Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K3/00—Apparatus or processes for manufacturing printed circuits
  • H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
  • H05K3/12—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns
  • H05K3/1241—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns by ink-jet printing or drawing by dispensing
  • H05K3/125—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns by ink-jet printing or drawing by dispensing by ink-jet printing
• • 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
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/06—Surface treatment of glass, not in the form of fibres or filaments, by coating with metals
  • C03C17/10—Surface treatment of glass, not in the form of fibres or filaments, by coating with metals by deposition from the liquid phase
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M1/00—Inking and printing with a printer's forme
  • B41M1/12—Stencil printing; Silk-screen printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M1/00—Inking and printing with a printer's forme
  • B41M1/26—Printing on other surfaces than ordinary paper
  • B41M1/34—Printing on other surfaces than ordinary paper on glass or ceramic surfaces
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M7/00—After-treatment of prints, e.g. heating, irradiating, setting of the ink, protection of the printed stock
  • B41M7/009—After-treatment of prints, e.g. heating, irradiating, setting of the ink, protection of the printed stock using thermal means, e.g. infrared radiation, heat
• • 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
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
  • C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a 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
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
  • C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal
  • C03C17/3602—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer
  • C03C17/3644—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer the metal being silver
• • 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
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
  • C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal
  • C03C17/3602—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer
  • C03C17/3668—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer the multilayer coating having electrical properties
  • C03C17/3673—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer the multilayer coating having electrical properties specially adapted for use in heating devices for rear window of vehicles
• • 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
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K1/00—Printed circuits
  • H05K1/02—Details
  • H05K1/03—Use of materials for the substrate
  • H05K1/0306—Inorganic insulating substrates, e.g. ceramic, glass
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K3/00—Apparatus or processes for manufacturing printed circuits
  • H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
  • H05K3/12—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns
  • H05K3/1216—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns by screen printing or stencil printing
  • H05K3/1225—Screens or stencils; Holders therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M3/00—Printing processes to produce particular kinds of printed work, e.g. patterns
  • B41M3/008—Sequential or multiple printing, e.g. on previously printed background; Mirror printing; Recto-verso printing; using a combination of different printing techniques; Printing of patterns visible in reflection and by transparency; by superposing printed artifacts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/0041—Digital printing on surfaces other than ordinary paper
  • B41M5/007—Digital printing on surfaces other than ordinary paper on glass, ceramic, tiles, concrete, stones, etc.
• • 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
  • C03C2217/00—Coatings on glass
  • C03C2217/20—Materials for coating a single layer on glass
  • C03C2217/25—Metals
  • C03C2217/251—Al, Cu, Mg or noble metals
  • C03C2217/254—Noble metals
  • C03C2217/256—Ag
• • 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
  • C03C2218/00—Methods for coating glass
  • C03C2218/10—Deposition methods
  • C03C2218/11—Deposition methods from solutions or suspensions
  • C03C2218/119—Deposition methods from solutions or suspensions by printing

Definitions

• the present invention relates to the field of printing electrically conductive patterns, in particular based on silver, on glazing.
• Electrically conductive patterns such as heating wires, antennas or other sensors present in automotive glazing are made from a conductive paste, for example silver paste screen printed on a sheet of glass, and are connected to a system power supply via connectors soldered to conductive paste.
• the connectors are soldered in certain well-defined areas of the glazing and the alloys currently used to make these solders are lead-free alloys, for example based on silver, tin and copper. Glazing fitted with such electrically conductive devices must, in order to be able to be placed on the market and accepted by automobile manufacturers, successfully pass increasingly stringent resistance tests.
• the alloys used for the welds must in particular meet the criteria imposed by the TCT test (or “temperature cycling test”).
• the objective of this test is to determine whether the glazing, once equipped with the electrical functions, can withstand successive and rapid rises and falls in temperature, without being weakened.
• These tests were developed in order to accelerate the effects which would be caused by the differences in thermal behavior of the various components of the system.
• New test imposes temperature variations between -40 ° C and + 105 ° C, therefore over a larger variation range than the previous tests which were limited to 90 ° C.
