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US4931323A Expired / Lapsed US ⏱️ 0.0 years remaining

Thick film copper conductor patterning by laser

Assignee: Texas Instruments Inc
•
Filing: 1988-10-06
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Granted: 1990-06-05
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Expires: 2008-10-06
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Abstract

Abstract This invention discloses a method of forming a conductor on a copper conductor on a semiconductor interconnection surface. A paste of copper material is formed over at least a portion of the semiconductor interconnection surface. A laser beam is directed against the paste. The laser beam is moved along the paste in accordance with a pattern to define the conductor. The laser beam fires and sinters the paste to form the conductor. The remaining paste which remains unfired is removed. The surface and the fired paste is then maintained in an inert atmosphere while heated to a sufficient temperature to provide a high quality copper conductor on the surface.

Inventors

  • 👤 James Manitt
  • 👤 Scott Hull

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 12:52
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/01; H10W70/05; H10W70/098; H05; H05K; H05K3/00; H05K3/10; H05K3/105; H05K1/00; H05K1/02; H05K1/09; H05K1/092; H05K2203/00; H05K2203/07; H05K2203/0779; H05K2203/0783; H05K2203/08; H05K2203/086; H05K2203/10; H05K2203/107; H05K3/12; H05K3/1283; H05K3/22; H05K3/26

