Abstract:
A mount device for mounting an object onto a predetermined position on a base includes a support part including a first support surface for supporting one surface of the object, and a second support surface for supporting another surface of the object that neighbors the one surface of the object, and a suction nozzle for absorbing the object through the first and/or second surfaces.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates generally to mounting of an object, and more particularly to an apparatus and method for positioning or aligning, and mounting the object. The present invention is suitable, for example, for a suction collet, an apparatus having the collet, and a method using the collet, which collet positions and mounts an object, such as an optical device part, an optical element (for example, a laser diode (“LD” hereinafter), a photodiode (“PD” hereinafter), and a semiconductor device, onto a base, a container, and other base members.  
           [0002]    As hardware has recently been increasingly demanded to be smaller, electronic and optical devices to be mounted onto the hardware have been required to be smaller, and thus the mounting accuracy has become stricter. For example, in mounting the LD chip onto a base and bonding them, the LD chip should be arranged in place apart from a marking formed on the base.  
           [0003]    Conventionally, a collet has been used which absorbs a LD from a pallet for accommodating multiple LDs, and moves the LD to the base in order to mount onto the base and solder-boding the LD chip. The conventional collet forms a center suction nozzle, which has a rectangular section in the longitudinal direction and enables the collet to absorb the top of the LD through its bottom that draws a vacuum.  
           [0004]    Referring now to FIG. 10, a description will be given of the conventional mount method. FIG. 10A is a schematic sectional view showing that a collet  20  is about to absorb a LD  30  mounted on (a concave  12  in) a pallet  10 . The LD  30  has a rectangular-parallelpiped shape and is accommodated in the concave  12  in the pallet  10  in an arrow direction. The collet  20  forms, along its longitudinal direction (or direction A 1 -A 2 ), a suction nozzle  22  that draws a vacuum or decreased pressure. The collet  20  goes down in the direction A 2  from a state shown in FIG. 10A, and the bottom surface  24  of the collet  20  closely contacts a top surface  32  of the LD  30 .  
           [0005]    [0005]FIG. 10B is a schematic sectional view showing that the camera  40  is taking a picture of the LD  30  carried by the collet  20  for a rough search. The camera  40  has a field, for example, of 0.6 mm×0.5 mm, and observes an offset of the LD  30  from a reference position. Here, FIG. 10C shows a bottom view of the LD  30 . The bottom of the LD  30  has a size of 0.2 mm×0.7 mm, and forms a pair of markings  34  at two corners, respectively.  
           [0006]    [0006]FIG. 10D is a schematic sectional view showing that the LD  30  carried by the collet  20  is about to be mounted on the base  50  that has been provided on a bonding stage  70 . The base  50  shows a marking  52  used to position the LD  30  in micron level order. FIG. 10E shows a schematic sectional view of FIG. 10D viewed from a direction B. As shown in FIG. 10E, an end face  36  of the LD  30  should be arranged in place with a predetermined distance L 2  from the marking  52 . In positioning, the center of two markings  34  is set to be a reference point. The predetermined distance L 2  should be maintained with accuracy for bonding the LD  30  with accuracy. The camera  60  always monitors the markings  52 , but a drive part  25  of the collet  20  shields the field, as shown in FIG. 10D, when the LD  30  is being mounted, and hinders the LD  30  and markings  52  from being captured in the same field.  
           [0007]    Regarding the positioning accuracy of L 2 , the LD  30  is minutely movable and rotatable in the concave  12  in the pallet  10 , as shown in FIG. 10A. The camera  40  photographs the LD  30  and memorizes a position and orientation of the LD  30  relative to the pallet  10  through image processing. On the other hand, the camera  60  photographs the markings  52 , confirms and memorizes their positions through image processing. Based on data obtained by processing images taken by the cameras  40  and  60 , the LD  30  is mounted on the base  50  in the direction A 2  shown in FIG. 10D. Once the LD  30  is mounted on the base  50 , the camera  60  may capture the LD  30  and markings  52  in its field, and confirms whether L 2  is maintained through processing of an image taken by the camera  60 . If necessary, the collet  20  picks up the LD  30  from the base  50  again and corrects its position.  
