Patent ID: 7276394

Claim:
A low temperature method for producing a substantially flat large area image sensor assembly, the method comprising the steps of: (a) providing a die attach substrate having a substantially planar surface; (b) providing a lead frame having a bonding surface and a plurality of leads extending there from; (c) adhering an imager die to the substantially planar surface of the die attach substrate with a low curing temperature first adhesive wherein step (c) further comprises the steps in any order: (c1) dispensing said first adhesive onto the die attach substrate in a desired pattern; (c2) placing said die attach substrate with first adhesive pattern into the substrate recess of a first plate of a die attach fixture; (c3) placing the imager die into the imager die recess of a second plate of the die attach fixture while applying vacuum through a vacuum port in said second plate; and wherein, after steps (c1) through (c3), step (c) further comprises in sequential order the steps of: (c4) bringing the second plate towards the first plate of the die attach fixture to provide an even force distribution over the entire imager surface; (c5) pressing the first and second plate at constant pressure for a period of time; and (c6) removing the pressure, the vacuum and the die attach substrate with adhered imager die for curing; and (d) adhering the die attach substrate with adhered imager die to a bonding surface of the lead frame with a low curing temperature second adhesive for producing an image sensor assembly.