Material Spectroscopy
Non-destructive analysis of materials is necessary to verify compliance with hazardous substance regulations in electronic components. Utilizing x-ray fluorescence spectroscopy allows quality control departments to determine the elemental composition of printed circuit board surface finishes and solder alloys. This method works by bombarding a sample with high-energy x-rays, which excites the atoms and causes them to emit secondary x-rays of characteristic wavelengths.
Measuring these emitted energies reveals the presence and concentration of specific elements like lead, gold, or nickel. The analysis is completed in seconds, providing a rapid screening method for incoming inspection. This technique is also used to measure the thickness of surface finishes like electroless nickel immersion gold to ensure they meet specification limits.
Elemental Identification
Each element has a unique electronic shell structure, resulting in a distinct spectrum of emitted x-rays when analyzed. The intensity of the peaks in this spectrum corresponds to the concentration of the element within the sampled area. This capability enables the detection of lead-free compliance violations down to parts-per-million levels.
Surface Thickness
This technique can also measure the thickness of multi-layered surface finishes by analyzing the attenuation of signals from the underlying copper. This measurement ensures that protective metal coatings are thick enough to prevent copper oxidation before assembly. This verification is crucial for maintaining solderability across long-term storage.
