Patent Publication Number: US-2018038152-A1

Title: Manufacturing method for glass panel unit and manufacturing method for glass window

Description:
TECHNICAL FIELD 
     The present invention relates to manufacturing methods for glass panel unit and manufacturing methods for glass window, and in more detail to a manufacturing methods for a glass panel unit including a first glass substrate and a second glass substrate bonded to each other with a seal member, and a manufacturing methods for a glass window including the glass panel unit. 
     BACKGROUND ART 
     Patent Literature 1 discloses a glass panel unit where a pair of glass substrates placed facing each other are bonded to each other with a seal member. 
     Each of the pair of glass substrates is a glass substrate formed to have predetermined shape and dimensions, and outer peripheries of the pair of glass substrates are bonded to each other with the seal member. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: JP H11-79799 A 
     SUMMARY OF INVENTION 
     As to a conventional manufacturing method for a glass panel unit as shown in Patent Literature 1, the pair of glass substrates are cut to have determined shape and dimensions in advance. Subsequently, in a sealing furnace, the pair of glass substrate between which the seal member is sandwiched are heated, and thereby bonded to each other with the seal member to form a glass panel unit with desired shape and dimensions. 
     Accordingly, the conventional manufacturing method described above requires shaping glass substrates to have shape and dimensions corresponding to a type (shape and dimensions) of a glass panel unit to be manufactured, and bonding the shaped glass substrates to each other in a furnace. This may lead to a decrease in efficiency. 
     An object to be solved by the present invention would be to efficiently manufacture a glass panel unit with desired shape and dimensions and a glass window including the same. 
     To solve the above object, a manufacturing method for glass panel unit according to one aspect of the present invention includes a placing step, a bonding step, and a cutting step. 
     The placing step is a step of placing a first glass substrate and a second glass substrate to face each other with a seal member in-between. 
     The bonding step is a step of bonding the first glass substrate and the second glass substrate to each other with the seal member. 
     The cutting step is a step of cutting the first glass substrate, the seal member, and the second glass substrate collectively along a cut plane imaginary passing through the seal member from one of the first glass substrate and the second glass substrate bonded to each other. 
     A manufacturing method for glass window according to one aspect of the present invention includes an assembling step of fitting the glass panel unit manufactured by the manufacturing method for glass panel unit according to the aspect according to the present invention, into a window frame. The treatment step includes evacuating air from the inside space. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view for illustration of a placing step in a manufacturing method for a glass panel unit of the first embodiment. 
         FIG. 2  is a plan for illustration of a bonding step in the manufacturing method for the glass panel unit of the first embodiment. 
         FIG. 3  is a section taken along line A-A in  FIG. 2 . 
         FIG. 4  is a partial cutaway for illustration of a treatment step and a cutting step in the manufacturing method for the glass panel unit of the first embodiment. 
         FIG. 5  is a primary section for illustration of the cutting step in the manufacturing method for the glass panel unit of the first embodiment. 
         FIG. 6  is a plan of a glass panel unit manufactured by the manufacturing method for the glass panel unit of the first embodiment. 
         FIG. 7  is a section taken along line B-B in  FIG. 6 . 
         FIG. 8  is a flow chart for illustration of the manufacturing method for the glass panel unit of the first embodiment. 
         FIG. 9  is a plan for illustration of a placing step and a bonding step in a manufacturing method for a glass panel unit of the second embodiment. 
         FIG. 10  is a section taken along line C-C in  FIG. 9 . 
         FIG. 11  is a plan view for illustration of a treatment step and a cutting step in the manufacturing method for the glass panel unit of the second embodiment. 
         FIG. 12  is a plan for illustration of a placing step and a bonding step in a manufacturing method for a glass panel unit of the third embodiment. 
         FIG. 13  is a section taken along line D-D in  FIG. 12 . 
         FIG. 14  is a partially cutaway plan for illustration of a treatment step and a treatment step and a cutting step in the manufacturing method for the glass panel unit of the third embodiment. 
         FIG. 15  is a primary section for illustration of a cutting step in a manufacturing method for a glass panel unit of the fourth embodiment. 
         FIG. 16  is a primary section for illustration of the cutting step in the manufacturing method for the glass panel unit of the fourth embodiment. 
         FIG. 17  is a primary section for illustration of the cutting step in the manufacturing method for the glass panel unit of the fourth embodiment. 
         FIG. 18  is a flow chart for illustration of the manufacturing method for the glass panel unit of the fourth embodiment. 
         FIG. 19  is a plan of a glass panel unit manufactured by a manufacturing method for a glass panel unit of the fifth embodiment. 
         FIG. 20  is a section taken along line E-E in  FIG. 19 . 
         FIG. 21  is a flow chart for illustration of the manufacturing method for the glass panel unit of the fifth embodiment. 
         FIG. 22  is a plan of a glass window including the glass panel unit of the first embodiment. 
         FIG. 23  is a flow chart for illustration of a manufacturing method for the glass window including the glass panel unit of the first embodiment. 
         FIG. 24  is a plan of a glass window including the glass panel unit of the fifth embodiment. 
         FIG. 25  is a flow chart for illustration of a manufacturing method for the glass window including the glass panel unit of the fifth embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     (Glass Panel Unit of First Embodiment) 
     A manufacturing method for glass panel unit of the first embodiment includes a placing step S 1 , a bonding step S 2 , a treatment step S 3 , and a cutting step S 4  (see  FIG. 8 ). 
     The placing step S 1  is a step of placing a first glass substrate  1  and a second glass substrate  2  to face each other with a seal member  3  in-between (see  FIG. 1  to  FIG. 3 ). 
     The bonding step S 2  is a step of bonding the first glass substrate  1  and the second glass substrate  2  which are placed by the placing step S 1 , to each other with the seal member  3 . Thereby, an inside space  4  is formed between the first glass substrate  1  and the second glass substrate  2 , and the inside space  4  is partitioned by part (a partition member  32 ) of the seal member  3  into a first space  41  and a second space  42  (see  FIG. 2  and  FIG. 3 ). The first space  41  and the second space  42  are interconnected by gas passages  43 . 
     The treatment step S 3  is a step of hermetically enclosing the first space  41  by evacuating air from the inside space  4  (the first space  41  and the second space  42 ) via a vent  7  provided to the second glass substrate  2  and then deforming the part (the partition member  32 ) of the seal member  3  (see  FIG. 4 ). 
     The cutting step S 4  is a step of physically separating the first space  41  and the second space  42  from each other by cutting the first glass substrate  1 , the seal member  3 , and the second glass substrate  2  along a cut plane  900  imaginary passing through the part (the deformed partition member  32 ) of the seal member  3  from the first glass substrate  1  (see  FIG. 4  to  FIG. 7 ). 
     Hereinafter, each step is described in more detail. 
     &lt;Placing Step&gt; 
     In the placing step S 1 , the first glass substrate  1 , the second glass substrate  2 , the seal member  3 , multiple spacers  5 , and a gas adsorbent  55  shown in  FIG. 1  to  FIG. 3  are placed on designated positions, respectively. 
     The first glass substrate  1  is a rectangular flat plate and includes a first face  11  on one side in a thickness direction thereof and a second face  12  on the other side in the thickness direction. The first face  11  and the second face  12  of the first glass substrate  1  are flat planes parallel to each other. 
     Examples of material of the first glass substrate  1  may include soda lime glass, high strain point glass, chemically strengthened glass, non-alkaline glass, quartz glass, neoceram, and physically strengthened glass. 
     The first face  11  of the first glass substrate  1  is constituted by an outer face of a coating  13  (see  FIG. 3 ). One example of the coating  13  is an infrared reflective film but the coating  13  may be a film with desired physical properties. The first glass substrate  1  may not include the coating  13 . 
     The second glass substrate  2  is a rectangular flat plate likewise the first glass substrate  1 . The second glass substrate  2  includes a first face  21  on one side in a thickness direction thereof and a second face  22  on the other side in the thickness direction. The first face  21  and the second face  22  of the second glass substrate  2  are flat planes parallel to each other. The vent  7  is formed in a corner of the second glass substrate  2 . 
     Examples of material of the second glass substrate  2  may include soda lime glass, high strain point glass, chemically strengthened glass, non-alkaline glass, quartz glass, neoceram, and physically strengthened glass. 
     The first glass substrate  1  and the second glass substrate  2  are placed opposite each other. Here, the first face  11  of the first glass substrate  1  and the first face  21  of the second glass substrate  2  are positioned parallel to and opposite each other (see  FIG. 3 ). 
     The seal member  3  is placed between the first glass substrate  1  and the second glass substrate  2 . The seal member  3  includes a frame member  31  with a rectangular frame shape and the partition member  32 . The frame member  31  and the partition member  32  are placed on the first face  21  of the second glass substrate  2 . 
     The frame member  31  is placed on the first face  21  so as to extend along an outer periphery of the second glass substrate  2 , and the partition member  32  is placed on the first face  21  so as to be enclosed by the frame member  31 . 
     The first glass substrate  1  and the second glass substrate  2  are hermetically bonded to each other with the seal member  3  (the frame member  31  and the partition member  32 ). Thereby, the inside space  4  is formed between the first glass substrate  1  and the second glass substrate  2 . The inside space  4  is a space enclosed by the frame member  31 , the first glass substrate  1 , and the second glass substrate  2 . 
     The frame member  31  and the partition member  32  both are formed of grass frit (glass paste). Examples of the glass frit may include low-melting point glass frit such as bismuth-based glass frit, lead-based glass frit, and vanadium-based glass frit. 
     The partition member  32  includes a wall part  321  with a straight shape and a pair of closing parts  322  extending from opposite ends in a lengthwise direction of the wall part  321 . The pair of closing parts  322  each extends in a direction perpendicular to the lengthwise direction of the wall part  321 . 
     The gas passages  43  are formed between the partition member  32  and the frame member  31 . 
     The gas passages  43  are a space formed between one end in the lengthwise direction of the wall part  321  and the frame member  31  and a space formed between the other end in the lengthwise direction of the wall part  321  and the frame member  31 . Note that, locations and the number of gas passages  43  may not be limited to the current case. 
     The multiple spacers  5  are placed on the first face  21  of the second glass substrate  2 . The multiple spacers  5  are used to keep a predetermined interval between the first glass substrate  1  and the second glass substrate  2 . 
     The multiple spacers  5  each are made of transparent material to have a solid cylindrical shape. Materials of individual spacers  5 , sizes of individual spacers  5 , shapes of individual spacers  5 , intervals between adjacent spacers  5 , and patterns of arrangement of multiple spacers  5  may be appropriately selected. Note that, only one spacer  5  may be placed or no spacer  5  may be placed. 
     The gas adsorbent  55  is placed on the first face  21  of the second glass substrate  2 . On the first face  21 , the gas adsorbent  55  is positioned separate from the partition member  32  and the gas passages  43 . The gas adsorbent  55  is used for adsorbing gas emitted from the frame member  31  and the partition member  32  when heated. Note that, the gas adsorbent  55  may be contained in one or more spacers  5 , or no gas adsorbent  55  may be placed. 
     &lt;Bonding Step&gt; 
     In the bonding step S 2 , the first glass substrate  1  and the second glass substrate  2  which are set with the seal member  3  and the like in-between are heated in a sealing furnace, as shown in  FIG. 2  and  FIG. 3 . 