• the number of cycles has also been modified since it went from 10 cycles to a minimum of 60 cycles.
• the new TCT conditions also require that these temperature variations be carried out under a voltage of 14 V during the temperature rise phases, which leads to additional heating and corresponds to local temperatures which can go up to approximately 120 ° C. .
• connection or welding zones are generally made at the level of the collector strips (also called “bus bars” in English terminology) located on either side of the heating network, in the lateral parts of the glazing, but can also be done in more central parts.
• a screen printing screen comprising a main screen and on a zone, located in the central part, at least one secondary screen fixed on one face. of said main screen, the mesh of the secondary screen being wider than the mesh of the main screen in said central part, and the mesh of the secondary screen forming with the mesh of the main screen an angle of between 1 and 89 °.
• a screen printing screen comprising a main screen and on a zone, located in the central part, at least one secondary screen fixed on one face. of said main screen, the mesh of the secondary screen being wider than the mesh of the main screen in said central part, and the mesh of the secondary screen forming with the mesh of the main screen an angle of between 1 and 89 °.
• this solution is not devoid of drawbacks, in particular in that it does not also make it possible to obtain an extra thickness in certain specific areas of the side parts. It also does not allow the thickness of the electrically conductive tracks in the weld areas and in the other areas to be adjusted completely independently. It is thus not always possible to achieve the desired thicknesses in the weld zones while respecting the specifications in terms of network resistance.
• the object of the invention is to obviate these drawbacks by proposing a process which makes it possible at a lower cost to obtain a glazing in which thick electrically conductive patterns can be produced in certain zones of the central part and in certain zones of the lateral parts.
• the subject of the invention is a process for obtaining a glazing comprising a sheet of glass coated on one of its faces with electrically conductive patterns having in at least one zone, called the excess thickness zone, a thickness greater than in the other zones, said method comprising the deposition by screen printing of a first electroconductive layer forming patterns on one face of said sheet of glass, then the deposition by a technique digital printing, in the or each zone of extra thickness, of a second electrically conductive layer on the first still wet layer, then a step of thermal baking treatment of the first and of the second layer.
• the glazing is in particular a glazing obtained or capable of being obtained by the process according to the invention.
• This glazing comprises a sheet of glass coated on one of its faces with electrically conductive patterns based on silver, exhibiting in at least one zone, called the extra thickness zone, a greater thickness than in the other zones.
• a zone of excess thickness is located in the central part, and another zone of excess thickness is located in only a part of each side part.
• the invention completes the screen printing step by a digital printing step, which produces an extra thickness in the desired areas, typically the weld areas or areas including the weld areas, which can be both in central areas as well as in areas. sides of the glazing.
• the electrically conductive patterns therefore comprise two superimposed layers (the first and the second layer), while they only include the first layer in the other zones.
• a glazing comprising patterns comprising electrically conductive tracks of small thickness, for example a network of heating wires, an alarm network, antennas or collecting bands, and welding zones of greater thickness which may be be located both in the central part and in the side parts of the glazing, for example welding areas for antenna buttons located in the central part and heating network welding zones located in the lateral part in contact with the collector strips.
• the areas of excess thickness are not necessarily limited to the weld areas.
• the invention also advantageously makes it possible to thicken certain zones of the collector strips, in particular near the weld zones, in particular to avoid undesirable heating.
• the extra thickness guarantees a robust weld without affecting the resistance of the heating wire network, which can be adjusted completely independently via the choice of the thickness of the first layer. It is thus possible to respect the specifications in terms of electrical resistance, which are specific to each model, by choosing the silver paste, the silkscreen screen, the wet thicknesses etc ..., and to apply the adequate allowance. to reach in the weld zones or in the zones including the weld zones, the thicknesses guaranteeing a good weld. The process is therefore very flexible in this regard.
• wet is meant that the first layer has not yet been dried, and therefore comprises a solvent. It is thus possible to proceed directly to the digital printing of the second layer without providing an additional drying station between the two deposition steps.
• a drying step is preferably implemented between the step of depositing the second layer and the step of heat treatment of cooking.
• the electrically conductive patterns preferably comprise electrically conductive tracks located in at least one side portion and in a central portion of the glazing, the zones of extra thickness being located in said central part and / or in at least one lateral part.
• the areas of extra thickness are located both in the central part and in at least one side part, and even in the side parts.
• the electrically conductive tracks located in the central part are in particular heating wires, alarm films and / or antennas.
• the electrically conductive tracks located in a lateral part, in particular in two opposite lateral parts, are in particular collector strips.
• the areas of extra thickness include weld zones, or even correspond to weld zones.
• the areas of extra thickness located in the central part are or include, for example, weld areas for antenna or alarm connection.
• the zones of extra thickness located in the lateral parts include, for example, weld zones for connecting a heating network. The latter are for example located on each of the collector bands.
• the solder areas are areas on which a connector can be soldered in order to electrically connect the electrically conductive patterns.
• the method can therefore also include an additional step of welding at least one connector over at least part of a zone of excess thickness.
• the welding is in particular carried out using a welding alloy.
• the connector is typically metallic, in particular steel containing chromium.
• the solder alloy is preferably lead-free, in particular based on tin, silver and copper.
• the glass sheet is typically soda-lime glass, but can be other types of glass, for example borosilicate or aluminosilicate. Its thickness is preferably between 0.7 and 6 mm, in particular between 1 and 4 mm. At least one dimension of the glass sheet is preferably at least 1 m.
• the glass sheet can be clear, or preferably tinted, for example green, gray or blue.
• the composition of the glass comprises dyes, in particular iron oxide, in a total weight content (expressed in the form FeC>) of between 0.05 and 1.5%, in particular between 0.1 and 1.0%.
• the glass sheet is generally flat when the electroconductive patterns are deposited. It is then preferably convex, normally during the heat treatment for firing the electrically conductive patterns.
• the final glazing is therefore preferably curved.
• the face of the glass sheet on which the deposition of the first layer is carried out may first have been coated in part with an enamel coating.
• a black enamel coating may have been deposited by screen printing on the periphery of the glass sheet and part of the electrically conductive patterns (in particular the collecting bands) is then deposited on the enamel coating.
• Such a coating makes it possible to conceal and protect against ultraviolet radiation the seals used for positioning and mounting the glazing in the bodywork opening.
• the enamel coating also helps conceal the collector bands.
• the screen printing step is preferably carried out by positioning a screen printing screen facing the glass sheet and then depositing, in particular using a doctor blade, on the screen printing screen an electrically conductive paste, in particular with the silver.
• the meshes of the screen are sealed in the part corresponding to the areas of the sheet of glass that one does not want to cover, so that the paste cannot pass through the screen only in the areas to be printed, according to a predefined pattern.
• the electrically conductive patterns are preferably formed from a silver paste.
• the electrically conductive silver paste comprises in the wet state at most 88%, in particular at most 85% by weight of silver, for example from 75 to 85%, in particular from 80 to 84% by weight of silver.
• These pastes with a high silver content compared to the pastes usually used, are particularly suitable for lead-free solder alloys.
• These silver pastes require, in order to ensure good weldability and good resistance to the TCT test, to apply greater thicknesses thereof to the weld zones, which becomes possible thanks to the method according to the present invention.
• the thickness in the wet state is typically of the order of 25 ⁇ m for a paste containing 80% by weight of silver, and of the order of 35 to 40. pm for a paste containing 75% by weight of silver.
• the paste further comprises a solvent, an organic medium, intended to facilitate deposition by screen printing, and a glass frit, which, after melting, fixes the silver particles on the glass sheet.
• the screen can be made of any material known for making screen printing screens, for example polyester or polyamide.
• the screen is preferably obtained by coating with a photocrosslinkable emulsion on at least part of the surface of the screen, drying the screen, insulating the screen. in order to crosslink the photocrosslinkable emulsion in predetermined zones, followed by washing and drying of the screen.
