Abstract:
Provided are a glass film layered body and a method for manufacturing a glass film layered body whereby glass film yield and nondefective product rate are enhanced while handling properties of the glass film are enhanced. A method for manufacturing a glass film layered body fabricated by layering a glass film on a support glass, the method provided with an ultrasonic wave application step for applying ultrasonic waves to at least peripheral parts of the glass film and the support glass, a cleaning step for cleaning the glass film and support glass which have undergone the ultrasonic wave application step, and a layering step for layering the glass film on the support glass which has undergone the cleaning step and fabricating a glass film layered body.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is the U.S. national stage of application No. PCT/JP2014/076790, filed on Oct. 7, 2014. Priority under 35 U.S.C. §119(a) and 35 U.S.C. §365(b) is claimed from Japanese Application No. 2013-215398, filed Oct. 16, 2013, the disclosure of which is also incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to arts of a method for manufacturing a glass film laminate, a glass film laminate, and a method for manufacturing an electronic device. 
       BACKGROUND ART 
       [0003]    From a point of view of space-saving, instead of a CRT type display which had spread conventionally, a flat panel display such as a liquid crystal display, a plasma display, and an organic EL display spreads in recent. 
         [0004]    There is a need of making the flat panel display thinner. 
         [0005]    In recent, concerning a substrate and cover glass used for devices such as the flat panel display, a need of realizing further thinning and high flexibility is increased. 
         [0006]    For providing flexibility to a glass substrate, thinning of the glass substrate is effective, and the Patent Literature 1 proposes a glass film whose thickness is not more than 200 μm. 
         [0007]    Manufacturing relevant processes such as a machining process and a washing process is performed concerning the glass substrate used for an electronic device such as the flat panel display and a solar cell. 
         [0008]    However, when the glass substrate used for the electronic device is thinned, since grass is a brittle material, some change of stress causes damage, whereby there is a problem in that treatment is very difficult at the time of performing the manufacturing relevant processes of the electronic device. 
         [0009]    In addition, since the glass film whose thickness is not more than 200 μm has high flexibility, positioning at the time of performing the process is difficult and there is a problem in that a gap or the like occurs at the time of patterning. 
         [0010]    For improving handling of the thinned glass film, the Patent Literature 1 proposes a glass film laminate in which the glass film is laminated on support glass. 
         [0011]    According to the glass film laminate, even when the glass film which lacks intensity and rigidity alone is used, since rigidity of the support glass is high, positioning of the whole glass film laminate at the time of performing the process is easy. 
         [0012]    After finishing the process, the glass film can be exfoliated from the support glass. 
         [0013]    When a thickness of the glass film laminate is the same as a thickness of the conventional glass substrate, an electronic device can be manufactured with an electronic device manufacturing line for the conventional glass substrate. 
       PRIOR ART REFERENCE 
     Patent Literature 
       [0014]    Patent Literature 1: the Japanese Patent Laid Open Gazette 2011-183792 
       DISCLOSURE OF INVENTION 
     Problems to be Solved by the Invention 
       [0015]    In the case of manufacturing the electronic device such as a liquid crystal panel with the glass film laminate shown in the Patent Literature 1, generally, a step in which resist liquid is applied to the glass film laminate (resist step) is provided. The resist liquid applied to the glass film laminate in the resist step is solidified by a method such as photosensitizing, heating or drying. 
         [0016]    In the conventional glass film laminate  1  shown in the Patent Literature 1, as shown in FIG.  16 , bubbles  14  may be formed in an interface  13  of the glass film  10  and a support glass  12  which is the support body  11 . The bubbles  14  include a bubble communicated with atmosphere at an outer peripheral edge of the glass film  10 . Hereinafter, such the bubble  14  is referred to as an open bubble  14   a.    
         [0017]    In the glass film laminate  1  in which the open bubble  14   a  exists in the interface  13 , there is a problem in that the resist liquid applied in the resist step enters the open bubble  14   a.    
         [0018]    Since the resist liquid entering the open bubble  14   a  is then solidified, there is a problem in that the glass film  10  and the support glass  12  in a part in which the open bubble  14   a  exists are made adhere each other by the solidified resist liquid. 
         [0019]    Furthermore, in the glass film laminate  1  adhered by the resist liquid, at the time of separating the support glass  12  and the glass film  10 , there is a problem in that the adhered part is hard to be exfoliated so as to cause damage of the glass film  10 , whereby a yield of the glass film  10  is worsened and a non-defective rate of the glass film  10  obtained from the glass film laminate  1  is worsened. 
         [0020]    Accordingly, it is desired that occurrence of damage at the time of exfoliating the glass film is suppressed by preventing the adhesion of the support glass and the glass film by the resist liquid so as to improve the yield and the non-defective rate of the glass film. 
         [0021]    The present invention is provided in consideration of the conditions as mentioned above, and the purpose of the invention is to provide a glass film laminate a method for manufacturing the glass film laminate in which generation of an open bubble in a laminating interface of the glass film laminate is prevented while improving handling of a glass film so as to improve a yield and a non-defective rate of the glass film. 
       Means for Solving the Problems 
       [0022]    The problems to be solved by the present invention have been described above, and subsequently, the means of solving the problems will be described below. 
         [0023]    The first invention of the application is a method for manufacturing a glass film laminate produced by laminating a glass film on a support body including an ultrasonic wave application step in which an ultrasonic wave is applied to at least peripheral parts of the glass film and the support body, a washing step in which the glass film and the support body passing through the ultrasonic wave application step are washed, and a laminating step in which the glass film and the support body passing through the washing step are laminated so as to produce the glass film laminate. 
         [0024]    According to the second invention of the application, the support body is support glass. 
         [0025]    According to the third invention of the application, in the ultrasonic wave application step, the ultrasonic wave is applied by a horn-type ultrasonic wave generator. 
         [0026]    According to the fourth invention of the application, in the ultrasonic wave application step, the ultrasonic wave is applied to only the peripheral parts of the glass film and the support glass. 
