US4590103A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the preparation of thin polyimide film
Assignee: Siemens AG
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Filing: 1984-06-20
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Granted: 1986-05-20
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Expires: 2004-06-20
Abstract
Abstract The invention relates to a method for the preparation of thin polyimide layers by applying a solution of a polyimide prepolymer to a substrate, and subsequently annealing, and has as its object the provision of a method of this type in such a way that the preparation of layers with layer thicknesses of ≦0.2 μm is made possible which layers have a homogeneous character and exhibit good adhesion. For this purpose, the invention provides that film-forming prepolymers of highly heat-resistant polyimides are used which prepolymers give off a high percentage of volatile products in annealing. The method according to the invention is particularly suitable for the production of orientation layers for liquid-crystal displays.
Inventors
- 👤 Hellmut Ahne
- 👤 Wolfgang Kleeberg
- 👤 Roland Rubner
- 👤 Hans Kruger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:37
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1337; G02F1/133711; G02F1/133723; C; C03; C03C; C03C17/00; C03C17/28; C03C17/32; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1003
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
137 words
In a method for preparing polyimide layers having a thickness of less than about 0.2 μm, wherein a solution of a polyimide prepolymer is applied to a substrate in the form of a film and the applied film is thereafter annealed to convert the prepolymer to polyimide, the improvement wherein said prepolymer is a film-forming prepolymer of a highly heat-resistant polyimide, said solution of said prepolymer also contains a compound selected from a diazoquinone, an oligomeric ester or ether having an aliphatic or cycloaliphatic structural element, polymethylmethacrylate or a polyolefin sulfone, which compound is volatilized in the annealing process, and, during annealing, said solution gives off a percentage of volatile products, relative to its total weight, which is sufficiently large to result in a reduction in the thickness of the applied film of at least about 40%.
Claim 2
Dependent Claim
137 words
In a method for preparing polyimide layers having a thickness of less than about 0.2 μm, wherein a solution of a polyimide prepolymer is applied to a substrate in the form of a film and the applied film is thereafter annealed to convert the prepolymer to polyimide, the improvement wherein said prepolymer is a film-forming prepolymer of a highly heat-resistant polyimide, said solution of said prepolymer also contains a compound selected from a diazoquinone, an oligomeric ester or ether having an aliphatic or cycloaliphatic structural element, polymethylmethacrylate or a polyolefin sulfone, which compound is volatilized in the annealing process, and, during annealing, said solution gives off a percentage of volatile products, relative to its total weight, which is sufficiently large to result in a reduction in the thickness of the applied film of at least about 40%.
Claim 3
Dependent Claim
27 words
A method according to claim 1 wherein said prepolymer, during the annealing, gives off high molecular weight alcohols as volatile products in the formation of the polyimide.
Claim 4
Dependent Claim
17 words
A method according to claim 1 wherein said solution of said prepolymer has added thereto a silane.
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) | 1989-05-19 | 1989-11-18 | 1990-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-19 | 1993-11-18 | 1994-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-19 | 1997-11-18 | 1998-05-20 | $7700.00 | Window Closed / Lapsed |