Patent Publication Number: US-11035168-B2

Title: Method and apparatus for an insulating glazing unit and compliant seal for an insulating glazing unit

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 15/141,485 filed Apr. 28, 2016, which is a continuation of U.S. application Ser. No. 13/464,951 filed May 4, 2012, which claims the benefit of U.S. provisional application No. 61/482,701 filed on May 5, 2011. application Ser. Nos. 15/141,485, 13/464,951 and 61/482,701 are incorporated-by-reference herein in their entirety. 
    
    
     This invention was made with government support under Contract No. DE-EE0004024 awarded by the Department of Energy. The Government has certain rights in this invention. 
    
    
     TECHNICAL FIELD 
     The following disclosure relates generally to insulating glazing apparatus (including insulated glazing units and vacuum insulating glazing units) having spaced-apart glazing panes. More specifically, it relates to insulating glazing apparatus having compliant seals for providing an airtight seal between the spaced-apart panes of an insulating glazing apparatus, apparatus comprising such seals, and methods for manufacture of same. 
     BACKGROUND 
     Insulating glazing units (IGUs) comprise two or more glass lites (panes) separated by one or more volumes which are sealed and then filled with an insulating gas mixture and/or partially evacuated to create at least one insulating cavity. Vacuum insulating glazing units (VIGUs) comprise two or more glass lites separated by one or more volumes which are sealed and evacuated to create at least one insulating vacuum cavity. The volume between the lites is sealed around its perimeter (or edge) by an edge seal. The edge seal is a part (or assembly of parts) that is bonded to one lite, spans across the gap between the two lites, and is bonded to the second lite. At any time after the IGU/VIGU has been assembled, the first lite may have a difference in temperature from the second lite. The temperature difference leads to differential expansion or contraction and, therefore, relative motion between the glass lites. A rigid edge seal strongly resists the relative motion between the lites, thereby creating a buildup of thermal stresses within the IGU/VIGU assembly. A need therefore exists, for a compliant edge seal that permits relative motion between the glass lites, thereby reducing the stresses created in the IGU/VIGU assembly due to thermal distortions. Minimization of the thermal stresses is desirable to prevent IGU/VIGU failure in climates where significant temperature differences between adjacent lites are encountered. 
     The relative motion between adjacent lites in any region along the perimeter of the IGU/VIGU can be broken into two components, both of which are oriented parallel to the planes of the lites. The relative motion normal to the planes of the lites is relatively small, and is therefore not included. The two components parallel to the planes of the lites are herein defined relative to the edge seal. The motion component oriented along the length of any portion of the edge seal is herein defined as the longitudinal component and the motion component oriented at a right angle (i.e., normal) to the longitudinal component and parallel to the planes of the lites is herein defined as the lateral component. At any given point around the perimeter of the IGU/VIGU assembly, there are generally longitudinal and lateral components of relative motion between the lites at any given time. The relative motion is believed to be largest near the corners in the case of a rectangular IGU/VIGU. A need therefore exists, for an edge seal that offers compliance in both the longitudinal and lateral directions. 
     The edge seal for an IGU/VIGU is generally constructed of a thin sheet of material. For VIGUs, the edge seal must be hermetic, and thus is generally constructed of a thin hermetic sheet of material. The sheet material is formed in some fashion around the edge of the IGU/VIGU. The geometry of the edge seal dictates that relative motion of the lites in the longitudinal direction is largely accommodated by a shearing action of the edge seal while relative motion of the lites in the lateral direction is largely accommodated by bending of the edge seal material. Thin sheet material is relatively rigid in response to a shearing action and relatively compliant in response to a bending action. As a result, longitudinal (shear) compliance is generally more difficult to obtain than lateral (bending) compliance in an IGU/VIGU edge seal when the edge seal is formed of a thin sheet of material. A need therefore exists, for an edge seal having improved longitudinal (shear) compliance. 
     SUMMARY 
     This disclosure describes edge seals for IGUs and/or VIGUs that are highly compliant in response to longitudinal and lateral components of relative motion between the two adjacent lites attached to one another through the edge seal. 
     In one embodiment, an insulating glazing unit comprises a first lite formed from a hermetic transparent material and a second lite formed from a hermetic transparent material and spaced-apart from the first lite to define an insulating cavity therebetween. An edge seal is hermetically bonded between the respective edges of the first lite and the second lite, the edge seal being formed from a hermetic material. The edge seal includes a compliant region having a surface formed in a three-dimensional pattern. 
     In another embodiment, an insulating glazing unit comprises a first lite formed from a hermetic transparent material and a second lite formed from a hermetic transparent material that is spaced-apart from the first lite to define an insulating cavity therebetween. An edge seal assembly includes an outer member, a first inner member and a second inner member, each of the outer member, first inner member and second inner member being formed of hermetic materials. An inner surface of first inner member is hermetically bonded to an outer edge of the first lite, an inner surface of second inner member is hermetically bonded to an outer edge of the second lite, the outer surface of the first inner member is hermetically bonded to a first inner edge of the outer member, and the outer surface of the second inner member is hermetically bonded to a second inner edge of the outer member. The edge seal includes a compliant region having a surface formed in a three-dimensional pattern. 
