Combined piezoelectric vibrator and preparation method thereof

Abstract

The invention discloses a combined piezoelectric vibrator and a preparation method thereof. The combined piezoelectric vibrator comprises a plurality of piezoelectric columns which are distributed in arrays. The piezoelectric columns are bonded into a combined body through polymers. The upper surface of the combined body is an inwards concave curved surface. The upper end surfaces of the piezoelectric columns are exposed out of the upper surface of the combined body. The lower end surfaces of the piezoelectric columns are exposed out of the lower surface of the combined body. Two layers of electrode materials are respectively plated on the upper surface and the lower surface. By adopting the scheme, since the upper surface which is used as a transmitting surface of the piezoelectric vibrator is inwards concave, the energy of sound waves can be concentrated in an area required to be detected, the sensitivity and the lateral resolution of an ultrasonic transducer can be improved, the electromechanical coupling factor is improved and the mechanical quality factor is effectively reduced. Besides, since the upper surface of the piezoelectric vibrator is inwards concave and focused, sound lens materials are not required to be additionally used, the structure of the ultrasonic transducer is simplified and the energy loss caused by a sound lens during sound wave transmission is reduced. 本发明公开了一种复合压电振子及其制备方法，该压电振子包括：呈阵列分布的多个压电柱，多个压电柱由聚合物粘结成一复合体，复合体的上表面为内凹的曲面，多个压电柱的上端面暴露于该上表面，该多个压电柱的下端面暴露于该复合体的下表面，该上表面及该下表面分别镀有一层电极材料。本发明的方案中，由于作为压电振子的发射面的上表面内凹，可将声波的能量集中在需要探测的区域，可提高超声换能器的灵敏度及横向分辨率，提升机电耦合系数，有效地降低了机械品质因数值。此外，该压电振子本身由于上表面内凹而聚焦，因此不需要额外使用声透镜材料，精简了超声换能器的结构和减少声透镜造成的声波传输过程中能量的损失。