Bumping process and bump structure
AssigneeElan Microelectronics Corporation
InventorsChun-Ping Hu, Cheng-Chung Chen, Chien-Wen Tsi, Yu-Ching Lee
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Abstract
A bumping process comprises forming a passivation layer having a planarized surface covering a pad on a substrate, forming a hole penetrating through the passivation layer to expose a contact surface of the pad, and forming a bump on the contact surface and planarized surface. The planarized surface will provide a larger effective area for pressing, thereby minimizing the pad, enhancing the mechanical strength at the peripheral of the pad, providing more selection flexibility for anisotropic conductive film, reducing the possibilities of short circuit and current leakage within the bump gap, and increasing the yield of the pressing process and the conductive quality of the bump.
Claims36
A bumping process for forming a bump electrically coupled to a pad on a substrate, the process comprising the steps of:
- forming a passivation layer having a planarized surface for covering the pad;
- etching the passivation layer for forming a hole penetrating through the passivation layer to expose a contact surface of the pad;
- and
- forming the bump on the contact surface and planarized surface.
A bump structure for electrically coupling to a pad on a substrate, the bump structure comprising:
- a passivation layer having a planarized surface thereon for covering a portion of the pad;
- a contact surface on the pad;
- and
- a bump contacting the contact surface and planarized surface.
A bump pressing structure for electrically coupling a pad on a first substrate to a wire on a second substrate, the bump pressing structure comprising:
- a passivation layer having a planarized surface for covering a portion of the pad;
- a bump contacting a contact surface of the pad and the planarized surface, the bump having a planarized surface facing the planarized surface of the passivation layer;
- and
- a plurality of conductive particles compressed between the planarized surface of the bump and the wire.
Dependencies are inferred from the claim text.