     In another embodiment, a method of manufacturing an insulating glazing unit is provided. The method comprises the following steps: a) providing a length of first inner member, wrapping the length of inner member around a first lite, cutting and joining the first inner member to itself at the location where it would otherwise overlap itself, and joining the first inner member to the edge of the first lite where it is coincident after wrapping; b) providing a length of second inner member, wrapping the length of inner member around a second lite, cutting and joining the second inner member to itself at the location where it would otherwise overlap itself, and joining the second inner member to the edge of the second lite where it is coincident after wrapping; c) positioning the first lite and the second lite in a spaced-apart configuration forming an insulating cavity; d) providing a length of an outer member having a compliant region with a three-dimensional surface pattern, wrapping the outer member around the assembly of first and second lites and first and second inner members, cutting and joining the outer member to itself at the location where it would otherwise overlap itself and joining the outer member to each one of the inner members to form a pair of continuous seals; and e) evacuating the insulating cavity and sealing the insulating cavity. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding, reference is now made to the following description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a cross-sectional perspective view of a VIGU/IGU having an edge seal; 
         FIG. 2  is a cross-sectional perspective view of a VIGU/IGU having an edge seal with a compliant region including a three-dimensional pattern imprinted thereon in accordance with another embodiment; 
         FIGS. 3 a  and 3 b    are enlarged perspective views of the compliant region of the edge seal of  FIG. 2 , wherein  FIG. 3 a    shows the unstressed (un-deformed) state and  FIG. 3 b    shows the shear (i.e., longitudinally) deformed shape; 
         FIGS. 4 a  and 4 b    are perspective and side views, respectively, of the compliant region of  FIG. 2 ; 
         FIGS. 5 a  and 5 b    are perspective and side views, respectively, of an alternative three-dimensional pattern for a compliant region in accordance with another embodiment; 
         FIGS. 6 a  and 6 b    are perspective and side views, respectively, of an alternative three-dimensional pattern for a compliant region in accordance with yet another embodiment; 
         FIGS. 7 a , 7 b  and 7 c    are cross-sectional perspective views of another VIGU/IGU in accordance with an apparatus and a method in accordance with additional embodiments; 
         FIG. 8  is a perspective view of the corner of a VIGU/IGU similar to that shown in  FIGS. 7 a , 7 b    and  7   c;    
         FIGS. 9 a  and 9 b    are cross-sectional perspective views of a VIGU/IGU in accordance with another embodiment,  FIG. 9 a    showing the edge seal with the three-dimensional pattern omitted for purposes of illustration and  FIG. 9 b    showing the edge seal with the location of the three-dimensional pattern indicated by checkerboard markings; 
         FIGS. 10 a  and 10 b    are cross-sectional perspective views of a VIGU/IGU in accordance with another embodiment,  FIG. 10 a    showing the edge seal with the three-dimensional pattern omitted for purposes of illustration and  FIG. 10 b    showing the edge seal with the location of the three-dimensional pattern indicated by checkerboard markings; 
         FIGS. 11 a  and 11 b    are cross-sectional perspective views of a VIGU/IGU in accordance with another embodiment,  FIG. 11 a    showing the edge seal with the three-dimensional pattern omitted for purposes of illustration and  FIG. 11 b    showing the edge seal with the location of the three-dimensional pattern indicated by checkerboard markings; 
         FIGS. 12 a  and 12 b    are cross-sectional perspective views of a VIGU/IGU in accordance with another embodiment,  FIG. 12 a    showing the edge seal with the three-dimensional pattern omitted for purposes of illustration and  FIG. 12 b    showing the edge seal with the location of the three-dimensional pattern indicated by checkerboard; 
         FIGS. 13 a , 13 b , 13 c  and 13 d    are cross-sectional side views of a VIGU/IGU in accordance with another embodiment having a single piece edge seal;  FIG. 13 a    showing the edge seal after formation of the three-dimensional pattern,  FIG. 13 b    showing the edge seal positioned adjacent the two glass panes for a first bond,  FIG. 13 c    showing the edge seal positioned adjacent the two glass panes for a second bond and  FIG. 13 d    showing the completed VIGU/IGU; 
         FIGS. 14 a , 14 b , 14 c  and 14 d    are cross-sectional side views of a VIGU/IGU in accordance with an alternative embodiment having a single piece edge seal;  FIG. 14 a    showing the edge seal after formation of the three-dimensional pattern,  FIG. 14 b    showing the edge seal positioned adjacent the two glass panes for a first bond,  FIG. 14 c    showing the edge seal positioned adjacent the two glass panes for a second bond and  FIG. 14 d    showing the completed VIGU/IGU; 
         FIG. 15  is a perspective view of a corner portion of a VIGU/IGU having large-radius corners showing one configuration of an edge seal in the corner region; 
         FIG. 16  is a perspective view of a corner portion of another VIGU/IGU having large-radius corners showing an alternative configuration of an edge seal in the corner region; 
         FIG. 17  is a perspective view of a corner portion of a VIGU/IGU having sharp-radius corners showing one configuration of an edge seal in the corner region; 
         FIG. 18  is a perspective view of a corner portion of another VIGU/IGU having sharp-radius corners showing an alternative configuration of an edge seal in the corner region; and 
         FIGS. 19 a , 19 b , 19 c , 19 d  and 19 e    are perspective views illustrating the fabrication of a metal edge band and its attachment to a glass pane in accordance with another embodiment;  FIG. 19 a    showing the metal edge band being extended from a supply reel,  FIG. 19 b    showing the fabrication of the edge seal end,  FIG. 19 c    showing the welding of the edge band;  FIG. 19 d    showing the stretching/positioning of the edge band and  FIG. 19 e    showing the glass pane with the edge band attached. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, wherein like reference numbers are used herein to designate like elements throughout, the various views and embodiments of a method and apparatus for an insulating glazing unit and compliant seal for an insulating glazing unit are illustrated and described, and other possible embodiments are described. The figures are not necessarily drawn to scale, and in some instances the drawings have been exaggerated and/or simplified in places for illustrative purposes only. One of ordinary skill in the art will appreciate the many possible applications and variations based on the following examples of possible embodiments. 
     For purposes of this application, the term “hermetic” as applied to a material or a seal shall mean (unless otherwise specifically denoted) that, when used to form a sealed cavity and subjected to a pressure differential of approximately one atmosphere (i.e., in air), the material or seal has a permeability or “leak rate” that is sufficiently low such that the internal pressure within the sealed cavity changes by less than 1 mtorr (i.e., 1×10 −3  torr) over a period of at least ten years, and preferably over a period of 30-40 years. For example, if the initial pressure within the sealed cavity is 1×10 −4  torr, the materials and/or seals forming the cavity would be considered hermetic for ten years if the pressure within the sealed cavity after ten years is still less than 1.1×10 −3  torr. In another example, if the initial pressure within the sealed cavity is 5×10 −5  torr, the materials and/or seals forming the cavity would be considered hermetic for thirty years if the pressure within the sealed cavity after thirty years is less than 1.05×10 −3  torr. 
     Referring now to  FIG. 1 , there is illustrated a cross-sectional view of a vacuum insulating glazing unit (VIGU). VIGU  100  comprises a first lite  101  and a second lite  102 . The lites are formed from a hermetic transparent material, preferably glass. Lites  101  and  102  are spaced-apart from one another, defining an insulating cavity  103  therebetween. A plurality of stand-off members or “spacers” (not shown) may be positioned in the cavity  103  between the lites  101  and  102  to maintain separation of the lites. The stand-off members may be affixed to one or both of the lites  101 ,  102  or held in place by other means, e.g., suspended on fibers or held in position by friction between the lites. The stand-off members may be formed of glass, ceramic, metal or other materials having high compression strength and little or no out-gassing. An edge seal  104  is hermetically bonded between the respective edges of first lite  101  and second lite  102  using a hermetic joining material  105 . In the embodiment shown, the edge seal  104  is bonded to the upper surface of first lite  101  and to the lower surface of second lite  102 . In an alternative embodiment, the edge seal  104  is hermetically bonded to the upper front edge of first lite  101  (e.g., in the area denoted  105   a ) and to the lower front edge of second lite  102  (e.g., in the area denoted  105   b ). In another alternative embodiment, the edge seal  104  is hermetically bonded directly to the lites  101  and  102  such that joining material  105  is not necessary. The edge seal  104  is formed from a hermetic material, preferably a foil or thin sheet of metal or metal alloy. Lateral motion of lite  101  relative to lite  102  is denoted by the arrow  106 , and longitudinal motion of lite  101  relative to lite  102  is denoted by the arrow  107 . In a VIGU, the insulating cavity is evacuated to a vacuum. In one embodiment, the hermetic materials are hermetic for at least ten years. In another embodiment, the hermetic materials are hermetic for at least thirty years. In yet another embodiment, the hermetic materials are hermetic for at least forty years. In a preferred embodiment, the insulating cavity is evacuated to a vacuum within the range from 1×10 −6  torr to 1×10 −3  torr. Alternatively, an insulating glazing unit (IGU) (not shown) may be constructed in a substantially identical fashion, except the materials and seals need not be hermetic and the atmosphere within the insulating cavity is a partial vacuum and/or filled with an insulating gas or gas mixture. The evacuation, partial evacuation or (in the case of IGUs) filling with insulating gasses of the insulating cavity may be achieved by sealing the insulating cavity while the VIGU/IGU is in, respectively, a vacuum chamber, a partial vacuum chamber or a gas-filled chamber. Alternatively, the evacuation and/or filling may be achieved after the insulating cavity has been sealed via an evacuation port (also called a “pinch-off tube” or “pump-out tube”) in communication with the insulating cavity. 
     Referring now to  FIG. 2 , there is illustrated a cross-sectional view of a VIGU in accordance with one embodiment. Except as noted below, VIGU  200  is generally similar to VIGU  100  shown in  FIG. 1 , comprising a first lite  201 , a second lite  202 , an insulating cavity  203  therebetween and an edge seal  204  bonded between the respective edges of first lite  201  and second lite  202  using a hermetic joining material  205 . The lites  201  and  202  are formed from a hermetic transparent material, preferably glass. A plurality of stand-off members (not shown) may be positioned in the cavity  203  between the lites  201  and  202  to maintain separation of the lites. The stand-off members may be affixed to one or both of the lites  201 ,  202  or held in place by other means. The stand-off members may be formed of glass, ceramic, metal or other materials having high compression strength and little or no out-gassing. The edge seal  204  is formed from a hermetic material, preferably a foil or thin sheet of metal or metal alloy. In the embodiment shown, the edge seal  204  is bonded to the upper surface of first lite  201  and to the lower surface of second lite  202 . In an alternative embodiment, the edge seal  204  is hermetically bonded to the upper front edge of first lite  201  (e.g., in the area denoted  205   a ) and to the lower front edge of second lite  202  (e.g., in the area denoted  205   b ). In another alternative embodiment, the edge seal  204  is hermetically bonded directly to the lites  201  and  202  such that joining material  205  is not necessary. 
     The edge seal  204  of VIGU  200  includes a compliant region  208  having a surface formed in a three-dimensional pattern. The three-dimensional pattern of the compliant region  208  may be formed by imprinting, stamping, embossing, roll-forming or other known methods of metal-forming. The compliant region  208  provides greater compliance to the edge seal  204  to accommodate relative motion between the lites  201  and  202  in the lateral direction (denoted by arrow  206 ) and/or in the longitudinal directions (denoted by arrow  207 ), as compared to edge seals without the three-dimensional compliant region. This greater compliance may result in a reduction of thermally-induced stress in the lites  201  and  202 , e.g., in the area where the edge seal  204  is bonded to the lites, as well as in the compliant edge seal itself. In the embodiment illustrated in  FIG. 2 , the compliant region  208  of the edge seal is bounded on two sides by relatively flat, longitudinally-oriented regions  209  of the edge seal lying substantially in the same plane as the compliant region. In a VIGU, the insulating cavity is evacuated to a vacuum. In one embodiment, the hermetic materials are hermetic for at least ten years. In another embodiment, the hermetic materials are hermetic for at least thirty years. In yet another embodiment, the hermetic materials are hermetic for at least forty years. In a preferred embodiment, the insulating cavity is evacuated to a vacuum within the range of 1×10 −6  torr to 1×10 −3  torr. Alternatively, an insulating glazing unit (IGU) (not shown) may be constructed in a substantially identical fashion, except the materials and seals need not be hermetic and the atmosphere within the insulating cavity is a partial vacuum and/or filed with an insulating gas or gas mixture. As describe above, the evacuation, partial evacuation or (in the case of IGUs) filling with insulating gasses of the insulating cavity may be achieved at the time of sealing the insulating cavity by sealing it while the VIGU/IGU is in, respectively, a vacuum chamber, a partial vacuum chamber or a gas-filled chamber. Alternatively, the evacuation and/or filling of the insulating cavity may be achieved after the insulating cavity has been sealed via an evacuation port. 
     Referring now to  FIGS. 3 a  and 3 b   , there is illustrated an enlarged portion of the compliant region  208  of edge seal  204 , showing how a sheet material  300  having a three-dimensional imprinted pattern accommodates shear deformation largely through bending of the three-dimensional sheet material rather than extension (i.e., overall stretching) of the sheet material. In other words, as the three-dimensional sheet material is subjected to stresses, the three-dimensional contours of the sheet material can bend in localized areas (e.g., at the junctions between the “hills” and “valleys” of the pattern) from their initial configuration into a longer, flatter configuration in regions subjected to tension and into a shorter, more contoured configuration in regions subjected to compression. 
     Specifically,  FIG. 3 a    shows compliant region  208  in a non-deformed (i.e., unloaded) shape  301 , whereas  FIG. 3 b    shows compliant region  208  being deformed into a shear-deformed shape  302  by the application of loads in opposite directions (denoted by arrows  303 ). In this embodiment, the arrows  303  indicate a loading direction consistent with relative motion between lites  201  and  202  in the longitudinal direction  207 ; however, loading in the lateral direction or in both directions is possible. It will be appreciated that the contour lines appearing in  FIGS. 3 a  and 3 b    are for purposes of illustration, i.e., to allow visualization of the surface contours of compliant region  208 , and do not represent actual indicia or structures on the sheet material  300 . If for use in a VIGU, the sheet material  300  is formed from a hermetic material, preferably a foil or thin sheet of metal or metal alloy. In one embodiment, the hermetic materials are hermetic for at least ten years. In another embodiment, the hermetic materials are hermetic for at least thirty years. In yet another embodiment, the hermetic materials are hermetic for at least forty years. If for use in an IGU, the sheet material  300  need not be a hermetic material. 
     Referring now to  FIGS. 4 a  and 4 b   , there is further illustrated a sheet material  400  having a three-dimensional imprinted pattern  401  suitable for use on the compliant region  208  of edge seal  204 . Specifically,  FIG. 4 a    is an isometric view of the sheet material  400  and  FIG. 4 b    is a side view of the sheet material  400  having the same pattern  401 . 
     Referring now to  FIGS. 5 a  and 5 b   , there is illustrated an alternative sheet material  500  having a three-dimensional imprinted pattern  501  suitable for use on the compliant region  208  of edge seal  204 . Specifically,  FIG. 5 a    is an isometric view of the sheet material  500  and  FIG. 5 b    is a side view of the sheet material  500  having the same pattern  501 . 
     Referring now to  FIGS. 6 a  and 6 b   , there is illustrated another alternative sheet material  600  having a three-dimensional imprinted pattern  601  suitable for use on the compliant region  208  of edge seal  204 . Specifically,  FIG. 6 a    is an isometric view of the sheet material  600  and  FIG. 6 b    is a side view of the sheet material  600  having the same pattern  601 . 
     Referring now to  FIGS. 7 a , 7 b  and 7 c   , there is illustrated a VIGU/IGU in accordance with another embodiment and a method of obtaining longitudinal compliance using a three-dimensional patterned edge seal in accordance with yet another embodiment. Specifically,  FIG. 7 a    shows a VIGU/IGU  700  after assembly,  FIG. 7 b    is an exploded diagram of the components of VIGU/IGU  700  prior to assembly, and  FIG. 7 c    shows the VIGU/IGU  700  at an intermediate stage during the assembly process. The VIGU/IGU  700  includes a first lite  701  and second lite  702  spaced apart to define an insulating (e.g., vacuum, partial vacuum or insulating gas-filled) cavity  703  disposed therebetween. A plurality of stand-off members (not shown) may be positioned in the cavity  703  between the lites  701  and  702  to maintain separation of the lites. The stand-off members may be affixed to one or both of the lites  701 ,  702  or held in place by other means, e.g., suspended on fibers or held in position by friction between the lites. The lites  701  and  702  are formed from a hermetic transparent material, preferably glass. The stand-off members may be formed of glass, ceramic, metal or other materials having high compression strength and little or no out-gassing. As further described below, an edge seal assembly  705  having a compliant portion is bonded between the respective edges of the two lites  701  and  702 . 
     As best seen in  FIG. 7 b   , the edge seal assembly  705  includes an outer member  704 , a first inner member  709  and a second inner member  710 . An inner surface  711  of first inner member  709  is bonded to an outer edge  713  of the first lite  701 , and an inner surface  712  of second inner member  710  is bonded to an outer edge  714  of the second lite  702 . In the case of a VIGU, the bonds between inner member inner surfaces  711 ,  712  and respective lite outer edges  713 ,  714  are hermetic. The outer surface  715  of the first inner member  709  is bonded to a first inner edge  717  of the outer member  704 , and the outer surface  716  of the second inner member  710  is bonded to a second inner edge  718  of the outer member. In the case of a VIGU, the bonds between inner member outer surfaces  715 ,  716  and respective outer member inner edges  717 ,  718  are hermetic. The outer member  704  includes a compliant region  720  having a surface formed in a three-dimensional pattern, e.g., the three-dimensional patterns previously described in connection with  FIGS. 2, 3   a ,  3   b ,  4   a ,  4   b ,  5   a ,  5   b ,  6   a  and/or  6   b . Preferably, some or all of the edge seal elements  704 ,  709  and  710  are spoolable parts, meaning they may be stored in a rolled-up state on a spool until needed for assembly. 
