Substrate peeling device, method for peeling substrate, and method for fabricating flexible display device

Abstract

A method for fabricating a display device is provided. A laser having a power density is provided to a substrate coupling body. The substrate coupling body includes a first substrate and a second substrate coupled to the first substrate. The second substrate is separated from the first substrate. An optical property of the first substrate separated from the second substrate is measured. The power density of the laser is adjusted based on the optical property of the first substrate.

What is claimed is: 
     
         1 . A method for fabricating a display device, comprising:
 providing a laser having a power density to a substrate coupling body, wherein the substrate coupling body includes a first substrate and a second substrate coupled to the first substrate;   separating the second substrate from the first substrate;   measuring an optical property of the first substrate separated from the second substrate; and   adjusting the power density of the laser based on the optical property of the first substrate.   
     
     
         2 . The method for peeling a substrate of  claim 1 , wherein the optical property includes a light permeability of the first substrate, and
 the measuring the optical property of the first substrate comprises:   providing a test light to the first substrate so that the test light passes through the first substrate;   receiving the test light that has passed through the first substrate; and   calculating the light permeability of the first substrate from the received test light.   
     
     
         3 . The method for peeling a substrate of  claim 2 , wherein the adjusting the power density of the laser comprises decreasing the power density of the laser if the light permeability is less than a predetermined reference range. 
     
     
         4 . The method for peeling a substrate of  claim 2 , wherein the adjusting the power density of the laser comprises increasing the power density of the laser if the light permeability is greater than a predetermined reference range. 
     
     
         5 . The method for peeling a substrate of  claim 1 , wherein the optical property includes a light reflection ratio, and
 the measuring the optical property of the first substrate comprises:   providing a test light to the first substrate so that the test light is reflected from the first substrate;   receiving the light reflected from the first substrate; and   calculating the light reflection ratio using a first intensity of the test light provided to the first substrate and a second intensity of the test light reflected from the first substrate.   
     
     
         6 . The method for peeling a substrate of  claim 5 , wherein the adjusting the power density of the laser comprises decreasing the power density of the laser if the light reflection ratio is less than a predetermined reference range. 
     
     
         7 . The method for peeling a substrate of  claim 5 , wherein the adjusting the power density of the laser comprises increasing the power density of the laser if the light transmission ratio is greater than a predetermined reference range. 
     
     
         8 . The method for peeling a substrate of  claim 1 , wherein the optical property includes a retro reflection ratio, and
 the measuring the optical property of the first substrate comprises:   providing a test light to the first substrate so that the test light passes through the first substrate in a first direction;   reflecting the test light that has passed through the first substrate to the first substrate so that the test light reflected passes through the first substrate in a second direction opposite to the first direction;   receiving the test light that has passed through the first substrate in the second direction; and   calculating the retro reflection ratio from the a first intensity of the test light provided to the first substrate and a second intensity of the test light that has passed through the first substrate in the second direction.   
     
     
         9 . The method for peeling a substrate of  claim 8 , wherein the adjusting the power density of the laser comprises decreasing the power density of the laser if the retro reflection ratio is less than a predetermined reference range. 
     
     
         10 . The method for peeling a substrate of  claim 8 , wherein the adjusting the power density of the laser comprises increasing the power density of the laser if the retro reflection ratio is greater than a predetermined reference range. 
     
     
         11 . The method of  claim 1 , wherein the second substrate includes a flexible base material and a thin film transistor layer arranged on the flexible base material. 
     
     
         12 . A method for fabricating a display device comprising:
 providing a laser having a power density to a substrate coupling body, wherein the substrate coupling body includes a first substrate and a second substrate coupled to the first substrate;   measuring a reflection ratio of the substrate coupling body;   separating the first substrate and the second substrate from each other; and   adjusting the power density of the laser to based on the reflection ratio.   
     
     
         13 . The method for peeling a substrate of  claim 12 , wherein the laser is provided to a surface of the first substrate, and
 the measuring of the reflection ratio of the substrate coupling body comprises:   providing a light to the substrate coupling body so that the light is reflected from the substrate coupling body;   receiving the light reflected from the substrate coupling body; and   calculating the reflection ratio from the received test light   
     
     
         14 . The method for peeling a substrate of  claim 13 , wherein the power density of the laser is increased if the reflection ratio is less than a predetermined reference range. 
     
