CA1103013A - Silver compositions - Google Patents
Silver compositionsInfo
- Publication number
- CA1103013A CA1103013A CA298,233A CA298233A CA1103013A CA 1103013 A CA1103013 A CA 1103013A CA 298233 A CA298233 A CA 298233A CA 1103013 A CA1103013 A CA 1103013A
- Authority
- CA
- Canada
- Prior art keywords
- silver
- glass
- pbf2
- compositions according
- compositions
- 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
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/14—Conductive material dispersed in non-conductive inorganic material
- H01B1/16—Conductive material dispersed in non-conductive inorganic material the conductive material comprising metals or alloys
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C17/00—Apparatus or processes specially adapted for manufacturing resistors
- H01C17/28—Apparatus or processes specially adapted for manufacturing resistors adapted for applying terminals
- H01C17/281—Apparatus or processes specially adapted for manufacturing resistors adapted for applying terminals by thick film techniques
- H01C17/283—Precursor compositions therefor, e.g. pastes, inks, glass frits
- H01C17/286—Precursor compositions therefor, e.g. pastes, inks, glass frits applied to TiO2 or titanate resistors
Abstract
ABSTRACT OF THE DISCLOSURE
Conductive silver compositions useful for producing in a single application step solderable metal coatings on titanate bodies especially semiconducting ceramic titanate bodies, the silver compositions comprising specific amounts of finely divided silver; boron, Ni3B, and/or certain nickel boride/phosphides, and a binder which is glass and/or PbF2.
These inorganic solids are dispersed in an inert liquid vehicle. Also these compositions fired on a dielectric substrate.
Conductive silver compositions useful for producing in a single application step solderable metal coatings on titanate bodies especially semiconducting ceramic titanate bodies, the silver compositions comprising specific amounts of finely divided silver; boron, Ni3B, and/or certain nickel boride/phosphides, and a binder which is glass and/or PbF2.
These inorganic solids are dispersed in an inert liquid vehicle. Also these compositions fired on a dielectric substrate.
Description
c ~la3~
This invention relates to electronics, and more particularly,to compositions useful for producing conduc-tor patterns adherent to substrates.
Conductor compositions which are applied to and fired on dielectric substrates (glass, glass~ceramic, and ceramic) usually comprise finely divided inorganic powders (e.g., metal particles and binder particles) and are commonly applied to substrates using so-called "thick film"
techniques, as a dispersion of these inorganic powders in an inert liquid medium or vehicle. Upon firing or sintering of the printed film, the metallic component of the composi-tion provides the functional (conductive) utility, while the inorganic binder (e.g.,glass, Bi2O3, etc.) bonds the metal particles to one another and to the substrate. Thick -ilm techniques are contrasted with thin film techniques which involve deposition of particles by evaporation or sputtering.
Thick film techniques are generally discussed in "Hand-book of Materials and Processes for Electronics", C. A. Harper, Editor, McGraw-Hill, N.Y., 1970. Chapter 12.
Thermistors are typically ceramic resistor bodies whose electrical resistance is temperature dependent.
Those whose resistances decrease with an increase in temperature are referred to as negative temperature l~C3~3 coefficient (NTC) thermistors, while those whose resistances increase with an increase in temperature are referred to as positive temperature coefficient (PTC) thermistors. Thermistor bodies are generally bodies of fired ceramic semiconductors. In the case of the NTC
thermistors, the latter are usually one or more metal oxides of a large group of metal oxides known to have semiconductive properties, some of the more commonly ~
used being the oxides of metals such as manganese, nickel, cobalt, iron, zinc, vanadium, zirconium, cerium, chromium and uranium. The PTC thermistor bodies generally are fired alkaline earth titanates which have been rendered semiconducting by the substitution of, for example, a small amount of a lanthanide (atomic number 57-71) or yttrium to yield compounds having the general formula Al_XBxTiO3 where A is Ba, Ca, and/or Sr and B is the substituted atom. Often the titanate is lanthanum-doped barium titanate, Bal_xLaxTiO3. Thermistors of both NTC
and PTC types must be provided with electrically conductive contacts to which circuit leads may be attached.
