JP2011066277A - Conveyance system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conveyance system that improves its efficiency. <P>SOLUTION: Based on image data imaged by a first imaging device 5, a controller 7 checks the position of a next electronic component to be sucked by a pickup collet and moves a fixed part for fixing a wafer frame W so that the electronic component may be positioned at the suction edge of the pickup collet. This eliminates the step or mechanism for adjusting its posture, and so, helps to curtail processing time. Further, since this can adjust the posture of the electronic component without nipping it in, that will prevent it from being damaged, thus preventing the decline in efficiency caused by clearing damaged electronic components. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a transport system that sucks and transports an electronic component attached to a wafer sheet fixed to a wafer frame.

  2. Description of the Related Art Conventionally, a conveyance system that picks up an electronic component from a wafer sheet on which a plurality of electronic components are attached and conveys the electronic component to a predetermined position has been proposed. This transport system includes a pickup collet that adsorbs electronic components, and a turntable that is intermittently driven with a main collet disposed at the periphery, and a plurality of processing devices are provided around the turntable. Yes. As a result, the electronic component affixed to the wafer sheet is adsorbed by the pickup collet, peeled off from the wafer sheet, delivered to the main collet at a predetermined delivery position, and conveyed along a predetermined path by the turntable. Each process such as inspection, marking, and storage is performed on the way.

  In such a transport system, each processing apparatus that performs processing such as inspection, marking, and storage sets the position to perform the processing based on a predetermined posture of the electronic component that is attracted to the main collet. Therefore, for example, when the electronic component is adsorbed in a state of being deviated from the predetermined posture when the electronic component is adsorbed from the wafer sheet or when the electronic component is transferred between the pickup collet and the main collet, Each process cannot be performed properly. For this reason, conventionally, the posture of the electronic component sucked by the suction means has been corrected.

  For example, it has been proposed to provide a device for correcting the posture of the electronic component around the turntable (see, for example, Patent Document 1). In this technique, the posture of the electronic component is corrected by sandwiching the electronic component from both sides in one direction along the main surface of the electronic component by a pair of members.

Japanese Patent Laid-Open No. 06-037134

  However, in the above-described prior art, since the device for correcting the posture of the electronic component is provided around the turntable, a process for correcting the posture is added to the processing process of the electronic component. For this reason, the time required for the entire processing process is increased, which hinders efficiency improvement.

  Further, in the above conventional technique, since the posture is corrected by sandwiching the electronic component, the electronic component is stressed when sandwiched, and the electronic component may be damaged in some cases. In this case, since the transportation system has to be stopped in order to clear damaged electronic components, it has been a cause of lowering the efficiency.

  Then, an object of this invention is to provide the conveyance system which can improve efficiency.

  In order to solve the above-described problems, a conveyance system according to the present invention includes a support unit that supports a wafer frame that holds a wafer sheet to which an electronic component is attached, and the support unit is provided along a plane of the wafer sheet. A moving part that moves in a different direction, a first adsorbing part that includes a plurality of first collets that adsorb electronic components sequentially from the wafer sheet, and affixed to the wafer sheet and then adsorbed by the first collet The image processing apparatus includes a first camera that images an electronic component, and a control unit that moves a moving unit based on imaging data captured by the first camera.

  In the transport system, the support unit may support the wafer frame in a vertical plane, and the moving unit may move the wafer frame in the vertical plane.

  In the transport system, the first camera may be disposed at a position that does not face the wafer sheet.

  Moreover, in the said conveyance system, the 2nd adsorption | suction part provided with the several 2nd collet which adsorb | sucks sequentially the electronic component adsorbed by the 1st collet, and the electronic component adsorbed by the 2nd collet are imaged The control unit may further include a second camera, and the control unit may adjust the position to which the moving unit is moved based on imaging data captured by the second camera.

  According to the present invention, the position on the wafer sheet of the electronic component to be next sucked by the first collet is confirmed based on the imaging data imaged by the first camera, and the wafer frame is based on the confirmed position. The electronic component is moved to a position facing the end where the electronic component sucks the electronic component of the first collet. Thereby, since it is not necessary to provide the process and processing apparatus for correcting an attitude | position, processing time can be shortened. Further, since the posture can be corrected without sandwiching the electronic component, the electronic component can be prevented from being damaged, and the efficiency reduction due to cleaning up the damaged electronic component can be avoided.

FIG. 1 is a diagram schematically showing a configuration of a transport system according to an embodiment of the present invention. FIG. 2 is a diagram showing the configuration of the holding device in the transport system according to the embodiment of the present invention. FIG. 3 is a diagram illustrating a configuration of a main part of the holding device of FIG. FIG. 4 is a diagram showing a configuration of a main part of the holding device of FIG. FIG. 5 is a perspective view illustrating configurations of the suction device, the turntable, and the second imaging device. FIG. 6 is a perspective view showing the configuration of the suction device and the first imaging device in the transport system according to the embodiment of the present invention. FIG. 7 is a plan view showing the configuration of the suction device and the first imaging device in the transport system according to the embodiment of the present invention. FIG. 8 is a diagram showing a configuration of a control device in the transport system according to the embodiment of the present invention. FIG. 9 is a diagram illustrating the suction conveyance operation of the conveyance system according to the embodiment of the present invention. FIG. 10 is a diagram for explaining the alignment operation of the transport system according to the embodiment of the present invention. FIG. 11 is an example of an image of an electronic component pasted on a wafer sheet. FIG. 12 is an example of an image of an electronic component affixed on a wafer sheet for explaining the position detection operation of the transport system according to the embodiment of the present invention. FIG. 13 is an example of an image of an electronic component affixed on a wafer sheet for explaining the position detection operation of the transport system according to the embodiment of the present invention. FIG. 14 is an example of an image of an electronic component affixed on a wafer sheet for explaining the focus detection operation in the position detection operation of the transport system according to the embodiment of the present invention. FIG. 15 is a diagram illustrating a calculation example of the pixel size in the X-axis direction. FIG. 16A is a diagram for explaining a method of calculating an actual size in the X-axis direction. FIG. 16B is a diagram for explaining a method of calculating an actual size in the X-axis direction. FIG. 17A is a diagram for explaining a method of calculating an actual size in the Y-axis direction. FIG. 17B is a diagram for explaining a method of calculating an actual size in the Y-axis direction. FIG. 18 is a diagram for explaining a method for calculating the distance between two points.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Configuration of transport system>
As shown in FIG. 1, the transport system 1 according to the present embodiment includes a holding device 2 that holds a wafer frame W, and an adsorption that sucks electronic components from the wafer sheet of the wafer frame W held by the holding device 2. A device 3, a turntable 4 that receives the electronic component sucked by the suction device 3 and conveys the electronic component along a predetermined path, and a first image picking up the electronic component stuck on the wafer sheet held by the wafer frame W 1, an imaging device 5, a second imaging device 6 that images an electronic component conveyed by the turntable 4, and a control device 7 that controls the operation of the entire conveyance system 1.

≪Configuration of holding device≫
The holding device 2 is composed of a pair of rod-shaped members extending in the Z-axis direction, and slides on Z rails 21a and 21b that are spaced apart from each other in the X-axis direction by different Z rails 21a and 21b. It consists of a pair of bar-shaped Z bases 22a, 22b that are separable and a pair of bar-shaped members extending in the X-axis direction, and the vicinity of both ends of one member is at the upper ends of the two Z bases 22a, 22b A pair of X rails 23a, 23b, which are fixed to each other and the vicinity of both ends of the other member are fixed to the lower ends of the Z bases 22a, 22b, respectively, and a pair slidably engaged with different X rails 23a, 23b. The X bases 24a and 24b, the upper connection portion 251 are engaged with the X base 24a, the lower connection portion 252 is engaged with the X base 24b, and a holding portion 25 for holding the wafer frame W is provided.

  Here, as shown in FIG. 3, the X base 24 a includes a Z-direction moving portion 242 a that moves the connecting portion 241 a connected to the upper end portion 251 of the holding portion 25 in the Z direction.

  As shown in FIGS. 2 and 4, the holding portion 25 is formed with an opening having a substantially rectangular shape in plan view corresponding to the planar shape of the wafer sheet at the center, and an upper connection portion connected to the X base 24 a at the upper portion. 251, a frame portion 253 having a substantially circular shape in plan view provided with a lower connection portion 252 connected to the X base 24b at the lower portion, and an opening corresponding to the planar shape of the wafer sheet at the center portion. The plate-shaped moving portion 254 having a substantially hexagonal shape in plan view, which is disposed to face the frame portion 253 so as to coincide with the opening of the H.253 and is movably supported by the frame portion 253 in the Y-axis direction. And a substantially rectangular frame shape in which an opening corresponding to the planar shape of the wafer sheet is formed at the center, and the moving part 254 so that the opening coincides with the opening of the moving part 254 in the Y-axis direction. On the negative side of the Y-axis Disposed, and a fixing portion 255 Metropolitan for fixing the wafer frame W by supporting the edge of the wafer frame W.

