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
  • 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
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
• • 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
  • C03C17/3618—Coatings of type glass/inorganic compound/other inorganic layers, at least one layer being metallic
• • 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
  • C03C17/3626—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 one layer at least containing a nitride, oxynitride, boronitride or carbonitride
• • 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
  • C03C17/3639—Multilayers containing at least two functional metal layers
• • 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
  • C03C17/3652—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 coating stack containing at least one sacrificial layer to protect the metal from oxidation
• • 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
  • C03C17/3676—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 as electromagnetic shield
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
  • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
  • G02B1/11—Anti-reflection coatings
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
  • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
  • G02B1/11—Anti-reflection coatings
  • G02B1/113—Anti-reflection coatings using inorganic layer materials only
  • G02B1/115—Multilayers
  • G02B1/116—Multilayers including electrically conducting layers
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/20—Filters
  • G02B5/28—Interference filters
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J11/00—Gas-filled discharge tubes with alternating current induction of the discharge, e.g. alternating current plasma display panels [AC-PDP]; Gas-filled discharge tubes without any main electrode inside the vessel; Gas-filled discharge tubes with at least one main electrode outside the vessel
  • H01J11/20—Constructional details
  • H01J11/34—Vessels, containers or parts thereof, e.g. substrates
  • H01J11/44—Optical arrangements or shielding arrangements, e.g. filters, black matrices, light reflecting means or electromagnetic shielding means
• • 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
  • H05K9/00—Screening of apparatus or components against electric or magnetic fields
  • H05K9/0073—Shielding materials
  • H05K9/0094—Shielding materials being light-transmitting, e.g. transparent, translucent
  • H05K9/0096—Shielding materials being light-transmitting, e.g. transparent, translucent for television displays, e.g. plasma display panel
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/12—All metal or with adjacent metals
  • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
  • Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
  • Y10T428/12542—More than one such component
  • Y10T428/12549—Adjacent to each other
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24942—Structurally defined web or sheet [e.g., overall dimension, etc.] including components having same physical characteristic in differing degree
  • Y10T428/2495—Thickness [relative or absolute]

Definitions

• This invention relates to a plasma display panel (PDP) including a filter at a front portion thereof for blocking/shielding substantial amounts of electromagnetic waves.
• the filter has high visible transmission, and is capable of blocking/shielding electromagnetic waves.
• a PDP includes a plasma display panel on which an image is displayed using a gas discharge phenomenon, and exhibits superior display capabilities, including high display capacity, high brightness, high contrast, clear latent image, a wide viewing angle, etc.
• a direct current (DC) or alternating current (AC) voltage is applied to electrodes, a discharge of gas plasma is created, resulting in the emission of ultraviolet (UV) light.
• PDPs face several challenges associated with driving characteristics, including an increase in electromagnetic wave radiation, near-infrared emission, and phosphor surface reflection, and an obscured color purity due to orange light emitted from helium (He), neon, or xenon (Xe) used as a sealing gas.
• He helium
• Xe xenon
• the transparent conductive film is generally formed of a multi-level thin film structure in which a metal film and a high-refractive- index transparent thin layer are sandwiched. Silver or a silver-based alloy may be used as the metal film.
• convention PDP EMI filters tend to lack durability and/or can stand to be improved upon with respect to visible transmission and/or shielding properties.
• certain PDP EMI filters need to be heat treated (e.g., thermally tempered). Such heat treatment typically requires use of temperature(s) of at least 580 degrees C, more preferably of at least about 600 degrees C and still more preferably of at least 620 degrees C.
• heat treatment and “heat treating” as used herein mean heating the article to a temperature sufficient to achieve thermal tempering and/or heat strengthening of the glass inclusive article. This definition includes, for example, heating a coated article in an oven or furnace at a temperature of least about 580 degrees C, more preferably at least about 600 degrees C, for a sufficient period to allow tempering and/or heat strengthening. In certain instances, the HT may be for at least about 4 or 5 minutes.
• PDP filter which is improved (with respect to conventional PDP EMI filters) with respect to one or more of: (i) improved chemical durability, (ii) improved thermal stability (e.g., upon optional heat treatment such as tempering), (iii) improved visible transmission, and/or (iv) improved EMI shielding properties.
• a plasma display panel includes a filter at a front portion thereof for blocking/shielding substantial amounts of electromagnetic waves.
• the filters has high visible transmission, and is capable of blocking/shielding electromagnetic waves.
