JP3180834U - Automatic processing of electro-optic transducers used in LCD test equipment. - Google Patents

Abstract

An LCD test system with improved quality and improved safety by automated processing of electro-optic transducer elements in the system.
An AME 500 overcomes access problems by automatically replacing electro-optic transducer elements on an array test system. In addition, it includes a number of replacement pods located on one of the gantry stages that carry signals that drive the panel under inspection. These gantry stages, referred to as probe bars (PB), are configured to carry a probe contact assembly that provides an electrical drive signal to the panel under test. In one embodiment, there are two PBs per array checker system. The modulator replacement pod 520 is disposed on the rear PB 530 and is disposed at the rear end of the movement range.
[Selection] Figure 5

Description

Description of related applications

This application is filed on Jan. 8, 2010, 35 of US Provisional Application No. 61 / 293,579, entitled “Automatic Processing of Electro-Optic Transducers Used in LCD Test Equipment”.
Enjoy the benefits of USC 119 (e).

  The present invention relates to an apparatus for electrically inspecting thin film transistor (TFT) arrays used in liquid crystal (LC) or organic light emitting diode (OLED) displays.

  When manufacturing a flat panel liquid crystal display, various inspection stages are performed to identify defects in the manufactured display. One type of inspection is an electrical inspection of thin film transistor arrays used in displays. An example of such an array tester is the Array Checker AC5080 commercially available from Photon Dynamics, Inc., an Orbotech company in San Jose, California.

  Array testers (or “array checkers” or “AC”) are described, for example, in US Pat. Nos. 4,983,911, 5,097,201, and 5,124,635. The failure of the LC display is identified through the use of such a “Voltage Imaging®” test apparatus and method. Since the LC display consists of an array of pixels, when the LC display is electrically driven, the pixels associated with the defect may behave differently from normal pixels, and thus the difference. Is detected using a voltage imaging sensor.

Many of these voltage imaging sensors rely on electro-optic transducers, such as LC materials such as nematic curve aligned phase or twisted nematic molecules, Pockels crystals such as LiTaO ₃ and LiNbO _3, etc. Based on the electric birefringent crystal. In the case of the Orbotech array checker, the electro-optic material is affixed to a glass carrier weighing approximately 5 pounds and sandwiched between the transparent electrode and the reflective film. The resulting assembly is referred to as a “modulator” and is shown in FIG. Referring to FIG. 1B, the modulator 10 is installed in a modulator air bearing mount 20 attached to an optical lens assembly 40 covered by an imaging sensor 60 such as a CCD camera. A light emitter 80 is attached to the camera 60. The constructed assembly is referred to as a voltage image light system (VIOS) 100 as shown in FIG.

  2A and 2B are a front view and a top view of the modulator air bearing mount 20, respectively. Referring to FIG. 2A, during testing, the modulator is placed a small distance away from the TFT glass panel 210 under test, and a substantial gap between the electro-optic transducer (modulator) and the pixel electrode on the panel. Ensure capacitive coupling. This distance is usually 25-80 μm and is maintained by air bearings using, for example, three injectors 220 with adjustable flow. Modulator sense feedback analog signal 225 measures the bias voltage applied to the transparent electrode of the electro-optic material. The modulator mount includes a set of clamps 230 that grab, position or release the modulator. The clamp is configured to operate pneumatically to secure the modulator to the inspection head. FIGS. 2A and 2B show the modulator housing 235 in the float plate 240. The float plate is fixed to the modulator mount 250. In addition, each modulator may have its own RFID tag 260. The RFID tag 260 is detected by the RFID reader 270 of the inspection head.

Access to a modulator or similar electro-optic transducer assembly in an array test system is required for a number of reasons as follows.
(1) Removal and installation of electro-optic transducer elements (2) Removal of particles and other debris that can interfere with the test process and damage the panel under test, as well as optimization of transducer element life Cleaning the sensing surface (panel side) of the electro-optic transducer element (3) Adjusting the air bearing settings to ensure that the modulator is above the panel under test and will fly at the correct height

  Typically, this adjustment is made every time the modulator is changed or when adjustments are needed to maintain proper signal strength and uniformity.

