TWI465791B - Method and system for repairing flat panel module - Google Patents

Description

Patching module repair method and system

The invention is a repairing technology, in particular, a repairing panel repairing method and system for a liquid crystal grouping process (cell) segment in a display module process.

The liquid crystal display is a non-active light-emitting component, and the color display must provide a light source through the backlight module, and the driving circuit and the liquid crystal control form a gray scale brightness display, and the red (R), green (G) and blue of the filter light are transmitted through the filter. The color (B) color layer gives each pixel a specific color, and the pixels of different colors form a color picture. If there is a flaw in the panel, the pixel in the display will not display the desired color correctly, and a bright spot or a dark dot will be formed. Especially the bright spot is particularly obvious for the display user, so the number of bright spots is also one of the panel rating elements. As shown in FIG. 1 , the figure is a schematic diagram of a liquid crystal display module. A polarizing plate 11 and 12 are attached to upper and lower sides of the liquid crystal display module 10 . In the conventional technology, the inner layer or the adhesive layer of the polarizing plates 11 and 12 is used. The foreign matter will cause serious light leakage during the power-on test, so that the liquid crystal display module and the backlight module are combined, and the formed liquid crystal display generates a defect of the bright spot 13 . Excimer laser processing is often used when repairing the bright spots caused by the polarizing plates 11 and 12. However, such a processing method has a large heat-affected area, resulting in damage to the area around the display and the surface of the polarizing plate.

In the conventional repairing technique, for example, the method for repairing a liquid crystal display panel proposed by the Republic of China Publication No. 200827819 uses a first nanosecond laser to cause a gap crack in the filter, and a second femtosecond laser ( 450 nm, 10 MHz or more) or Diode Laser, through the linear absorption, the filter of the existing gap is changed in physical properties to reduce the light transmittance of the bright spot. In addition, as disclosed in the Republic of China Publication No. 200829977 and 200887821, a method and a device for repairing a liquid crystal display panel are disclosed, which use a 450 nm femtosecond laser to repair using a linear absorption interval of RGB, which is processed by a crystal face of a liquid crystal display. Repairing from the color filter surface can easily damage the polarizing film.

In addition, as disclosed in WO 2008-156286, a repair method is disclosed in which a gap is formed between the photoresist material and the glass by laser irradiation, and the surrounding black matrix is melted by laser scanning. In the gap, the photoresist region having a bright spot is blackened. (not directly blackening the photoresist). A repairing method is also disclosed in U.S. Patent No. 7,502,094, which is irradiated by a laser (Nd:YAG laser 380-740 nm, <55 Hz) in a reticle to cause the filter to face the substrate surface. Blackening (so that the light generated by the light source cannot pass through the filter), due to the diffusion zone generated during the irradiation process, it is necessary to process the three sets of different sizes of masks to repair the bright spots. In addition, a method and system for repairing a liquid crystal display is disclosed in US Pat. No. 7,636,148, which discloses three repair methods. The first one is to apply a repair film on the glass substrate under the panel. The repair film is processed by a laser (YAG, excimer, diode laser) at a position where there is a bright spot. The second is processed in black matrix. A third type of pattern spacer process covers the melted support onto a colored photoresist with bright spots. U.S. Patent No. 7,126,232 is also a repair mechanism for transferring a repair film to a defect location.

In addition, as disclosed in US Pat. No. 5,926,246 or US Pat. No. 2006050623, a repairing method is also disclosed which utilizes an alignment film processed by a laser in a liquid crystal panel to detect a bright spot region by using a rotating direction of the polarizing film. , laser processing alignment film. The Republic of China new patent M381804 provides a repair device for a display containing a filter, comprising at least one laser source, at least two mirror groups, at least two lenses and at least one lens group control unit, which are selectively outputtable The laser light of different wavelengths is used to blacken the color points of different colors on the filter to complete the bright spot repair.

