US3865970A - Vacuum-tight electric leadthrough in an electric discharge tube - Google Patents

Vacuum-tight electric leadthrough in an electric discharge tube Download PDF

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Publication number
US3865970A
US3865970A US308767A US30876772A US3865970A US 3865970 A US3865970 A US 3865970A US 308767 A US308767 A US 308767A US 30876772 A US30876772 A US 30876772A US 3865970 A US3865970 A US 3865970A
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US
United States
Prior art keywords
indium
leadthrough
electric
hole
nickel
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 - Lifetime
Application number
US308767A
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English (en)
Inventor
Gerardus Arnoldus Her Vrijssen
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US Philips Corp
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US Philips Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
Priority to US515702A priority Critical patent/US3924792A/en
Application granted granted Critical
Publication of US3865970A publication Critical patent/US3865970A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C27/00—Joining pieces of glass to pieces of other inorganic material; Joining glass to glass other than by fusing
    • C03C27/06—Joining glass to glass by processes other than fusing
    • C03C27/08—Joining glass to glass by processes other than fusing with the aid of intervening metal
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C27/00—Joining pieces of glass to pieces of other inorganic material; Joining glass to glass other than by fusing
    • C03C27/04—Joining glass to metal by means of an interlayer
    • C03C27/042—Joining glass to metal by means of an interlayer consisting of a combination of materials selected from glass, glass-ceramic or ceramic material with metals, metal oxides or metal salts
    • C03C27/046—Joining glass to metal by means of an interlayer consisting of a combination of materials selected from glass, glass-ceramic or ceramic material with metals, metal oxides or metal salts of metals, metal oxides or metal salts only
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J5/00—Details relating to vessels or to leading-in conductors common to two or more basic types of discharge tubes or lamps
    • H01J5/32—Seals for leading-in conductors
    • H01J5/40—End-disc seals, e.g. flat header
    • H01J5/42—End-disc seals, e.g. flat header using intermediate part
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0033—Vacuum connection techniques applicable to discharge tubes and lamps
    • H01J2893/0034—Lamp bases

