Abstract:
An apparatus for inspecting and repairing a circuit defect is disclosed, which has a base; a substrate-supporting platform mounted on the base; a contact inspection module having at least one contact probe and a first driving-system that drives at least one contact probe to contact the circuits formed on the glass substrate and thereby inspect a circuit defect; a non-contact inspection module having at least one non-contact sensor and a second driving-system that drives at least one non-contact sensor to inspect the circuit defect in a non-contact manner; and a laser repair module having a laser head and a third driving-system that drives the laser head to go to the circuit defect and repair the circuit defect. A method for inspecting and repairing a circuit defect is also disclosed therewith.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an apparatus and method for inspecting and repairing circuit defects of a liquid crystal display device and, more particularly, to an apparatus that concurrently has functions of inspecting and repairing circuit defects of a liquid crystal display device.  
         [0003]     2. Description of Related Art  
         [0004]     With reference to  FIGS. 1 and 2 , a plurality of metal lines having a matrix pattern is formed on a glass substrate  10  after the array process of the manufacturing procedure of a liquid crystal display device. The metal lines include the data lines (source lines)  11  and the scan lines  12 . However, some circuit defects like the short defect  30  or the open defect  20  are very frequently formed due to imperfections of process. Generally, an open/short inspection machine is used to inspect for those kinds of defects. The inspection method of the open/short inspection machine commonly includes a non-contact type inspection and a contact type inspection. The non-contact type inspection usually uses two non-contact sensors  13 ,  14 , which may be the electrostatic capacitory coupling type. The non-contact sensor  14  serves as a signal output end, and the sensor  13  serves as a signal-receiving end. During operation, both the sensors  13 ,  14  are extremely close to the glass substrate  10 , and the distance between the sensors  13 ,  14  and the glass substrate  10  is about 100 μm only. Take the inspection of the source lines  11  for example, both the sensors  13 ,  14  are moved synchronously to find the line position of the open defect  20  first. After the line position of the open defect  20  is determined, the sensor  14  stops moving and the sensor  13  keeps moving along the line position and towards the stationary sensor  14  until the signal received by the sensor  13  has changed. Thus, the position of the open defect  20  can be found, as shown in  FIG. 1 . On the other hand, a pair of contact probes  50  can be used to touch the contact pad  40  after the line position of the short defect  30  has been found, and then the non-contact sensor  13  is used to find the position of the short defect  30 , as shown in  FIG. 2 .  
         [0005]     In the conventional procedure, the defective products picked out by the open/short inspection machine have to be repaired by a laser repair machine. The laser repair machine can mend the short defects and thus raise the yield of products. However, the inspection information obtained by the open/short inspection machine, such as the coordinates and the images of the circuit defects are firstly stored in a memory of the open/short inspection machine, and then transmitted to the laser repair machine through the Internet or a disc. As for the glass substrates that need to be repaired, they are transported independently to the laser repair machine by an additional conveyance. Certainly, additional transportation means, such as robots are used to transport the glass substrates between the open/short inspection machine and the conveyance and also between the conveyance and the laser repair machine. After the glass substrate is put in the laser repair machine, it has to be aligned again, and then be repaired according to the information transmitted from the open/short inspection machine.  
         [0006]     In such a conventional procedure, the open/short inspection machine and the laser repair machine are two distinctly separate machines, so the glass substrates have to be transported between the machines which are time-consuming. Besides, the process line is too long, and merely leads to increases in rework risk of defective products and occupied space of cleaning room. In addition to that, the glass substrate has to be aligned again in both machines, which not only increases the operation time, but also lowers the whole precision of alignment due to different coordinate systems. Thus, the use of two separate machines does not benefit the trend of an increasingly narrow line width and the automation of defect inspection and repair.  