• the photocrosslinkable emulsion makes it possible to selectively close the meshes of the screen in the areas subjected to insolation, the washing step serving in particular to eliminate the emulsion in the areas not subjected to insolation, therefore in the parts. where the meshes must remain unblocked and through which the printing paste must pass during screen printing and coat the glass sheet to form the electrically conductive patterns.
• the exposure step is the step during which the photoreticle emulsion, generally under the effect of ultraviolet radiation.
• This step is typically carried out by placing a slide against the screen comprising a transparent support, typically made of polyester, coated with patterns of an ink opaque to ultraviolet radiation, corresponding to the electrically conductive patterns to be printed on the glazing, then by irradiating said slide at means of ultraviolet radiation.
• the emulsion is therefore not crosslinked and closes the mesh of the sieve only in the parts of the screen located under the parts of the slide not covered with ink. In the other parts, the emulsion is not crosslinked and is removed during the washing step, leaving the meshes open, so that the paste can pass through them during screen printing.
• the patterns appearing on the slide are thus found identically on the glazing.
• the screen printing screen has an identical mesh size at all points.
• the thickness of the first layer is then identical at all points of the glazing.
• 90 wires per cm can be chosen for the screen for wire diameters of 40 to 48 ⁇ m.
• the wet thickness of the first layer is preferably between 25 and 30 ⁇ m, giving after baking thicknesses of the order of 8 mpi for silver pastes containing 80% by weight of silver.
• the screen printing screen comprises a central part and at least one side part, the size of the mesh in the central part being larger than the size of the mesh in the at least one side part.
• the number of threads per cm in the central part is greater than the number of threads per cm in the at least one side part, and the diameter of the threads in the central part is less than the diameter of the threads in the at least one part. lateral.
• This type of screen makes it possible in particular to deposit a greater thickness of electrically conductive paste at the level of the lateral parts, which correspond to the positioning of the collecting strips (or bus bars), compared to the printing zones corresponding to the finer wires of the heating network.
• this type of sieve mention may be made of the product Vario® from SEFAR or Variant® from SAATI, which makes it possible, during the same printing, to obtain different thicknesses in different areas of the glazing.
• the screen is rectangular or substantially rectangular, and the central part corresponds to the rectangular part, extending over the entire length of the small sides of the screen, including the perpendicular bisector of the small ones. sides corresponds to the perpendicular bisector of the long sides of the screen, and which occupies 20 to 40% of the screen surface.
• the screen preferably comprises two lateral parts, corresponding to the two rectangular parts arranged symmetrically with respect to the perpendicular bisector of the long sides of the rectangle, on either side of the latter, occupying 20 to 40% of the surface of the rectangle. screen.
• Digital printing is preferably performed using a print head whose movement (in particular position and speed) is computer controlled. Several printing techniques are possible.
• the digital printing technique is, for example, inkjet printing.
• the print head comprises nozzles through which drops of ink are projected locally onto the glass sheet. This technique is sometimes called “drop on demand” (DOD).
• DOD drop on demand
• the digital printing technique can also be transfer printing, in particular by laser transfer.
• a support in particular rotary, coated with ink (here the conductive paste) is placed opposite the glass sheet and the print head locally emits a laser beam focused on a part of the support, causing the creation of a drop of ink which is deposited on the sheet of glass.
• the inkjet printing technique imposes extremely fine particle sizes, compatible with the diameters of the nozzles, as well as very low paste viscosities.
• transfer printing techniques do not impose any constraints in terms of composition or particle size of the conductive pastes.
• the ink preferably comprises a glass frit, a solvent as well as silver particles.
• the thickness of the electrically conductive patterns in the or each zone of excess thickness is preferably at least 8 ⁇ m, in particular between 10 and 20 ⁇ m, or even between 10 and 15 ⁇ m after the baking heat treatment step. Such a thickness makes it possible to meet the requirements of the TCT test.
• the thickness of the patterns in the zones other than the extra thickness zone is preferably at most 8 ⁇ m, in particular between 3 and 7 ⁇ m.
• the glazing may or may not be dried after the application of the paste.
• the glazing then undergoes a heat treatment in order to bake the first and the second layer.