• a silver based coating of the EMI filter reduces damage from EMI radiation through highly conductive Ag layers, blocks significant amounts of NIR and IR radiation from outdoor sunlight to reduce PDP panel temperature, and enhances contrast ratio through reduced reflection, while maintaining high visible transmission.
• a plasma display device comprising: a plasma display panel (PDP); an electromagnetic interference (EMI) filter provided at a front portion of the plasma display panel, the EMI filter including an EMI coating supported by a glass substrate, the EMI coating including the following layers moving away from the glass substrate: a first layer comprising silicon nitride; a first high index layer having a refractive index (n) of at least about 2.2; a first layer comprising zinc oxide; a first EMI shielding layer comprising silver contacting the first layer comprising zinc oxide; a first layer comprising an oxide of Ni and/or Cr contacting the first EMI shielding layer comprising silver; a first metal oxide layer; a second layer comprising zinc oxide; a second EMI shielding layer comprising silver contacting the second layer comprising zinc oxide; a second layer comprising an oxide of Ni and/or Cr contacting the second EMI shielding layer comprising silver; a second metal oxide layer; a third layer comprising zinc oxide
• EMI filter for a display device, the EMI filter comprising: an EMI coating supported by a glass substrate, the EMI coating including the following layers moving away from the glass substrate: a first layer comprising zinc oxide; a first EMI shielding layer comprising silver contacting the first layer comprising zinc oxide; a first layer comprising an oxide of Ni and/or Cr contacting the first EMI shielding layer comprising silver; a second layer comprising zinc oxide; a second EMI shielding layer comprising silver contacting the second layer comprising zinc oxide; a second layer comprising an oxide of Ni and/or Cr contacting the second EMI shielding layer comprising silver; a third layer comprising zinc oxide; a third EMI shielding layer comprising silver contacting the third layer comprising zinc oxide; a third layer comprising an oxide of Ni and/or Cr contacting the third EMI shielding layer comprising silver; and an overcoat layer; wherein the third EMI shielding layer comprising silver is thicker than the first and/
• plasma display device comprising: a plasma display panel; an electromagnetic interference (EMI) filter provided at a front portion of the plasma display panel, the EMI filter including an EMI coating supported by a glass substrate, the EMI coating including the following layers moving away from the glass substrate: a first layer comprising silicon nitride; a first layer comprising zinc oxide; a first EMI shielding layer comprising silver contacting the first layer comprising zinc oxide; a first layer comprising an oxide of Ni and/or Cr contacting the first EMI shielding layer comprising silver; a first metal oxide layer; a second layer comprising zinc oxide; a second EMI shielding layer comprising silver contacting the second layer comprising zinc oxide; a second layer comprising an oxide of Ni and/or Cr contacting the second EMI shielding layer comprising silver; a second metal oxide layer; a third layer comprising zinc oxide; a third EMI shielding layer comprising silver contacting the third layer comprising zinc oxide; a third layer comprising an oxide of Ni and/or Cr contacting the third
• the first layer comprising silicon nitride comprises Si x N y layer(s), where x/y is from 0.76 to 1.5 (more preferably from about 0.85 to 1.2).
• Fig. l(a) is a cross sectional view of an EMI filter for a display panel
• PDP panel e.g. PDP panel
• Fig. l(b) is a cross sectional view of a PDP panel including an EMI filter (e.g., the filter of any embodiment herein) according to an example embodiment of this invention.
• an EMI filter e.g., the filter of any embodiment herein
• Fig. 2 is a transmission/reflectance vs. wavelength graph illustrating optical characteristics of the filter of Fig. l(a) according to an example embodiment of this invention.
• FIG. 3 is a cross sectional view of an EMI filter for a display panel (e.g.
• Fig. 4 is a listing of the layers of an EMI filter for a display panel (e.g.
• Fig. 5 is a listing of the layers of an example antireflection (AR) coating which may optionally be used in conjunction with an EMI coating in certain example embodiments of this invention.
• AR antireflection
• Fig. 6 is a cross sectional view of the EMI filter (TCC) (of any embodiment of this invention), front cover glass, and optional AR coating for use at the front of a PDP panel according to an example embodiment of this invention.
• TCC EMI filter
• Fig. 7 is a cross sectional view of the EMI filter (TCC) (of any embodiment of this invention), front cover glass, and a pair of optional AR coatings for use at the front of a PDP panel according to another example embodiment of this invention.
• TCC EMI filter
• Fig. 8 is a cross sectional view of the EMI filter (TCC) (of any embodiment of this invention), front cover glass, and a pair of optional AR coatings for use at the front of a PDP panel according to another example embodiment of this invention.
• TCC EMI filter
• Fig. 9 is a table listing example optical characteristics of filter structures of certain example embodiments of this invention.
• Fig. 10 is a transmission (T)/reflectance (R) vs. wavelength graph illustrating optical characteristics of the filters according to various example embodiments of this invention.
• Fig. 11 is a graph illustrating normalized absorption spectrum of example optional pink dye which may be used in certain example embodiments of this invention.
• Fig. 12 is a table listing example optical characteristics of filter structures of certain example embodiments of this invention which include the use of dye.
• Fig. 13 is a transmission (T)/reflectance (R) vs. wavelength graph illustrating optical characteristics of the filters according to various example embodiments of this invention which include the use of dye.
• Fig. 14 is a cross sectional view of an EMI filter for a display panel
• PDP panel e.g. PDP panel
• Fig. 15 is a cross sectional view of an EMI filter for a display panel
• PDP panel e.g. PDP panel
• Fig. 16 is a cross sectional view of an EMI filter for a display panel
• PDP panel e.g. PDP panel
• Fig. 17 is a cross sectional view of an EMI filter for a display panel
• PDP panel e.g. PDP panel
• Fig. 18 is a cross sectional view of an EMI filter for a display panel
• PDP panel e.g. PDP panel
• Fig. 19 is a cross sectional view of an EMI filter for a display panel
• PDP panel e.g. PDP panel
• a plasma display panel includes a filter at a front portion thereof for blocking/shielding substantial amounts of electromagnetic waves.
• the filter has high visible transmission, and is capable of blocking/shielding substantial portions of electromagnetic waves.
• Certain example embodiments of this invention relate to an Ag-based multiple layered transparent conductive coating (TCC) for display applications (e.g., PDP applications).
• TCC transparent conductive coating
• This EMI filter coating includes three or more Ag based layers sandwiched between metal oxides, nitrides or oxynitrides. It provides the functions of blocking EMI radiation and minimizing/reducing near infrared and infrared transmissions.
• the Ag based transparent conductive coating can be manufactured by magnetron sputtering on glass in certain example embodiments.
• the coating on glass may go through a post heat-treatment in a typical oven or tempering furnace to enhance glass strength and increase coating conductivity and transparency in certain example embodiments (i.e., heat treatment).
• the Ag-based TCC (or EMI filter) coating includes or consists of four layers of ZnOx/Ag/NiCrOx sandwiched between metal oxides and nitrides.
• the metal oxides (e.g., tin oxide, zinc oxide) and nitrides (e.g., silicon nitride) used have refractive indices (n) in visible higher than 1.8, and can be nonconductive such as SiNx or conductive such as ZnAlOx.
• the materials are the same for all three or four stacks, but the thickness of the dielectric and Ag layers are adjusted to meet the sheet resistance and optics targets for each of the layer stacks.
• other layers may differ from stack to stack in order to enhance durability and optical performance.
• the EMI filter may also include a conductive frit frame around the periphery to provide a low conductance contact to the housing of the plasma TV.
• the completed filter may also include AR coating film laminated to the front surface to reduce display reflectance and a laminate with a purple and/or pink dye attached to the back of the coated glass to improve color performance of the plasma TV.
• Figure 1 (a) is a cross sectional view of an EMI filter for use in a PDP panel (or other type of display panel) according to an example embodiment of this invention.
• Fig. l(b) is a cross sectional view illustrating the filter of Fig. l(a) on a PDP panel.
• the filter of Fig. l(a) is provided on the interior side (side facing away from the sun) of a front cover glass substrate at the front of the PDP.
• the EMI filters according to example embodiments of this invention may or may not be used in conjunctions with antireflection (AR) coatings.
• An AR coating may be provided on the cover glass, on the opposite or the same side as the EMI filter coating.
• the PDP panel 40 shown in Fig. 1 (b) may be any suitable type of PDP panel.
• Example PDP panels are described in US 2006/0083938 (e.g., see Fig. 6), the entirety of which is incorporated herein by reference.
• the Fig. l(a) filter structure may be used in place of 100 or 100' in the PDP device of Fig. 6 of US 2006/0083938, as an example application of this invention.
• cover glass substrate 1 e.g., clear, green, bronze, or blue-green glass substrate from about 1.0 to 10.0 mm thick, more preferably from about 1.0 mm to 3.5 mm thick
• EMI filter coating (or layer system) 30 provided on the substrate 1 either directly or indirectly.
• the coating (or layer system) 30 includes: dielectric silicon nitride base layer 3 which may be Si 3 N 4 , of the Si-rich type for haze reduction, or of any other suitable stoichiometry in different embodiments of this invention, high index titanium oxide inclusive layer 4, first lower contact layer 7 (which contacts conductive EMI shielding layer 9), first conductive and preferably metallic EMI shielding layer 9, first upper contact layer 11 (which contacts layer 9), dielectric or conductive metal oxide layer 13 (which may be deposited in one or multiple steps in different embodiments of this invention), second lower contact layer 17 (which contacts EMI shielding layer 19), second conductive and preferably metallic EMI shielding layer 19, second upper contact layer 21 (which contacts layer 19), dielectric or conductive metal oxide layer 23, dielectric silicon nitride based layer(s) 25, 26 which may be Si 3 N 4 , of the Si-rich type for haze reduction, or of any other suitable stoichiometry in different embodiments of this invention, second high index titanium oxide inclusive layer 24, third lower contact
• the "contact" layers 7, 11, 17, 21, 27, 31, 37 and 41 each contact at least one EMI shielding/reflecting layer (e.g., layer based on Ag) (9, 19, 29, 39).
• the aforesaid layers 3-45 make up the EMI shielding coating 30 which is provided on substrate 1 for blocking substantial amounts of EMI from being emitted from the PDP device.
• Example sheet resistances are 0.8, 1.2 and 1.6 ohm/sq. for the coatings 30 in different example embodiments, hi certain example embodiments, the coating 30 may have a sheet resistance of from about 0.5 to 1.8 ohms/sq. [0037]
• tin oxide based layer 13 would be replaced with a first tin oxide based layer 13 ' , a silicon nitride layer 13" and a second tin oxide based layer 13'".
• tin oxide based layer 33 would be replaced with a first tin oxide based layer 33', a silicon nitride layer 33" and a second tin oxide based layer 33'".
• This alternative layer stack is particularly advantageous with respect to heat treated and heat treatable filters that may be used when, for example, bus bar/black frit is applied on top of the coating 30.
• the use of the NiCrOx material for layers 11, 21, 31 and 41 is advantageous in that it is more durable and provides for better thermal stability compared to other possible materials such as zinc oxide or zinc aluminum oxide.
• Dielectric layers 3, 25, 26 and 45 preferably have a refractive index (n) of from about 1.9 to 2.1, more preferably from about 1.97 to 2.08, and may be of or include silicon nitride in certain embodiments of this invention.
• Silicon nitride layers 3, 3a, 25, 26 and 45 may, among other things, improve heat-treatability of the coated articles, e.g., such as thermal tempering or the like.
• the silicon nitride of one, two or all of these layers may be of the stoichiometric type (Si 3 N 4 ) type, or alternatively of the Si-rich type in different embodiments of this invention.
• Si-rich silicon nitride 3, 3a, 26 combined with zinc oxide inclusive layer 7 (and/or 27) under a silver based EMI shielding layer 9 (and/or 29) may permit the silver to be deposited (e.g., via sputtering or the like) in a manner which causes its sheet resistance to be lessened compared to if certain other material(s) were under the silver (and thus, EMI shielding to be improved).
• the presence of free Si in a Si-rich silicon nitride inclusive layer 3 and/or 3 a may allow certain atoms such as sodium (Na) which migrate outwardly from the glass 1 during HT to be more efficiently stopped by the Si-rich silicon nitride inclusive layer before they can reach the silver and damage the same.
• Na sodium
• the Si-rich Si x N y can reduce the amount of damage done to the silver layer(s) during HT in certain example embodiments of this invention thereby allowing sheet resistance (R s ) to decrease in a satisfactory manner and EMI shielding to be improved.
• the Si-rich silicon nitride layer as deposited may be characterized by Si x Ny layer(s), where x/y may be from 0.76 to 1.5, more preferably from 0.8 to 1.4, still more preferably from 0.85 to 1.2.
• the Si-rich Si x N y layer(s) may have an index of refraction "n" of at least 2.05, more preferably of at least 2.07, and sometimes at least 2.10 (e.g., 632 nm) (note: stoichiometric Si 3 N 4 which may also be used has an index "n" of 2.02-2.04).
• stoichiometric Si 3 N 4 which may also be used has an index "n" of 2.02-2.04.
• improved thermal stability is especially realizable when the Si-rich Si x N y layer(s) as deposited has an index of refraction "n" of at least 2.10, more preferably of at least 2.2, and most preferably from 2.2 to 2.4.
• the Si-rich Si x N y layer in certain example embodiments may have an extinction coefficient "k" of at least 0.001, more preferably of at least 0.003 (note: stoichiometric Si 3 N 4 has an extinction coefficient "k” of effectively 0).
• "k" for the Si-rich Si x N y layer is from 0.001 to 0.05 as deposited (550 nm). It is noted that n and k tend to drop due to heat treatment. Any and/or all of the silicon nitride layers (3, 25, 26, 45) discussed herein may be doped with other materials such as stainless steel or aluminum in certain example embodiments of this invention.
• any and/or all silicon nitride layers discussed herein may optionally include from about 0- 15% aluminum, more preferably from about 1 to 10% aluminum, most preferably from 1-4% aluminum, in certain example embodiments of this invention.
• the silicon nitride may be deposited by sputtering a target of Si or SiAl in certain embodiments of this invention. These layers are provided in order to improve the reflection of EMI without sacrificing visible transmission.
• High index layers 4 and 24 are preferably of or including an oxide of titanium (e.g., TiO 2 , or other suitable stoichiometry) in certain example embodiments of this invention.
• Layers 4 and 24 preferably have a refractive index (n) of at least about 2.2, more preferably of at least about 2.3, 2.4 or 2.45, in certain example embodiments of this invention.
• These layers 4 and 24 may be conductive or dielectric in different example embodiments of this invention. These layers are provided in order to improve the reflection of EMI without sacrificing visible transmission.
• EMI shielding/reflecting layers 9, 19, 29 and 39 are preferably substantially or entirely metallic and/or conductive, and may comprise or consist essentially of silver (Ag), gold, or any other suitable EMI reflecting material.
• EMI shielding layers 9, 19, 29 and 39 help allow the coating to have good conductivity and block EMI from being emitted from the PDP panel. It is possible for these layers to be slightly oxidized in certain embodiments of this invention.
• the upper contact layers 11, 21, 31 and 41 may be of or include nickel
• NiCrO x nickel chrome oxide
• the use of, for example, NiCrO x in these layers allows durability to be improved.
• the NiCrO x of layers 11 and/or 21 may be fully oxidized in certain embodiments of this invention (i.e., fully stoichiometric), or alternatively may only be partially oxidized. In certain instances, the NiCrO x layers may be at least about 50% oxidized. These layers (e.g., of or including an oxide of Ni and/or Cr) may or may not be oxidation graded in different embodiments of this invention.
• Oxidation grading means that the degree of oxidation in the layer changes throughout the thickness of the layer so that for example a contact layer may be graded so as to be less oxidized at the contact interface with the immediately adjacent IR reflecting layer than at a portion of the contact layer(s) further or more/most distant from the immediately adjacent IR reflecting layer, and these contact layers may or may not be continuous in different embodiments of this invention across the entire IR reflecting layer.
• the use of the NiCrOx material for one, two, three or all of layers 11, 21, 31 and 41 is advantageous in that it is more durable and provides for better thermal stability compared to other possible materials such as zinc oxide or zinc aluminum oxide. This is especially the case with respect to heat treated and heat treatable filters that may be used when, for example, bus bar/black frit is applied on top of the coating 30 in certain applications.
• Metal oxide layers 13, 23, 33 and 43 may be of or include tin oxide in certain example embodiments of this invention. These layers preferably have a refractive index (n) of from about 1.9 to 2.1 in certain example embodiments of this invention, more preferably from about 1.95 to 2.05. These layers may be doped with other material such as zinc in certain instances. However, as with other layers herein, other materials may be used in different instances. These layers are provided in order to improve the reflection of EMI without sacrificing visible transmission.
• Lower contact layers 7, 17, 27 and 37 in certain embodiments of this invention are of or include zinc oxide (e.g., ZnO).
• the zinc oxide of these layers may contain other materials as well such as Al (e.g., to form ZnAlO x ).
• one or more of these zinc oxide layers may be doped with from about 1 to 10% Al, more preferably from about 1 to 5% Al, and most preferably about 2 to 4% Al.
