The reason why X-ray fluorescence (XRF) coating thickness gauge can become the "all-round quality sentinel" of modern electronic manufacturing industry lies in its unique ability of single measurement and dual dimensional analysis. It does not conduct two independent tests, but rather obtains all key information at once through deep intelligent analysis of X-ray fluorescence spectra generated by the same excitation.
1、 Principle basis: One excitation, full spectrum capture
When the X-ray tube of the instrument emits high-energy radiation to irradiate the sample, it will excite all elements in the sample (whether it is Zn, Ni, Au in the coating, Cu, Fe in the substrate, or potentially harmful elements such as Pb, Cd, Hg, Br, Cr, etc.) to produce their own characteristic X-ray fluorescence. The detector will synchronously capture and generate a complete energy dispersion spectrum. This spectrum is a 'treasure trove of raw data' that contains all the signal information.
2、 Coating thickness calculation: based on strength thickness model
For coating measurement, the instrument software will call the calibration model pre established for the "coating/substrate" system. The core of the model is the mathematical relationship between characteristic X-ray intensity and coating thickness. By accurately analyzing the characteristic peak intensities and ratios of coating elements (such as the L α line of gold Au) and substrate elements (such as the K α line of copper Cu), the software can use the model to accurately calculate the thickness of the coating. For multi-layer coatings such as Ni Pd Au, the algorithm will decouple calculations layer by layer.
3、 Screening of harmful substances: qualitative and semi quantitative based on characteristic peaks
In the same full spectrum, the software will synchronously scan the characteristic X-ray peak positions of harmful elements controlled by instructions such as RoHS/ELV. For example:
The appearance of lead (Pb) forms a peak at its specific energy position (such as the L α line at approximately 10.55 keV).
The characteristic peak of cadmium (Cd) is approximately 23.17 keV.
The presence of bromine (Br) (possibly from flame retardants) is shown at 11.92 keV.
The software can achieve rapid "screening" by identifying these characteristic peaks and performing counting (intensity) analysis. Although desktop XRF can perform high-precision quantitative analysis for homogeneous materials, for coatings or complex components, the screening results for harmful substances are usually semi quantitative (providing judgments of "pass", "warning" or "fail" and approximate concentration ranges), which is sufficient to meet the needs of supply chain control and rapid compliance screening.
4、 Technological advantages and value
The core advantage of this synchronous measurement lies in efficiency and correlation: within seconds to minutes, the operator not only knows whether the coating thickness meets the standard, but also can immediately determine whether the coating or substrate contains harmful substances prohibited by regulations. This provides an efficiency improvement for incoming inspection (IQC) and production process control (IPC) in fields such as electronic and electrical products, automotive components, etc., ensuring that products meet both functional requirements and global environmental regulations, truly realizing the concept of "one machine for multiple uses, one measurement for multiple functions".