CA1166437A - Resistive element composition - Google Patents
Resistive element compositionInfo
- Publication number
- CA1166437A CA1166437A CA000379935A CA379935A CA1166437A CA 1166437 A CA1166437 A CA 1166437A CA 000379935 A CA000379935 A CA 000379935A CA 379935 A CA379935 A CA 379935A CA 1166437 A CA1166437 A CA 1166437A
- Authority
- CA
- Canada
- Prior art keywords
- range
- resistive element
- rich
- pyrochlore
- mixtures
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
- H01C7/06—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material including means to minimise changes in resistance with changes in temperature
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C17/00—Apparatus or processes specially adapted for manufacturing resistors
- H01C17/06—Apparatus or processes specially adapted for manufacturing resistors adapted for coating resistive material on a base
- H01C17/065—Apparatus or processes specially adapted for manufacturing resistors adapted for coating resistive material on a base by thick film techniques, e.g. serigraphy
- H01C17/06506—Precursor compositions therefor, e.g. pastes, inks, glass frits
- H01C17/06513—Precursor compositions therefor, e.g. pastes, inks, glass frits characterised by the resistive component
- H01C17/06533—Precursor compositions therefor, e.g. pastes, inks, glass frits characterised by the resistive component composed of oxides
- H01C17/0654—Oxides of the platinum group
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Manufacturing & Machinery (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Non-Adjustable Resistors (AREA)
- Conductive Materials (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A resistive element for use in electrical and electronic circuits features a composition having atleast one precious metal-containing pyrochlore of the formula:
A2 [32-xAx] 07-y wherein A is selected from a group consisting of Pb, Bi and mixtures thereof; B is selected from a group consist-ing of: Ru, Ir and mixtures thereof; wherein x is greater than zero, and is approximately equal to or less than 1.0; and wherein y is equal to or greater than zero, and is approximately equal to or less than one.
A resistive element for use in electrical and electronic circuits features a composition having atleast one precious metal-containing pyrochlore of the formula:
A2 [32-xAx] 07-y wherein A is selected from a group consisting of Pb, Bi and mixtures thereof; B is selected from a group consist-ing of: Ru, Ir and mixtures thereof; wherein x is greater than zero, and is approximately equal to or less than 1.0; and wherein y is equal to or greater than zero, and is approximately equal to or less than one.
Description
1 16643~
FIELD OF THE INVENTION
-The invention relates to electrical resistive elements of new composition which exhibit improved properties.
RELATED PATENTS
The following patents are a teaching relating to new pyro-chlore materials which can be used in this invention, and their synthesis.
~ .S. Patent No. 4,124,539 for "Pb2 ~M2 XPbx~ 07 y Compounds Wherein M is Ru; Ir or Mixtures Thereof, and Method of Preparation", to H.S. Horowitz; J.M. Longo; and 3~el I. Haberman, issued November 7, 1978.
U.S. Patent No. 4,203,871 for "Method of Making Lead and Bismuth Ruthenate and Iridate Pyrochlore Compounds", to H.S.
Horowitz; J.M. Longo; and J.T. Lewandowski, issued May 20, 1980.
U.S. Patent No. 4,129,525 for "Method of Making Lead-Rich and Bismuth-Rich Pyrochlore Compounds Using an Alkaline Medium", to H.S. Horowitz; J.M. Longo; and J.T. Lewandowski, issued December 12, 1978.
U.S. Patent No. 4,146,458 for "Electrochemical Device Having an Oxygen Electrode Containing a Pyrochlore Type Compound Electrocatalyst", to H.S. Horowitz; J.M. Longo; and Joel I.
Haberman, issued March 27, 1979.
U.S. Patent No. 4,163,706 for "Bi2 [M2 XBixl 07 y Compounds Wherein M is Ru, Ir or Mixtures Thereof, and Electro-chemical Devices Containing Same", to H.S. Horowitz; J.M. Longo;
and J.T. Lewandowski, issued August 7, 1979.
U.S. Patent No. 4,I92,780 for "Method of Making Lead-Rich and Bismuth-Rich Pyrochlore Compounds Using an Alkaline Medium and a Reaction Enhancing Potential", to H.S. Horowitz; J.M. Longo; and J.T. Lewandowski, issued March 11, 1980.
