US5393697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite bump structure and methods of fabrication
Assignee: Industrial Technology Research Institute
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Filing: 1994-05-06
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Granted: 1995-02-28
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Expires: 2014-05-06
Abstract
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.
Inventors
- 👤 Shyh-Ming Chang
- 👤 Yu-Chi Lee
- 👤 Hsiu-Mei Yu
- 👤 Li-Hui Yang
- 👤 Jwo-huei Jou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:26
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/01; H10W72/012; H10W72/20; H10W72/01231; H10W72/01251; H10W72/221; H10W72/222; H10W72/223; H10W72/231; H10W72/234; H10W72/241; H10W72/245; H10W72/251; H10W72/252; H10W72/253; H10W72/255; H10W72/90; H10W72/921; H10W72/923; H10W72/951; H10W72/952
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
107 words
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.
Claim 2
Independent Claim
107 words
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.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein said polymer is non photosensitive polyamic acid polyimide.
Claim 4
Dependent Claim
49 words
The method of claim 1, further comprising: forming a base metal layer on the integrated circuit element or substrate prior to forming said polymer layer; and etching said base metal not protected by said second photoresist mask, after etching said conductive metal, and before stripping said second photoresist mask.
Claim 5
Dependent Claim
11 words
The method of claim 3 wherein said base metal is aluminum.
Claim 6
Dependent Claim
28 words
The method of claim 1 wherein said conductive metal coating is a layer of chrome about 500 Angstroms thick and a layer of gold about 2000 Angstroms thick.
Claim 7
Dependent Claim
21 words
The method of claim 1 wherein said conductive metal coating includes an adhesion layer, a barrier layer, and a conductor layer.
Claim 8
Dependent Claim
74 words
The method of claim 1, further comprising: forming a third photoresist mask on said integrated circuit element or substrate, after the second photoresist mask has been stripped, covering the entire integrated circuit element or substrate surface except the area directly over the input/output pads; forming a layer of soldering metal on said third photoresist mask and said composite bumps; and stripping said third photoresist mask thereby leaving soldering metal only on the composite bumps.
Claim 9
Dependent Claim
15 words
The method of claim 7 wherein said soldering metal is 95% lead and 5% tin.
Claim 10
Independent Claim
103 words
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.
Claim 11
Independent Claim
103 words
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.
Claim 12
Dependent Claim
14 words
The method of claim 9 wherein said photosensitive polymer is photosensitive polyamic acid polyimide.
Claim 13
Dependent Claim
49 words
The method of claim 9, further comprising: forming a base metal layer on the integrated circuit element or substrate prior to forming said polymer layer; and etching said base metal not protected by said first photoresist mask, after etching said conductive metal, and before stripping said first photoresist mask.
Claim 14
Dependent Claim
11 words
The method of claim 11 wherein said base metal is aluminum.
Claim 15
Dependent Claim
28 words
The method of claim 9 wherein said conductive metal coating is a layer of chrome about 500 Angstroms thick and a layer of gold about 2000 Angstroms thick.
Claim 16
Dependent Claim
21 words
The method of claim 9 wherein said conductive metal coating includes an adhesion layer, a barrier layer, and a conductor layer.
Claim 17
Dependent Claim
75 words
The method of claim 9, further comprising: forming a second photoresist mask on said integrated circuit element or substrate, after the first photoresist mask has been stripped, covering the entire integrated circuit element or substrate surface except the area directly over the input/output pads; forming a layer of soldering metal on said second photoresist mask and said composite bumps; and stripping said second photoresist mask thereby leaving only the soldering metal on the composite bumps.
Claim 18
Dependent Claim
15 words
The method of claim 15 wherein said soldering metal is 95% lead and 5% tin.
Claim 19
Independent Claim
106 words
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.
Claim 20
Independent Claim
106 words
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.
Claim 21
Dependent Claim
70 words
The method of claim 17 wherein said vapor deposition polymerization comprises: providing a vacuum of about 3.75×10 -5 Torr; spraying 4,4 Oxy-Dianiline onto said integrated circuit element or substrate; heating said integrated circuit element or substrate to between about 80° C. and 160° C.; spraying pyromellitic dianhydride onto said integrated circuit element or substrate; and heating said integrated circuit element or substrate to between about 130° C. and 180° C.
Claim 22
Dependent Claim
28 words
The method of claim 17 wherein said conductive metal coating is a layer of chrome about 500 Angstroms thick and a layer of gold about 2000 Angstroms thick.
Claim 23
Dependent Claim
21 words
The method of claim 17 wherein said conductive metal coating includes an adhesion layer, a barrier layer, and a conductor layer.
Claim 24
Dependent Claim
77 words
The method of claim 17, further comprising: forming a second photoresist mask on said integrated circuit element or substrate by lithography, after the first photoresist mask has been stripped, covering the entire integrated circuit element or substrate surface except the area directly over the input/output pads; forming a layer of soldering metal on said second photoresist mask and said composite bumps; and stripping said second photoresist mask thereby leaving only the soldering metal on the composite bumps.
Claim 25
Dependent Claim
15 words
The method of claim 21 wherein said soldering metal is 95% lead and 5% tin.
References Cited (Backward Citations)
US3401126A
Cited
US3809625A
Cited
JPS60121740A
Cited
US5134460A
Cited
US4749120A
Cited
US5223454A
Cited
US4963002A
Cited
US4916523A
Cited
US5138424A
Cited
US5208186A
Cited
US5071787A
Cited
US5155576A
Cited
US5290732A
Cited
JPH05182972A
Cited
US5284797A
Cited
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| 3.5 Years (Year 4) | 1998-02-27 | 1998-08-29 | 1999-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-02-27 | 2002-08-29 | 2003-02-28 | $3760.00 | Window Closed / Lapsed |
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