The above process generally involves intensive manual processing of electro-optic elements and thus requires physical access to the inspection head inside the system. However, as the size of the glass on which the display is assembled increases, the size of the equipment used in the assembly process also increases, including the test system. Also, the number of inspection heads increases as the glass size increases to maintain sufficient throughput. For example, a Gen5 (1100 mm × 1300 mm) AC system uses a single VIOS, while Gen10 (2850 mm × 3050 mm and above) uses four VIOS. The increase in system size and number of heads makes direct access to the electro-optic transducer significantly difficult, as shown in FIG. FIG. 3 is a schematic diagram of the array test system 300. For systems that process glass substrates larger than Gen8, the operator can connect all VIOS from the side of the system.
100 It is practically impossible to safely reach the inspection head (three or more). This is especially true for systems that use a gantry-style architecture (such as the Orbotech Gen8 array checker). The reason is that the system normally uses a riser 310 (usually made of granite) where the main gantry beam 320 flies on either side in the longitudinal direction of the glass. Access from the front of the system is not possible on that side due to the presence of the glass loader robot chamber 330. The back of the system is the only place where an operator can safely stand inside the enclosure of the environmental chamber 340 that encloses the tool (if the stage is properly disabled by the interlock system). . However, even here, a subsystem such as the probe configuration station 360 or electronics cabinet 350 (used to configure a subsystem that supplies electrical drive signals to the panel under test for the layout to be inspected). Due to the presence, it is difficult to reach the inspection head. In the split access system, backward access is impossible, but side access is easy because there is no rise in system length.

  Another problem with manual handling of electro-optic transducer elements and mounts on which they are installed is the issue of safety and damage. As the need for operators to work in close proximity to the inspection head increases, the likelihood of failure due to collisions with moving parts in the system increases. It should be noted that the VIOS head in the AC system has a moving mass of approximately 200 pounds and develops a 1.7 G acceleration and a speedup of over 1 m / s. The operator may also drop the electro-optic transducer element, tiled chuck 370, or other parts of the system onto the plate under inspection, causing damage to the plate, transducer element, or system.

  FIG. 4 shows a flowchart of a modulator replacement procedure 400, known in the prior art. As shown in FIG. 4, replacing a modulator in an AC system (or similarly installing a new modulator) selects the VIOS test head (405) and initiates a replacement sequence from the control computer graphical user interface (410). This is done by moving (415) the selected VIOS head that is to be exchanged for the accessible area. Subsequently, if something is present, the mechanical switch operated by the foot is pushed by the second operator to open or release the clamp (element 230 in FIGS. 2A and 2B). In the meantime (425), the first operator places (420) a receptacle (or electro-optic transducer or simply referred to herein as a transducer) under the modulator to be removed. The first operator receives a modulator that falls into the receptacle (430). The second operator remotely opens the foot switch and thus closes the modulator clamp (435). Next, the receptacle with the new modulator is placed under the empty modulator mount by the first operator (440). Thereafter, the foot switch is pressed again by the second operator by remote operation to open the modulator clamp (445). The first operator then manually loads the modulator onto the mount (450). The second operator then opens the footswitch, which causes the clamp to be closed remotely (455) and a new modulator is incorporated into the mount. The test test is then resumed via the GUI if the progress is safe (460).

In an array test system that relies on an electro-optic transducer, the transducer is maintained at a short and uniform distance above the panel under test (depending on the transducer type and mode of operation, eg, approximately 50 μm) and touched. It is necessary to ensure capacitive coupling between the two while preventing down.
This is ensured by means of an air bearing with a plurality of air injectors (element 220 in FIGS. 2A and 2B) incorporated into the transducer element or mount that holds the transducer. In general, three injectors (located at the vertices of an equilateral triangle) are used because three points define a plane. The flow through each injector is individually controlled to raise or lower the modulator at that point (flow is increased) or lower (flow is reduced). In general, this adjustment is made when the inspection head is lowered (creates a gap) to the first part of the plate under test. In many cases, a signal detected by an image sensor is used for adjustment. For example, in conventional array checker systems, leveling is as close as possible to the desired raw detection signal at the gapping position, or to the target height value, by manually adjusting the flow at each injector individually. This is done by obtaining any desired difference between the signal recorded by the raised head and the I-bias signal. In previous generation array test systems, flow regulation at each air injector was performed using manually adjustable valves that control the pressure at each injector.

  According to one embodiment of the present invention, an LCD test system includes, in part, one or more inspection heads, one or more holders, a stage assembly, one or more electro-optic transducer elements, Including a clamp and a computer control system. The holder is configured to receive an electro-optic transducer element. The stage assembly is configured to hold the holder and is configured to move the electro-optic transducer element from the holder to the inspection head. The clamp is configured to secure the electro-optic transducer element to the inspection head.

  In an embodiment of the present invention, the stage assembly is further configured to transport the probe contact assembly. The holder can be adjusted in multiple directions, allowing adjustment of the surface of the electro-optic transducer element relative to the inspection head. The holder has vertical compliance and reduces residual misalignment between the inspection head and the electro-optic transducer element. The holder includes one or more alignment reference points. The camera placed on the inspection head looks at the alignment reference point and allows the holder to be aligned with the camera. The sensor is configured to verify the presence and proximity of electro-optic transducer elements in the holder and in the inspection head. The sensor is an optical proximity sensor or an RFID reader. The clamp may be a pneumatically operated clamp.

  In accordance with one embodiment of the present invention, an LCD test system includes, in part, an inspection head, at least one cleaning station, and a stage assembly configured to hold and move the cleaning station. including. The cleaning station is configured to receive and store the electro-optic transducer element.

  The cleaning station includes, in part, one or more nozzles that supply a first gas flow to the surface of the electro-optic transducer element to release and remove particles from the surface.

  In an embodiment of the present invention, the first gas in the gas flow consists of clean dry air or nitrogen, or is ionized to allow removal of particles attracted by electrostatic attraction. The cleaning station is configured in part to supply water and a plurality of jets and to supply air or a second gas to dry the electro-optic transducer after the water is supplied. A plurality of nozzles. The stage assembly is further configured to transport the probe contact assembly. The cleaning station can be adjusted in multiple directions, allowing adjustment of the surface of the electro-optic transducer element relative to the inspection head. The cleaning station has vertical compliance and reduces residual misalignment between the inspection head and the electro-optic transducer element. The cleaning station may include one or more alignment reference points in part. The inspection head partially includes a camera. The system includes one or more sensors configured to verify the presence and proximity of the electro-optic transducer element to the cleaning station prior to supply of the first gas.

  In one embodiment of the present invention, an LCD test system includes, in part, an electro-optic transducer element, one or more orifices disposed over the electro-optic transducer element for gas injection, and a gas And a computer configured to control flow and pressure. The gas flow is used to place the electro-optic transducer element within a known vertical distance from the panel under test.

  In an embodiment of the present invention, the LCD test system further includes a closed loop control system configured to automatically adjust the vertical distance until a target signal value is detected on the image sensor. Including. The inspection head is configured to hold the electro-optic transducer element of the LCD system. A plurality of fixed orifice flow control valves are connected to each of the orifices to control the gas flow and pressure. The solenoid valve is connected to the fixed orifice flow control valve and is configured to select one of the fixed orifice flow control valves.

  The first fixed orifice flow control valve includes in part an orifice that is narrower than the second fixed orifice flow control valve. Other embodiments include, in part, a check valve connected between each of the fixed orifice flow control valves and the orifice to prevent backflow. The solenoid valve first selects the first fixed orifice flow control valve and, if necessary, selects the second fixed orifice flow control valve.

