Method of making a low stress cavity package for back side illuminated image sensor

A method of forming an image sensor package, comprising:

• providing an image sensor chip that includes a substrate with front and back opposing surfaces, a plurality of photo detectors formed at the front surface, and a plurality of contact pads formed at the front surface which are electrically coupled to the photo detectors;
• providing a crystalline handler having opposing first and second surfaces;
• attaching the image sensor chip substrate front surface to the crystalline handler second surface;
• forming a cavity into the first surface;
• forming a compliant dielectric material in the cavity;
• forming a plurality of electrical interconnects, each formed by:
• forming a hole with a first portion extending from the second surface to the cavity and a second portion extending through the compliant dielectric material, wherein the hole is aligned with one of the contact pads,
• forming a layer of insulation material along a sidewall of the first portion of the hole, and
• forming conductive material that extends through the first and second portions of the hole, wherein the conductive material is electrically coupled to the one contact pad.