         [0007]     With reference to  FIG. 3 , U.S. Pat. No. 5,164,565 disclosed a laser-based system for material deposition and removal. During the operation, the substrate  10  is held by an X-Y translation stage  60 , which is driven to move the substrate  10  relatively to the stationary laser head  70 . The design above-mentioned is frequently used in the inspection machine, too. However, as the substrates have become bigger and bigger, that kind of design will occupy more and more space in both machines. As a result, the cost in facility will increase, and the precision of the whole procedure will fall. The preferred design is that the laser head  70  is moved relatively to the stationary substrate. Similarly, as for the circuit defect inspection machine, it is preferred to fix the glass substrate and to move the contact probe  50  and the non-contact sensors  13 ,  14 .  
         [0008]     In these preferred design of the inspecting machines or the laser repair machine illustrated above, many similar or common alignment and transportation elements can be found in either the individual inspection machine or in the individual laser repair machine. The difference found in these two preferred machines can be only the additional inspection module or the additional laser repair module. Therefore, it is feasible to provide an apparatus having both inspection and repair functions and desirable to provide an apparatus for inspecting and repairing circuit defects to save the occupied space of the clean room or to mitigate and/or obviate the aforementioned problems.  
       SUMMARY OF THE INVENTION  
       [0009]     The object of the present invention is to provide an apparatus for inspecting and repairing a circuit defect so that the space occupied by the inspection and repair machines is reduced, and the inspection and repair of circuit defects can be carried out precisely and quickly.  
         [0010]     Another object of the present invention is to provide a method for inspecting and repairing a circuit defect so that the time for production or manufacturing can be effectively saved, and the yield can be significantly increased.  
         [0011]     To achieve the object, the apparatus for inspecting and repairing a circuit defect of the present invention includes a base; a substrate-supporting platform mounted on the base for supporting a glass substrate; a contact inspection module having at least one contact probe and a first driving-system, wherein the first driving-system drives at least one contact probe to contact the circuits formed on the glass substrate and thereby to inspect a circuit defect; a non-contact inspection module having at least one non-contact sensor and a second driving-system, wherein the second driving-system drives at least one non-contact sensor to inspect the circuit defect in a non-contact manner, and the non-contact inspection module cooperates with the contact inspection module for determining a position of the circuit defect; and a laser repair module having a laser head and a third driving-system, wherein the third driving-system drives the laser head to go to the position of the circuit defect and to repair the circuit defect.  
         [0012]     To achieve the object, the method for inspecting and repairing a circuit defect of the present invention includes the steps of providing an apparatus having a substrate-supporting platform, a contact inspection module having at least one contact probe and a first driving-system that drives at least one contact probe, a non-contact inspection module having at least one non-contact sensor and a second driving-system that drives at least one non-contact sensor, and a laser repair module having a laser head and a third driving-system that drives the laser head; putting a glass substrate that waits for inspection on the substrate-supporting platform; inspecting the circuits on the glass substrate and determining the position of a circuit defect by moving at least one contact probe and at least one non-contact sensor; moving the laser head to the circuit defect and repairing the circuit defect; and moving the inspected and repaired glass substrate out of the substrate-supporting platform.  
