US5560812A
Expired / Lapsed
US
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Method for producing a metal film resistor
Assignee: Kiyokawa Plating Industries Co Ltd
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Filing: 1994-12-15
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Granted: 1996-10-01
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Expires: 2014-12-15
Abstract
Abstract A method for producing a metal film resistor including at least an insulating substrate, a resistor film of copper-nickel alloy formed on the surface of the insulating substrate, and a pair of terminals which are in contact with the resistor film is provided. The method includes a step of depositing the copper-nickel alloy by electroplating from an aqueous pyrophosphate bath containing a copper salt and a nickel salt at a bath temperature of 20°-40° C. and a pH of 6-8.
Inventors
- 👤 Hajime Kiyokawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:15
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/50; C04B41/51; C04B41/5144; C04B41/52; C04B41/80; C04B41/81; C04B41/85; C04B41/88; C04B41/89; C25; C25D; C25D3/00; C25D3/02; C25D3/56; C25D3/58; H; H01; H01C; H01C17/00; H01C17/06; H01C17/075; H01C17/14; H01C17/18; C04B2111/00; C04B2111/00474; C04B2111/00844
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
99 words
A method for producing a metal film resistor including at least an insulating substrate having a surface, a resistor film of copper-nickel alloy formed on said surface of said insulating substrate, and a pair of terminals which are in contact with said resistor film, said method comprising: a step of electrolyzing an aqueous pyrophosphate bath containing 0.005-0.030 mole/L of cupric sulfate, 0.07-0.30 mole/L of nickel sulfate and 0.20-0.50 mole/L of potassium pyrophosphate at a bath temperature of 20°-40° C. and a pH of 6-8 to deposit copper-nickel alloy with a copper ratio of from 40 to 65 wt %.
Claim 2
Independent Claim
99 words
A method for producing a metal film resistor including at least an insulating substrate having a surface, a resistor film of copper-nickel alloy formed on said surface of said insulating substrate, and a pair of terminals which are in contact with said resistor film, said method comprising: a step of electrolyzing an aqueous pyrophosphate bath containing 0.005-0.030 mole/L of cupric sulfate, 0.07-0.30 mole/L of nickel sulfate and 0.20-0.50 mole/L of potassium pyrophosphate at a bath temperature of 20°-40° C. and a pH of 6-8 to deposit copper-nickel alloy with a copper ratio of from 40 to 65 wt %.
Claim 3
Dependent Claim
47 words
The method for producing a metal film resistor in accordance with claim 1, which further comprises, prior to said step of depositing copper-nickel alloy, a step of depositing a metal undercoat which serves as a foundation for said copper-nickel alloy on said insulating substrate by electroless plating.
Claim 4
Dependent Claim
55 words
The method for producing a metal film resistor in accordance with claim 1, which further comprises, prior to said step of depositing copper-nickel alloy, steps of subjecting said insulating substrate to an activation treatment and depositing a nickel undercoat which serves as a foundation for said copper-nickel alloy on said insulating substrate by electroless plating.
Claim 5
Dependent Claim
71 words
The method for producing a metal film resistor in accordance with claim 1, wherein said step of depositing copper-nickel alloy is performed by electrolyzing said pyrophosphate bath by using separate anodes of copper and nickel and a plating current is distributed between the copper anode and the nickel anode in a constant proportion, thereby to make a concentration ratio of nickel ion to copper ion in said pyrophosphate bath substantially constant.
Claim 6
Dependent Claim
37 words
The method for producing a metal film resistor in accordance with claim 1, further comprising a step of subjecting said copper-nickel alloy to a heat-treatment under a nitrogen atmosphere at a temperature of 500° C. or above.
Claim 7
Independent Claim
95 words
A method for producing a metal film resistor including at least an insulating substrate having a surface, a resistor film of copper-nickel alloy formed on said surface of said insulating substrate, and a pair of terminals which are in contact with said resistor film, said method comprising: a step of electrolyzing a pyrophosphate bath by using separate anodes of copper and nickel while distributing a plating current between the copper anode and the nickel anode at a predetermined ratio, thereby to deposit copper-nickel alloy with a copper ratio of from 40 to 65 wt %.
Claim 8
Independent Claim
95 words
A method for producing a metal film resistor including at least an insulating substrate having a surface, a resistor film of copper-nickel alloy formed on said surface of said insulating substrate, and a pair of terminals which are in contact with said resistor film, said method comprising: a step of electrolyzing a pyrophosphate bath by using separate anodes of copper and nickel while distributing a plating current between the copper anode and the nickel anode at a predetermined ratio, thereby to deposit copper-nickel alloy with a copper ratio of from 40 to 65 wt %.
Claim 9
Dependent Claim
19 words
The method of claim 6, wherein: said pyrophosphate bath is an aqueous pyrophosphate bath having a pH of 7-9.
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) | 1999-10-01 | 2000-04-01 | 2000-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-10-01 | 2004-04-01 | 2004-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-10-01 | 2008-04-01 | 2008-10-01 | $7700.00 | Window Closed / Lapsed |