A cutting device for processing TFT liquid crystal display screen

Abstract

The application discloses a cutting device for TFT liquid crystal display screen processing, which comprises a rack, a workbench, a gantry beam, a laser cutting head, an electrostatic cleaning unit and a supporting air float nozzle. The workbench is fixed to the rack and is provided with a slot along a cutting path. The gantry beam is arranged above the workbench. The laser cutting head is installed on the gantry beam through a sliding seat and a module. The electrostatic cleaning unit comprises a support, a silicon nitride ceramic roller and an electrostatic adsorption cleaning head, and moves synchronously with the gantry beam. The supporting air float nozzle is located below the workbench and sprays a micro-positive pressure airflow to the lower surface of a substrate through the slot. A symmetrical pressure difference is formed at the cutting path by the vacuum adsorption above the workbench. The application constrains the local warping of the substrate to the micron level by the symmetrical pressure difference, ensures the stability of the laser focal point, realizes uniform cutting, and removes the debris in a non-contact manner by the silicon nitride ceramic roller and the electrostatic adsorption cleaning head. The technical problem of the mutual contradiction between flatness maintenance and debris removal in the cutting process of the ultra-thin flexible substrate is solved, and the functional layer damage is effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of display screen processing technology, and in particular to a cutting device for processing TFT liquid crystal displays. Background Technology

[0002] In the production line of flexible TFT display, ultra-thin flexible glass substrates with a thickness of 0.05 to 0.1 mm need to be laser-cut to form screen units. In the existing technology, the ultra-thin flexible substrate is kept flat by adsorption through a porous ceramic vacuum platform, and the gantry laser cutting head ablates the substrate along a preset path. After cutting, the ablation debris is removed by air blowing or brushing.

[0003] However, existing devices are only equipped with a single-sided vacuum adsorption platform, which still cannot eliminate micron-level local warping. The laser focus deviates due to substrate undulations, resulting in uneven cutting depth and linewidth, and even penetration into the functional layer. The high-speed airflow generated when blowing away debris causes the substrate to arch, while brush contact removal scratches the thin film encapsulation layer. Although increasing the vacuum adsorption force can improve flatness to some extent, it will produce adsorption marks on the ultrathin substrate and damage the functional layer. The above defects result in a contradictory mechanical interference between debris removal and substrate flatness maintenance, making it difficult to meet both requirements simultaneously in the cutting of ultrathin flexible substrates. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is that during the cutting process of ultra-thin flexible substrates, debris removal and flatness cannot be maintained at the same level.

[0005] The above-mentioned technical problems are solved by the following technical solution: This invention proposes a cutting device for processing TFT liquid crystal displays, comprising: frame; The worktable is fixed to the upper surface of the frame, and a clearance groove is provided on the worktable along the cutting path direction, penetrating its upper and lower surfaces. The gantry beam spans above the worktable and reciprocates in a straight line in the Y direction relative to the worktable. The laser cutting head is mounted on the gantry beam via an X-axis slide and a Z-axis linear module, and is used for laser cutting of the substrate. An electrostatic cleaning unit includes an electrostatic cleaning unit bracket, a silicon nitride ceramic roller, and an electrostatic adsorption cleaning head. The electrostatic cleaning unit bracket is fixed to the rear of the gantry beam. The silicon nitride ceramic roller is rotatably mounted on the lower part of the electrostatic cleaning unit bracket. The electrostatic adsorption cleaning head is disposed on the electrostatic cleaning unit bracket and cooperates with the silicon nitride ceramic roller to adsorb debris on the surface of the substrate. A support air-bearing nozzle is located below the worktable, with its outlet facing upwards and directly opposite the clearance groove. It is used to spray a micro-positive pressure airflow onto the lower surface of the substrate to form a pneumatic support for the substrate at the cutting path.

[0006] In a preferred embodiment of the cutting device for processing TFT liquid crystal displays according to the present invention: it further includes a Y-axis linear guide, a Y-axis servo screw, and a Y-axis servo motor. The Y-axis linear guide is fixed to the frame along the Y-axis. The gantry beam is slidably connected to the Y-axis linear guide. The Y-axis servo motor is fixed to the end of the frame. The Y-axis servo motor drives the Y-axis servo screw. The Y-axis servo screw is driven by the gantry beam to drive it to move along the Y-axis.

[0007] In a preferred embodiment of the cutting device for TFT LCD screen processing described in this invention: an X-axis guide rail is fixed on the gantry beam along the X direction, the X-axis slide block is slidably fitted on the X-axis guide rail, the Z-axis linear module is fixed on the X-axis slide block, the laser cutting head is installed on the moving end of the Z-axis linear module, and the Z-axis linear module drives the laser cutting head to adjust its micro-displacement along the Z direction.

[0008] In a preferred embodiment of the cutting apparatus for TFT liquid crystal display processing of the present invention: the two ends of the silicon nitride ceramic roller are mounted on the lower part of the electrostatic cleaning unit bracket through insulating ceramic bearing seats, the axis of the silicon nitride ceramic roller extends along the X direction, and the lower edge of the silicon nitride ceramic roller maintains a non-contact gap with the substrate surface.

[0009] In a preferred embodiment of the cutting device for TFT liquid crystal display processing of the present invention: the electrostatic cleaning unit further includes a micro servo motor, the micro servo motor is fixed on the electrostatic cleaning unit bracket, and the output shaft of the micro servo motor is connected to the shaft end of the silicon nitride ceramic roller to drive the silicon nitride ceramic roller to rotate.

[0010] In a preferred embodiment of the cutting apparatus for TFT liquid crystal display processing of the present invention: the electrostatic cleaning unit further includes a scraper, an elastic element, and a negative pressure debris collection box. The scraper is mounted on the electrostatic cleaning unit bracket via the elastic element. The elastic element provides an elastic preload to press the blade of the scraper against the outer surface of the silicon nitride ceramic roller. The negative pressure debris collection box is fixed on the electrostatic cleaning unit bracket and located below the scraper.

[0011] In a preferred embodiment of the cutting device for TFT liquid crystal display processing of the present invention: it further includes a sensor bracket and a laser displacement sensor. The sensor bracket is fixed to the front end of the gantry beam, and a plurality of laser displacement sensors are arranged at equal intervals along the X direction on the sensor bracket and located in front of the laser cutting head traveling in the Y direction.

[0012] In a preferred embodiment of the cutting device for processing TFT liquid crystal displays according to the present invention: the supporting air float nozzle is installed on the top of the lower X-axis slider, the lower X-axis slider is slidably engaged with the lower X-axis guide rail, and the lower X-axis guide rail extends along the X-axis and is located below the worktable.

[0013] In a preferred embodiment of the cutting device for TFT liquid crystal display processing of the present invention: the supporting air-floating nozzle is configured to move synchronously with the gantry beam, and the lower X-axis slider drives the supporting air-floating nozzle to move along the X-axis, so that the supporting air-floating nozzle is always directly facing the cutting position below the laser cutting head in the XY plane.

[0014] In a preferred embodiment of the cutting apparatus for TFT liquid crystal display processing of the present invention: the relief groove extends along the X direction and penetrates the worktable, the cross-section of the relief groove is rectangular, the worktable surfaces on both sides of the relief groove form an adsorption area, and the micro-positive pressure airflow injected by the supporting air flotation nozzle acts on the lower surface of the substrate through the relief groove to form a symmetrical pressure difference.

[0015] The beneficial effects of this invention are as follows: By supporting the air-floating nozzle and applying adjustable micro-positive pressure to the lower surface of the substrate through the clearance groove, a symmetrical pressure difference is formed at the cutting path with the vacuum adsorption above the worktable. This solves the technical problem that single-sided vacuum adsorption cannot eliminate local warping of ultra-thin flexible substrates, thus constraining local warping of the substrate at the cutting path to the micrometer level. The laser focus is stabilized on the substrate surface, and the cutting depth and line width remain uniform. At the same time, the worktable only needs to maintain a conventional negative pressure level to ensure the flatness of the substrate, avoiding damage to the functional layer due to excessive adsorption force. This invention uses a silicon nitride ceramic roller in conjunction with an electrostatic adsorption cleaning head to remove debris in a non-contact manner, solving the technical problem that contact or airflow-type debris removal methods cause deformation or damage to fragile substrates. The synergistic effect of the two methods eliminates the contradictory mechanical interference between debris removal and flatness maintenance. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Wherein: Figure 1 A schematic diagram of the overall structure of the present invention is shown; Figure 2 A front view structural schematic diagram of the present invention is shown; Figure 3 A cross-sectional structural schematic diagram of the present invention is shown. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0018] The terminology used in this invention refers to those general terms currently widely used in the art in consideration of the function of the invention; however, these terms may vary according to the intent, precedent, or new technology of those skilled in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the invention. Therefore, the terms used in this specification should not be construed as simple names, but rather based on their meanings and the overall description of the invention. like Figure 1 As shown, the frame 1 serves as the supporting reference for the entire machine, forming a stable frame structure. The hollow porous ceramic vacuum worktable 2 is fixed to the upper surface of the frame 1. It is integrally sintered from a micron-level porous ceramic plate, and its back is connected to a vacuum pump to form a uniformly distributed negative pressure surface. Compared with traditional mechanical clamping or point adsorption, the vacuum adsorption method of porous ceramic material can provide a uniformly distributed negative pressure, effectively preventing adsorption marks or damage to the functional layer of the ultra-thin substrate during the fixing process. In order to solve the problem of local warping of the substrate due to insufficient rigidity during the cutting process, the present invention provides a relief groove 3 through the upper and lower surfaces of the hollow porous ceramic vacuum worktable 2 along the cutting path direction. The width of the relief groove 3 is preferably controlled between 3 and 5 mm. This specific width range is precisely calculated to provide sufficient airflow path for the supporting airflow below, and to control the discontinuity span of the porous ceramic adsorption area on both sides of the relief groove within a small range, preventing the substrate from being suspended and deformed at the groove opening due to loss of adsorption.

[0019] like Figure 2 and Figure 3As shown, the gantry beam 5 spans above the worktable 2 and is driven by the Y-axis linear guide rail 4, the Y-axis servo screw 6, and the Y-axis servo motor 7, performing high-precision linear reciprocating motion along the Y-axis. The laser cutting head 11 is mounted on the gantry beam 5 via the X-axis slide block 9 and the Z-axis linear module 10, enabling arbitrary trajectory cutting in the XY plane and focus adjustment in the Z-axis. The air-bearing nozzle is supported and located below the worktable, with its outlet facing the clearance groove 3. The air-bearing nozzle is mounted on the top of the lower X-axis slider and driven by a voice coil motor. The voice coil motor can drive the air-bearing nozzle to perform micro-displacement linear reciprocating motion along the Z-axis, with extremely fast response speed. To ensure strict synchronization of the Y-axis movement, the lower beam of the lower height compensation support unit is connected to the gantry beam 5 via... Each Y-axis nut shares the same Y-axis servo screw 6. The pitch and direction of the two threads on the Y-axis servo screw 6 corresponding to the two Y-axis nuts are consistent. When the Y-axis servo motor 7 drives the screw to rotate, the two Y-axis nuts generate linear displacement in the same direction and distance, eliminating the delay deviation that may be introduced by electrical synchronization. This ensures that the supporting air-bearing nozzle is always directly facing the cutting position below the laser cutting head in the Y direction, achieving dynamic balance. During operation, the supporting air-bearing nozzle sprays a micro-positive pressure airflow onto the lower surface of the substrate through the clearance groove. This airflow, together with the vacuum adsorption above the worktable, forms a symmetrical pressure difference at the cutting path. This balances the forces on the upper and lower surfaces of the substrate, constraining the local warping of the substrate at the cutting path to the micrometer level, and ensuring the stability of the laser focus.

[0020] To ensure the continuous and stable operation of the silicon nitride ceramic roller 13, the electrostatic cleaning unit also includes a scraper 15, an elastic element 22, and a negative pressure debris collection box 23. The scraper 15 is mounted on the electrostatic cleaning unit bracket 12 via the elastic element 22, preferably a leaf spring. The elastic element 22 is compressed along the normal direction, and the elastic preload it provides keeps the blade of the scraper 15 constantly pressed against the outer surface of the silicon nitride ceramic roller 13. Even if there is a slight roundness deviation on the roller surface, the elastic deformation of the elastic element 22 can compensate for it, ensuring that the blade always fits against the roller surface, completely peeling off the adsorbed debris and letting it fall into the negative pressure debris collection box 23 below. The micro servo motor 16 drives the silicon nitride ceramic roller 13 to rotate via a synchronous belt drive, working with the scraper 15 to achieve continuous automatic debris recovery and prevent secondary contamination of the substrate by debris. To ensure that the airflow supporting the air flotation nozzle 21 can accurately act on the cutting line position... The lower height compensation support unit employs a precision follow-up mechanism. Specifically, the support air float nozzle 21 is mounted on the top of the lower X-axis slider 20, which slides on the lower X-axis guide rail 19. To achieve strict synchronization in the Y-axis, the lower crossbeam and the gantry crossbeam of the lower height compensation support unit preferably share the same Y-axis servo screw via their respective nuts. This purely mechanical coupling method eliminates the delay deviation that may be introduced by electrical synchronization, ensuring that the support air float nozzle 21 is always directly facing the cutting position below the laser cutting head 11. At the same time, the support air float nozzle 21 is mounted on the top of the lower X-axis slider 20 via a voice coil motor. With the data collected by the laser displacement sensor 18, the voice coil motor can drive the support air float nozzle 21 to make micro-displacement adjustments along the Z-axis, adjusting the air film support height in real time according to the actual undulations of the substrate surface, further improving the response speed and accuracy of flatness control.

[0021] like Figure 2 and Figure 3As shown, the electrostatic cleaning unit bracket 12 is fixed behind the gantry beam 5. The two ends of the silicon nitride ceramic roller 13 are mounted on the lower part of the bracket via insulating ceramic bearing seats 14, with its axis extending along the X-direction. The electrostatic adsorption cleaning head 24 is a functional component for cleaning the silicon nitride ceramic roller 13, forming a cleaning structure that generates static electricity in conjunction with a conductive slip ring. Specifically, a high-voltage electrode is embedded inside the silicon nitride ceramic roller 13 and connected to a high-voltage DC power supply fixed on the gantry beam via a conductive slip ring. The high-voltage electrode establishes a strong electrostatic field between the lower edge of the roller and the substrate surface. A non-contact gap of 0.2 to 0.5 mm is maintained between the lower edge of the silicon nitride ceramic roller 13 and the substrate surface, ensuring that the strong electrostatic field can effectively adsorb the substrate across the gap. The residual charge of the debris particles ensures that there is no physical contact between the roller and the fragile substrate, completely avoiding the risk of scratches. A scraper is installed above the silicon nitride ceramic roller 13. The scraper is mounted on the bracket through an elastic element. The elastic restoring force keeps the scraper blade pressed against the outer surface of the roller. Even if there is a slight roundness deviation on the roller surface, the elastic element can compensate to ensure that the blade is always in contact, completely peeling off the adsorbed debris and letting it fall into the negative pressure debris collection box below, realizing continuous automatic recycling. In order to achieve height compensation, a sensor bracket 17 is fixed at the front end of the gantry beam 5. Multiple laser displacement sensors 18 are arranged equidistantly along the X direction. The data processor receives the height data collected by the sensors and integrates it into a distribution map.

[0022] In operation, the ultrathin flexible glass substrate to be processed is placed on a perforated ceramic vacuum worktable. The vacuum pump is activated, and gas is extracted through the micron-level pores of the worktable, creating a uniform negative pressure on the surface. This negative pressure firmly adheres the flexible substrate, with a thickness of only .mm, to the worktable surface, maintaining its macroscopic flatness. However, due to the extremely low rigidity of the ultrathin substrate, micron-level local warping or undulations still exist at the microscopic level due to its own gravity or internal stress. Before the cutting operation begins, the system performs a pre-scan stroke. The Y-axis servo motor drives the Y-axis servo screw to rotate, causing the gantry beam to move slowly along the Y-axis. Multiple laser displacement sensors fixed to the front end of the gantry beam scan the substrate surface below line by line, collecting micro-distance data at each position. The sensor signals are transmitted to the data processor on the side of the frame via wiring channels and cable chains. The data processor integrates the discrete height data points to construct a full-width height distribution map of the substrate surface. As the reference data for subsequent cutting height compensation, after entering the cutting stroke, the Y-axis servo motor drives the gantry beam to move, while the X-axis servo motor drives the X-axis slide to move. The laser cutting head moves along a preset trajectory in the XY plane, and the light outlet emits laser light downwards to ablate the substrate. During this process, the data processor reads the current XY coordinates of the laser cutting head in real time and queries the height deviation value of the coordinate point from the pre-stored substrate surface height distribution map. The data processor executes bidirectional linkage compensation control and focus Z-axis adjustment. The first compensation command is sent to the driver of the Z-axis linear module. The Z-axis linear module drives the laser cutting head to make a micro-displacement and rise along the Z-axis, correcting the Z-axis position of the laser focus in real time so that it is always accurately aligned with the substrate surface and supporting Z-axis adjustment. The second synchronous reverse compensation command is sent to the driver of the voice coil motor. If the laser cutting head moves down to track the recessed area, the voice coil motor drives the support air float nozzle to move up to reduce the air film gap and enhance the support force. The lower height compensation support unit works in conjunction with the upper vacuum adsorption system to form a symmetrical pressure differential field. To eliminate electrical synchronization delays, the lower crossbeam and the gantry crossbeam share the same Y-axis servo screw via their respective Y-axis nuts. When the screw rotates, the upper and lower nuts produce completely consistent displacements, ensuring that the support air-bearing nozzle is always precisely aligned with the clearance groove and the laser cutting head above in the Y-axis direction. The support air-bearing nozzle sprays a micro-positive pressure airflow upwards. This airflow passes through the clearance groove on the worktable, which is only a few millimeters wide, and reaches the lower surface of the substrate. The upper surface of the substrate is adsorbed by the negative pressure of the worktable, and the lower surface is supported by the micro-positive pressure of the nozzle. This creates an upper and lower clamping force on the substrate at the cutting path, constraining the original micron-level local warping to its limit position, so that the substrate is initially... To maintain a smooth mirror surface, the electrostatic cleaning unit located behind the laser cutting head moves closely along the cutting path. High-voltage electrodes embedded inside the silicon nitride ceramic roller are connected to a high-voltage DC power supply via conductive slip rings, establishing a strong electrostatic field between the lower edge of the roller and the substrate surface. The molten debris particles generated by laser ablation carry residual charges. When passing under the silicon nitride ceramic roller, the Coulomb force generated by the strong electrostatic field crosses the non-contact gap of . to . mm, forcibly lifting the debris particles from the substrate surface and adhering them to the outer surface of the rotating roller. A micro servo motor drives the silicon nitride ceramic roller to rotate continuously via a synchronous belt. The area where debris is adhered moves upward with the roller and is peeled off by a scraper pressed by a leaf spring. The peeled debris falls into a negative pressure debris collection tank and is sucked away by an independent suction pipe.

[0023] Finally, it should be noted that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A cutting device for processing TFT liquid crystal displays, characterized in that: include: frame; The worktable is fixed to the upper surface of the frame, and a clearance groove is provided on the worktable along the cutting path direction, penetrating its upper and lower surfaces. The gantry beam spans above the worktable and reciprocates in a straight line in the Y direction relative to the worktable. The laser cutting head is mounted on the gantry beam via an X-axis slide and a Z-axis linear module, and is used for laser cutting of the substrate. An electrostatic cleaning unit includes an electrostatic cleaning unit bracket, a silicon nitride ceramic roller, and an electrostatic adsorption cleaning head. The electrostatic cleaning unit bracket is fixed to the rear of the gantry beam. The silicon nitride ceramic roller is rotatably mounted on the lower part of the electrostatic cleaning unit bracket. The electrostatic adsorption cleaning head is disposed on the electrostatic cleaning unit bracket and cooperates with the silicon nitride ceramic roller to adsorb debris on the surface of the substrate. A support air-bearing nozzle is located below the worktable, with its outlet facing upwards and directly opposite the clearance groove. It is used to spray a micro-positive pressure airflow onto the lower surface of the substrate to form a pneumatic support for the substrate at the cutting path.

2. The cutting device for processing TFT liquid crystal displays according to claim 1, characterized in that: It also includes a Y-axis linear guide, a Y-axis servo screw, and a Y-axis servo motor. The Y-axis linear guide is fixed to the frame along the Y-axis. The gantry beam is slidably connected to the Y-axis linear guide. The Y-axis servo motor is fixed to the end of the frame. The Y-axis servo motor drives the Y-axis servo screw. The Y-axis servo screw is connected to the gantry beam to drive it to move along the Y-axis.

3. The cutting device for processing TFT liquid crystal displays according to claim 2, characterized in that: An X-axis guide rail is fixed along the X-axis of the gantry beam. The X-axis slide block is slidably fitted onto the X-axis guide rail. The Z-axis linear module is fixed onto the X-axis slide block. The laser cutting head is mounted on the moving end of the Z-axis linear module. The Z-axis linear module drives the laser cutting head to adjust its micro-displacement along the Z-axis.

4. The cutting device for processing TFT liquid crystal displays according to claim 1, characterized in that: The two ends of the silicon nitride ceramic roller are mounted on the lower part of the electrostatic cleaning unit bracket through insulating ceramic bearing seats. The axis of the silicon nitride ceramic roller extends along the X direction, and the lower edge of the silicon nitride ceramic roller maintains a non-contact gap with the substrate surface.

5. The cutting device for processing TFT liquid crystal displays according to claim 4, characterized in that: The electrostatic cleaning unit also includes a micro servo motor, which is fixed on the electrostatic cleaning unit bracket. The output shaft of the micro servo motor is connected to the shaft end of the silicon nitride ceramic roller to drive the silicon nitride ceramic roller to rotate.

6. The cutting apparatus for processing TFT liquid crystal displays according to claim 5, characterized in that: The electrostatic cleaning unit also includes a scraper, an elastic element, and a negative pressure debris collection box. The scraper is mounted on the electrostatic cleaning unit bracket via the elastic element, and the elastic element provides an elastic preload to press the blade of the scraper against the outer surface of the silicon nitride ceramic roller. The negative pressure debris collection box is fixed on the electrostatic cleaning unit bracket and located below the scraper.

7. The cutting apparatus for processing TFT liquid crystal displays according to claim 1, characterized in that: It also includes a sensor bracket and a laser displacement sensor. The sensor bracket is fixed to the front end of the gantry beam, and multiple laser displacement sensors are equidistantly arranged on the sensor bracket along the X direction and located in front of the laser cutting head in the Y direction.

8. The cutting apparatus for processing TFT liquid crystal displays according to claim 1, characterized in that: The supporting air flotation nozzle is installed on the top of the lower X-axis slider, the lower X-axis slider is slidably engaged with the lower X-axis guide rail, and the lower X-axis guide rail extends along the X-axis and is located below the worktable.

9. The cutting apparatus for processing TFT liquid crystal displays according to claim 8, characterized in that: The supporting air-floating nozzle is configured to move synchronously with the gantry beam. The lower X-axis slider drives the supporting air-floating nozzle to move along the X-axis, so that the supporting air-floating nozzle is always facing the cutting position below the laser cutting head in the XY plane.

10. The cutting apparatus for processing TFT liquid crystal displays according to claim 1, characterized in that: The clearance groove extends along the X direction and penetrates the worktable. The cross-section of the clearance groove is rectangular. Adsorption areas are formed on the worktable surfaces on both sides of the clearance groove. The micro-positive pressure airflow injected by the supporting air flotation nozzle acts on the lower surface of the substrate through the clearance groove to form a symmetrical pressure difference.

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