| 摘要 |
PURPOSE:To obtain a diaphragm having low cost and performance of mass- production regardless of good frequency characteristic and high electroacoustic efficiency by using a new aluminum nitride film. CONSTITUTION:A highly elastic diaphragm is constituted by forming directly an aluminum nitride film 2 on one side of a light metallic base 2 such as aluminum. The aluminum nitride film 2 is formed by taking an aluminum metal as a target, arranging oppositely an aluminum base formed into a prescribed shape and attaching directly the aluminum nitride film 2 on the aluminum base 1 by the DC or high frequency sputtering method in nitrogen and argon atmosphere as mass-production. Further, the thermal expansion coefficient between the base 1 and the film 2 has no difference, no internal distortion exists and the bonding strength of the film 2 is strong. Since the density of the film 2 is small and the sound velocity C is large, the highly elastic diaphragm having a good frequency characteristic and high electroacoustic efficiency is obtained. |