           [0008]    However, the conventional mounting method has several disadvantages: The conventional mounting method has used the camera  40  and an image processor (not shown) connected to the camera  40 , and thus has a complex and costly mechanism. When it is determined that L 2  is not maintained as a result of processing images taken by the camera  60 , the collet  20  should pick up the LD  30  again to resume the image processes using the cameras  40  and  60 . This would spend much time for positioning and lower the yield. No correction would be one conceivable solution, but it would lower the reliability of the LD products. Moreover, as the image processes using the camera  40  and  60  use different systems, which add a recognition error associated with image processing of the camera  40  and a recognition error associated with image processing of the camera  60 , lowering the positioning accuracy of the LD  30 . For example, when the image processing using the camera  40  contains a recognition error of 0.1 μm and the image processing using the camera  60  contains a recognition error of 0.1 μm, the accuracy of L 2  contains an error of about 0.2 μm, which may possibly result in characteristic deterioration of the LD. The LD  30  often cannot be positioned as the error becomes larger.  
         BRIEF SUMMARY OF THE INVENTION  
         [0009]    Accordingly, it is an exemplified object of the present invention to provide a mount device and method that realizes at least one of the improved yield, the improved reduction of device&#39;s cost, and the improved positioning accuracy.  
           [0010]    In order to achieve the above object, a mount device of one aspect of the present invention for mounting an object onto a predetermined position on a base includes a support part including a first support surface for supporting one surface of the object, and a second support surface for supporting another surface of the object that neighbors the one surface of the object, and a suction nozzle for absorbing the object through the first and/or second surfaces. This mount device absorbs two surfaces of the object through the first and/or second support surfaces, approximately fixing a position and orientation of the object relative to the mount device. Therefore, this mount device does not require the camera  40  for the rough search shown in FIG. 10B and the image processor (not shown) connected to the camera  40 . Saving the rough-search time would reduce the time necessary to mount the object onto the base. The support part preferably exposes part of the object, because the partial exposure would facilitate positioning of the object.  
           [0011]    An angle formed between the first and second surfaces is set larger than that formed between two surfaces on the object. Since manufacture errors often cause a deviation in angle between two surfaces on the object, the angle formed between the first and second surfaces, which has been set larger may absorb the deviation.  
           [0012]    The suction nozzle may cover an interface between the first and second support surfaces and have such a biased center that the first and second support surfaces absorb with difference absorbing powers. Preferably, the first support surface absorbs a top surface of the object, the second support surface absorbs a side surface of the object, and the absorptive power of the first support part may be set larger than that of the second support part. As a result of the eager study by the instant inventor, the stable absorption of the object is available when the first and second support surfaces have the different absorptive powers instead of the same power, and the absorptive Dower to the top surface of the object is set to be higher.  
           [0013]    The predetermined position may be a predetermined position from a marking provided on the base, and wherein the mount device further includes an imaging part, provided at an upside of the base, which has a field to cover both of the object and marking before the object is mounted on the base, and a drive part for driving the support part so as to move the object toward the base, and correcting an alignment of the object with the marking, when the object is not arranged in place relative to the marking. According to this mount device, the imaging part aligns the object with the marking before the object is mounted onto the base, and the drive part corrects the alignment, eliminating the rough-search camera  40  shown in FIG. 10B and the image processor (not shown) connected to the camera  40 . The present invention uses the same image processing system and has higher alignment accuracy of the object with the marking or mounting accuracy of the object than the conventional mounting method that uses different image processing systems. The object may be mounted without being affected by the driving accuracy of the drive part when the object and base are aligned while arranged close to each other in the vertical direction by about 1 μm. For example, suppose that the drive part descends the support part after the alignment conducted with a large vertical distance between the object and the base. In this case, if the driving accuracy of the drive part is not so high that an attempt to vertically descending the object results in the inclined descending of the support part, the object is mounted onto the base at an offset position from a desired position. Accordingly, the present invention aligns the object with the base while arranging the object close to the base so that the mounting is less affected by the driving accuracy of the drive part. The object may be corrected before the object is mounted onto the base, and thus the correction time is shorter than the conventional mount method that cannot determine the necessity of correction until the object is mounted onto the base.  
           [0014]    The support part may expose part of the object viewed from the imaging part. The partial exposure would facilitate the alignment of the object with the marking while viewing them from the upside of them. Preferably, the imaging part may be located approximately just above the base, because the imaging part photographing a subject from the upside provides the better accuracy than photographing the subject obliquely. It is conceivable that the imaging part is provided between the base and the object and simultaneously views them in upper and lower directions through mirrors. However, this configuration is complex and expensive, and the insertion of the mirrors generates an offset between the upper and lower optical axes, thereby lowering the recognition accuracy by the imaging part. In addition, the imaging part photographs the object and the base with the different quantity of light or different contrast, and causes the recognition error in image-processing both data. Thus preferably, the imaging part is located above both of the base and the object. The drive part may include, for example, a XYZ stage for linearly moving the support part in three axial directions, and a rotary stage for rotating the support part.  
