Trw Limited

Kenneth M Merz

Howard E Shapiro

Richard L Wahlers

Laurence N Wesson

Cornelius Y Huang

A thick film temperature sensitive device and method of making the same, comprising the steps of applying to the surface of a substrate and firing a resistance material comprising a mixture of glass frit and particles containing palladium and iron. The mixture is fired in a non oxidizing, neutral, or reducing atmosphere at a temperature between 700.degree. C. and 1100.degree. C. at which the glass frit softens. When cooled, a device is provided with a glass film strongly bonded to the substrate and having dispersed therein conductive metal particles of an alloy of palladium and iron. The device provides a relatively high positive temperature coefficient of resistance, a relatively high resistivity, and a resistance to temperature characteristic which is highly linear, and can be processed by spiralling and terminated by the use of electroless plating. Further, the palladium and iron are present in the mixture in an amount having a total weight between about 15% and 65%, and the glass frit being present in an amount between 35% and 85% by weight.

Thick film temperature sensitive device and method and material for

A vitreous enamel resistor material comprising a mixture of a vitreous glass frit and fine particles of tin oxide (SnO.sub.2). An electrical resistor is made from the resistor material by applying the material to a substrate and firing the coated substrate to a temperature between about 850.degree. C. and 1150.degree. C. at which the glass melts. Upon cooling, the substrate has on the surface thereof, a film of the glass having the particles of the tin oxide embedded therein and dispersed therethroughout. The resistor material provides a resistor having a resistivity within a wide range and a low temperature coefficient of resistance.

Electrical resistor material, resistor made therefrom and method of

A vitreous enamel resistor material comprising a mixture of a vitreous glass frit and fine particles of tin oxide (SnO.sub.2). An electrical resistor is made from the resistor material by applying the material to a substrate and firing the coated substrate to a temperature at which the glass melts. The tin oxide is preferably heat treated prior to mixing with the glass frit. Upon cooling, the substrate has on the surface thereof, a film of the glass having the particles of the tin oxide embedded therein and dispersed therethroughout. The resistor material provides a resistor having a wide range of resistivity and a low temperature coefficient of resistance.

A liquid level sensing means for providing a continuous indication of liquid level or liquid content of a container comprising an elongated light conducting element adapted for being received into a liquid having first and second ends and a surface which provides an interface with the liquid for measuring liquid levels between the ends of the conducting element. A source provides radiation to the conducting element at one end, and detecting means for sensing radiation transmitted by the conducting element is positioned at the end of the conducting element opposite to the source of radiation and provides an output signal responsive to the intensity of the sensed radiation. The conducting element is transparent to radiation, has an index of refraction which is greater than that of the liquid which is to have its level measured, and has contoured regions on at least a portion of its surface. The contoured regions have an inclination which provides radiation impinging thereon from the source with an angle of incidence which is not greater that the critical angle characterizing the liquid interfaced regions, and which angle is greater than the critical angle characterizing regions which are not interfaced with the liquid, whereby the liquid interfaced regions refract radiation and the regions which are not interfaced with the liquid reflect radiation impinging thereon from the source, and the intensity of the radiation received by the detecting means is a function releated to the level of liquid between the ends of the conducting element.

Liquid level sensing means

A signal transducing unit which is compact and can be calibrated from outside its housing to provide zero and span adjustments after assembly with the components secured within its housing. The device has a pair of first and second elements movable with respect to each other and each having first and second ends and a conductive path, and the conductive paths of the elements electrically contact each other at a location which is displaced along their paths with the relative movement of the elements. Positioning means retains the elements for relative movement, while actuating means displaceable for moving and positioning the first element with respect to the first element controls the contact location of the elements. Adjusting means controllably sets the positions of the elements with respect to each other for a given displacement of the actuating means for providing calibration, and connecting means electrically joins with the conductive paths of the first and second elements to provide an output signal determined by the position of one element with respect to the other.

Signal transducing unit

A vitreous enamel resistor material comprising a mixture of a glass frit, and fine particles of tin oxide (SnO.sub.2), a primary additive of particles of oxides of manganese, nickel, cobalt or zinc, and a supplemental additive of oxides of tantalum, niobium, tungsten or nickel. An electrical resistor is made from the resistor material by applying the material to a substrate and firing the coated substrate to a temperature at which the glass melts. The tin oxide may be heat treated prior to mixing the glass frit. Upon cooling, the substrate has on the surface thereof, a film of the glass having the particles of the mixture embedded therein and dispersed therethroughout. The resistor material provides a resistor having a wide range of resistivities and a low temperature coefficient of resistance.

