Composite bump structure and methods of fabrication
AssigneeIndustrial Technology Research Institute
InventorsShyh-Ming Chang, Yu-Chi Lee, Hsiu-Mei Yu, Li-Hui Yang, Jwo-huei Jou
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Abstract
A composite bump structure and methods of forming the composite bump structure. The composite bump structure comprises a polymer body of relatively low Young's Modulus compared to metals covered by a conductive metal coating formed at the input/output pads of an integrated circuit element or substrate. The composite bump is formed using material deposition, lithography, and etching techniques. A layer of soldering metal can be formed on the composite bumps if this is desired for subsequent processing.
Claims22
A method of forming composite bumps, comprising:
- providing an integrated circuit element or substrate with input/output pads;
- forming a polymer layer on the surface of said integrated circuit element or substrate;
- forming a first photoresist mask on said polymer layer directly over said input/output pads;
- etching said polymer not protected by said first photoresist mask;
- stripping said first photoresist mask;
- forming a conductive metal layer over the surface of said integrated circuit element or substrate;
- forming a second photoresist mask on said conductive metal layer directly over said input/output pads;
- etching said conductive metal not protected by said second photoresist mask;
- and
- stripping said second photoresist mask.
A method of forming composite bumps, comprising:
- providing an integrated circuit element or a substrate with input/output pads;
- forming a layer of photosensitive polymer on the surface of said integrated circuit element or substrate;
- exposing and developing a pattern on said photosensitive polymer so as to leave photosensitive polymer directly over said input/output pads only;
- forming a conductive metal layer over the surface of said integrated circuit element or substrate;
- forming a first photoresist mask on said conductive metal layer directly over said input/output pads;
- etching said conductive metal layer not protected by said first photoresist mask;
- and
- stripping said first photoresist mask.
A method of forming composite bumps, comprising:
- providing an integrated circuit element or substrate with input/output pads;
- forming a first photoresist mask by lithography over said integrated circuit element or substrate surface except those areas directly over said input/output pads;
- forming a layer of non photosensitive polymer over the surface of said integrated circuit element or substrate using vapor deposition polymerization;
- forming a conductive metal layer over said integrated circuit element or substrate;
- and
- removing said first photoresist mask thereby removing said non photosensitive polymer and said conductive metal over said photoresist mask, leaving said non photosensitive polymer and said conductive metal over said input/output pads.
Dependencies are inferred from the claim text.