Patent Description:
Multiple-pane insulating glazing units ("IG units") having both a transparent conductive oxide ("TCO") film and bus bars are known. IG units of this nature are used, for example, in the doors of certain refrigerators. In such IG units, the bus bars are conventionally in contact with the TCO film. In such conventional designs, no overcoat film is provided over the TCO film. These types of arrangements involve the TCO film being exposed, which may be suboptimal for various reasons. For example, without using an overcoat film, it can be difficult to precisely control the stoichiometry of the TCO and achieve exceptional levels of both electrical conductivity and visible transmittance. Moreover, the bus bars in conventional designs are readily visible, and this tends to be objectionable aesthetically.

As set forth in the present disclosure, it would be desirable to provide an IG unit that has both a coating and a bus bar, wherein the bus bar is spaced apart from the coating. It would be particularly desirable to provide such an IG unit where the coating includes a TCO film and an overcoat film. Still further, it would be desirable to provide a bus bar that is connected electrically to the TCO film by virtue of a transparent conductor bridge extending from the bus bar to a top surface of the overcoat film. Additionally or alternatively, it would be desirable to provide an IG unit having a frit, wherein the bus bar is concealed behind the frit.

<CIT> describes a pane having a heatable coating, comprising a substrate and a heatable coating on an exposed surface of the substrate, which heatable coating at least comprises: an electrically conductive layer, which contains a transparent, electrically conductive oxide (TCO) and has a thickness of <NUM> to <NUM>, and above the electrically conductive layer a dielectric barrier layer for regulating oxygen diffusion, which dielectric barrier layer contains a metal, a nitride, or a carbide and has a thickness of <NUM> to <NUM>, the pane having a transmittance in the visible spectral range of at least <NUM>% and the coating having a sheet resistance of <NUM> ohms/square to <NUM> ohms/square.

<CIT> describes a heatable transparency includes a first ply having a No. <NUM> surface and a No. <NUM> surface and a second ply having a No. <NUM> surface and a No. <NUM> surface. The No. <NUM> surface faces the No. <NUM> surface. An electrically conductive coating is formed on at least a portion of the No. <NUM> or No. <NUM> surface, with the conductive coating including three or more metallic silver layers. An antireflective coating is formed on the No. <NUM> surface.

The features of the invention are given in claim <NUM>, to which reference should now be made. Additional, optional features are given in the dependent claims.

The following detailed description is to be read with reference to the drawings, in which like elements in different drawings have like reference numerals.

The invention involves a coated substrate. A wide variety of substrate types are suitable for use in the present invention. In some embodiments, the substrate is a sheet-like substrate having generally opposed first and second major surfaces.

For many applications, the substrate will comprise a transparent (or at least translucent) material, such as glass or clear plastic. For example, the substrate is a glass sheet (e.g., a glass pane) in certain embodiments. A variety of known glass types can be used, such as soda-lime glass. In some cases, it may be desirable to use "white glass," a low iron glass, etc. In certain embodiments, the substrate is part of a refrigerator door (e.g., is part of an IG unit of a refrigerator door).

Substrates of various sizes can be used in the present invention. Commonly, large-area substrates are used. Certain embodiments involve a substrate having a major dimension (e.g., a length or width) of at least about <NUM> meter, preferably at least about <NUM> meter, perhaps more preferably at least about <NUM> meters (e.g., between about <NUM> meters and about <NUM> meters). Substrates having a major dimension of greater than about <NUM> meters, or of less than about <NUM> meters, are also anticipated.

Substrates of various thicknesses can be used in the present invention. In some embodiments, the substrate (which can optionally be a glass sheet) has a thickness of about <NUM>-<NUM>. Certain embodiments involve a substrate with a thickness of between about <NUM> and about <NUM>, and perhaps more preferably between about <NUM> and about <NUM>. In one particular embodiment, a sheet of glass (e.g., soda-lime glass) with a thickness of about <NUM> is used.

Referring to the drawings, and in particular, <FIG> and <FIG>, there is shown a coated pane <NUM> of the present disclosure generally represented by reference numeral <NUM>. In more detail, the pane <NUM> is a heatable pane. The pane <NUM> has opposed surfaces <NUM> and <NUM>, which preferably are opposed major surfaces.