BACKGROUND O~ THE INVE~TION
FIELD OF THE INVENTION
-The invention relates to electrical resistive elements of new composition which exhibit improved properties.
RELATED PATENTS
The following patents are a teaching relating to new pyro-chlore materials which can be used in this invention, and their synthesis.
~ .S. Patent No. 4,124,539 for "Pb2 ~M2 XPbx~ 07 y Compounds Wherein M is Ru; Ir or Mixtures Thereof, and Method of Preparation", to H.S. Horowitz; J.M. Longo; and 3~el I. Haberman, issued November 7, 1978.
U.S. Patent No. 4,203,871 for "Method of Making Lead and Bismuth Ruthenate and Iridate Pyrochlore Compounds", to H.S.
Horowitz; J.M. Longo; and J.T. Lewandowski, issued May 20, 1980.
U.S. Patent No. 4,129,525 for "Method of Making Lead-Rich and Bismuth-Rich Pyrochlore Compounds Using an Alkaline Medium", to H.S. Horowitz; J.M. Longo; and J.T. Lewandowski, issued December 12, 1978.
U.S. Patent No. 4,146,458 for "Electrochemical Device Having an Oxygen Electrode Containing a Pyrochlore Type Compound Electrocatalyst", to H.S. Horowitz; J.M. Longo; and Joel I.
Haberman, issued March 27, 1979.
U.S. Patent No. 4,163,706 for "Bi2 [M2 XBixl 07 y Compounds Wherein M is Ru, Ir or Mixtures Thereof, and Electro-chemical Devices Containing Same", to H.S. Horowitz; J.M. Longo;
and J.T. Lewandowski, issued August 7, 1979.
U.S. Patent No. 4,I92,780 for "Method of Making Lead-Rich and Bismuth-Rich Pyrochlore Compounds Using an Alkaline Medium and a Reaction Enhancing Potential", to H.S. Horowitz; J.M. Longo; and J.T. Lewandowski, issued March 11, 1980.
BACKGROUND O~ THE INVE~TION
2 The polynary oxide compounds utilized in this
3 invention display the pyrochlore crystal structure which
4 have a ComPOsitiOn that is best described by the following general formula:
6 2 [ ~ 6 7 wherein A and B are metal cations. A detailed description 8 of this structure is given by A. F. Wells, Structural 9 Inorganic Chemistry, Fourth Edition, Clarenden Press, Oxford, (1975), p~ 209. Briefly, oxides of this type 11 display a face-centered cubic structure having a unit 12 cell dimension of about lOA. The B cations are octa-13 hedrally coordinated by oxygen anions (Q). The struc-14 tural framework is formed by a three-dimensional array of these corner shared octahedra, each sharing corners with 16 six others. This framework has the composition B206.
17 As Wells describes, this framework of octahedra is 18 "based on the diamond net, having large holes which con-19 tain the 0' and two A atoms which themselves form a cuprite-like net A20' interpenetrating the octahedral 21 framework". The octahedra are actually arranged in 22 tetrahedral clusters. These clusters of octahedra are 23 then tetrahedrally arranged so as to form the large 24 holes in the structure described by Wells. Each of these large holes may also be defined by four tetrahedrally 26 arranged puc~ered, hexagonal rings which are formed by 27 the corner shared octahedra. The A cations reside in 28 the center of these puckered hexagonal rings and are 29 coordinated by the six 0 anions which define the rings plus two more 0' cations at a slightly different distance.
31 These 0' anions reside at the center of the large holes 32 in the octahedral framework. It is the 0' anions which 33 may be partially or totally absent, leading to the gen-34 eral pyrochlore oxide formula A2B207 y where 0< y< 1.
