Patent US4935305A successfully refreshed from Google Patents.
US4935305A
Expired / Lapsed
US
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Method of forming a plating layer on ceramic chip surfaces and electronic parts thereby manufactured
Assignee: Individual
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Filing: 1988-12-15
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Granted: 1990-06-19
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Expires: 2008-12-15
Abstract
Abstract This invention relates to a method of forming a plating layer on ceramic chip surfaces by electroless plating, and to electronic parts manufactured by this method. Such electronic parts include a metal film fixed resistor, a capacitor, a resistor for sensing purposes and a patterned substrate, for example. Ceramic chips are immersed in a plating solution containing chromium chloride, nickel sulfide, sodium hypophosphite, a chelating agent and thiourea. Then each ceramic chip is coated with a plating layer by electroless nickel plating while adjusting pH value of the plating solution with a pH regulating liquid. The resulting electronic parts have an initial resistance of 0.02 to 100 ohm or more and a temperature coefficient of resistance of a two-digit figure or less in ppm.
Inventors
- 👤 Takashi Kanehiro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:31
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/005; H01G4/008; C; C23; C23C; C23C18/00; C23C18/16; C23C18/48; C23C18/50; H01C; H01C7/00; H01C7/003; Y; Y10; Y10S; Y10S204/00; Y10S204/13; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
88 words
A device comprising a ceramic substrate having at least one surface; and a layer formed on the at least one layer to a thickness of 0.1 microns to several tens of microns, and comprising a ternary or multiplex alloy of at least tens of microns, and comprising a ternary or multiplex alloy of at least nickel, chromium, and phosphorus, so that the device has an initial resistance of 0.02 ohm to at least 100 ohms, and a temperature coefficient of resistance of two digits or less in ppm.
Claim 2
Independent Claim
88 words
A device comprising a ceramic substrate having at least one surface; and a layer formed on the at least one layer to a thickness of 0.1 microns to several tens of microns, and comprising a ternary or multiplex alloy of at least tens of microns, and comprising a ternary or multiplex alloy of at least nickel, chromium, and phosphorus, so that the device has an initial resistance of 0.02 ohm to at least 100 ohms, and a temperature coefficient of resistance of two digits or less in ppm.
Claim 3
Dependent Claim
24 words
The device of claim 1, wherein the layer comprises a ternary or multiplex alloy of nickel, chromium, phosphorus, and one or more other metals.
Claim 4
Dependent Claim
16 words
The device of claim 1, wherein the device has an initial resistance of over 100 ohms.
Claim 5
Independent Claim
135 words
A method of plating a ceramic substrate comprising the steps of mixing 2 to 3.5 g/l of chromium chloride, 4 to 7.5 g/l metallic content of nickel sulfide, 4 to 7.5 g/l of sodium hypophosphite, 0.001 to 0.002 g/l of thiourea, and a chelating agent in an amount proportion the amount of aforementioned metallic compounds, to form a plating solution; placing the ceramic substrate into said plating solution; continually adjusting the pH value to be between 3.5 to 4.8 pH of said plating solution by adding a pH regulating liquid; adjusting the temperature of the plating solution to be between 80° C. to 93° C.; and electroless plating the ceramic substrate so that at least one surface thereof has formed thereon a layer of ternary or multiplex alloy of at least nickel, chromium and phosphorus.
Claim 6
Independent Claim
135 words
A method of plating a ceramic substrate comprising the steps of mixing 2 to 3.5 g/l of chromium chloride, 4 to 7.5 g/l metallic content of nickel sulfide, 4 to 7.5 g/l of sodium hypophosphite, 0.001 to 0.002 g/l of thiourea, and a chelating agent in an amount proportion the amount of aforementioned metallic compounds, to form a plating solution; placing the ceramic substrate into said plating solution; continually adjusting the pH value to be between 3.5 to 4.8 pH of said plating solution by adding a pH regulating liquid; adjusting the temperature of the plating solution to be between 80° C. to 93° C.; and electroless plating the ceramic substrate so that at least one surface thereof has formed thereon a layer of ternary or multiplex alloy of at least nickel, chromium and phosphorus.
Claim 7
Dependent Claim
40 words
The method of claim 4, wherein the plating solution contains one or more other metal compounds, and wherein the layer formed on the substrate surface comprises a ternary or multiplex layer of nickel, chromium, phosphorus, and one or more metals.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-06-18 | 1993-12-18 | 1994-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-18 | 1997-12-18 | 1998-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-18 | 2001-12-18 | 2002-06-19 | $7700.00 | Window Closed / Lapsed |