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US4500562A
Expired / Lapsed
US
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Di-p-xylylene polymer and method for making the same
Assignee: ENERGY United States, UNITED STATES DEPARTMENT OF THE, Secretary of
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Filing: 1983-03-02
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Granted: 1985-02-19
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Expires: 2003-03-02
Abstract
Abstract A method and apparatus for forming an improved poly-p-xylylene film. Solid di-para-xylylene dimer is sublimed in a sublimation furnace at approximately 100° to 200° C. and subsequently conducted to a pyrolysis furnace where it is pyrolyzed to the diradical p-xylylene monomer while in the vapor state at approximately 600 degrees C. The diradical monomer is then introduced into a deposition chamber for deposition onto a suitable substrate. The deposition chamber includes electrodes for producing a low pressure plasma through which the diradical monomer passes prior to deposition. The interaction of the diradical monomer with the low pressure plasma results in the formation of poly-p-xylylene film which is exceptionally hard and thermally stable.
Inventors
- 👤 Randy K. Jahn
- 👤 Raimond Liepins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:10
CPC Classifications
B; B05; B05D; B05D1/00; B05D1/62
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
99 words
A method of making a polymerized p-xylylene film, comprising the steps of: subliming a solid di-p-xylylene at a first temperature to produce a sublimed di-p-xylylene vapor; pyrolyzing said sublimed di-p-xylylene vapor at a second temperature higher than said first temperature to produce a p-xylylene vapor; introducing said p-xylylene vapor into a deposition region wherein a low-temperature, low-pressure plasma is generated by means of an alternating electrical field applied to an inert gas in said region at a frequency of between approximately 30 and 300 hertz; and condensing said p-xylylene vapor onto a solid substrate located within said deposition region.
Claim 2
Independent Claim
99 words
A method of making a polymerized p-xylylene film, comprising the steps of: subliming a solid di-p-xylylene at a first temperature to produce a sublimed di-p-xylylene vapor; pyrolyzing said sublimed di-p-xylylene vapor at a second temperature higher than said first temperature to produce a p-xylylene vapor; introducing said p-xylylene vapor into a deposition region wherein a low-temperature, low-pressure plasma is generated by means of an alternating electrical field applied to an inert gas in said region at a frequency of between approximately 30 and 300 hertz; and condensing said p-xylylene vapor onto a solid substrate located within said deposition region.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein said low-pressure plasma is formed in nitrogen at a pressure of between approximately 10 and 300 millitorr.
Claim 4
Dependent Claim
42 words
The method defined in claim 1 wherein said p-xylylene vapor is passed through a plasma consisting of nitrogen at a pressure of between 10 and 300 millitorr excited by a 30 to 300 hertz alternating potential at approximately 150 to 500 volts.
Claim 5
Dependent Claim
24 words
The method of claim 1 wherein said low-pressure plasma is formed in argon at a system pressure of between approximately 10 and 300 millitorr.
Claim 6
Dependent Claim
25 words
The method of claim 1 wherein said substrate is cooled to approximately -30° to -45° C. prior to condensing said p-xylylene vapor onto said substrate.
Claim 7
Dependent Claim
17 words
The method defined in claim 1 wherein said first temperature is between approximately 100° and 250° C.
Claim 8
Dependent Claim
15 words
The method of claim 6 wherein said second temperature is between 450° and 700° C.
Claim 9
Dependent Claim
13 words
The method of claim 7 wherein said second temperature is approximately 600° C.
Claim 10
Dependent Claim
23 words
The method defined in claim 1 wherein said alternating electrical field is applied at a potential of between approximately 150 and 500 volts.
Claim 11
Dependent Claim
23 words
The method defined in claim 9 wherein said plasma is formed in nitrogen at a pressure of between approximately 10 and 300 millitorr.
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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) | 1988-02-19 | 1988-08-20 | 1989-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-19 | 1992-08-20 | 1993-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-19 | 1996-08-20 | 1997-02-19 | $7700.00 | Window Closed / Lapsed |