Stretchable electronics fabrication method with strain redistribution layer

A method of forming a microelectronic device, comprising:

• attaching a semiconductor die to a carrier substrate that includes a plurality of conductive traces, wherein one or more die contacts on the semiconductor die are electrically coupled to the contact pad by the conductive traces;
• forming an encapsulation layer over the semiconductor die, and the carrier substrate;
• forming a first strain redistribution layer over a top surface of the encapsulation layer;
• removing the carrier substrate;
• and
• forming a second encapsulation layer below the semiconductor die.

A microelectronic device comprising:

• a semiconductor die having one or more die contacts that are each electrically coupled to a contact pad by a conductive trace, wherein the semiconductor die has a first elastic modulus;
• an encapsulation layer over the semiconductor die and the conductive trace, wherein the encapsulation layer has a second elastic modulus that is less than the first elastic modulus;
• and
• a first strain redistribution layer within the encapsulation layer, wherein the first strain redistribution layer has a footprint that covers the semiconductor die and a portion of the conductive traces, wherein the strain redistribution layer has a third elastic modulus that is less than the first elastic modulus and greater than the second elastic modulus, wherein the first elastic modulus is an order of magnitude greater than the third elastic modulus, and wherein the third elastic modulus is an order of magnitude grade than the second elastic modulus, and wherein the first strain redistribution layer includes one or more perforations, wherein the perforations proximate to an outer perimeter of the first strain redistribution layer are larger than the perforations proximate to a center of the first strain redistribution layer.