The invention provides a method and a system for repairing a flat display module, which utilizes a femtosecond laser to focus on a polarizing plate corresponding to a flaw, and performs a modification process on the polarizing plate, because the femtosecond laser can be processed. The polarizer produces multiphoton nonlinear absorption; it has the characteristics of small heat affected zone and controlled processing depth, so it can directly repair the display module with defects without damaging the structure of other areas in the display module.

The invention provides a method and a system for repairing a flat display module, which is configured to enable femtosecond laser light to pass through a surface layer above a polarizing plate, and focus on a position corresponding to a bright spot on the polarizing plate, so that the inner layer of the polarizing plate is modified and blackened. The bright spots on the original formed panel become dark spots, and will not cause damage to other areas, improving the quality and grade of the display products.

The invention provides a method and a system for repairing a flat display module, which can repair a display module with a bright spot defect during the liquid crystal group manufacturing process in the production process of the liquid crystal display module to improve the liquid crystal The yield and productivity of the display process.

In one embodiment, the present invention provides a method for repairing a flat display module, comprising the steps of: providing a flat display module having a polarizing plate attached to a surface thereof, the flat display module having at least one bright point; A femtosecond laser is provided to focus on the polarizing plate corresponding to the bright spot, so that the polarizing plate corresponding to the bright spot generates nonlinear multiphoton absorption to form a modified region, thereby converting the bright spot into a dark spot.

In another embodiment, the present invention provides a flat display module repairing system, comprising: a mobile platform for carrying a flat display module having a bright spot defect; and a femtosecond laser source The system provides a femtosecond laser to focus on the planar display module corresponding to the corresponding bright spot, so that the planar display module generates nonlinear multiphoton absorption and is modified, thereby converting the bright spot into a dark spot.

In order to enable the reviewing committee to have a further understanding and understanding of the features, objects and functions of the present invention, the related detailed structure of the device of the present invention and the concept of the design are explained below so that the reviewing committee can understand the present invention. The detailed description is as follows: Please refer to FIG. 2, which is a schematic flowchart of an embodiment of a method for repairing a flat display module of the present invention. The repair method 2 first provides a flat display module in step 20. As shown in FIG. 3, the figure is a schematic cross-sectional view of a planar display module. In this embodiment, the flat display module 3 is a liquid crystal flat display module, but not limited thereto, as long as the display that needs to be attached with the polarizing plate can be repaired by the method of the embodiment. The display module in this embodiment is a liquid crystal display module having a polarizing plate formed in a liquid crystal group process segment.

The flat display module 3 has a liquid crystal layer unit 30 having an upper substrate 31 and a lower substrate 32, which may be made of glass or plastic. A liquid crystal 301 is filled between the upper substrate 31 and the lower substrate 32, and a filter layer 34 is provided between the upper substrate 31 and the liquid crystal 301. In this embodiment, the filter layer 34 is a color filter layer. The surface 310 of the upper substrate 31 is the display surface of the flat display module 3, and the bottom surface 320 of the lower substrate 32 is the light receiving surface of the flat display module 3, which can receive the light field emitted by the backlight. . The lower substrate 32 has a thin film transistor layer 300 having a liquid crystal 301 having a spacer 302 therein. In the embodiment, the surface 310 of the substrate 31 and the bottom surface 320 of the lower substrate 32 of the flat display module 3 are respectively provided with polarizing plates 4 and 5. The flat display module 3 has a flaw 94, and the crucible 94 in this embodiment is a defect of a bright spot. The so-called bright spot defects may be caused by foreign matter in the inner layer or the adhesive layer of the polarizing plate 4 or 6, which may cause serious light leakage during the power-on test, or may be caused by the filter layer 34, the liquid crystal 30, or a circuit defect. The 瑕疵94 in the figure refers to a foreign matter which is caused by a foreign matter in the inner layer or the adhesive layer of the polarizing plate 4 or 5, which causes a serious light leakage during the power-on test.

Then proceeding to step 21, providing a femtosecond laser focusing illumination on the polarizing plate corresponding to the bright spot, causing nonlinear multiphoton absorption in the polarizing plate corresponding to the bright spot, and modifying the blackening, thereby converting the bright spot into a dark spot . As shown in FIG. 4, the femtosecond laser 90 is focused on the polarizing plate 4 corresponding to the bright spot, so that the inside of the polarizing plate 4 is modified to form a blackened region 91. The modification in step 21 can make the physical change of the region on the polarizing plate 4 corresponding to the bright spot due to multiphoton absorption by the femtosecond laser beam, thereby forming blackening and no other damage. . It should be noted that the present invention can adjust the state of the femtosecond laser by adjusting the wavelength of the femtosecond laser, the pulse frequency, the laser power, and the polarization direction, thereby making the area corresponding to the bright spot inside the polarizing plate Non-linear multiphoton absorption produces a physical reaction that causes blackening of this area and no damage to other areas. Wherein, the wavelength range of the femtosecond laser is 200~1100 nm; and the laser pulse frequency of the femtosecond laser is between 1 Hz and 2 MHz; the projection power density of the femtosecond laser projected onto the polarizing plate is greater than 10 ⁸ W/cm ² . The pulse width of the femtosecond laser is less than or equal to 500 femtoseconds.

Please refer to FIG. 5A, which is a schematic diagram of the flat display module repairing system of the present invention. The flat display module repair system 6 includes a mobile platform 60 and a femtosecond laser source 61. The mobile platform 60 has a platform 600 and a driving unit 601 that drives the platform 600 to generate a three-dimensional linear displacement motion. In this embodiment, the driving unit 601 is composed of a component such as a motor and a screw or a linear motor, but is not limited thereto. The driving unit 601 drives the platform 600 to generate a displacement movement in the X and Y directions, so that the platform 600 can perform a position adjustment action on a horizontal plane; in addition, the driving unit 601 drives the platform 600 to generate a displacement movement in the Z-axis direction to adjust the focusing unit. 64 The distance from the platform 600. A planar display module 3 is disposed on the mobile platform 60, which has a defect of a bright spot. The structure of the planar display module 3 is as shown in FIG. 3, and details are not described herein.

The mobile platform 60 is further coupled to a control unit 62, which can be a computer or a single chip with computing processing capability combined with a memory. The position of the bright spot is input by the input interface provided by the control unit 62, so that the control unit 62 records the position about the bright spot. The control unit 62 can generate a control signal to move the mobile platform 60 to correspond to the femtosecond laser 90, and focus the femtosecond laser 90 on the polarizing plate 4 of the flat display module 3. In the present embodiment, the polarizing plate 4 refers to the polarizing plate 4 on the upper substrate 31. However, the polarizing plate 5 attached to the bottom surface of the lower substrate 32 may be implemented without limitation. The control unit 62 generates a control signal to the driving unit 601. After receiving the driving signal, the driving unit 601 drives the platform 600 to generate a displacement motion corresponding to the driving signal.

The femtosecond laser source 61 is disposed on one side of the moving platform 60. In this embodiment, it is an upper portion, which can generate a femtosecond laser 90. The femtosecond laser source 61 is further coupled to an adjustment unit 63. In this embodiment, the adjusting unit 63 further includes a laser wavelength adjusting device 630, a laser frequency adjusting device 631, and a laser energy and polarization adjusting device 632 to adjust the wavelength, pulse frequency, and thunder of the femtosecond laser. Features such as energy and polar angle. The laser wavelength adjusting device 630 can adjust the wavelength range of the femtosecond laser to be 200 to 1100 nm. The laser frequency adjusting device 631 adjusts the range of the femtosecond laser frequency between 1 Hz and 2 MHz. In addition, the laser energy and polarization adjusting device 632 can adjust the energy of the femtosecond laser. In the embodiment, the laser energy and the polarization adjusting device 632 adjust the projection power of the femtosecond laser to be greater than 10 ⁸ W/ Cm ² .

In addition, please refer to FIG. 6 , which is a schematic diagram of a light beam passing through a polarizing plate. Since the spirit of the present invention is to provide a femtosecond laser focusing illumination on the polarizing plate, in FIG. 6, if the polarization direction of the femtosecond laser is not controlled, as shown by the femtosecond laser 90 in FIG. Then, a part of the femtosecond laser penetrates the polarizing plate 4 and reaches other areas in the flat display module, which may cause damage to the internal structure of the flat display module. Therefore, according to the characteristics that the polarizing plate has different light absorption rates for different polarization directions, the laser energy and polarization adjusting device 632 can control the repairing effect by adjusting the polarization direction of the laser, and the laser polarizing direction and the polarizing plate are required. At an angle, the angle can be greater than zero degrees. The better effect is as shown in FIG. 6B, which can make the polarization of the femtosecond laser 90 perpendicular to the polarization angle of the polarizing plate 4, so that the laser energy is easily absorbed by the polarizing plate. Blackening occurs.

Returning to FIG. 5A, in order to increase the focusing effect of the femtosecond laser 90, a focusing objective 64 is disposed on the optical path of the femtosecond laser 90 projected onto the planar display module 3. The focusing objective 64 is composed of at least one focusing lens or mirror, the composition of which can be combined using lenses of the prior art. The focal length of the femtosecond laser 90 can also be achieved by varying the height or focal length of the focusing lens 64. In addition, a mirror 65 may be disposed on the optical path of the femtosecond laser 90 to guide the femtosecond laser 90 to the flat display module 3. In the present embodiment, the focusing objective 64 has a numerical aperture (NA) value of 0.5 or more. By focusing the objective lens 64 with a high numerical aperture value, the energy at the focus focus can be concentrated, and the defocus angle is large, the laser dose can be effectively reduced, and the area outside the focus is prevented from being subjected to laser processing.

As shown in Fig. 7A, the figure is a schematic view of a focused spot produced by focusing an objective lens with a high NA value. Since the high NA objective lens has a small spot size 92, it can produce a good modification effect on the polarizing plate, but it is not suitable for a large-area processing process. Therefore, in another embodiment, as shown in FIG. 5B, before the focusing objective 64, a shaping element 66 may be further disposed to pass the femtosecond laser through the shaping element 66 before entering the focusing objective 64. To adjust the shape of the focused spot. In this embodiment, the shaping element 66 is a slit structure, but is not limited thereto. The shape of the slit may be a polygon, and this embodiment is a rectangle. When the laser light is diffracted by the shaping element 66 and then focused by the focusing objective 64, its spot will be laterally elongated to form a focused spot 93 as shown in FIG. 7B, but the energy distribution of the beam direction is unchanged. This method can compensate for the disadvantages of low efficiency of high NA objective processing. Due to the low thermal processing effect of the femtosecond laser itself, the optical path is integrated with the spot for the focus to make efficient shaping, which can be quickly modified inside the polarizing film to repair defects. By combining the objective lens and the shaping element, it is possible to quickly produce a thinner modified region inside the polarizing plate having a thickness of 30 to 50 μm.

As shown in FIG. 5A, the flat display module repairing system 6 repairs the flat display module 3 having bright spots according to the steps shown in FIG. The control unit 62 initially sets the position for each bright spot or to be repaired. The control unit 62 controls the drive unit 601 according to the set position to cause the platform 600 to generate a corresponding displacement motion. Since the femtosecond laser source 61 is stationary, the bright spot can be moved to the position corresponding to the femtosecond laser 90 by the displacement movement of the platform 600, so that the femtosecond laser 90 is focused on the internal display module 3 The polarizing plate 4 at the position of the bright spot should be made to generate a modified region 91 by nonlinear multiphoton absorption corresponding to the light-transmitting substrate corresponding to the bright spot, and the laser light repairing position can also be adjusted by the optical path and the position of the focusing module 64. The change is achieved, and the position of the flat display module to be repaired is fixed (flying light path); or it is achieved by displacing the two. When the polarizing plate 4 corresponding to the bright spot is blackened, the phenomenon of scattering or reflection caused by the light emitted from the bright spot to the structure in the modified region makes the light unable to penetrate the polarizing plate. By modifying the polarizing plate by the repairing system 6, the local blackening repair highlights can be achieved under the condition that the surface of the polarizing plate is free from damage and side leakage, thereby improving the level of the display.

