Flip chip bonding method using electrically conductive polymer bumps

A method of forming an electrically conductive interconnection between a bond pad of a flip chip and a bond pad of a substrate comprising the steps of:

• a) selectively forming a first organic protective layer over a surface of the flip chip around the flip chip bond pad, leaving the flip chip bond pad exposed;
• b) forming a first electrically conductive polymerizable precursor layer on the flip chip bond pad;
• c) forming a second electrically conductive polymerizable precursor layer over the first electrically conductive polymerizable precursor layer, the second electrically conductive polymerizable precursor layer and the first layer together forming a bump;
• d) selectively forming a second organic protective layer over a surface of the substrate around the substrate bond pad, leaving the substrate bond pad exposed;
• e) forming an electrical interconnection between the bump and the substrate bond pad, thereby forming an electrical interconnection between the flip chip bond pad and the substrate bond pad.

A method of forming an electrically conductive interconnection between a bond pad of a flip chip and a bond pad of a substrate comprising the steps of:

• a) selectively forming a first organic protective layer over a surface of the flip chip around the flip chip bond pad, leaving the flip chip bond pad exposed;
• b) forming a first electrically conductive polymerizable precursor layer on the flip chip bond pad;
• c) drying the first electrically conductive polymerizable precursor layer;
• d) forming a second electrically conductive polymerizable precursor layer over the first electrically conductive polymerizable precursor layer to a level extending beyond the first organic protective layer;
• e) drying the second electrically conductive polymerizable precursor layer to form a bump on the flip chip;
• f) selectively forming a second organic protective layer over a surface of the substrate around the substrate bond pad to a level extending beyond the level of the substrate bond pad, leaving the substrate bond pad exposed;
• g) contacting the bump to the substrate bond pad;
• and
• h) while so contacted, polymerizing the bump to form an electrically conductive interconnection between the flip chip bond pad and the substrate bond pad.

A method of forming an electrically conductive interconnection between a bond pad of a flip chip and a bond pad of a substrate comprising the steps of:

• a) selectively forming a first organic protective layer over a surface of the flip chip around the flip chip bond pad, leaving the flip chip bond pad exposed;
• b) forming a first electrically conductive polymerizable precursor layer on the flip chip bond pad;
• c) polymerizing the first electrically conductive polymerizable precursor layer to form a first electrically conductive polymer layer;
• d) forming a second electrically conductive polymer layer on the first electrically conductive polymer layer to a level extending beyond the first organic protective layer;
• e) polymerizing the second electrically conductive polymerizable precursor layer to form a second electrically conductive polymer layer, the first electrically conductive polymer layer and the second electrically conductive polymer layer together forming an electrically conductive bump on the flip chip bond pad;
• f) selectively forming a second organic protective layer on a surface of the substrate to a level extending beyond the level of the substrate bond pad, leaving the substrate bond pad exposed;
• g) applying an electrically conductive adhesive to the substrate bond pad;
• and
• h) contacting the electrically conductive adhesive to the electrically conductive bump to form an electrically conductive interconnection between the flip chip bond pad and the substrate bond pad.