High Frequency 1.75D array using a 3D printed pitch-changing interposer backing

High frequency arrays (>10 MHz) have potential utility in clinical settings for ophthalmology, breast cancer, and skin cancer diagnosis, and have been used extensively for small animal imaging and would benefit from the use of 1.75D electronic focus in elevation to improve contrast resolution for cyst differentiation in cancer detection. Here we report a 1.75D array that utilizes a novel high frequency pitch-changing interposer backing that maps from a 70 μm×150 μm transducer element grid to a 150 μm×150 μm ASIC assembly grid to facilitate access to the 2D array of elements. A 1.75D array of PIN-PMN-PT material with 2 matching layers was fabricated on top of the interposer. The completed array had a grid of 10×8 elements with a measured center frequency of 16 MHz. The next step is assembly to an ASIC and then interface to a high frequency ultrasound system for imaging.