     In the bonding step S 2 , a temperature inside the sealing furnace is set to a predetermined temperature (hereinafter referred to as a “first melting temperature”) equal to or higher than a softening point of the frame member  31 . The frame member  31  is molten one time inside the furnace with the first melting temperature, and thereby the first glass substrate  1  and the second glass substrate  2  are hermetically bonded to each other by way of the frame member  31 . 
     In more detail, the first glass substrate  1  and the second glass substrate  2  placed inside the sealing furnace are heated at the first melting temperature for a predetermined period of time. In this regard, the first melting temperature and the predetermined period of time are determined so that the partition member  32  does not close the gas passages  43 / 
     Formed between the first glass substrate  1  and the second glass substrate  2  bonded to each other is the inside space  4  enclosed by the frame member  31 . The inside space  4  is partitioned by the partition member  32  into the first space  41  and the second space  42 . At the time of completion of the bonding step S 2 , gas is allowed to move between the first space  41  and the second space  42  through the gas passages  43  positioned between the frame member  31  and the partition member  32 . 
     The first space  41  is a space where the multiple spacers  5  and the gas adsorbent  55  are located. The second space  42  is a space directly connected to the vent  7 . 
     The vent  7  interconnects the second space  42  and an outside space. The vent  7  of the present embodiment is used for evacuating air from the first space  41  through the second space  42  and the gas passages  43 . 
     &lt;Treatment Step&gt; 
     The treatment step S 3  is a step of making the inside space  4  to be an evacuated space, and includes an evacuating step and a hermetically enclosing step. The evacuating step and the hermetically enclosing step of the treatment step S 3  are performed inside the sealing furnace subsequent to the bonding step S 2 . 
     The evacuating step is a step of making a whole of the inside space  4  to be in a vacuum state by evacuating air from the inside space  4  to outside via the vent  7 . 
     In the evacuating step of the present embodiment, air inside the first space  41  is evacuated to outside through the gas passages  43 , the second space  42 , and the vent  7 , and thus pressure of the first space  41  is reduced until the first space  41  is made to be the evacuated space. This evacuating process is performed by use of a vacuum pump with an evacuation pipe  71  (see  FIG. 1 ) coupled with the second glass substrate  2  to be connected to the vent  7 , for example. An evacuation period of time is determined so that the evacuated space has a desired degree of vacuum (for example, a degree of vacuum of 0.1 Pa or less). 
     In the hermetically enclosing step, the partition member  32  is molten at a predetermined temperature (hereinafter referred to as a “second melting temperature”) equal to or higher than the softening point of the partition member  32 , and thereby the partition member  32  is deformed to close the gas passages  43 . Thus, a whole periphery of the first space  41  made to be in a vacuum state is enclosed by the frame member  31  and the partition member  32 , and accordingly the first space  41  is hermetically enclosed so as not to allow movement of gas between the first space  41  and the outside see  FIG. 4 ). 
     In more detail, the partition member  32  is deformed so that the closing part  322  at one end of the partition member  32  closes one of the gas passages  43  and the closing part  322  at the other end closes the other of the gas passages  43  (see  FIG. 2  and  FIG. 4 ). The partition member  32  deformed serves as a separator for hermetically dividing the inside space  4  in the vacuum state into the first space  41  and the second space  42 . 
     The second melting temperature for melting the partition member  32  is set to a temperature higher than the first melting temperature. In other words, the partition member  32  is prepared to be deformed at a temperature higher than the first melting temperature to close the gas passages  43 . Such temperature settings are expected to prevent deformation of the partition member  32  to close the gas passages  43  in bonding the first glass substrate  1  and the second glass substrate  2  to each other in the bonding step S 2 . 
     Through the aforementioned treatment step S 3 , it is possible to produce a temporary-assembled unit  8  including the first space  41  made to be the evacuated space, as shown in  FIG. 4 . 
     &lt;Cutting Step&gt; 
     In the cutting step S 4 , the temporary-assembled unit  8  taken out from the sealing furnace is cut along the cut plane  900  imaginary shown in  FIG. 4  and  FIG. 5 , and thereby physically divided into a part  81  including the first space  41  and a part  82  including the second space  42 . The cut plane  900  is set to pass through an entire length of the partition member  32  in a plan view (a front view of the second face  12  of the first glass substrate  1 ). 
     To cut the temporary-assembled unit  8  along the cut plane  900 , a cutting device  9  as shown in  FIG. 5  is used. The cutting device  9  is a scribing device provided at its end with a wheel  91  for cutting. 
     The wheel  91  of the cutting device  9  is moved along the cut plane  900  wit being pressed against one surface of the temporary-assembled unit  8  (that is, the second face  12  of the first glass substrate  1 . Thereby the first glass substrate  1 , the seal member  3 , and the second glass substrate  2  are collectively cut along the cut plane  900 . 
     Since the partition member  32  is of glass frit molten once, the temporary-assembled unit  8  includes the first glass substrate  1  and the second glass substrate  2  which are integrated strongly by the partition member  32 . Therefore, when the wheel  91  is moved with being pressed against one side, a deep crack will develop in thickness directions of the first glass substrate  1  and the second glass substrate  2 . As a result, the first glass substrate  1 , the partition member  32 , and the second glass substrate  2  are cut along the cut plane  900  smoothly as with a single plate of glass. In summary, without splitting after scribing, the temporary-assembled unit  8  is cut smoothly as if it is a single glass panel. 
     One part  81  cut from the temporary-assembled unit  8  is used as a glass panel unit (thermally insulated glass panel unit), and the other part  82  cut therefrom is an unnecessary part. The part  81  used as a glass panel unit has a sectional plane  811  including sectional planes of the first glass substrate  1 , the seal member  3  (the partition member  32 ), and the second glass substrate  2  which are consecutive and flush to each other (see  FIG. 6  and  FIG. 7 ). Therefore, physical strength can be ensured and handleability can be improved without the sectional plane  811  being further processed. Note that, of course, the sectional plane  811  may be further processed. 
     The cutting device  9  may preferably include a mechanism for giving vibration to the wheel  91 . A direction of the vibration would be the thickness directions of the first glass substrate  1  and the second glass substrate  2 , that is a direction where the first glass substrate  1 , the partition member  32 , and the second glass substrate  2  are stacked. Giving that vibration in cutting can facilitate collectively cutting the first glass substrate  1 , the partition member  32 , and the second glass substrate  2 . 
     Note that, the cutting device  9  may be pressed against the second glass substrate  2  to cut the temporary-assembled unit  8  along the cut plane  900 . Examples of alternative devices to the cutting device  9  may include a cutting device with water jet and a cutting device with laser irradiation. 
     (Glass Panel Unit of Second Embodiment) 
     A manufacturing method for a glass panel unit of the second embodiment is described with reference to  FIG. 9 ,  FIG. 10 , and  FIG. 11 . Note that, same components as the first embodiment are designated by common reference signs to avoid detailed descriptions, and different components from the first embodiment are described in detail. 
     In the manufacturing method for glass panel unit of the present embodiment, a single temporary-assembled unit  8  is formed to obtain two glass panel units from the single temporary-assembled unit  8 . 
     In the manufacturing method for glass panel unit of the present embodiment, a step of obtaining two glass panel units includes a placing step S 1 , a bonding step S 2 , a treatment step S 3  (an evacuating step and a hermetically enclosing step), and a cutting step S 4 . 
     In the placing step S 1 , a first glass substrate  1  and a second glass substrate  2  are placed opposite each other with a seal member  3  (a frame member  31  and a partition member  32 ) in-between. In the bonding step S 2 , the first glass substrate  1  and the second glass substrate  2  are bonded to each other with the seal member  3 . 
     An inside space  4  enclosed by the frame member  31  between a first glass substrate  1  and a second glass substrate  2  is partitioned by the partition member  32  into two first spaces  41  and one second space  42  (see  FIG. 9 ). Hereinafter, a first one of the first spaces  41  is designated by reference sign  41   a  and a second one of the first spaces  41  is designated by reference sign  41   b.    
     The partition member  32  of the present embodiment includes a wall part  321   a  for separating the first space  41   a  and the second space  42  from each other, a wall part  321   b  for separating the first space  41   b  and the second space  42  from each other, and a wall part  321   c  for separating the first space  41   a  and the first space  41   b  from each other. 
     The partition member  32  of the present embodiment includes two gas passages  43 . Hereinafter, a first one of the gas passages  43  is designated by reference sign  43   a  and the second one of the gas passages  43  is designated by reference sign  43   b.    
     The gas passage  43   a  is formed in the wall part  321   a  and thereby the first space  41   a  and the second space  42  are interconnected by the gas passage  43   a  to allow gas to move therebetween. The gas passage  43   b  is formed in the wall part  321   b  and thereby the first space  41   b  and the second space  42  are interconnected by the gas passage  43   b  to allow gas to move therebetween. Note that, locations and the number of gas passages  43   a  and gas passages  43   b  are not limited to this example. 
     In the evacuating step of the treatment step S 3 , air is evacuated from the inside space  4  through a vent  7  directly connected to the second space  42  and thereby a whole of the inside space  4  is made to be an evacuated space. 
     Subsequently, in the hermetically enclosing step of the treatment step S 3 , the wall part  321   a  and the wall part  321   b  of the partition member  32  are deformed by heating to thereby close the gas passage  43   a  and the gas passage  43   b  to prevent gas from moving therethrough. Through the aforementioned treatment step S 3 , it is possible to produce a temporary-assembled unit  8  including the first space  41   a  and the first space  41   b  each made to be the evacuated space, as shown in  FIG. 11 . 
     In the cutting step S 4 , the temporary-assembled unit  8  is cut along a cut plane  900  imaginary shown in  FIG. 11 . By cutting, the temporary-assembled unit  8  is physically divided into a part  81   a  including the first space  41   a  hermetically enclosed, a part  81   b  including the first space  41   b  hermetically enclosed, and a part  82  including the second space  42 . Also in the present embodiment, the cutting device  9  shown in  FIG. 5  may be preferably used. 
     The part  81   a  including the first space  41   a  in a vacuum state and the part  81   b  including the first space  41   b  in a vacuum state which are cut from the temporary-assembled unit  8  are each used as a glass panel unit (thermally insulated glass panel unit). The part  82  including the second space  42  and the vent  7  is an unnecessary part. 
     Also in the present embodiment, the temporary-assembled unit  8  has a structure where the first glass substrate  1 , the seal member  3 , and the second glass substrate  2  are stacked. However, since the temporary-assembled unit  8  is cut along the cut plane  900  passing through the seal member  3  (the partition member  32 ), the first glass substrate  1 , the seal member  3 , and the second glass substrate  2  can be cut collectively as if a single glass plate is cut. 
     Note that, in the present embodiment, the temporary-assembled unit  8  is formed to give two glass panel units. However, the temporary-assembled unit  8  may be formed to give three or more glass panel units (that is, to allow taking out three or more parts from a whole). 
     (Glass Panel Unit of Third Embodiment) 
     A manufacturing method for a glass panel unit of the third embodiment is described with reference to  FIG. 12  to  FIG. 14 . Note that, same components as the first embodiment are designated by common reference signs to avoid detailed descriptions, and different components from the first embodiment are described in detail. 
     In the manufacturing method for glass panel unit of the present embodiment, a glass panel unit can be obtained by way of a placing step S 1 , a bonding step S 2 , a treatment step S 3 , and a cutting step S 4 . 
     In the present embodiment, in the treatment step S 3 , a pressure of an inside space  4  is not reduced until the inside space  4  is in a vacuum state but a whole of the inside space  4  is filled with gas  400  through a vent  7  and gas passages  43  (see  FIG. 12 ). After that, part (a partition member  32 ) of a seal member  3  is deformed by heating to hermetically enclose a first space  41 . Examples of the gas  400  may include low thermal conductive gas such as dry air and argon gas. 
     Through the aforementioned treatment step S 3 , it is possible to produce a temporary-assembled unit  8  including the first space  41  filled with gas  400 , as shown in  FIG. 14 . 
     In the cutting step S 4 , the temporary-assembled unit  8  is cut along a cut plane  900  and thereby physically divided into a part  81  including the first space  41  and a part  82  including a second space  42 . The cut plane  900  is provided straightly to pass through an entire length of the partition member  32 . 
     One part  81  cut from the temporary-assembled unit  8  is used as a glass panel unit (thermally insulated glass panel unit) where a space between the first glass substrate  1  and the second glass substrate  2  is filled with the gas  400 , and the other part  82  including the second space  42  is an unnecessary part. 
     (Glass Panel Unit of Fourth Embodiment) 
     A manufacturing method for a glass panel unit of the fourth embodiment is described with reference to  FIG. 15  to  FIG. 18 . Note that, same components as the first embodiment are designated by common reference signs to avoid detailed descriptions, and different components from the first embodiment are described in detail. 
     In the manufacturing method for glass panel unit of the present embodiment, a glass substrate with wire  25  embedded therein is used as a second glass substrate  2 . The wire  25  may be formed into mesh, for example. 
     As shown in  FIG. 18 , the manufacturing method for glass panel unit of the present embodiment includes a placing step S 1 , a bonding step S 2 , a treatment step S 3 , and a cutting step S 4 , and additionally a the wire cutting step S 5 . 
     The placing step S 1 , the bonding step S 2 , and the treatment step S 3  of the present embodiment are same as or similar to those in the first embodiment. Hereinafter, the cutting step S 4  and the wire cutting step S 5  are described in detail. 
     In the cutting step S 4 , a first glass substrate  1  is placed above the second glass substrate  2 , and a temporary-assembled unit  8  is held in a posture where a second face  12  of the first glass substrate  1  points upward. And, a wheel  91  of a cutting device  9  is moved along a cut plane  900  with it being pressed against the second face  12  of the first glass substrate  1  from the above. With movement of the wheel  91 , a crack  61  along the cut plane  900  propagates (develops) from the second face  12  (upper face) of the first glass substrate  1  toward the second glass substrate  2  (see  FIG. 15 ). 
     Here, when external force is applied to the temporary-assembled unit  8  in directions (directions of arrows shown in  FIG. 16 ) so as to bend the temporary-assembled unit  8  with the second glass substrate  2  pointing inward, the crack  61  further develops along the cut plane  900 , and thereby the first glass substrate  1 , the seal member  3 , and the second glass substrate  2  are collectively cut by the crack  61  developed. At the time of completion of the cutting step S 4 , the wire  25  is not cut yet but remains. 
     The wire cutting step S 5  is a step of cutting the wire  25  of the second glass substrate  2  after the first glass substrate  1 , the seal member  3 , and the second glass substrate  2  are cut collectively in the cutting step S 4 . 
     Through the wire cutting step S 5 , the wire  25  is cut into wire  251  embedded in one part  81  (a part used as a glass panel unit) from the temporary-assembled unit  8  and wire  252  embedded in the other part  82  (an unnecessary part). The wire  251  may be preferably subjected to appropriate treatment not to protrude outside from the sectional plane  811 . 
     As described above, the crack  61  is made to propagate from the first glass substrate  1  to thereby break the temporary-assembled unit  8  with the second glass substrate  2  with wire  25  pointing inward. Hence, it is possible to suppress breakage from occurring accompanied by cutting. In more detail, in breaking the temporary-assembled unit  8 , in an inward region of the bent wire  25  (a region  62  shown in  FIG. 16 ) pieces of glass may easily strike each other. However, the region  62  is a short distance from the wire  25  and therefore pieces of glass can be suppressed from striking each other with great force, leading to a decrease in breakage. 
     The manufacturing method for the glass panel unit of the second or third embodiment also may include steps similar to the steps of the fourth embodiment. 
     In more detail, also in the second or third embodiment, the glass substrate with the wire  25  embedded therein may be used as the second glass substrate  2 . And, the crack  61  may be made to develop from the first glass substrate  1  and the first glass substrate  1 , the seal member  3 , and the second glass substrate  2  may be cut collectively by bending them with the second glass substrate  2  pointing inward. After that, the wire  25  of the second glass substrate  2  may be cut. 
     (Glass Panel Unit of Fifth Embodiment) 
     A manufacturing method for a glass panel unit of the fifth embodiment is described with reference to  FIG. 19  to  FIG. 21 . Note that, same components as the first embodiment are designated by common reference signs to avoid detailed descriptions, and different components from the first embodiment are described in detail. 
     As shown in  FIG. 21 , the manufacturing method for glass panel unit of the present embodiment includes a placing step S 1 , a bonding step S 2 , a treatment step S 3 , and a cutting step S 4 , and in addition a second bonding step S 6 . 
     The second bonding step S 6  is a step of bonding a first glass substrate  1  and a third glass substrate  63  to each other with a second seal member  64  with a frame shape to form a second inside space  65  enclosed by the second seal member  64 . 
     Examples of material of the third glass substrate  63  may include soda lime glass, high strain point glass, chemically strengthened glass, non-alkaline glass, quartz glass, neoceram, and physically strengthened glass. 
     There is a spacer  66  inside the second seal member  64 , and the spacer  66  has a frame shape with a hollow inside space. The hollow inside space of the spacer  66  is filled with desiccant  67 . 
     The spacer  66  is made of metal such as aluminum and includes through holes  661  at its inner peripheral side. The hollow inside space of the spacer  66  is connected to the second inside space  65  through the through holes  661 . Examples of the desiccant  67  may include silica gel. Examples of material for the second seal member  64  may include highly airtight resin such as silicone resin and butyl rubber. 
     The second inside space  65  is a space hermetically separated from outside. The second inside space  65  is filled with the dry gas  600 . Examples of the dry gas  600  may include dry rare gas such as dry argon as well as dry air. Examples of the dry air may include air which is introduced in the second inside space  65  and then dried due to action of the desiccant  67 . 
     According to the glass panel unit manufactured by the present embodiment, the first space  41  of which pressure is reduced until vacuum and the second inside space  65  filled with the dry gas  600  are interposed between the third glass substrate  63  and the second glass substrate  2  on opposite sides in the thickness direction. Thereby, thermally insulating properties can be more improved. 
     In the present embodiment, the third glass substrate  63  is placed opposite the first glass substrate  1 . However, the third glass substrate  63  may be placed opposite the second glass substrate  2 . In this case, in the second bonding step S 6 , peripheries of the second glass substrate  2  and the third glass substrate  63  are bonded together by the second seal member  64  with the spacer  66  being interposed between the second glass substrate  2  and the third glass substrate  63 . By doing so, the second inside space  65  is formed between the second glass substrate  2  and the third glass substrate  63 . 
     Note that, the manufacturing method for the glass panel unit of the second, third, or fourth embodiment also may include steps similar to the steps of the fifth embodiment. 
     In more detail, the second, third, or fourth embodiment may further include the second bonding step S 6  of bonding one of the first glass substrate  1  and the second glass substrate  2  cut in the cutting step S 4  to the third glass substrate  63  with the second seal member  64  with the frame shape. Also in this case, the second inside space  65  enclosed by the second seal member  64  with the frame shape is formed, leading to a further increase in thermal insulating properties. 
     (Glass Windows with First to Fourth Glass Panel Units) 
     First, a manufacturing method for a glass window including the glass panel unit of the first embodiment is described with reference to  FIG. 22  and  FIG. 23 . 
     As shown in  FIG. 22 , the glass panel unit of the first embodiment and a window frame  68  constitute a glass window. 
     The manufacturing method for glass window includes, as shown in  FIG. 23 , the placing step S 1 , the bonding step S 2 , the treatment step S 3 , and the cutting step S 4  included in the manufacturing method for the glass panel unit of the first embodiment, and additionally an assembling step S 7  of fitting a glass panel unit manufactured through the individual steps S 1 , S 2 , S 3 , and S 4  into the window frame  68  with a rectangular shape. In the treatment step S 3 , air is evacuated from the inside space  4 . 
     Since the glass window manufactured by this method has a structure where the glass panel unit including the first space  41  between the first glass substrate  1  and the second glass substrate  2  is fitted into the window frame  68  and the first space  41  has reduced pressure, the glass window has improved thermally insulating properties. 
     Similarly, the glass panel unit of any of the second to fourth embodiments may be fitted into the window frame  68  in the assembling step S 7  in a similar way. Also in this case, the glass window manufactured through the assembling step S 7  includes the first space  41  with reduced pressure between the first glass substrate  1  and the second glass substrate  2 , and therefore has improved thermally insulating properties. 
     (Glass Window with Fifth Glass Panel Units) 
     A manufacturing method for a glass window including the glass panel unit of the fifth embodiment is described with reference to  FIG. 24  and  FIG. 25 . 
     As shown in  FIG. 24 , the glass panel unit of the fifth embodiment and a window frame  69  constitute a glass window. 
     The manufacturing method for glass window includes, as shown in  FIG. 25 , the placing step S 1 , the bonding step S 2 , the treatment step S 3 , the cutting step S 4 , and the second bonding step S 6  included in the manufacturing method for the glass panel unit of the fifth embodiment, and additionally an assembling step S 8  of fitting a glass panel unit manufactured through the individual steps S 1 , S 2 , S 3 , S 4 , and S 6  into the window frame  69 . In the treatment step S 3 , air is evacuated from the inside space  4 . The second inside space  65  formed in the second bonding step S 6  is a space filled with the dry gas  600 . 
     The glass window manufactured by this method has a structure where the glass panel unit including the first space  41  and the second inside space  65  is fitted into the window frame  69 , and therefore has improved thermally insulating properties. 
     (Modifications) 
     Hereinafter, modifications of the glass panel units of the first to fifth embodiments are described. 
     As to the first to fifth embodiments, the vent  7  is formed in the second glass substrate  2 . However, it is sufficient that the vent  7  is formed in at least one of the first glass substrate  1  and the second glass substrate  2 . In more detail, the vent  7  may be formed in the first glass substrate  1 , or the vents  7  may be formed in both the first glass substrate  1  and the second glass substrate  2 . 
     As to the first and second embodiments, pressure of the inside space  4  is reduced until the inside space  4  becomes an evacuated space, and as to the third embodiment the inside space  4  is filled with the gas  400 . However, the inside space  4  may not have reduced pressure and may not be filled with the gas  400 . Also in this case, the inside space  4  is still between the first glass substrate  1  and the second glass substrate  2 , and therefore thermally insulating properties can be realized. 
     As to the first and third embodiments, the inside space  4  is partitioned into one first space  41  and one second space  42 , and as to the second embodiment, the inside space  4  is partitioned into two first spaces  41  and one second space  42 . However, how to partition the inside space  4  may not be limited to the above cases. Stated differently, the inside space  4  may be partitioned into one or more first spaces  41  and one or more second spaces  42  by the partition member  32 . It is possible to obtain, from the temporary-assembled unit  8 , multiple glass panel units the number of which is equal to the number of first spaces  41  partitioned from the inside space  4 . 
     As to the first to fifth embodiments the seal member  3  includes the partition member  32 , but may not include the partition member  32 . Also in this case, by cutting collectively the first glass substrate  1 , the seal member  3 , and the second glass substrate  2  along the cut plane  900  imaginary passing through the seal member  3 , it is possible to give a smooth sectional plane as if it is given by cutting one plate of glass. 
     Hereinbefore, the glass panel units of the first to fifth embodiments and the glass windows including these glass panel units are described with the attached drawings. Each embodiment may be modified appropriately according to design incentives, and one or more of components of the individual embodiments may be combined to apply to other embodiments. 
     As obviously understood from the aforementioned embodiments and modifications, the manufacturing method for glass panel unit according to the first aspect includes the placing step S 1 , the bonding step S 2 , and the cutting step S 4 . 
     The placing step S 1  is a step of placing a first glass substrate  1  and a second glass substrate  2  to face each other with a seal member  3  in-between. The bonding step S 2  is a step of bonding the first glass substrate  1  and the second glass substrate  2  to each other with the seal member  3 . The cutting step S 4  is a step of cutting the first glass substrate  1 , the seal member  3 , and the second glass substrate  2  collectively along a cut plane  900  imaginary passing through the seal member  3  from one of the first glass substrate  1  and the second glass substrate  2  bonded to each other. 
     According to the first aspect, by bonding the first glass substrate  1  and the second glass substrate  2  to each other to form the temporary-assembled unit  8  and then cutting the temporary-assembled unit  8 , the sealing furnace, glass panel units with various dimensions and shapes can be obtained. Therefore, it is possible to efficiently manufacture a glass panel unit with desired dimensions and shape, and also possible to obtain multiple glass panel units from one temporary-assembled unit  8 . 
     Note that, an increase in a redundant space inside the sealing furnace may cause a decrease in efficiency in manufacture. However, according to the first aspect, it is possible to suppress an increase in the redundant space inside the furnace by use of the sealing furnace suitable for the temporary-assembled unit  8 . Stated differently, in order to suppress an increase in the redundant space inside the furnace, there is no need to use a dedicated sealing furnace in accordance with a type (dimensions and shape) of a glass panel unit to manufacture. 
     Additionally, according to the first aspect, the first glass substrate  1  and the second glass substrate  2  bonded to each other with the seal member  3  are collectively and smoothly cut along the cut plane  900  which is imaginary and passes through the seal member  3 , as if a single plate of glass is cut. The sectional plane  811  resulting from cutting along the cut plane  900  is flat as with a sectional plane of a single plate of glass, and therefore strength can be ensured without additional processing, and handleability can be improved. 
     The manufacturing method for glass panel unit, of the second aspect, includes the elements of the first aspect and additional elements as follows. The second aspect further includes the wire cutting step S 5 . 
     The second glass substrate  2  is a glass substrate provided with a wire  25  embedded therein. The cutting step S 4  includes making a crack  61  propagate from the first glass substrate  1  to the second glass substrate  2  along the cut plane  900  imaginary to thereby break the first glass substrate  1 , the seal member  3 , and the second glass substrate  2  at the crack  61  with the second glass substrate  2  pointing inward. The wire cutting step S 5  is a step of cutting the wire  25  of the second glass substrate  2  subsequent to the cutting step S 4 . 
     According to the second aspect, strength of the second glass substrate  2  can be improved by the wire  25 , and therefore entire strength of the glass panel unit can be improved. Additionally, it is possible to suppress breakage which would otherwise occur in collectively cutting the first glass substrate  1  and the second glass substrate  2 . 
     The manufacturing method for glass panel unit, of the third aspect, includes the elements of the second aspect and additional elements as follows. In the third aspect, in the cutting step S 4  the first glass substrate  1  is positioned above the second glass substrate  2  and the crack  61  is made to propagate from an upper face of the first glass substrate  1 . 
     According to the third aspect, the crack  61  is made to develop by pressing the wheel  91  against the first glass substrate  1  from the above or the like. And, the first glass substrate  1  and the second glass substrate  2  are bent by lifting up part where the crack  61  develops relative to remaining part. Thereby, the first glass substrate  1 , the seal member  3 , and the second glass substrate  2  are cut collectively. 
     The manufacturing method for glass panel unit, of the fourth aspect, includes the elements of any of the first to third aspects, and additional elements as follows. In the fourth aspect, the seal member  3  includes a frame member  31  with a frame shape. The bonding step S 2  includes forming an inside space  4  enclosed by the frame member  31  between the first glass substrate  1  and the second glass substrate  2  bonded to each other with the frame member  31 . 
     According to the fourth aspect, the inside space  4  is positioned between the first glass substrate  1  and the second glass substrate  2 , and therefore this can lead to an increase in the thermally insulating properties of the glass panel unit. In other words, the fourth aspect enables efficiently manufacturing a glass panel unit with desired shape and dimensions and improved thermally insulating properties. 
     The manufacturing method for glass panel unit, of the fifth aspect, includes the elements of the fourth aspect, and additional elements as follows. The fifth aspect further includes a treatment step S 3  of evacuating air from the inside space  4  or supplying gas  400  to the inside space  4 . 
     According to the fifth aspect, the inside space  4  with a reduced pressure or filled with the gas  400  is positioned between the first glass substrate  1  and the second glass substrate  2 , and therefore this can lead to a further increase in the thermally insulating properties of the glass panel unit. In other words, the fifth aspect enables efficiently manufacturing a glass panel unit with desired shape and dimensions and improved thermally insulating properties. 