(A) is a schematic diagram of a conventionally known modulator, and (B) is a schematic diagram of a conventionally known voltage imaging optical system (VIOS). (A) is a front view of a conventionally known modulator air bearing mount, and (B) is a top view of a conventionally known modulator air bearing. 1 is a schematic diagram of a conventionally known array test system that emphasizes access issues. FIG. It is a flowchart of a conventionally known modulator replacement procedure. 1 is a schematic view of automatic modulator replacement according to an embodiment of the present invention. FIG. BRIEF DESCRIPTION OF THE DRAWINGS (A) of the modulator replacement pad by one embodiment of this invention is a front view, (B) is a top view. 5 is a flowchart describing a sequence of automatic unloading of a modulator according to an embodiment of the present invention. It is a flowchart describing the sequence of the automatic loading of the modulator by one embodiment of this invention. (A) of the modulator cleaning station by one embodiment of this invention is a front view, (B) is a top view. 3 is a flowchart of a sequence used for automatic cleaning of a modulator according to an embodiment of the present invention. Fig. 2 shows a number of parts of remote air bear link control chemistry and automation control according to one embodiment of the present invention; Fig. 2 shows a number of parts of remote air bear link control chemistry and automation control according to one embodiment of the present invention;

  To facilitate access to inspection heads of large array test systems, such as Generation 7 inspection heads, and to prevent operator injury and damage to instruments, glass substrates and electro-optic transducer elements in array test systems In addition, embodiments of the present invention provide an automated process for electro-optic transducer elements in such systems. The automation process includes, in part, loading and unloading, cleaning, and air bearing adjustment by improving the accuracy and reproducibility of the adjustment as well as reducing the time required to make the adjustment. In order to achieve the above objectives, embodiments of the present invention, among other effects, are described in detail below as (i) an automatic modulator changer, (ii) an automatic modulator clean station, and (iii) ) Provide remote adjustment of modulator air bearing.

Automatic modulator replacement (AME)
FIG. 5 is a schematic diagram of an AME 500 according to an embodiment of the present invention. As described in detail below, among other effects, the AME 500 is similar to the safety and damage risks inherent in conventional systems by automatically replacing electro-optic transducer elements on the array test system. Overcoming the problem of access. To accomplish this, the AME 500 includes a number of replacement pods located on one of the gantry stages that carry signals that drive the panel under inspection. These gantry stages, referred to herein as probe bars (PB), are configured to carry a probe contact assembly that provides an electrical drive signal to the panel under test. In one embodiment, there are two PBs per array checker system. The modulator replacement pod 520 is disposed on the rear PB 530 and is disposed at the rear end of the movement range thereof. With this configuration, the modulator is placed or pulled into the replacement pod (or referred to herein as a holder) with minimal risk to the operator and instrument. The number of replacement pods depends on the number of inspection heads. In one embodiment, there is one replacement pod per head. In other embodiments, the number of replacement pods is less than the number of heads. In yet another embodiment, there are two exchange heads for three heads.

  FIGS. 6A and 6B are schematic views of a modulator replacement pod 520 according to an embodiment of the present invention. A modulator exchange pod 520 is shown having a receptor ring 610 configured to receive the modulator 10. In some embodiments, the replacement pod 520 includes a second modulator receptacle, holder, or case, such as a transport case 620 that receives the modulator to avoid contact with a person. The receptor ring 610 is located on the top of the adjustable base 630. The adjustable base 630 is adjusted within a sufficient range (for example, up to 250 μm) with 6 degrees of freedom and is in the same plane as each air bearing mount, where the modulator is placed. The final adjustment is locked by a leveling screw or bolt and a locking nut 640. In addition, the receptor ring has built-in vertical compliance by an O-ring 645 disposed between the ring 610 and the adjustable base 630, between the surface of the modulator in the pod and the surface of the modulator mount. Absorb or reduce residual misalignment. The receptacle ring has three locating or alignment pins 650, as shown, to accurately place the modulator inside the pod, or the modulator (or its receptacle holder 620) in the pod during the exchange process. To prevent lateral movement of the.

  In order to position the exchange rod relative to the inspection head (and thus the modulator is located in the exchange pod), an alignment reticle 660 (or referred to herein as an alignment reference point or mark) Mounted on the side. The alignment mark can be seen by an optical camera attached to the side of the inspection head. The exact X, Y and theta positions of the stages involved in the exchange (VIOS stage and rear PB gantry for AC systems) are between the center of the optical camera system and the modulator air bearing mount (ie, inspection optics) Can be adjusted by (known) offset and recorded reticle position.