     In a VIGU, the insulating cavity is evacuated to a vacuum. In one embodiment, the hermetic materials are hermetic for at least ten years. In another embodiment, the hermetic materials are hermetic for at least thirty years. In yet another embodiment, the hermetic materials are hermetic for at least forty years. In a preferred embodiment, the insulating cavity is evacuated to a vacuum within the range of 1×10 −6  torr to 1×10 −3  torr. Alternatively, an insulating glazing unit (IGU) (not shown) may be constructed in a substantially identical fashion, except the materials and seals need not be hermetic and the atmosphere within the insulating cavity is a partial vacuum and/or filed with an insulating gas or gas mixture. As describe above, the evacuation, partial evacuation or (in the case of IGUs) filling with insulating gasses of the insulating cavity may be achieved at the time of sealing the insulating cavity by sealing it while the VIGU/IGU is in, respectively, a vacuum chamber, a partial vacuum chamber or a gas-filled chamber. Alternatively, the evacuation and/or filling of the insulating cavity may be achieved after the insulating cavity has been sealed via a pinch-off tube or pump-out tube. 
     As best seen in  FIG. 7 c   , after bonding the inner surface  711  of first inner member  709  to the outer edge  713  of the first lite  701 , the inner surface  712  of second inner member  710  to the outer edge  714  of the second lite  702 , the outer surface  715  of the first inner member  709  to the first inner edge  717  of the outer member  704 , and the outer surface  716  of the second inner member  710  to the second inner edge  718  of the outer member, the flange portions  721 ,  722  of the edge seal assembly  705  may be folded back approximately 90 degrees (as denoted by arrows  723 ) such that they lie against the outer surfaces of the lites  701 ,  702 . In the case where the flange portions  721 ,  722  are folded such that they lie against the outer surfaces of the lites  701 ,  702 , it is preferred that the flanges are also joined to the surfaces of the lites, e.g., by adhesive, solder or other adherent materials. Note, however, this joining of the flanges to the lites need not be hermetic. 
     As seen in  FIGS. 7 a , 7 b  and 7 c   , one method of assembling a VIGU/IGU  700  is to take the following numbered steps: 1) Unload (e.g., unspool if stored on a spool) a length of first inner member  709 ; wrap the length of inner member  709  around first lite  701 , cut and join member  709  to itself at the location where it would otherwise overlap itself; and join member  709  to the edge  713  of lite  701  where it is coincident after wrapping. 2) Unload (e.g., unspool if stored on a spool) a length of second inner member  710 ; wrap the length of inner member  710  around second lite  702 , cut and join member  710  to itself at the location where it would otherwise overlap itself; and join member  710  to the edge  714  of lite  702  where it is coincident after wrapping. 3) Position first lite  701  and second lite  702  in a spaced-apart configuration forming the cavity  703  and including any other assembly parts such as spacers (not shown) between the lites  701 ,  702 . 4) Unload (e.g., unspool if stored on a spool) a length of outer member  704  having a compliant region  720  with a three-dimensional surface pattern; wrap the outer member  704  around the assembly of lites  701 ,  702  and inner members  709 ,  710 ; cut and join outer member  704  to itself at the location where it would otherwise overlap itself and join outer member  704  to one of the inner members  709  and  710  where it is coincident after wrapping. 5) Place the assembly in a vacuum chamber to evacuate the vacuum cavity  703  and seal the vacuum cavity by joining outer member  704  to the remaining inner member  709  or  710  where it is coincident. In an alternative method, step 5) above may be replaced with step 5a) as follows: 5a) Seal the vacuum cavity by joining outer member  704  to the remaining inner member  709  or  710  where it is coincident; then evacuating the vacuum cavity  703  via an evacuation port; and then sealing the evacuation port. 
     Referring now to  FIG. 8 , there is illustrated a VIGU/IGU assembly  800  similar to the VIGU/IGU  700  depicted in  FIGS. 7 a , 7 b  and 7 c   , but showing how the compliant edge-seal  705  with compliant, three-dimensional patterned region  720  could be wrapped around the corners of the VIGU/IGU. The first and second inner members  709 ,  710  are first joined, respectively, to the first and second lites  701 ,  702  (including the corners of the lites) as previously described. Next, the outer member  704  is joined to the inner members  709 ,  710  (including around the corners) as previously described. Finally, the edge seal flanges  721 ,  722  are folded down such that they lie against the outer surfaces of the lites  701 ,  702  and then joined to the surfaces of the lites as previously described. It will be appreciated that the portions of the flanges  721 ,  722  wrapped around the corners of the lites may incur creases as they are folded back against the surface of the lites  701 ,  702 , however, these creases do not compromise the sealing function of the seal assembly  705  as the joint created between the respective sealing surfaces  711 ,  712  of inner members  709 ,  710  and the edges  713 ,  714  of the lites prior to folding remains a continuous joint free of creasing. 
     Referring now to  FIGS. 9 a  and 9 b   , there is illustrated a VIGU/IGU  900  with an alternative edge seal configuration  905  that can accommodate the disclosed method of obtaining longitudinal compliance through the use of a three-dimensional imprinted pattern. Specifically,  FIG. 9 a    shows the edge seal  905  with the three-dimensional pattern of the compliant region  920  not shown for purposes of clearly illustrating the seal configuration; whereas  FIG. 9 b    shows the same VIGU/IGU  900  with the location of the compliant region  920  indicated by use of a checkerboard pattern. Seal  905  is a bellows type seal. The compliant region  920  may use any of the three-dimensional patterns previously described herein. 
     Referring now to  FIGS. 10 a  and 10 b   , there is illustrated a VIGU/IGU  1000  with an alternative edge seal configuration  1005  that can accommodate the disclosed method of obtaining longitudinal compliance through the use of a three-dimensional imprinted pattern. Specifically,  FIG. 10 a    shows the edge seal  1005  with the three-dimensional pattern of the compliant region  1020  not shown for purposes of clearly illustrating the seal configuration; whereas  FIG. 10 b    shows the same VIGU/IGU  1000  with the location of the compliant region  1020  indicated by use of a checkerboard pattern. Seal  1005  is a flat seal. The compliant region  1020  may use any of the three-dimensional patterns previously described herein. 
     Referring now to  FIGS. 11 a  and 11 b   , there is illustrated a VIGU/IGU  1100  with an alternative edge seal configuration  1105  that can accommodate the disclosed method of obtaining longitudinal compliance through the use of a three-dimensional imprinted pattern. Specifically,  FIG. 11 a    shows the edge seal  1105  with the three-dimensional pattern of the compliant region  1120  not shown for purposes of clearly illustrating the seal configuration; whereas  FIG. 11 b    shows the same VIGU/IGU  1100  with the location of the compliant region  1120  indicated by use of a checkerboard pattern. Seal  1105  is similar to the embodiment described in connection with  FIGS. 7 a , 7 b  and 7 c   , except there is an extra convolution  1110  in the geometry which may further increase longitudinal compliance and further increase the thermal resistance through the edge seal. The compliant region  1120  may use any of the three-dimensional patterns previously described herein. 
     Referring now to  FIGS. 12 a  and 12 b   , there is illustrated a VIGU/IGU  1200  with an alternative edge seal configuration  1205  that can accommodate the disclosed method of obtaining longitudinal compliance through the use of a three-dimensional imprinted pattern. Specifically,  FIG. 12 a    shows the edge seal  1205  with the three-dimensional pattern of the compliant region  1220  not shown for purposes of clearly illustrating the seal configuration; whereas  FIG. 12 b    shows the same VIGU/IGU  1200  with the location of the compliant region  1220  indicated by use of a checkerboard pattern. Seal  1205  is another type of flat seal. The compliant region  1220  may use any of the three-dimensional patterns previously described herein. 
     Referring now to  FIGS. 13 a , 13 b , 13 c  and 13 d   , there is illustrated a VIGU/IGU  1300  having a one-piece edge seal in accordance with another embodiment, and a method of producing a VIGU/IGU having a one-piece edge seal in accordance with yet another embodiment. Specifically,  FIG. 13 a    shows a cross-sectional view of a one-piece edge seal  1305  comprising a central compliant portion  1320  disposed between two lateral portions  1322 . The edge seal  1305  may be formed from a hermetic material, preferably a foil or thin sheet of metal or metal alloy that can be soldered and/or welded. Preferably, the material of the edge seal  1305  is spoolable, i.e., it may be stored in a rolled-up state on a spool (or reel) until needed for assembly. 
     The compliant portion  1320  of the edge seal  1305  may have a surface formed in a three-dimensional pattern, e.g., the three-dimensional patterns previously described in connection with  FIGS. 2, 3   a ,  3   b ,  4   a ,  4   b ,  5   a ,  5   b ,  6   a  and/or  6   b . Each lateral portion  1322  includes a proximal section  1324  disposed adjacent to the central compliant portion  1320  and a distal section  1326  disposed on the opposite side of the proximal section from the compliant portion. 
     Referring now to  FIG. 13 b   , the one-piece edge seal  1305  is positioned so that the compliant portion  1320  lies adjacent a first lite  1301  and second lite  1302 , which are spaced apart to define an insulating cavity  1303  disposed therebetween (which will later be evacuated). In particular, the compliant portion  1320  is aligned with edges  1313  and  1314 , respectively, of the lites  1301  and  1302 . The lites  1301  and  1302  are formed from a hermetic transparent material, preferably glass. A plurality of stand-off members  1325  ( FIG. 13 d   ) may be positioned in the cavity  1303  between the lites  1301  and  1302  to maintain separation of the lites. For purposes of illustration, the stand-off members  1325  are not shown in  FIGS. 13 b  and 13 c   . The stand-off members may be affixed to one or both of the lites  1301 ,  1302  or held in place by other means, e.g., suspended on fibers or held in position by friction between the lites. The stand-off members  1325  may be formed of glass, ceramic, metal or other materials having high compression strength and little or no out-gassing. 
     Referring still to  FIG. 13 b   , each lateral portion  1322  of the edge seal  1305  is first folded between the proximal section  1324  and the distal section  1326  to bring at least a first part of the distal section directly adjacent to the edges  1313  and  1314  of the lites  1301  and  1302 , i.e., interposed between the edges  1313 ,  1314  and the compliant portion  1320 . As further described herein, each first part of the distal section  1326  of the edge seal  1305  is then bonded to the respective adjacent edge  1313 ,  1314  of the lites  1301 ,  1302  to form a hermetic bond  1330  ( FIG. 13 d   ). The hermetic bond  1330  must be capable of blocking the passage of gasses into the cavity  1303  to maintain the required hermeticity, but it is not required to withstand any significant structural loads arising from the compliant portion  1320  of the edge seal  1305 . In some embodiments, the hermetic bond  1330  comprises a solder. In preferred embodiments, the solder is a metallic solder, however, in other embodiments the solder may be a solder glass. 
     Referring now to  FIG. 13 c   , after hermetically bonding the first part of each distal section  1326  to the edges  1313 ,  1314 , the lateral portion  1322  is folded a second time such that the remaining parts of the distal section lie against the respective faces  1327 ,  1328  of lites  1301 ,  1302  and the proximal portions  1324  lie substantially parallel to the faces. As further described herein, each remaining part of the distal section  1326  of the edge seal  1305  is then bonded to the respective adjacent face  1327 ,  1328  to form a structural bond  1332  ( FIG. 13 d   ). The structural bond  1332 , unlike the hermetic bond  1330 , need not be capable of blocking the passage of gasses into the cavity  1303 . Instead, the structural bond  1332  must withstand the structural loads arising from the compliant portion  1320  and prevent the transmission of any significant structural loads to the hermetic bond  1330 . Accordingly, the structural bond  1332  is always interposed along the edge seal  1305  between the compliant portion  1320  and the hermetic bond  1330  (i.e., when considering the edge seal  1305  as extending continuously from one distal end to the opposite distal end). In some embodiments, the structural bond  1332  may comprise one of a thermoset or a thermoplastic. In preferred embodiments, the structural bond  1332  may comprise one or more of acrylic, epoxy, urethane, polyester, polyimide, phenolic, polyamide, cyanoacrylate, polyacrylate, and polyvinyl acetate. 
