MEMS optical acoustic sensors manufactured in laminates

Latest advancement in printed circuit board (PCB) technologies and discoveries of novel laminate materials has enabled a series of laminate MEMS devices to be designed, fabricated, and productized. To demonstrate the benefit in design and fabrication using the Laminate MEMS technology, we introduce embedded MEMS optical sensors fabricated directly within PCB layers. Free-standing polymeric waveguides translate acoustic signals into optical ones with varied frequency response, directionality and dynamic range. Fiber optics components such as optical transmission lines, mirrors and beam-shaping lens are integrated in the same multi-layer electrical packages. Standard multi-mode, multichannel optical fiber connectors are adopted to seamlessly transfer optical signals to a linear photo detector array. Besides being low-cost and easy to integrate, this inline waveguide sensor design is completely EMI free, ideal for in-situ monitoring of acoustic emission from microelectronics packaging processes.