US4068022A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods of strengthening bonds
Assignee: AT&T Inc
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Filing: 1974-12-10
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Granted: 1978-01-10
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Expires: 1994-12-10
Abstract
Abstract The adherence of thin-film conductors to supporting substrates, and therefore the strength of external lead bonds made to the conductors, is increased by forming the conductors first and then heat treating them in air. The conductors may be formed from layers of titanium, palladium and gold sequentially deposited on the substrate or, in order to reduce the amount of gold, a portion of it may be replaced by copper and nickel.
Inventors
- 👤 William F. Glick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:25
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/24; H05K3/244; H01; H01B; H01B1/00; H05K3/10; H05K3/108; H05K3/38; H05K3/388; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0364; H05K2201/0367; H05K2203/00; H05K2203/07; H05K2203/0703; H05K2203/0723; H05K2203/11; H05K2203/1105; H05K3/02; H05K3/06; H05K3/061; H05K3/062; H10; H10W; H10W70/00; H10W70/60; H10W70/62; H10W70/65; H10W70/654; H10W70/655
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
104 words
A method of strengthening the bond between a thin-film conductor and an alumina substrate on which the conductor is formed, which comprises the sequential steps of: depositing at least two metal layers, the first of which is titanium and the second is palladium, on said substrate to form a thin film of conductive material thereon; removing a portion of the conductive material to form at least one thin-film conductor from said material, said conductor having exposed edges; and heating the substrate and conductor for a predetermined period in an oxidizing atmosphere to improve the strength of the bond between the conductor and the substrate.
Claim 2
Independent Claim
104 words
A method of strengthening the bond between a thin-film conductor and an alumina substrate on which the conductor is formed, which comprises the sequential steps of: depositing at least two metal layers, the first of which is titanium and the second is palladium, on said substrate to form a thin film of conductive material thereon; removing a portion of the conductive material to form at least one thin-film conductor from said material, said conductor having exposed edges; and heating the substrate and conductor for a predetermined period in an oxidizing atmosphere to improve the strength of the bond between the conductor and the substrate.
Claim 3
Independent Claim
105 words
A method of improving bond strength between a thin film conductor and an alumina substrate on which the conductor is formed, comprising the sequential steps of: a. depositing successive layers of an adhesive metal of titanium and a conductive metal of palladium starting with the adhesive metal against the substrate; b. removing those portions of the adhesive and conductive metal layer not needed for the conductor to form and expose the edges of said conductor; and c. heating the substrate, and conductor so formed, in air for a predetermined length of time to improve the strength of the bond between the conductor and the substrate.
Claim 4
Independent Claim
105 words
A method of improving bond strength between a thin film conductor and an alumina substrate on which the conductor is formed, comprising the sequential steps of: a. depositing successive layers of an adhesive metal of titanium and a conductive metal of palladium starting with the adhesive metal against the substrate; b. removing those portions of the adhesive and conductive metal layer not needed for the conductor to form and expose the edges of said conductor; and c. heating the substrate, and conductor so formed, in air for a predetermined length of time to improve the strength of the bond between the conductor and the substrate.
Claim 5
Dependent Claim
47 words
A method, as recited in claim 2, wherein the step of depositing the metal layers comprises: a. evaporating a first layer of titanium; and then b. depositing on said first layer at least a second layer of a metal selected from the group comprising palladium and platinum.
Claim 6
Dependent Claim
43 words
A method, as recited in claim 3, wherein the depositing step (b) comprises the further step of: depositing a third layer by plating a conductive metal on the second layer, said third layer being selected from the group comprising copper, nickel and gold.
Claim 7
Dependent Claim
44 words
A method, as recited in claim 4, wherein the step of heating comprises: heating the substrate and conductor in air at 250° C for 5 hours to inrease the adherence of the conductor to the substrate and, thereby the strength of bonds made thereto.
Claim 8
Independent Claim
124 words
A method of strengthening the bond between a thin film conductor and an alumina substrate on which the conductor is formed comprising the sequential steps of: evaporating a layer of titanium on the alumina substrate; evaporating a layer of palladium on the titanium; plating a layer of copper on the palladium; plating a layer of nickel on the copper; plating a layer of gold on the nickel, the combined evaporated and plated layers forming a single thin-film coating of conductive material on the substrate; removing at least a portion of the material to form a thin-film conductor; and heating substrate and the conductor for a predetermined period of time in air to improve the strength of the bond between the conductor and the substrate.
Claim 9
Independent Claim
124 words
A method of strengthening the bond between a thin film conductor and an alumina substrate on which the conductor is formed comprising the sequential steps of: evaporating a layer of titanium on the alumina substrate; evaporating a layer of palladium on the titanium; plating a layer of copper on the palladium; plating a layer of nickel on the copper; plating a layer of gold on the nickel, the combined evaporated and plated layers forming a single thin-film coating of conductive material on the substrate; removing at least a portion of the material to form a thin-film conductor; and heating substrate and the conductor for a predetermined period of time in air to improve the strength of the bond between the conductor and the substrate.
Claim 10
Dependent Claim
26 words
A method as recited in claim 6, wherein the heating step is performed at a temperature between 200° and 400° C for 1 to 8 hours.
Claim 11
Dependent Claim
27 words
A method as recited in claim 7, wherein the titanium thickness is between 1700 and 2500A, the palladium is about 3000A, and the gold about 20,000A thick.
References Cited (Backward Citations)
US3290127A
Cited
US3386894A
Cited
US3528893A
Cited
US3665254A
Cited
US3765970A
Cited
US3686080A
Cited
US3890177A
Cited
US3708403A
Cited
US3783056A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-09 | 1981-07-11 | 1982-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-09 | 1985-07-11 | 1986-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-09 | 1989-07-11 | 1990-01-10 | $7700.00 | Window Closed / Lapsed |