Definitions

  • This method is particularly suitable for use in leadthroughs for wall electrodes, as they occur in cathode-ray tubes and television camera tubes, in
  • the invention relates to a method of manufacturing a vacuum-tight electric leadthrough in an electric discharge tube, in which the vacuum-tight seal is obtained by filling the hole provided at the area of the leadthrough by means of a plug of indium-containing material.
  • the invention furthermore relates to a discharge tube comprising an electric leadthrough obtained according to said method.
  • German Patent Specification No. 1,917,674 a hole is drilled in the face plate ofa television camera tube after which a layer of tin oxide which extends at least partly into the wall hole is provided on the inside of the face plate. A plug of indium or another plastic metal is then pressed into the hole and synthetic resin is poured on the contact on the outside after which a steel mandril is pressed into the indium which mandril has to ensure the electric contact with the tin oxide layer via said plug of indium.
  • a hole is provided in the glass envelope of an electric discharge tube at the area of an electric leadthrough and thewall of said hole is covered with a thin layer of metal, after which a plug of indium or of an indiurn alloy is pressed into the hole and the assembly is then degassed in a vacuum space at ahigh temperature, the indium or the indium alloy melting, the thin metal layer dissolving and readily adhering to the wall of the hole upon cooling.
  • the method according to the invention has the following advantages over the known method.
  • the indium-containing material dissolves the thin metal layer and then adheres to the wall of the hole.
  • the metal layer itself has protected the surface from deposit of contaminations so that a rigid and even adhesion of the indiumcontaining material to the clean surface is ensured.
  • the whole wall of the hole for the leadthrough is to be covered with a metal layer
  • said metal layer is preferably provided chemically.
  • the metals which can be provided chemically such as nickel, cobalt, copper, gold and silver, or alloys thereof
  • nickel is preferably used in the method according to the invention since said metal can be treated in an easy manner.
  • the chemical provision of a'layer of nickel is known in literature as electroless nickel-plating.”
  • indium is a good electrical conductor, is extremely ductile, has a very low vapour pressure and readily adheres to clean glass.
  • the filling material for the hole of the leadthrough contains indium.
  • said filling material consists entirely of indium. Alloys of indium, in particular those of indium and one or more of the metals platinum, gold, silver, copper, tin, lead, gallium and nickel are also extremely suitable for this purpose, provided the composition of these alloys be such that a sufficient ductility, a low vapour pressure, a good adherence to the support and a sufficiently high melting temperature remain ensured.
  • composition of the indium alloy for an electric leadthrough according to the invention, to achieve an optimum for the conditions prevailing during operation in an electric discharge tube comprising such a leadthrough.
  • An important guide in the choice of said composition may be that which is known with respect tov indium alloys from phase diagrams.
  • a favourable construction is obtained in that, after producing the electric leadthrough, electrodes are provided on the inside of the envelope of the tube by means of vapour deposition, sputtering or chemically providing a thin layer of metaL preferabIy nickel.
  • a thin layer of nickel is also provided on the inner wall and/or outer wall of the envelope of the tube around the hole simultaneously with the wall of the hole for the leadthrough, the indium or the indium alloy subsequently provided in the hole flows laterally across the provided nickel layer at the high degassing temperature, haircracks and interruptions in the coating layer being formed around the hole during the coolings.
  • a good electric contact between the nickel layer present on the inside and/or on the outside of the envelope then is no longer certain. Decreasing the temperature does not provide a correct solution since, for an effective degassing of the material, a temperaturewhich is as high as possible is just desirable.
  • the solution to this problem is obtained according to a special embodiment of the invention by providing on the provided nickel layer a second layer which consists of a material which prevents an unrestricted lateral flow of the indium or the indium alloy.
  • Such a layer can be obtained in a simple manner by superficially oxidizing the nickel layer, for example, by heating in open air. This oxidation should of course be carried out before the filling is provided in the hole for the leadthrough.
  • gases may be liberated mainly from the glass and the nickel layer provided theron, which gases again reduce the oxide skin present on the nickel layer, as a result of which the effect in view is fully or partly lost.
  • the glass support and the nickel layer provided thereon is preferably degassed, in the method according to the invention, before the said nickel layer is superficially oxidized.
  • Themethod according to the invention is preferably used in the manufacture of television camera tubes and cathode ray tubes in which the electrode systems for focusing and/or deflecting the electron beam are provided on the inside of the envelope.
  • the method according to the invention will be degassed by heating at 500C in a vacuum space and the indium 5 has dissolved the nickel layer 4 and has adhered to the wall 3 of the hole 2.
  • the glass wall 11 of the envelope of the tube serves as a support of the nickel layer 12 which extends over the inside and outside of the envelope as well as over the wall l5 of the hole for the leadthrough.
  • the nickel oxide layer 13 has formed. Aftercooling the hole is filled with an indium alloy 14 containing 5 percent of tin.
  • FIG. 4 again shows the cross-section of the electric leadthrough of FIG. 3 after the material has been degassed by heating at 500C in a vacuum space for 60 to 90 minutes and the indium alloy 14 has dissolved the oxide layer 13 and the nickel 12 present in the hole and has adhered to the wall 15 of the hole.
  • FIGS; land 2 are cross-sectional views not to scale through the axis of the hole of an electric leadthrough in the last two successive stages of the method according to the invention
  • FIGS. 3 and 4 are cross-sectional views likewise not drawn to scale of an electric leadthrough in the last two successive stages of the method according to the invention in which a superficial oxidation of the nickel layer has previously taken place.
  • FIG. 5 is a perspective view partly broken away and not drawn to scale of a part of a television camera tube provided with electric leadthroughs obtained according to the method as described with reference to FIGS. 3 and 4'.
  • a hole 2 having a diameter of 0.5 mm is provided in the 1 mm thick'glass wall'l of the envelope of the tube by means of sandblasting.
  • the wall 3 of the hole is electroless nickelplated with a nickel layer 4 of 0.1 pm thick, after which the hole is filled with an indium plug 5.
  • FIG. 2 again shows the cross-section of the electric leadthrough of FIG. 1 after the material has been dewhich the indium alloy flows at l6, depends upon the degassing temperature, the degassing time, the thickness of the oxide layer 13 and the thickness of the nickel layer 12.
  • FIG. 5 shows a part of a television .camera tube.
  • the glass wall 21 of the envelope of the tube has a thickness of 1 mm and serves as a support of the.electroless nickel layer 22 which again has an oxide'layer 23.
  • a plug 24 consisting of an alloy of percent indium and 5 percent silver is present in a hole of 0.5 mm crosssection and makes an electric contact between the connection strip 25 present on the outside of the envelope and the electrode 26 provided on the inside.
  • Electrode 27 is connected to strip 29 via leadthrough 28 in an analogous manner.
  • the leadthrough pins 30 serve for the supply and control of the electron gun not shown in the drawing.
  • An electric discharge tube comprising at least one electric leadthrough, comprising a leadthrough hole and a plug that is disposed in said hole and is thermally bonded at the wall of said hole, said plug consisting essentially of an alloy of indium and at least one of platinum, gold, silver, copper, lead, tin, gallium, nickel, and
  • An electric discharge tube as claimed in claim 1, comprising a nickel layer that is disposed on at least one of the inside and outside surfaces of the envelope and is substantially free of an oxide layer, wherein said plug-electrically contacts said nickel layer.
  • An electric discharge tube as claimed in claim 1, comprising a nickel layer that is disposed on at least one of the inside and outside surfaces of the envelope and comprises an oxide layer, at the exposed surface thereof, wherein said plug electrically contacts said

