solubilize in a standard inline cleaner, especially if you’re only using deionized water (DI). If you’re not using a saponifier, you really need the additional, secondary form of energy to remove all of the residues, especially from underneath low stand-off components - to make sure the assemblies are clean and reliable.

Water has a very high surface tension compared to a DI-with-saponifier wash, making the use of steam critical as a secondary form of energy. DI water alone will, a lot of times, allow no-clean fluxes to create a dam around low stand-off components. The problem becomes that the water will flow across the board and actually go around some of these components instead of cleaning underneath them. So, if we’re able to take a board and soften the residues with a good DI wash, then we use the hand held steamer and actually push the rest of that softened flux residue from underneath components – like your micro BGA’s; your QFN’s. A lot of the issues that we’ve seen in the industry are because these low stand-off components are not being completely cleaned with a standard inline wash process.

So, 10 years ago we developed the hand held steam operation that’s been very effective at recovering electronics after production cleaning. The steam has really shown itself to be ultra-valuable thermal energy that’s required to clean these boards.

 

Note: Transcript edited 12/11/14 for clarity.