Packaging structures and packaging methods for ultrasound-on-chip devices

A method of manufacturing an ultrasound imaging device, the method comprising:

• forming a multi-layer hybrid interposer structure, comprising:
• forming a plurality of first openings through a substrate, the substrate comprising a heat spreading material;
• forming a first metal material within the plurality of first openings and on top and bottom surfaces of the substrate;
• patterning the first metal material on the top and bottom surfaces of the substrate;
• forming a dielectric layer over the patterned first metal material on the top and bottom surfaces of the substrate;
• forming a plurality of second openings within the dielectric layer to expose portions of the patterned first metal material on the top and bottom surfaces of the substrate;
• filling the plurality of second openings with a second metal material, in contact with the exposed portions of the patterned first metal material;
• forming a third metal material on the top and bottom surfaces of the substrate, wherein the third metal material is in contact with the second metal material and the dielectric layer;
• and
• patterning the third metal material;
• and
• forming a packaging structure for an ultrasound-on-chip device, comprising:
• attaching a multi-layer flex substrate to a carrier wafer;
• bonding a first side of an ultrasound-on-chip device to the multi-layer flex substrate;
• bonding a second side of the ultrasound-on-chip device to a first side of the multi-layer hybrid interposer structure;
• and
• removing the carrier wafer.