US3780255A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for heat treatment of substrates
Assignee: Celanese Corp
•
Filing: 1971-09-30
•
Granted: 1973-12-18
•
Expires: 1991-09-30
Abstract
Abstract An apparatus for more efficiently creating high temperatures, particularly for the treatment of substrates. A central passage extends through the envelope and one electrode is disposed in the central passage. A second electrode is disposed around the envelope so that the electrodes are separated at least in part by the envelope. The gas conditions within the envelope are made to differ from the gas conditions exteriorly thereof and a radio frequency signal applied to the electrodes to excite the gas within the envelope to thereby generate a gaseous plasma. The amplitude of the radio frequency signal is, however, insufficient to generate a plasma outside the chamber defined by the envelope. Since the plasma does not contact the electrodes, the current flow between the electrodes is minimized and contamination of the gas by the electrodes is prevented. In addition, the surface area of the electrode in the central passage is substantially less than the surface area of the outer electrode thereby creating a plasma within the envelope which is more concentrated in the vicinity of the centrally disposed electrode. The plasma appears to induce a current in the centrally disposed electrode transverse to the axis thereof. This current is an order of magnitude higher than the average RF current between the electrodes and localized heating of the substrate is thus provided. A radio frequency balun transformer is provided for adjusting the power applied to the electrodes.
Inventors
- 👤 A Boom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:19
CPC Classifications
H; H01; H01F; H01F29/00; H01F29/08; H01F29/12; C; C21; C21D; C21D9/00; C21D9/52; C21D9/54; C21D9/56
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
76 words
Apparatus comprising: electrically insulative means defining a gas impervious envelope having a central passage extending thereinto; a first electrode disposed wholly exteriorly of said envelope; said electrode being disposed in part within said central passage; a second electrode disposed exteriorly of said envelope and separated at least in part from said first electrode by said envelope; and means for applying a radio frequency electrical signal to said electrodes to thereby generate a plasma within said envelope.
Claim 2
Dependent Claim
76 words
Apparatus comprising: electrically insulative means defining a gas impervious envelope having a central passage extending thereinto; a first electrode disposed wholly exteriorly of said envelope; said electrode being disposed in part within said central passage; a second electrode disposed exteriorly of said envelope and separated at least in part from said first electrode by said envelope; and means for applying a radio frequency electrical signal to said electrodes to thereby generate a plasma within said envelope.
Claim 3
Dependent Claim
24 words
The apparatus of claim 1 wherein said first electrode is a substrate to be heated without exposure to the plasma generated within said envelope.
Claim 4
Dependent Claim
36 words
The apparatus of claim 2 wherein said substrate comprises a plurality of electrically conductive fibers and wherein said radio frequency electrical signal is applied to said substrate through a rotating member in contact with said substrate.
Claim 5
Dependent Claim
62 words
The apparatus of claim 1 including means for reducing the pressure within said envelope to a value less than the value of the pressure within said central passage; and, wherein said radio frequency electrical signal has a potential sufficient to generate a plasma between said electrodes within said envelope but insufficient to generate a plasma between said electrodes externally of said envelope.
Claim 6
Dependent Claim
32 words
The apparatus of claim 4 wherein said central passage communicates with the atmosphere on opposite sides of said envelope; and, including means for reducing the pressure within said envelope below atmospheric pressure.
Claim 7
Dependent Claim
45 words
The apparatus of claim 5 wherein the surface area of one of said electrodes is large relative to the surface area of the other of said electrodes whereby the plasma generated within said envelope is concentrated in the proximity of said other of said electrodes.
Claim 8
Dependent Claim
20 words
The apparatus of claim 6 wherein the distance between said electrodes is substantially constant over the length of said envelope.
Claim 9
Dependent Claim
40 words
The apparatus of claim 1 wherein the surface area of said second electrode is large relative to the surface area of said first electrode whereby the plasma generated within said envelope is concentrated in the proximity of said first electrode.
Claim 10
Dependent Claim
22 words
The apparatus of claim 8 wherein the distance between said electrodes included in said envelope varies over the length of said envelope.
Claim 11
Dependent Claim
56 words
The apparatus of claim 1 wherein said gas impervious envelope comprises: a first elongated hollow member; a second elongated hollow member telescoped Within said first member; and, means for establishing a gas impervious seal between said first and second members at spaced points along the length thereof to define said gas impervious envelope between said electrodes.
Claim 12
Dependent Claim
47 words
The apparatus of claim 10 wherein said first member is a hollow cylinder; wherein said second member is a hollow cylinder substantially coextensive and coaxial with said first member; and, wherein said second electrode is a hollow cylinder only slightly larger in diameter than said first member.
Claim 13
Dependent Claim
26 words
The apparatus of claim 11 wherein said second electrode is a thin layer of metal conformed to the radially outer external surface of said first member.
Claim 14
Dependent Claim
52 words
Apparatus for treating a substrate comprising: electrically insulative means defining a gastight chamber; and, means including a first electrode and said substrate to be treated disposed exteriorly of said chamber on opposite sides thereof for generating a high frequency induced plasma within said chamber without generating a plasma exteriorly of said chamber.
Claim 15
Dependent Claim
52 words
Apparatus for treating a substrate comprising: electrically insulative means defining a gastight chamber; and, means including a first electrode and said substrate to be treated disposed exteriorly of said chamber on opposite sides thereof for generating a high frequency induced plasma within said chamber without generating a plasma exteriorly of said chamber.
Claim 16
Dependent Claim
23 words
The apparatus of claim 13 wherein the distance between said electrode and said substrate is substantially constant along the length of said chamber.
Claim 17
Dependent Claim
22 words
The apparatus of claim 14 wherein the surface area of said electrode is substantially greater than the surface area of said substrate.
Claim 18
Dependent Claim
57 words
The apparatus of claim 13 wherein said first electrode comprises: an electrically conductive plate surrounding at least a portion of said chamber; and, wherein said means for generating said high frequency induced plasma comprises: means for generating a radio frequency signal; circuit means for applying said radio frequency signal to said substrate and said electrically conductive plate.
Claim 19
Dependent Claim
50 words
The apparatus of claim 16 wherein said generating means includes: a source of radio frequency signal; and, transformer means for coupling said radio frequency signal from said source to said circuit means, said transformer means including primary and secondary coils, and means for varying the mutual inductance of said coils.
Claim 20
Dependent Claim
77 words
The apparatus of claim 17 wherein said means for varying the mutual inductance of said coils comprises: first and second elongated, axially spaced, insulative cores disposed substantially coaxially relative to each other, said primary and secondary coils each being wound on one of said cores coaxially therewith; means for axially rotating one of said cores relative to the other; and, means responsive to the relative rotation of said cores for varying the axial spacing between said coils.
Claim 21
Dependent Claim
86 words
The apparatus of claim 18 wherein said means for varying the axial spacing between said coils comprises a helical groove running generally circumferentially along at least a portion of the length of said one of said cores, said groove generally conforming in shape to said coil wound on said one of said cores, said groove receiving said coil wound on said one of said cores whereby said coil moves axially along said one of said cores responsively to the rotation of said one of said cores.
References Cited (Backward Citations)
US2636919A
Cited
US1495175A
Cited
US2163647A
Cited
US2282317A
Cited
US2887666A
Cited
US3182982A
Cited
US3146336A
Cited
US3211886A
Cited
US3204080A
Cited
US3383163A
Cited
US3356933A
Cited
US3405301A
Cited
US3671195A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |