Subsystem Change Thresholds and Process Modification Controls
Engineering change thresholds lock Form, Fit, and Function boundaries to prevent unannounced factory alterations from voiding certifications and degrading yields.
X-Ray Fluorescence Inspection
Meaning
Non-destructive material analysis techniques determine elemental composition and surface coating thickness by measuring secondary X-rays emitted from irradiated samples. Quality assurance laboratories perform x-ray fluorescence inspection to verify metallic plating layers, lead-free solder compliance, and component termination alloys without damaging test specimens. Primary X-ray beams excite inner shell electrons, causing atoms to emit characteristic fluorescent energy signatures unique to each element.
The physical inspection boundary covers surface coatings and thin metallic layers down to sub-micron depths.
Elemental Analysis
High energy photons hit sample target atoms, ejecting inner shell electrons and triggering energy emissions. Quality control systems use x-ray fluorescence inspection to identify metallic alloys and screen incoming component terminations. Spectrometers detect secondary emission peaks to establish precise chemical composition percentages across target areas.
Plating Measurement
Surface treatment verification requires non-destructive thickness testing across contact pins and circuit board pads. Test equipment applies x-ray fluorescence inspection to measure gold, nickel, or tin plating thickness on electronic connectors. Fluorescent intensity scales proportionally with coating thickness, providing fast quality data during receiving inspection.
Compliance Verification
Environmental regulations limit hazardous material usage in electronic assembly processes. Environmental testing protocols rely on x-ray fluorescence inspection to screen incoming components for restricted substances like lead, mercury, cadmium, and total chromium. Rapid non-destructive screening prevents contaminated hardware lots from entering production assembly lines.
Discrepancies identified during initial screening trigger secondary wet chemical testing for definitive legal verification and supplier claim processing.