Pressure-sensing stages for lamination systems

• US 9,868,273 B2
• Filed: 09/20/2013
• Issued: 01/16/2018
• Est. Priority Date: 09/20/2013
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Sung, Kuo-Hua, Kim, Yong-Soo
• Primary Examiner(s): Koch, George
• Application Number:
  US14/897,074
• Publication Number:
  US 20160136937A1
• Time in Patent Office: 1,579 Days
• Field of Search: 156 64, 156358, 156367
• CPC Class Codes: B30B 15/22 controlling the degree of pressure applied by the ram during the pressing stroke
• CPC Class Codes: B32B 2457/202 LCD, i.e. liquid crystal displays
• CPC Class Codes: B32B 37/1009 using vacuum and fluid pressure
• CPC Class Codes: B32B 41/00 Arrangements for controlling or monitoring lamination processes; Safety arrangements

Abstract

A lamination system (110) may be provided for attaching together display layers (45,46) for an electronic device display. The system may include one or more pressure-sensing lamination stages (124, 126) for temporarily mounting the display layers during lamination operations. A pressure-sensing lamination stage (124) may include one or more pressure sensors (130) configured to sense pressures that are applied to the display layers during lamination operations. The pressure-sensing lamination stages may include a fixed mounting stage (126) and a movable mounting stage (124). The movable mounting stage may be moved so that a first set of display layers is pressed against a second set of display layers to attach the first and second sets of display layers. The pressure with which the first set of display layers (45;46) is pressed against the second set of display layers may be adjusted based on pressure data gathered using the pressure sensors (130).

Claims

1. A lamination system for laminating a first structure to a second structure, the system comprising:

a mounting stage for mounting the first structure;

a movable mounting stage for mounting the second structure, wherein the movable mounting stage includes at least one pressure sensor, the at least one pressure sensor monitoring an uniformity of pressure with which the first structure and the second structure are pressed together during lamination operations;

a positioner configured to move the movable mounting stage at least laterally or vertically relative to the mounting stage so that the first structure and the second structure come in contact;

actuators between the positioner and the movable mounting stage; and

computing equipment coupled to the movable mounting stage and the at least one pressure sensor, wherein the computing equipment is configured to gather pressure data associated with pressures on the second structure using the at least one pressure sensor,

wherein the computing equipment is configured to receive pressure signals from the at least one pressure sensor during lamination operations, compare the received pressure signals to target pressures, and responsive to the first structure and the second structure coming into contact operate the actuators based on the received pressure signals so that a uniform pressure is applied across the first structure and the second structure, and

wherein operation of the actuators cause the movable mounting stage to move laterally or vertically, and rotate in a x-y plane or out of the x-y plane in order to adjust the position and orientation of the movable mounting stage.

2. The lamination system defined in claim 1 wherein the at least one pressure sensor has an outer surface that is formed in a common plane with a surface of the movable mounting stage.

3. The lamination system defined in claim 1 wherein the at least one pressure sensor is embedded within the movable mounting stage.

4. The lamination system defined in claim 1 wherein the actuators are hydraulic actuators.

5. The lamination system defined in claim 1 wherein the at least one pressure sensor comprises at least first and second pressure sensors mounted at discrete locations on the movable mounting stage.

6. The lamination system defined in claim 1 wherein the at least one pressure sensor comprises pressure sensing layer of the movable mounting stage.

7. The lamination system defined in claim 1 wherein the mounting stage for mounting the first structure comprises a fixed mounting stage for mounting a display assembly for an electronic device display.

8. The lamination system defined in claim 7 wherein the movable mounting stage for mounting the second structure comprises a movable mounting stage for mounting a liquid crystal display cell to be laminated to the display assembly.

9. The lamination system defined in claim 8 wherein the fixed mounting stage comprises an electrostatic chuck that secures the display assembly in a fixed position.

10. The lamination system defined in claim 9, further comprising a vacuum chamber, wherein the fixed mounting stage and the movable mounting stage are mounted within the vacuum chamber.

11. A method of laminating a first rigid structure to a second rigid structure using hard-to-hard lamination equipment having a first stage and a second stage, wherein the second stage is a pressure-sensing stage having a plurality of pressure sensors, the method comprising:

temporarily attaching the first rigid structure to the first stage;

temporarily attaching the second rigid structure to the pressure-sensing stage;

operating a positioner to move the second stage relative to the first stage at least laterally or vertically so that the first rigid structure and the second rigid structure come in contact;

gathering pressure data using the plurality of pressure sensors; and

operating actuators between the positioner and the second stage based on the gathered pressure data to laminate the first rigid structure to the second rigid structure,

wherein the gathering pressure data comprises monitoring an uniformity of pressure with which the first rigid structure and the second rigid structure are pressed together during the laminating the first rigid structure to the second rigid structure, and

wherein the operating of actuators comprises moving the pressure-sensing stage laterally or vertically, and rotating the pressure-sensing stage in a x-y plane or out of the x-y plane in order to adjust a position and orientation of the pressure-sensing stage for applying an uniform pressure to the first rigid structure and the second rigid structure.

12. The method defined in claim 11 wherein gathering the pressure data using the plurality of pressure sensors comprises gathering absolute pressure data corresponding to a pressure with which the first rigid structure is pressed against the second rigid structure.

13. The method defined in claim 11 wherein gathering the pressure data using the plurality of pressure sensors comprises gathering relative pressure data corresponding to a uniformity of pressure with which the first rigid structure is pressed against the second rigid structure.

14. The method defined in claim 11 wherein operating the actuators comprises comparing the gathered pressure data to target pressure data.

15. The method defined in claim 14 wherein operating the actuators further comprises modifying the position of the pressure-sensing stage based on the comparison of the gathered pressure data to the target pressure data.

16. A method of using a laminating system to attach a liquid crystal display cell to an assembly that includes a glass layer, a touch-sensor substrate attached to the glass layer, and a sheet of optically clear adhesive on the touch-sensor substrate, the method comprising:

securing the assembly in a fixed position;

securing the liquid crystal display cell to a movable pressure-sensing mounting stage;

operating a positioner to move the movable pressure-sensing mounting stage at least laterally or vertically so that the liquid crystal display cell and the assembly come in contact;

gathering pressure data using the movable pressure-sensing mounting stage; and

operating actuators based on the gathered pressure data to press the liquid crystal display cell against the sheet of optically clear adhesive material,

wherein the gathering pressure data comprises monitoring an uniformity of pressure with which the assembly and the liquid crystal display cell are pressed together during the pressing the liquid crystal display cell, and

wherein operating the actuators comprises moving the movable pressure-sensing mounting stage laterally or vertically, and rotating the movable pressure-sensing mounting stage in a x-y plane or out of the x-y plane in order to adjust a position and orientation of the movable pressure-sensing mounting stage for applying an uniform pressure across the assembly and the liquid crystal display cell.

17. The method defined in claim 16 wherein gathering the pressure data using the movable pressure-sensing mounting stage comprises:

generating pressure signals using pressure sensors on the movable pressure-sensing mounting stage; and

generating the pressure data from the pressure signals.

18. The method defined in claim 16, further comprising adjusting an orientation of the movable pressure-sensing mounting stage based on the gathered pressure data.

19. The method defined in claim 16 wherein securing the assembly in the fixed position comprises temporarily attaching the assembly to a fixed pressure-sensing mounting stage.