In some embodiments, the invention provides the pane <NUM> in monolithic form. In other embodiments, the pane <NUM> is part of an IG unit. A desired surface <NUM> of the pane <NUM> bears a coating <NUM> comprising both a transparent conductive oxide ("TCO") film <NUM> and an overcoat film <NUM>. The overcoat film <NUM> is located over (optionally directly over) the transparent conductive oxide film <NUM>. The pane <NUM> further comprises a bus bar <NUM> and a transparent conductor bridge <NUM> both located over the desired surface <NUM>. The bus bar <NUM> is spaced apart from the coating <NUM>. The bus bar <NUM> is connected electrically to the transparent conductive oxide film <NUM> by virtue of the transparent conductor bridge <NUM> extending from the bus bar <NUM> to a top surface <NUM> of the overcoat film <NUM>. Various features, configurations, dimensions, and properties of these elements are described below with reference to embodiments where the pane <NUM> is part of an IG unit.

In many embodiments, the pane <NUM> is part of a multiple-pane insulating glazing unit ("IG unit"). The IG unit <NUM> comprises two panes <NUM>, <NUM> and a between-pane space, which is located between the two panes. The two panes comprise a first pane <NUM> and a second pane <NUM>. A spacer <NUM> is commonly provided that is located between (i.e., so as to separate) the two panes. In some cases, the spacer <NUM> comprises a foam or an elastomer. In other cases, the spacer <NUM> comprises a metal. Various conventional spacers can be used. The spacer <NUM> can be secured between the two panes using an adhesive or a seal. In some cases, an end sealant is also provided. Various conventional sealant systems can be used.

The IG unit <NUM> may have more than two panes and more than one between-pane space. For example, the IG unit may be a triple glazing having three panes and two between-pane spaces. Thus, while some of the following discussion refers to two panes and a between-pane space, it is to be appreciated that the IG unit may include additional panes and between-pane spaces.

In certain embodiments, the between-pane space is filled with an insulative gas mix, such as a mix of <NUM>% argon and <NUM>% air. This, however, is not required. For example, the IG unit may alternatively be filled with air or a desired single gas. In other embodiments, the IG unit <NUM> is a vacuum IG unit. In such embodiments, the two panes may be held apart by a plurality of spacers, which may take the form of small pillars or the like. If desired, part of all of the distance between the panes may be filled with an aerogel.

In IG unit embodiments, a desired surface <NUM> of a selected one of the two panes bears a coating <NUM> comprising both a TCO film <NUM> and an overcoat film <NUM>. The overcoat film <NUM> is located over the TCO film <NUM>. In some cases, the overcoat film <NUM> is located directly over (so as to be in contact with) the TCO film <NUM>. In such cases, the overcoat film <NUM> may be a single layer having an inner face contacting the TCO film <NUM> and an exposed outer face. Furthermore, the TCO film <NUM> can optionally be a single layer.

Examples of suitable coatings that can be used as coating <NUM> of the present disclosure are described in <CIT>and <CIT>.

In certain embodiments, the present coating <NUM> includes, in sequence from surface <NUM> outwardly, an optional base film (not shown), the TCO film <NUM>, and the overcoat film <NUM>. The optional base film, TCO film <NUM>, and overcoat film <NUM> can be provided in the form of discrete layers, thicknesses of graded film, or a combination of both including at least one discrete layer and at least one thickness of graded film. While both the TCO film <NUM> and the overcoat film <NUM> are shown as single layers, either or both can alternatively comprise a plurality of layers. Preferably, all the films of the coating <NUM> are oxide, nitride, or oxynitride films. In some cases, all the films of the coating <NUM> are sputtered films.

When provided, the optional base film can comprise, consist essentially of, or consist of silica, alumina, or a mixture of both. In some cases, silicon oxynitride (optionally containing some aluminum) is used. Silicon nitride (optionally containing some aluminum) may also be used. Combinations of these materials can be used as well. Other films known to be useful as sodium ion diffusion barriers can also be used.

In other embodiments, as shown for example in <FIG> and <FIG>, the TCO film <NUM> is directly on (i.e., in contact with) the desired surface <NUM>. In embodiments of this nature, there is of course no base film.

In preferred embodiments, the TCO film <NUM> comprises, consists essentially of, or consists of indium tin oxide. In alternate embodiments, zinc aluminum oxide, SnO: Sb, SnO: F, or another known TCO material is used. Preferably, the TCO is a sputtered film that includes tin (e.g., such as ITO film or a film comprising tin oxide together with antimony, fluorine, or another dopant). In some cases, the TCO film <NUM> includes carbon nanotubes.

Although a TCO film is described herein, skilled artisans will appreciate that a metallic transparent conductor film can alternatively be used. In such instances, the TCO film <NUM> is omitted and replaced with a metal film, such as a silver film. This can optionally be the case for any embodiment of the present disclosure. For each reference to (and each description relating to) TCO film <NUM> in the present detailed description section, as well as for each figure of the present disclosure showing TCO film <NUM>, it is to be understood that alternative embodiments provide a silver or other metal film in place of the TCO film <NUM>. In such alternative embodiments, for example, the bus bar preferably will be connected electrically to the metal film by virtue of the transparent conductor bridge extending from the bus bar to a top surface of the overcoat film. Furthermore, there can optionally be a conventional thin blocker layer (e.g., comprising one or more of titanium, niobium, nickel, and aluminum) deposited in the form of metal or suboxide film directly over the metal film.

In preferred embodiments, the overcoat film <NUM> comprises transparent dielectric film. The overcoat film <NUM> can optionally be formed of oxide film, nitride film, and/or oxynitride film. In some cases, the overcoat film <NUM> comprises, consists essentially of, or consists of a nitride, such as silicon nitride, aluminum nitride, or a mixture of both. In other cases, oxynitride film (e.g., silicon oxynitride, optionally including some aluminum) is used. In preferred embodiments, the overcoat film <NUM> comprises (or consists essentially of) silicon oxynitride, and the TCO film <NUM> comprises (or consists essentially of) indium tin oxide. When provided, the silicon oxynitride can include aluminum.

In preferred embodiments, the TCO film <NUM> has a thickness in a range of from about <NUM>Å to about <NUM>,<NUM>Å. In some cases, the TCO film <NUM> has a thickness of greater than <NUM>Å but less than <NUM>,<NUM>Å. For example, the TCO film <NUM> can optionally have a thickness of greater than <NUM>Å but less than <NUM>Å (e.g., less than <NUM>Å, less than <NUM>Å, less than <NUM>Å, less than <NUM>Å, less than <NUM>Å, or even less than <NUM>Å). In combination with the TCO film <NUM> having a thickness within any range noted in this paragraph, the TCO film <NUM> can optionally comprise, consist essentially of, or consist of ITO. This can optionally be the case for any embodiment of the present disclosure.

In certain embodiments (e.g., where the overcoat film <NUM> comprises transparent dielectric film), the overcoat film <NUM> has a thickness in a range of from about <NUM>Å to about <NUM>Å. In some cases, the thickness of the overcoat film <NUM> is greater than <NUM>Å but less than <NUM>Å, such as less than <NUM>Å, less than <NUM>Å, less than <NUM>Å, or even less than <NUM>Å. In combination with the overcoat film <NUM> having a thickness with any range noted in this paragraph, the overcoat film <NUM> can optionally comprise, consist essentially of, or consist of oxide, nitride, and/or oxynitride film. This can optionally be the case for any embodiment of the present disclosure, such as those described in the immediately preceding paragraph.

In one non-limiting example, the TCO film <NUM> has a thickness of about <NUM>,<NUM>Å while the overcoat film <NUM> has a thickness of about <NUM>Å. In another non-limiting example, the TCO film <NUM> has a thickness of about <NUM>Å while the overcoat film <NUM> has a thickness of about <NUM>Å. In either of these examples, the TCO film can optionally be ITO while the overcoat film is SiON.

In some embodiments, the selected pane <NUM> is heated prior to film deposition, during deposition, or both. Additionally or alternatively, the coated pane <NUM> can be heat treated after being coated. If desired, post-deposition heat treatment can be performed in air due to the presence of the overcoat film <NUM>. When the coated pane <NUM> is heat treated, defects in the film can be healed and improvement of crystalline structure can occur in the TCO film <NUM> without an uncontrollable change in the chemistry of the TCO. The preferred overcoat film <NUM> can prevent oxygen from reaching the TCO film <NUM> and causing an uncontrollable change in its chemistry during heat treatment.

In certain embodiments, the selected pane <NUM> is a glass pane, such that the coating <NUM> is provided on the glass pane. In some cases, this coated glass pane is heat treated through a process selected such that the coated glass can be cut readily by conventional glass cutting techniques even after the heat treatment. This, for example, can involve using lower temperature for conversion so as to maintain the stress in the glass such that it remains cut-able even after the heat treatment. A variety of known heat-treatment techniques can be used.

