| 摘要 |
This publication discloses an acoustically active element formed in a multi-layer circuit-board structure ( 20, 22, 24, 25 ), a method for manufacturing it, and a multi-layer circuit-board structure. The acoustically active element includes an internal chamber ( 21 ) and a membrane ( 18 ) or beam arranged in connection with the internal chamber ( 21 ), which acts as a vibrating element and is connected electrically to external circuits, in order to produce or measure an acoustic effect. According to the invention, the resonance chamber ( 21 ) is formed inside the multi-layer circuit-board structure ( 20, 22, 24, 25 ), in connection with the process of manufacturing the circuit board. |