The conductive contacts or electrodes applied to thermistor bodies should be low resistance, essentially ohmic contacts, especially for PTC bodies. Silver compositions are widely known and used for providing fired-on conductive contacts or electrodes on ceramic objects. However, most commercial silver compositions do not provide low resistance, ohmic contacts when fired onto semiconductive PTC bodies, the reason apparently being that sufficient oxygen from the PTC body penetrates through the coating during firing to provide an oxidized i3 nonconducting or barrier layer between the fired-on coating or electrode and the semiconductive substrate. Short U.S.
Patent 3,547,835 (issued December 15, 1970) provided silver conductive compositions which minimized the penetration of oxygen from the semiconducting body into the silver coating during firing, by adding oertain amounts of aluminum to the silver composition. This material has been widely used commercially, but (as disclosed at col. 3, line 73 to col.
4, line 1 of U.S. 3,547,835) its fired coatings are not directly solderable. of course, leads must be soldered onto the electrode to form a functional device. Hence a silver coating free of aluminum is applied over the Ag~Al coating of Short to permit soldering.
Low resistance contacts for semiconducting ceramics are reviewed by J. W. Fleming et al., Ceramic Bulletin 55, 715-6 (1976) and H. M. Landis, Journal of Applied Physics 36, 2000-2001 (1965). A two-step process for makin~ contacts on semiconducting ceramics (flame-spray deposition of a layer of Al, then a layer of Cu) is disclosed in Kourtesis et al. U.S. Patent 3,676,211.
There is a need for a silver material which can be applied to a semiconducting body in a single step and fired to produce a low-ohmic electrode which is both adherent and solderable, eliminating the significant expense of applica-tion of a second silver layer over the initial fired silver coating.
This invention provides conductive silver .
:, ~a30l3 compositions of finely divided inorganic particles dispersed in an inert liquid vehicle, useful for producing in a single application step (followed by firing to sinter the inorganic particles) solderable electrodes adherent to ceramic titanate bodies. The compositions are especially useful on semiconducting titanate bodies.
The inorganic particles are at least sufficiently finely divided to pass through a 400 mesh screen and consist essentially of about, by ~leight, either (A)(l) 75-98 silver, preferably 75-80%, more preferably 76%; (2)
This invention relates to electronics, and more particularly,to compositions useful for producing conduc-tor patterns adherent to substrates.
Conductor compositions which are applied to and fired on dielectric substrates (glass, glass~ceramic, and ceramic) usually comprise finely divided inorganic powders (e.g., metal particles and binder particles) and are commonly applied to substrates using so-called "thick film"
techniques, as a dispersion of these inorganic powders in an inert liquid medium or vehicle. Upon firing or sintering of the printed film, the metallic component of the composi-tion provides the functional (conductive) utility, while the inorganic binder (e.g.,glass, Bi2O3, etc.) bonds the metal particles to one another and to the substrate. Thick -ilm techniques are contrasted with thin film techniques which involve deposition of particles by evaporation or sputtering.
Thick film techniques are generally discussed in "Hand-book of Materials and Processes for Electronics", C. A. Harper, Editor, McGraw-Hill, N.Y., 1970. Chapter 12.
Thermistors are typically ceramic resistor bodies whose electrical resistance is temperature dependent.
Those whose resistances decrease with an increase in temperature are referred to as negative temperature l~C3~3 coefficient (NTC) thermistors, while those whose resistances increase with an increase in temperature are referred to as positive temperature coefficient (PTC) thermistors. Thermistor bodies are generally bodies of fired ceramic semiconductors. In the case of the NTC
thermistors, the latter are usually one or more metal oxides of a large group of metal oxides known to have semiconductive properties, some of the more commonly ~
used being the oxides of metals such as manganese, nickel, cobalt, iron, zinc, vanadium, zirconium, cerium, chromium and uranium. The PTC thermistor bodies generally are fired alkaline earth titanates which have been rendered semiconducting by the substitution of, for example, a small amount of a lanthanide (atomic number 57-71) or yttrium to yield compounds having the general formula Al_XBxTiO3 where A is Ba, Ca, and/or Sr and B is the substituted atom. Often the titanate is lanthanum-doped barium titanate, Bal_xLaxTiO3. Thermistors of both NTC
and PTC types must be provided with electrically conductive contacts to which circuit leads may be attached.
