US3922388A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making an encapsulated thick film resistor and associated encapsulated conductors for use in an electrical circuit
Assignee: Honeywell Inc
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Filing: 1974-11-20
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Granted: 1975-11-25
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Expires: 1994-11-20
Abstract
Abstract A method of making an encapsulated thick film resistor and an associated encapsulated conductor so that the stability of the resistor will be maintained at a precise level over an abnormally long period of time by first firing selected mixtures of positive and negative thick film resistor ink materials on a nonelectrically conductive substrate at a selected high temperature, jointly firing the resistor and conductor ink materials associated with this resistor at a temperature that is lower than the first mentioned temperature and which is at a level that will not allow any detrimental diffusion to occur between the conductor and the resistor materials, applying a resilient buffer material formed of a silicone polymer filled with magnesium oxide over the fired resistor and the fired conductor and then applying a hard outer glyptal coating over the resilient buffer.
Inventors
- 👤 Sergei Schebalin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:48
CPC Classifications
H; H01; H01C; H01C17/00; H01C17/02; H05; H05K; H05K1/00; H05K1/16; H05K1/167; H05K3/00; H05K3/22; H05K3/28
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
214 words
A METHOD OF MAKING AN ENCAPSULATED THICK FILM RESISTOR HAVING CONDUCTIVE PORTIONS ASSOCIATED WITH OPPOSITE ENDS THEREOF THAT FORM PORTIONS OF AN ELECTRICALLY CONDUCTIVE CIRCUIT, COMPRISING THE FIRST STEP OF SELECTING AN INK FROM A MIXTURE OF POSITIVE AND NEGATIVE RESISTOR INKS, THE SECOND STEP OF FIRING THE RESISTOR INK MIX IN AMORPHIC FORM AT 1000*C INTO A SINTERED STATE ONTO AN ELECTRICALLY NON-CONDUCTIVE SUBSTRATE, THE THIRD STEP OF SELECTING A CONDUCTIVE INK MATERIAL THAT HAS A SINTERIG TEMPERATURE SUBSTANTIALLY LOWER THAN THE SINTERING TEMPERATURE OF THE RESISTOR, THE FOURTH STEP OF FIRING SAID CONDUCTIVE INK AT A SINTERING TEMPERATURE OF ABOUT 550*C IN OVERLAPPING RELATIONSHIP WITH SAID OPPOSITE ENDS OF SAID RESISTOR ON THE SUBSTRATE WHEREBY THE TENDENCY TO DIFFUSION BETWEEN THE CONDUCTIVE AND RESISTIVE MATERIALS IS MINIMIZED AND WHEREBY A RESULTING TEMPERATURE COEFFICIENT OF RESISTIVITY VALUE OF THE REISTOR THAT IS PRODUCED IS WITHIN PLUS OR MINUS 20 PARTS PER MILLION PER DEGREE CENTIGRADE FROM ZERO, THE FIFTH STEP OF APPLYING A COATING OF RESILIENT BUFFER MATERIAL FORMED OF A SILICONE POLYMER FILLED WITH MAGNESIUM OXIDE TO COVER SAID RESISTOR AND THE SAID FIRED CONDUCTIVE INK AND THE SIXTH STEP OF APPLYING A LAYER OF IRON OXIDE WITH MAGNESIUM SILICATE SUSPENDED IN XYLENE TO COVER THE OUTER SURFACE OF SAID RESILIENT MATERIAL.
Claim 2
Independent Claim
214 words
A METHOD OF MAKING AN ENCAPSULATED THICK FILM RESISTOR HAVING CONDUCTIVE PORTIONS ASSOCIATED WITH OPPOSITE ENDS THEREOF THAT FORM PORTIONS OF AN ELECTRICALLY CONDUCTIVE CIRCUIT, COMPRISING THE FIRST STEP OF SELECTING AN INK FROM A MIXTURE OF POSITIVE AND NEGATIVE RESISTOR INKS, THE SECOND STEP OF FIRING THE RESISTOR INK MIX IN AMORPHIC FORM AT 1000*C INTO A SINTERED STATE ONTO AN ELECTRICALLY NON-CONDUCTIVE SUBSTRATE, THE THIRD STEP OF SELECTING A CONDUCTIVE INK MATERIAL THAT HAS A SINTERIG TEMPERATURE SUBSTANTIALLY LOWER THAN THE SINTERING TEMPERATURE OF THE RESISTOR, THE FOURTH STEP OF FIRING SAID CONDUCTIVE INK AT A SINTERING TEMPERATURE OF ABOUT 550*C IN OVERLAPPING RELATIONSHIP WITH SAID OPPOSITE ENDS OF SAID RESISTOR ON THE SUBSTRATE WHEREBY THE TENDENCY TO DIFFUSION BETWEEN THE CONDUCTIVE AND RESISTIVE MATERIALS IS MINIMIZED AND WHEREBY A RESULTING TEMPERATURE COEFFICIENT OF RESISTIVITY VALUE OF THE REISTOR THAT IS PRODUCED IS WITHIN PLUS OR MINUS 20 PARTS PER MILLION PER DEGREE CENTIGRADE FROM ZERO, THE FIFTH STEP OF APPLYING A COATING OF RESILIENT BUFFER MATERIAL FORMED OF A SILICONE POLYMER FILLED WITH MAGNESIUM OXIDE TO COVER SAID RESISTOR AND THE SAID FIRED CONDUCTIVE INK AND THE SIXTH STEP OF APPLYING A LAYER OF IRON OXIDE WITH MAGNESIUM SILICATE SUSPENDED IN XYLENE TO COVER THE OUTER SURFACE OF SAID RESILIENT MATERIAL.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |