TWI441269B - Continuous linear scanning of large flat panel media - Google Patents

Description

Continuous linear scanning of large flat panel media Cross-references to related applications

This application is filed under Section 119(e) of Title 35 of the United States Code and claims the following co-transfer, Application No. 60/862,427, filed on October 20, 2006, entitled "Continuous Linear Scanning Of Large Flat Panel" The priority of the "Media" is hereby incorporated by reference in its entirety in its entirety herein in its entirety.

This application is hereby incorporated by reference in its entirety in its entirety, the entire disclosure of which is hereby incorporated by reference in its entirety in the entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire entire Incorporated into this specification.

This application is related to the following: "Vacuum Gripping System For Positioning Large Thin Substrates On A Support Table", the entire contents of which are commonly assigned to the United States Application No. 11/389,556, dated March 23, 2006. This specification is incorporated herein by reference.

This application is hereby incorporated by reference in its entirety in its assigned application Serial No. 11/486,206, filed on Aug. 29, 2006, entitled "Substrate Alignment Using Linear Array Sensor", the entire contents of which are hereby incorporated by reference. Enter this manual.

Background of the invention

In the completed liquid crystal flat panel, a thin layer of liquid crystal (LC) material is placed between the two glass sheets. On one of the glass sheets, one or more two-dimensional electrode arrays are patterned, each of which is referred to as a panel. Each of the electrodes may be on a 100 micron scale and may have a unique voltage applied through a multiplexed transistor disposed along the edge of the panel. In the finished product, the electric field generated by each electrode is coupled into the LC material and modulates the amount of light transmitted in the lattice region. This effect produces a visible image on the flat panel as a whole on an overall two-dimensional array.

A major portion of the manufacturing cost of liquid crystal display (LCD) panels occurs when the LC material is injected between the upper and lower glass sheets. Therefore, it is important to identify and correct any image quality issues prior to this manufacturing step. The problem with detecting an LCD panel prior to deposition of LC material is that no visible image is available for inspection without LC material. Prior to deposition of the LC material, there is an electric field generated by the voltage imparted to the pixel that is unique to the voltage on the pixel.

To overcome this limitation, Photon Dynamics has developed a floating modulator that includes a relatively large piece of optically flat glass with a thin layer of LC material formed on its surface, as shown in Figure 1A. When the patterned glass plate 10 is to be detected, the modulator 15 having a size smaller than the flat panel is physically moved over the portion to be inspected of the panel, and then lowered to a distance of a few micrometers from the surface of the flat panel, as shown in FIG. 1B. . A drive signal is applied to the electrode on the panel. A smaller air gap 25 between the flat panel electrode 30 and the LC modulator 15 is typically 10 to 50 microns, allowing the electric field of each pixel electrode 30 on the patterned glass sheet 10 to be coupled to the modulator 15 In order to make the panel produce a temporary visible display. This visible display is then captured by camera 35 to identify the defect. After the detection area is completed, the modulator 15 is raised and moved to another area of the panel, and the program repeats. Through this step-and-repeat procedure, the entire LC panel can be tested to find defects. In FIGS. 1A and 1B, the LC modulator 15 is shown to include an LC material 45 and a flat glass 50.

The use of the above modulators to detect LCD panels at high speeds presents several technical challenges. For example, when the detection of a location is completed, the modulator, which may weigh several pounds and is very close to the panel at the time of detection, is first raised to ensure that the modulator does not damage the glass panel and then moves Move to the next position and down in the direction of the panel for the next detection action. These actions, together with the time required to stabilize these actions, will affect the throughput of the system. Currently known step stabilizers do not naturally produce continuous linear sweeps, which provides much higher system throughput, primarily because of their much smaller size than large substrates.

In the above modulator, the visible image of the thin layer of the LCD is obtained by reflecting light from the surface of the LC material. The LC material acts as a scattering medium in its closed state and acts as a transmission medium in its open state. This will typically result in the generation of a dc component of the light modulated by a relatively small amount of information. For the camera 35, this means that the image generator must be able to process relatively large signals (for the DC component) even if the signal containing the information is relatively weak. Moreover, the relatively large DC component of the light component may carry a corresponding amount of bulk acoustic noise, which must be overcome to reproduce the defect data of the flat panel.

Another panel test method uses an electron beam and imaging device to detect defects. A typical electron beam tester includes a number of electron beam/developing heads that are stepped along the surface of the panel and require a drive signal to be applied to the panel, such as a tester based on an electronic optical modulator. However, since the beam head size may be small, several electron beam heads may span across the width of a panel, so the lateral step size will be more in the electron beam tool than in the modulator-based tool. Medium is less. Electron beam-based tools require vacuum and the electron beam sensor head cannot fully span the width of the flat panel.

Summary of invention

In accordance with the present invention, a continuous linear scanning system is designed to process, support, transport, position and limit relatively large and generally flat and thin articles for performing tests or inspections. In particular, the present invention provides apparatus and methods that use one or more linear arrays of non-contact sensors to perform electrical function detection, or automated optical inspection (AOI) or large flat, flexible, and/or A measure of patterned media, such as a glass panel containing a structure for forming a thin film transistor (TFT) array to form a part of a liquid crystal flat panel display (LCD). The invention is applicable to high throughput linear testing of TFT/LCD panels, OLED based TFT panels, solar panel panels and any other flat media in various stages of production.

In accordance with an embodiment of the invention, a system portion for performing a continuous full linear scan of a flat medium having a plurality of pixels includes a pad and at least first, second, and third lifting gantry. The pad is used to support the flat media during testing. The first lifting gantry includes at least one linear array of non-contact sensors that span the width of the flat media and are configured to be movable over the entire length of the flat media. The second lifting gantry includes a probe head that spans the width of the flat media and is configured to apply an electrical signal to the flat media. The probe head is further configured to move in a direction substantially perpendicular to a surface of the flat media as the first gantry is in motion. The third lifting gantry also includes a probe head that spans the width of the flat media and is configured to apply an electrical signal to the flat media. The probe head is further configured to move in a direction substantially perpendicular to a surface of the flat media as the first gantry is in motion.

In one embodiment, the system further includes at least an actuator and a feedback control circuit coupled to the actuator to maintain a distance between the linear array of non-contact sensors and the flat medium Set within the scope. In an embodiment, the at least one actuator comprises a pneumatic actuator. In another embodiment, the at least one actuator includes a pneumatic actuator and a voice coil. In yet another embodiment, the at least one actuator includes a pneumatic actuator and a piezoelectric actuator.

In an embodiment, the feedback control circuit is integrated with the linear array of non-contact sensors. In one embodiment, the system further includes a control circuit that controls movement of the first and second lifting gantry to effect continuous scanning of the flat media when power is supplied to the flat media.

In one embodiment, the linear array of contactless inductors is formed by a linear inductor assembly that is coupled to each other and aligned to each other across the overall width of the flat media. In another embodiment, the first lifting gantry further includes a linear array of second non-contact sensors, wherein the inductor spans the width of the flat media. In such embodiments, the second non-contact sensor linear array can also be formed from a linear inductor assembly that is coupled to each other and aligned to each other across the overall width of the flat media.

In an embodiment, the system further includes first and second cylinders. The first cylinder is configured to move a plurality of probes on the first probe head such that they contact or not contact a plurality of pads on the flat media. The second cylinder has a stroke greater than the stroke of the first cylinder for moving the first probe head to a level lower than a top surface of the spacer.

Simple illustration

Figure 1A shows a floating modulator located above a patterned glass plate, as is known in the art; Figure 1B shows that the floating modulator is located near the patterned glass plate in Figure 1A to perform the test, As is known in the art; FIG. 1C shows a conventional system for electrical testing of flat panels; and FIG. 2 shows a system with continuous linear scanning to test panels according to an embodiment of the invention; 1 is a side view of a linear scanning sensor according to an embodiment of the present invention; FIG. 3B is a side view of a linear scanning sensor according to another embodiment of the present invention; FIG. 3C is a side view showing a side view A linear sensor array including a single line sensor array according to an embodiment of the invention; FIG. 3D is a side view showing a linear sensor including a multi-line sensor array forming a two-dimensional sensor array according to another embodiment of the present invention Array; Figure 4 shows the layout of a block using triangular bricks; Figures 5A through 5C show various illustrations of a block using triangular bricks; Figure 6 shows a block using a plurality of rigid beams; And 7B map A perspective view of a diaphragm/pneumatic flight control device, wherein the diaphragm/pneumatic flight control device is used in a continuous linear scanning system in accordance with an embodiment of the present invention in FIG. 2; and FIG. 7C is in FIGS. 7A and 7B. A cross-sectional view of a diaphragm/pneumatic flight control device; FIGS. 8A and 8B are perspective and cross-sectional views of a composite pneumatic/voice coil flight control device in accordance with an embodiment of the present invention; and FIG. 9 is another perspective view of the present invention. A perspective view of a hybrid pneumatic/piezoelectric actuator flight control device of an embodiment; FIG. 10 shows a brush device; and FIG. 11A shows a linear array sensor for reading and providing a feedback position for alignment The top view of the spacer penetrating the grip; Figure 11B is a top view of the spacer having a fiducial mark for a visualization system to read and provide a feedback position for alignment of the spacer; 12 and 13 2 is a top view of the probe bar and the sensor head of the continuous linear scanning system according to an embodiment of the invention; FIG. 14 is a flow chart illustrating the continuous application of the test signal to the second The continuous linear scanning system test level in the figure Steps of the panel; Figure 15 is a simplified perspective view illustrating a scanning system including three lifting gantry sharing the same encoder and track; FIGS. 16A and 16B are cross-sectional and top views showing the bearing The lifting gantry of the sink probe is located at an upward position and at the same level as the gantry carrying the linear sensor array; the 16C and 16D are cross-sectional and top views showing the bearing The lifting gantry of the sinking probe bar is located at a lower position than the lifting gantry carrying the linear sensor array; and FIG. 17 shows an exemplary multi-piece lifting gantry Foot platform.

Detailed description of the preferred embodiment

In accordance with the present invention, relatively large and generally flat and thin flexible articles or media can be processed, supported, transported, positioned and constrained using a continuous linear scan with relatively high mechanical precision. In particular, the present invention provides an apparatus and method that uses a linear inductor, such as the linear sensor disclosed in U.S. Patent Application Serial No. 11/379,413, for transmission and limitation to perform electrical function detection, or automatic Optical inspection (AOI) or measurement of large flat, flexible, and/or patterned media, such as glass panels containing structures used to form thin film transistor (TFT) arrays to form parts of liquid crystal flat panel displays (LCDs) . The invention is applicable to high throughput linear testing of TFT/LCD panels, OLED based TFT panels, solar panel panels and any other flat media in various stages of production.

The scanning system requires a linear sensor (or detector) assembly that completely spans any of the flat panel media. The linear sensor (or detector) is then scanned or moved in the second dimension. The panel can be moved relative to the linear sensor or moved relative to the panel. In the case of an oversized thin panel, such as a flat panel display panel that may be as large as 3 by 3 meters and less than 1 mm thick, moving the linear inductor relative to the panel is more cost effective.

Contactless capacitive coupling technology has been developed to test LCD flat panel arrays. U.S. Application Serial No. 11/379,413 discloses a linear capacitive sensor that can be used, for example, for flat panel testing. In one embodiment disclosed in this application, a linear array of inductors that can completely span one dimension of a flat panel is brought close to (eg, from 10 microns to 100 microns) the flat panel under test, and then The flat panel is supplied with electrical signal energy, and the electric field generated by the panel electrodes is capacitively measured. A scan rate of about 100 millimeters per second or about 100 micrometers per millisecond can be used. These linear sensors require appropriate methods and devices to handle large flat panels.

2 shows a system 200 that includes a non-contact linear sensor 240 that is used to scan a large flat panel or media (hereinafter also referred to as a panel) 10. The flat panel 10 is placed on a pad surface 206 that forms part of the platform 208. The linear inductor 240 is fixed to the heavy gantry 202 and spans the overall width of the panel along the X-axis direction. The lifting gantry 202 is configured to move over the entire length of the panel in the Y-axis direction without contacting the panel. In accordance with an aspect of the invention, the gap (distance) between the linear sensor 240 and the panel 10 is maintained at a predetermined range to meet various requirements such as field depth of the development or sensitivity of the capacitance test. This requires (i) control of the flat dimensions of the large panel and its docked flat surface (or pad), as well as the stability of the flight control mechanism that maintains the gap between the sensor and the panel; (ii) the sensor view The ability of the panel to be an integral surface; (iii) the ability to apply an electrical drive source through the probe bars 250, 260 for detection while the electrical test tool is being tested without interfering with scanning; (iv) shortening the first panel loading to test Completion of the architecture and sequence of steps required to load the second panel (the moving time); the ability to align the pattern on the panel with respect to the movement of the sensor; and find the position relative to the foot on the panel The ability to reference the location of the token.

3A and 3B are side views of the linear sensor array 240 in Fig. 2A. The embodiment of the linear sensor array in Figure 3A spans the overall width of the system 200 in Figure 2. The embodiment of the linear sensor array of FIG. 3B includes an assembly of linear inductors 302 that are respectively shorter than the overall width of the system and that are joined and aligned to span the overall width of the system 200. . Each of the linear sensors 302 includes a plurality of inductors 304 in the illustration. In one embodiment, the linear sensor array includes an array 306 of single line inductors 304, as shown in FIG. 3C. In another embodiment, as shown in FIG. 3D, the linear sensor array includes a multi-line array forming a two-dimensional array 308, wherein one dimension spans the overall width of the system. The linear inductor is typically non-contact and can be a capacitive or optical type, or a combination of these functions. For a continuous linear scanning system, the linear array may comprise a single line array of M lines, whether segmented or single piece, where M is greater than or equal to 1, but where M is much smaller than the sensor across the width of the system Quantity N. M is typically greater than one to initiate redundancy of the linear inductor.

For applications requiring high mechanical precision, a system including a large substrate 102 and a rigid lifting gantry 104 as shown in FIG. 1C provides a precision reference frame with high rigidity and flatness. In order to maintain rigidity in a large area, materials such as granite, polymer casting, steel, or carbon fiber are used for the substrate and the lifting frame. A vacuum pad holds the flexible medium to be inspected and provides a thin substrate flatness reference value. Conventional lifting gantry platforms, as shown in Figure 1C, are typically relatively larger than the flat panel size to achieve full coverage of the panel and to achieve full travel of the foot controller and mechanism. For example, a conventional lifting platform foot for a sixth generation size flat panel of approximately 1500 by 1850 mm may have an overall size of 2920 mm wide, 3050 mm long and may weigh up to 11 tons. However, in the main application area of the target, that is, the TFT/LCD glass panel test, the size of the glass sheet has increased with the industry's pursuit of larger, thinner glass, and therefore, to test or detect these poles. The size of the tools for large panels has also increased. For example, the tenth generation flat panel has a side edge of about 3 meters and can drive the footprint of an enlarged version of a conventional step-stabilized voltage developing optical system to a scale of up to 4 meters or more on one side.

Referring to Figures 3A through 3D, for the highest consistency and accuracy, a control distance 320 is required between the complete surface of the sample 10 and the non-contact image sensor or capacitive sensor 304 of the linear sensor 300 or 302. This distance tolerance is, for example, ±1.5 microns for a typical high resolution system with a 0.5 micron object plane resolution, and these resolution levels can further impart high accuracy and repeatability in Z-axis positioning and at X High rotational rigidity is imparted on the Y-axis. In the capacitive sensor disclosed in U.S. Application Serial No. 11/379,413, the typical operating gap is 20 to 100 microns, and this range must be maintained within ±2 microns.

The spacer 206 shown in Figure 2 generally provides the flat panel a rigid reference plane. In one embodiment, the spacer must have a flatness requirement of 50 microns, or, more preferably, an overall and maximum slope of 2.5 microns in the range of 25 mm. In general, the glass panel is moved to the spacer by a factory automation control arm. The air cushion between the spacer and the glass plate is completed by blowing air into the surface of the spacer. The glass floats on the air cushion and is then aligned with a mechanical device such as a grip or brush. Once aligned, the air will be closed and a vacuum will be applied to clamp the glass to its position for processing. Since the glass is very thin, the surface of the spacer can effectively serve as a reference for the alignment of the linear sensor. Any possibility that the surface of the spacer exceeds a maximum slope of 2.5 microns within 25 mm, such as due to uneven folding of the surface of the spacer or physical distortion of the spacer (deformation or sagging) or between brick joints in multiple brick blocks The irregular surface of the pad caused by the unevenness of the seam will be directly transferred to the uneven portion of the glass.

For the fifth generation (1200 by 1300 mm) and smaller glass substrates, a one-piece vacuum block that meets the flatness requirements can be made. In the case of the sixth generation of glass, multi-piece vacuum blocks have been developed in which individual pieces are pre-folded, glued and bolted together. The seam between the top panels is then precisely aligned or folded by hand and tested to meet the slope flatness requirements.

Larger glass substrates (greater than about 1870 mm) need to partially or completely exceed the size of the blocks that can actually be machined, ground, folded, and inspected. Large vacuum blocks can be made of smaller, easier to handle and easier to manufacture bricks that meet the stringent flatness requirements of the flat panel industry. The bricks can be separated and then aligned with at least 3 moving supports. The key is to achieve flatness specifications for all of the bricks, especially the seam. When each of the bricks was docked at three points, each of the bricks was folded and its flatness was measured. In order to achieve the required rigidity within a reasonable cost, the material type, shape, size and thickness of the spacer brick must be compromised.

The material of the spacer may include electroplated aluminum, ceramic, glass, and metal. The need for electrical insulation blocks and the general rigidity requirements and the electromagnetic interference possibilities of the test methods often limit the use of metal blocks. Alumina is a typical ceramic that provides a good coefficient of thermal expansion, good rigidity, and the ability to be folded into an extremely flat.

The brick can be, for example, rectangular or triangular, as shown in Figures 4 and 5A. The rectangle 406 shown in Figure 5 provides the advantage that the minimum number of bricks conforms to the shape of the panel. However, if the brick is too large (say, greater than about 750 mm), the three motion support points 404 will not be able to overcome the sag of the panel due to gravity. Large rectangular plates may require jacks or reinforcements in four corners. Alternatively, a triangular plate 402 as shown in Fig. 4 can be used, which has the advantage of maintaining flatness with the three motion supports without the need for reinforcement. Other embodiments that distribute the functionality of the motion support can be used. For example, a vertically adjustable reference substrate can be provided between the spacer surface plates, and the adjustment mechanism between the spacer and the substrate can only adjust the flatness.

Another challenge is to ensure that the seams 410 between two adjacent bricks meet the slope flatness requirements. In the case of seams, the shape of any brick is not necessarily better than the shape of another brick. Any edge of any brick that is attached to other brick edges needs to be made a smooth (flat) seam. Each of the bricks can be fabricated in the following manner: firstly, roughly shaped, followed by fine grinding to a final size and within 1 micron flatness, then sandblasting the top surface pattern, and finally folding the top surface. The step of producing the surface pattern changes the flatness of the 1 meter panel from 1 micron to 25 micrometers. Since the folding is usually a manual procedure, a convex or concave area may be formed. Flatness requirements are more difficult to control when using large-area bricks (say 1 by 1 meter). Moreover, since each of the bricks may typically be folded by hand, the folding profile of either brick adjacent to the seam may not necessarily match the folded contour of the adjacent brick.

To make alignment easy, it may be necessary to use a minimum of bricks to make the entire pad area. The giant blocks used in the tenth generation of glass are too large to fit the standard grinding, folding, testing or manufacturing machine. Multi-piece pads are more practical. The possible layout of triangular and rectangular bricks optimized for the minimum number of bricks and seam folds/fits is shown in Figures 4 and 5A. For detection and folding, an odd number of rectangles may be used in an embodiment to allow the folding sequence to be performed in groups, such as ABDE, BCEF, EFHJ, and DEGH as shown in Figure 5A. This folding sequence group can achieve overlapping coverage of the complete surface and thus achieve a more uniform surface at the seam.

The method of reducing the number of bricks means that the bricks may be relatively large, and thus it may be difficult to maintain flatness due to the difficulty of maintaining the contour variability of each brick. Once the folding is complete, the brick becomes a mating kit, and if either brick breaks, the entire mating kit will need to be replaced.

Another alternative is to optimize the maximum brick size that can be made within the required flatness specifications and reasonable cost. This flatness-optimized brick size may be smaller than the minimum optimized brick size. The use of this method can alleviate the need for a matching set. For example, a pad for processing a 300 mm semiconductor wafer is manufactured to a flatness specification at a reasonable cost, say 0.3 micron (equal to the 氦 wavelength of 632 nm ray Rays). In this case, to maintain the same slope flatness of 25 mm and 2.5 microns between the bricks and bricks, the 300 mm bricks may be spaced apart from each other by a distance of no more than 6 mm. Thus, the tenth generation of flat panel mats may include more than 100 alumina ceramic tiles, each of which is approximately 300 by 300 mm thick and has a tightly controlled flatness. The use of smaller bricks that meet the stricter flatness specifications respectively can alleviate the fit constraints, but imposes some burden on the time required to align the bulk bricks.

Regardless of how many or how many types of material are used to form the spacer, all of the spacers need to include a number of topographical bodies to manipulate and align the glass in the continuous scanning system and receive and transfer the glass to the Factory automatic control device. In order to align the glass, a penetrating hole of the grip or a side profile of the brush member is usually required. The distribution holes and passages of air and vacuum are also typically designed in the spacer. To reduce the overall surface contact between the flat panel sample and the vacuum block, a raised pattern can be formed on the surface of the block by a process such as pearl blasting. Fig. 5B is an enlarged view of a region 420 of the brick J in Fig. 5A, showing the ridge pattern 422. Figure 5C is a cross-sectional view of the region 420 along axis A-A'. Surface topography bodies (such as the penetrating apertures of the grip and air/vacuum paths and channels) may be located on the surface of the spacer to accommodate more than one glass substrate size. In order to perform continuous scanning for multiple glass size testing, or inspection, or processing, it is preferred to align the glass substrate forward to shorten the arm length travel distance of the automatic control device.

Another method of forming a large area vacuum block is to place the long ceramic guide beam shoulders side by side. In the example shown in FIG. 6, four long beams 602 are attached together to form a single block 600. The seam between the beams and columns can be folded. Channels 604, 606, 608 are included to deliver air and vacuum and reduce the overall weight of the beam.

As shown in FIG. 3, the non-contact linear inductor 300 or 302 is made to fly above the flat panel 10 at a fixed height 320 from the top surface of the panel. Gas bearing techniques traditionally used to achieve high flight consistency are generally too slow to respond to the exact gap tolerance at the required scanning speed. Thus, in accordance with an embodiment of the present invention, a system and method for controlling the height of the scanning sensor above the panel under test is provided.

Figure 7A is a perspective front elevational view of a flight control device 700 for controlling the flying height of a linear scanning sensor in accordance with an embodiment of the present invention. Figure 7B is a perspective rear view of the flight control device 700. Figure 7C is a cross-sectional view of the device 700. Referring also to Figures 7A and 7B, the linear scan sensor positioning is initiated by compressed air supplied to the air inlet 702 of the needle valve 704. The scanning sensor 240 is substantially fixed to the glass substrate by the connecting member 706 and the curved support rod 708. For example, at a distance of several hundred micrometers, the position of the connecting member 706 and the curved supporting rod 708 is controlled by the pneumatic actuator 710. . The curved portion 712 ensures that the scan sensor 240 moves only along an axis that is perpendicular to the panel. Each end of the scanning sensor 240 is driven by a pneumatic actuator 710 to control the gap height along the length of the scanning sensor 240. The scan sensor can be slightly tilted along its length and moved away from or toward the panel to maintain parallel with the panel. The link 706 driven by the pneumatic actuator 710 is coupled to each end of the scan sensor and converts the diaphragm (laterally, as shown in FIG. 7) into the support rod 708 and the inductor. 240 operates in the Z-axis direction to maintain the correct sensor distance and parallel from the scanning sensor to the panel.

Each of the distance sensing tubes 714 is configured to increase the air pressure and airflow from the inductor as the sensor moves closer to the panel. The distance sensing tube 714 is a simple tubular body through which air flows. The pressure in the connecting air tube 716 increases as the opening of the distance sensing tube moves closer to the panel surface and restricts air flow. The pressure from the distance sensing tube 714 is transferred to the pneumatic actuator 710 via the connecting air tube 716.

The positioning or notch formation of the scanning sensor is achieved by the pressure transmitted from the distance sensing tube 714 back to the pneumatic actuator 710 via the tube 716. The pneumatic actuator expands as the air pressure from the distance sensing tube increases as it moves closer to the panel, and then pulls the scanning sensor away from the panel. A compression preload spring 718 is used to force the ends of the scanning sensor into the panel. The notch function is a balance between the compression spring pushing the inductor into the panel and the force of the pneumatic actuator pulling the end of the scanning sensor out of the panel. The force per millimeter of movement of the actuator plus the distance sensor subsystem is designed to be extremely high, thereby providing proper repeatability in the closed loop system to overcome the hysteresis and friction of the mechanical parts.

The gap between the panel and the scanning sensor is adjusted by varying the inlet pressure of the needle valve 704, thereby changing the flow of air through the distance sensor. Optionally, the needle valve can also be adjusted to change the moving gap. The air supply pressure needs to remain constant over a typical range of pounds per square inch (psi) to maintain the gap at all times. The response time is limited by the speed of the pressure wave generated by the change in the gap of the distance sensor. The pressure wave travels through the connecting tube at the speed of sound. This response time can be shortened by shortening the connecting tube.

Multiple linear scan sensors may be required to span the overall width of the large flat panel. For example, an embodiment may use 40 of the linear scan sensors 302 to form a linear array 310, as shown in FIG. 3B. The linear scan sensors 302 are mutually calibrated. This is achieved by the use of, for example, the local height/gap sensing on the linear scanning sensor assembly as disclosed in U.S. Patent Application Serial No. 60/862,372. By placing a height/slit detector at the end of each linear scanning sensor assembly and by using two flight control devices in each linear scanning sensor (as shown in Figures 7A through 7C) The exit plane tilt of the sensor can be controlled by the end height/slot sensor and fed back to the flight control device. The plane (ie, x, y, rotation) alignment from one sensor assembly to another sensor assembly can be embedded and trimmed by embedding a strip of material with a suitably defined pattern on the edge of the spacer. Any offset is reached.

While pneumatic sensors and actuators accurately follow the contours of the panel topology, response times and typical bandwidths greater than 50 Hz may not be sufficient for the linear scan sensor to provide high quality images, so bandwidths greater than 100 Hz may be Is necessary. The control characteristics of the voice coil are known, and the voice coil design provides the required response and bandwidth to obtain high quality data from the linear scan sensor. However, the voice coil may cause the sensor to fall into the panel when energy is removed. This disadvantage can be overcome by preloading the moving coil to raise it in the state of removing energy, but the coil must continuously supply energy to counteract this preload, which in turn will cause undesirable hot air. Was injected into the system. In addition, the voice coil is difficult to control when first engaging the panel because there is no known electronic sensor to guide the voice coil to securely engage the panel.

According to an embodiment of the invention, a flight control device includes a pneumatic sensor and a voice coil. 8A and 8B are perspective and cross-sectional views of a flight control device 800 in accordance with an embodiment of the present invention. The flight control device 800 includes the pneumatic sensor 710 and a voice coil 812 in the illustration. The pneumatic sensor 710 causes the link member 706 edge member 806 to pivot and move the sensor fixing rod 808 and the linear scan sensor 240 in the Z-axis direction. The voice coil 812 surrounds the fixed rod 808 in the embodiment shown in Figures 8A and 8B. A preload spring 810 can be provided. Since the pneumatic sensor/actuator can accurately sense and follow the contour of the panel independently of the panel surface at a distance greater than 30 microns and provide a rigid platform, the pneumatic sensor/actuator can be slightly lower The panel is securely engaged with a predetermined fixed point of the flying height of the linear scanning sensor. Once the panel is engaged, the voice coil will activate and then raise the linear scan sensor an additional distance to the required flying height of the linear scan sensor and receive all flight functions. When the linear scan sensor is raised above the fixed point of the pneumatic sensor/actuator, the pressure in the actuator will drop and automatically disengage from the flight function. Once the voice coil actuator is engaged, the flight control device will operate at the desired bandwidth to achieve a high quality image. In the case of a voice coil failure (for example, due to a power supply interruption, a sensor failure, or an electronic component failure), the linear scanning sensor will collapse toward the panel and pressure will accumulate in the pneumatic actuator, and the pneumatic The actuator will automatically re-engage the linear scan sensor and receive the flight function. Therefore, the linear scan sensor is securely attached to the pneumatic sensor/actuator fixed point.

In some embodiments, a flight control device having a pneumatic sensor and a voice coil also includes a feedback controller. Since the pneumatic sensor can accurately follow the contour regardless of surface characteristics (such as conductivity, reflectivity), an electronic sensor such as the optical displacement sensor 820 or the height sensor circuit embedded in the linear scanning sensor itself can be used. Detect changes in flying height. The output signal of the electronic sensor can be fed to the voice coil for adjusting the flying height, thereby completing the servo feedback coil. To ensure complete coverage of the panel (with or without circuitry), in one embodiment, an optical sensor can be used to maintain flight height. In another embodiment, a height sensor based on an embedded capacitor can be used. In other embodiments, a combination of optical sensing and capacitive sensing can be used to sense the height and provide a feedback signal.

Setting and maintaining the flying height of the scanning sensor can be achieved by using piezoelectric actuation. The performance and control characteristics of piezoelectric stacks are known, and piezoelectric actuators can provide the desired response and bandwidth under ideal conditions to obtain data from the linear scan sensor. However, the physical size of the piezoelectric actuator is quite large compared to its stroke. Therefore, a relatively large piezoelectric stack will be required to provide the range of motion required for the linear scan sensor. For very long linear scan sensors, say 30 or 40 shorter units that are joined and aligned to span the overall width of the flat panel, the support structure will need to be particularly solid and may be bulky and heavy.

In accordance with another embodiment of the present invention, a flight control device includes a pneumatic inductor and a piezoelectric stack. Figure 9 is a perspective view of a flight control device 900 in accordance with another embodiment of the present invention. The embodiment 900 of the flight control device includes two pneumatic sensors 710 in the drawing, each of the pneumatic sensors 710 having a corresponding piezoelectric actuator 902 and a load coupled to one end of the linear scanning sensor 240. Support rod 904. The piezoelectric actuator 902 is coupled to its individual pneumatic sensor 710, thereby substantially reducing the desired range of motion. Located at each end of the linear scanning sensor assembly is a pneumatic sensor 714 and an optional optical displacement sensor. Alternatively, the linear scan sensor can have its own embedded height sensing circuit. The flight control device 900 includes a plurality of curved portions to limit movement on the Z-axis. The pneumatic sensor/actuator can accurately sense and independently follow the contour of the panel at the desired flying height and provide a rigid, stable platform. This embodiment 900 of the flight control device achieves the required response time and bandwidth to ensure that the linear scan sensor can obtain high quality images. The overall kit can be sufficiently compact and the scanning sensor array can be housed in a support beam that is both sized and cost effective.

In some embodiments, a flight control device having a pneumatic sensor and a piezoelectric stack includes a feedback controller. Since the pneumatic sensor can accurately follow the contour without considering surface characteristics (such as conductivity and reflectivity), such as an optical displacement sensor 906 or a height sensing circuit embedded in the linear scanning sensor itself The sensor can be used to detect changes in flying height. The electronic sensor output signal can then be fed to the piezoelectric actuator that adjusts the flying height to complete the servo feedback loop. To ensure complete coverage of the panel (with or without circuitry), in one embodiment, an optional sensor can be used alone to maintain the flying height. In another embodiment, an optical sensor having a height sensor based on an embedded capacitor can be used. In yet another embodiment, a combination of optical sensing and capacitive sensing can be used to sense the height and provide a feedback signal.

The flat panel must be accurately aligned relative to the linear scan sensor, typically within at least ±50 microradians (rotation) and at least ±175 micrometers (translation). The repeatability of the automatic control device for loading the TFT glass on the spacer in the X and Y directions is usually ± 2 mm. A setting requirement of ±5 mm allows the glass to slide as it moves while the glass is placed on the steam pad above the pad. The typical maximum angular displacement of the automatic control device can be calculated as follows: Θ _max = sin ^-1 (10/3200), or 3 milliradians. In order to meet the typical requirements of rotational or linear alignment, the glass alignment method must be able to rotationally correct the glass sheet from at least 3 milliradians to 50 milliradians and linearly correct it from, say, 5 mm. It is 0.35 mm.

The glass plate is relatively large (a few meters on one side) but relatively thin (0.5 mm to 1 mm). One method of aligning the panels is to use a brush as shown in Figure 10 to advance the edge of the panel to the panel, as is common with previous generations of glass panels. The brush member can include a swivel arm 1004 that rotates about an axis 1020, and a peg 1006 that extends at the same height as the top surface of the glass sheet 10 or slightly above the top surface of the glass sheet 10. The action of the brush member can be pneumatically driven or transmitted through a motor (not shown). A fixed alignment plug 1008 can be provided to ensure that the glass does not move beyond the extent of the brush member, which is typically located at the four edges of the glass. To avoid panel breakage, the side forces from the brush may need to be applied gently, and thus may require slow movement to complete the alignment of the panel, thus spending more time than allowed by the need for the crop. However, the action of the brush member can be controlled by the use of a servo motor to drive the brush member and have the ability to detect and feed back torque, or through a visual feedback member as described below.

Another method of using a brush to advance or stimulate the edge of the panel is to grasp one of the flat surfaces of the panel to move the panel. The top surface of the panel contains TFT circuitry or other structures or topography that are unsuitable for testing or inspection, and the bottom surface of the panel is physically accessible. The means for grasping the bottom surface of the panel must pass through the support block. In general, the grip is achieved by using a vacuum gasket to reduce the risk of adding contaminants to the substrate under test. There are many ways of arranging these penetrating pad holders for aligning the panel in a rotational and linear manner, as disclosed in U.S. Patent Application Serial No. 11/389,556. In an embodiment, the two grips are placed on a pair of corner lines. In another embodiment, as shown in Fig. 11, the four grips are arranged in a rectangular pattern. In Fig. 11, "M" stands for "primary" or drive unit, and "S" stands for "affiliated" or driven unit.

The penetrating pad holder or the brush aligning method can be used with a linear array sensor as disclosed in U.S. Patent Application Serial No. 11/468,206, which is incorporated herein by reference. Feedback is provided to achieve alignment of the grip. Figure 11A illustrates the possible locations of the three linear array sensors 1110. The linear array sensor can have a pixel pitch of approximately 62.5 microns, so if the resolution of the sensor is ±1 pixel, a translation resolution of 125 microns and a rotational resolution of 37.5 microradians are feasible. Therefore, the edge detector linear array sensor provides sufficient feedback to the penetrating pad holder assembly and meets the desired rotational and translation alignment specifications.

The penetrating pad holder assembly or the brush alignment method can also be used with the same development system to feed back the position and alignment information of the panel. As shown in FIG. 11B, the TFT glass substrate has alignment reference marks 1202 etched at respective corners and corners of the respective panels. The glass substrate reference mark can be detected by a development system having a sufficient field of view to detect the action of the panel. Two developing sensors can be placed at opposite corners of the glass to measure translation and rotation feedback errors of the grip control system.

Electrical signals are often applied to a panel under test through a probe head. The probe head is lowered to contact the panel, typically at one end or one side of the panel, and an electrical test signal is applied while the test or sensor head is stepping or scanning on the same panel. Since the probe pad on the panel is relatively close to the active area, the test head and the probe head cannot cross during the test. The probe head must physically contact the pad on the panel and the test head must be in close proximity but not in contact with the active area of the panel. The distance from the active region to the probe pad can be as short as 5 mm. One known solution uses a cantilever beam disposed on the probe head to allow the probe to physically contact the liner while maintaining the rigidity and volume portion of the probe rod away from physical interference. In some cases, the test head may bounce above a probe beam to move to the next position, or alternatively, the probe beam may move out of the aisle as the test head is moved and then return to the detection position. .

The overall throughput of the panel in this test system must be as high as possible. In the case where the test head and the probe head can operate together without collision, the overall throughput is usually impacted by the limited number of times required to move each test head and probe head into the test position. This sorting time is frequent and not popular for production machines. Therefore, the close combination between the sensor head and the probe head, the reliable contact requirement of the probe head with the panel to be tested, and the high throughput requirement of the panel test are intended to be overcome by the continuous scanning system of the present invention. challenge.

The step-and-spin sensor/test head is located at a location to collect a 2D image and step to the next position, while the continuous scan linear sensor/test head needs to be compatible with continuous scanning. For a continuous scanning system, raising the test head and moving it over the probe will interrupt the normal testing process of the machine and cause a loss of time. Optionally, if the linear test sensor continues to move and the probe head is briefly raised and removed from the path of the scan head, the panel will lose the drive signal and the test data will not be collected during the period of time. .

The present invention overcomes many of the limitations associated with physical design and throughput encountered with a single pole performing the same task. The present invention provides a different sequence of operations and uses a plurality of lifting gantry each carrying a different probe bar or sensing head, although the exemplary embodiments of Figures 12 and 13 show the use of two separately loaded probe bars 260, The lifting platform 204, 210 of the 250, and a lifting platform 202 carrying the sensing head 240. In Fig. 13, the position of the gantry 202 is shown to have been moved relative to the gantry 204, 210 in Fig. 12. Referring also to Figures 2, 13 and 14, the lifting gantry 204, 210 extends across the width of the system and along the rails 232, 234, and the linear sensing head 202 also spans the width of the system and extends along the rail 230. . The glass substrate 10 has a panel 1300.

Figure 14 is a flow diagram of the steps for operating the probe bars 260, 250 and the inductive head 240. At the beginning 1402, the internal feed probe bar (PBI) 210 is not connected to the ionization 10, and the external feed probe bar (PBO) 204 is located at the outer feed end of the first row of the panel 1300. . The PBO is lowered onto the panel (step 1404) and an electrical drive is applied (step 1406). The linear sensing head 202 begins scanning the first row of panels (step 1408). When the linear sensing head is sufficiently far from the PBI 210, the PBI moves into position and is lowered to the panel (steps 1410 and 1412). During the reorganization time of the data collection, the responsibility for the application of the drive signal is transferred from the PBO to the PBI (step 1414). The linear sensing head 202 continues to scan during this transition. The PBO is separated from the panel and moves toward the outer feed end of the next panel in the outer feed direction and descends and engages to the next panel (steps 1416 to 1420). The linear sensing head 202 continues to scan during this PBO activity. The responsibility of the drive signal is switched from the PBI to the PBO as the linear sensor head reaches the next panel (step 1422). The linear sensor head continues to the next panel, which is now powered by the PBO. The PBI is raised and moved to its next position (steps 1424 to 1426), and the exchange procedure between the PBO and the PBI continues until the entire glass sheet is scanned. When the processing of the board is completed, the PBO and PBI are each raised to leave the board, and then the PBO, PBI and the linear sensing head are each moved to their respective safe positions to enable the board to be unloaded (steps 1430 to 1434). .

Successful execution of the sequence in Figure 14 requires that the panel be designed with redundant shorting bar pads to allow the entire panel to be driven by internal feed or the external feed side pads. In addition, the design of the system requires that each of the probe bars (heads) can drive the pattern across the panel and drive the electronic support for dynamic exchange of control between the two probe heads. This control exchange can usually be completed during the refreshing of the panel when no measurements are performed.

The sequence and configuration of the probe rods and sensing/test heads above allows continuous scanning testing through a test signal that is driven to the panel at any time. In the entire panel, each of the probe heads sequentially delivers the panel drive to the other probe head. This allows the scan test head to have maximum throughput because the head never has to wait for the probe head to reposition.

The present invention also provides placement flexibility of the liner relative to the active region of the panel. Since the sensing/testing head is not in close proximity to the driving probe head, the panel has a relatively large area near the edge of the row, so that it can contain the probe pad without affecting physical packaging or throughput. .

A hardware embodiment that supports the probe bar and linear sensing/test head sequence in the continuous scanning system described above can include three lifting gantry, such as 202, 204, and 210 shown in Figures 2 and 15. The front lifting platform 204 carries the front probe bar 260, the intermediate lifting platform 202 carries the linear sensing/test head developing device 240, and the rear lifting platform 210 carries the rear probe bar 250. In one embodiment, each of the lifting gantry has an associated magnet track, also referred to herein as a railing, such as 230, 232, and 234 as shown in FIG. 2, and a code ruler. In another embodiment 1500 as shown in Fig. 15, all of the lifting platforms 204, 202 and 210 share the same magnet track 1510 and code ruler to save cost. In the embodiment illustrated in Figure 15, the front and rear of the platform have a slightly greater length to park the gantry during loading and unloading of the panel. The configuration in Figure 15 is suitable for conveyor loading and unloading operations in linear applications.

The present invention includes a gantry beam for use with the linear inductor that has sufficient rigidity and minimal sagging. The width of the beam (in the direction of the X-axis) is determined by the distance required for the automatic control device to clear the glass substrate and clear the probe rod axis during loading and unloading operations of the lifting frame end.

To achieve the shortest system length in the Y-axis direction and thus the minimum footprint, and still allow the automatic control arm actuator to be placed and removed from the spacer, the sensor lifting gantry and/or the probe The needle bar lifting frame is made to move in the Z-axis direction. The present invention provides a sink probe rod, which is shown in Figure 2, and Figures 16A and 16B are shown in more detail. Thus, the probe bars 250 and 210 are designed to advance toward the front or back of the system 200 and then descend to the spacer 206 and the glass 10 in the Z-axis direction as needed. In particular, the probe bars 250 and 260 can be lowered to allow the sensor gantry 202 to continue to advance to cover the entire block and to be parked directly above the probe bar axis.

Figure 16A is a side elevational view of a portion of the system 200 showing the sinker probe bar in an up position relative to the pad 206 and at the same level as the sensor gantry. Figure 16B is a top plan view of system 200 corresponding to the side view of Figure 16A. Figure 16C is a side elevational view of a portion of the system 200 showing the sinker probe bar in a downward position relative to the pad 206 and the sensor gantry frame passing over the probe bar. Figure 16D is a top view of system 200 corresponding to the side view in Figure 16C.

Referring to Figures 16A and 16C, the continuous linear scanning system of the present invention includes two cylinders stacked on each other at the ends of the probe bar lifting gantry. The upper cylinder 222 located in the sinking probe bar has a small stroke and moves up and down to rub or contact the pad on the glass substrate to align the panel for defect detection. The lower cylinder 220 has an extended stroke that moves the probe bar 260 up and down, and in particular can be moved below the spacer 206 to allow the glass 10 to be brought into and out of the system. (not shown) passes above the front probe rod. Thus the cylinder can move and park the probe bars 260 and 250 to avoid their shoulders, thereby resulting in the shortest length of the foot in the Y-axis direction.

The external dimensions of the tenth generation of continuous scanning systems should be approximately 4 by 4 meters. This footprint exceeds the maximum size of the container in the cargo bay that can be fitted into the largest aircraft such as the Boeing 747. Therefore, in order to match the container, the lifting platform foot must be divided into at least two parts. One of the embodiments is illustrated in Figure 17. In this example, the front portion may include the lower frame and base 208, the third spacer 206, the front probe bar lifting gantry 204, and the inductor lifting gantry 202. The rear portion may include the lower frame and base portion 208, the third spacer 206, and the rear probe bar lifting platform 210. The two sections may include registration pins and holes to speed up the alignment and alignment of the components when assembled at the client. These two modules can be fitted into the cargo space of the Boeing 747 freighter. Figure 17 illustrates a granite based system. The steel frame-based system can also be divided into module parts for shipping purposes.

Front surface illumination is provided to detect defects in amorphous germanium and other photosensitive panels. Alternatively, the spacer may be made of a transparent material such as glass, and illumination may be provided through the rear surface. In either case, the present invention can be configured such that it can observe and/or test photosensitive defects, such as amorphous germanium that will change its impedance when exposed to light (short wavelengths such as 470 nm), as well as Applying a drive voltage when the light is extinguished will result in a timing of the contrast signal.

The sensor carrying gantry can have a detection camera such as a defect inspection camera (DRC), an optical camera (OCR), and/or an alignment optical system camera (AOS), and thus become an integrated optical Non-contact scanning test system for linear scanning capacitive sensor assembly with detection capability. Optionally, the scanning sensor can be an optical sensor having a particular resolution, and the additional detection camera can have a higher resolution and be used for viewing purposes. Another embodiment can combine the non-contact linear capacitive sensor with a linear optical sensor on the same or different lifting gantry of the scanning system.

The above-described embodiments of the present invention are illustrative and not restrictive. Various alternatives and equivalents are possible. The invention is applicable to high throughput testing of TFT/LCD panels, OLED based TFT panels, solar panel panels and any other flat media. Other additions, reductions, or modifications are apparent to the teachings of this specification and are considered to be within the scope of the appended claims.

10,1300. . . Glass plate, panel

104,202,204,210. . . Lifting platform

15. . . Modulator

200. . . system

25. . . Air gap

206. . . Pad surface

30. . . Flat panel electrode

208. . . platform

35. . . camera

204. . . External feed probe

45. . . Liquid crystal material

210. . . Internal feed probe

50. . . Flat glass

220,222. . . cylinder

102. . . Substrate

230,232,234. . . railing

240,302. . . Linear sensor

710. . . Pneumatic actuator

250,260. . . Probe rod

712. . . Curved part

304. . . sensor

714. . . Distance sensor tube

306. . . Sensor array

716. . . Connecting the trachea

308. . . Two-dimensional array

718. . . Compressed preload spring

310. . . Linear array

800,900. . . Flight control device

320. . . Control distance

812. . . Voice coil

320. . . Fixed height

806. . . element

402. . . Triangle plate

808. . . Sensor rod

404. . . Support point

810. . . Preloaded spring

406. . . Rectangular brick

820. . . Optical displacement sensor

410. . . seam

902. . . Piezoelectric actuator

422. . . Uplift pattern

904. . . Load support rod

602. . . Beam column

906. . . Optical displacement sensor

600. . . Pad

1004. . . Rotating arm

604,606,608. . . aisle

1006,1008. . . bolt

700. . . Flight control device

1110. . . Linear array sensor

702. . . Air inlet

1020. . . axis

704. . . Needle valve

1202. . . Alignment reference mark

706. . . Link

1510. . . Magnet track

708. . . Curved support rod

Figure 1A shows a floating modulator located above a patterned glass plate, as is known in the art; Figure 1B shows that the floating modulator is located near the patterned glass plate in Figure 1A to perform the test, As is known in the art; FIG. 1C shows a conventional system for electrical testing of flat panels; and FIG. 2 shows a system with continuous linear scanning to test panels according to an embodiment of the invention; 1 is a side view of a linear scanning sensor according to an embodiment of the present invention; FIG. 3B is a side view of a linear scanning sensor according to another embodiment of the present invention; FIG. 3C is a side view showing a side view A linear sensor array including a single line sensor array according to an embodiment of the invention; FIG. 3D is a side view showing a linear sensor including a multi-line sensor array forming a two-dimensional sensor array according to another embodiment of the present invention Array; Figure 4 shows the layout of a block using triangular bricks; Figures 5A through 5C show various illustrations of a block using triangular bricks; Figure 6 shows a block using a plurality of rigid beams; And 7B map A perspective view of a diaphragm/pneumatic flight control device, wherein the diaphragm/pneumatic flight control device is used in a continuous linear scanning system in accordance with an embodiment of the present invention in FIG. 2; and FIG. 7C is in FIGS. 7A and 7B. A cross-sectional view of a diaphragm/pneumatic flight control device; FIGS. 8A and 8B are perspective and cross-sectional views of a composite pneumatic/voice coil flight control device in accordance with an embodiment of the present invention; and FIG. 9 is another perspective view of the present invention. A perspective view of a hybrid pneumatic/piezoelectric actuator flight control device of an embodiment; FIG. 10 shows a brush device; and FIG. 11A shows a linear array sensor for reading and providing a feedback position for alignment The top view of the spacer penetrating the grip; Figure 11B is a top view of the spacer having a fiducial mark for a visualization system to read and provide a feedback position for alignment of the spacer; 12 and 13 2 is a top view of the probe bar and the sensor head of the continuous linear scanning system according to an embodiment of the invention; FIG. 14 is a flow chart illustrating the continuous application of the test signal to the second The continuous linear scanning system test level in the figure Steps of the panel; Figure 15 is a simplified perspective view illustrating a scanning system including three lifting gantry sharing the same encoder and track; FIGS. 16A and 16B are cross-sectional and top views showing the bearing The lifting gantry of the sink probe is located at an upward position and at the same level as the gantry carrying the linear sensor array; the 16C and 16D are cross-sectional and top views showing the bearing The lifting gantry of the sinking probe bar is located at a lower position than the lifting gantry carrying the linear sensor array; and FIG. 17 shows an exemplary multi-piece lifting gantry Foot platform.

10. . . Glass plate, panel

200. . . system

202,204,210. . . Lifting platform

206. . . Pad surface

208. . . platform

220,222. . . cylinder

230,232,234. . . railing

240. . . Linear sensor

250,260. . . Probe rod

Claims (22)

A system adapted to perform continuous full linear scanning of a flat medium having a plurality of pixels, the system comprising: a chuck adapted to support the flat medium; a first lifting gantry, the first lifting gantry Included is a linear array of at least one non-contact sensor that spans the width of the flat media and is adapted to move across the overall length of the flat media; a second lifting gantry, the second lifting gantry comprising a a first probe head spanning the width of the flat medium and adapted to apply a first electrical signal to the flat medium, the first probe head further adapted to be on the first lifting gantry Moving in a direction substantially perpendicular to a surface of the flat medium during operation; and a third lifting gantry comprising a second probe head spanning the second probe head Width of the flat medium and adapted to apply a second electrical signal to the flat medium, the second probe head further adapted to be substantially perpendicular to a surface of the flat medium when the first lifting gantry is in motion The direction of movement. The system of claim 1, further comprising a flight control device comprising: an actuator; and a feedback control circuit operatively associated with the actuator and adapted to sense the contactless The distance between the linear array of the device and the flat medium is maintained within a predetermined range. The system of claim 2, wherein the actuator comprises at least A pneumatic actuator. The system of claim 3, wherein the actuator further comprises at least one voice coil. The system of claim 3, wherein the actuator further comprises at least one piezoelectric actuator. The system of claim 2, wherein the feedback control circuit is integrated with the linear array of the at least one non-contact sensor. The system of claim 1, further comprising a control circuit adapted to control movement of the first and second lifting gantry to implement the flat media when the test signal is continuously applied to the flat media Continuous scanning. The system of claim 1, wherein the at least one non-contact sensor linear array comprises an assembly of mutually coupled and aligned linear inductors to span the full width of the flat medium. The system of claim 1, wherein the first lifting gantry further comprises a linear array of second non-contact sensors across the width of the flat medium. The system of claim 9, wherein the second non-contact sensor linear array comprises an assembly of mutually coupled and aligned linear inductors to span the full width of the flat medium. The system of claim 1, further comprising: a first cylinder having a first stroke and adapted to move a plurality of probes on the first probe head to make contact or non-contact a plurality of pads on the flat media; a second cylinder having a second stroke greater than the first stroke and adapted to move the first probe head below a top surface of the chuck. A method of performing continuous full linear scanning of a flat medium having a plurality of pixels, the method comprising: supporting the flat medium during the full linear scan; causing a first lifting gantry to move across an overall length of the flat medium, The first gantry includes at least one linear array of non-contact sensors across the width of the flat medium; causing a second gantry including a first probe head while the first gantry is in motion Moving along a direction substantially perpendicular to a surface of the flat medium, the first probe head spanning the width of the flat medium and adapted to apply a first electrical signal to the flat medium; and causing a second probe to be included The third lifting platform of the head moves in a direction substantially perpendicular to a surface of the flat medium while the first lifting platform is in motion, the second probe head spanning the width of the flat medium and is adapted to A first electrical signal is applied to the flat media. The method of claim 12, further comprising: maintaining a distance between the linear array of non-contact sensors and the flat medium within a predetermined range. The method of claim 13, further comprising: using at least an actuator to maintain the distance between the linear array of non-contact sensors and the flat medium within a predetermined range. For example, the method of claim 14 of the patent scope further includes: At least one actuator and at least one voice coil are used to maintain the distance between the linear array of non-contact sensors and the flat media within a predetermined range. The method of claim 14, further comprising: using at least an actuator and at least one piezoelectric device to maintain a distance between the linear array of non-contact sensors and the flat medium within a predetermined range. The method of claim 13, further comprising: integrating a feedback control circuit with the linear array of the at least one non-contact inductor, the feedback control circuit being adapted to linearize the non-contact inductor with the flat The distance between the media is maintained within the preset range. The method of claim 12, further comprising: controlling movement of the first and second lifting gantry to effect continuous scanning of the flat medium when a test signal is continuously applied to the flat medium. The method of claim 12, wherein the at least one non-contact sensor linear array comprises an assembly of mutually coupled and aligned linear inductors to span the full width of the flat medium. The method of claim 12, wherein the first lifting gantry further comprises a linear array of second non-contact sensors across the width of the flat medium. The method of claim 12, wherein the second non-contact sensor linear array comprises one of linear sensors coupled and aligned with each other The assembly is designed to span the full width of the flat media. The method of claim 12, further comprising: moving a plurality of probes on the first probe head to or not contact a plurality of pads on the flat medium; and The needle moves below the top surface of the chuck.