Method for producing a metal film resistor
AssigneeKiyokawa Plating Industries, Co., Ltd.
InventorHajime Kiyokawa
Life of this patent
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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.degree.-40.degree. C. and a pH of 6-8.
Claims7
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.degree.-40.degree. C. and a pH of 6-8 to deposit copper-nickel alloy with a copper ratio of from 40 to 65 wt %.
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 %.
Dependencies are inferred from the claim text.