Importance of Cleanliness in the Production Process

Jim Shaw, EVP of Engineering at Crystal Group, discusses the importance of cleanliness in the production process.

Importance of Cleanliness in the Production Process

Hi, Jim Shaw here from Crystal Group.  Spending a moment just talking about the importance of cleanliness and the processing of the product as we move through the factory. It’s critically important when you’re taking COTS and you’re actually extending its performance using ruggedization techniques that you have clean, dry assemblies prior to processing. One of things that we are able to do is actually do board wash prior to any kind of secondary processing, whether that’s soldering or whether that’s conformal coating. This machine basically, it’s sort of like an industrial dishwasher on steroids. It has a lot of filtering in it so it takes the impurities out.

In essence it cleans things like residual flux or any kinds of contaminants off the board prior to secondary processing, conformal coating, board wiring modification or things like that that are necessary. And that’s one of the things frequently is necessary when you using COTS applications you do have to do some modification. Just a note, any time that we modify the board obviously the board supplier, if it is purchased, that voids the warranty. We go ahead and extend that warranty for a minimum of five years and we cover that cost. So that is one of the advantages of that system is that we can actually modify it and extend the warranty.

And then it really does what the customer needs it to do. After the boards get washed then we actually have a drying phase where we can go in and we pull a, this is a vacuum oven so we can slowly bring the temperatures of the boards up and then pull a vacuum on them, you’re essentially drying them. That’s kind of critical depending on what it is you’re doing next. We do a lot of board processing here where we design the entire boards, then they go through screen print, then pick and place, chip shooters and then BGA attachment. But before you go and get everything going through the reflow oven, you really need to have an extremely dry laminate otherwise you’re not even get blistering.

So that’s another thing that we’ve added to our repertoire here is really the vacuum oven. And if you are going to be a certified AS9100 supplier, that’s the kind of approach that you need to take. This is an example of our Heller, seven stage convection reflow oven. This is relatively new equipment but this basically takes the boards that we have stuffed and then reflows the solder. It’s a very specialized process in that it is staged. So it’s a seven stage system. It essentially slowly brings the temperature up. It brings the temperature up above liquidus for a certain period of time for the solder, and then gently cools it down.

And that’s kind of critical to a consistent, reliable solder joints so that you can maintain ISO or AS9100 Standards for not only for the solder joints but making sure boards are taken care of. Great capability to have in a small company and that’s another thing that we have here to offer for our customers. Thanks a lot.