Preferably, the TCO film <NUM> has a sheet resistance of between <NUM> ohms/square and <NUM>,<NUM> ohms/square. If the TCO film <NUM> is heat treated, its sheet resistance will depend on how long the TCO film <NUM> is heated and the temperature profile used. In some embodiments, the sheet resistance of the TCO film <NUM> is less than <NUM> ohms/square or less than <NUM> ohms/square (e.g., less than <NUM> ohms/square, less than <NUM> ohms/square, or even less than <NUM> ohms/square). The sheet resistance of the TCO film <NUM> can be measured in standard fashion using a non-contact sheet resistance meter. Other methods known in the art as being useful for determining sheet resistance can also be used. The TCO film <NUM> preferably has a sheet resistance within the broad range given in the first sentence of this paragraph together with having a thickness within any one of the ranges noted above. In some cases, the sheet resistance can also be within any one or more of the ranges noted in the third sentence of this paragraph.

Preferably, the coating <NUM> is formed of materials and made by a process that allow the coated pane <NUM> to have a haze level of less than <NUM> or less than <NUM> (e.g., less than <NUM>, less than <NUM>, or even less than <NUM>), a roughness Ra of less than about <NUM>, less than about <NUM>, or less than about <NUM> (e.g., less than about <NUM>), and a monolithic visible transmission of greater than <NUM>% (perhaps greater than <NUM>%). This can optionally be the case for any embodiment described herein.

Haze can be measured in well-known fashion, e.g., using a BYK Haze-Gard plus instrument. Reference is made to ASTM D <NUM>-<NUM>: Standard Test method for Haze and Luminous Transmittance of Transparent Plastics.

The multiple-pane insulating glazing unit <NUM> further comprises a bus bar <NUM> and a transparent conductor bridge <NUM> each located over the desired surface <NUM>. As shown in <FIG> and <FIG>, the bus bar <NUM> is spaced apart from the coating <NUM>. The bus bar <NUM> is connected electrically to the TCO film <NUM> by virtue of the transparent conductor bridge <NUM> extending from the bus bar <NUM> to a top surface <NUM> of the overcoat film <NUM>. This arrangement allows electrical contact to be made through the overcoat film <NUM>, thereby enabling use of a TCO coating <NUM> having a better combination of electrical resistivity and visible transmission (as compared with a conventional arrangement where a bus bar is provided directly over a TCO film). In some cases, the thickness of the TCO film <NUM> is in a range of from <NUM>Å to <NUM>,<NUM>Å, the thickness of the overcoat film <NUM> is in a range of from <NUM>Å to <NUM>Å, the sheet resistance of the TCO film is between <NUM> and <NUM>,<NUM> ohms/square (and in some cases, less than <NUM> ohms/square, or even less than <NUM> ohms/square), and the monolithic visible transmission of the coated pane <NUM> is greater than <NUM>% (or even greater than <NUM>%).

A wire or other conventional electrical lead can be attached (e.g., by soldering) to the bus bar <NUM>. The wire or other electrical lead is configured to deliver electric current to the bus bar <NUM>. Thus, when electric current is delivered to the bus bar <NUM>, such current then flows from the bus bar, through the transparent conductor bridge <NUM>, and to the TCO film <NUM>. More will be said of this later.

In certain embodiments, the transparent conductor bridge <NUM> comprises a transparent conductive oxide. For example, the transparent conductor bridge <NUM> can optionally comprise tin oxide. Indium tin oxide may be used. SnO: F or SnO: Sb may also be used. However, skilled artisans will appreciate that any TCO can be used for the transparent conductor bridge <NUM>, including any of the transparent conductive oxides discussed above for the TCO film <NUM>.

In preferred embodiments, the transparent conductor bridge <NUM> has a printed bridge structure overlying both the bus bar <NUM> and the coating <NUM>. As shown in <FIG>, <FIG>, and <FIG>, the transparent conductor bridge <NUM> may have a step-like configuration (e.g., optionally having two steps). In some cases, the transparent conductor bridge <NUM> is a printed bridge comprising a printed transparent conductive material. As non-limiting examples, the printed bridge structure can comprise an inkjet-printed or a screen-printed bridge structure. In cases where the transparent conductor bridge <NUM> is inkjet printed, any suitable inkjet printer (e.g., the TECGlass Vitro Jet) can be used. In some cases, the same printer is used to apply (e.g., to inkjet print) the transparent conductor bridge <NUM> and a frit <NUM>, which is described below.

In preferred embodiments, the transparent conductor bridge <NUM> has a thickness that is greater than the thickness of the TCO film <NUM>. This can optionally be the case for any embodiment of the present disclosure. In some cases, the thickness of the transparent conductor bridge <NUM> is in a range of from <NUM>-<NUM> microns (e.g., from <NUM>-<NUM> microns, such as from <NUM>-<NUM> microns, or from <NUM>-<NUM> microns, or even from <NUM>-<NUM> microns). These thickness ranges for the transparent conductor bridge <NUM> can optionally be provided in any embodiment of the present disclosure.

Preferably, an outer region <NUM> of the transparent conductor bridge <NUM> is in contact with the bus bar <NUM>, while an inner region <NUM> of the transparent conductor bridge <NUM> is in contact with the top surface <NUM> of the overcoat film <NUM>. In preferred embodiments, the overcoat film <NUM> is a transparent dielectric film, such that the transparent conductor bridge <NUM> is in contact with underlying transparent dielectric film. As noted above, the overcoat film <NUM> may be an oxide, nitride, or oxynitride film, such that the transparent conductor bridge <NUM> is in contact with underlying oxide, nitride, or oxynitride film.

In some embodiments, the inner region <NUM> of the transparent conductor bridge <NUM> is positioned within a vision area <NUM> of the multiple-pane insulating glazing unit <NUM>. As used herein, the term "vision area" of the IG unit <NUM> refers to the area of the IG unit <NUM> through which a person can see. In <FIG>, for example, the vision area <NUM> of the IG unit <NUM> is shown.

Preferably, the IG unit <NUM> further comprises a frit <NUM>. In such cases, the frit <NUM> is located over the desired surface <NUM> of the pane <NUM> and extends around a perimeter thereof. In embodiments of this nature, the bus bar <NUM> can advantageously be located over the frit <NUM>. As shown in <FIG> and <FIG>, the bus bar <NUM> can optionally be located directly over (i.e., so as to contact) the frit <NUM>.

Typically, the frit <NUM> extends entirely around the perimeter of surface <NUM>. However, it may alternatively be provided only on opposite sides of surface <NUM>, e.g., one section of frit may be located beneath bus bar <NUM> while another section of frit is located beneath bus bar <NUM>.

When provided, the frit <NUM> has two opposed lateral sides <NUM>, <NUM>. In preferred embodiments, the bus bar <NUM> is sized and positioned relative to the frit <NUM> such that no portion of the bus bar <NUM> extends laterally beyond either of the two lateral sides <NUM>, <NUM> of the frit <NUM>. In embodiments of this nature, the bus bar <NUM> has a lateral width that is either the same as, or less than, a lateral width of the frit <NUM>. Such arrangements allow the bus bar <NUM> to be hidden from view behind the frit <NUM>. This may be desirable for various reasons, including certain aesthetic reasons.

Preferably, the frit <NUM> surrounds the vision area <NUM> of the multiple-pane insulating glazing unit <NUM>. In some embodiments, the frit <NUM> delineates the vision area <NUM>, e.g., such that the vision area <NUM> is the area inward from an interior edge <NUM> of the frit <NUM>. However, this need not be the case in all embodiments. For example, the IG unit <NUM> can optionally be mounted in a frame, and sometimes when that is the case the frame delineates the vision area <NUM> (e.g., such that the vision area is the area inward from an interior edge of the frame).

In certain embodiments, the transparent conductor bridge <NUM> includes a first region <NUM>, a second region <NUM>, and a third region <NUM>. Reference is made to <FIG> and <FIG>. In such embodiments, the first region <NUM> is in contact with the bus bar <NUM>, the second region <NUM> preferably is in contact with the frit <NUM>, and the third region <NUM> is in contact with the top surface <NUM> of the overcoat film <NUM>. As shown in <FIG> and <FIG>, the first region <NUM> is part of the outer region <NUM> of the transparent conductor bridge <NUM>, and the third region <NUM> is part of the inner region <NUM> of the transparent conductor bridge <NUM>.

The selected pane <NUM> has an edge <NUM> at a perimeter of the desired surface <NUM>. In <FIG> and <FIG>, the first region <NUM> of the transparent conductor bridge <NUM> is closer to the adjacent edge <NUM> of the selected pane <NUM> than are the second <NUM> and third <NUM> regions of the transparent conductor bridge <NUM>. In addition, the second region <NUM> of the transparent conductor bridge <NUM> is closer to the adjacent edge <NUM> of the selected pane <NUM> than is the third region <NUM> of the transparent conductor bridge <NUM>.

In preferred embodiments, the bus bar <NUM> is positioned outside the vision area <NUM>. Advantageously, such positioning conceals the bus bar <NUM> from view (e.g., when observing pane <NUM> from the glass side as shown in <FIG> and <FIG>). In some cases, part of the transparent conductor bridge <NUM> (including, e.g., the first region <NUM>) is positioned outside the vision area <NUM>. In addition, the third region <NUM> of the transparent conductor bridge <NUM> can optionally be positioned within the vision area <NUM>.

The coating <NUM> may include extremely small defects (e.g., pin holes), as may result from conventional deposition or heat treatment processes. As such, simply heat treating a coated substrate of the nature shown in <FIG> may provide sufficient electrical (ohmic) contact between the TCO film <NUM> and the transparent conductor bridge <NUM>.

In other embodiments, perforations <NUM> are present in the overcoat film <NUM> at locations where the transparent conductor bridge <NUM> contacts the overcoat film <NUM>. Although perforations <NUM> are not required, it may be desirable to form such perforations <NUM> so as to provide improved electrical contact between the bus bar <NUM> and the TCO film <NUM>. As shown in the non-limiting embodiment of <FIG>, the perforations <NUM> allow certain portions of the TCO film <NUM> to be in contact with the transparent conductor bridge <NUM>. The perforations <NUM> may extend through the overcoat film <NUM>, through the TCO film <NUM>, and to the selected pane <NUM>. In other cases, the perforations may not extend all the way to the pane. For example, they may just extend to the TCO film.

In some cases, the perforations <NUM> are laser perforations. In other cases, the perforations <NUM> are mechanically-abraded or chemically-etched areas of the overcoat film <NUM>. Skilled artisans will appreciate that other types of perforations can be used.

When provided, any number and size of perforations <NUM> can be present in the overcoat film <NUM>. In some cases, the perforations <NUM> account for from about <NUM> ppm up to about <NUM>% of the contact area between the transparent conductor bridge <NUM> and the coating <NUM>.

As shown in <FIG> and <FIG>, the coating <NUM> preferably is omitted or removed (e.g., edge-deleted or laser isolated) in certain locations so as to prevent electric current from reaching the edge of the IG unit <NUM>. In some cases, localized coating removal is accomplished by grinding, carving, cutting, or laser ablation. Alternatively, the coating <NUM> may initially be formed only on a central region of the surface <NUM> (e.g., by masking the edge region during deposition). In the embodiment of <FIG>, a peripheral region of coating <NUM> has been removed or omitted. In the embodiment of <FIG>, once a portion of the coating <NUM> has been removed, the coating <NUM> has both a main region <NUM> and a peripheral region <NUM> with a gap therebetween. In such cases, the main region <NUM> of the coating <NUM> is located inwardly of the gap, whereas the peripheral region <NUM> of the coating <NUM> is located outwardly of the gap. Thus, in <FIG>, the gap between peripheral region <NUM> and main region <NUM> prevents electric current from reaching the peripheral region <NUM>.

In cases where a peripheral region of the coating <NUM> is removed or omitted, the frit <NUM> preferably is deposited over such region. In the embodiment of <FIG>, the peripheral region (or "edge region") of surface <NUM> is devoid of coating <NUM>, and the frit <NUM> is provided on surface <NUM> here. Preferably, an inner portion of the frit <NUM> overlaps coating <NUM>. It can optionally be the case that only an inner portion of the frit <NUM> overlaps coating <NUM>. For example, in the non-limiting example shown in <FIG>, an outer portion of the frit <NUM> is provided on (e.g., so as to contact) the peripheral region of surface <NUM> while an inner portion of the frit <NUM> is provided on (e.g., so as to contact) the coating <NUM>.

In the embodiment of <FIG>, some of the frit <NUM> fills the gap between the main region <NUM> and the peripheral region <NUM> of the coating <NUM>. Because the frit <NUM> is electrically insulating, the main region <NUM> of the coating <NUM> is configured to receive electric current, whereas the peripheral region <NUM> of the coating <NUM> is not (i.e., it is electrically isolated). In this type of arrangement, both inner and outer portions of the frit <NUM> overlap the coating <NUM>.

In preferred embodiments, the IG unit <NUM> includes a second bus bar <NUM>. Similar to bus bar <NUM>, the second bus bar <NUM> is spaced apart from the coating <NUM> and located over the desired surface of the selected pane <NUM>. As shown in the non-limiting embodiment of <FIG>, bus bar <NUM> can be located near a top of the selected pane <NUM>, whereas second bus bar <NUM> can be located near a bottom of the selected pane <NUM>. Alternatively, bus bar <NUM> can be located near a first side of the selected pane <NUM>, whereas second bus bar <NUM> can be located near an opposite side of the selected pane <NUM>.

