US4686414A
Expired / Lapsed
US
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Enhanced wetting of liquid metal alloy ion sources
Assignee: The AT&T MVPD Group LLC
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Filing: 1984-11-20
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Granted: 1987-08-11
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Expires: 2004-11-20
Abstract
Abstract A process for enhancing the wettability of evaporation elements, such as substrates and metal reservoirs used in liquid metal ion sources, and the elements so produced wherein a coating material is wettably coated onto the evaporation element at a coating temperature greater than the ion source operating temperature. The coated element is cooled to the operating temperature, and then contacted with the molten ion source alloy. The coating material is selected to wet the substrate or reservoir at the coating temperature, but to be itself wet by the ion source alloy at the ion source operating temperature. The preferred coating metal is gold, which is first applied by electrodeposition onto the evaporation element, and the evaporation element and coating are heated to a coating temperature of about 800° C. to complete the coating step. The coated evaporation element is cooled to the source operating temperature of 200° C.-300° C. and dipped into the ion source alloy, which may be an alloy such as lead-gold-arsenic or lead-gold-antimony.
Inventors
- 👤 Charles M. McKenna
- 👤 Irwin R. Sharapata
- 👤 William M. Clark, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:46
CPC Classifications
H; H01; H01J; H01J27/00; H01J27/02; H01J27/26; H01J37/00; H01J37/02; H01J37/04; H01J37/08
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
144 words
A process for preparing an evaporation element of enhanced wettability used in liquid metal ion sources to evaporate an ion source alloy at an operating temperature, comprising the steps of: selecting a coating material, the coating material being selected to wet the evaporation element at a temperature greater than the operating temperature of the liquid metal ion source alloy, to be wet by the source alloy at the operating temperature, and to not increase substantially the melting point of the source alloy when dissolved therein; coating the evaporation element with the coating material at a coating temperature sufficiently high so that a liquid layer is formed adjacent the surface of the evaporation element; and contacting the ion source alloy to the coated evaporation element at about the operating temperature to establish a first wetted layer of the ion source alloy on the evaporation element.
Claim 2
Dependent Claim
144 words
A process for preparing an evaporation element of enhanced wettability used in liquid metal ion sources to evaporate an ion source alloy at an operating temperature, comprising the steps of: selecting a coating material, the coating material being selected to wet the evaporation element at a temperature greater than the operating temperature of the liquid metal ion source alloy, to be wet by the source alloy at the operating temperature, and to not increase substantially the melting point of the source alloy when dissolved therein; coating the evaporation element with the coating material at a coating temperature sufficiently high so that a liquid layer is formed adjacent the surface of the evaporation element; and contacting the ion source alloy to the coated evaporation element at about the operating temperature to establish a first wetted layer of the ion source alloy on the evaporation element.
Claim 3
Dependent Claim
53 words
The process of claim 1, wherein said step of coating comprises the steps of: depositing a layer of the coating material onto the evaporation element at ambient temperature; and heating the evaporation element and coating layer to a coating temperature whereat the coating wets the evaporation element by forming a liquid layer thereagainst.
Claim 4
Dependent Claim
30 words
The process of claim 1, wherein said step of coating is preceded by the step of: treating the evaporation element to improve adherance between the coating material and the element.
Claim 5
Dependent Claim
21 words
The process of claim 3, wherein said step of treating is accomplished by placing a second coating on the evaporation element.
Claim 6
Dependent Claim
25 words
The process of claim 1, wherein said step of contacting is accomplished by dipping the evaporation element into a pool of the ion source material.
Claim 7
Dependent Claim
14 words
The process of claim 2, wherein the evaporation element is an evaporation substrate needle.
Claim 8
Dependent Claim
32 words
The process of claim 1, wherein the coating material is gold, and the ion source alloy is an alloy selected from the group consisting of a lead-gold-antimony alloy and a lead-gold-arsenic alloy.
Claim 9
Dependent Claim
30 words
The process of claim 1, wherein the evaporation element is made of a material selected from the group consisting of steel, nickel, molybdenum, tungsten, and rhenium, and a metal carbide.
Claim 10
Dependent Claim
13 words
An evaporation element of enhanced wettability, prepared by the process of claim 1.
