US4650108A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming hermetic seals
Assignee: United States, AS REPRESENTED BY ADMINISTRATOR OT NASA (NASA)
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Filing: 1985-08-15
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Granted: 1987-03-17
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Expires: 2005-08-15
Abstract
Abstract A firmly adherent film 16 of bondable metal, such as silver, is applied to the surface 10 of glass or other substrate by decomposing a layer 14 of a solution of a thermally decomposable metallo-organic deposition (MOD) compound such as silver neodecanoate in xylene. The MOD compound thermally decomposes into metal and gaseous by-products. Sealing is accomplished by depositing a layer 18 of bonding metal, such as solder or a brazing alloy, on the metal film and then forming an assembly with another high melting point metal surface 20 such as a layer of Kovar. When the assembly is heated above the temperature of the solder, the solder flows, wets the adjacent surfaces and forms a hermetic seal between the metal film 14 and metal surface 20 when the assembly cools.
Inventors
- 👤 Brian D. Gallagher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 04:45
CPC Classifications
C; C03; C03C; C03C27/00; C03C27/04; C03C27/042; C03C27/046; B; B23; B23K; B23K35/00; B23K35/001; C04; C04B; C04B37/00; C04B37/02; C04B37/023; C04B37/026; C04B2237/00; C04B2237/02; C04B2237/12; C04B2237/125; C04B2237/126; C04B2237/30; C04B2237/32; C04B2237/34; C04B2237/341; C04B2237/345; C04B2237/346; C04B2237/348; C04B2237/40; C04B2237/402; C04B2237/405; C04B2237/406; C04B2237/408; C04B2237/50; C04B2237/59; C04B2237/592; C04B2237/86
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
155 words
A method of forming a seal between a first metal surface having a high melting point and a second surface selected from glass, ceramic, refractory or semi-conductor comprising the steps of: applying a solution of a silver-organic compound in an organic solvent to the second surface to form a thin, uniform layer, said compound including a moiety containing an atom selected from O, N or S bridging a silver atom to an organic group; evaporating the solvent from the solution to form a layer of said compound; thermally decomposing the compound to form a film of silver adherent to the second surface; depositing a layer of low melting point metal bonding material on the film; placing the first surface on the layer of material to form an assembly; and heating the assembly to above the melting point of the material and soldering or brazing the second surface to the first surface to form a seal.
Claim 2
Independent Claim
155 words
A method of forming a seal between a first metal surface having a high melting point and a second surface selected from glass, ceramic, refractory or semi-conductor comprising the steps of: applying a solution of a silver-organic compound in an organic solvent to the second surface to form a thin, uniform layer, said compound including a moiety containing an atom selected from O, N or S bridging a silver atom to an organic group; evaporating the solvent from the solution to form a layer of said compound; thermally decomposing the compound to form a film of silver adherent to the second surface; depositing a layer of low melting point metal bonding material on the film; placing the first surface on the layer of material to form an assembly; and heating the assembly to above the melting point of the material and soldering or brazing the second surface to the first surface to form a seal.
Claim 3
Dependent Claim
35 words
A method according to claim 1 further including the step of selectively decomposing the layer of compound to form a pattern of silver film and removing the remainder of the solution from the second surface.
Claim 4
Dependent Claim
22 words
A method according to claim 1 in which the high melting point metal surface is a coating on the surface of substrate.
Claim 5
Dependent Claim
22 words
A method according to claim 1 in which the bondable metal comprises silver containing up to 10 atomic percent of other metals.
Claim 6
Dependent Claim
20 words
A method according to claim 4 in which the other metals are selected from Pt, Cr, Co, Ni or Bi.
Claim 7
Dependent Claim
20 words
A method according to claim 5 in which the compound is selected from carboxylates, amines, alkoxides or metal pyridine complexes.
Claim 8
Dependent Claim
46 words
A method according to claim 3 in which the compound is a carboxylate of the formula: ##STR2## where M is silver of an alloy thereof and R 1 , R 2 and R 3 are organic groups containing a total of 2 to 14 carbon atoms.
Claim 9
Dependent Claim
23 words
A method according to claim 7 in which R 1 , R 2 or R 3 contain a secondary or tertiary carbon atom.
Claim 10
Dependent Claim
17 words
A method according to claim 8 in which the compound is selected from neodecanoates or 2-ethyl hexanoates.
Claim 11
Dependent Claim
19 words
A method according to claim 1 in which the bonding material is selected from a solder or brazing alloy.
Claim 12
Dependent Claim
25 words
A method according to claim 1 further including the step of selectively applying said solution to portions of the second surface to form a pattern.
Claim 13
Dependent Claim
21 words
A method according to claim 11 in which the pattern is in the form of a border on the second surface.
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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) | 1990-03-16 | 1990-09-15 | 1991-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-16 | 1994-09-15 | 1995-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-16 | 1998-09-15 | 1999-03-17 | $7700.00 | Window Closed / Lapsed |