IEEE Trans Ultrason Ferroelectr Freq Control. 2014 Mar;61(3):547-56. doi: 10.1109/TUFFC.2014.2938.
An electrophoretic deposition (EPD) process with high deposition rate was used to fabricate a curved piezoelectric thick film devoted to high-frequency transducers for medical imaging. Niobium-doped lead zirconate titanate (PZTNb) powder was stabilized in ethanol to prepare a suspension with high zeta potential and low conductivity. A gold layer, pad-printed and fired on a curved porous PZT substrate, was used as the working electrode for the deposition of the PZTNb thick film. This substrate was chosen because it has the required properties (acoustic impedance and attenuation) to be used directly as a backing for the high-frequency transducer, leading to a simplified process for transducer assembly with this integrated structure. PZT-Nb thick films were also deposited by EPD on flat gold-coated alumina substrates as a reference. The thickness of the films was between 20 and 35 μm, and their electromechanical performance was comparable to standard PZT bulk ceramics with a thickness coupling factor of 48%. For the curved thick film, the thickness coupling factor was slightly lower. The corresponding integrated structure was used to fabricate a transducer with a center frequency of 40 MHz and an f-number of 2.8. It was integrated into a realtime ultrasound scanner and used to image human forearm skin; the resulting images showed, for the first time, the efficacy of the EPD process for these imaging applications.
采用电泳沉积（EPD）工艺以高沉积速率制备用于医学成像的高频换能器的弯曲压电厚膜。将掺铌锆钛酸铅（PZTNb）粉末稳定在乙醇中，以制备具有高 zeta 电位和低电导率的悬浮液。金层通过印刷和在弯曲多孔 PZT 衬底上烧制，用作沉积 PZTNb 厚膜的工作电极。选择这种衬底是因为它具有所需的特性（声阻抗和衰减），可直接用作高频换能器的背衬，从而简化了具有这种集成结构的换能器组件的工艺。还通过 EPD 将 PZT-Nb 厚膜沉积在平坦的镀金氧化铝衬底上作为参考。膜的厚度在 20 至 35μm 之间，其机电性能与厚度耦合系数为 48%的标准 PZT 块状陶瓷相当。对于弯曲的厚膜，厚度耦合系数略低。使用相应的集成结构制造了中心频率为 40MHz 和 f-number 为 2.8 的换能器。它集成到实时超声扫描仪中，用于对人体前臂皮肤进行成像；首次显示了 EPD 工艺在这些成像应用中的效果。