           [0015]    A mount device of another aspect of the present invention for mounting an object onto a predetermined position on a base includes a support part that includes a support surface corresponding to part of a three-dimensional shape of the object and supports the object through the support surface. Thus, the support surface is not limited to two surfaces, but may have three or more surfaces or a shape corresponding to a three-dimensional shape. The object may be a laser diode, and the base may be provided on a bonding stage. The accuracy is particularly required when the laser diode is mounted onto the base.  
           [0016]    A pallet of still another aspect of the present invention is used for a mount device that includes a first support part including a first support surface for supporting one surface of the object to be mounted onto a predetermined position on a base, and a second support part including a second support surface for supporting another surface of the object different from the one surface, and includes an accommodation part for accommodating a bottom surface of the object, wherein the first support surface supports a top surface of the object opposite to the bottom surface, and the second support surface supports a side surface of the object different from the top and bottom surfaces of the object, the depth of the accommodation part partially exposing the side surface of the object accommodated, and the second support surface covering part of the exposed side surface. This pallet uses a preset depth of the accommodation part to prevent a collision with the second surface of the mount device.  
           [0017]    A method of still another aspect of the present invention for mounting an object onto a base includes the steps of carrying the object to an upside of the base, and capturing the object and a marking formed on the base simultaneously in the same field viewed from the upside of the base, and aligning the object with the marking using an imaging part located above the object and the base. According to this mount method, the imaging part aligns the object with the marking before the object is mounted onto the base, and the drive part corrects the alignment. Therefore, this mount method does not require the rough-search camera  40  shown in FIG. 10B and image processor (not shown). The present invention uses the same image processing system and has higher alignment accuracy of the object with the marking or mounting accuracy of the object than the conventional mounting method that uses different image processing systems. The object may be corrected before mounted onto the base, and thus the correction time becomes shorter than the conventional mount method that cannot determine the necessity of the correction until the object is mounted onto the base. The imaging part photographing over the base and the object provides the better accuracy than photographing them obliquely. It is conceivable that the imaging part is provided between the base and the object and simultaneously views them in the upper and lower directions through mirrors. However, this configuration is complex and expensive, and the insertion of the mirrors would cause an offset between the optical axes, thereby lowering the recognition accuracy of the imaging part. The imaging part photographs the object and the base with the different quantity of light or different contrast would cause the recognition error in image-processing both data. Thus preferably, the imaging part is located above both of the base and the object.  
           [0018]    Preferably, the aligning step is executed when the object is arranged close to the base in a vertical direction within a predetermined distance. In particular, the object may be mounted with little influence of the driving accuracy of the drive part when the alignment is conducted with a short distance between the object and the base in the vertical direction such as about 1 μm. For example, suppose that the drive part descends the support part after the alignment conducted with a large vertical distance between the object and the base. In this case, if the driving accuracy of the drive part is not so high that an attempt to vertically descending the object results in the inclined descending of the support part, the object is mounted onto the base at an offset position from a desired position. Accordingly, the present invention aligns the object with the base after arranging the object close to the base so that the mounting is less affected by the driving accuracy by the drive part.  
           [0019]    Other objects and further features of the present invention will become readily apparent from the following description of the embodiments with reference to accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    [0020]FIG. 1 is a schematic perspective view of a mount system of one embodiment according to the present invention.  
         [0021]    [0021]FIG. 2 is a schematic sectional view of a pallet used for the mount system shown in FIG. 1  
         [0022]    [0022]FIG. 3 is a schematic perspective view of the pallet shown in FIG. 1 for accommodating laser diode chips in a matrix array.  
         [0023]    [0023]FIG. 4 is a schematic block diagram of a control system of the mount device shown in FIG. 1.  
         [0024]    [0024]FIG. 5 is a partial sectional view showing a structure of a collet used for the mount device shown in FIG. 1.  
         [0025]    [0025]FIG. 6 is a flowchart for explaining an operation of the control system shown in FIG. 4.  
         [0026]    [0026]FIG. 7 is schematic top and perspective views showing that the collet shown in FIG. 2 absorbs the laser diode chip.  
         [0027]    [0027]FIG. 8 is a schematic plane view showing a field of a camera shown in FIG. 4.  
         [0028]    [0028]FIG. 9 is a schematic sectional view of a variation of the camera shown in FIG. 4.  
         [0029]    [0029]FIG. 10 is schematic views of a conventional mount method. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0030]    Referring now to FIG. 1, a description will be given of a mount system  100  of one embodiment according to the present invention. Here, FIG. 1 is a schematic perspective view of a mount system  100 . The mount system  100  includes a pallet part  110 , a mount device  120 , and a base part  180 , uses the mount device  120  to pick up and carry the LD  30  as an object to be bonded from the pallet part  110  to the base  50 , mount the LD  30  on the base  50  with a predetermined alignment, and enables the base  50  to be bonded later.  
         [0031]    The pallet part  110  accommodates the LD  30  shown in FIG. 10, and sequentially supplies the LD  30  to the mount device  120 . The pallet part  110  includes a pallet  111 , an X-axis stage  116  and a Y-axis stage  118 . The X-axis stage  116  and Y-axis stage  118  may be considered to be part of the mount device  120  and controlled by a control part  140 , which will be described later.  
         [0032]    The pallet  111  includes multiple concave accommodation parts  112 , which are arranged in a matrix array, and each accommodates, as shown in FIG. 3, the LD  30 . Here, FIG. 3 is a schematic perspective view of the pallet  111  for accommodating LDs  30  like a matrix array. As shown in FIG. 2, the accommodation part  112  exposes part of the side surface of the LD  30  accommodated in it by a length T. The depth D of the accommodation part  112  is set so that a suction surface  134  of the collet  130 , which will be described later, covers the exposed part of the side surface, or a length T is set longer than a length C 2  of the suction surface  134 . As a result, the pallet  111  does not collide with the collet  130  due to the preset depth D of the accommodation part  112  when the collet  130  in the mount device  120  picks up the LD  30 . Here, FIG. 2 is a schematic sectional view for explaining the depth D of the accommodation part  112  of the pallet  111 . As shown in FIG. 10A, the conventional collet  20  extends from the bottom surface  24  as a suction surface vertically or in the direction A 1 , and absorbs the top surface  32  of the LD  30  accommodated in the concave  12  after descending from the top to the bottom or in the direction A 2 . Therefore, irrespective of the height or depth of the concave  12 , the pallet  10  and collet  20  have never collide with each other. On the other hand, as the collet  130  of this embodiment forms obliquely extending suction parts  132  and  134 , descends in the direction A 2 , and absorbs the LD  30 , the collet  130  may possibly collide with the surface  113  of the pallet  111  depending upon the depth D of the accommodation part  112 . Therefore, the size of the pallet  111  of this embodiment is determined so as to prevent collisions with the collet  130 .  
         [0033]    Referring to FIG. 3, the rightwardly inclining collet  30  in this embodiment in FIG. 2 picks up the LD  30  from the right row to the left row. Therefore, the collet  130  never collides, when picking up one LD  30 , with an adjacent LD  30 . Of course alternatively, the LD  30  may be picked up from the left side row to the right side row in FIG. 3. In this case, the collet  130  may possibly collide, when picking up one LD  30 , with an adjacent LD  30  depending upon the interval between adjacent accommodation parts  112 . Therefore, in this case, the pallet  111  should arrange an interval between adjacent accommodation parts  112  so that the collet  130  does not collide with the LD  30 .  
         [0034]    The pallet  111  may be made of a gel pallet that mounts the LD  30  on an adhesion tape rather than arranging the LDs  30  in the concaves  112  shown in FIG. 2. The present invention does not limit the arrangement of the LDs  30  on the pallet  111  to the matrix array, or restrict the accommodated number of LDs  30  on the pallet  111 .  
         [0035]    The X-axis stage  116  and Y-axis stage  118  move the pallet  111  in the X-axis direction and Y-axis direction so as to change a position of the LD  30  that the collet  130  picks up. The X-axis stage  116  and Y-axis stage  118  may use any structure known in the art, such as a linear motor, and a detailed description thereof will be omitted.  
         [0036]    The mount device  120  serves to pick up the LD  30  from the pallet  111 , carry it to the base  50 , align it and mounts it onto the base  50 . The mount device  120  has, as shown in FIG. 4, a drive part  121 , a feed hand or suction collet  130 , a control part  140 , a camera  142 , and an image processor  144 . Here, FIG. 4 is a schematic block diagram of a control system in the mount device  120 .  
