Micromechanical piezoelectric micromachined ultrasonic transducer array package enhancement with integrated frontliners

Abstract

In order to improve the susceptibility of ultrasonic transducers to damage and the mismatch in acoustic impedance with test specimens, an impedance-matching layer is introduced between the transducer and the specimen. The impact of the matching layer on acoustic propagation of transducer was analyzed through acoustic field simulation. The performance of the improved transducer was experimentally evaluated by using a dedicated echo testing system for transducers. The matching layer was optimized by considering different materials. The results show that for non-metallic materials, only a layer of acoustic matching layer (organic silicone gel) can be added to achieve acoustic impedance matching and avoid wear. For metal materials, two acoustic matching layers (organic silicone gel and epoxy resin) need to be added to achieve acoustic impedance matching. The propagation efficiency of sound waves is increased by 30% as a result of this process.