Claims Analysis

Total Claims: 23
Claim 1
Independent Claim 127 words
A method of forming an electrical conductor on a device surface comprising the steps of: (a) providing an unfired electrically conductive material; forming a layer of said unfired electrically conductive material over the device surface; (b) moving a beam of coherent radiant energy along a predetermined path on said layer of unfired electrically conductive material to fire the portions of said layer along said predetermined path to define the configuration of said electrical conductor; (c) removing the remainder of said electrically conductive material which remains unfired; and (d) applying sufficient heat to said surface and said fired electrically conductive material in an inert atmosphere to complete the formation of said electrical conductor and provide adherence of said electrical conductor to said device surface along said predetermined path.
Claim 2
Independent Claim 127 words
A method of forming an electrical conductor on a device surface comprising the steps of: (a) providing an unfired electrically conductive material; forming a layer of said unfired electrically conductive material over the device surface; (b) moving a beam of coherent radiant energy along a predetermined path on said layer of unfired electrically conductive material to fire the portions of said layer along said predetermined path to define the configuration of said electrical conductor; (c) removing the remainder of said electrically conductive material which remains unfired; and (d) applying sufficient heat to said surface and said fired electrically conductive material in an inert atmosphere to complete the formation of said electrical conductor and provide adherence of said electrical conductor to said device surface along said predetermined path.
Claim 3
Dependent Claim 16 words
The method of claim 1, wherein said beam of coherent radiant energy comprises a laser beam.
Claim 4
Dependent Claim 25 words
The method of claim 1, wherein said step of removing comprises washing said conductive material with liquid which tends to dissolve said unfired conductive material.
Claim 5
Dependent Claim 18 words
The method of claim 1, wherein said applied heat is at a temperature of about 900 degrees C.
Claim 6
Dependent Claim 16 words
The method of claim 1, wherein said heat is applied in an inert atmosphere containing nitrogen.
Claim 7
Dependent Claim 25 words
The method of claim 1, wherein said unfired electrically conductive material comprises copper paste formed of copper particles, a ceramic base and an organic binder.
Claim 8
Dependent Claim 18 words
The method of claim 6, wherein said applied heat is at a temperature of about 900 degrees C.
Claim 9
Dependent Claim 14 words
The method of claim 6, wherein said device surface is formed of ceramic material.
Claim 10
Dependent Claim 18 words
The method of claim 8, wherein said applied heat is at a temperature of about 900 degrees C.
Claim 11
Independent Claim 153 words
A method of forming a copper electrical conductor on an interconnection surface suitable for connection to a semiconductor device comprising the steps of: (a) providing a paste of copper containing material; applying said paste of copper containing material over at least a portion of said interconnection surface; (b) providing a laser beam; (c) moving said laser beam along said paste in accordance with a predetermined pattern to define said electrical conductor along said pattern on said surface by said laser beam firing said paste along said pattern to form said conductor; (d) removing the remaining paste from said surface which remains unfired; (e) placing said surface and the remaining fired paste thereon in an inert atmosphere; and (f) applying heat to said remaining fired paste and said surface sufficient to provide a high quality copper conductor on the interconnection surface and provide adherence of said copper conductor to said surface along said pattern.
Claim 12
Independent Claim 153 words
A method of forming a copper electrical conductor on an interconnection surface suitable for connection to a semiconductor device comprising the steps of: (a) providing a paste of copper containing material; applying said paste of copper containing material over at least a portion of said interconnection surface; (b) providing a laser beam; (c) moving said laser beam along said paste in accordance with a predetermined pattern to define said electrical conductor along said pattern on said surface by said laser beam firing said paste along said pattern to form said conductor; (d) removing the remaining paste from said surface which remains unfired; (e) placing said surface and the remaining fired paste thereon in an inert atmosphere; and (f) applying heat to said remaining fired paste and said surface sufficient to provide a high quality copper conductor on the interconnection surface and provide adherence of said copper conductor to said surface along said pattern.
Claim 13
Dependent Claim 25 words
The method of claim 10, wherein said step of removing comprises washing said conductive material with liquid which tends to dissolve said unfired conductive material.
Claim 14
Dependent Claim 16 words
The method of claim 10, wherein said heat is applied in an inert atmosphere containing nitrogen.
Claim 15
Dependent Claim 13 words
The method of claim 10, wherein said surface is formed of ceramic material.
Claim 16
Dependent Claim 21 words
The method of claim 10, wherein said paste of copper material comprises copper particles, a ceramic base and an organic binder.
Claim 17
Dependent Claim 18 words
The method of claim 10, wherein said applied heat is at a temperature of about 900 degrees C.
Claim 18
Dependent Claim 21 words
The method of claim 15, wherein said paste of copper material comprises copper particles, a ceramic base and an organic binder.
Claim 19
Dependent Claim 13 words
The method of claim 15, wherein said surface is formed of ceramic material.
Claim 20
Dependent Claim 21 words
The method of claim 17, wherein said paste of copper material comprises copper particles, a ceramic base and an organic binder.
Claim 21
Independent Claim 165 words
A method of forming a copper electrical conductor on an interconnection surface suitable for connection to a semiconductor device comprising the steps of: (a) providing a paste of copper particles, a ceramic base and an organic binder; (b) providing a ceramic interconnection surface; (c) applying said paste over at least a portion of said interconnection surface; (d) providing a laser beam; (e) forming an electrical conductor along a predetermined pattern on said paste by moving said laser beam along said paste in accordance with said predetermined pattern to fire said paste along said pattern; (f) removing the remaining paste from said surface which remains unfired; (g) placing said surface and the remaining fired paste thereon in an inert atmosphere; and (h) causing said conductor to adhere to said surface by applying heat to said remaining fired paste and said surface sufficient to provide a high quality copper conductor on the interconnection surface and provide adherence of said copper conductor to said surface along said pattern.
Claim 22
Independent Claim 165 words
A method of forming a copper electrical conductor on an interconnection surface suitable for connection to a semiconductor device comprising the steps of: (a) providing a paste of copper particles, a ceramic base and an organic binder; (b) providing a ceramic interconnection surface; (c) applying said paste over at least a portion of said interconnection surface; (d) providing a laser beam; (e) forming an electrical conductor along a predetermined pattern on said paste by moving said laser beam along said paste in accordance with said predetermined pattern to fire said paste along said pattern; (f) removing the remaining paste from said surface which remains unfired; (g) placing said surface and the remaining fired paste thereon in an inert atmosphere; and (h) causing said conductor to adhere to said surface by applying heat to said remaining fired paste and said surface sufficient to provide a high quality copper conductor on the interconnection surface and provide adherence of said copper conductor to said surface along said pattern.
Claim 23
Dependent Claim 18 words
The method of claim 19, wherein said applied heat is at a temperature of about 900 degrees C.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-06-04 1993-12-04 1994-06-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-06-04 1997-12-04 1998-06-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-06-04 2001-12-04 2002-06-05 $7700.00 Window Closed / Lapsed

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