  A number of sensors, like the inspection head, are placed in the replacement pod, allowing the replacement process to be monitored and avoiding collisions. In some embodiments of the present invention, three proximity sensors are used in contact with each pod. The first proximity sensor, referred to as modulator proximity sensor 670, detects the presence of the modulator in the receptor ring. The second proximity sensor, referred to as modulator presence sensor 680, detects the presence of the modulator as it is loaded (eg, from the modulator mount of the inspection head). The third proximity sensor, referred to as case sensor 690, detects the second modulator receptacle, holder or case on the replacement pod. Furthermore, if each modulator has its own RFID tag, the RFID reader of the inspection head is used to confirm the successful replacement of the modulator and track the modulator being replaced. The modulator detection feedback analog signal can also be used to confirm the successful replacement of the modulator.

  FIG. 7A is a flowchart 750 describing a sequence of automatic unloading of a modulator according to one embodiment of the present invention. The front PB (which does not carry the replacement pod) waits in front of the system (752). The main gantry transports the inspection head and is moved to a predetermined longitudinal (Y-) exchange position, for example, at the rear end of its movement range (754, which shortens the exchange time). The gantry is also maintained in its current position. The inspection head equipped with the modulator that needs to be replaced is mounted on the X / Z stage combo, and is raised to a predetermined lateral (X-) replacement position in the Z direction (756). These X positions should correspond to the X positions of the rear PB replacement pods. The Z position should correspond to the focus of the camera used to view the alignment mark, assuming there are no mechanical obstacles between the inspection head and the replacement pod. The rear PB carries the replacement pod and is moved below the main gantry (760). Note that the replacement pod should be empty, which can be confirmed using a proximity sensor (758). The alignment mark position is recorded (762). If the alignment mark positions do not fall within the field of view of the optical camera used to view them, a helical search routine can be used (764).

  Based on the recorded position, the Y direction of the back PB and the theta or Z position and the X position of the inspection head can be adjusted (766). The inspection head is lowered to the height of the replacement position (768). This can be determined by the presence sensor as described above (770). The modulator is released over the replacement pod (772). When the presence of the modulator in the pod is confirmed using the presence sensor (774), the inspection head is raised again (776), and then the rear PB reaches the rear end of its travel range. Moved in the Y direction. The operator can remove the modulator removed from the inspection head (778).

  In some embodiments, the modulator mount clamp used to grip and release the modulator is operated by a button located outside the environmental chamber where the tester is located.

  FIG. 7B is a flowchart 700 describing an automated loading sequence for a modulator according to one embodiment of the present invention. In the following, it will be assumed that the modulator has been unloaded from the inspection head, for example using the sequence shown in flowchart 750 above. Referring to FIG. 7B, automatic loading of the modulator is accomplished by first selecting the VIOS inspection head (702) and initiating (704) an automatic exchange sequence from the control computer's graphic user interface. The inspection head and rear PB axis are then moved to a predetermined location for load / unload access (similar to unloading step 1-3 above) (706). The operator installs and aligns the modulator with the receptacle into the corresponding replacement pod of the rear PB (708). The operator exits (710) the system enclosure and, if safe, continues the process sequence.

  The system then uses the sensor to automatically check for the presence of a modulator in the replacement pod (712). If the modulator is not present in the pod, the process sequence ends (732). If the modulator is detected inside the pod by the sensor, the rear PB moves down the main gantry at a predetermined exchange location (714). The system then automatically aligns the inspection head, main gantry, and rear PB (716) using the pod alignment mark and inspection head optical camera (similar to unloading step 4 above). If the automatic alignment fails, the process sequence ends (732). If the automatic alignment is successful, the inspection head is gradually lowered (718) to the replacement height (similar to unloading step 5 above). The system checks the proximity of the modulator (720) and uses the sensor to mount the modulator on the inspection head. If the proximity check fails (720), the process sequence ends (732). If the proximity check is successful, the operator remotely activates the modulator clamp on the modulator mount when the inspection head grips the modulator from the pod (722). In other embodiments, the system automatically operates a modulator clamp that grips the modulator from the pod without operator intervention.

  The system then uses the sensor (724) to automatically confirm that the modulator is properly clamped by the test head. If the clamp check fails (724). The process sequence ends (732). If the modulator is clamped successfully, the test head is raised (726). Next, the inspection head and the PB axis are moved to a predetermined location for load / unload access (728). The operator then enters the system enclosure and removes an empty receptacle from the rear PB gantry (730).

  The entire modulator exchange process is controlled by a computer. There are at least three main components for the control software, so-called movement control, alignment and user interface. The software movement control component ensures that the included axes are moved to the proper position for replacement in the correct sequence. The movement control also includes an interlock for preventing one axis from colliding with another axis. Software alignment control determines the offset of the alignment reticle with respect to the center of the field of view of the optical camera, and determines the correction of the stage position for replacement of the modulator. The software user interface component allows the user to safely operate separate stages (eg, movement, alignment, loading / unloading) of the exchange process for each head.

Automatic modulator cleaning station (AMCS)
Conventional cleaning of a modulator in an AC system includes removal of the modulator from the mount, cleaning with a solvent-absorbing light wipe, and repositioning to the original position.

In one embodiment of the present invention, AMCS enables safety and risk of damage inherent in current manual procedures by enabling an automated method of cleaning electro-optic transducer elements in an array test system. Overcome similar access problems. FIGS. 8A and 8B show a front view and a top view, respectively, of a modulator cleaning station 540 according to one embodiment of the present invention. The modulator cleaning station 800 includes a receptor ring 810 configured to receive the modulator 10 from the inspection head, and one or more nozzles 840 configured to blow ionized air or N ₂ continuously or intermittently. ,including. Ionized air or N ₂ releases particles present on the surface by electrostatic adsorption. Following the cleaning operation, the cleaning station is maintained at a negative pressure by a vacuum seal 820 disposed in the cleaning space 830 between the receptor ring and the modulator 10 to remove the appropriate particles released by ionization. Ionized air is supplied through an in-line ionizer and nozzle 840 mounted into the cleaning station. A vacuum is achieved through another orifice (not shown). Air (or N ₂ ) and evacuation are turned on and off by computer controlled solenoids 842 and 844, respectively. The direction of the cleaning gas flow 846 is indicated by a thick arrow in FIG. In addition, a wiper with a clean room cross roller can be installed in the AMCS to wipe the detection surface of the modulator. Alternatively, the modulator can be cleaned by deionized water supplied by a jet installed in the cleaning station, and then dried using clean dry air or nitrogen supplied by a nozzle in the same station (heated). Done.

  The cleaning station is similar to the modulator replacement pod. In one embodiment, the cleaning station includes an alignment pin 850, an alignment reference 860, and a proximity sensor 870. Some embodiments of the present invention include a multi-cleaning station 540 as shown in FIG. Some embodiments include the same number of cleaning stations and inspection heads. In some embodiments, the cleaning component that performs the cleaning operator is integrated into the modulator replacement pod. In another embodiment, the components used for cleaning are separated from the components used for modulator replacement and are mounted on the front probe bar (element 510 in FIG. 5).

  FIG. 9 is a flowchart 900 of a sequence used to automatically clean a modulator according to one embodiment of the present invention. As shown in FIG. 9, the modulator is cleaned by selecting a VIOS head to be cleaned (902) and starting an automatic cleaning sequence from the GUI of the control computer (904). The operator sequence of the cleaning process is similar to that of the replacement process.

  The rear PB does not carry the cleaning station and stays behind the system. The inspection head with the selected modulator is mounted on the X / Z stage combo of the main gantry and is further raised in the Z direction to a predetermined lateral (X-) “cleaning” position. These X positions correspond to the X positions of the cleaning pods on the front PB. Assuming there are no mechanical obstacles between the inspection head and the cleaning station, the Z position corresponds to the focus of the camera used to view the alignment mark. The main gantry moves above a predetermined “cleaning” position, ie, forward PB, or is maintained at the current position. The forward PB carries the replacement pod and moves (906) below the main gantry (if it is not already there) and the alignment mark position is recorded (if the light used to view the alignment mark). Spiral search routines are used when they are out of the camera's field of view). Based on the recorded position, the Y and theta positions of the front PB and the X position of the inspection head are adjusted during automatic alignment (908). If the automatic alignment fails, the process sequence ends (918). If the automatic alignment is successful, the inspection head is gradually lowered into the cleaning station (910). Next, the system checks the proximity of the modulator mounted at the cleaning station (912). This is determined by the presence sensor as described above. However, the modulator is not released. If the proximity check fails (912), the process sequence ends (918). If the proximity check is properly checked, the cleaning process begins (914). After cleaning has been performed, the inspection process is typically resumed (916).

  As in the case of replacement, the entire process is computer controlled, including the timing and operation of the air and evacuation involved in the cleaning.

Remote Adjustment of Modulator Air Bearing According to one embodiment of the present invention, the access issues as well as the safety and risk of damage inherent in current manual procedures are two fixed orifice flow control valves, one of which is By using one with a narrow orifice, the other with a wide orifice, this is overcome by allowing remote control over the flow at each injector. At each injector, the orifice selection is made via a dedicated solenoid valve upstream. The range of air flow in each injector channel can be increased compared to existing designs and can be switched remotely by computer control between the high and low flow ranges flowing through the corresponding wide and narrow orifices. In one embodiment of the present invention, remote air bearing air control and automation control are shown in FIGS. 10A and 10B, respectively. The height of the modulator above the panel under test can be precisely adjusted by controlling the air pressure and orifice by software. This adjustment is performed by a remote operation by an operator, or can be automatically performed without an operator. The algorithm repeatedly increases or decreases the air bearing pressure until the evacuated target is met. The algorithm first selects low air flow through the narrow orifice to determine if it meets the evacuated target and then selects a wide orifice for high air flow, if necessary. Increase airflow until you meet your goals. Thus, gas flow is used to place the electro-optic transducer elements within a known vertical distance from the panel. By using this form of automation, each position tested (eg, in the first part of each panel instead of the first part of each plate of the panel when the plate includes multiple panels) At the start of the panel, more frequent adjustment of the air bearing is possible, more precise gap control for the plate is possible, and the lifetime of the modulator is optimized.

  FIG. 10A shows a remote air bearing controlled pneumatic device 1000 according to one embodiment of the present invention. The flight drawer 1005 supplies three injector flow lines A-C. Injector flow lines A-C are connected to flow control valves 1010, 1015, 1020, respectively. Flow control valves 1010, 1015, 1020 are connected to each channel airflow via cable tracks 1025 via wide or narrow orifice lines, respectively. Each flow channel line pair is connected in the VIOS 100 via each wide and narrow orifice 1030, 1035 via an air coupling to each flow line A-C of the modulator mount 20. The flight drawer provides a remotely controlled pressure range for each injector channel. The pressure in each channel is sent to the flow control valve. The flow control valve delivers compressed air to either a wide or narrow fixed orifice corresponding to a high or low air flow range. The flow from the fixed orifice is then directed to a modulator mount that holds the modulator. The air then flows to the modulator air bearing nozzles A, B, C. A check valve 1037 downstream of each orifice is used to isolate unused wide or narrow legs in each injector channel to prevent additional backflow air volume from affecting air bearing stiffness.

FIG. 10B illustrates a remote air bearing automation control 1050 according to one embodiment of the present invention. The delta tau 34AA-2 controller 1055 couples the control signals AC, AGND to one set of flight components for each VIOS 100 via corresponding optical isolation power transistors 1060-1070. Power transistors 1060-1070 drive flow control valves 1010, 1015, 1020. + V power is supplied from the flight drawer to each flow control valve. Each flow control valve is typically configured to connect the air flow from the flight drawer 1005 to the narrow orifice unless one of the three control signals AC is activated to send air flow to the wide orifice. Yes.