Claim 11
Dependent Claim
88 words
A process for enhancing the wettability of a liquid metal ion source evaporation element by an ion source alloy, comprising the steps of: depositing a layer of gold onto the evaporation element; heating the evaporation element with the gold layer thereon to a coating temperature greater than about 600° C.; and contacting the ion source alloy to the coated evaporation element at a temperature of from about 200° C. to about 300° C. to establish a first wetted layer of the ion source alloy on the evaporation element.
Claim 12
Dependent Claim
88 words
A process for enhancing the wettability of a liquid metal ion source evaporation element by an ion source alloy, comprising the steps of: depositing a layer of gold onto the evaporation element; heating the evaporation element with the gold layer thereon to a coating temperature greater than about 600° C.; and contacting the ion source alloy to the coated evaporation element at a temperature of from about 200° C. to about 300° C. to establish a first wetted layer of the ion source alloy on the evaporation element.
Claim 13
Dependent Claim
22 words
The process of claim 10, wherein the ion source alloy is an alloy selected from the group consisting of lead-gold-antimony and lead-gold-arsenic.
Claim 14
Dependent Claim
42 words
The process of claim 10, including the further step of: depositing a layer of nickel onto the evaporation element, prior to said step of depositing the layer of gold, so that the layer of gold is deposited over the layer of nickel.
Claim 15
Dependent Claim
12 words
The process of claim 10, wherein the evaporation element is a needle.
Claim 16
Dependent Claim
22 words
The process of claim 10, wherein the temperature in said step of heating is from about 600° C. to about 1000° C.
Claim 17
Dependent Claim
20 words
The process of claim 10, wherein the thickness of the gold deposit is from about 0.1 to about 1.0 micrometers.
Claim 18
Dependent Claim
25 words
The process of claim 10, wherein said step of contacting includes the step of dipping the coated element into a pool of the source alloy.
Claim 19
Dependent Claim
29 words
The process of claim 10, wherein said step of contacting includes the step of placing a pellet of the ion source alloy in contact with the coated evaporation element.
Claim 20
Dependent Claim
18 words
The process of claim 10, wherein said step of depositing a layer of gold is accomplished by electroplating.
Claim 21
Dependent Claim
110 words
A liquid metal ion source element comprising: (a) an ion source substrate; (b) a layer of a coating material adjacent and substantially covering the surface of said source substrate, said coating material being characterized as readily wetting the surface of said source substrate at a first given temperature; and (c) a layer of an ion source alloy adjacent and substantially covering the surface of said coating material layer, said coating material being further characterized as being readily wetted by said ion source alloy at a second given temperature that is less than said first given temperature, said second given temperature being approximately the operating temperature of said ion source element.
Claim 22
Dependent Claim
110 words
A liquid metal ion source element comprising: (a) an ion source substrate; (b) a layer of a coating material adjacent and substantially covering the surface of said source substrate, said coating material being characterized as readily wetting the surface of said source substrate at a first given temperature; and (c) a layer of an ion source alloy adjacent and substantially covering the surface of said coating material layer, said coating material being further characterized as being readily wetted by said ion source alloy at a second given temperature that is less than said first given temperature, said second given temperature being approximately the operating temperature of said ion source element.
Claim 23
Dependent Claim
41 words
The ion source of claim 19 wherein said coating material is further characterized as not significantly increasing the melting point of said ion source alloy due to a portion of said coating material layer disolving into said ion source alloy layer.
Claim 24
Dependent Claim
44 words
The ion source of claim 20 wherein said ion source substrate includes a layer of a bond-enhancing material as the surface portion of said ion source subtrate, said bond-enhancing material being characterized as reactively bonding with said coating material at said first given temperature.
Claim 25
Dependent Claim
15 words
The ion source of claim 21 wherein said coating material is substantially comprised of gold.
Claim 26
Dependent Claim
15 words
The ion source of claim 22 wherein said bond-enhancing material is substantially comprised of nickel.
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) | 1990-08-10 | 1991-02-09 | 1991-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-10 | 1995-02-09 | 1995-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-10 | 1999-02-09 | 1999-08-11 | $7700.00 | Window Closed / Lapsed |