By providing an IG unit <NUM> with both bus bar <NUM> and second bus bar <NUM>, electric current can be delivered to bus bar <NUM> and subsequently delivered from second bus bar <NUM>. The present disclosure is discussed mainly with reference to bus bar <NUM>. However, skilled artisans will appreciate that the second bus bar <NUM> can generally have the same properties, features, and configuration as bus bar <NUM>, except that it is located opposite bus bar <NUM>. In some cases, there is a separate transparent conductor bridge <NUM> for each bus bar <NUM>, <NUM>. In other cases, a single transparent conductor bridge <NUM> extends around an entirety of the selected pane <NUM> such that the same transparent conductor bridge <NUM> extends over (e.g., and contacts) both bus bars <NUM>, <NUM>.

In one group of embodiments, the TCO film <NUM> is an indium tin oxide film. In these embodiments, the overcoat film <NUM> is located over (optionally directly over) the indium tin oxide film. In addition, the bus bar <NUM> is connected electrically to the indium tin oxide film by virtue of the transparent conductor bridge <NUM> extending from the bus bar <NUM> to the top surface <NUM> of the overcoat film <NUM>. In the present group of embodiments, the bus bar <NUM> is located over (optionally directly over) a frit <NUM>, which can be of the nature described above. As such, the frit <NUM> is located over (optionally directly over) surface <NUM> and extends around a perimeter of the surface <NUM>.

Thus, in the present group of embodiments, the TCO film comprises ITO and frit <NUM> is provided. Otherwise, all the foregoing discussions apply to the present embodiment group. For example, the IG unit <NUM> includes second bus bar <NUM>. In addition, both bus bar <NUM> and second bus bar <NUM> are spaced apart from the coating <NUM> and located over the desired surface <NUM> of the selected pane <NUM>.

As can be appreciated by referring to <FIG>, in some embodiments, the multiple-pane insulating glazing unit <NUM> is part of (e.g., is mounted so as to be a component of) a refrigerator door <NUM>. The refrigerator door <NUM> has a closed configuration <NUM> and an open configuration. The IG unit <NUM> has both an interior face and an exterior face <NUM>. In the present embodiments, the interior and exterior <NUM> faces are opposed, such that when the refrigerator door <NUM> is in the closed configuration <NUM>, the interior face of the IG unit <NUM> is exposed to a refrigerated interior environment of a refrigerator <NUM> while the exterior face <NUM> is exposed to an ambient environment. In some embodiments of this nature, the selected pane <NUM> defines the exterior face <NUM> and thus is exposed to the ambient environment. For example, the desired surface of the selected pane can optionally be a #<NUM> surface of the IG unit/refrigerator door and thus exposed to the noted between-pane space. As used herein, the term "refrigerator" refers to any structure (e.g., an appliance, a room, and/or a compartment) having a refrigerated interior environment. This definition includes both refrigerators and freezers.

In the present embodiments, the "first" (or #<NUM>) surface of the IG unit <NUM> is exposed to an ambient environment. The external surface of the outboard pane is the so-called first surface. Moving from the #<NUM> surface inwardly toward the refrigerated interior environment, the next surface is the "second" (or "#<NUM>") surface. Thus, the internal surface of the outboard pane is the so-called second surface. Moving further inwardly toward the refrigerated interior environment, the next surface is the "third" (or "#<NUM>") surface, followed by the "fourth" (or "#<NUM>) surface. This convention is carried forward for IG units having more than four major pane surfaces.

In any embodiment of the present disclosure, the desired surface <NUM> of the selected pane <NUM> can optionally be a #<NUM> surface of the IG unit <NUM> and thus exposed to a between-pane space of the IG unit <NUM>. In some embodiments, the IG unit <NUM> includes more than one coating. In such cases, coatings can be provided, for example, on both the #<NUM> surface and either the #<NUM> surface or the #<NUM> surface. If desired, a coating can also be provided on the #<NUM> surface. For example, a conventional hydrophilic coating may be used.

The IG unit <NUM> can optionally be provided in the form of a triple glazing. In such embodiments, the IG unit <NUM> further comprises a third pane and a second between-pane space. As non-limiting examples of such embodiments, the coating <NUM> can be provided on the #<NUM> surface, or on the #<NUM> surface, or on the #<NUM> surface.

Finally, certain embodiments provide a refrigerator <NUM> having a refrigerator door <NUM> of the type described above. In these embodiments, the multiple-pane insulating glazing unit <NUM> of the door <NUM> comprises two panes and a between-pane space. The between-pane space is located between the two panes. A desired surface <NUM> of a selected one of the two panes bears a coating <NUM> comprising both a transparent conductive oxide film <NUM> and an overcoat film <NUM>. The overcoat film <NUM> is located over the transparent conductive oxide film <NUM>. The coating <NUM> used in the present refrigerator <NUM> embodiments can be of the nature described above for any embodiment of the present disclosure. In addition, the IG unit used in the present refrigerator <NUM> embodiments can be of the nature described above for any embodiment of the present disclosure involving an IG unit <NUM>.

