Patent US4146673A successfully refreshed from Google Patents.
US4146673A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of film resistor laser trimming and composition of removable coating used therein
Assignee: EIDP Inc
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Filing: 1977-10-27
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Granted: 1979-03-27
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Expires: 1997-10-27
Abstract
Abstract A process of film resistor laser trimming. The process involves coating a resistor prior to trimming with a removable insulative material which absorbs and traps trimming debris, thus minimizing or preventing deposition of same on the trimmed resistor surface. Formation of conductive paths otherwise created over the surface of the resistor by the trimming debris is precluded thereby, thus enabling greater accuracy with respect to trimmed resistor measurement. The coating used is a composition of phenyl polysiloxane with silica dispersed therein.
Inventors
- 👤 Ronald C. Headley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:07
CPC Classifications
H; H01; H01C; H01C17/00; H01C17/22; H01C17/24; H01C17/242; B; B23; B23K; B23K26/00; B23K26/009; B23K26/18; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
40 words
A method of laser trimming a film resistor, comprising in sequence: (a) coating said resistor with an insulative coating composition consisting essentially of phenyl polysiloxane fluid with finely divided silica dispersed therein, and (b) trimming said resistor by laser energy.
Claim 2
Independent Claim
40 words
A method of laser trimming a film resistor, comprising in sequence: (a) coating said resistor with an insulative coating composition consisting essentially of phenyl polysiloxane fluid with finely divided silica dispersed therein, and (b) trimming said resistor by laser energy.
Claim 3
Independent Claim
58 words
A method of laser trimming a film resistor, comprising in sequence: (a) coating said resistor with a removable, electrically insulative composition consisting essentially of 5-10 weight percent finely divided silica dispersed in phenyl polysiloxane fluid, (b) adjusting resistance of said resistor by laser removal of resistor material, and (c) removing said coating material from the adjusted resistor surface.
Claim 4
Independent Claim
58 words
A method of laser trimming a film resistor, comprising in sequence: (a) coating said resistor with a removable, electrically insulative composition consisting essentially of 5-10 weight percent finely divided silica dispersed in phenyl polysiloxane fluid, (b) adjusting resistance of said resistor by laser removal of resistor material, and (c) removing said coating material from the adjusted resistor surface.
Claim 5
Dependent Claim
22 words
The method of claim 2 wherein said removing of coating composition from the trimmed resistor surface is by washing in isopropyl alcohol.
Claim 6
Dependent Claim
18 words
A film resistor coated with a composition consisting essentially of finely divided silica dispersed in phenyl polysiloxane fluid.
Claim 7
Dependent Claim
18 words
A film resistor coated with a composition consisting essentially of finely divided silica dispersed in phenyl polysiloxane fluid.
Claim 8
Dependent Claim
17 words
The coated film resistor of claim 4 wherein said silica is 5-10 weight percent of said coating.
Claim 9
Dependent Claim
15 words
The film resistor of claim 5 wherein the coatings is 1.5 to 2.5 mils thick.
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) | 1982-03-26 | 1982-09-25 | 1983-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-26 | 1986-09-25 | 1987-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-26 | 1990-09-25 | 1991-03-27 | $7700.00 | Window Closed / Lapsed |