The conductive contacts or electrodes applied to thermistor bodies should be low resistance, essentially ohmic contacts, especially for PTC bodies. Silver compositions are widely known and used for providing fired-on conductive contacts or electrodes on ceramic objects. However, most commercial silver compositions do not provide low resistance, ohmic contacts when fired onto semiconductive PTC bodies, the reason apparently being that sufficient oxygen from the PTC body penetrates through the coating during firing to provide an oxidized i3 nonconducting or barrier layer between the fired-on coating or electrode and the semiconductive substrate. Short U.S.
Patent 3,547,835 (issued December 15, 1970) provided silver conductive compositions which minimized the penetration of oxygen from the semiconducting body into the silver coating during firing, by adding oertain amounts of aluminum to the silver composition. This material has been widely used commercially, but (as disclosed at col. 3, line 73 to col.
4, line 1 of U.S. 3,547,835) its fired coatings are not directly solderable. of course, leads must be soldered onto the electrode to form a functional device. Hence a silver coating free of aluminum is applied over the Ag~Al coating of Short to permit soldering.
Low resistance contacts for semiconducting ceramics are reviewed by J. W. Fleming et al., Ceramic Bulletin 55, 715-6 (1976) and H. M. Landis, Journal of Applied Physics 36, 2000-2001 (1965). A two-step process for makin~ contacts on semiconducting ceramics (flame-spray deposition of a layer of Al, then a layer of Cu) is disclosed in Kourtesis et al. U.S. Patent 3,676,211.
There is a need for a silver material which can be applied to a semiconducting body in a single step and fired to produce a low-ohmic electrode which is both adherent and solderable, eliminating the significant expense of applica-tion of a second silver layer over the initial fired silver coating.
This invention provides conductive silver .
:, ~a30l3 compositions of finely divided inorganic particles dispersed in an inert liquid vehicle, useful for producing in a single application step (followed by firing to sinter the inorganic particles) solderable electrodes adherent to ceramic titanate bodies. The compositions are especially useful on semiconducting titanate bodies.
The inorganic particles are at least sufficiently finely divided to pass through a 400 mesh screen and consist essentially of about, by ~leight, either (A)(l) 75-98 silver, preferably 75-80%, more preferably 76%; (2)
2-6% boron, preferably 3-4%, more preferably 3%; and (3)
3-22% glass, PbF2 or mixtures thereof, preferably 10-21%, more preferably 21%; or (B)(l) 40-70% silver, preferably 50-60%, more preferably 56%; t2) 25-60% Ni3Bl xPX (where-in x is in the approximate range 0-0.6), preferably 25-40%, more preferably 30~; and (3) 3-22% glass,PbF2 or mixtures thereof, preferably 10-21%, more preferably 14%.
Mixtures of (A) and (B) may also be used. Component (3) in (A) and in (B) is preferably glass. Preferred composi-tions contain 60-80% inorganic particles and 20-40%
vehicle. Also of this invention are ceramic titanate ~odies having fired on and adherent thereto the above-described inorganic particles.
The compositions of this invention consist essentially of finely divided inorganic particles wherein silver serves as the conductive phase, boron or the above-described nickel borides serve to give the silver coating solderability and a resistance with low contact characteristics, and glass serves to increase adhesion ~1~3~3 to the substrate upon firing. PbF2 may be used with or in lieu of glass as a binder. When used, it is thought that PbF2 forms lead borate glass upon firing, by reacting with B203 produced on oxidation of boron. The relative pro-portions of the inorganic materials were selected to provide good conductivity, adherence and solderability. --Any conventional electronic glass may be used as the binder, as is well known to those skilled in the art, for example those of Larson & Short U.S. 2,822,279;
Short U.S. 2,819,170; etc. Preferred among glasses are borates and borosilicates, especially lead borates and borosilicates.
