| 摘要 |
PURPOSE:To obtain a speaker which can cover a wide area from an intermediate frequency band to a high frequency band by laminating alternately two layers or above of a diamond or diamond-shaped carbon layer and a Si3N4 film layer. CONSTITUTION:Si3N4 of 22.0mum thick is evaporated on an M0 plate by a CVD method, and thereafter, M0 is dissolved by aqua regia and a Si3N4 plate is obtained. Next, on the Si3N4 plate, a diamond film of 5mum is covered by a plasma CVD method with a micro wave of 2.45GHz as an excitation source. When the diaphragm of 50mmphi of an Si3N4-diamond laminated construction obtained by such a method is used for the dynamic type speaker diaphragm, the sound pressure level between 10KHz-20KHz is within 1.7dB of the average value. The high frequency band frequency characteristic goes to be satisfactory compared with the fact that the error of maximum 2.4dB is found for the same type Be diaphragm. |
