US5387495A
Expired / Lapsed
US
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Sequential multilayer process for using fluorinated hydrocarbons as a dielectric
Assignee: Hewlett Packard Development Co LP
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Filing: 1992-04-06
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Granted: 1995-02-07
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Expires: 2012-04-06
Abstract
Abstract A method of forming a multilayer circuit board is disclosed which includes a build-up process in which, beginning with a solidified layer of the dielectric disposed upon a substrate, alternate layers of conducting metal and dielectric are sequentially deposited. Each layer of conducting metal lines is defined using photoresist and a photolithographic technique. After the lines are deposited, the photoresist is removed and a second layer of photoresist defines the conductive posts which function as through holes between metal layers. After each layer of conductive line and posts is formed, and the photoresist is removed, the dielectric is flowed into place and solidified to insulate adjacent metal lines and posts. The process may be repeated as many times as necessary to build up layers of conducting metal and dielectric, and form the completed multilayer wiring board.
Inventors
- 👤 James C. K. Lee
- 👤 Arshad Ahmad
- 👤 Chune Lee
- 👤 Myrna E. Castro
- 👤 Francisca Tung
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:32
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/46; H05K3/4644; H05K3/4647; G; G03; G03F; G03F7/00; G03F7/0035; H10; H10W; H10W70/00; H10W70/01; H10W70/05; H10W70/60; H10W70/67; H10W70/69; H05K1/00; H05K1/02; H05K1/03; H05K1/05; H05K1/056; H05K2201/00; H05K2201/01; H05K2201/0137; H05K2201/015; H05K2203/00; H05K2203/07; H05K2203/0703; H05K2203/0733; H05K3/10; H05K3/108; H05K3/22; H05K3/24; H05K3/243
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
169 words
A method of forming a multilayered board interconnect structure on a substrate, said method including the steps of: coating a bop surface of said substrate with an insulating layer of tetra-fluoroethylene, depositing a seed layer of highly conductive material over said insulating layer, depositing a first layer of one or more conductive lines parallel to said top surface of said substrate, said layer of tetra-fluoroethylene insulating said one or more conductive lines from said substrate, depositing a patterned layer of electrically conductive posts extending perpendicularly above said substrate, said posts being located to overlie selected locations on said one or more conductive lines, removing the portions of said seed layer which are not covered by said one or more conductive lines and said posts, and depositing a layer of liquid consisting essentially of fluorinated hydrocarbon having a dielectric constant in the range 2.0 to 2.1 around said posts to provide isolation between said posts, whereby said multilayered board may be formed without lamination of successive layers or drilling holes.
Claim 2
Independent Claim
169 words
A method of forming a multilayered board interconnect structure on a substrate, said method including the steps of: coating a bop surface of said substrate with an insulating layer of tetra-fluoroethylene, depositing a seed layer of highly conductive material over said insulating layer, depositing a first layer of one or more conductive lines parallel to said top surface of said substrate, said layer of tetra-fluoroethylene insulating said one or more conductive lines from said substrate, depositing a patterned layer of electrically conductive posts extending perpendicularly above said substrate, said posts being located to overlie selected locations on said one or more conductive lines, removing the portions of said seed layer which are not covered by said one or more conductive lines and said posts, and depositing a layer of liquid consisting essentially of fluorinated hydrocarbon having a dielectric constant in the range 2.0 to 2.1 around said posts to provide isolation between said posts, whereby said multilayered board may be formed without lamination of successive layers or drilling holes.
Claim 3
Dependent Claim
50 words
A method as claimed in claim 1 including the steps of: prior to said step of depositing a first layer of one or more conductive lines, applying, exposing and developing a layer of photoresist over said substrate to establish the locations and patterns of said one or more conductive lines.
Claim 4
Dependent Claim
59 words
A method as claimed in claim 1 wherein: said step of depositing a first layer of one or more conductive lines includes forming a first patterned layer of photoresist over said seed layer, laying down said one or more conductive lines in openings defined by said first patterned layer of photoresist, and removing said first patterned layer of photoresist.
Claim 5
Dependent Claim
90 words
A method as claimed in claim 3 including the steps of: after removing said first patterned layer of photoresist, forming a second layer of photoresist having openings for said copper posts aligned with selected portions of said one or more conductive lines, and after said step of depositing a patterned layer of copper posts, removing said second layer of photoresist and said seed layer, and then covering said copper posts and said one or more conductive lines with a second layer of flowable tetra-fluoroethylene to insulate adjacent posts and lines.
Claim 6
Dependent Claim
40 words
A method as claimed in claim 4 including the step of: planarizing said second layer of tetra-fluoroethylene to be flush with the top of said copper posts so that further layers of conductive lines and copper posts may be deposited.
Claim 7
Dependent Claim
34 words
A method as claimed in claim 5 wherein: said second layer of tetra-fluoroethylene is originally deposited to a greater thickness than the height of said copper posts, whereafter said planarizing step is carried out.
Claim 8
Dependent Claim
69 words
A method as claimed in claim 6 including depositing additional layers of conductive lines and copper posts by repeating the steps of forming a first layer of photoresist, depositing a layer of one or more conductive lines, removing said first layer of photoresist, forming a second layer of photoresist, depositing a patterned layer of copper posts, removing said second layer of photoresist, and depositing a layer of flowable tetra-fluoroethylene.