         [0037]    The drive part  121  serves to linearly move the collet  130  in and rotate it around three axes or X-axis, Y-axis, and Z-axis directions, and includes, as shown in FIG. 1, an X-axis stage  122 , a Y-axis stage  123 , a Z-axis stage  124 , and a rotary stage  125 . As a result, the deive part  121  enables the collet  130  to pick up the LD  30  from the pallet  111 , carry the LD  30  from the pallet  111  to the base  50 , aligns the LD  30  with the base  50  above the base  50 , and mount the LD  30  onto the base  50 . The X-axis stage  122  etc. may use any structure known in the art, such as a linear motor and encoder, and thus a detailed description thereof will be omitted.  
         [0038]    The control part  140  covers one that controls each module in the mount device  120  irrespective of its name, such as a CPU and a MPU. For example, the control part  140  controls the pickup, feed, alignment and mount of the LD  30 , but FIG. 3 shows a structure of the control part  140  for controlling the alignment by the drive part  121  based on data image-processed by the image processor  144 . As mentioned above, the control part  140  in one embodiment controls the X-axis stage  116  and Y-axis stage  118 .  
         [0039]    The camera  142  has a similar structure to the camera  60  shown in FIGS. 10D and 10E, although not shown in FIG. 1, and located almost just above the base  50 . It is preferable to provide the camera  142  almost just above the base  50 . The camera  142  photographing from the upside provides better recognition accuracy than photographing obliquely.  
         [0040]    The camera  142  has a field of 0.6 mm×0.5 mm and captures both of the LD  30  and the markings  50  formed on the base  50  before the LD  30  is mounted on the base  50 . The image processor  144  is connected to the camera  142 , processes images indicative of a position and orientation of the LD  30  relative to the markings  52  taken by the camera  142 , and supplies the processed images to the control part  140 . The camera  142  and image processor  144  may use any structure known in the art, and a detailed description thereof will be omitted.  
         [0041]    Referring now to FIG. 5, a description will be given of the collet  130 . Here, FIG. 5A shows a partially transmitted sectional view of the collet  130 . FIG. 5B is a partially enlarged view of its tip. FIG. 5C is a partially transmitted top view of the collet  130 . FIG. 5D is a schematic sectional view of the collet  130 . FIG. 5E is a schematic partial perspective view of the tip of the collet  130 .  
         [0042]    The collet  130  is made of conductive ultra steel having good workability. The collet  130  has suction surfaces  132  and  134 , and forms a suction nozzle  136  at an interface between the suction surfaces  132  and  134  so that the nozzle  136  covers both of the suction surfaces  132  and  134 .  
         [0043]    The suction surface  132  absorbs the top surface  32  of the LD  30  shown in FIG. 10A, and the suction surface  134  absorbs the side surface  33  of the LD  30  shown in FIG. 10B. The collet  130  absorbs two surfaces of the upper surface  32  and side surface  33  of the LD  30  through the suction surfaces  132  and  134 . Thus, the rough-search camera  40  shown in FIG. 10B and an image processor (not shown) connected to the camera  40  are not needed, and the mechanism becomes simple and inexpensive. The rough-search time is saved, lowering the necessary time to mount the LD  30  onto the base  50 , and improving the yield.  
         [0044]    Since it is sufficient that the collet  130  of this embodiment secures the object, the collet  130  may have a shape corresponding to the shape of the object and such a shape may have three or more surfaces and three-dimensional shape that cannot be strictly divided into two surfaces, such as curved and elliptical surfaces.  
         [0045]    The suction nozzle  136  is connected to the suction surfaces  132  and  134 , and serves to draw a vacuum. The suction nozzle  136  shifts towards the suction surface  132  to maintain a stable orientation of the LD  30  when absorbing it. Therefore, the absorptive power by the suction surface  132  is stronger than that by the suction surface  134 . As a result of the eager study by the instant inventor, the stable absorption of the LD  30  is available when the suction surfaces  132  and  134  have different absorptive powers instead of having the same power, and the absorptive power to the top surface  32  of the LD  30  is set to be higher.  
         [0046]    The LD has almost rectangular-parallelopiped shape and forms 90° between the top and side surfaces  32  and  34  of the LD  30 . On the other hand, an angle between the suction surfaces  132  and  134  is set to be slightly larger, because the collet  130  may absorb the LD  30  even when a manufacture error makes the larger angle between the top and side surfaces  32  and  34 . As a result, the suction surfaces  132  and  134  may absorb a manufacture error deviation between two surfaces on the LD  30 . The angle between the suction surfaces  132  and  134  is set, for example, to be larger than the manufacture error of the LD  30 . Since the excessively large angle would result in a loss of two-surface binding of the LD  30 , the angle between the suction surfaces  132  and  134  is set to be within a range to maintain two-surface binding.  
         [0047]    An interface  135  between the suction surfaces  132  and  134  is set apart from the attachment reference part  139  by a certain distance, as shown in FIG. 5D.  
         [0048]    The collet  130  obliquely extends, as shown in FIG. 2, from the suction surfaces  132  and  134 . The suction surfaces  132  and  134  expose part of the LD  30  after they absorb the LD  30 . Therefore, a length C 1  of the suction surface  132  shown in FIG. 2 is smaller than a width of the top surface  32  of the LD  30 . As discussed, the length C 2  of the suction surface  134  shown in FIG. 2 is set smaller than T of the LD  30 . The partial exposure of the LD  30  by the collet  130  would facilitate the alignment between the LD  30  and markings  52  with a view from the upside.  
         [0049]    The base part  180  includes the base  50  and bonding stage  70 . The base part  180  may apply any structure known in the art, and a detailed description will be omitted.  
         [0050]    Referring now to FIG. 6, a description will be given of an operation of the control part  140 . Here, FIG. 6 is a flowchart showing the operation of the control part  140 . The flowchart shown in FIG. 6 may be implemented as a computer executable program.  
         [0051]    First, the control part  140  controls the drive part  120  so as to pick up the LD  30  from the pallet  111  (step  1002 ). The control part  140  may also control the X-axis stage  116  and the Y-axis stage  118 . The control part  140  further controls drawing a vacuum of the suction nozzle  136  in the collet  130 , whereby the LD  30  may be picked up from the accommodation part  112  at a desired position in the pallet  111 . As shown in FIG. 2, the drive part  121  descends in the direction A 2  after setting the suction surface  134  close to the side surface  33  on the LD  30 .  
         [0052]    [0052]FIG. 7 shows this state. Here, FIG. 7A is a plane view of the collet  130  absorbing the LD  30 . FIG. 7B is its perspective view. The LD  30  and the collet  130  have different sizes in both figures for constructional conveniences.  
         [0053]    As shown in FIGS. 7A and 7B, the suction surface  132  exposes part of the LD  30  after it absorbs the LD  30 . In picking up the LD  30 , as discussed with reference to FIG. 2, the collet  130  does not collide with the top surface  113  of the pallet  111 . In picking up the LD  30  from the pallet  111  using the collet  130 , the LD  30  is absorbed with a clearance between the LD  30  and the collet  130 . The LD  30  is absorbed by the suction surfaces  132  and  134  shown in FIG. 2, and a position and orientation of the LD  30  are fixed relative to the collet  130 . In other words, the absorptive power of the collet  130  absorbs the LD  30  on the suction surfaces  132  and  134 , and the orientation of the LD  30  becomes stable in the direction X and θ Z  by the absorptive power and binding surfaces of the collet  130 . The impact applied to the LD  30  is affected by the own weight of the LD  30  and absorptive power, but it does not damage a fine part, such as an optical device, since the fine part has small weight and thus the impact is small.  
         [0054]    Next, the control part  140  controls the drive part  121  so as to feed the LD  30  to the upside of the base  50  (step  1004 ). The control part  140  may controls so as to descend the LD  30  so that the LD  30  is set apart from the base  50  by a predetermined distance in the vertical direction. The alignment is provided at this point. In the alignment between both members are provided while a distance between the LD  30  and the base  50  is set about 1 μm in the vertical direction, the LD  30  may be mounted without affected by the accuracy of the drive part  121  that descends the collet  130  and LD  30 . For example, suppose that the drive part  121  descends the collet  130  after the alignment with a large vertical distance between the LD  30  and the base  50 . In this case, if the driving accuracy by the drive part  121  is not so high that an attempt to vertically descend the collet  130  results in the inclined descending of the collet  130 , the LD  30  is mounted onto the base  50  at an offset position from a desired position. On the other hand, the instant embodiment aligns the LD  30  with the base  50  after arranging the LD  30  close to the base  50  so that mounting of the LD  30  is less affected by the driving accuracy by the drive part  121 .  
         [0055]    The driving part  141  then receives image data taken by the camera  142  from the image processor  144  (step  1006 ), and determines whether the alignment is proper or the length L 2  shown in FIG. 4 is the predetermined distance (step  1008 ). As discussed, the length L 2  is a distance between the marking  52  and the LD  30 . The camera  142  has a field shown in FIG. 8. Here, FIG. 8 shows a plane view of the field of the camera  142 .  
         [0056]    When the alignment is insufficient, the control part  140  controls the drive part  121  so as to align the LD  30  and returns to the step  1006  (step  1010 ). The alignment sets to L 2  a distance between a center  35  between the markings  34  shown in FIG. 8 and the marking  52 , and let a line that passes the center  35  and is perpendicular to a line connecting a pair of markings  34  pass the marking  52  or become parallel to a line that passes a center between the markings  52  and is perpendicular to a line connecting a pair of markings  52 . Thereby, the LD  30  is aligned with the marking  52  with a desired distance and orientation or angle.  
         [0057]    According to the mount device  120 , the control part  140  thus aligns the LD  30  with the marking  52  before the LD  30  is mounted onto the base  50 , and corrects the alignment through the drive part  121 . Therefore, the mount device  120  does not require the rough-search camera  40  shown in FIG. 10B and the image processor (not shown). The instant embodiment uses the same image processing system and has higher alignment accuracy of the LD  30  with the marking  52  or mounting accuracy of the LD  30  than the conventional mounting method that uses different image processing systems. For example, the image processing by the camera  142  contains a recognition error as in the cameras  40  and  60 , the recognition accuracy of the mount device  100  of this embodiment is twice as high as the conventional mount method shown in FIG. 10. Moreover, the alignment may be corrected before the LD  30  is mounted onto the base  50 , the correction time becomes shorter than the conventional mount method that determines the necessity of the correction only after the LD  30  is mounted onto the base  50 .  
         [0058]    The camera  142  is located above both of the LD  30  and base  50 , and provides better alignment accuracy than a camera located between the LD  30  and base  50 . For example, as shown in FIG. 9, it is conceivable to use a camera  80 , instead of the camera  142 , which includes an imaging part  81  and an optical system  82 . The optical system  82  includes mirror  84  and  85 , and photographs the LD  30  and  50  simultaneously. However, this configuration is complex and expensive, and the insertion of the mirrors  84  and  85  causes an offset between optical axes of upper and lower rays R 1  and R 2 , thereby lowering the recognition accuracy of the imaging part  81 . In addition, when the imaging part  81  photographs the LD  30  and the base  50 , the quantity of upper and lower light is not the same and thus the contrast is not the same, causing the recognition error in image-processing both data. Moreover, it is necessary to separate the LD  30  and the base  50  by a distance necessary for insertion of the camera  80 . In this case, after the alignment using the camera  80 , the camera  80  should be removed and the LD  30  should be mounted onto the base  50 . However, if the driving accuracy of the drive part  121  is not so high that an attempt to vertically descend the LD  30  results in the inclined descending of the collet  130 , the LD  30  is mounted onto the base  50  at an offset position from a desired position. Therefore, the camera  142  has higher recognition accuracy than the camera  80 .  
         [0059]    The control part  140  controls, when determining that the alignment is completed (step  1008 ), the drive part  121  so as to mount the LD  30  onto the base  50  (step  1012 ). Then, the LD  30  is solder-bonded with the base  50 . Since L 2  is secured with predetermined accuracy, the bonding accuracy improves and provides an LD having good optical characteristics. Then, in mounting another LD  30  onto the same base  50  or mounting another LD  30  onto another base  50 , the control part  140  repeats the procedure from the step  1002 .  
         [0060]    Further, the present invention is not limited to these preferred embodiments, and various modifications and variations may be made without departing from the spirit and scope of the present invention.  
         [0061]    Thus, the inventive mount device and method do not require the rough-search camera  40  shown in FIG. 10B or the image processor (not shown) connected to the camera  40 , simplifying its mechanism and reducing the cost. In addition, the inventive mount device and method do not require the time for the rough search, reducing the time necessary to mount the object onto the base, improving the yield. Moreover, the inventive mount device and method use the same image processing system, and thus provides higher alignment accuracy or mounting accuracy of the object to the marking.