Patterson U.S. Patent 3,943,168, issued March 9, 1976, discloses, lnter alia, Ni3B compositions.
While the inorganic particles are generally sufficiently finely divided to pass through a 400 mesh screen, it is preferred that substantially all the particles have a largest dimension of 5 microns or less.
The compositions may, of course, be modified by the addition of other materials not affecting their beneficial characteristics.
The inorganic particles are dispersed in an inert liquid vehicle by mechanical mixing (e.g., on a roll mill) to form a paste-like composition. The latter is printed as "thick film" on conventional dielectric substrates in the conventional manner. Any inert liquid may be used as the vehicle. Any of various organic liquids with or without thickening and/or stabilizing ~3~13 agents and/or other common additives, may be used as the vehicle. Exemplary of the organic liquids which can be used are the aliphatic alcohols; esters of such alco-hols, for example, the acetates and propionates; ter-penes such as pine oil, terpineol and the like, solutions of resins such as the polymethacrylates of lower alcohols, or solutions of ethyl cellulose, in solvents such as pine oil and the monobutyl ether of ethylene glycol mono-acetate. The vehicle may contain or be composed of volatile liquids to promote fast setting after applica-tion to the substrate.
After drying to remove the vehicle, firing of the compositions of the present invention is carried out at temperatures and for times sufficient to sinter the inorganic materials and to produce conductor patterns adherent to the dielectric substrate. Firing is conducted at a temperature and for a duration sufficient to sinter the composition into an adherent, solderable coating which is electrically and physically continuous, ac-cording to principles well known to those skilled in the art. Firing may be conducted in a box or belt furnace, at a peak temperature in the range 550-625C., preferably at about 580C. The peak temperature is maintained for at least 2 minutes, preferably about 10 minutes. Although firing will normally be conducted in air, firing in an inert atmosphere (e.g. nitrogen, argon, etc.) is possible.
Soldering of the fired electrodes to attach leads is done conventionally, e.g. by fluxing and then dipping in the molten solder described below.
Although s~ecial advantage is obtained by firing these compositions on semiconducting ceramic substrates of substituted barium titanate, the compositions are useful for producing conductive patterns on other ceramic titanate substrates such as barium titanate itself, etc.
Examples The following examples and comparative showings are presented to illustrate this invention. Both herein and elsewhere in the specification and claims, all parts, percentages, ratios, etc., are by weight, unless other-wise specified. All screens are U.S. standard sieve scale.
The dielectric bodies used in this study were all semiconducting substituted barium titanate bodies and were of four different types. Each type had a different resistance when terminated by the multi-step state-of-the art techniques. The bodies had rated resistances of 1.1 ohm (18mm diameter by 2mm thick), 2 ohm (21mm diameter by lmm thick), 23 ohm (15mm diameter by 3mm thick), and 26 ohm (8mm diameter by 3mm thick), re-spectively.
The glass used in these experiments contained 81.3% PbO, 12.2% B2O3, 1.1% SiO2 and 5.4~ PbF2. The vehicle contained about 1 part ethyl cellulose and 9 parts terpineol. Silver, nickel boride, etc., are commercially available. Ni3Bl_XPx was prepared by melting appropriate quantities of starting materials in an induction furnace under an atmosphere of purified argon at 1200-1400C. in a high purity alumina crucible.
Peak temperature was generally 100-300C. above the _~_ 1~3013 temperature at which the chaxge was entirely molten.
Once the charge became molten, it was held at that temperature for about 10 minutes. In some preparations the starting materials were Ni, B and Ni2P; in others Ni, Ni3B and Ni2P were used. After the charge had cooled to an ingot, the latter was con~ninuted to a particle size such that the resultant powder passed through at least a 400 mesh screen.
All of the inorganic materials were finely divided, and had the surface areas indicated below:
glass, 0.97-1.27 m2/g.
silver, 0.75-1.35 m2/g.
boron, 13 m2/g.
Ni3B, 0.8-1.2 m2/g.
Ni3Bo.gpo.l~ /g 3 0.8P0.2 and Ni3Bo.4Po 6 used in Examples 14 and 15 were milled and passed through a 400 mesh screen.
- These inorganic powders in the proportions described below were dispersed in the above-described vehicle using a roll mill. The dispersions were then printed on one side of the substrate indicated below using a 165 mesh screen (substantially all of the surface was covered) and dried at 120C. in air for 10 minutes. The other side was similarly printed and dried, and the composite was heated at 325C. in air for 10 rninutes to burn out vehicle and then fired in air at 580C. for 10 minutes. All firing was done in pre- -heated box furnaces, but equivalent results were obtained by first drying at 120C. for 10 minutes and then firing in a belt furnace using a 60 minute cycle '~ , ' . ": - ' 3~:13 with 10 minutes at 580C. peak.
In each case the fired coatings were adherent to the substrate and could well withstand handling.
Leads were then attached to the fired electrodes by dipping for 10 seconds in a flux (20% tartaric acid/80%
ethylene glycol) held at 220C. and then dipping in 62~n/36Pb/2Ag solder held at 220C., 3 to 10 second dip.
Resistance of the soldered body was determined using a 2-probe digital volt/ohmmeter.
Table 1 illustrates silver/boron compositions with glass binder. Showing A and Examples 1-3 illustrate the importance of the amount of boron in this invention.
In Showing A (1.5~ boron), resistance was too high, as compared with Examples 1-3 using 3-6% boron. Showing B illustrates the affect of too much binder (28%), high resistance and only fair solderability. In Showing C
no binder was used resulting in no adhesion of silver coating to the substrate. In Examples 4, 5, 6, and 7 proportions of materials were varied.
In Table 2, Examples 8-12 illustrate the use of silver and various nickel borides. Showings D and E
produced inferior results absent silver and will have greater tendency to oxidize upon longer firing.
Showing F used no binder and was not solderable.
Examples 11 and 12 illustrate two phosphorus-substituted nickel borides.
In Table 3 (Examples 13-16) binder of PbF2 alone, or PbF2 and glass, was used.
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Mixtures of (A) and (B) may also be used. Component (3) in (A) and in (B) is preferably glass. Preferred composi-tions contain 60-80% inorganic particles and 20-40%
vehicle. Also of this invention are ceramic titanate ~odies having fired on and adherent thereto the above-described inorganic particles.
The compositions of this invention consist essentially of finely divided inorganic particles wherein silver serves as the conductive phase, boron or the above-described nickel borides serve to give the silver coating solderability and a resistance with low contact characteristics, and glass serves to increase adhesion ~1~3~3 to the substrate upon firing. PbF2 may be used with or in lieu of glass as a binder. When used, it is thought that PbF2 forms lead borate glass upon firing, by reacting with B203 produced on oxidation of boron. The relative pro-portions of the inorganic materials were selected to provide good conductivity, adherence and solderability. --Any conventional electronic glass may be used as the binder, as is well known to those skilled in the art, for example those of Larson & Short U.S. 2,822,279;
Short U.S. 2,819,170; etc. Preferred among glasses are borates and borosilicates, especially lead borates and borosilicates.
Patterson U.S. Patent 3,943,168, issued March 9, 1976, discloses, lnter alia, Ni3B compositions.
While the inorganic particles are generally sufficiently finely divided to pass through a 400 mesh screen, it is preferred that substantially all the particles have a largest dimension of 5 microns or less.
The compositions may, of course, be modified by the addition of other materials not affecting their beneficial characteristics.
The inorganic particles are dispersed in an inert liquid vehicle by mechanical mixing (e.g., on a roll mill) to form a paste-like composition. The latter is printed as "thick film" on conventional dielectric substrates in the conventional manner. Any inert liquid may be used as the vehicle. Any of various organic liquids with or without thickening and/or stabilizing ~3~13 agents and/or other common additives, may be used as the vehicle. Exemplary of the organic liquids which can be used are the aliphatic alcohols; esters of such alco-hols, for example, the acetates and propionates; ter-penes such as pine oil, terpineol and the like, solutions of resins such as the polymethacrylates of lower alcohols, or solutions of ethyl cellulose, in solvents such as pine oil and the monobutyl ether of ethylene glycol mono-acetate. The vehicle may contain or be composed of volatile liquids to promote fast setting after applica-tion to the substrate.