Claims (23)

One or more inspection heads;
One or more holders configured to house one or more electro-optic transducer elements;
Configured to hold the one or more holders to move the one or more electro-optic transducer elements from the one or more holders to the one or more inspection heads using a computer control system. A configured stage assembly; and
A clamp configured to secure the one or more electro-optic transducer elements to the one or more inspection heads;
An LCD test system comprising:   The system of claim 1, wherein the stage assembly is further configured to transport a probe contact assembly.   The one or more holders are adjustable in a plurality of directions to allow adjustment of the surface of the one or more electro-optic transducer elements relative to the one or more inspection heads. The system described in.   The one or more holders have vertical compliance to reduce residual misalignment between the one or more inspection heads and the one or more electro-optic transducer elements. System.   The one or more holders include one or more alignment reference points, and a camera disposed on the one or more inspection heads looks at the alignment reference points to align the one or more holders with the camera. The system of claim 1, wherein:   And further comprising one or more sensors configured to verify the presence and proximity of the one or more electro-optic transducer elements in the one or more holders and in the one or more inspection heads. The system according to claim 1.   The system of claim 6, wherein the one or more sensors are proximity sensors or RFID readers.   The system of claim 1, wherein the clamp is a pneumatically operated clamp. One inspection head,
At least one cleaning station configured to receive and house one electro-optic transducer element;
A stage assembly configured to hold and move the at least one cleaning station;
Have
The at least one cleaning station has one or more nozzles that supply a first gas flow to the surface of the electro-optic transducer element to unload and remove particles from the surface of the electro-optic transducer element. LCD test system featuring   The system of claim 9, wherein the first gas in the gas flow is selected from the group consisting of clean dry air or nitrogen.   The system of claim 9, wherein the first gas flow is ionized to allow removal of particles attracted by electrostatic attraction.   The at least one cleaning station includes a plurality of jets and nozzles, and the jets are configured to supply water, and the nozzles supply air or a second gas after the water is supplied. The system of claim 9, wherein the system is configured to dry the electro-optic transducer.   The system of claim 9, wherein the stage assembly is further configured to transport a probe contact assembly.   The system of claim 9, wherein the at least one cleaning station is adjustable in a plurality of directions to allow adjustment of the surface of the electro-optic transducer element relative to the inspection head.   The system of claim 14, wherein the at least one cleaning station has vertical compliance to reduce residual misalignment between the inspection head and the electro-optic transducer element.   The system of claim 9, wherein the at least one cleaning station includes one or more alignment reference points and the inspection head includes a camera.   The one or more sensors configured to verify proximity of the electro-optic transducer element to the at least one cleaning station prior to supply of the first gas. system. An electro-optic transducer element;
One or more orifices disposed on the electro-optic transducer element for gas injection;
A computer configured to control the flow and pressure of the gas;
And wherein the gas flow is used to place the electro-optic transducer element within a known vertical distance from the panel under test.   Configured to automatically adjust the vertical distance until a target signal value is detected on an image sensor disposed in an inspection head configured to hold the electro-optic transducer element of the LCD system 19. The LCD system of claim 18, further comprising a closed loop control system. A plurality of fixed orifice flow control valves connected to each of the one or more orifices to control the flow and pressure of the gas;
A solenoid valve connected to the plurality of fixed orifice flow control valves;
19. The LCD system of claim 18, wherein the solenoid valve is configured to select one of the plurality of fixed orifice flow control valves.   21. The LCD system of claim 20, wherein a first valve of the plurality of fixed orifice flow control valves has a narrower orifice than a second valve of the plurality of fixed orifice flow control valves.   21. The LCD system of claim 20, further comprising a check valve connected between each of the plurality of fixed orifice flow control valves and the one or more orifices to prevent backflow.   The solenoid valve initially selects a first one of the plurality of fixed orifice flow control valves and optionally selects a second one of the plurality of fixed orifice flow control valves. The LCD system according to claim 21.

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