Claim 9
Dependent Claim
33 words
A method as claimed in claim 4 including the step of: prior to said step of removing said second layer of photoresist, depositing a flash of chromium or nickel atop said copper posts.
Claim 10
Dependent Claim
34 words
A method as claimed in claim 3 including the step of: prior to removing said first patterned layer of photoresist, depositing a flash of chromium or nickel atop said one or more conductive lines.
Claim 11
Dependent Claim
12 words
The method of claim 1, wherein said electrically conductive posts are copper.
Claim 12
Independent Claim
197 words
A method of making a multilayered printed wiring board pattern on a planar substrate, said multilayered printed wiring board pattern including a pattern of electrically conductive horizontal buried lines running parallel to said substrate and electrically conductive vertical posts perpendicular to said substrate, said method including the steps of: coating the surface of said substrate with an insulating layer of tetra-fluoroethylene, depositing a seed layer of highly conductive material over said insulating layer, depositing a first layer of one or more conductive lines parallel to a top surface of said substrate to form said buried horizontal lines, said layer of tetra-fluoroethylene insulating said one or more conductive lines from said substrate, patterning layers of photoresist having a dielectric constant in the range 2.0 to 2.1 to define the location and direction of said horizontal lines and said vertical posts, said posts being located to overlie selected locations on said one or more conductive lines, forming said lines and said posts, and applying liquid consisting essentially of fluorinated hydrocarbon around said lines and said posts to provide isolation between said lines and said posts, whereby a multilayered board is formed without lamination of successive layers or drilling holes.
Claim 13
Independent Claim
197 words
A method of making a multilayered printed wiring board pattern on a planar substrate, said multilayered printed wiring board pattern including a pattern of electrically conductive horizontal buried lines running parallel to said substrate and electrically conductive vertical posts perpendicular to said substrate, said method including the steps of: coating the surface of said substrate with an insulating layer of tetra-fluoroethylene, depositing a seed layer of highly conductive material over said insulating layer, depositing a first layer of one or more conductive lines parallel to a top surface of said substrate to form said buried horizontal lines, said layer of tetra-fluoroethylene insulating said one or more conductive lines from said substrate, patterning layers of photoresist having a dielectric constant in the range 2.0 to 2.1 to define the location and direction of said horizontal lines and said vertical posts, said posts being located to overlie selected locations on said one or more conductive lines, forming said lines and said posts, and applying liquid consisting essentially of fluorinated hydrocarbon around said lines and said posts to provide isolation between said lines and said posts, whereby a multilayered board is formed without lamination of successive layers or drilling holes.
Claim 14
Dependent Claim
50 words
A method as claimed in claim 13 including the steps of: prior to said step of depositing a first layer of one or more conductive lines, applying, exposing and developing a layer of photoresist over said substrate to establish the locations and patterns of said one or more conductive lines.
Claim 15
Dependent Claim
48 words
A method as claimed in claim 11 wherein: said step of forming said lines includes forming a first patterned layer of photoresist over said seed layer, laying down said lines in openings defined by said first patterned layer of photoresist, and removing said first patterned layer of photoresist.
Claim 16
Dependent Claim
76 words
A method as claimed in claim 13 including the steps of: after removing said first patterned layer of photoresist, forming a second layer of photoresist having openings for said posts aligned with selected portions of said lines, and, after said step of forming said posts, removing said second layer of photoresist and said seed layer, and then covering said posts and said lines with a second layer of flowable tetra-fluoroethylene to insulate adjacent posts and lines.
Claim 17
Dependent Claim
41 words
A method as claimed in claim 14 including the steps of: prior to said step of forming said lines, applying, exposing and developing said first patterned layer of photoresist over said substrate to establish the locations and patterns of said lines.
Claim 18
Dependent Claim
37 words
A method as claimed in claim 15 including the step of: planarizing said second layer of tetra-fluoroethylene to be flush with the top of said posts so that further layers of lines and posts may be formed.
Claim 19
Dependent Claim
38 words
A method as claimed in claim 15 including the step of: prior to said step of removing said second layer of photoresist, depositing a flash of chromium or nickel atop said posts, said posts being formed of copper.
Claim 20
Dependent Claim
57 words
A method as claimed in claim 16 including depositing additional layers of lines and posts by repeating the steps of forming a first layer of photoresist, forming said lines, removing said first layer of photoresist, forming a second layer of photoresist, forming said posts, removing said second layer of photoresist, and depositing a layer of flowable tetra-fluoroethylene.
Claim 21
Dependent Claim
30 words
A method as claimed in claim 13 including the step of: prior to removing said first patterned layer of photoresist, depositing a flash of chromium or nickel atop said lines.
Claim 22
Dependent Claim
14 words
The method of claim 11, wherein said electrically conductive lines and posts are copper.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-02-06 | 1998-08-08 | 1999-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-02-06 | 2002-08-08 | 2003-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-02-06 | 2006-08-08 | 2007-02-07 | $7700.00 | Window Closed / Lapsed |