Patent EP0171741A2 successfully refreshed from Google Patents.
US5137751A
Expired / Lapsed
US
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Process for making thick multilayers of polyimide
Assignee: Texas A&M University System
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Filing: 1990-11-13
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Granted: 1992-08-11
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Expires: 2010-11-13
Abstract
Abstract A polyimide layer having a thickness greater than about 5 microns is formed on a substrate by coating a substrate with a solution of polymer and a solvent of the formula <IMAGE> wherein R1 and R2 are independently a hydrogen, a C1 to C6 alkyl moiety, or a <IMAGE> R5 is a C1 to C6 alkyl moiety; and R3 and R4 are independently hydrogen or a C1 to C6 alkyl moiety, and curing the resulting coated substrate.
Inventors
- 👤 Marvin J. Burgess
- 👤 Douglas E. Fjare
- 👤 Herbert J. Neuhaus
- 👤 Robert T. Roginski
- 👤 David A. Wargowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:44
CPC Classifications
B; B32; B32B; B32B27/00; C; C08; C08J; C08J3/00; C08J3/02; C08J3/09; C08J3/091; C08J3/095; B32B27/34; C08L; C08L79/00; C08L79/04; C08L79/08; C09; C09D; C09D179/00; C09D179/04; C09D179/08; G; G03; G03F; G03F7/00; G03F7/004; G03F7/038; G03F7/0387; C08J2379/00; C08J2379/04; C08J2379/08; H; H05; H05K; H05K3/00; H05K3/46; H05K3/4644; H05K3/4673; H05K3/4676
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
123 words
A method of coating a substrate which comprises: (a) applying a first layer of polyamic acid to the substrate; (b) partially imidizing the first layer of polyamic acid to provide a first polyimide layer; (c) applying a layer of polyamic acid over the first layer of polyimide wherein the polyamic acid is in a solvent of the formula ##STR8## wherein R 1 and R 2 are independently a hydrogen, a C 1 to C 6 alkyl moiety, or a ##STR9## R 5 is a C 1 to C 6 alkyl moiety; and R 3 and R 4 are independently hydrogen or a C 1 to C 6 alkyl moiety; and n is from 1 to 4 ; and (d) imidizing the polyamic acid.
Claim 2
Independent Claim
123 words
A method of coating a substrate which comprises: (a) applying a first layer of polyamic acid to the substrate; (b) partially imidizing the first layer of polyamic acid to provide a first polyimide layer; (c) applying a layer of polyamic acid over the first layer of polyimide wherein the polyamic acid is in a solvent of the formula ##STR8## wherein R 1 and R 2 are independently a hydrogen, a C 1 to C 6 alkyl moiety, or a ##STR9## R 5 is a C 1 to C 6 alkyl moiety; and R 3 and R 4 are independently hydrogen or a C 1 to C 6 alkyl moiety; and n is from 1 to 4 ; and (d) imidizing the polyamic acid.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein the solvent comprises a lower alkyl ether alcohol.
Claim 4
Dependent Claim
10 words
The method of claim 2 wherein the solvent comprises 2-(2-ethoxyethoxy)ethanol.
Claim 5
Dependent Claim
11 words
The method of claim 1 wherein the solvent comprises an ether.
Claim 6
Dependent Claim
11 words
The method of claim 4 wherein the solvent comprises 2-methoxyethyl ether.
Claim 7
Dependent Claim
12 words
The method of claim 1 wherein the polyimide comprises a fluorinated polymer.
Claim 8
Dependent Claim
21 words
The method of claim 6 wherein the fluorinated polymer comprises the reaction product of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride and at least one diamine.
Claim 9
Dependent Claim
21 words
The method of claim 1 wherein steps (a) to (d) are repeated to provide successive layers of polyimide on the substrate.
Claim 10
Independent Claim
137 words
A method of preventing cracking in an underlying polyimide layer on a substrate when additional layers of polyamic acid are applied to the underlying polyimide layer which comprises: (a) applying a first layer of polyamic acid to the substrate; (b) partially imidizing the first layer of polyamic acid to provide a first polyimide layer; and (c) applying a layer of polyamic acid over the first layer of polyimide wherein the polyamic acid is in a solvent of the formula ##STR10## wherein R 1 and R 2 are independently a hydrogen, a C 1 to C 6 alkyl moiety, or a ##STR11## R 5 is a C 1 to C 6 alkyl moiety; and R 3 and R 4 are independently hydrogen or a C 1 to C 6 alkyl moiety; and n is from 1 to 4.
