| What is the industry standard for calibration compliance certification of SMT machines? and Flow Solder machines? | We are currently doing a Quality Audit on one of our manufacturing venders and this questions has been brought up. | Any help would be appreciated. | Thank you, | Vic
Vic, Thermal and mechanical calibration is traceable to supplier specification limits and that to NBS. As an example for solder pot or reflow temperatures, use calibrated thermal sensors (thermometers, moles, etc.) again traceable to NBS to calibrate applicable tools and equipment. The same is true for mechanical devices as conveyors, timers, pressure gages, hygrometers, or placement heads/positioners/lead screws/belts/encoders, etc.. Everything is traceable to the point of manufacture (machined parts using lathes, mills, etc.) and these activities to a higher authority as the National Bureau of Standards. What often is acceptable is that calibration is regularly performed, made traceable, and identified as such to a set of supplier tool, or equipment specifications through certifications. Using supplier certified specifications, calibration is performed ensuring performance within a specified range thus ensuring acceptable quality nothwithstanding uncalibratable variables as human intervention, save effective training (good or poor process management). An easy example would be calibrating conveyor speed as a function of an indicator. Using a calibrated "ruler or yardstick" and a calibrated stop watch, calibration is performed, identified as traceable, and equipment is logged and tagged as calibrated. If a conveyor speed of 4 fpm is required, simply time a conveyor mark through a one foot trap on the calibrated yard stick with the calibrated watch and ensure 15 seconds elapses. Geez, this stuff gets complicated but traceabiality is the simple answer. Earl Moon
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What is the industry standard for calibration compliance c...
- Jun 25, 1998
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