Matching layer is a critical component that determines the performance of piezoelectric ultrasound transducer. For most piezoelectric materials, their acoustic impedances are significantly higher than human tissues and organs, so a tunable matching layer with a high acoustic impedance is required for optimizing the acoustic wave transmission. In this article, a high compression fabrication method is presented, with which the acoustic impedance of alumina-epoxy composite matching layer can be tuned from 6.50 to 9.47 MRayl by controlling the applied compression pressure and ratio of the components. The maximum acoustic impedance 9.47 MRayl can be achieved by compressing a mixture of 80% alumina weight ratio under a 62.4 MPa pressure. This enhancement mainly relies on the increased acoustic longitudinal velocity which enlarged the tolerance of high to ultra-high frequency transducer fabrication using quarter wavelength matching design. Furthermore, the attenuation of the matching layer developed by this method is only −10 dB/mm at 40 MHz. The very high acoustic impedance value and very low attenuation make this matching material superior than all reported matching materials, and therefore, can enhance the performance of the ultrasound transducers, especially for medical imaging applications.

匹配层是决定压电超声换能器性能的关键部件。对于大多数压电材料，其声阻抗明显高于人体组织器官，因此需要具有高声阻抗的可调匹配层来优化声波传输。在本文中，提出了一种高压缩制造方法，通过控制施加的压缩压力和组件的比例，可以将氧化铝-环氧树脂复合匹配层的声阻抗从 6.50 调整到 9.47 MRayl。通过在 62.4 MPa 压力下压缩 80% 氧化铝重量比的混合物可以实现最大声阻抗 9.47 MRayl。这种增强主要依赖于增加的声学纵向速度，这扩大了使用四分之一波长匹配设计的高频到超高频换能器制造的容差。此外，通过这种方法开发的匹配层的衰减在 40 MHz 时仅为 -10 dB/mm。非常高的声阻抗值和非常低的衰减使这种匹配材料优于所有报道的匹配材料，因此，可以增强超声换能器的性能，特别是对于医学成像应用。