Removable layer manufacturing method

An electronic assembly manufactured by the method comprising:

• attaching an electronic die by a front surface of the die to a temporary substrate, wherein the die has a highly conductive coating and a sacrificial layer on a back surface of the die and electrical contacts on the front surface of the die;
• over-molding the sacrificial layer with a first material extending laterally over the temporary substrate;
• detaching the die and the first material from the temporary substrate;
• providing an interconnect layer over the first material and the die, having leads electrically coupled to the electrical contacts of the die;
• over-molding the interconnect layer with a second material;
• thinning the first material to expose the sacrificial layer but not to entirely remove the sacrificial layer, thus defining a surface of the first material that is planar with a surface of the sacrificial layer;
• removing the sacrificial layer so that the back surface of the die is recessed with respect to a surface of the first material, thus defining a recessed area at the back surface of the die;
• and
• providing conductors contacting the highly conductive coating on the back surface of the die and the leads of the interconnect layer, resulting in a conductor on the back surface of the die in the recessed area.

A method for forming an electrical assembly, comprising:

• providing an electronic die with electrical contacts on a front face and a sacrificial material on an opposed rear face;
• attaching the front face to a temporary substrate;
• coating the sacrificial material and the temporary substrate laterally outside the die with a first support material;
• removing the temporary substrate thereby exposing the front face of the die and a first face of the first support material;
• forming one or more interconnect layers over the front face of the die and the first face of the first support material, having leads electrically coupled to the electrical contacts on the front face of the die, wherein an outermost interconnect layer has an outer surface with outer contacts thereon;
• over-molding the outer surface and outer contacts of the outermost interconnect layer with a second support material;
• removing a portion of the first support material to expose the sacrificial layer and a second surface of the first support material laterally outside the electronic die;
• removing the sacrificial layer to expose the rear face of the die;
• etching vias in the second surface of the first support material laterally outside the electronic die, extending through the first support material to leads of the first interconnect layer;
• and
• filling the vias and coating the rear face of the die with a further conductor, wherein the further conductor provides electrical coupling to leads of a first interconnect layer and electrical and thermal contact with the rear face of the die.