MK: If you are getting good product with air, here�s what you should do: * Turn off the N2. * Sell that N2 cracker machine. * Pat yourself on the back. * Go out for beers. [Not any of that Canadian Fosters crap, tho][Did you know that Ozzies don�t even drink that stuff???? Right, Dreamster????] * Live well and live long.
Now, if that�s not the correct answer, here�s some thoughts: * Is 900 ppm your N2 purge rate? What is the duration of your purge? * Is 1000 ppm your O2 maintenance level? If so, that�s approaching "thin" * Is someone turning the N2 off? * Are your N2 curtains in place and working properly?
Think about: * Checking Marc and Earl�s comments on N2 reflow in the fine SMTnet archives. Altho, there does seem to be an echoecho inin herehere * Talking to techietypes at BTU * Searching SMT Magazine. There�s at least 20 nitrogen soldering articles on their site. * "Circuits Assembly" lists the following as Top 100 Articles: - Nitrogen Atmosphere: Who Needs It? By Dr. L. Lawton July 1998 - Reducing the Cost of Inert Soldering By M. Theriault and P. Blostein July 1998 * SMTA Journal - Inerting The Wave Soldering Process With Membrane-Generated Nitrogen, C. Shea 09/12/1999 - Solderability Of Different Board Finishes Under Nitrogen Atmospheres With Different Rols, J. Tauchmann 09/12/1999 - Solderability Of Printed Wiring Boards With Organic Solder Preservation Under Nitrogen Atmosphere, T. Zachert 08/23/1998 - Technical Advance Improves Reflow Process Reliability And Consistency, B. Bailey 04/28/1997 - Reducing Solder Defects Under Nitrogen With Varying Oxygen Concentrations, H. Hsiao 04/28/1997 - Implementation And Production Test Results Of A Closed Loop Control Of Atmospheres For Soldering, N. Saxena 09/10/1996
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