• the use of zinc oxide under the silver 9, 19, 29, 39 allows for an excellent quality of silver to be achieved thereby improving conductivity and improving EMI shielding.
• the Ag-based EMI shielding layers in the coating have different thicknesses. This is by design, and is particularly advantageous.
• the different thicknesses of the silver based layers 9, 19, 29, 39 are optimized to obtain a low visible reflection as seen from outside of the PDP apparatus (i.e., from the glass side of the film, in most embodiments, namely when the coating 30 is on the interior surface of the substrate 1 facing the plasma), and at the same time permitting high visible transmittance.
• Silver layers buried deeper in the stack i.e., further from the plasma
• they can be made thicker to improve EMI shielding without adversely affecting outside reflectance to any significant extent.
• the thickness (physical thickness) of a silver based EMI shielding layer(s) (e.g., 39) further from the plasma of the PDP panel can be significantly thicker than the thickness of a silver based EMI shielding layer(s) (e.g., 9) closer to the plasma of the PDP panel.
• the total silver thickness is unevenly distributed across the coating 30 in order to take advantageous of this effect.
• the total thickness of all silver based layers (9, 19, 29, 39) combined may be from about 25-80 ran in certain example embodiments of this invention, more preferably from about 30-70 nm, whereas the total thickness of the entire coating 30 may be from about 300 to 400 nm, more preferably from about 325 to 380 nm, and most preferably from about 330 to 375 in certain example embodiments of this invention.
• the thickness (physical thickness) of a silver based EMI shielding layer(s) (e.g., 39 or 29) further from the plasma of the PDP panel is at least about 1 nm thicker (more preferably at least about 2 nm thicker, and possibly at least about 3 or 4 nm thicker) than the thickness of a silver based EMI shielding layer(s) (e.g., 9) closer to the plasma of the PDP panel.
• Fig. 2 is a transmission/reflectance vs. wavelength graph illustrating optical characteristics of the filter of Fig. l(a) when designed for a sheet resistance of 0.8 ohms/square, thereby having thick silver layer(s).
• T stands for transmission
• G stands for glass side reflectance
• F film side reflectance.
• film side i.e., the side closest to the plasma
• visible transmission e.g., from 450-650 nm
• the combination of the coating 30 and the substrate 1 have a visible transmission of at least about 50%, more preferably of at least about 55%, 58% or 60% in certain example embodiments of this invention.
• FIG. 3 is a cross sectional view of an EMI filter for a display panel (e.g.
• the Fig. 3 embodiment is the same as the Fig. l(a)-(b) embodiment discussed above, except that certain thicknesses are different because the Fig. 3 filter is designed for a higher sheet resistance (Rs of 1.64 ohms/square).
• example thicknesses and materials for the respective layers on the glass substrate 1 in the Fig. 1-3 embodiments are as follows, from the glass substrate outwardly:
• NiCrO x (layer 41) 0.3-4 0.5-2 1
• Fig. 4 describes an
• the Fig. 4 coating 30 including four layer stacks of ZnOx/Ag/NiCrOx sandwiched between metal oxides and nitrides.
• the Fig. 4 coating has different thicknesses than the coating of Figs. 1-3, and also in Fig. 4 the layers 3, 25, 26, 24, 43 from the Fig. 1-3 embodiments have been removed. This shows that all layers in the Fig. 1 embodiment are not essential, and some may be removed in certain instances.
• 4 coating 30 may have a sheet resistance less than 1.5 ohm/sq and 1.0 ohm/sq measured as coated and after heat-treatment, respectively, in certain example embodiments, and a neutral transmission in visible higher than 55% or 60% in certain example embodiments.
• the sheet resistance can be further reduced through the trade-off of transmission in visible by increased Ag thickness. If a lower transmission is desired, the transmission can be reduced by increased NiCrOx thickness and/or reduced x value.
• Metal oxides and nitrides should have optical index in visible higher than 1.8, and can be nonconductive such as SiNx or conductive such as ZnAlOx in different example embodiments.
• a multiple layer structure can also be used to replace each metal oxide, nitride, or oxynitride, such as replacing TiOx by SiNx/TiOx or SnOx by SnOx/SiNx/ZnOx.
