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US3680028A Expired / Lapsed US ⏱️ 0.0 years remaining

Vertical resistor

Assignee: Motorola Solutions Inc
•
Filing: 1971-04-02
•
Granted: 1972-07-25
•
Expires: 1991-04-02
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Abstract

Abstract There is disclosed a high valued vertical resistor whose high value is a result of contacting the resistive film through pinholes in an insulating film on top of the resistive film. The value is controlled by the areal density of pinholes through the thin overlaying insulating film such that the higher the areal density the lower the resistance value for the particular resistor. The resistor is completed by providing a metal layer over the pinholed film such that the metal extends through the pinholes to the resistive layer making contact thereto at a multiplicity of points. The number and size of the contacts made to the resistive layer as well as the resistivity and thickness of the resistive layer controls the total resistance value of the resistor. The holes in the thin insulating film are formed and the hole size and number controlled by one of three methods involving the use of opaque particles, metal particles and porous photoresists as masks for etching the thin insulating film. In one embodiment metallization fills the pinholes in the thin insulating layer so as to provide a multiplicity of contacts to the resistive layer which are spaced and insulated one from another. The structure in this case can be used as a sensing device for determining a planar contact area of an electrically conducting structure contiguous to the top surface of the resistor, the contact area varying in an inverse manner with the resistance of the resistor. The structure fabricated without continuous overlaying metallization can also be used as a sensing device for sensing the contact area of a resilient structure having a conductive film on the outside thereof. The greatest utility of the vertical resistor thus formed is in electrical circuits in which a high but accurate resistive value for the resistor must be obtained. The resistance value of the resistor is provided by altering the areal density of the pinholes in the thin insulating film.

Inventors

  • 👤 James R Black
  • 👤 Harold S Gurev

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 12:32
CPC Classifications
H; H01; H01C; H01C1/00; H01C1/14; H01C17/00; H01C17/22

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 134 words
A vertical resistor comprising: a conductive substrate having an upper surface; a resistive film positioned on said upper surface; an insulating film positioned on said resistive film, said insulating film being formed with a multiplicity of apertures for exposing spaced portions of said resistive film therethrough; and contacting means positioned on top of said insulating film and extending into at least a plurality of said apertures so as to contact an equal plurality of those portions of said resistive film exposed by said plurality of apertures, the resistance value of the resistor being proportional in an inverse manner to the areal density of said plurality of apertures containing said contacting means and the resistance value of said insulating film, whereby the effective resistivity of said resistive film is augmented by said multiple contacting means.
Claim 2
Dependent Claim 134 words
A vertical resistor comprising: a conductive substrate having an upper surface; a resistive film positioned on said upper surface; an insulating film positioned on said resistive film, said insulating film being formed with a multiplicity of apertures for exposing spaced portions of said resistive film therethrough; and contacting means positioned on top of said insulating film and extending into at least a plurality of said apertures so as to contact an equal plurality of those portions of said resistive film exposed by said plurality of apertures, the resistance value of the resistor being proportional in an inverse manner to the areal density of said plurality of apertures containing said contacting means and the resistance value of said insulating film, whereby the effective resistivity of said resistive film is augmented by said multiple contacting means.
Claim 3
Dependent Claim 26 words
The resistor as recited in claim 1 wherein said resistive film is selected from the group consisting of cermets, nickel-chromium alloys, cobalt-chromium alloys, and nitrogen-rich tantalum.
Claim 4
Dependent Claim 25 words
The resistor as recited in claim 1 wherein said resistive film is an Al-Al2O3 cermet having a resistivity of between 103 and 104 ohm centimeters.
Claim 5
Dependent Claim 64 words
The resistor as recited in claim 1 wherein the resistance value of the resistor is given by: R Rho t/A where R is the resistance in ohms Rho is the effective resistivity of the resistive film in the completed device, t is the thickness of the resistive film in centimeters, A is the total contact area on the resistive film exposed through said apertures.
Claim 6
Dependent Claim 21 words
The resistor as recited in claim 1 wherein said resistive film as a thickness on the order of 10 4 centimeters.
Claim 7
Dependent Claim 18 words
The resistor as recited in claim 1 wherein the diameters of said apertures are in the sub-micron range.
Claim 8
Dependent Claim 52 words
The resistor as recIted in claim 1, wherein said contacting means is positioned on top of a portion of said insulating film and extends into a portion of said apertures, whereby the area of said contacting means is proportional to the value of resistance measured between said contacting means and said substrate.
Claim 9
Dependent Claim 59 words
In combination: a conductive substrate having an upper surface; a resistive film positioned on said upper surface; an insulating layer positioned on said resistive film; said layer being provided with a multiplicity of apertures for exposing spaced portions of said resistive film therethrough; and conductive means filling a plurality of said apertures and making electrical contact with said substrate.
Claim 10
Dependent Claim 59 words
In combination: a conductive substrate having an upper surface; a resistive film positioned on said upper surface; an insulating layer positioned on said resistive film; said layer being provided with a multiplicity of apertures for exposing spaced portions of said resistive film therethrough; and conductive means filling a plurality of said apertures and making electrical contact with said substrate.
Claim 11
Dependent Claim 43 words
In combination: a conductive substrate having a first surface; a resistive film positioned on said first surface; and an insulating layer positioned on said resistive film and being provided with a multiplicity of apertures for exposing spaced portions of said resistive film therethrough.
Claim 12
Dependent Claim 43 words
In combination: a conductive substrate having a first surface; a resistive film positioned on said first surface; and an insulating layer positioned on said resistive film and being provided with a multiplicity of apertures for exposing spaced portions of said resistive film therethrough.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-07-25 1976-01-24 1976-07-25 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-07-25 1980-01-24 1980-07-25 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-07-25 1984-01-24 1984-07-25 $7700.00 Window Closed / Lapsed

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