         [0027]    According to the fifth invention of the application, in an ultrasonic wave washing step, the glass film and the support body are dipped in liquid in an ultrasonic wave washing tub and the whole of the glass film and the support glass are ultrasonic-washed by the ultrasonic wave washing tub. 
         [0028]    The sixth invention of the application further includes an open bubble inspection step inspecting existence of an open bubble which is a bubble existing in an interface of the glass film and the support body and contacting an edge side of the glass film. 
         [0029]    According to the seventh invention of the application, in the open bubble inspection step, existence of a bubble except for the open bubble in a peripheral part of the glass film laminate corresponding to the peripheral part of the glass film is inspected further. 
         [0030]    According to the eighth invention of the application, the peripheral part of the glass film laminate is within a width of not less than 10 mm from the edge side of the glass film. 
         [0031]    According to the ninth invention of the application, a number of bubbles in the glass film laminate except for the peripheral part is not less than 0.1/m 2  and not more than 10000/m 2 . 
         [0032]    The tenth invention of the application is a glass film laminate produced by laminating directly a glass film and support glass, wherein all the edge sides of the glass film contact tightly the support glass. 
         [0033]    According to the eleventh invention of the application, the glass film contacts tightly the support glass with a width not less than 10 mm from all the edge sides of the glass film. 
         [0034]    According to the twelfth invention of the application, a number of bubbles in a part of the glass film laminate except for the part in which the glass film contacts tightly the support glass is not less than 0.1/m 2  and not more than 10000/m 2 . 
         [0035]    According to the thirteenth invention of the application, a thin film layer is provided in the support glass. 
         [0036]    The fourteenth invention of the application is a method for manufacturing an electronic device including a laminating step in which a glass film is laminated on a support body so as to produce the glass film laminate before a manufacturing relevant process of the electronic device, a step in which the manufacturing relevant process of the electronic device is performed to the glass film of the glass film laminate so as to form an element on the glass film of the glass film laminate and the element is closed by a closing substrate, thereby producing the electronic device with the support body, and a step in which the glass film of the electronic device with the support body after the manufacturing relevant process of the electronic device is exfoliated from the support body so as to manufacture the electronic device. In the laminating step, the glass film laminate is produced by the method for manufacturing the glass film laminate according to one of claims  1  to  8 . 
       Effect of the Invention 
       [0037]    The present invention brings the following effects. 
         [0038]    According to the first invention of the application, generation of the open bubble in the peripheral part of the glass film laminate can be prevented. 
         [0039]    Accordingly, penetration of the resist liquid to the interface of the glass film and the support body in the resist step can be prevented, and as a result, adhesion of the glass film and the support body can be prevented, thereby preventing damage of the glass film at the time of exfoliation. 
         [0040]    According to the second invention of the application, at the time of using the support grass as the support body, generation of the open bubble in the peripheral part of the glass film laminate can be prevented. 
         [0041]    According to the third invention of the application, foreign matters causing the normal open bubble can be removed certainly from the peripheral part of the glass film and the support body. 
         [0042]    According to the fourth invention of the application, time required for removing the foreign matters causing the normal open bubble can be shortened. 
         [0043]    According to the fifth invention of the application, the foreign matters causing the open bubble can be removed certainly from the peripheral parts of the glass film and the support body. 
         [0044]    By removing foreign matters in parts of the glass film and the support body except for the peripheral parts, a non-defective rate of the glass film can be improved. 
         [0045]    According to the sixth invention of the application, the glass film laminate in which the open bubble exists can be eliminated. 
         [0046]    Accordingly, a yield of the glass film after a manufacturing relevant process can be improved. 
         [0047]    According to the seventh invention of the application, generation of the open bubble after inspecting existence of the open bubble can be prevented. 
         [0048]    Accordingly, the yield of the glass film after a manufacturing relevant process can be improved certainly. 
         [0049]    According to the eighth invention of the application, generation of the open bubble in the peripheral part of the glass film laminate can be prevented certainly. 
         [0050]    According to the ninth invention of the application, generation of the close bubble at an inner side from the peripheral part of the glass film laminate can be prevented certainly while suppressing time and cost. 
         [0051]    According to the tenth invention of the application, penetration of the resist liquid to the interface of the glass film and the support body in the resist step can be prevented, and as a result, adhesion of the glass film and the support body can be prevented, thereby preventing damage of the glass film at the time of exfoliation. 
         [0052]    According to the eleventh invention of the application, the yield of the glass film can be improved. 
         [0053]    According to the twelfth invention of the application, generation of the close bubble at an inner side from the peripheral part of the glass film laminate can be prevented certainly while suppressing time and cost. 
         [0054]    According to the thirteenth invention of the application, the glass film can be exfoliated easily, whereby the yield of the glass film can be improved. 
         [0055]    According to the fourteenth invention of the application, a yield of the electronic device can be improved. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0056]      FIG. 1  is a schematic drawing of a method for manufacturing an electronic device (glass film) which includes a method for manufacturing a glass film laminate according to the present invention. 
           [0057]      FIG. 2  is a schematic drawing of a method for producing the glass film (overflow down draw method). 
           [0058]      FIG. 3  is a schematic perspective view of producing status of the glass film laminate. 
           [0059]      FIGS. 4A-B  are schematic drawings of a bonding mechanism of the glass film and a support glass.  FIG. 4A  is a drawing of status of hydrogen bond of hydroxyl groups, and  FIG. 4B  is a drawing of status of hydrogen bond in which a water molecule is interposed. 
           [0060]      FIG. 5  is a schematic drawing of another embodiment of the glass film laminate according to the present invention. 
           [0061]      FIG. 6  is a flow chart of the method for manufacturing the glass film laminate according to the present invention. 
           [0062]      FIG. 7  is a schematic drawing of components of the glass film laminate according to the present invention.  FIG. 7A  is a schematic plan view of the glass film, and  FIG. 7B  is a schematic plan view of the support glass. 