     Referring now to  FIG. 13 d   , the VIGU  1300  is shown, including the lites  1301 ,  1302 , edge seal  1305  and stand-off members  1325  (for purposes of illustration, only an end portion of the complete VIGU is shown). The insulating cavity  1303  is evacuated to a vacuum, typically through an evacuation port (not shown) following forming the hermetic bonds  1330  and the structural bonds  1332 . In one embodiment of the VIGU  1300 , the hermetic materials, including the hermetic bond  1330 , are hermetic for at least ten years. In another embodiment, the hermetic materials, including the hermetic bond  1330 , are hermetic for at least thirty years. In yet another embodiment, the hermetic materials, including the hermetic bond  1330 , are hermetic for at least forty years. In a preferred embodiment, the insulating cavity  1303  is evacuated to a vacuum within the range of 1×10 −6  torr to 1×10 −3  torr. Alternatively, an insulating glazing unit (IGU) (not shown) may be constructed in a substantially identical fashion, except the materials and seals need not be hermetic and the atmosphere within the insulating cavity is a partial vacuum and/or filed with an insulating gas or gas mixture. As describe above, the evacuation, partial evacuation or (in the case of IGUs) filling with insulating gasses of the insulating cavity  1303  may be achieved at the time of sealing the insulating cavity by sealing it while the VIGU/IGU  1300  is in, respectively, a vacuum chamber, a partial vacuum chamber or a gas-filled chamber. Alternatively, the evacuation and/or filling of the insulating cavity  1303  may be achieved after the insulating cavity has been sealed via an evacuation tube. 
     Referring now to  FIGS. 14 a , 14 b , 14 c  and 14 d   , there is illustrated a VIGU/IGU  1400  having an alternative one-piece edge seal in accordance with another embodiment, and a method of producing a VIGU/IGU having an alternative one-piece edge seal in accordance with yet another embodiment. Specifically,  FIG. 14 a    shows a cross-sectional view of a one-piece edge seal  1405  comprising a central compliant portion  1420  disposed between two lateral portions  1422 . The edge seal  1405  may be formed from a hermetic material, preferably a foil or thin sheet of metal or metal alloy that can be soldered and/or welded. Preferably, the material of the edge seal  1405  is spoolable, i.e., it may be stored in a rolled-up state on a spool (or reel) until needed for assembly. 
     The compliant portion  1420  of the edge seal  1405  may have a surface formed in a three-dimensional pattern, e.g., the three-dimensional patterns previously described in connection with  FIGS. 2, 3   a ,  3   b ,  4   a ,  4   b ,  5   a ,  5   b ,  6   a  and/or  6   b . Each lateral portion  1422  includes a proximal section  1424  disposed adjacent to the central compliant portion  1420  and a distal section  1426  disposed on the opposite side of the proximal section from the compliant portion. 
     Referring now to  FIG. 14 b   , the one-piece edge seal  1405  is positioned so that the compliant portion  1420  lies adjacent a first lite  1401  and second lite  1402 , which are spaced apart to define an insulating cavity  1403  disposed therebetween. In particular, the compliant portion  1420  is aligned with edges  1413  and  1414 , respectively, of the lites  1401  and  1402 . The lites  1401  and  1402  are formed from a hermetic transparent material, preferably glass. A plurality of stand-off members  1425  ( FIG. 14 d   ) may be positioned in the cavity  1403  between the lites  1401  and  1402  to maintain separation of the lites. The stand-off members may be affixed to one or both of the lites  1401 ,  1402  or held in place by other means, e.g., suspended on fibers or held in position by friction between the lites. The stand-off members  1425  may be formed of glass, ceramic, metal or other materials having high compression strength and little or no out-gassing. 
     Referring still to  FIG. 14 b   , each lateral portion  1422  of the edge seal  1405  is first folded between the proximal section  1424  and the distal section  1426  to bring the ends of the distal section near the respective faces  1427 ,  1428  of the lites  1401 ,  1402 . The distal sections  1426  are further folded to bring at least a first part  1429  of each distal section parallel to the faces  1427 ,  1428  of the lites. As further described herein, each first part  1429  of the distal section  1426  is then bonded to the respective adjacent face  1427 ,  1428  of the lites  1401 ,  1402  to form a hermetic bond  1430  ( FIG. 14 d   ). The hermetic bond  1430  must be capable of blocking the passage of gasses into the cavity  1403  to maintain the required hermeticity, but it is not required to withstand any significant structural loads arising from the compliant portion  1420  of the edge seal  1405 . In some embodiments, the hermetic bond  1430  comprises a solder. In preferred embodiments, the solder is a metallic solder, however, in other embodiments the solder may be a solder glass. 
     Referring now to  FIG. 14 c   , after hermetically bonding the first part  1429  of each distal section  1426  to the faces  1427 ,  1428  of the lites  1401 ,  1402 , the lateral portion  1422  is folded again such that the remaining parts of the distal section lie substantially parallel to the faces. As further described herein, a portion of each remaining part of the distal section  1426 , but not including any portion directly overlying the hermetic bond  1430 , is then bonded to the respective adjacent face  1427 ,  1428  to form a structural bond  1432  ( FIG. 14 d   ). The structural bond  1432 , unlike the hermetic bond  1430 , need not be capable of blocking the passage of gasses into the cavity  1403 . Instead, the structural bond  1432  must withstand the structural loads arising from the compliant portion  1420  and prevent the transmission of any significant structural loads to the hermetic bond  1430 . Accordingly, the structural bond  1432  is always interposed along the edge seal  1405  between the compliant portion  1420  and the hermetic bond  1430  (i.e., when considering the edge seal  1405  as extending continuously from one distal end to the opposite distal end). The structural bond  1432  may be formed of the same materials previously described in connection with structural bond  1332  of the previous embodiment. 