• a broad band visible antireflection (AR) coating 50 such as the one described in Fig. 5 or any other suitable AR coating, can be applied on the opposite surface of the substrate 1 (see Figs. 6-8) and/or laminated atop of the TCC 30 (see Figs. 7-8) to further enhance the optical performance of the Ag based EMI protection coating 30 in certain example embodiments of this invention.
• Examples of using this Ag based TCC coating for display applications are shown in Figs. 6-8.
• the various Fig. 6-8 filter structures may be used in place of 100 or 100' in the PDP device of Fig. 6 of US 2006/0083938, in example applications of this invention. Note that in Figs.
• optional additional substrate(s) 1 ', 1 " may be glass or plastic, and the glue may be any suitable adhesive or the like.
• a TCC coating 30 having 4 layers of Ag (as shown in Figs. 1 (a), 3 and 4) is used as part of cover glass 1 structure for outdoor display applications, and Figs. 6-8 illustrate example designs of this cover glass structure with the optional possibility of using it together with an AR coating 50.
• Optical performance of example is summarized in Fig. 9 when TCC 30 (e.g., see Fig. 4, or Fig. 1) and AR (e.g., see Fig. 5) are coated on opposite surfaces of the substrate 1. Transmission and reflection spectra details are shown in Fig. 10.
• the TCC EMI filter coating 30 provides the following functions/advantages: reduces damage from EMI radiation through highly conductive Ag layers, block significant amounts of NIR and IR radiation from outdoor sunlight to reduce panel temperature, and enhances contrast ratio through reduced reflection.
• Figs. 11-13 another example of this invention is similar to the embodiments of Figs. 1-10, but also includes an extra dye(es) based absorption layer(s) to reduce transmission at about 595nm (as shown in Figure 11) to improve color neutrality for plasma display applications.
• the dye is for absorbing at selected wavelength ranges, but not other ranges.
• the dye may absorb light proximate 595 nm (e.g., see Fig. 11) in order to improve color characteristics of PDP devices.
• the dye inclusive layer (not shown) can be introduced into one or more locations, such as between AR coating 50) and substrate (1), or between TCC 30 and substrate 1, or between TCC 30 and the glue layer, or embedded in the glue layer or substrate(s) 1 (see Figs. 6-8).
• the optical performance of an example of this dye inclusive embodiment for PDP devices is shown in Fig. 12, and transmission and reflection spectra of an example of this embodiment are shown in Fig. 13.
• the TCC coating 30 provides the following functions: block the emitting of EMI radiation from plasma panel by highly conductive Ag layers, block NIR and IR radiation from sunlight to reduce panel temperature for outdoor usage, enhance contrast ratio through reduced reflection, and block the emitting of NIR (850-950nm) radiation from plasma panel to avoid the interference to nearby electronics.
• Figs. 14-19 are cross sectional views of EMI filters for display panels
• EMI filter coatings of these embodiments may be heat treated in a typical or conventional tempering furnace, so that the glass substrate 1 is tempered when the coated article is heat treated. Suitable black and/or silver frits can be applied to and fired onto the coated surface with good adhesion and no significant damage to the coated surface.
• Figs. 14-19 are heat treatable (HT) versions and the coatings of these embodiments can survive heat treatment at temperature of from about 500-750 degrees C (more preferably from about 520-650 degrees C) while still maintaining an acceptable haze value following HT; and the coatings of these embodiments can have a sheet resistance (Rs) of no more than about 1.3 or 1.2 ohms/square (more preferably no more than about 1.0 or 0.90 ohms/square), and a visible transmission of at least about 60% (more preferably at least about 62 or 63%), following HT.
• the coated articles of these embodiments have a haze value of no more than about 3 (more preferably no more than about 2.0 or 1.0) following HT.
• silicon nitride based layer(s) 3 and/or 3a may be Si-rich as discussed above in certain example embodiments, and NiCr oxided based layer(s) 31 and/or 41 is/are only partially oxided in certain example embodiments.
• the use of such Si-rich silicon nitride and only partially oxiding at least one of the NiCrOx based layers results in a coated article that is better able to withstand HT while maintaining suitable visible transmission and haze values following HT.
• NiCrOx based layer 41 is less oxided than are one, two or all three of NiCrOx based layers 11, 21 and/or 31.
• NiCrOx based layer(s) 31 and/or 41 is/are less oxided than are one or both of NiCrOx based layer(s) 11 and/or 21; it has been found that this helps provide for a more heat treatable coating with better thermal stability upon HT.
• metal oxide e.g., tin oxide
• tin oxide tin oxide

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