Claim 11
Independent Claim
137 words
A method of preventing cracking in an underlying polyimide layer on a substrate when additional layers of polyamic acid are applied to the underlying polyimide layer which comprises: (a) applying a first layer of polyamic acid to the substrate; (b) partially imidizing the first layer of polyamic acid to provide a first polyimide layer; and (c) applying a layer of polyamic acid over the first layer of polyimide wherein the polyamic acid is in a solvent of the formula ##STR10## wherein R 1 and R 2 are independently a hydrogen, a C 1 to C 6 alkyl moiety, or a ##STR11## R 5 is a C 1 to C 6 alkyl moiety; and R 3 and R 4 are independently hydrogen or a C 1 to C 6 alkyl moiety; and n is from 1 to 4.
Claim 12
Dependent Claim
11 words
The method of claim 9 wherein n is at least 2.
Claim 13
Dependent Claim
14 words
The method of claim 9 wherein the solvent comprises a lower alkyl ether alcohol.
Claim 14
Dependent Claim
10 words
The method of claim 11 wherein the solvent comprises 2-(2-ethoxyethoxy)ethanol.
Claim 15
Dependent Claim
11 words
The method of claim 9 wherein the solvent comprises an ether.
Claim 16
Dependent Claim
11 words
The method of claim 13 wherein the solvent comprises 2-methoxyethyl ether.
Claim 17
Dependent Claim
13 words
The method of claim 9 wherein the polyamic acid comprises a fluorinated polymer.
Claim 18
Dependent Claim
21 words
The method of claim 15 wherein the fluorinated polymer comprises the reaction product of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride and at least one diamine.
Claim 19
Dependent Claim
21 words
The method of claim 9 wherein steps (a) to (c) are repeated to provide successive layers of polyimide on the substrate.
Claim 20
Independent Claim
129 words
A method of forming multiple layers of fluorine-containing polyimide on a substrate which comprises: (a) applying a first layer of fluorine-containing polyamic acid to the substrate; (b) partially imidizing the first layer of polyamic acid to provide a first polyimide layer; (c) applying a layer of polyamic acid over the first layer of polyimide wherein the polyamic acid is in a solvent of the formula ##STR12## wherein R 1 and R 2 are independently a hydrogen, a C 1 to C 6 alkyl moiety, or a ##STR13## R 5 is a C 1 to C 6 alkyl moiety; and R 3 and R 4 are independently hydrogen or a C 1 to C 6 alkyl moiety; and n is from 1 to 4; and (d) imidizing the polyamic acid.
Claim 21
Independent Claim
129 words
A method of forming multiple layers of fluorine-containing polyimide on a substrate which comprises: (a) applying a first layer of fluorine-containing polyamic acid to the substrate; (b) partially imidizing the first layer of polyamic acid to provide a first polyimide layer; (c) applying a layer of polyamic acid over the first layer of polyimide wherein the polyamic acid is in a solvent of the formula ##STR12## wherein R 1 and R 2 are independently a hydrogen, a C 1 to C 6 alkyl moiety, or a ##STR13## R 5 is a C 1 to C 6 alkyl moiety; and R 3 and R 4 are independently hydrogen or a C 1 to C 6 alkyl moiety; and n is from 1 to 4; and (d) imidizing the polyamic acid.
Claim 22
Dependent Claim
11 words
The method of claim 18 wherein n is at least 2.
Claim 23
Dependent Claim
11 words
The method of claim 18 wherein the solvent comprises 2-methoxyethyl ether.
Claim 24
Dependent Claim
21 words
The method of claim 18 wherein the fluorinated polymer comprises the reaction product of 2,2-bis(3,4-dicarboxyphenyl)-hexafluoropropane dianhydride and at least one diamine.
Claim 25
Dependent Claim
21 words
The method of claim 18 wherein steps (a) to (d) are repeated to provide successive layers of polyimide on the substrate.
Claim 26
Dependent Claim
17 words
The method of claim 1 further including applying a patterned conductor layer between steps (b) and (c).
Claim 27
Dependent Claim
17 words
The method of claim 9 further including applying a patterned conductor layer between steps (b) and (c).
Claim 28
Dependent Claim
17 words
The method of claim 18 further including applying a patterned conductor layer between steps (b) and (c).
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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) | 1995-08-11 | 1996-02-10 | 1996-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-11 | 2000-02-10 | 2000-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-11 | 2004-02-10 | 2004-08-11 | $7700.00 | Window Closed / Lapsed |