Patent US4019388A successfully refreshed from Google Patents.
US4019388A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Glass to metal seal
Assignee: Elsag International BV
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Filing: 1976-03-11
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Granted: 1977-04-26
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Expires: 1996-03-11
Abstract
Abstract A pressure sensitive Silicon chip is indirectly bonded to a Stainless Steel housing of an electronic pressure transmitter through an intermediate holder assembly. This indirect bonding prevents thermal cracking of the Silicon chip due to the difference in thermal expansion of the Stainless Steel housing and the Silicon chip. The holder assembly includes a Borosilicate glass tube having the Silicon chip bonded thereto which tube is soldered to a Nickel-Iron alloy holder by a eutectic alloy solder. In assembly, the Nickel-Iron holder is first brazed to the stainless Steel housing at a first temperature greater than the maximum non-destructive temperature of either the chip or the glass tube and the glass tube is then soldered to the Nickel-Iron holder at a lower temperature which will not destroy the chip or the tube holder.
Inventors
- 👤 II George R. Hall
- 👤 Jack M. White
- 👤 Roger L. Krechmery
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:37
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0041; G01L9/0051; G01L9/0052; G01L9/0054; G01L19/00; G01L19/06; G01L19/0627; G01L19/14; G01L19/147
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
70 words
A method of indirectly mounting a pressure sensitive Silicon element to a corrosion resistant metallic housing comprising the steps of: brazing a Nickel-Iron holder assembly to a corrosion resistant metallic stem; mounting the Silicon element to a glass holder assembly; soldering the Nickel-Iron holder assembly to the glass holder assembly; and soldering the corrosion resistant stem to the corrosion resistant housing to indirectly mount the Silicon element to the housing.
Claim 2
Independent Claim
70 words
A method of indirectly mounting a pressure sensitive Silicon element to a corrosion resistant metallic housing comprising the steps of: brazing a Nickel-Iron holder assembly to a corrosion resistant metallic stem; mounting the Silicon element to a glass holder assembly; soldering the Nickel-Iron holder assembly to the glass holder assembly; and soldering the corrosion resistant stem to the corrosion resistant housing to indirectly mount the Silicon element to the housing.
Claim 3
Independent Claim
81 words
A method of indirectly mounting a pressure sensitive Silicon element to a corrosion resistant metallic housing of a pressure transmitter through intermediate assemblies comprising the steps of: mounting the Silicon element to a glass assembly; brazing a Nickel-Iron assembly to the corrosion resistant metallic housing; metallizing a surface of the glass assembly; metallizing a surface of the Nickel-Iron assembly; providing a eutectic soldering material; and soldering the metallized surfaces of the glass and the Nickel-Iron assembly using the eutectic soldering material.
Claim 4
Independent Claim
81 words
A method of indirectly mounting a pressure sensitive Silicon element to a corrosion resistant metallic housing of a pressure transmitter through intermediate assemblies comprising the steps of: mounting the Silicon element to a glass assembly; brazing a Nickel-Iron assembly to the corrosion resistant metallic housing; metallizing a surface of the glass assembly; metallizing a surface of the Nickel-Iron assembly; providing a eutectic soldering material; and soldering the metallized surfaces of the glass and the Nickel-Iron assembly using the eutectic soldering material.
Claim 5
Dependent Claim
45 words
A method as set forth in claim 2 wherein said step of metallizing a surface of the glass assembly includes the steps of: evaporating a layer of Chrome on the surface of the glass assembly; and evaporating a layer of Gold on the Chrome layer.
Claim 6
Dependent Claim
34 words
A method as set forth in claim 3 wherein said step of metallizing a surface of the Nickel-Iron assembly includes the steps of evaporating a layer of Chrome and Gold on the Nickel-Iron assembly.
Claim 7
Dependent Claim
19 words
A method as set forth in claim 2 wherein said step of brazing is done in an inert atmosphere.
Claim 8
Independent Claim
80 words
A method of bonding a surface of Borosilicate glass to a surface of Nickel-Iron comprising the steps of: coating the glass surface with a thin layer of Chrome; coating the Chrome surface of the glass with a thin layer of Gold; coating the Nickel-Iron surface with a thin layer of Chrome; coating the Chrome surface of the Nickel-Iron with a thin layer of Gold; and soldering the coated glass layer to the coated Nickel-Iron layer using a Tin-Silver eutectic alloy.
Claim 9
Independent Claim
80 words
A method of bonding a surface of Borosilicate glass to a surface of Nickel-Iron comprising the steps of: coating the glass surface with a thin layer of Chrome; coating the Chrome surface of the glass with a thin layer of Gold; coating the Nickel-Iron surface with a thin layer of Chrome; coating the Chrome surface of the Nickel-Iron with a thin layer of Gold; and soldering the coated glass layer to the coated Nickel-Iron layer using a Tin-Silver eutectic alloy.
Claim 10
Dependent Claim
88 words
A mounting assembly for indirectly mounting a pressure sensitive Silicon chip to a corrosion resistant metallic housing of a pressure transmitter comprising: a Nickel-Iron holder brazed to the housing of the transmitter to provide a mounting surface; a glass holder having a coefficient of expansion similar to the Silicon chip and having a first surface soldered to the mounting surface of said Nickel-Iron surface and a second surface opposite said first surface; and a pressure sensitive Silicon chip being mounted to said second surface of said glass holder.
Claim 11
Dependent Claim
88 words
A mounting assembly for indirectly mounting a pressure sensitive Silicon chip to a corrosion resistant metallic housing of a pressure transmitter comprising: a Nickel-Iron holder brazed to the housing of the transmitter to provide a mounting surface; a glass holder having a coefficient of expansion similar to the Silicon chip and having a first surface soldered to the mounting surface of said Nickel-Iron surface and a second surface opposite said first surface; and a pressure sensitive Silicon chip being mounted to said second surface of said glass holder.
Claim 12
Dependent Claim
42 words
A mounting assembly as set forth in claim 7 wherein said glass holder is formed from Borosilicate glass into a tubular member having said Silicon chip mounted on one end of the tubular member to seal that end of the tubular member.
Claim 13
Dependent Claim
37 words
A mounting assembly as set forth in claim 8 wherein the end of said tubular member opposite said Silicon chip has a layer of Chrome deposited thereon and a layer of Gold deposited on the Chrome layer.
Claim 14
Dependent Claim
23 words
A mounting assembly as set forth in claim 9 wherein said Nickel-Iron holder has the mounting surface covered with a layer of Gold.
Claim 15
Dependent Claim
29 words
A mounting assembly as set forth in claim 10 wherein the covered surfaces of said glass holder and said Nickel-Iron holder are soldered together with a Tin-Silver eutectic alloy.
References Cited (Backward Citations)
US3305818A
Cited
US3697917A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |