| 摘要 |
PURPOSE:To measure the viscoelasticity of a thin film with the thickness 10 mum or below by bringing the thin film into close contact with the surface of a piezoelectric substrate, and measuring the propagation speed of the surface elastic wave in the thin film. CONSTITUTION:A crystal ST plate 14 is a single substance, and the electric signal inputted to a transmitting electrode 10 excites the surface elastic wave on the ST plate 14. The surface elastic wave reaches a receiving electrode 12 and is converted into an electrical signal, and the electrode 12 outputs it to a microcomputer MC 25. The MC 25 measures the ultrasonic wave propagation speed in the single ST plate 14 from the difference between the input and output time of the electrodes 10, 12. The sonic wave propagation speed is measured while a thin film 16 is kept in close contact with the surface of the ST plate 14 by the same method, and the sonic speed of the surface elastic wave in the thin film 16 is determined from these measured values. The rigidity of the thin film 16 is calculated by the MC 25 based on the sonic speed and the previously measured density of the thin film 16. Since the thin film 16 is brought into close contact with the surface of the piezoelectric substrate, a sample is easily held in the thin film shape, and the viscoelasticity of the thin film 16 with the thickness 10 mum or below can be measured. |