A vitreous enamel resistor material comprising a mixture of a vitreous glass frit and fine particles of tantalum. The vitreous enamel resistor material may also include fine particles selected from titanium, boron, tantalum oxide (Ta.sub.2 O.sub.5), titanium oxide (TiO), barium oxide (BaO.sub.2), zirconium dioxide (ZrO.sub.2), tungsten trioxide (WO.sub.3), tantalum nitride (Ta.sub.2 N), titanium nitride (TiN), molybdenum disilicide (MoSi.sub.2), and magnesium silicate MgSiO.sub.3). An electrical resistor is made from the resistor material by applying the material to a substrate and firing the coated substrate to a temperature at which the glass melts. Upon cooling, the substrate has on a surface thereof a film of glass having the tantalum particles and particles of the additive material, if used, embedded therein and dispersed therethroughout.

Resistor material, resistor made therefrom and method of making the same

A vitreous enamel resistor material comprising a mixture of a vitreous glass frit and fine particles of tantalum nitride (Ta.sub.2 N). The vitreous enamel resistor material may also include fine particles selected from boron, tantalum, silicon, zirconium dioxide (ZrO.sub.2), and magnesium zirconate (MgZrO.sub.3). An electrical resistor is made from the resistor material by applying the material to a substrate and firing the coated substrate to a temperature at which the glass melts. Upon cooling, the substrate has on a surface thereof a film of glass having the tantalum nitride particles and particles of the additive material, if used, embedded therein and dispersed therethroughout.

A vitreous enamel resistor material comprising a mixture of vitreous glass frit and fine particles of a mixture of zinc oxide (ZnO) and a material which will provide either lithium, tin, nickel, aluminum, indium, titanium, tantalum, zinc, gallium, vanadium, tungsten, or molybdenum. An electrical resistor is made from the resistor material by applying the material to a substrate and firing the coated substrate to a temperature at which the glass melts. Upon cooling, the substrate has on a surface thereof a film of glass having the particles of the mixture embedded therein and dispersed therethroughout. The resistor material provides a resistor having a wide range of resistivities with a low temperature coefficient of resistance and a low voltage coefficient of resistance.

A material for a vitreous enamel electrical resistor includes a mixture of a glass frit and particles of nickel, iron and cobalt. The material is applied to a substrate and fired to melt the glass frit, and then cooled to form a layer of the glass with particles of an alloy of nickel, iron and cobalt embedded therein. The material provides a resistor having a high temperature coefficient of resistance and which can be self terminating.

Vitreous enamel material for electrical resistors and method of making

A vitreous enamel resistor material comprising a mixture of vitreous glass frit and fine particles of zinc oxide (ZnO). An electrical resistor is made from the resistor material by applying the material to a substrate and firing the coated substrate to a temperature at which the glass melts. Upon cooling, the substrate has on a surface thereof a film of glass having the zinc oxide particles embedded therein and dispersed therethroughout. The resistor material provides resistors having a wide range of resistivities with low temperature coefficients of resistance and low voltage coefficients of resistance.

A termination material for a vitreous enamel electrical resistor includes a mixture of a glass frit and particles of either molybdenum, tungsten, tantalum or titanium. The termination material is applied to a substrate and fired to melt the glass frit, and then cooled to form a layer of the glass with the metal particles embedded therein. The termination material may be applied to the substrate either before or after the resistance material is applied to the substrate and is particularly useful with vitreous enamel resistance materials which include either a mixture of tantalum nitride and tantalum, a mixture of tungsten carbide and tungsten, or an alloy of copper and nickel.

Termination for electrical resistor and method of making the same

A vitreous enamel resistor material comprising a mixture of a vitreous glass frit and fine particles of a mixture of tin oxide (SnO.sub.2) and tantalum oxide (Ta.sub.2 O.sub.5). An electrical resistor is made from the resistor material by applying the material to a substrate and firing the coated substrate to a temperature at which the glass melts. The oxide mixture may be heat treated prior to mixing with the glass frit. Upon cooling, the substrate has on the surface thereof a film of the glass having the particles of the oxides embedded therein and dispersed therethroughout. The resistor material provides a resistor having a high resistivity and a low temperature coefficient of resistance.

A vitreous enamel resistance material including a mixture of a vitreous glass frit and fine particles of a conductor which is an alloy of nickel and chromium. The conductor particles are present in the amount of 28 to 80% by weight. Up to 3% by weight of titanium and/or titanium nitride may be included in the resistance material to adjust the temperature coefficient of resistance of the material.

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Gladwyne, PA, United States of America

Kenneth M Merz