Design of microspeaker module considering added stiffness

Abstract

Mobile devices are becoming highly multi-functional due to the development of communication technology. The microspeaker mod- ule used in those devices, such as mobile phones or pads, is also playing important roles inside mobile devices. The conventional mi- crospeaker modules normally have two demerits including a non-standardized total shape for different types of devices and a size too large for miniaturization design. This paper reports a novel structure design of a microspeaker module considering the added stiffness to minimize the total dimensions without affecting the acoustic performance. At the same time, a standardized novel microspeaker design was applied to different types of mobile devices with sustained performance. The finite element method (FEM) was applied for electro- magnetic analysis and dynamic analysis. The respond surface method (RSM) was used for optimization. As a design result, the total volume was decreased by 51.8%. The simulation showed that compared to the conventional design, the novel design maintains the reso- nance frequency and sound pressure level (SPL) value. Prototypes were constructed and acoustic tests were conducted. The simulation results were verified experimentally. The results revealed the novel design to have a similar resonance frequency with conventional de- sign. In addition, the mean SPL value from 800 Hz to 5 kHz for the conventional and novel designs were maintained with 94.33 dB and 94.98 dB, respectively, that means novel design has maintained acoustic performance as conventional design.