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
  • Gas-Filled Discharge Tubes (AREA)
  • Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
US308767A 1971-12-07 1972-11-22 Vacuum-tight electric leadthrough in an electric discharge tube Expired - Lifetime US3865970A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US515702A US3924792A (en) 1971-12-07 1974-10-17 Method of manufacturing a vacuum-tight electric leadthrough in an electric discharge tube

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL7116765A NL7116765A (OSRAM) 1971-12-07 1971-12-07

Publications (1)

Publication Number Publication Date
US3865970A true US3865970A (en) 1975-02-11

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ID=19814631

Family Applications (1)

Application Number Title Priority Date Filing Date
US308767A Expired - Lifetime US3865970A (en) 1971-12-07 1972-11-22 Vacuum-tight electric leadthrough in an electric discharge tube

Country Status (10)

Country Link
US (1) US3865970A (OSRAM)
JP (1) JPS5330305B2 (OSRAM)
AU (1) AU469065B2 (OSRAM)
BE (1) BE792315A (OSRAM)
CA (1) CA986169A (OSRAM)
DE (1) DE2258159C2 (OSRAM)
FR (1) FR2162544B1 (OSRAM)
GB (1) GB1365796A (OSRAM)
IT (1) IT975944B (OSRAM)
NL (1) NL7116765A (OSRAM)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4278912A (en) * 1978-06-24 1981-07-14 U.S. Philips Corporation Electric discharge tube having a glass-sealed electric leadthrough and method of manufacturing such an electric leadthrough
US4727633A (en) * 1985-08-08 1988-03-01 Tektronix, Inc. Method of securing metallic members together

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2746140A (en) * 1951-07-09 1956-05-22 Georgia Tech Res Inst Method of soldering to thin metallic films and to non-metallic substances
US3147053A (en) * 1960-05-19 1964-09-01 Rca Corp Method of sealing vacuum tubes
US3246386A (en) * 1962-01-26 1966-04-19 Corning Glass Works Electrical connected component and method
US3675062A (en) * 1966-02-11 1972-07-04 Fernseh Gmbh Method and apparatus for connecting to a nesa layer

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2746140A (en) * 1951-07-09 1956-05-22 Georgia Tech Res Inst Method of soldering to thin metallic films and to non-metallic substances
US3147053A (en) * 1960-05-19 1964-09-01 Rca Corp Method of sealing vacuum tubes
US3246386A (en) * 1962-01-26 1966-04-19 Corning Glass Works Electrical connected component and method
US3675062A (en) * 1966-02-11 1972-07-04 Fernseh Gmbh Method and apparatus for connecting to a nesa layer

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4278912A (en) * 1978-06-24 1981-07-14 U.S. Philips Corporation Electric discharge tube having a glass-sealed electric leadthrough and method of manufacturing such an electric leadthrough
US4727633A (en) * 1985-08-08 1988-03-01 Tektronix, Inc. Method of securing metallic members together

Also Published As

Publication number Publication date
DE2258159A1 (de) 1973-06-14
DE2258159C2 (de) 1983-03-03
FR2162544A1 (OSRAM) 1973-07-20
FR2162544B1 (OSRAM) 1977-12-23
AU469065B2 (en) 1976-02-05
CA986169A (en) 1976-03-23
GB1365796A (en) 1974-09-04
JPS4866366A (OSRAM) 1973-09-11
BE792315A (fr) 1973-06-05
AU4964972A (en) 1974-06-06
NL7116765A (OSRAM) 1973-06-12
JPS5330305B2 (OSRAM) 1978-08-25
IT975944B (it) 1974-08-10

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