Rounded die configuration for stress minimization and enhanced thermo-mechanical reliability

A method of singulating a die from a wafer, comprising:

• providing a wafer having a multiplicity of dice defined therein;
• masking the wafer with a resist that includes a multiplicity of die definition islands, each die definition island overlying an associated die and having at least one rounded corner;
• and
• plasma etching the wafer to singulate the dice thereby defining a multiplicity of singulated dice, each having at least one rounded sidewall junction edge corner.

A semiconductor package comprising:

• a leadframe having a die attach pad and a plurality of contact leads, the die attach pad having a top surface, a bottom surface and recessed regions in the top surface of the die attach pad that define a plurality of pedestals supported by a web, there being gaps between adjacent pedestals;
• a die mounted on the die attach pad such that the die is supported by at least a plurality of the pedestals, wherein selected edge regions of the die are arranged to overlie recessed regions of the die attach pad, wherein the die is electrically connected to at least some of the contact leads, wherein the die has a top surface, a bottom surface and a plurality of sidewalls, wherein the intersection between each pair of adjacent sidewalls defines a sidewall junction edge corner and wherein each sidewall junction edge corner is substantially rounded to reduce stress accumulations at the corners of the die.
• an adhesive that secures the die to the die attach pad, wherein the adhesive is arranged to secure the die to the pedestals that support the die and to the web, wherein the thickness of the adhesive between the web of the die attach pad and the die is greater than the thickness of the adhesive between the die and top surfaces of the pedestals that support the die;
• and
• an encapsulant that encapsulates the die and at least a portion of the die attach pad.