     Referring now to  FIG. 14 d   , the VIGU  1400  is shown, including the lites  1401 ,  1402 , edge seal  1405  and stand-off members  1425  (again, for purposes of illustration, only an end portion of the complete VIGU is shown). In one embodiment of the VIGU  1400 , the hermetic materials, including the hermetic bond  1430 , are hermetic for at least ten years. In another embodiment, the hermetic materials, including the hermetic bond  1430 , are hermetic for at least thirty years. In yet another embodiment, the hermetic materials, including the hermetic bond  1430 , are hermetic for at least forty years. In a preferred embodiment, the insulating cavity  1403  is evacuated to a vacuum within the range of 1×10 −6  torr to 1×10 −3  torr. Alternatively, an insulating glazing unit (IGU) (not shown) may be constructed in a substantially identical fashion, except the materials and seals need not be hermetic and the atmosphere within the insulating cavity is a partial vacuum and/or filed with an insulating gas or gas mixture. As describe above, the evacuation, partial evacuation or (in the case of IGUs) filling with insulating gasses of the insulating cavity  1403  may be achieved at the time of sealing the insulating cavity by sealing it while the VIGU/IGU  1400  is in, respectively, a vacuum chamber, a partial vacuum chamber or a gas-filled chamber. Alternatively, the evacuation and/or filling of the insulating cavity  1403  may be achieved after the insulating cavity has been sealed via an evacuation tube. 
     Referring now to  FIGS. 15, 16, 17 and 18  there are illustrated perspective views of various VIGU/IGUs  1500 ,  1600 ,  1700  and  1800  showing the seal configuration of the respective edge seals  1502 ,  1602 ,  1702  and  1802  as they are attached to the corners of the respective glass lites  1501 ,  1601 ,  1701  and  1801 . 
     A preferred method for forming the hermetic bonds, e.g., the hermetic bonds  1330  or  1430  previously described, is by ultrasonic soldering using a flux-free solder. Suitable flux-free solder and ultrasonic soldering equipment are produced by Cerasolzer, for example Cerasolzer GS 217 solder or GS 220 solder. In a preferred embodiment, the surfaces of the edge seal and the lites that are to be bonded in the hermetic bond have solder pre-applied (i.e., known as “pre-tinning”). Further, at least the surfaces to be hermetically bonded, and preferably the entire lites, are preheated to a pre-heat temperature above the solder&#39;s liquidus temperature prior to forming the hermetic bonds. 
     In one embodiment, the following steps are used: (1) Pre-heat the glass lite and pre-tin the perimeter of the glass lite using ultrasonic soldering; (2) Pre-tin the inside of the metal edge band that will later be wrapped around and soldered to the glass lite; (3) The metal edge band does not have to be pre-heated but it is preferable to do so before ultrasonically solder pre-tinning its surface; (4) Use tooling ( FIG. 19 d   ) to stretch the pre-tinned metal band so it is large enough to slide onto the perimeter of the now pre-tinned glass; (5) Pre-heat the assembly past the liquid temperature of the solder; and (6) Apply heat and ultrasonic excitation to the metal band to again break any oxides in the molten solder, moving the hot soldering iron tip all the way around the metal band. If the metal band is elastic enough after stretching, apply the ultrasonic energy to the band where it overlaps the perimeter edge of the glass. Preferably, a compressive fixture is used to hold the edge seal band tight against the perimeter of the pre-tinned glass lite. 
     Ultrasonic excitation is applied to the part of the metal band that extends past the edge of the glass and have the band-tensioning fixture apply the pressure to keep the metal band in very close contact with the glass edge. The band and glass cannot be in intimate contact as we have solder between the two and want to achieve a hermetic soldered bond or connection. 
     Referring now to  FIGS. 19 a , 19 b , 19 c , 19 d  and 19 e   , an automated process for applying metal bands around the lite or lites is described that may comprise the following steps. The glass is cut and the edge is prepared for solder pre-tinning, if necessary by one of several means. Cleaning may be required prior to soldering. Smoothing the edge may be required to result in less porosity and a more hermetic solder-to-glass interface. This is an especially important consideration if the glass is cut using a water jet cutter, as the abrasive cutting fluid leaves grooves horizontal to the two large surfaces of the glass, 90 degrees or perpendicular from the direction one would want if one had to work with soldering to a grooved perimeter surface. Glass fabricators call the process of smoothing the edge of cut glass, “seaming.” Smoothing processes are done prior to tempering the glass. These include grinding, sanding, heating such as with a torch to locally melt the glass to form a smooth surface, polishing, and other processes. After any smoothing and cleaning operations, preheat the glass and pre-tin the glass lite&#39;s perimeter. Cut the metal strip  1900  for the edge seal (or edge seal bands) to the correct length ( FIG. 19 a   ), dress the ends  1902  ( FIG. 19 b   ) and butt-weld the band together ( FIG. 19 c   ) by TIG, laser or other means and then pre-tin the inside of the band where it will come into contact with the edge of the glass lite  1903 . Stretch the completed band  1904  ( FIG. 19 d   ) using a stretching fixture  1906  enough to enable the edge seal/band system  1904  to then slide the stretched band over or around the perimeter of the glass lite  1903  ( FIG. 19 e   ). Next, the banded assembly  1910  is heated until the flux-free solder is in a liquid state. Ultrasonic excitation may be applied. Compressive force may be applied to increase the molten solder&#39;s contact area between the metal band and the glass lite. After the metal band  1904  is completely soldered to the glass lite  1903 , the assembly is cooled to room temperature, probably with blowing air to decrease the cool-down time. Another way to apply pressure while soldering would be to have one or more heated rollers apply simultaneous pressure and ultrasonic energy to the outside of the pre-tinned metal band of the heated assembly and have the rollers travel around the heated assembly until all the molten solder has been agitated with appropriate ultrasonic energy. 
     It will be appreciated by those skilled in the art having the benefit of this disclosure that this method and apparatus for an insulating glazing unit and compliant seal for an insulating glazing unit provides an insulating glazing unit having greatly improved performance and lifespan. It should be understood that the drawings and detailed description herein are to be regarded in an illustrative rather than a restrictive manner, and are not intended to be limiting to the particular forms and examples disclosed. On the contrary, included are any further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments apparent to those of ordinary skill in the art, without departing from the spirit and scope hereof, as defined by the following claims. Thus, it is intended that the following claims be interpreted to embrace all such further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments.