Patent US3607389A successfully refreshed from Google Patents.
US3607389A
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Metallic film resistors
Assignee: ELETTROTECNICA CHIMICA ITALIAN
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Filing: 1968-10-18
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Granted: 1971-09-21
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Expires: 1988-10-18
Abstract
Abstract Precision resistors are produced by depositing, at a temperature of from 40 to 90* C., a nickel-phosphorus film upon former rods of steatite from an electroless plating solution having a pH value of 5 to 7 and containing specified amounts of a water soluble hypophosphite, nickel sulfate, soluble pyrophosphate, a water soluble orthophosphate and a water soluble salt of ethylenediaminetetraacetic acid, the resulting nickel-phosphorus film resistor rods being subsequently subjected to heat stabilization; the temperature coefficient of resistance of the resulting precision resistors is in the vicinity of zero.
Inventors
- 👤 Giovanni Canegallo
- 👤 Ubaldo Costa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:56
CPC Classifications
H; H01; H01C; H01C17/00; H01C17/06; H01C17/075; H01C17/14; H01C17/18
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
21 words
A process according to claim 1, in which constituent (c) is present in a concentration of 0.005 to 0.09 g. moles/1.
Claim 2
Dependent Claim
16 words
A process according to claim 1, in which the plating temperature is from 40 to 90*C.
Claim 3
Dependent Claim
65 words
A process according to claim 1, in which the aqueous electroless plating solution is a solution resulting by dissolving in distilled water per litre of solution the following ingredients or their chemical equivalents: nickel sulfate approximately 25 g., water soluble hypophosphite approximately 25 g., water soluble pyrophosphate approximately 50 g. water soluble salt of EDTA approximately 30 g. and water soluble orthophosphate approximately 7 g.
Claim 4
Dependent Claim
65 words
A process according to claim 1, in which the aqueous electroless plating solution is a solution resulting by dissolving in distilled water per litre of solution the following ingredients or their chemical equivalents: nickel sulfate approximately 26 g., water soluble hypophosphite approximately 25 g., water soluble pyrophosphate approximately 49 g., water soluble salt of EDTA approximately 27 g. and water soluble orthophosphate approximately 6.6 g.
References Cited (Backward Citations)
US3024134A
Cited
US3172074A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |