Abstract:
A bonding method uses a bonding apparatus, which includes a frame, a first feeding mechanism, a second feeding mechanism, and a bonding mechanism. The first feeding mechanism is mounted on the frame and includes a turntable capable of rotating relative to the frame. A plurality of workpiece seats are arranged on the turntable. Each workpiece seat defines a plurality of air holes. The second feeding mechanism is mounted on the frame and includes a first carrier and a second carrier. The first carrier includes a plurality of holding seats and the second carrier including a plurality of temporary holding seats. The first carrier is capable of rotating to stack on the second carrier. The bonding mechanism is movably mounted on the frame to correspond to the workpiece seats or the second carrier.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a divisional application of U.S. patent application Ser. No. 12/494,574, filed on Jun. 30, 2009. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present invention relates generally to bonding apparatuses and methods and, more particularly, to a bonding apparatus and a bonding method for bonding at least two workpieces together. 
     2. Description of Related Art 
     In manufacturing electronic devices, some components, such as glass sheets and printed circuit boards, need be bonded together. For example, a touch panel includes a glass substrate, a conductive layer, and a protecting layer. The glass substrate, the conductive layer, and the protecting layer should be bonded together. Nowadays, more and more electronic devices, e.g., mobile phones, personal digital assistants, and liquid crystal display devices, utilize touch panels. 
     Before bonding components together, the components should be positioned, so that the edges of the components can be leveled in a same line. A typical bonding apparatus includes a belt with glue to feed to the components. If a component is put in an undesired position, the component must be repositioned on the sticky belt. However, some components deform and wrinkle easily. Thus, in the process of repositioning the components, the components may deform or wrinkle, resulting in unqualified products. 
     Therefore, a bonding apparatus and a bonding method which overcome the above-described shortcomings are desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout several views, and all the views are schematic. 
         FIG. 1  is a perspective view of one embodiment of a bonding apparatus, the bonding apparatus including a frame, a first feeding mechanism, a second feeding mechanism, a bonding mechanism, and a camera module. 
         FIG. 2  is a perspective view of the first feeding mechanism of  FIG. 1 . 
         FIG. 3  is a perspective view of the second feeding mechanism of  FIG. 1 . 
         FIG. 4  is a perspective view of a second workpiece located on the second feeding mechanism of  FIG. 1 . 
         FIG. 5  is a perspective view of the bonding mechanism and part of the frame of  FIG. 1 . 
         FIG. 6  is a perspective view of part of the bonding mechanism of  FIG. 1 . 
         FIG. 7  is a flow chart of an embodiment of a bonding method. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , an embodiment of a bonding apparatus  100  includes a frame  10 , a first feeding mechanism  20 , a second feeding mechanism  30 , a bonding mechanism  40 , and a camera module  50 . A first workpiece  200  is fed by the first feeding mechanism  20 , and a second workpiece  300  is fed by the second feeding mechanism  30 . In the illustrated embodiment, the first workpiece  200  is made of glass, and the second workpiece  300  is made of foam sponge. 
     The frame  10  includes a platform  11  defining an opening  111  (see  FIG. 5 ). A first switch  113 , a second switch  115 , and a third switch  117  are mounted on the platform  11 . 
     Referring to  FIG. 1  and  FIG. 2 , the first feeding mechanism  20  includes a turntable  21 , a plurality of workspace seats  23  mounted on the turntable  21 , and a drive mechanism  25  to drive the turntable  21  to rotate. The turntable  21  defines two cutouts  211  at opposite sides of a periphery. The cutouts  211  are configured for preventing the turntable  21  from obstructing the camera module  50 . Each workpiece seat  23  defines a plurality of air holes  231 . The drive mechanism  25  includes an electric motor  251  and a divider  253  to drive the turntable  21 . Alternatively, the turntable  21  may be driven by a pneumatic cylinder. In the illustrated embodiment, two opposite workpiece seats  23  are arranged at the turntable  21 . The first workpiece  200  may be held on the workpiece seats  23  by a vacuum suction method. 
     Referring to  FIGS. 1 and 3 , the second feeding mechanism  30  includes a bracket  31  mounted on the platform  11 , a first carrier  32 , a second carrier  33 , a pneumatic cylinder  34 , and an ionic-wind bar  35 . The bracket  31  includes a base body (not labeled) and two arms (not labeled) extending from opposite ends of the base body. The ionic-wind bar  35  is positioned between top ends of the arms. The first carrier  32  is pivotally connected to the base body of the bracket  31  and the second carrier  33  is fixed on the base body. The first carrier  32  can be rotated to fold onto the second carrier  33 . The pneumatic cylinder  34  is positioned at a side of the bracket  31  to drive the first carrier  32  to rotate. The first carrier  32  includes a plurality of holding seats  321 , each defining a plurality of air holes  3211 . The second carrier  33  includes a plurality of temporary holding seats  331 , each defining a plurality of air holes  3311 . 