Preferably, the desired surface <NUM> of the selected pane <NUM> faces toward the refrigerated interior environment of the refrigerator <NUM>. In some cases, the desired surface <NUM> of the selected pane <NUM> is exposed to the refrigerated interior environment of the refrigerator <NUM>. In other cases, the desired surface <NUM> of the selected pane <NUM> faces toward, but is not exposed to, the refrigerated interior environment of the refrigerator <NUM>. For example, the desired surface <NUM> of the selected pane <NUM> may be a #<NUM> surface of the IG unit <NUM>, such that the selected pane <NUM> defines the exterior face <NUM> of the IG unit <NUM> and is therefore exposed to the ambient environment. This, however, is not the case in all the present embodiments. For example, the desired surface <NUM> of the selected pane <NUM> can alternatively be a #<NUM> surface or a #<NUM> surface.

Preferably, the IG unit <NUM> of the refrigerator door <NUM> comprises a frit <NUM>, a bus bar <NUM>, and a transparent conductor bridge <NUM> each located over the desired surface <NUM>. When provided, the frit <NUM> preferably extends around (optionally entirely around) a perimeter of the desired surface <NUM>. The bus bar <NUM> is located over the frit <NUM> and is spaced apart from the coating <NUM>. The bus bar <NUM> is connected electrically to the transparent conductive oxide film <NUM> by virtue of the transparent conductor bridge <NUM> extending from the bus bar <NUM> to the top surface <NUM> of the overcoat film <NUM>.

In embodiments of this nature, the outer region <NUM> of the transparent conductor bridge <NUM> preferably is in contact with the bus bar <NUM>, and an inner region <NUM> of the transparent conductor bridge <NUM> preferably is in contact with the top surface <NUM> of the overcoat film <NUM>. In some cases, the inner region <NUM> of the transparent conductor bridge <NUM> is positioned within the vision area <NUM> of the IG unit <NUM>/refrigerator door <NUM>, while the bus bar <NUM> is positioned outside the vision area <NUM>. Furthermore, the transparent conductor bridge <NUM> preferably has first <NUM>, second <NUM>, and third <NUM> regions of the nature described above.

<FIG> are example embodiments of IG units <NUM> of the present disclosure, showing a spacer <NUM> provided in various configurations. In some cases, the spacer <NUM> is located nearer to the edge <NUM> of the selected pane <NUM> than are the transparent conductor bridge <NUM> and the bus bar <NUM>. Reference is made to <FIG> and <FIG>. In other cases, the bus bar <NUM> and the transparent conductor bridge <NUM> are located nearer to the edge <NUM> of the selected pane <NUM> than is the spacer <NUM>. Reference is made to <FIG>.

In more detail, <FIG> shows an arrangement where the spacer <NUM> extends between the frit <NUM> and the second pane <NUM>. In such cases, the bus bar <NUM> and the transparent conductor bridge <NUM> are spaced laterally inwardly from the spacer <NUM> relative to the adjacent edge <NUM> of the selected pane <NUM>. Thus, the spacer <NUM> can optionally be directly on (so as to contact) the frit <NUM>. In other embodiments, as shown in <FIG>, the spacer <NUM> extends between the top surface <NUM> of the overcoat film <NUM> and the second pane <NUM>. In still other embodiments, the frit <NUM>, the bus bar <NUM>, and the transparent conductor bridge <NUM> are spaced laterally inwardly from the spacer <NUM> relative to the adjacent edge <NUM> of the selected pane <NUM> (<FIG>). Skilled artisans will appreciate that that alternative spacer arrangements can be provided, and that the described embodiments are by no means limiting.

Claim 1:
A multiple-pane insulating glazing unit (<NUM>) comprising two panes (<NUM>, <NUM>) and a between-pane space, the between-pane space being located between the two panes, wherein a desired surface (<NUM>) of a selected one of the two panes bears a coating (<NUM>) comprising both a transparent conductive oxide film (<NUM>) and an overcoat film (<NUM>), the overcoat film being located over the transparent conductive oxide film, the multiple-pane insulating glazing unit further comprising a bus bar (<NUM>) and a transparent conductor bridge (<NUM>) each located over the desired surface, the bus bar being spaced apart from the coating, the bus bar being connected electrically to the transparent conductive oxide film by virtue of the transparent conductor bridge extending from the bus bar to a top surface (<NUM>) of the overcoat film, and the transparent conductor bridge overlying both the bus bar and coating.