         [0013]     Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is a schematic view showing how the non-contact sensors inspect the open defect in the prior art;  
         [0015]      FIG. 2  is a schematic view showing how the contact probe that cooperates with the non-contact sensor inspects the short defect in the prior art;  
         [0016]      FIG. 3  is a perspective view of the laser repair apparatus of prior art;  
         [0017]      FIG. 4  is a perspective view of the apparatus for inspecting and repairing a circuit defect of the present invention;  
         [0018]      FIG. 5  is an enlarged perspective view of the contact inspection module of the present invention;  
         [0019]      FIG. 6  is an enlarged perspective view of the first vertical driving-unit of the contact inspection module of the present invention;  
         [0020]      FIG. 7  is an enlarged perspective view of the front-and-back driving-unit of the contact inspection module of the present invention;  
         [0021]      FIG. 8  is a perspective view of the non-contact inspection module of the present invention;  
         [0022]      FIG. 9  is an enlarged perspective view of the second vertical driving-unit of the non-contact inspection module of the present invention;  
         [0023]      FIG. 10  is a perspective view of the laser repair module of the present invention;  
         [0024]      FIG. 11  is a perspective view showing how the apparatus of the present invention inspects and repairs the circuit defect according to step ( 1 );  
         [0025]      FIG. 12  is a perspective view showing how the apparatus of the present invention inspects and repairs the circuit defect according to step ( 2 );  
         [0026]      FIG. 13  is a perspective view showing how the apparatus of the present invention inspects and repairs the circuit defect according to step ( 3 ); and  
         [0027]      FIG. 14  is a perspective view showing how the apparatus of the present invention inspects and repairs the circuit defect according to step ( 4 ). 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0028]     With reference to  FIG. 4 , there is shown a perspective view of the apparatus for inspecting and repairing a circuit defect of the present invention. The apparatus has a base  101 , a substrate-supporting platform  200 , a contact inspection module  300 , a non-contact inspection module  400 , and a laser repair module  500 . Moreover, the base  101  and stands  102  serve as a foundation of the whole apparatus for supporting all the components of the apparatus. The motor supporter  103  is further utilized to support and raise the motors. The substrate-supporting platform  200  substantially resembles a rectangular plate and serves to support and fix a glass substrate. The substrate-supporting platform  200  is usually made of transparent materials, such as glass or acrylate. Moreover, the transparent substrate-supporting platform  200  can improve the contrast of images by mounting a lighting module (not shown in the figure) below the transparent substrate-supporting platform  200  if higher contrast of images is needed.  
         [0029]     With reference to  FIG. 4 , there are two contact inspection modules  300  that are disposed symmetrically in the present embodiment. Next, with reference to  FIG. 6 , a contact probe  305  is mounted on an inspection head  305   a  for contacting the circuits on a glass substrate and determining the position of a circuit defect. The contact probe  305  and the inspection head  305   a  are driven by a first vertical driving-unit  301  so that they can be moved up and down. The first vertical driving-unit  301  is composed of a first bottom plate  301   a,  a linear guide way  301   b,  a servo rotary motor  301   c,  a ball screw  301   d,  a second bottom plate  301   e  that connects the linear guide way  301   b  through a linear slider (not shown in the figure), and a connecting plate  301   f  that connects the second bottom plate  301   e  and the inspection head  305   a.  Hence, through the drive of the servo rotary motor  301   c,  the contact probe  305  can be moved in a vertical direction relative to the glass substrate.  
         [0030]     In addition to the vertical movement relative to the glass substrate, it is also necessary for the contact probe  305  to be moved in a horizontal direction relative to the glass substrate. Therefore, a first horizontal driving-unit  302  is mounted, as shown in  FIG. 5 . The first horizontal driving-unit  302  is composed of a supporting crossbeam  3021 , two linear guide ways  3022 , two linear sliders  3023 , and a motor driving unit  3024 . The linear motor driving unit  3024  is further composed of a motor main body  3024   a,  a mover  3024   b,  and a corresponding driving circuit (not shown in the figure). Furthermore, the motor main body  3024   a  has a linear slider (not shown in the figure), a position sensor (not shown in the figure), and a stator (not shown in the figure). Generally, the linear motor is classified as the linear stepping motor and the linear servo motor. The linear stepping motor has a small driving force, but it can carry out the alignment by an open-loop control and has simple structure. As for the linear servo motor, it is mainly composed of a stator that is arranged in a straight line and made of a permanent magnet, a position sensor such as an optics meter, a guide set having a linear guide way and a linear slider, a driving-unit, and a mover constructed of a steel sheet encompassing a coil. The mover connects with the linear guide way and the linear slider, and can move relative to the stator. The driving-unit inputs the driving signals, such as a voltage or a current to the mover through the coil in the mover, and thereby drives the mover to move by an action force produced by the magnetic field between the mover and the stator. Accompanying the feedback signals from the position sensor, the driving voltage or current can be adjusted to form a close-loop control system.  
         [0031]     From the above-mentioned, the mover  3024   b  can be driven by the drive circuit and thereby be moved relative to the motor main body  3024   a.  Simultaneously, the mover  3024   b  connects the first bottom plate  301   a  of the first vertical driving-unit  301 , so the first vertical driving-unit  301  can be driven by the first horizontal driving-unit  302 . Consequently, the contact probe  305  can be moved in a horizontal direction relative to the glass substrate.  
         [0032]     With reference to  FIGS. 6 and 7 , the contact probe  305  can be moved forward and backward relative to the glass substrate by a linear motor driving unit  303 . The linear motor driving unit  303  is disposed symmetrically at the periphery of the substrate-supporting platform  200 , wherein the symmetrical center is approximately the central line of the glass substrate. The linear motor  303  is composed of a motor main body  3031 , a mover  3032  and its corresponding driving circuit (not shown in the figure), and a mover  3033  and its corresponding driving circuit (not shown in the figure). Like the motor main body  3024   a,  the motor main body  3031  also has a guide set (not shown in the figure), a position sensor (not shown in the figure), and a stator (not shown in the figure). The difference between the linear motor driving unit  303  and the linear motor driving-unit  3024  is that the motor main body  3031  of the linear motor driving unit  303  connects two movers, i.e. the mover  3032  and the mover  3033 , as well as their corresponding driving circuits (not shown in the figure). The mover  3032  and the mover  3033  can be driven independently by their corresponding driving circuits, which is the so-called single axis and double movers technique. Compared with the conventional linear driving-unit that uses a ball screw cooperating with a rotary motor, the linear motor driving unit  303  that applies the single axis and double movers technique can greatly reduce the space occupied.  
         [0033]     The linear motor driving unit  303  connects the first horizontal driving-unit  302  through connecting supporters  304 . The connecting supporters  304  connect the movers  3032  and  3033  of the linear motor driving unit  303  with the supporting crossbeam  3021  of the first horizontal driving-unit  302  so that the linear motor driving unit  303  can drive the first horizontal driving-unit  302  to move forward and backward. In brief, the contact probe  305  can be driven by the first vertical driving-unit  301 , the first horizontal driving-unit  302 , and the linear motor driving unit  303  respectively and thereby move in vertical, horizontal, forward and backward directions relative to the glass substrate. Therefore, the contact probe  305  can keep good contact with the circuits on the glass substrate and achieve precise inspection no matter how the circuits are designed.  
         [0034]     With reference to  FIGS. 8 and 9 , the sensor  401  in an electrostatic capacitory coupling type is driven by a shaft  4021  of an actuator  402  so that it can approach or leave the glass substrate. The actuator  402  connects the mover  4031  of the linear motor driving-unit  403 . Similarly, the linear driving-unit  403  applies the single axis and double movers technique, so it has two movers that connect respectively with their corresponding actuators. The linear motor driving-unit  403  has a stator  4033 , a linear guide way  4032 , a linear slider (not shown in the figure), and a pedestal  4034 , and can drive the sensor  401  to move horizontally.  
         [0035]     The linear motor driving-unit  403  connects with another linear motor driving-unit  404 , which also applies the single axis and double movers technique. The linear motor driving-unit  404  has a motor main body  4041 , mover  4042  (as shown in  FIG. 8 ) and mover  4043  (as shown in  FIG. 10 ), and a pair of driving circuits (not shown in the figures) corresponding respectively to the movers  4042 ,  4043 . Moreover, the motor main body  4041  is composed of a guide set (not shown in the figures), a position sensor (not shown in the figures), and a stator (not shown in the figures). The pedestal  4034  of the linear motor driving-unit  403  connects the movers  4042  of the linear motor driving-unit  404  so that the linear motor driving-unit  404  can drive the linear motor driving-unit  403  to move the sensor  401 .  
         [0036]     After the coordinate of the circuit defect is found through the non-contact sensor optionally combined with the contact probe, the laser can repair the circuit defect. For example, if the circuit defect is a short defect, the laser can repair it by cutting off the defect that causes the short.  
         [0037]     With reference to  FIG. 10 , a laser head  501  has a laser-producing element that produces a laser with power for cutting off the metal defect, which causes the short. Also, the laser head  501  further has a microptics magnification element (not shown in the figure) for providing an image of the cutting operation. Similarly, the laser head needs a driving-unit that drives it to move to the circuit defect. In the preferred embodiment, the laser head  501  connects with a mover  5021  of a linear motor driving-unit  502 . The linear motor driving-unit  502  has a stator  5022 , a linear guide way  5023 , a linear slider, and a bottom pedestal  5024 , and can drive the laser head  501  to move horizontally. In addition, if only a single laser head  501  is used, the linear motor driving unit  502  illustrated above can be replaced by conventional driving system composed by motor and ball screw.  
         [0038]     The linear motor driving-unit  502  also connects with the linear motor driving-unit  404  so that the laser head  501  can be driven to move forward and backward.  
         [0039]     Moreover, the linear motor driving-unit  404  connects with the linear motor driving-unit  502  through the mover  4043  as well as the linear motor driving-unit  403  through the mover  4042  so that the single motor main body  4041  can drive the sensor  401  and the laser head  501  independently to move relative to the glass substrate. Compared with the conventional rotary motor using a ball screw, the quantity of the transmission elements and the required space of the apparatus of the present invention are substantially reduced.  
         [0040]     Afterwards, taking the example of a short defect, the method for inspecting and repairing a circuit defect of the present invention will be described below with reference to FIGS.  11  to  14 .  
         [0041]     (1) With reference to  FIG. 11 , the glass substrate  10  that waits for inspection is firstly loaded into the apparatus of the present invention by, e.g. a robot, and then fixed on the substrate-supporting platform  200 .  
         [0042]     (2) With reference to  FIG. 12 , the contact probe  305  can be driven by the first vertical driving unit  301 , the first horizontal driving unit  302 , and the linear motor driving unit  303 , and thereby contact the circuits on the glass substrate  10  correctly. Also, the sensor  401  can be driven by the actuator  402 , the linear motor driving unit  403 , and the linear motor driving unit  404  to move close to the glass substrate  10 . Hence, the sensor  401  can inspect the circuits and determine the position! of the short defect.  
         [0043]     (3) With reference to  FIG. 13 , after the sensor  401  and the contact probe  305  have returned to their original positions, the laser head  501  is driven to the short defect by the linear motor driving-unit  502  and the linear motor driving-unit  404 . Subsequently, the laser head  501  cuts off the short defect and remedies the abnormal area into a normal area.  
         [0044]     (4) With reference to  FIG. 14 , after the circuit defect has been repaired, the laser head  501  returns to its original position, and then the glass substrate is unloaded from the apparatus of the present invention by, e.g. a robot. Finally, the apparatus returns to its original status and waits for the next substrate that needs inspection.  
         [0045]     From the above-mentioned description of the apparatus and method of the present invention, it is obvious that the present invention has the following advantages as being compared with the prior arts:  
         [0046]     (1). The apparatus of the present invention has both the functions of inspection and repair, thus the quantity of processing steps and labor hours can be greatly reduced.  
         [0047]     (2) It is unnecessary to unload and reload the glass substrate between the inspection and the repair machines, so processing accidents will be decreased and product yield can be raised.  
         [0048]     (3) The inspection and repair machines are integrated into a single entity, so the quantity of the transportation and driving-units thereof is greatly reduced. As a result, the cost of the apparatus of the present invention is substantially reduced. Moreover, the apparatus of the present invention is very suitable for the standard production line.  
         [0049]     Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.