Some precious metal-containing pyrochlores 36 are known to be useful in resistor element composi-37 tions~ See for example: Bouchard, ~.S. Patent `` 11~6437`
1 No. 3,583,931, issued June 8, 1971; Bouchard, U.S.
2 Patent No. 3r681,262, issued August 1, 1972; Van Loan, 3 U.S. Patent No. 3,682,840, issued August 8, 1972;
4 ~ouchard, U.S. Patent No. 3,896,055, issued July 22, 1975;
Carcia, U.S. Patent No. 3r974rlO7, issued August 10, 1976;
6 ~ouchardr U.S. Patent No. 3,960,778 issued June Ir 1976;
7 Langleyr U.S. Patent No. 3,951r672r issued April 20r 1976.
8 For certain precious metal-containing pyro-9 chlores, it has rather unexpectedly been found that sub-stitution of the cations on the A site such as Pb or Bi 11 for the cations on the B site such as Ru or Ir provides 12 new compositions that are useful as resistive elements_ 13 More surprisingly these lead-rich and bismuth-rich 14 pyrochlores have temperature coefficients of resistivity which vary uniformly as a function of the lead or bis-16 muth content and therefore provide an unparalleled method 17 to control the temperature coefficient of resistivity 18 (TCR). Especially important has been the discovery that 19 certain ones of these lead-rich and bismuth-rich pyro-chlore compositions have been discovered to further pro-21 vide a substantially constant resistivity over a wide 22 temperature range. Resistor elements comprised of 23 these compositions can function in temperature compen-24 sated circuitry.
In addition, the lead-rich and bismuth-rich 26 pyrochlore compositions of this invention have reduced 27 amounts of precious metal which provides an important 28 economic advantage. A weight reduction of more than 29 50~ for the precious metal content is possible for the resistive compositions of this invention. The particular 31 ease of preparing the inventive compositions as taught 32 in the following patents by Horowitz et al: U.S. Patent 33 No. 4,129,525, issuea December 12, 1978; U.S. Patent No.
34 4,146,458, issued March 27, 1979; U.S. Patent No. 4,163,706, issued August 7, 1979; U.S. Patent No. 4,192,780, issued 36 March 11, 1980; and U.S. Patent No. 4,203,871, issued 37 May 20, 1980, provide further reliabilities and economics 1 ~66~3~
1 o~er the prior art. The physical form of the product 2 from this synthesis approach produces a resistive com-3 position in a form which is ideally suited for its dis-4 persion in a non-conductive organic or inorganic binder, which can be essential in the fabrication of resistive 6 elements. Consequently, resistive elements comprising 7 one or more of the lead-rich or bismuth-rich pyrochlore 8 compounds, as set forth by this invention, provide sig-9 nificant advantages over the prior art compositions.
11 The invention pertains to a resistive element 12 for use in electrical and electronic circuits. The 13 resistive element comprises a composition having at least 14 one precious metal-containinq pyrochlore of the formula:
A2 ~B2 xAx~ 7 Y
16 wherein A is selected from a group consisting of Pb, Bi 17 and mixtures thereof; B is selected from a group con-18 sisting of: Ru, Ir and mixtures thereof; wherein x is 19 greater than zero, and is approximately equal to or less than 1.0; and wherein y is equal to or greater than 21 zero, and is approY.imately equal to or less than one.
22 Of those compositions which are preferred, A
23 is Pb, B is Ru, and x is chosen to have a range of 24 approximately 0.15 to 0.65. More particularly, x is chosen as approximately 0.40 for applications requiring 26 the lowest possible TCR.
27 It is an object of this invention to provide 28 an improved resistive element for use in electrical and 29 electronic circuits;
It is another object of this invention to 31 provide lead-rich or bismuth-rich pyrochlore, composi-32 tions for electrical and electronic resistive elements, 33 which are more economical than other similar resistive 34 elements;
It is still another object of this invention to 36 provide lead-rich or bismuth-rich pyrochlore compositions 37 which can be easily adjusted to precisely tailor the 1166437`
1 temperature coefficient o~ resistivity for use in electri-2 cal and electronic circuits, 3 These and other objects of the invention will 4 ~ecome more apparent and will be better understood with respect to the following detailed description consiaered 6 in conjunction with the accompanying drawings.
7 BRIEF DESCRIPTIO~ OF THE DRAWING_ 8 Figure 1 is a graph illustrating the resistivity 9 of various lead-rich pyrochlore compositions with respect to tem?erature.
11 Fi~ure 2 is a similar graph of resistivity as 12 that shown in Figure 1, for other and similar lead-rich 13 pyrochlore compositions extended over a wider temperature 14 range.
Figure 3 is a graph depicting the resistivity 16 of various bismuth-rich pyrochlore compositions with 17 respect to temperature.
18 DETAILrD DESCRIPTION OF THE INVENTION
_ 19 Generally speaking, this invention pertains to lead-rich and bismuth-rich pyrochlore compositions for use 21 in resistive elements of electrical or electronic cir-22 cuits. As defined herein, "resistive element" can refer 23 to resistive deposits of only a few microns, which can 24 be deposited upon integrated circuit chips or devices, or to a solid bar of resistive material which can be 26 hardwired into a circuit or electrical device.
27 The resistive element of the invention comprises 28 a composition of at least one metal-containing pyrochlore 29 of the formula:
A2 [B2_XAx] 07_y 31 wherein A is selected from a group consisting of Pb, Bi 32 and mixtures thereof; B is selected from a group consist-33 ing of: Ru, Ir and mixtures thereof; wherein x is 34 greater than zero, and is approximately equal to or less than 1.0i and wherein y is equal to or greater than zero, 36 and is approximately equal to or less than one.
37 Such composition can be made by the low 116643~
1 temperature alkaline medium synthesis technique described 2 in U.S. Patent No. 4,129,525.
3 The electracal resistivity versus temperature 4 behavior for "expanded" lead ruthenate, Pb2[Ru2_xPb~ 07 y in a range O< x ~0.98 is plotted in Figure 1. This data 6 represents the results of four probe measurements on 7 pressed powder samples in which a constant load was 8 maintained on the sample over the entire temperature g range. The resistivity measurements were extended to higher temperatures for several compositions in the 11 range 0< x <1.06, and the results are shown in Figure 2.
12 Comparison of the results shown in Figures 1 and 2 in-13 dicate good reproducibility for samples of the same or 14 similar composition~
It is evident from these results that the 16 expanded lead ruthenates are high conductivity materials 17 tlO 3 ohm-cm< P<10 1 ohm-cm) which exhibit a smooth 18 variation from a positive to a negative TCR as a function 19 Of increasing lead content. It is easy to "tailor" the temperature coefficient of resistivity of resistor com-21 positions based on Pb2~Ru2 XPbx~07 y by proper adjustment 22 Of Pb content. Moreover a composition with x=0.4 shows 23 a variation of resistivity with temperature which is 24 essentially zero (~ P/P = +1.4% for 80 K< T <400K). It is evident from Figure 3 that the expanded bismuth ruthenates 26 are also high conductivity materials and that they exhibit 27 a gradual increase in a small positive TCR as a function 28 of increasing bismuth content. The capability of simply 29 preparing resistive compositions with a positive, nega-tive or zero TCR by adjustment of the A/B ratio is very 31 advantageous in the manufacture of temperature compensated 32 electronic circuits. Current practice provides for only 33 limited adjustment of electrical properties of resistor 34 compositions based on precious metal-containing pyro-chlores of the type illustrated in Bouchard, U.S. Patent 36 No. 3,583,931, issued June 8, 1971; Van Loan, U.S.
37 Patent No. 3,682,840, issued August 8, 1972; Langley, 1 U.S. Patent No, 3,951,672, issued April 20, 1976, 2 through chemical substitution of elements which them-3 selves are often precious metals.
4 Having thus described the invention, what is desired to be protected by Letters Patent is presented 6 by the following appended claims.
6 2 [ ~ 6 7 wherein A and B are metal cations. A detailed description 8 of this structure is given by A. F. Wells, Structural 9 Inorganic Chemistry, Fourth Edition, Clarenden Press, Oxford, (1975), p~ 209. Briefly, oxides of this type 11 display a face-centered cubic structure having a unit 12 cell dimension of about lOA. The B cations are octa-13 hedrally coordinated by oxygen anions (Q). The struc-14 tural framework is formed by a three-dimensional array of these corner shared octahedra, each sharing corners with 16 six others. This framework has the composition B206.
17 As Wells describes, this framework of octahedra is 18 "based on the diamond net, having large holes which con-19 tain the 0' and two A atoms which themselves form a cuprite-like net A20' interpenetrating the octahedral 21 framework". The octahedra are actually arranged in 22 tetrahedral clusters. These clusters of octahedra are 23 then tetrahedrally arranged so as to form the large 24 holes in the structure described by Wells. Each of these large holes may also be defined by four tetrahedrally 26 arranged puc~ered, hexagonal rings which are formed by 27 the corner shared octahedra. The A cations reside in 28 the center of these puckered hexagonal rings and are 29 coordinated by the six 0 anions which define the rings plus two more 0' cations at a slightly different distance.
31 These 0' anions reside at the center of the large holes 32 in the octahedral framework. It is the 0' anions which 33 may be partially or totally absent, leading to the gen-34 eral pyrochlore oxide formula A2B207 y where 0< y< 1.
Some precious metal-containing pyrochlores 36 are known to be useful in resistor element composi-37 tions~ See for example: Bouchard, ~.S. Patent `` 11~6437`
1 No. 3,583,931, issued June 8, 1971; Bouchard, U.S.
2 Patent No. 3r681,262, issued August 1, 1972; Van Loan, 3 U.S. Patent No. 3,682,840, issued August 8, 1972;
4 ~ouchard, U.S. Patent No. 3,896,055, issued July 22, 1975;
Carcia, U.S. Patent No. 3r974rlO7, issued August 10, 1976;
6 ~ouchardr U.S. Patent No. 3,960,778 issued June Ir 1976;
7 Langleyr U.S. Patent No. 3,951r672r issued April 20r 1976.
8 For certain precious metal-containing pyro-9 chlores, it has rather unexpectedly been found that sub-stitution of the cations on the A site such as Pb or Bi 11 for the cations on the B site such as Ru or Ir provides 12 new compositions that are useful as resistive elements_ 13 More surprisingly these lead-rich and bismuth-rich 14 pyrochlores have temperature coefficients of resistivity which vary uniformly as a function of the lead or bis-16 muth content and therefore provide an unparalleled method 17 to control the temperature coefficient of resistivity 18 (TCR). Especially important has been the discovery that 19 certain ones of these lead-rich and bismuth-rich pyro-chlore compositions have been discovered to further pro-21 vide a substantially constant resistivity over a wide 22 temperature range. Resistor elements comprised of 23 these compositions can function in temperature compen-24 sated circuitry.
In addition, the lead-rich and bismuth-rich 26 pyrochlore compositions of this invention have reduced 27 amounts of precious metal which provides an important 28 economic advantage. A weight reduction of more than 29 50~ for the precious metal content is possible for the resistive compositions of this invention. The particular 31 ease of preparing the inventive compositions as taught 32 in the following patents by Horowitz et al: U.S. Patent 33 No. 4,129,525, issuea December 12, 1978; U.S. Patent No.
34 4,146,458, issued March 27, 1979; U.S. Patent No. 4,163,706, issued August 7, 1979; U.S. Patent No. 4,192,780, issued 36 March 11, 1980; and U.S. Patent No. 4,203,871, issued 37 May 20, 1980, provide further reliabilities and economics 1 ~66~3~
1 o~er the prior art. The physical form of the product 2 from this synthesis approach produces a resistive com-3 position in a form which is ideally suited for its dis-4 persion in a non-conductive organic or inorganic binder, which can be essential in the fabrication of resistive 6 elements. Consequently, resistive elements comprising 7 one or more of the lead-rich or bismuth-rich pyrochlore 8 compounds, as set forth by this invention, provide sig-9 nificant advantages over the prior art compositions.
11 The invention pertains to a resistive element 12 for use in electrical and electronic circuits. The 13 resistive element comprises a composition having at least 14 one precious metal-containinq pyrochlore of the formula:
A2 ~B2 xAx~ 7 Y
16 wherein A is selected from a group consisting of Pb, Bi 17 and mixtures thereof; B is selected from a group con-18 sisting of: Ru, Ir and mixtures thereof; wherein x is 19 greater than zero, and is approximately equal to or less than 1.0; and wherein y is equal to or greater than 21 zero, and is approY.imately equal to or less than one.
22 Of those compositions which are preferred, A
23 is Pb, B is Ru, and x is chosen to have a range of 24 approximately 0.15 to 0.65. More particularly, x is chosen as approximately 0.40 for applications requiring 26 the lowest possible TCR.
27 It is an object of this invention to provide 28 an improved resistive element for use in electrical and 29 electronic circuits;
It is another object of this invention to 31 provide lead-rich or bismuth-rich pyrochlore, composi-32 tions for electrical and electronic resistive elements, 33 which are more economical than other similar resistive 34 elements;
It is still another object of this invention to 36 provide lead-rich or bismuth-rich pyrochlore compositions 37 which can be easily adjusted to precisely tailor the 1166437`
1 temperature coefficient o~ resistivity for use in electri-2 cal and electronic circuits, 3 These and other objects of the invention will 4 ~ecome more apparent and will be better understood with respect to the following detailed description consiaered 6 in conjunction with the accompanying drawings.
7 BRIEF DESCRIPTIO~ OF THE DRAWING_ 8 Figure 1 is a graph illustrating the resistivity 9 of various lead-rich pyrochlore compositions with respect to tem?erature.
11 Fi~ure 2 is a similar graph of resistivity as 12 that shown in Figure 1, for other and similar lead-rich 13 pyrochlore compositions extended over a wider temperature 14 range.
Figure 3 is a graph depicting the resistivity 16 of various bismuth-rich pyrochlore compositions with 17 respect to temperature.
18 DETAILrD DESCRIPTION OF THE INVENTION
_ 19 Generally speaking, this invention pertains to lead-rich and bismuth-rich pyrochlore compositions for use 21 in resistive elements of electrical or electronic cir-22 cuits. As defined herein, "resistive element" can refer 23 to resistive deposits of only a few microns, which can 24 be deposited upon integrated circuit chips or devices, or to a solid bar of resistive material which can be 26 hardwired into a circuit or electrical device.
27 The resistive element of the invention comprises 28 a composition of at least one metal-containing pyrochlore 29 of the formula:
A2 [B2_XAx] 07_y 31 wherein A is selected from a group consisting of Pb, Bi 32 and mixtures thereof; B is selected from a group consist-33 ing of: Ru, Ir and mixtures thereof; wherein x is 34 greater than zero, and is approximately equal to or less than 1.0i and wherein y is equal to or greater than zero, 36 and is approximately equal to or less than one.
37 Such composition can be made by the low 116643~
1 temperature alkaline medium synthesis technique described 2 in U.S. Patent No. 4,129,525.
3 The electracal resistivity versus temperature 4 behavior for "expanded" lead ruthenate, Pb2[Ru2_xPb~ 07 y in a range O< x ~0.98 is plotted in Figure 1. This data 6 represents the results of four probe measurements on 7 pressed powder samples in which a constant load was 8 maintained on the sample over the entire temperature g range. The resistivity measurements were extended to higher temperatures for several compositions in the 11 range 0< x <1.06, and the results are shown in Figure 2.
12 Comparison of the results shown in Figures 1 and 2 in-13 dicate good reproducibility for samples of the same or 14 similar composition~
It is evident from these results that the 16 expanded lead ruthenates are high conductivity materials 17 tlO 3 ohm-cm< P<10 1 ohm-cm) which exhibit a smooth 18 variation from a positive to a negative TCR as a function 19 Of increasing lead content. It is easy to "tailor" the temperature coefficient of resistivity of resistor com-21 positions based on Pb2~Ru2 XPbx~07 y by proper adjustment 22 Of Pb content. Moreover a composition with x=0.4 shows 23 a variation of resistivity with temperature which is 24 essentially zero (~ P/P = +1.4% for 80 K< T <400K). It is evident from Figure 3 that the expanded bismuth ruthenates 26 are also high conductivity materials and that they exhibit 27 a gradual increase in a small positive TCR as a function 28 of increasing bismuth content. The capability of simply 29 preparing resistive compositions with a positive, nega-tive or zero TCR by adjustment of the A/B ratio is very 31 advantageous in the manufacture of temperature compensated 32 electronic circuits. Current practice provides for only 33 limited adjustment of electrical properties of resistor 34 compositions based on precious metal-containing pyro-chlores of the type illustrated in Bouchard, U.S. Patent 36 No. 3,583,931, issued June 8, 1971; Van Loan, U.S.
37 Patent No. 3,682,840, issued August 8, 1972; Langley, 1 U.S. Patent No, 3,951,672, issued April 20, 1976, 2 through chemical substitution of elements which them-3 selves are often precious metals.
