School of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea.
Office of Nano Convergence Technology, National NanoFab Center, Daejeon 34141, Korea.
Sensors (Basel). 2022 Jul 25;22(15):5557. doi: 10.3390/s22155557.
An acoustic matching layer is an essential component of an ultrasound transducer to achieve maximum ultrasound transmission efficiency. Here, we develop a flexible printed circuit board (FPCB) with a composite structure consisting of multiple polyimide and copper layers and demonstrate it as a novel acoustic matching layer. With a flexible substrate and robust ACF bonding, the FPCB not only serves as an acoustic matching layer between piezoelectric elements and the surrounding medium but also as a ground for the electrical connection between the transducer array elements and the folded substrate. A 1D linear ultrasound transducer array with the FPCB matching layer exhibits larger output pressure, wider -3dB bandwidth, and higher ultrasound beam intensity compared to that of an ultrasound transducer array with the alumina/epoxy matching layer, which is one of the most commonly applied composite matching layers. The enhanced transmission performance verifies that the proposed FPCB is an excellent matching layer for 1D linear ultrasound transducer arrays.
声匹配层是超声换能器的重要组成部分，可实现最大的超声传输效率。在这里，我们开发了一种由多层聚酰亚胺和铜层组成的复合结构的柔性印刷电路板（FPCB），并将其用作新型声匹配层。FPCB 具有柔性基底和可靠的 ACF 键合，不仅可用作压电元件与周围介质之间的声匹配层，还可用作换能器阵列元件与折叠基底之间的电连接的接地层。与使用氧化铝/环氧匹配层的超声换能器阵列相比，具有 FPCB 匹配层的 1D 线性超声换能器阵列具有更大的输出压力、更宽的-3dB 带宽和更高的超声束强度。这种增强的传输性能验证了所提出的 FPCB 是 1D 线性超声换能器阵列的出色匹配层。
