Method and apparatus for manufacturing flexible light emitting device

Abstract

According to a flexible light-emitting device production method of the present disclosure, after an intermediate region (30i) and a flexible substrate region (30d) of a plastic film (30) of a multilayer stack (100) are divided, the interface between the flexible substrate region (30d) and a glass base (10) is irradiated with lift-off light. The multilayer stack (100) is separated into the first portion (110) and the second portion (120) while the multilayer stack (100) is kept in contact with the stage (210). The first portion (110) includes a plurality of light-emitting devices (1000) which are in contact with the stage (210). The light-emitting devices (1000) include a plurality of functional layer regions (20) and the flexible substrate region (30d). The second portion (120) includes the glass base (10) and the intermediate region (30i). The step of irradiating with the lift-off light includes forming the lift-off light from a plurality of arranged light sources and temporally and spatially modulating a power of the plurality of lift-off light sources according to a shape of the flexible substrate region of the synthetic resin film such that the irradiation intensity of the lift-off light for at least part of the interface between the intermediate region (30i) and the glass base (10) is lower than the irradiation intensity of the lift-off light for the interface between the flexible substrate region (30d) and the glass base (10).

1 . An apparatus for producing a flexible light-emitting device, comprising:
 a stage for supporting a multilayer stack which has a first surface and a second surface, the multilayer stack including
 a glass base which defines the first surface, 
 a functional layer region including a TFT layer and a light-emitting device layer, 
 a synthetic resin film provided between the glass base and the functional layer region and bound to the glass base, the synthetic resin film including a flexible substrate region supporting the functional layer region and an intermediate region surrounding the flexible substrate region, and 
 a protection sheet which covers the functional layer region and which defines the second surface, 
 the intermediate region and the flexible substrate region of the synthetic resin film being divided from each other; and 
   a lift-off light irradiation unit for irradiating with lift-off light an interface between the synthetic resin film and the glass base in the multilayer stack supported by the stage,   wherein the lift-off light irradiation unit includes a plurality of arranged light sources for forming the lift-off light, and the lift-off light irradiation unit configured to:   modulating temporally and spatially a power of the plurality of light sources according to a shape of the flexible substrate region of the synthetic resin film such that an irradiation intensity of the lift-off light for at least part of an interface between the intermediate region of the synthetic resin film and the glass base is lower than a threshold level Th of the irradiation intensity which is necessary for delamination;   irradiate the at least part of the interface between the intermediate region of the synthetic resin film and the glass base with the lift-off light; and   irradiate the interface between the flexible substrate region of the synthetic resin film and the glass base with the lift-off light whose irradiation intensity is higher than threshold level Th.   
     
     
         2 . The apparatus of  claim 1 , wherein each of the plurality of arranged light sources is an incoherent light source. 
     
     
         3 . The apparatus of  claim 1 , wherein the light-emitting device layer includes a plurality of arrayed micro LEDs, and
 each of the plurality of light sources is a semiconductor laser device.   
     
     
         4 . The apparatus of  claim 1 , wherein
 the plurality of light sources are a plurality of light emitting diode devices, and   the lift-off light irradiation unit includes a driving circuit for modulating a driving current flowing through each of the plurality of light emitting diode devices, thereby temporally and/or spatially modulating the irradiation intensity of the lift-off light.   
     
     
         5 . The apparatus of  claim 4 , wherein
 the plurality of light emitting diode devices are arranged in a single row or a plurality of rows.   
     
     
         6 . The apparatus of  claim 5 , wherein
 an arrangement pitch of the plurality of light emitting diode devices is in a range of not less than 3 mm and not more than 10 mm.   
     
     
         7 . The apparatus of  claim 1 , further comprising an actuator for increasing a distance from the stage to the glass base while the stage is kept in contact with the second surface of the multilayer stack, thereby separating the multilayer stack into a first portion and a second portion,
 wherein the first portion of the multilayer stack includes a light-emitting device which is in contact with the stage, the light-emitting device including the functional layer region and the flexible substrate region of the synthetic resin film, and   the second portion of the multilayer stack includes the glass base and the intermediate region of the synthetic resin film.   
     
