Abstract: The present invention relates to an miniature actuator especially suitable for hearing aid applications. The actuator according to the present invention operates according to the change in reluctance principle. In particular, the actuator according to the present invention operates in a balanced configuration comprising two planar coils, two magnets, a membrane and a spacer chip providing the necessary back chamber volume.

Abstract: The present invention relates to compact solid state silicon-based condenser microphone systems suitable for batch production. The combination of the different elements forming the microphone system is easier and more economical to manufacture compared to any other system disclosed in prior art. In addition the invention is compatible with electronic equipment manufacturing processes, such as SMD pick and place techniques. The invention uses a transducer chip comprising a chamber, a diaphragm that is positioned at the first lower surface and covering the second opening of the transducer chip. The transducer chip is flip-chip mounted onto a post-processed chip also comprising a chamber. The microphone system can be electrically connected to an external substrate by conventional techniques such as wire bonding.

Abstract: A method of manufacturing a transducer of the type having a diaphragm (11) with a predetermined tension. After the transducer has been manufactured with its basic structure the diaphragm is adjusted to have a predetermined tension, which is preferably low in order to obtain a high sensitivity. Two embodiments are disclosed. One embodiment includes heating the transducer to a temperature above the glass transition temperature of the material (12, 14) retaining the diaphragm. Another embodiment includes measuring the actual tension of the diaphragm, which can be used to calculate an adjustment of the thickness of the diaphragm resulting in the desired tension.