     The manufacturing method for glass panel unit, of the sixth aspect, includes the elements of the fifth aspect, and additional elements as follows. In the sixth aspect, the seal member  3  further includes a partition member  32  for partitioning the inside space  4  into multiple spaces  41 ,  42  ( 41   a ,  41   b ,  42 ). The cutting step S 3  includes cutting the first glass substrate  1 , the partition member  32 , and the second glass substrate  2  collectively along the cut plane  900  passing through the partition member  32 . 
     The sixth aspect enables efficiently manufacturing a glass panel unit with desired shape and dimensions and improved thermally insulating properties, by cutting the temporary-assembled unit  8  along the partition member  32 . 
     The manufacturing method for glass panel unit, of the seventh aspect, includes the elements of the sixth aspect, and additional elements as follows. In the seventh aspect, the bonding step S 2  includes bonding the first glass substrate  1  and the second glass substrate  2  to each other with the frame member  31  to partition the inside space  4  into the multiple spaces  41 ,  42  ( 41   a ,  41   b ,  42 ) by the partition member  32 . And, the bonding step S 2  includes providing one or more gas passages  43  ( 43   a ,  43   b ) for allowing gas move between the multiple spaces  41 ,  42  ( 41   a ,  41   b ,  42 ). The treatment step S 3  includes evacuating air from the inside space  4  or supplying gas  400  to the inside space  4  and then closing the one or more gas passages  43  ( 43   a ,  43   b ) to prevent movement of gas between the multiple spaces  41 ,  42  ( 41   a ,  41   b ,  42 ). The cutting step S 4  includes dividing the first glass substrate  1 , the partition member  32 , and the second glass substrate  2  collectively along the cut plane  900  passing through the partition member  32 . 
     Accordingly, the seventh aspect enables efficiently manufacturing a glass panel unit with desired shape and dimensions and improved thermally insulating properties. 
     The manufacturing method for glass panel unit, of the eighth aspect, includes the elements of the sixth aspect, and additional elements as follows. In the eighth aspect, at least one of the first glass substrate  1  and the second glass substrate  2  includes a vent  7 . The bonding step S 2  includes partitioning by the partition member  32  the inside space  4  into a first space  41  ( 41   a ,  41   b ) directly connected to the vent  7  and a second space  42  not directly connected to the vent  7 . Additionally the bonding step S 2  includes providing one or more gas passages  43  ( 43   a ,  43   b ) for allowing gas to move between the first space  41  ( 41   a ,  41   b ) and the second space  42 . 
     The treatment step S 3  includes evacuating air from the inside space  4  or supplying gas  400  to the inside space  4 , through the vent  7 , and then closing the one or more gas passages  43  ( 43   a ,  43   b ) to hermetically enclose the first space  41  ( 41   a ,  41   b ). The cutting step S 4  includes dividing the first glass substrate  1 , the partition member  32 , and the second glass substrate  2  into a part  81  including the first space  41  and a part  82  including the second space  42  and the vent  7 , by collectively cutting the first glass substrate  1 , the partition member  32 , and the second glass substrate  2  along the cut plane  900  passing through the partition member  32 . 
     According to the eighth aspect, the part  81  ( 81   a ,  81   b ) including the first space  41  ( 41   a ,  41   b ) which is the temporary-assembled unit  8  except for the part  82  including the second space  42  and the vent  7  can be provided as a glass panel unit with improved thermally insulating properties. 
     The manufacturing method for glass panel unit, of the ninth aspect, includes the elements of any of the fifth to eighth aspects, and additional elements as follows. The ninth aspect further includes a second bonding step S 6 . The second bonding step S 6  is a step of bonding one of the first glass substrate  1  and the second glass substrate  2  cut in the cutting step S 4  to a third glass substrate  63  with a second seal member  64  with a frame shape to form a second inside space  65  enclosed by the second seal member  64 . 
     According to the ninth aspect, the glass panel unit further including the second inside space  65  with thermally insulating properties can be obtained. In other words, the ninth aspect enables efficiently manufacturing the glass panel unit with more improved thermally insulating properties. 
     The manufacturing method for glass window, of the first aspect, includes an assembling step S 7  of fitting a glass panel unit manufactured by the manufacturing method for glass panel unit of any one of the fifth to eighth aspects, into a window frame  68 . The treatment step S 3  includes evacuating air from the inside space  4 . 
     Accordingly, the first aspect enables efficiently manufacturing a glass window with desired shape and dimensions and improved thermally insulating properties. 
     The manufacturing method for glass window, of the second aspect, includes the assembling step S 8  of fitting a glass panel unit manufactured by the manufacturing method for glass panel unit of the ninth aspect, into a window frame  69 . The treatment step S 3  includes evacuating air from the inside space  4 . The second inside space  65  formed in the second bonding step S 6  is a space filled with dry gas  600 . 
     Accordingly, the second aspect enables efficiently manufacturing a glass window with desired shape and dimensions and improved thermally insulating properties. 
     REFERENCE SIGNS LIST 
       1  Glass Panel Unit 
       11  Glass Substrate (First Glass Substrate) 
       111  Main Face 
       12  Glass Substrate (Second Glass Substrate) 
       13  Seal Member 
       14  Spacer 
       15  Inside Space 
       100  Glass Substrate with Spacer 
       2  Die 
       21  Penetrating Space 
       211  Penetrating Hole 
       3  Seat Member 
       31  Part 
       311  Portion 
       4  Punching Member 
       41  Punch 
       5  Substrate Support 
       9  Manufacturing Device 
     S 1  Setting Step 
     S 2  Spacer Forming Step 
     S 3  Moving Step 
     S 4  Assembling Step 
     S 5  Treatment Step