In addition, as shown in FIG. 3, in the foregoing embodiment, the polarizing plate 4 of the surface 310 of the upper substrate 31 in the flat display module 3 is repaired, but the above substrate is not limited. That is, if the light leakage defect occurs on the polarizing plate 5 on the bottom surface of the lower substrate 32, the polarizing plate 5 can also be repaired. Moreover, in another embodiment, the planar display 8 containing the backlight 7 as shown in FIG. 8 can also be repaired using the method and system of the present invention. Although the foregoing embodiment is to form a blackened modified region in the polarizing plate, according to the spirit of the present invention, the femtosecond laser can be formed on the surface of the polarizing plate as long as the focus position of the femtosecond laser is adjusted. The quality area can also achieve the effect of repairing.

However, the above is only an embodiment of the present invention, and the scope of the present invention is not limited thereto. It is to be understood that the scope of the present invention is not limited by the spirit and scope of the present invention, and should be considered as a further embodiment of the present invention.

10. . . Liquid crystal display module

11,12. . . Polarizer

13. . . defect

2. . . Flat display module repair method

20~21. . . step

3. . . Flat display module

30. . . Liquid crystal layer unit

300. . . Thin film transistor layer

301. . . liquid crystal

302. . . Support

31. . . Upper substrate

310. . . surface

32. . . Lower substrate

320. . . Bottom

34. . . Filter layer

4, 5. . . Polarizer

6. . . Flat display module repair system

60. . . mobile platform

61. . . Femtosecond laser source

600. . . platform

601. . . Drive unit

62. . . control unit

63. . . Adjustment unit

630. . . Laser wavelength adjustment device

631. . . Laser frequency adjustment device

632. . . Laser energy and polarization adjustment device

64. . . Focus unit

65. . . Reflector

66. . . Shaping element

90. . . Femtosecond laser

91. . . Blackened area

92, 93. . . Focus spot

94. . . defect

Figure 1 is a schematic diagram of a liquid crystal display module.

FIG. 2 is a schematic flow chart of an embodiment of a method for repairing a flat display module according to the present invention.

Figure 3 is a schematic cross-sectional view of a flat display module.

Figure 4 is a schematic view showing the formation of a black modified region in the polarizing plate of the flat display module.

FIG. 5A is a schematic diagram of a flat display module repairing system of the present invention.

FIG. 5B is a schematic diagram of another embodiment of the flat display module repairing system of the present invention.

Figure 6A and Figure 6B are schematic diagrams of a femtosecond laser passing through a polarizing plate.

Figure 7A is a schematic view of a focused spot produced by a high NA value focusing objective lens of the present invention.

Figure 7B is a schematic view of the focused spot generated by the high NA value focusing objective lens and the shaping element of the present invention.

Figure 8 shows a schematic diagram of a flat panel display with a backlight.

2. . . Flat display module repair method

20~21. . . step

Claims (26)

A flat display module repairing method comprising the steps of: providing a flat display module having a polarizing plate attached to a surface thereof, the flat display module having at least one bright point; and providing a femtosecond laser focusing illumination On the polarizing plate corresponding to the bright spot, by adjusting the wavelength, pulse frequency, laser power and polarization direction of the femtosecond laser, a nonlinear multiphoton absorption is generated for the polarizing plate corresponding to the bright spot to form a modified a region, which in turn converts the bright spot into a dark spot; wherein the polarization direction of the femtosecond laser is perpendicular to the polarization angle of the polarizing plate. For example, the flat display module repairing method of claim 1 is characterized in that the wavelength range of the femtosecond laser is 200~1100 nm. For example, the flat display module repairing method of claim 1 is characterized in that the laser pulse frequency of the femtosecond laser is between 1 Hz and 2 MHz. The method for repairing a flat display module according to claim 1, wherein the projection power density of the femtosecond laser projected onto the polarizing plate is greater than 10 ⁸ W/cm ² . The method for repairing a flat display module according to claim 1, further comprising the step of projecting the femtosecond laser through a mirror and a focusing objective onto the polarizing plate corresponding to the bright spot. The method for repairing a flat display module according to claim 5, wherein the numerical aperture value of the focusing objective is greater than or equal to 0.5. The method for repairing a flat display module according to claim 5, further comprising the step of the femtosecond laser entering the focusing objective The femtosecond laser passes through a step of shaping the component. The flat display module repairing method of claim 7, wherein the shaping element is an element having a slit structure. For example, the flat display module repairing method of claim 1 further includes one step of modulating the polarization direction of the femtosecond laser. The flat display module repairing method of claim 9, wherein the polarization direction of the femtosecond laser is at an angle to a polarization direction of the polarizing plate, and the angle is greater than zero degrees. The flat display module repairing method of claim 1, wherein the flat display module is a liquid crystal module, which is combined with a backlight module to form a flat display, and the liquid crystal module has a display surface. And a light receiving surface corresponding to one of the light emitting surfaces of the backlight module, the polarizing plate being attached to the display surface. The flat display module repairing method of claim 1, wherein the flat display module is a liquid crystal module, which is combined with a backlight module to form a flat display, and the liquid crystal module has a display surface. And a light receiving surface corresponding to a light emitting surface of the backlight module, wherein the polarizing plate is attached to the light receiving surface. A flat display module repairing system includes: a mobile platform for carrying a flat display module having a bright spot defect, the flat display module surface is attached with a polarizing plate; and a femtosecond mine a source, which provides a femtosecond laser to focus on the polarizing plate corresponding to the bright spot, by adjusting the wavelength, pulse frequency, laser power and polarization direction of the femtosecond laser The polarizing plate that should be brightened produces non-linear multiphoton absorption and is modified, thereby converting the bright spot into a dark spot; wherein the polarization direction of the femtosecond laser is perpendicular to the polarization angle of the polarizing plate. For example, in the flat display module repairing system of claim 13, wherein the femtosecond laser source further has an adjusting unit for adjusting the wavelength, pulse frequency, laser power and polarization direction of the femtosecond laser. For example, the flat display module repairing system of claim 14 wherein the femtosecond laser has a wavelength range of 200 to 1100 nm. For example, in the flat display module repairing system of claim 14, wherein the laser pulse frequency of the femtosecond laser is between 1 Hz and 2 MHz. For example, in the flat display module repairing system of claim 14, wherein the projection power density of the femtosecond laser projected onto the flat display module is greater than 10 ⁸ W/cm ² . The flat display module repairing system of claim 13, wherein a mirror and at least one focusing objective are further disposed on the optical path of the femtosecond laser to modulate the femtosecond laser. For example, the flat display module repairing system of claim 18, wherein the numerical aperture value of the focusing objective lens is greater than or equal to 0.5. The flat display module repairing system of claim 13, wherein the femtosecond laser passes through a shaping element before entering the focusing objective. The flat display module repairing system of claim 20, wherein the shaping element is an element having a slit structure. Such as the flat display module repairing system of claim 13 of the patent scope, The mobile platform includes a platform and a driving unit that provides driving of the platform to generate a three-dimensional linear displacement motion. The flat display module repairing system of claim 13 further includes a control unit, wherein the control unit records the position of the bright spot to generate a control signal to move the mobile platform to make the bright spot correspond to the femtosecond. The laser causes the femtosecond laser to be focused on the planar display module. The flat display module repairing system of claim 13 , wherein the flat display module is a liquid crystal module, which is combined with a backlight module to form a flat display, the liquid crystal module has a display surface And a light receiving surface corresponding to one of the light emitting surfaces of the backlight module, the polarizing plate being attached to the display surface. The flat display module repairing system of claim 13 , wherein the flat display module is a liquid crystal module, which is combined with a backlight module to form a flat display, the liquid crystal module has a display surface And a light receiving surface corresponding to a light emitting surface of the backlight module, wherein the polarizing plate is attached to the light receiving surface. The planar display module repairing system of claim 13, wherein the femtosecond laser has a polarization direction, which is at an angle to a polarization direction of the polarizing plate, and the angle is greater than zero degrees.