4 Having thus described the invention, what is desired to be protected by Letters Patent is presented 6 by the following appended claims.
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A resistive element composition, which is suitable for use in electrical and electronic circuits and has a substantially constant resistivity over a temperature range from about 80°K to about 480°K, comprising:
(a) one or more pyrochlore materials represented by the formula:
(i) Pb2 [B2-XPBx]07-y where B is selected from ruthenium, iridium or mixtures thereof, x is in the range of 0.15 to 0.85 and y is in the range of 0 to 1;
(ii) Bi2[B2-xBix]07-y where B is selected from ruthenium, iridium or mixtures thereof, x is in the range of 0.05 to 0.4 and y is in the range of 0 to 1; and (b) at least one non-conductive binder, wherein the amount of Pb or Bi is optionally chosen with respect to B to obtain a desired coefficient of resistivity.
(a) one or more pyrochlore materials represented by the formula:
(i) Pb2 [B2-XPBx]07-y where B is selected from ruthenium, iridium or mixtures thereof, x is in the range of 0.15 to 0.85 and y is in the range of 0 to 1;
(ii) Bi2[B2-xBix]07-y where B is selected from ruthenium, iridium or mixtures thereof, x is in the range of 0.05 to 0.4 and y is in the range of 0 to 1; and (b) at least one non-conductive binder, wherein the amount of Pb or Bi is optionally chosen with respect to B to obtain a desired coefficient of resistivity.
2. The resistive element of claim 1 wherein x is in the range of 0.15 to 0.65 for the material represented by the formula designated by (i).
3. The resistive element of claim 2 wherein x is about 0.4 for the materials represented by both (i) and (ii).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US17650980A | 1980-08-08 | 1980-08-08 | |
| US176,509 | 1988-04-01 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1166437A true CA1166437A (en) | 1984-05-01 |
Family
ID=22644640
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000379935A Expired CA1166437A (en) | 1980-08-08 | 1981-06-17 | Resistive element composition |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0046053B1 (en) |
| JP (1) | JPS5755004A (en) |
| CA (1) | CA1166437A (en) |
| DE (1) | DE3172724D1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0650142B2 (en) * | 1984-01-25 | 1994-06-29 | 曙ブレーキ工業株式会社 | Vehicle drive control device |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2229122A (en) * | 1938-12-06 | 1941-01-21 | Jr Howell T Pershing | Metering spout |
| US3775347A (en) * | 1969-11-26 | 1973-11-27 | Du Pont | Compositions for making resistors comprising lead-containing polynary oxide |
| US3681262A (en) * | 1970-10-01 | 1972-08-01 | Du Pont | Compositions for making electrical elements containing pyrochlore-related oxides |
| US3974107A (en) * | 1974-03-27 | 1976-08-10 | E. I. Dupont De Nemours And Company | Resistors and compositions therefor |
| NL7711927A (en) * | 1977-10-31 | 1979-05-02 | Philips Nv | PROCEDURE FOR THE PREPARATION OF RESISTANCE MATERIAL AND RESISTANCE BODIES PREPARED THEREFORE. |
| US4176094A (en) * | 1977-12-02 | 1979-11-27 | Exxon Research & Engineering Co. | Method of making stoichiometric lead and bismuth pyrochlore compounds using an alkaline medium |
| US4225469A (en) * | 1978-11-01 | 1980-09-30 | Exxon Research & Engineering Co. | Method of making lead and bismuth pyrochlore compounds using an alkaline medium and at least one solid reactant source |
-
1981
- 1981-06-17 CA CA000379935A patent/CA1166437A/en not_active Expired
- 1981-08-05 EP EP19810303573 patent/EP0046053B1/en not_active Expired
- 1981-08-05 DE DE8181303573T patent/DE3172724D1/en not_active Expired
- 1981-08-07 JP JP56123944A patent/JPS5755004A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5755004A (en) | 1982-04-01 |
| EP0046053A3 (en) | 1983-04-27 |
| EP0046053A2 (en) | 1982-02-17 |
| DE3172724D1 (en) | 1985-11-28 |
| EP0046053B1 (en) | 1985-10-23 |
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