After drying to remove the vehicle, firing of the compositions of the present invention is carried out at temperatures and for times sufficient to sinter the inorganic materials and to produce conductor patterns adherent to the dielectric substrate. Firing is conducted at a temperature and for a duration sufficient to sinter the composition into an adherent, solderable coating which is electrically and physically continuous, ac-cording to principles well known to those skilled in the art. Firing may be conducted in a box or belt furnace, at a peak temperature in the range 550-625C., preferably at about 580C. The peak temperature is maintained for at least 2 minutes, preferably about 10 minutes. Although firing will normally be conducted in air, firing in an inert atmosphere (e.g. nitrogen, argon, etc.) is possible.
Soldering of the fired electrodes to attach leads is done conventionally, e.g. by fluxing and then dipping in the molten solder described below.
Although s~ecial advantage is obtained by firing these compositions on semiconducting ceramic substrates of substituted barium titanate, the compositions are useful for producing conductive patterns on other ceramic titanate substrates such as barium titanate itself, etc.
Examples The following examples and comparative showings are presented to illustrate this invention. Both herein and elsewhere in the specification and claims, all parts, percentages, ratios, etc., are by weight, unless other-wise specified. All screens are U.S. standard sieve scale.
The dielectric bodies used in this study were all semiconducting substituted barium titanate bodies and were of four different types. Each type had a different resistance when terminated by the multi-step state-of-the art techniques. The bodies had rated resistances of 1.1 ohm (18mm diameter by 2mm thick), 2 ohm (21mm diameter by lmm thick), 23 ohm (15mm diameter by 3mm thick), and 26 ohm (8mm diameter by 3mm thick), re-spectively.
The glass used in these experiments contained 81.3% PbO, 12.2% B2O3, 1.1% SiO2 and 5.4~ PbF2. The vehicle contained about 1 part ethyl cellulose and 9 parts terpineol. Silver, nickel boride, etc., are commercially available. Ni3Bl_XPx was prepared by melting appropriate quantities of starting materials in an induction furnace under an atmosphere of purified argon at 1200-1400C. in a high purity alumina crucible.
Peak temperature was generally 100-300C. above the _~_ 1~3013 temperature at which the chaxge was entirely molten.
Once the charge became molten, it was held at that temperature for about 10 minutes. In some preparations the starting materials were Ni, B and Ni2P; in others Ni, Ni3B and Ni2P were used. After the charge had cooled to an ingot, the latter was con~ninuted to a particle size such that the resultant powder passed through at least a 400 mesh screen.
All of the inorganic materials were finely divided, and had the surface areas indicated below:
glass, 0.97-1.27 m2/g.
silver, 0.75-1.35 m2/g.
boron, 13 m2/g.
Ni3B, 0.8-1.2 m2/g.
Ni3Bo.gpo.l~ /g 3 0.8P0.2 and Ni3Bo.4Po 6 used in Examples 14 and 15 were milled and passed through a 400 mesh screen.
- These inorganic powders in the proportions described below were dispersed in the above-described vehicle using a roll mill. The dispersions were then printed on one side of the substrate indicated below using a 165 mesh screen (substantially all of the surface was covered) and dried at 120C. in air for 10 minutes. The other side was similarly printed and dried, and the composite was heated at 325C. in air for 10 rninutes to burn out vehicle and then fired in air at 580C. for 10 minutes. All firing was done in pre- -heated box furnaces, but equivalent results were obtained by first drying at 120C. for 10 minutes and then firing in a belt furnace using a 60 minute cycle '~ , ' . ": - ' 3~:13 with 10 minutes at 580C. peak.
In each case the fired coatings were adherent to the substrate and could well withstand handling.
Leads were then attached to the fired electrodes by dipping for 10 seconds in a flux (20% tartaric acid/80%
ethylene glycol) held at 220C. and then dipping in 62~n/36Pb/2Ag solder held at 220C., 3 to 10 second dip.