• This heat treatment is typically a treatment for bending and / or toughening the glass.
• the bending can in particular be carried out for example by gravity (the glass deforming under its own weight) or by pressing, at temperatures typically ranging from 550 to 720 ° C.
• the final glazing is in particular a rear window of a motor vehicle, a side glazing of a motor vehicle or even a windshield of a motor vehicle.
• the electrically conductive patterns are in particular antennas, collecting bands, alarm wires and / or heating wires.
• the collector strips are preferably located in the two opposite side parts of the glazing.
• the heating wires are preferably located mainly in the central part of the glazing, and extend parallel to the long edge of the glazing between the two collector strips. This is particularly the case for a rear window.
• the or each zone of excess thickness includes or is a weld zone for connection of an antenna and / or a heating network and / or an alarm.
• the electrically conductive patterns are in particular antennas.
• the electrically conductive patterns can also be heating wires providing local heating in the camera windows, for example for detecting the distance from the front vehicle.
• the electrically conductive patterns are in particular antennas or alarm wires.
• FIG. 1 represents a glazing obtained according to the invention, in the example a rear window of a motor vehicle.
• the glazing 1 comprises a sheet of glass 2 having a central part A and two side parts C.
• these parts A and C have been printed electrically conductive patterns 4, 6, 8, 10, more precisely a network of horizontal heating wires 4 and vertical, connected in the lateral parts C to collecting bands 8, an antenna 6, a welding zone for antenna button 10.
• the collecting bands 8 comprise a welding zone 12 for supplying the network heating.
• the position of the weld zones 12, in the lower part of the collecting strips 8, is shown diagrammatically in the figure by the dotted lines.
• the wires 4, 6, and collecting bands 8 as well as the antenna button 10 have been screen printed with a silver paste (comprising 80% by weight of silver) on the glass sheet 2, to form a first layer, the wet thickness of which at the level of the collecting bands was in the example 25 ⁇ m (giving after baking a 8 ⁇ m thickness).
• a black enamel coating (not shown) was deposited by screen printing on the periphery of the glass sheet 2, in the form of a peripheral strip.
• the electrically conductive patterns 6, 8 and 10 have therefore been deposited on this enamel coating.
• Zone 10A is a zone corresponding to a weld zone for connection of antenna 6.
• Zones 12A are zones located on collector strips 8 and include weld zones for connection of the heating network.
• the electrically conductive patterns therefore have a greater thickness in the areas of extra thickness 10A and 12A than in the other areas, since they consist of the first layer and the second layer superimposed.
• the zones of extra thickness 12A are here wider than the weld zone 12 proper, and therefore “protrude” beyond this zone, in order to avoid undesirable heating in the zones located near the weld zone.
• the areas of extra thickness 12A can correspond exactly to the weld areas 12.
• the glass sheet was then subjected to a thermal bending treatment at a temperature of approximately 620 ° C., step during which the firing of the first and the second layer was also carried out.
• the thickness in the areas of excess thickness 10A and 12A was typically of the order of 10 to 15 ⁇ m. In the other areas the thickness was 8 ⁇ m.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Ceramic Engineering (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Geochemistry & Mineralogy (AREA)
• Organic Chemistry (AREA)
• Materials Engineering (AREA)
• General Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Toxicology (AREA)
• Thermal Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Inorganic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Physics & Mathematics (AREA)
• Surface Treatment Of Glass (AREA)
• Manufacturing Of Printed Wiring (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 2019
  • 2019-11-29 FR FR1913478A patent/FR3103809B1/fr active Active
• 2020
  • 2020-11-27 JP JP2022531345A patent/JP7646658B2/ja active Active
  • 2020-11-27 US US17/773,751 patent/US12495502B2/en active Active
  • 2020-11-27 WO PCT/EP2020/083723 patent/WO2021105422A1/fr not_active Ceased
  • 2020-11-27 EP EP20811413.2A patent/EP4065529A1/de active Pending
  • 2020-11-27 CN CN202080007705.XA patent/CN113226780B/zh active Active

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