           [0063]      FIGS. 8A-B  are schematic drawings of the glass film laminate according to the present invention.  FIG. 8A  is a schematic plan view, and  FIG. 8B  is a schematic side view. 
           [0064]      FIG. 9  is a schematic perspective view of application status of an ultrasonic wave by a horn-type ultrasonic wave generator in the method for manufacturing the glass film laminate according to the present invention. 
           [0065]      FIG. 10  is a schematic plan view of the glass film laminate (in the state in which an open bubble exists in a peripheral part). 
           [0066]      FIG. 11  is a schematic plan view of the glass film laminate (in the state in which a close bubble exists in a peripheral part). 
           [0067]      FIG. 12  is a schematic plan view of the glass film laminate according to the present invention (in the state in which a close bubble exists at an inner side from a peripheral part). 
           [0068]      FIG. 13  is a schematic drawing of an electronic device with support glass which is an embodiment of the glass film laminate according to the present invention. 
           [0069]      FIG. 14  is a schematic plan view of penetration status of resist liquid to an open bubble in the glass film laminate. 
           [0070]      FIG. 15  is a diagram of results of an experiment confirming improvement status of a non-defective rate in the glass film laminate according to the present invention. 
           [0071]      FIG. 16  is a schematic plan view of a conventional glass film laminate in which an open bubble exists. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0072]    A suitable embodiment of a glass film laminate according to the present invention is explained referring to drawings. 
         [0073]    Firstly, a method for manufacturing a glass film laminate  1  according to the present invention is explained. 
         [0074]    In the method for manufacturing the glass film laminate  1  according to the present invention, as shown in  FIG. 1 , in a first step, a glass film  10  is laminated on a support body  11  so as to produce the glass film laminate  1 . 
         [0075]    Silicate glass and silica glass, preferably borosilicate, the most preferably non-alkali glass are used for the glass film  10 . 
         [0076]    When the glass film  10  includes alkali components, positive ions fall off from a surface of the film and so-called sodium blowing phenomenon occurs, whereby the structure becomes rough. In this case, when the glass film  10  is used while being bent, the part which becomes rough by deterioration with time may be broken. 
         [0077]    Herein, the non-alkali glass is glass which does not include alkali components (alkali metal oxides) substantially, and is concretely glass whose alkali components are not more than 3000 ppm. 
         [0078]    A content of the alkali components of the non-alkali glass used for the present invention is preferably not more than 1000 ppm, more preferably not more than 500 ppm, further more preferably not more than 300 ppm. 
         [0079]    A thickness of the glass film  10  is preferably not more than 300 μm, more preferably 5 to 200 μm, and the most preferably 5 to 100 μm. 
         [0080]    Accordingly, the glass film  10  can be made thinner so as to obtain suitably flexibility. 
         [0081]    The thinner glass film  10  is difficult to be handled and problems such as miss of positioning and bending at the time of patterning tend to occur. However, by using the support body  11  discussed later, manufacturing relevant processes such as patterning can be performed easily. 
         [0082]    When the thickness of the glass film  10  is less than 5 μm, strength of the glass film  10  is needy and the glass film  10  may be hard to be exfoliated from the support body  11 . 
         [0083]    A material of the support body  11  is not limited if it can support the glass film  10 , and a platy body such as a synthetic resin plate, a natural resin plate, a wood plate, a metal plate, a grass plate, a ceramic plate, a crystallized glass plate and the like can be used. A thickness of the support body  11  is not limited and may be selected suitably corresponding to rigidity of a material selected as the support body. For improving the handling of the glass film  10 , a resin film such as a PET film may be used. The support body  11  may be configured by providing suitably a resin layer discussed later on a surface of the platy body so as to control property of adhering to and exfoliating from the glass film  10 . 
         [0084]    Preferably, a support glass  12  is used for the support body  11 . Accordingly, characteristics and shapes of the glass film  10  and the support glass  12  are stable concerning heat treatment, chemical liquid treatment, exposure treatment and the like in the manufacturing relevant processes of an electronic device, whereby stable laminated state of the glass film laminate  1  can be maintained. 
         [0085]    Similarly to the glass film  10 , silicate glass and silica glass, borosilicate or non-alkali glass is used for the support glass  12 . 
         [0086]    As the support glass  12 , preferably, glass that a difference of thermal expansion coefficients with the glass film  10  at 30 to 380° C. is within 5×10 −7 /° C. is used. 
         [0087]    For suppressing the difference thermal expansion rates, the most preferably, glass of the same composition is used for both the glass film  10  and the support glass  12 . 
         [0088]    A thickness of the support glass  12  is preferably not less than 400 μm. When the thickness of the support glass  12  is less than 400 μm, problems may be caused by strength when the support glass  12  is dealt with alone. The thickness of the support glass  12  is preferably 400 to 700 μm, and the most preferably 500 to 700 μm. 
         [0089]    Accordingly, the glass film  10  can be supported certainly by the support glass  12 , and breakage of the glass film  10  occurring at the time of exfoliating the glass film  10  from the support glass  12  can be suppressed efficiently. 
         [0090]    At the time of applying resist liquid discussed later (third step), when the glass film laminate  1  is mounted on a setter (not shown), the thickness of the support glass  12  may be less than 400 μm (the same thickness as the glass film  10 , for example 300 μm). 
         [0091]    The glass film  10  and the support glass  12  used for the present invention are made preferably by a down draw method, and more preferably by an overflow down draw method. 
         [0092]    Especially, the overflow down draw method shown in  FIG. 2  is a forming method in which both surfaces of a glass plate do not contact forming members and the both surfaces (translucent surface) of the obtained glass plate is hardly damaged, whereby high surface quality without polish. Of course, the glass film  10  and the support glass  12  used for the present invention may be formed by a float method, a slot downdraw method, a roll out method, an updraw method, redraw method or the like. 
         [0093]    In the overflow down draw method shown in  FIG. 2 , a grass ribbon G just after flowing down from a lower end  21  of a molding body  20  whose sectional shape is wedge-like is extended downward while expansion and contraction in a width direction of the grass ribbon G is restricted by cooling rollers  22  so as to be made thin to a predetermined thickness. Next, the grass ribbon G with the predetermined thickness is cooled gradually by a slow cooling furnace (annealer) so as to remove heat distortion of the grass ribbon G, and the grass ribbon G is cut into a predetermined size, whereby the glass film  10  and the support glass  12  are formed respectively. 
         [0094]    An embodiment in which the support glass  12  is adopted as the support body  11  is explained. In the parts except for characteristic explanations resulting from a material of the support glass  12 , the support glass  12  can be suitably read as the support body  11 . 
         [0095]    As shown in  FIG. 3 , a contact surface  10   a  and an effective surface  10   b  are set in the glass film  10 . 
         [0096]    The contact surface  10   a  faces and contacts the support glass  12  at the time of being laminated with the support glass  12 . 
         [0097]    The effective surface  10   b  is opposite to the contact surface  10   a  and the manufacturing relevant processes such as forming of elements are performed therein. 
         [0098]    A contact surface  12   a  and a conveyance surface  12   b  are set in the support glass  12 . 
         [0099]    The contact surface  12   a  faces and contacts the glass film  10  at the time of being laminated with the glass film  10 . 
         [0100]    The conveyance surface  12   b  is opposite to the contact surface  12   a  and contacts conveyance rollers when the glass film laminate  1  is conveyed on the conveyance rollers. 
         [0101]    Though the glass film  10  having substantially the same area as the support glass  12  is laminated on the support glass  12  in  FIG. 3 , the support glass  12  may overflow the glass film  10 . 
         [0102]    In this case, an overflow amount of the support glass  12  from the glass film  10  is preferably 0.5 to 10 mm, and more preferably 0.5 to 1 mm. 
         [0103]    By making the overflow amount of the support glass  12  small, an area of the effective surface  10   b  of the glass film  10  can be secured more widely. 
         [0104]    The step laminating the glass film  10  on the support glass  12  may be performed under decompression. Accordingly, bubbles generated between the glass film  10  and the support glass  12  when the glass film  10  and the support glass  12  are laminated can be reduced. 
         [0105]    A surface roughness Ra of each of the contact surface  10   a  of the glass film  10  and the contact surface  12   a  of the support glass  12  is preferably not more than 2.0 nm. Accordingly, the glass film contacts the support glass with smooth surfaces so as to improve the adhesion, whereby the glass film and the support glass can be laminated firmly stably without any bonding agent. 
         [0106]    For laminating firmly stably the glass film  10  and the support glass  12  without any bonding agent, the surface roughness Ra of each of the contact surfaces  10   a  and  12   a  of the glass film  10  and the support glass  12  used in the present invention is preferably not more than 1.0 nm, more preferably not more than 0.5 nm, and the most preferably not more than 0.2 nm. 
         [0107]    In this embodiment, the surface roughness Ra of each of the surfaces of the glass film  10  and the support glass  12  contacting each other is not more than 2.0 nm, and in the first step, the glass film  10  and the support glass  12  each of whose surfaces contacting each other is not more than 2.0 nm are laminated and the glass film  10  is fixed firmly to the support glass  12 , whereby the glass film laminate  1  is produced. 
         [0108]    By smoothing the contact surfaces  10   a  and  12   a  of the glass film  10  and the support glass  12  so as to make the surface roughness Ra thereof not more than 2.0 nm, when the two smooth glass plates contact tightly each other, the glass plates are made adhere detachably without any bonding agent, whereby the glass film laminate  1  is configured. It is guessed that this phenomenon is based on following mechanism. 
         [0109]    As shown in  FIG. 4A , it is thought that the surface of the glass film  10  (the contact surface  10   a ) and the surface of the support glass  12  (the contact surface  12   a ) are attracted to each other by hydrogen bond of hydroxyl groups formed thereon. Otherwise, as shown in  FIG. 4B , it is thought that the glass film  10  and the support glass  12  are made adhere each other by forming hydrogen bond of water molecules existing in an interface  13  of the glass film  10  and the support glass  12 . 
         [0110]    Though the glass film  10  is laminated directly on the support glass  12  in this embodiment, it may be configured that a thin film layer  15  is formed on the support glass  12  and then the glass film  10  is laminated as shown in  FIG. 5 . Preferably, inorganic oxide such as ITO and ZrO 2 , nitride such as SiN x , TiN, CrN, TiAlN and AlCrN, metal such as Ti, carbide such as diamond-like carbon, TiC and WC, or fluoride such as MgF 2  is used for the thin film layer  15 . In this case, a surface roughness Ra of the thin film layer  15  is preferably not more than 2.0 nm, not more than 1.0 nm, not more than 0.5 nm or not more than 0.2 nm in this order. Resin may be used for the thin film layer  15 , and in this case, since the glass film  10  is exfoliated finally, a slightly adhesive film is preferably used as the thin film layer  15  formed on the support glass  12 . In this case, polyethylene, polyvinyl chloride, polyethylene terephthalate, polyvinylidene chloride, polypropylene, poly vinyl alcohol, polyester, polycarbonate, polystyrene, polyacrylonitrile, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-methacrylic acid copolymer, nylon, cellophane, silicone resin and the like can be used. As the thin film layer  15 , only a base material may be used when the material is adhesive, a base material whose surfaces are applied thereto with a bonding agent, or an adhesive layer without any base material may be used. 
         [0111]    On the other hand, a surface roughness of the effective surface  10   b  of the glass film  10  is not limited especially. However, since a forming step of elements and the like are performed in a third step discussed later, the surface roughness Ra of the effective surface  10   b  is preferably not more than 2.0 nm, more preferably not more than 1.0 nm, further more preferably not more than 0.5 nm, and the most preferably not more than 0.2 nm. A surface roughness of the conveyance surface  12   b  of the support glass  12  is not limited especially. 
         [0112]    As shown in  FIGS. 1 and 6 , the method for manufacturing the glass film laminate  1  according to the present invention is characterized in that, in the first step, before a laminating step (STEP- 1 - 3 ) in which the glass film  10  and the support glass  12  are laminated directly so as to produce the glass film laminate  1 , an ultrasonic wave application step (STEP- 1 - 1 ) in which an ultrasonic wave US is applied to the glass film  10  and the support glass  12  and a washing step (STEP- 1 - 2 ) in which foreign matters adhering the glass film  10  and the support glass  12  after the ultrasonic wave application step (STEP- 1 - 1 ) are washed and removed are provided. 
         [0113]    The ultrasonic wave application step (STEP- 1 - 1 ) and the washing step (STEP- 1 - 2 ) prevent generation of an open bubble in the interface  13  of the glass film laminate  1 . 
         [0114]    As shown in  FIG. 16 , when foreign matters exist in the interface  13  at the time of laminating the glass film  10  and the support glass  12 , the glass film  10  and the support glass  12  are not adhered partially by the foreign matters, whereby bubbles  14  may be formed in the interface  13  of the glass film laminate  1 . 
         [0115]    Namely, by removing certainly the foreign matters on the contact surface  10   a  of the glass film  10  and the contact surface  12   a  of the support glass  12 , generation of the bubbles  14  in the interface  13  can be prevented. 
         [0116]    As shown in  FIG. 16 , among the bubbles  14 , an open bubble  14   a  which is the bubble  14  contacting an edge side  10   c  of the glass film  10  and a close bubble  14   b  which is the bubble  14  not contacting the edge side  10   c  of the glass film  10  exist. 
         [0117]    Among the bubbles  14  existing in the interface  13  of the glass film  10  and the support glass  12 , the open bubble  14   a  contacts the edge side  10   c  of the glass film  10  and is communicated with the outside. The close bubble  14   b  does not contact the edge side  10   c  of the glass film  10  and is not communicated with the outside. 
         [0118]    In the method for manufacturing the glass film laminate  1  according to the present invention, as shown in  FIGS. 7A and 7B , remove of the foreign matters in the ultrasonic wave application step (STEP- 1 - 1 ) and the washing step (STEP- 1 - 2 ) is performed concerning at least the peripheral parts  10   d  and  12   d  of the glass film  10  and the support glass  12 . 
         [0119]    As shown in  FIG. 7A , the peripheral part  10   d  of the glass film  10  is a range within a predetermined width L from the four edge sides  10   c  in the contact surface  10   a  of the glass film  10  (a range to which lines upward slanting to the right are applied), and as shown in  FIG. 7B , the peripheral part  12   d  of the support glass  12  is a range within a predetermined width M from four edge sides  12   c  in the contact surface  12   a  of the support glass  12  (a range to which lines upward slanting to the left are applied). 
         [0120]    As shown in  FIG. 8A , an overlapping range of the peripheral parts  10   d  and  12   d  (a range of a predetermined width N to which slanting lines are applied shading-like) is specified as a peripheral part  1   d  of the glass film laminate  1 . 
         [0121]    The peripheral part  10   d  of the glass film  10  does not need to be completely in agreement with the peripheral part  12   d  of the support glass  12 . The peripheral part  10   d  of the glass film  10  may overflow the peripheral part  12   d  of the support glass  12 , and on the contrary, the peripheral part  12   d  of the support glass  12  may overflow the peripheral part  10   d  of the glass film  10 . 
         [0122]    There is an especially high possibility that the foreign matters existing in the peripheral part  1   d  become a factor of the open bubble  14   a . There is a high possibility that the close bubble  14   b  owing to the foreign matters existing in the peripheral parts  10   d  and  12   d  changes to the open bubble  14   a  by shifting its position by stress from the outside or change with time. 
         [0123]    Namely, for preventing the open bubble  14   a  certainly, forming of the close bubble  14   b  in the peripheral part  1   d  must be prevented. 
         [0124]    Accordingly, in the method for manufacturing the glass film laminate  1  according to the present invention, the foreign matters in the peripheral parts  10   d  and  12   d  are certainly removed by the ultrasonic wave application step (STEP- 1 - 1 ) and the washing step (STEP- 1 - 2 ), whereby no foreign matter exists in the peripheral part  1   d . The glass film laminate  1  according to the present invention is produced so that the open bubble  14   a  does not exist in the peripheral part  1   d , and as shown in  FIG. 8B , the edge sides  10   c  of the glass film  10  contact closely to the contact surface  12   a  of the support glass  12 . 
         [0125]    A number of the close bubbles  14   b  except for the peripheral part  10   d  is preferably small. 
         [0126]    Concretely, the number of the close bubbles  14   b  whose diameter converted to a circle is not less than 5 mm is preferably not more than 10000/m 2 , more preferably not more than 1000/m 2 , further more preferably not more than 100/m 2 , and the most preferably not more than 10/m 2 . 
         [0127]    That is because since smoothness is required at the time of performing the manufacturing relevant processes of the element (electronic device), the number of the close bubble  14   b  except for the peripheral part  10   d  is preferably small. 
         [0128]    The number of the close bubbles  14   b  except for the peripheral part  10   d  is preferably not less than 0.1/m 2 . 
         [0129]    That is because time for washing and the like is required for lessening the number of the close bubbles  14   b  except for the peripheral part  10   d  as much as possible and cost for producing the glass film laminate may be increased. The number of the close bubbles  14   b  except for the peripheral part  10   d  is preferably not less than 0.5/m 2 , more preferably not less than 1/m 2 , further more preferably not less than 2/m 2 . 