     Referring to  FIG. 4 , the second workpiece  300  is substantially rectangular and defines a rectangular slot  301 . A strip of first protecting film  303  is attached with a plurality of second workpieces  300 . Alternatively, the first protecting film  303  may be attached with six, or less than or more than six second workpieces  300  as in the illustrated embodiment. A top surface of each second workpiece  300  is coated with a second protecting film  305 . The bottom surface of each second workpiece  300  attached to the first protecting film  303  is applied with adhesive, and the first protecting film  303  has a releasing coating coated thereon to facilitate separating the first protecting film  303  from the second workpieces  300 . The first carrier  32  forms at least one positioning block  3213 . In the illustrated embodiment, the first carrier  32  includes six holding locations  321  aligned in a line, and the second carrier  33  includes six temporary holding locations  331  aligned in a line corresponding to the holding locations  321 . The temporary holding seats  331  are protrusions that can extend in the slots  301  of the second workpieces  300 . The temporary holding seat  331  has a thickness larger than the second workpiece  300  so that the adhesive does not contact the second carrier  33 . The ionic-wind bar  35  can remove static electricity of the first carrier  32  and the second carrier  33 . Alternatively, the ionic-wind bar  35  may be other static electricity removing structures such as an ionic-wind gun and a static electricity bar. 
     Referring to  FIG. 1  and  FIG. 5 , the bonding mechanism  40  is mounted on the platform  11  of the frame  10 . The bonding mechanism  40  includes two sidewalls  41  extending along a first direction, a cross beam  42  slidably mounted on the sidewalls  41  and extending along a second direction perpendicular to the first direction, a slidable holder  43  slidably mounted on the cross beam  42 , and a slidable platform  44  slidably mounted on the slidable holder  43 . The sidewalls  41  include a first guide rail along the first direction, i.e., the X-axis, the cross beam  42  includes a second guide rail along the second direction, i.e., the Y-axis, and the slidable holder  43  includes a third guide rail along a third direction, i.e., the Z-axis. The slidable platform  44  includes a pickup head  431  and a pneumatic cylinder  433  connected to the pickup head  431 . The pneumatic cylinder  433  can control the pickup head  431  to slide along the Z-axis. 
     Referring to  FIG. 1  and  FIG. 6 , the camera module  50  includes a first module  51  and a second module  52 . In the illustrated embodiment, the camera module  50  is a charge coupled device (CCD) module. The first module  51  and the second module  52  are fixed on the frame  10 . The first module  51  is mounted on a top portion of the frame  10  and corresponds to the first feeding mechanism  20  and the second feeding mechanism  30 . The second module  52  is mounted on the bottom side of the platform  11  of the frame  10  and corresponds to the opening  111 . In the illustrated embodiment, the first module  51  includes four lenses  511  with image sensors and the second module  52  includes four lenses  521  with image sensors. A standard coordinate value between the first module  51  and the second module  52  is predetermined and stored in a controller of the bonding apparatus  100 . 
     Referring to  FIG. 4  and  FIG. 7 , a method of bonding the first workpiece  200  and the second workpiece  300  together via the bonding apparatus  100  is described as follows. 
     The first workpiece(s)  200  is mounted on the first feeding mechanism  20  and a position of one of the workpiece(s)  200  is measured. That is, one first workpiece  200  is mounted on one of the workpiece seats  23  of the first feeding mechanism  20 . The first workpiece  200  is an eligible workpiece which has been measured beforehand. The first switch  113  is turned on and the first workpiece  200  is held on the workpiece seat  23  by a suction force from the air holes  231 . The second switch  115  is turned on to rotate the turntable  21 , so that the workpiece seat  23  holding the one first workpiece  200  is carried to a position corresponding to the bonding mechanism  40 . The first module  51  captures a first image of the first workpiece  200  to determine a positioning value of the first workpiece  200 . Another first workpiece  200  may be put on another workpiece seat  23  of the first feeding mechanism  20 . 
     The second workpiece(s)  300  is placed on the second feeding mechanism  30 . That is, a group of second workpieces  300  are mounted on the first carrier  32  of the second feeding mechanism  30  with the second protecting film  305  facing the first carrier  32 . The second workpieces  300  can be positioned on the first carrier  32  using the positioning block  3213  as reference. The first protecting film  303  is removed from the second workpieces  300 . 
     The second workpiece(s)  300  is moved from the first carrier  32  to the second carrier  33  of the second feeding mechanism  30 . That is, the third switch  117  is turned on and the second workpieces  300  are held on the first carrier  32  by a suction force from the air holes  3211 . The pneumatic cylinder  34  is turned on to drive the first carrier  32  to rotate to an angle of 180 degrees. The first carrier  32  is thus folded over/on the second carrier  33 , and the temporary holding seats  331  extend into the cutouts  301  of the second workpieces  300  correspondingly. The third switch  117  is turned off so that the second workpieces  300  are freed from the first carrier  32  and mounted on the second carrier  33 . The pneumatic cylinder  34  is turned on to drive the first carrier  32  to rotate through an angle of 180 degrees, thus returning to the original position. 
     The bonding mechanism  40  picks up one second workpiece  300 . The pickup head  431  moves to a position above the second carrier  33  of the second feeding mechanism  30 . The pickup head  431  picks up the second workpiece  300  from the second carrier  33 . 
     The camera module  50  captures a second image of the second workpiece  300  to assist selecting an eligible second workpiece  300  and positioning the second workpiece  300  in a desired position. The second module  52  of the camera module  50  takes pictures of the second workpiece  300  and transmit the pictures to the controller. The controller compares the size and shape of the second workpiece  300  with the desired size and shape stored in the controller beforehand. If the measured size and shape are inconsistent to the desired size and shape, the pickup head  431  returns the second workpiece  300  on the second carrier  33 , and picks up another second workpiece  300 . If the picked second workpiece  300  has size and shape consistent to the desired size and shape, i.e., the second workpiece  300  is eligible, the controller compares a measured coordinate value between the second workpiece  300  and the first workpiece  200  corresponding to the second workpiece  300  with the standard coordinate value between the second workpiece  300  and the first workpiece  200 . If the measured coordinate value is inconsistent to the standard coordinate value, the controller controls the pickup head  431  to slide along the X-axis or the Y-axis, or rotate around the Z-axis, until the second workpiece  300  is in a desired position. While moving, the lenses  521  is taking pictures all along and the controller compares the measured coordinate with the standard coordinate value all along. 
     The first workpiece  200  and the second workpiece  300  are bonded together by the bonding mechanism  40 . The pickup head  431  moves along the Z-axis towards the first workpiece  200 . The second workpiece  300  is bonded to the first workpiece  200 . The pickup head  431  releases the second workpiece  300  and moves away from the second workpiece  300 . 
     The bonded first workpiece  200  and second workpiece  300  is unloaded from the bonding apparatus  100 . The turntable  21  is rotated to eject the bonded first workpiece  200  and second workpiece  300  from the bonding mechanism  40 . By rotating the turntable  21 , another first workpiece  200  is in the position corresponding to the boning mechanism  40 . If more first workpiece  200  and second workpiece  300  need to be bonded, another first workpiece  200  is put on one of the workpiece seats  23 . 
     If more first workpiece  200  and second workpiece  300  need to be bonded together, the above-described steps are repeated from the step of the bonding mechanism  40  picking up another workpiece  300 . Furthermore, if no eligible second workpiece  300  is on the second carrier  33 , the ineligible second workpiece  300  is removed from the second carrier  33  and the step of mounting the second workpiece(s)  300  on the second feeding mechanism  30  and removing the second workpiece(s)  300  from the first carrier  32  to the second carrier  33  is repeatedly performed before picking one second workpiece  300 . 
     Alternatively, certain of the steps described above may be removed, others may be added, and the sequence of steps may be altered. For example, the position of the first workpiece  200  may be measured at any time before bonding to the second workpiece  300 . Similarly, the position of the second workpiece  300  may be measured at any time before bonding to the first workpiece  200 . The sequence of mounting the first workpiece  200  on the first feeding mechanism  20  and mounting the second workpiece  300  on the second feeding mechanism  30  may be altered or the steps may be performed simultaneously. The sequence of moving the second workpiece  300  from the first carrier  32  to the second carrier  33  mounting the first workpiece  200  on the first feeding mechanism  20  may also be altered. 
     An adjustable range by moving the pickup head  431  is relatively small. Therefore, if the positions of the first workpiece  200  on the workpiece seat  23  and the second workpiece  300  on the first carrier  32  are too far away from desired positions, the first workpiece  200  and the second workpiece  300  should be rearranged. The first workpiece  200  and the second workpiece  300  will not deform or wrinkle during rearrangement, because they are held in position by suction force. In addition, the first protecting film  303  is to be manually removed rather than automatically because a machine providing a constant force is likely to deform or wrinkle the second workpiece  300 . A plurality of second workpieces  300  mounted on one first protecting film  303  results in a high efficiency during removal of the first protecting film  303 . 
     Finally, while various embodiments have been described and illustrated, the disclosure is not to be construed as being limited thereto. Various modifications can be made to the embodiments by those skilled in the art without departing from the true spirit and scope of the disclosure as defined by the appended claims.