Resistance of the soldered body was determined using a 2-probe digital volt/ohmmeter.
Table 1 illustrates silver/boron compositions with glass binder. Showing A and Examples 1-3 illustrate the importance of the amount of boron in this invention.
In Showing A (1.5~ boron), resistance was too high, as compared with Examples 1-3 using 3-6% boron. Showing B illustrates the affect of too much binder (28%), high resistance and only fair solderability. In Showing C
no binder was used resulting in no adhesion of silver coating to the substrate. In Examples 4, 5, 6, and 7 proportions of materials were varied.
In Table 2, Examples 8-12 illustrate the use of silver and various nickel borides. Showings D and E
produced inferior results absent silver and will have greater tendency to oxidize upon longer firing.
Showing F used no binder and was not solderable.
Examples 11 and 12 illustrate two phosphorus-substituted nickel borides.
In Table 3 (Examples 13-16) binder of PbF2 alone, or PbF2 and glass, was used.
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Claims (13)
1. A conductive composition of finely divided inorganic particles of silver, borides and glass dispersed in a vehicle, useful for producing metal coatings on ceramic titanate bodies, characterized in that inorganic particles consisting essentially of about, by weight, (A) (1) 75-98% silver (2) 2-6% boron, and (3) 3-22% glass, PbF2, or mixtures thereof, or (B) (1) 40-70% silver, (2) 25-60% Ni3B1-xPx wherein x is in the approximate range 0-0.6, and (3) 3-22% glass, PbF2, or mixtures thereof or (C) mixtures of (A) and (B), said compositions producing in a single application step solderable metal coatings on ceramic titanate bodies.
2. Compositions according to Claim 1 wherein the inorganic particles consist essentially of (A).
3. Compositions according to Claim 2 wherein (A) (3) is glass.
4. Compositions according to Claim 2 wherein (A) (3) is PbF2.
5. Compositions according to Claim 2 wherein (A) consists essentially of (1) 75-80% silver, (2) 3-4% boron, and (3) 10-21% glass, PbF2 or mixtures thereof.
6. Compositions according to Claim 5 of (1) 76% silver, (2) 3% boron, and (3) 21% glass, PbF2 or mixtures thereof.
7. Compositions according to Claim 1 wherein the inorganic particles consist essentially of (B).
8. Compositions according to Claim 7 wherein (B) (3) is glass.
9. Compositions according to Claim 7 wherein (B) (3) is PbF2.
10. Compositions according to Claim 7 wherein (B) consists essentially of (1) 50-60% silver, (2) 25-40% said Ni3B1-xPx, (3) 10-21% glass, PbF2 or mixtures thereof.
11. Compositions according to Claim 10 consisting essentially of (1) 56% silver, (2) 30% said Ni3B1-xPx, and (3) 14% glass, PbF2, or mixtures thereof.
