Laser machining of high density two-dimensional ultrasound arrays

A three-year effort to produce a two-dimensional ultrasound array using laser micromachining methods is described. A new array architecture was developed to take advantage of the laser machining methods. Direct-write laser ablation using a tripled-YAG laser emitting a wavelength of 355 nm was used to drill vias, define electrode patterns and machine kerfs. A 24×24 (576 element), 5 MHz array with 300 μm spacing was produced and tested. An eight-layer laminate design flex circuit was produced in-house and used to connect the array