Method of attaching a chip to a flexible substrate

An electronic circuit, comprising:

• an electronic component having bump terminations on a first surface thereof,
• a flexible substrate having a plurality of generally round holes therein arranged in correspondence with said bump terminations, wherein each of said holes is defined by a hole periphery of said substrate immediately about each hole, wherein each hole has a diameter d smaller than a largest diameter D of a corresponding bump termination;
• and
• an array of conductive circuit traces arranged on a second surface of said substrate, wherein each of said circuit traces terminates proximate one of the holes in said substrate;
• wherein each bump termination has a substantially bulbous profile having:
• a neck portion attached to said substrate and having a diameter d.sub.N, and
• an end portion distal from said substrate and having a diameter D,
• wherein D>d.sub.N >d;
• each bump termination being fixably inserted into its corresponding hole in said substrate so as to stretch its corresponding hole periphery and enlarge said corresponding hole, thereby providing a compressive gripping force exerted by each stretched hole periphery on its corresponding bump termination, so as to mechanically connect said electronic component with said substrate and to electrically connect each termination with a corresponding circuit trace.

An electronic circuit, comprising:

• an electronic component having bump terminations on a first surface thereof;
• a flexible substrate having a plurality of generally round holes therein arranged in correspondence with said bump terminations, wherein each of said holes is defined by a hole periphery of said substrate immediately about each hole, wherein each hole has a diameter d smaller than a largest diameter D of a corresponding bump termination;
• and
• an array of conductive circuit traces arranged on a second surface of said substrate, wherein each of said circuit traces terminates proximate one of the holes in said substrate;
• wherein each bump termination has a substantially bulbous profile having:
• a neck portion attached to said substrate and having a diameter d.sub.N, and
• an end portion distal form said substrate and having a diameter D,
• wherein D>d.sub.N >d;
• wherein said bump terminations have an average bump height and wherein said substrate has a thickness between 20% and 50% of the average bump height, inclusive;
• each bump termination being fixably inserted into its corresponding hole in said substrate so as to stretch its corresponding hole periphery and enlarge said corresponding hole, thereby providing a compressive gripping force exerted by each stretched hole periphery on its corresponding bump termination, so as to mechanically connect said electronic component with said substrate and to electrically connect each termination with a corresponding circuit trace.