12. Compositions according to Claim 1 of 60-80 inorganic particles and 20-40% vehicle.
13. Ceramic titanate bodies having adherent thereto a sintered electrode of the composition of any of Claim 1, Claim 2 and Claim 7.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/775,274 US4101710A (en) | 1977-03-07 | 1977-03-07 | Silver compositions |
| US775,274 | 1977-03-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1103013A true CA1103013A (en) | 1981-06-16 |
Family
ID=25103891
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA298,233A Expired CA1103013A (en) | 1977-03-07 | 1978-03-06 | Silver compositions |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4101710A (en) |
| JP (1) | JPS53110097A (en) |
| CA (1) | CA1103013A (en) |
| DE (1) | DE2809818C3 (en) |
| FR (1) | FR2383507A1 (en) |
| GB (1) | GB1568504A (en) |
| IT (1) | IT1094178B (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4271236A (en) * | 1979-10-29 | 1981-06-02 | E. I. Du Pont De Nemours And Company | Air fireable end termination compositions for multilayer capacitors based on nickel borides |
| US4400310A (en) * | 1980-02-12 | 1983-08-23 | E. I. Du Pont De Nemours And Company | Thick film silver compositions for silver terminations for reduced barium titanate capacitors |
| IE52134B1 (en) * | 1980-07-31 | 1987-07-08 | Du Pont | Thick film conductor compositions |
| US4345955A (en) * | 1980-10-28 | 1982-08-24 | E. I. Du Pont De Nemours And Company | Process for manufacturing multilayer ceramic chip carrier modules |
| US4401767A (en) * | 1981-08-03 | 1983-08-30 | Johnson Matthey Inc. | Silver-filled glass |
| US4436785A (en) | 1982-03-08 | 1984-03-13 | Johnson Matthey Inc. | Silver-filled glass |
| US4459166A (en) * | 1982-03-08 | 1984-07-10 | Johnson Matthey Inc. | Method of bonding an electronic device to a ceramic substrate |
| US4846163A (en) * | 1987-08-24 | 1989-07-11 | Cooper Industries, Inc. | Method of sealing capacitor bushings |
| EP0749132A4 (en) * | 1994-03-04 | 1997-05-14 | Komatsu Mfg Co Ltd | Positive temperature coefficient thermistor and thermistor device using it |
| US5431718A (en) * | 1994-07-05 | 1995-07-11 | Motorola, Inc. | High adhesion, solderable, metallization materials |
| GB9518033D0 (en) * | 1995-09-05 | 1995-11-08 | Cookson Matthey Ceramics Plc | Composition |
| JP4136113B2 (en) * | 1998-09-18 | 2008-08-20 | Ｔｄｋ株式会社 | Chip-type laminated electronic components |
| US6217821B1 (en) * | 1999-06-02 | 2001-04-17 | E. I. Du Pont De Nemours And Company | Method of forming distortion-free circuits |
| JP3797281B2 (en) * | 2001-09-20 | 2006-07-12 | 株式会社村田製作所 | Conductive paste for terminal electrode of multilayer ceramic electronic component, method for manufacturing multilayer ceramic electronic component, multilayer ceramic electronic component |
| JP3636123B2 (en) * | 2001-09-20 | 2005-04-06 | 株式会社村田製作所 | Manufacturing method of multilayer ceramic electronic component and multilayer ceramic electronic component |
| WO2009052141A1 (en) * | 2007-10-18 | 2009-04-23 | E. I. Du Pont De Nemours And Company | Conductive compositions and processes for use in the manufacture of semiconductor devices |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3929674A (en) * | 1974-06-03 | 1975-12-30 | Du Pont | Boride-containing metallizations |
| US3943168A (en) * | 1974-11-13 | 1976-03-09 | E. I. Du Pont De Nemours And Company | Conductor compositions comprising nickel borides |
| US4122232A (en) * | 1975-04-21 | 1978-10-24 | Engelhard Minerals & Chemicals Corporation | Air firable base metal conductors |
| US3970590A (en) * | 1975-06-23 | 1976-07-20 | E. I. Du Pont De Nemours And Company | Gold conductor compositions |
-
1977
- 1977-03-07 US US05/775,274 patent/US4101710A/en not_active Expired - Lifetime
-
1978
- 1978-03-06 IT IT20917/78A patent/IT1094178B/en active
- 1978-03-06 GB GB8832/78A patent/GB1568504A/en not_active Expired
- 1978-03-06 CA CA298,233A patent/CA1103013A/en not_active Expired
- 1978-03-06 FR FR7806320A patent/FR2383507A1/en active Granted
- 1978-03-07 JP JP2508178A patent/JPS53110097A/en active Granted
- 1978-03-07 DE DE2809818A patent/DE2809818C3/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| IT7820917A0 (en) | 1978-03-06 |
| US4101710A (en) | 1978-07-18 |
| GB1568504A (en) | 1980-05-29 |
| JPS6115523B2 (en) | 1986-04-24 |
| FR2383507A1 (en) | 1978-10-06 |
| DE2809818B2 (en) | 1979-11-15 |
| DE2809818A1 (en) | 1978-09-14 |
| FR2383507B1 (en) | 1981-07-10 |
| JPS53110097A (en) | 1978-09-26 |
| DE2809818C3 (en) | 1980-07-31 |
| IT1094178B (en) | 1985-07-26 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |