抄録
In this paper, a method for the determination of coating layer thickness by ultrasonic reflection spectroscopy is presented. This method is based on absolute measurements of reflection coefficient of coating materials and analysis of its frequency dependence. The thickness is determined from the frequency of least reflection. An experiment with seven kinds of two layered specimens (Bi/Ag on Cu alloy substrate) having different Bi layer thickness was demonstrated. The frequency of least reflection is measured for each coating at incident angle of 30°and the Bi thickness is then estimated from the measured frequency. The estimated thicknesses almost agree with those determined by SEM observation.