         [0130]    The predetermined width N of the peripheral part  1   d  of the glass film laminate  1  according to this embodiment is 10 mm, and the predetermined width N of the glass film laminate according to the present invention is preferably not less than 10 mm. 
         [0131]    That is because there is an especially high possibility that the bubble  14  generated at a position whose distance from the edge side  10   c  of the glass film  10  is less than 10 mm becomes the open bubble  14   a , and there is a possibility that the close bubble  14   b  generated in this range changes to the open bubble  14   a  by shifting its position by stress from the outside or change with time. 
         [0132]    Furthermore, that is because the foreign matters existing 10 mm or more inner side from the edge side  10   c  is hardly become the factor of the open bubble  14   a.    
         [0133]    The range to which the ultrasonic wave US is applied in the ultrasonic wave application step (STEP- 1 - 1 ) may include a part at an inner side from the peripheral parts  10   d  and  12   d  (the range of the predetermined widths L and M shown in  FIGS. 7A and 7B ), or the ultrasonic wave US may be applied to a whole surface (whole range) of the glass film  10  and the support glass  12 . 
         [0134]    That is because by removing the foreign matters existing at the inner side from the peripheral parts  10   d  and  12   d , a non-defective rate of the glass film  10  can be improved. 
         [0135]    As shown in  FIG. 9 , in the method for manufacturing the glass film laminate  1  according to the present invention, a horn-type ultrasonic wave generator  30  is used as a means applying the ultrasonic wave US to the glass film  10  and the support glass  12 . 
         [0136]    In comparison with a tub-type ultrasonic wave generator, the horn-type ultrasonic wave generator  30  can apply partially the stronger ultrasonic wave US, thereby being suitable for removing foreign matters adhering the surfaces of the glass film  10  and the support glass  12 . Especially, by using the horn-type ultrasonic wave generator  30 , grass powder adhering to the surfaces which cannot be removed by normal scrubbing can be removed. 
         [0137]    Since an operator can select and scan a position to which the ultrasonic wave US is applied simultaneously by the horn-type ultrasonic wave generator  30 , a part of the glass film  10  and the support glass  12  in which the foreign matters become the factor of the open bubble  14   a  (that is, the range of the predetermined widths L and M) can be selected preferentially and the ultrasonic wave US can be applied thereto. 
         [0138]    According to the configuration in which the ultrasonic wave US is applied to only the range of the predetermined widths L and M by the horn-type ultrasonic wave generator  30 , time required for a work applying the ultrasonic wave US can be shortened, whereby generation of the open bubble  14   a  can be prevented efficiently. 
         [0139]    In the method for manufacturing the glass film laminate  1  according to the present invention, when the ultrasonic wave US is applied to the glass film  10  and the support glass  12  in the ultrasonic wave application step (STEP- 1 - 1 ), the glass film  10  and the support glass  12  are arranged in a tub  32  filled with liquid  31  and the ultrasonic wave US is applied to the glass film  10  and the support glass  12  while being dipped in the liquid  31 . 
         [0140]    In this embodiment, pure water is used as the liquid  31  in which the glass film  10  and the support glass  12  are dipped. Liquid except for the pure water such as ethanol may be used as the liquid  31  in which the glass film  10  and the support glass  12  are dipped. 
         [0141]    In the method for manufacturing the glass film laminate  1  according to the present invention, it may be configured that an ultrasonic wave washing tub is used as the tub  32  and an ultrasonic wave washing process is provided further. Namely, the ultrasonic wave may be applied to the whole of the glass film  10  and the support glass  12  by the tub (ultrasonic wave washing tub)  32  before, after or midst applying the ultrasonic wave US to the glass film  10  and the support glass  12  by the horn-type ultrasonic wave generator  30 . 
         [0142]    According to the configuration in which the ultrasonic wave is applied to the range of the predetermined widths L and M by the horn-type ultrasonic wave generator  30  while the ultrasonic wave is applied to the whole of the glass film  10  and the support glass  12 , the foreign matters adhering the whole range of the whole of the glass film  10  and the support glass  12  can be removed in addition to preventing generation of the open bubble  14   a  in the peripheral part  1   d , whereby the non-defective rate of the glass film  10  can be improved. 
         [0143]    As shown in  FIGS. 1 and 6 , the method for manufacturing the glass film laminate  1  according to the present invention includes an open bubble inspection step (STEP- 2 ) which is a second step in which whether the open bubble  14   a  exists in the peripheral part  1   d  of the glass film laminate  1  or not after producing the glass film laminate  1 . 
         [0144]    In the open bubble inspection step (STEP- 2 ), the glass film laminate  1  in which the open bubble  14   a  exists in the peripheral part  1   d  as shown in  FIG. 10  is eliminated as a defective product. 
         [0145]    As the open bubble inspection step (STEP- 2 ), in addition to visual inspection, optical inspection using suitably an edge light, a microscope, a line camera or the like can be used. 
         [0146]    Namely, the method for manufacturing the glass film laminate  1  according to the present invention includes further the open bubble inspection step (STEP- 2 ) inspecting existence of the open bubble  14   a  contacting the edge side  10   c  of the glass film  10  among the bubbles  14  existing in the interface  13  of the glass film  10  and the support glass  12 . 
         [0147]    According to the configuration, the glass film laminate  1  in which the open bubble  14   a  can be eliminated, whereby a yield of the glass film  10  can be improved. 
         [0148]    In the method for manufacturing the glass film laminate  1  according to the present invention, it may be configured that existence of not only the open bubble  14   a  in the peripheral part  1   d  but also the close bubble  14   b  in the peripheral part  1   d  is inspected in the open bubble inspection step (STEP- 2 ). 
         [0149]    The close bubble  14   b  does not contact the edge side  10   c  of the glass film  10  and has a possibility to move to a position contacting the edge side  10   c  by change with time or external force at the time of the inspection, and has a possibility to change to the open bubble  14   a  after the inspection. 
         [0150]    Accordingly, in the method for manufacturing the glass film laminate  1  according to the present invention, in (STEP- 2 ), the glass film laminate  1  in which the close bubble  14   b  exists in the peripheral part  1   d  as shown in  FIG. 11  is eliminated as a defective product. 
         [0151]    On the other hand, in the open bubble inspection step (STEP- 2 ), the glass film laminate  1  in which the bubble  14  (the close bubble  14   b ) exists at an inner side from the peripheral part  1   d  as shown in  FIG. 12  is treated as a non-defective product. 
         [0152]    The glass film laminate  1  which is judged to be a defective product in the open bubble inspection step (STEP- 2 ) is separated into the glass film  10  and the support glass  12  and returned to the first step so as to be reused. 
         [0153]    In a third step shown in  FIG. 1 , the manufacturing relevant process of an electronic device is performed.  FIG. 13  is a drawing of an electronic device  40  with support glass. An element  41  such as liquid crystal, organic EL or a solar cell is formed on the glass film  10  of the glass film laminate  1 . As shown in  FIG. 1 , in the forming of the element  41 , for protecting partially the element  41 , resist liquid  42  is applied to the glass film laminate  1 . The resist liquid  42  is solidified by a method such as photosensitizing, drying or heating. 
         [0154]    At this time, if the open bubble  14   a  exists in the interface  13  of the glass film laminate  1  as shown in  FIG. 14 , the resist liquid  42  penetrates the open bubble  14   a  and then solidified by the method such as photosensitizing or drying, whereby the glass film  10  and the support glass  12  are made adhere each other. Accordingly, in the open bubble inspection step (STEP- 2 ), the glass film laminate  1  having the open bubble  14   a  is eliminated as a defective product. 
         [0155]    The element  41  is closed by cover glass  43 , and if the device is a liquid crystal panel, liquid crystal is injected (not shown), whereby the electronic device  40  with the support glass is formed. 
         [0156]    Though the cover glass  43  and the glass film  10  are made adhere directly each other in the mode shown in  FIG. 13 , the cover glass  43  and the glass film  10  may be made adhere suitably via glass frit, a spacer or the like. 
         [0157]    As a closing substrate closing the element  41 , the cover glass  43  made by silicate glass and silica glass, borosilicate or non-alkali glass similarly to the glass film  10  is used. 
         [0158]    As the cover glass  43 , preferably, glass with a coefficient of linear thermal expansion whose difference with the glass film  10  at 30 to 380° C. is within 5×10 −7 /° C. 
         [0159]    Accordingly, when temperature of a surrounding environment of a produced electronic device  50  is changed, warp by heat and breakage of the glass film  10  and the cover glass  43  caused by the difference of the coefficient of linear thermal expansion hardly occur, whereby the electronic device  50  is hard to be damaged. 
         [0160]    For suppressing the difference of the coefficient of linear thermal expansion, the most preferably, glass of the same composition is used for both the cover glass  43  and the glass film  10 . 
         [0161]    A thickness of the cover glass  43  is preferably not more than 300 μm, more preferably 5 to 200 μm, and the most preferably 5 to 100 μm. Accordingly, the cover glass  43  can be made thinner so as to obtain suitably flexibility. When the thickness of the cover glass  43  is less than 5 strength of the cover glass  43  is needy. 
         [0162]    Next, in a fourth step, in the electronic device  40  with the support glass, the glass film  10  is exfoliated from the support glass  12 , whereby the electronic device  50  which is the glass film  10  in which the element  41  is formed is produced. 
         [0163]    As shown in  FIG. 1 , in the fourth step according to the present invention, the electronic device  40  with the support glass is separated into the electronic device  50  (the glass film  10 ) and the support glass  12 . 
         [0164]    When the electronic device  50  is exfoliated from the support glass  12 , an edge of the glass film  10  is pulled so as to be separated from the support glass  12  while a wedge (not shown) is inserted into the interface  13  of the glass film  10  and the support glass  12 , whereby the electronic device  50  (the glass film  10 ) is exfoliated. 
         [0165]    Supposing, in the glass film laminate  1  in which the glass film  10  and the support glass  12  are made adhere each other as shown in  FIG. 14 , at the time of exfoliating the glass film  10  from the support glass  12 , stress is concentrated to an adhesion part by the resist liquid  42 , whereby there is a high possibility that the glass film  10  is damaged with the adhesion part as a starting point. 
         [0166]    On the other hand, in the mode in which generation of the open bubble  14   a  at the peripheral part  1   d  is prevented as the glass film laminate  1  according to the present invention (see  FIGS. 8 and 12 ), since the resist liquid  42  does not penetrate the interface  13  so that adhesion of the glass film  10  and the support glass  12  caused by the solidified resist liquid  42  does not occur, whereby the glass film  10  is not damaged at the time of exfoliation. 
         [0167]    As shown in  FIG. 1 , the support glass  12  (the support body  11 ) exfoliated in the fourth step can be returned to the first step so as to be reused for producing the glass film laminate  1 . 
         [0168]    According to the configuration of suppressing damage of the glass film  10  as the method for manufacturing the glass film laminate  1  according to the present invention, a reuse rate of the support glass  12  can be improved, thereby reducing a cost of the glass film laminate  1 . 
         [0169]    As explained above, the method for manufacturing the glass film laminate  1  according to the present invention is the method for manufacturing the glass film laminate  1  which is produced by laminating the glass film  10  and the support glass  12 , and includes the ultrasonic wave application step (STEP- 1 - 1 ) in which the ultrasonic wave US is applied to at least the peripheral parts  10   d  and  12   d  of the glass film  10  and the support glass  12 , the washing step (STEP- 1 - 2 ) in which the glass film  10  and the support glass  12  passing through the ultrasonic wave application step (STEP- 1 - 1 ) are washed, and the laminating step (STEP- 1 - 3 ) in which the glass film  10  and the support glass  12  passing through the washing step (STEP- 1 - 2 ) are laminated so as to produce the glass film laminate  1 . 
         [0170]    According to the configuration, generation of the open bubble  14   a  in the peripheral part  1   d  of the glass film laminate  1  can be prevented. 
         [0171]    Accordingly, penetration of the resist liquid  42  to the interface  13  of the glass film  10  and the support glass  12  in the resist step (third step) can be prevented, and as a result, adhesion of the glass film  10  and the support glass  12  can be prevented, thereby preventing damage of the glass film  10  at the time of exfoliation. 
         [0172]    Next, results of an experiment confirming effect the method for manufacturing the glass film laminate  1  according to the present invention are explained. 
         [0173]    In this experiment, a thin plate glass made by Nippon Electric Glass Company, Limited (product name: OA-10G) is used. A plate glass of 350 mm×450 mm×0.2 mm is used as the glass film, and a plate glass of 360 mm×460 mm×0.5 mm is used as the support glass. Using the glass film and the support glass of the above specifications, the 100 glass film laminates are produced respectively concerning total four kinds including the glass film laminates  1  according to examples 1 to 3 and the glass film laminate  1  according to a comparative example 1 intermingled at an optional rate. 
         [0174]    Washing of the contact surfaces  10   a  and  12   a  are performed by rubbing the glass film  10  and the support glass  12  with sponge made from urethane while applying washing liquid to which alkaline detergent is added. 
         [0175]    The ultrasonic wave (frequency 25 kHz) is applied to only the peripheral parts  10   d  and  12   d  of the glass film  10  and the support glass  12  for 30 seconds by the horn-type ultrasonic wave generator (tip area 20×80 mm), and then the contact surfaces  10   a  and  12   a  are washed and subsequently laminated directly, whereby the glass film laminate  1  according to the example 1 is produced. 
         [0176]    Quality judging of the glass film laminate  1  according to the example 1 is performed only by the number of the bubbles  14  in the interface  13 . 
         [0177]    In the inspection by the number of the bubbles  14  in the interface  13 , the product in which the number of the bubbles  14  is not more than 100/m 2  is judged to be a non-defective product (the same applies to the following). 
         [0178]    The ultrasonic wave (frequency 25 kHz) is applied to contact surfaces  10   a  and  12   a  (whole surfaces) of the glass film  10  and the support glass  12  for 30 seconds by the horn-type ultrasonic wave generator (the same as the above), and then the contact surfaces  10   a  and  12   a  are washed and subsequently laminated directly, whereby the glass film laminate  1  according to the example 2 is produced. 
         [0179]    Quality judging of the glass film laminate  1  according to the example 2 is performed only by the number of the bubbles  14  in the interface  13 . 
         [0180]    The ultrasonic wave (frequency 25 kHz) is applied to the contact surfaces  10   a  and  12   a  (whole surfaces) of the glass film  10  and the support glass  12  for 30 seconds by the horn-type ultrasonic wave generator (the same as the above), and then the contact surfaces  10   a  and  12   a  are washed and subsequently laminated directly, whereby the glass film laminate  1  according to the example 3 is produced. 
         [0181]    Quality judging of the glass film laminate  1  according to the example 3 is performed firstly by counting the number of the bubbles  14  in the interface  13 , and the quality judging is performed further by inspecting existence of the open bubble  14   a  and the close bubble  14   b  in the peripheral part  1   d  (L=10 mm). 
         [0182]    On the other hand, the glass film laminate  1  according to the comparative example 1 is produced by washing of the contact surfaces  10   a  and  12   a  and subsequent direct lamination without application of the ultrasonic. 
         [0183]    Quality judging of the glass film laminate  1  according to the comparative example 1 is performed only by the number of the bubbles  14  in the interface  13 . 
         [0184]      FIG. 15  shows results of difference of the non-defective rate of the panels as final products in the case in which the quality judging is performed concerning the glass film laminates  1  according to the examples 1 to 3 and the comparative example 1 as the above. 
         [0185]    In the case of the glass film laminate  1  according to the example 1, as a result of the judgement only by existence of the bubbles  14  in the interface  13 , one defective product exists in the final panels and a final panel non-defective rate is 99%. 
         [0186]    In the case of the glass film laminate  1  according to the example 2, as a result of the judgement only by existence of the bubbles  14  in the interface  13 , two defective products exist in the final panels and the final panel non-defective rate is 98%. 
         [0187]    In the case of the glass film laminate  1  according to the example 3, as a result of the judgement by existence of the bubbles  14  in the interface  13  and existence of the open bubble  14   a  and the close bubble  14   b  in the peripheral part  1   d , no defective product exists in the final panels and a final panel non-defective rate is 100%. 
         [0188]    On the other hand, in the case of the glass film laminate  1  according to the comparative example 1, as a result of the judgement only by existence of the bubbles  14  in the interface  13 , ten defective products exist in the final panels and the final panel non-defective rate is 89%. 
         [0189]    According to the results of the experiment shown in  FIG. 15 , in comparison with the case of not applying the ultrasonic wave US (that is, the case of the comparative example 1), by applying the ultrasonic wave US to the glass film  10  and the support glass  12 , washing them and then producing the glass film laminate  1  as the glass film laminates  1  according to the examples 1 to 3, more number of the non-defective products of the final panels can be obtained. 
         [0190]    According to the results of the experiment, as the glass film laminate  1  according to the example 3, by confirming that the open bubble  14   a  and the close bubble  14   b  do not exist in the peripheral part  1   d , a yield of the final product can be improved further. 
       DESCRIPTION OF NOTATIONS 
       [0000]    
       
         
           
               1  glass film laminate 
               1   d  peripheral part 
               10  glass film 
               10   c  edge side 
               10   d  peripheral part 
               12  support glass 
               12   d  peripheral part 
               14  bubble 
               14   a  open bubble 
               14   b  close bubble 
               30  horn-type ultrasonic wave generator 
               31  liquid 
               32  tub (ultrasonic wave washing tub)