     
         8 . A method for producing a flexible light-emitting device, comprising:
 providing a multilayer stack which has a first surface and a second surface, the multilayer stack including
 a glass base which defines the first surface, 
 a functional layer region including a TFT layer and a light-emitting device layer, 
 a synthetic resin film provided between the glass base and the functional layer region and bound to the glass base, the synthetic resin film including a flexible substrate region supporting the functional layer region and an intermediate region surrounding the flexible substrate region, and 
 a protection sheet which covers the functional layer region and which defines the second surface; 
   dividing the intermediate region and the flexible substrate region of the synthetic resin film from each other;   irradiating an interface between the synthetic resin film and the glass base with lift-off light; and   separating the multilayer stack into a first portion and a second portion by increasing a distance from a stage to the glass base while the second surface of the multilayer stack is kept in contact with the stage,   wherein the first portion of the multilayer stack includes a light-emitting device which is in contact with the stage, the light-emitting device including the functional layer region and the flexible substrate region of the synthetic resin film,   the second portion of the multilayer stack includes the glass base and the intermediate region of the synthetic resin film, and   irradiating the interface between the synthetic resin film and the glass base with the lift-off light includes;   forming the lift-off light from a plurality of arranged light sources and temporally and spatially modulating a power of the plurality of light sources according to a shape of the flexible substrate region of the synthetic resin film;   reducing an irradiation intensity of the lift-off light for at least part of an interface between the intermediate region of the synthetic resin film and the glass base below a threshold level Th of the irradiation intensity which is necessary for delamination;   irradiating the at least part of the interface between the intermediate region of the synthetic resin film and the glass base with the lift-off light, and   irradiating the interface between the flexible substrate region of the synthetic resin film and the glass base with the lift-off light whose irradiation intensity is higher than threshold level Th.   
     
     
         9 . The method of  claim 8 , wherein the lift-off light is incoherent light. 
     
     
         10 . The method of  claim 8 , wherein
 the light-emitting device layer includes a plurality of arrayed micro LEDs, and   the lift-off light is laser light.   
     
     
         11 . The method of  claim 8 , wherein a shape of the flexible substrate region of the synthetic resin film has a cutout, a protrusion, and/or a curved contour when viewed in a direction perpendicular to the first surface. 
     
     
         12 . The method of  claim 8 , wherein
 a number of the flexible substrate region of the synthetic resin film is plural, and   a number of the light-emitting device included in the first portion of the multilayer stack is plural.   
     
     
         13 . The method of  claim 8 , wherein
 the plurality of light sources are a plurality of light emitting diode devices, and   irradiating the interface between the synthetic resin film and the glass base with the lift-off light includes modulating a driving current flowing through each of the plurality of light emitting diode devices, thereby temporally and/or spatially modulating the irradiation intensity of the lift-off light.   
     
     
         14 . The method of  claim 13 , wherein
 the plurality of light emitting diode devices are arranged in a single row or a plurality of rows.   
     
     
         15 . The method of  claim 14 , wherein
 an arrangement pitch of the plurality of light emitting diode devices is in a range of not less than 3 mm and not more than 10 mm.   
     
     
         16 . The method of  claim 8 , wherein
 the lift-off light is a line beam extending in a first direction which is parallel to a perimeter of the glass base, and   irradiating the interface between the synthetic resin film and the glass base with the lift-off light includes moving an irradiation region on the interface which is to be irradiated with the lift-off light in a second direction which is transverse to the first direction.   
     
     
         17 . The method of  claim 8 , wherein
 the lift-off light is plane-like light extending in a first direction and a second direction, the first direction being parallel to a perimeter of the glass base, the second direction being transverse to the first direction, and
 irradiating the interface between the synthetic resin film and the glass base with the lift-off light includes moving or not-moving irradiation region on the interface which is to be irradiated with the lift-off light. 
   
     
     
         18 . The method of  claim 9 , wherein
 the at least part of the interface between the intermediate region of the synthetic resin film and the glass base includes a plurality of parallel stripe regions extending in a first direction which is parallel to a perimeter of the glass base, and   any of the plurality of parallel stripe regions includes a large-width portion and/or a narrow-width portion.   
     
     
         19 . The method of  claim 9 , wherein
 the at least part of the interface between the intermediate region of the synthetic resin film and the glass base includes a plurality of parallel stripe regions extending in a second direction which is transverse to a first direction which is parallel to a perimeter of the glass base, and   any of the plurality of parallel stripe regions includes a large-width portion and/or a narrow-width portion.   
     
     
         20 . The method of  claim 8 , wherein the at least part of
 the interface between the intermediate region of the synthetic resin film and the glass base has a width which is not less than 50% of a width of the intermediate region.