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PCB007-July2019

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38 PCB007 MAGAZINE I JULY 2019 Feature Interview by Andy Shaughnessy I-CONNECT007 At the recent IPC High-Reliability Forum and Microvia Summit, Andy Shaughnessy spoke with Michael Konrad, founder and president of Aqueous Technologies and a speaker and pan- elist at the event in Baltimore, Maryland. They discussed Konrad's presentation and the recent proliferation of cleaning, from solely high-reli- ability products to Class 1 consumer products. Andy Shaughnessy: Good to see you, Michael. Can you start by telling us about your upcom- ing presentation? Michael Konrad: I'll be talking about the factors that influence the reduction in residue toler- ance on circuit assemblies. Historically, circuit assemblies were—almost without exception— cleaned after solder and reflow. With the intro- duction of the Montreal Protocol and a ban on the cleaning solvents that were used to remove the containment species from the circuit as- semblies, the majority of the industry switched to no-clean technologies. The hope was that this would eliminate the need for cleaning, and it largely did for a long time. Now, due to miniaturization and very mini- mal—if any—gaps between the bottom of the component and the top of the board, the amount of tolerable residue has shrunk on assemblies to the point where now most as- semblies are cleaned again. It's an evolution. I'll also be introducing the new IPC J-STD-001 Amendment 1 change to the cleanliness test- ing requirements of the J-Standard as the way the industry has responded to the sudden need for cleaning again and the consequential need to test for cleanliness. Shaughnessy: What's the change with that standard? Konrad: Much of the change has to do with resistivity of solvent extract (ROSE) testing, which was the predominant method of test- ing cleanliness for the last 30–40 years. But ROSE testing isn't going away; it's going to be used more. What is going away is the histori- cal pass-fail limit that was associated with the ROSE test. ROSE testers were used to deter- mine pass or fail, clean or dirty; now, they're How Changing Cleaning Technologies Affect Reliability Michael Konrad

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