     
         15 . The method for peeling a substrate of  claim 13 , wherein the power density of the laser is decreased if the reflection ratio is greater than a predetermined reference range. 
     
     
         16 . The method of  claim 12 , wherein the second substrate includes a flexible base material and a thin film transistor layer arranged on the flexible base material. 
     
     
         17 . The method of  claim 16 , further comprising attaching a first protection film to the second substrate before the laser is provided to the substrate coupling body. 
     
     
         18 . The method for fabricating a flexible display device of  claim 17 , further comprising attaching a second protection film to the second substrate after the first substrate and the second substrate is separated from each other. 
     
     
         19 . The method for fabricating a flexible display device of  claim 18 , further comprising removing the first protection film from the second substrate after the second protection film is coupled to the second substrate. 
     
     
         20 . A substrate peeling device comprising:
 a laser irradiation unit configured to generate a laser having a power density and to irradiate the laser on a substrate coupling body, wherein the substrate coupling body includes a first substrate and a second substrate coupled to the first substrate; and   an optical property detection unit configured to measure an optical property of the first substrate separated from the second substrate using the laser,   wherein the power density of the laser is adjusted based on the optical property of the first substrate.   
     
     
         21 . The substrate peeling device of  claim 20 , wherein the optical property detection unit comprises:
 a light irradiation unit arranged over the first substrate and configured to irradiate a test light on the first substrate, wherein the test light passes through the first substrate;   a light receiving unit arranged under the first substrate and configured to receive the test light that has passed through the first substrate; and   an optical property calculation unit configured to calculate a light permeability of the first substrate from an intensity of the test light that the light irradiation unit provides to the first substrate and an intensity of the test light that the light receiving unit receives.   
     
     
         22 . The substrate peeling device of  claim 20 , wherein the optical property detection unit comprises:
 a light irradiation unit arranged over the first substrate and configured to irradiate a test light on the first substrate, wherein the test light is reflected from the first substrate;   a light receiving unit arranged over the first substrate and configured to receive the test light reflected from the first substrate; and   an optical property calculation unit configured to calculate a light reflection ratio of the first substrate from an intensity of the test light that the light irradiation unit provides to the first substrate and an intensity of the test light that the light receiving unit receives.   
     
     
         23 . The substrate peeling device of  claim 20 , wherein the optical property detection unit comprises:
 a light irradiation unit arranged over the first substrate and configured to irradiate a test light on the one surface, wherein the test light passes through the first substrate in a first direction;   a reflection plate arranged under the first substrate and configured to reflect the test light that has passed through the first substrate to the first substrate, wherein the test light reflected from the reflection plate passes through the first substrate in a second direction opposite to the first direction;   a light receiving unit arranged over the first substrate and configured to receive the test light that has passed through the first substrate in the second direction; and   an optical property calculation unit configured to calculate a retro reflection ratio of the first substrate from an intensity of the test light that the light irradiation unit provides to the first substrate and an intensity of the test light that the light receiving unit receives.   
     
     
         24 . The substrate peeling device of  claim 20 , further comprising a control unit configured to adjust the power density of the laser based on the optical property of the first substrate. 
     
     
         25 . A substrate peeling device comprising:
 a laser irradiation unit configured to irradiate a laser having a power density on a substrate coupling body, wherein the substrate coupling body includes a first substrate and a second substrate coupled to the first substrate; and   an optical property detection unit configured to measure a light reflection ratio of the substrate coupling body,   wherein the power density of the laser is adjusted based on the light reflection ratio of the substrate coupling body.   
     
     
         26 . The substrate peeling device of  claim 25 , further comprising a control unit configured to wherein the optical property detection unit comprises:
 a light irradiation unit arranged over the first substrate and configured to irradiate a test light on the first substrate;   a light receiving unit arranged over the first substrate and configured to receive the test light that is reflected from the substrate coupling body; and   an optical property calculation unit configured to calculate a light reflection ratio of the first substrate from an intensity of the test light that the light irradiation unit provides and an intensity of the test light that the light receiving unit receives.   
     
     
         27 . The substrate peeling device of  claim 25 , further comprising a control unit configured to adjust the power density of the laser based on the light reflection ratio of the substrate coupling body.