In the holding device 2 having such a configuration, when the Z bases 22a and 22b are moved in the Z-axis direction along the Z rails 22a and 22b, the X bases 23a and 23b fixed to the Z bases 22a and 22b and the X bases Since the holding part 25 engaged with the bases 23a and 23b also moves in the Z-axis direction, as a result, the wafer frame W fixed to the fixing part 255 is moved in the Z-axis direction.
Further, when the X bases 24a and 24b are moved in the X axis direction along the X rails 23a and 23b, the holding portion 25 engaged with the X bases 24a and 24b is also moved in the X axis direction. The wafer frame W fixed to the fixing part 255 is moved in the X-axis direction.
Further, the X base 24a is moved along the X rail 23a in the positive or negative direction in the X axis direction, the X base 24b is moved along the X rail 23b in the direction opposite to the X base 24a, and moved in the Z direction. When the part 242a is moved in the negative direction of the Z-axis direction, the holding part 25 rotates about the Y axis. As a result, the wafer frame W fixed to the fixing part 255 is rotated about the Y axis. Become.
As described above, the holding device 2 moves the wafer frame W fixed to the fixing unit 255 around the X-axis direction, the Z-axis direction, and the Y-axis.

≪Adsorption device configuration≫
The adsorption device 3 includes a base 31, a first motor 32 embedded in the base 31, and having a rotation shaft extending in a positive direction in the Z-axis direction from the upper surface of the base 31, and the first motor 32. A cam 33 attached to the rotating shaft and a moving part 34 provided on the upper surface of the base 31, slidingly contacting the cam 33 and moving in the Y-axis direction as the cam 33 moves are provided. On the moving part 34, a second motor 35 having a rotating shaft 35a extending in the negative direction in the X-axis direction is disposed. The rotation shaft 35a of the second motor 35 is connected to a substantially central portion of one surface (hereinafter referred to as “back surface”) of the disk-shaped support portion 36 along the ZY plane. A surface opposite to the back surface of the support portion 36 (hereinafter referred to as “front surface”) is radially spaced from the center portion of the support portion 36 with a suction end directed in a direction perpendicular to the X axis. A plurality of vacuum components that are selectively supplied with negative pressure or positive pressure air by a vacuum generator (not shown) to adsorb electronic components at the adsorption end or release the adsorbed electronic components. A pickup collet 37 is provided. Such a suction device 3 is disposed on the positive side in the Y-axis direction with respect to the holding device 2. Therefore, the pickup end of the pickup collet 37 that opens toward the negative side in the Y-axis direction is disposed opposite to the wafer frame W held by the holding device 2.

  Such a suction device 3 rotates the rotation shaft 35a of the second motor 35 in one direction by a predetermined angle so that the suction end of the pickup collet 37 is pitched along a circular locus concentric with the rotation shaft 35a. Just move. On the circular locus, stop positions are set on the circular locus by the number of pickup collets 37 at this pitch interval, and the suction device 3 repeats the rotation and stop of the rotating shaft 35a by the second motor 35. As a result, the movement from one stop position to the next stop position at the suction end of the pickup collet 37 and the stay at this stop position are repeated. Of the plurality of stop positions, the stop position located on the negative side in the Y-axis direction is referred to as “opposing position”, and the stop position located on the positive side in the Z-axis direction is referred to as “release position”.

  Further, when the suction device 3 drives the first motor 32 to rotate the cam 33 by a predetermined angle and moves the moving unit 34 to the negative side in the Y-axis direction, the pickup collet 37 located at the above-mentioned opposing position. The suction end of the wafer is close to the wafer frame W. At this time, if the electronic component is stuck on the wafer sheet at a position facing the suction end (hereinafter referred to as “suction position”), the electronic component is picked up by supplying negative pressure to the pickup collet 37. It will be adsorbed by the collet 37 and peeled off from the wafer sheet.

≪Turntable structure≫
The turntable 4 includes a plurality of main collets 41 that adsorb electronic components, and a transport device 42 that transports the main collets 41 along a predetermined path. The main collet 41 is selectively supplied with negative pressure or positive pressure air by a vacuum generator (not shown), so that the electronic parts are adsorbed at the ends opened vertically downward, or the adsorbed electronic parts are released. Or The transport device 42 includes a motor 421 having a rotation axis along the Z direction, and a circular table 422 to which the rotation axis of the motor 421 is attached on the back surface and is rotatably supported in the XY plane. A plurality of main collets 41 are arranged at predetermined intervals on the edge of the table 422. The transport device 42 moves the main collet 41 by one pitch along a circular locus concentric with the rotation shaft of the motor 421 and the table 422 by rotating the rotation shaft of the motor 421 by a predetermined angle. At this pitch interval, the stop position is set on the circular locus by the quantity of the main collet 41, and the turntable 4 repeats the rotation and stop of the motor 421 by the conveying device 42. The movement from the stop position to the next stop position and the stay at this stop position are repeated. At each stop position, various devices related to the transport system such as a storage device, an inspection device, and a marking device are arranged in association with the suction device 3 and the second imaging device 6.

  Here, electronic components are delivered at the stop position associated with the suction device 3. Specifically, the stop position corresponds to the release position of the suction device 3, and when the pickup collet 37 that sucks electronic components is located at the release position, When the main collet 41 moves to the stop position, the suction ends of the main collet 41 are opposed to each other with the electronic component interposed therebetween. In such a state, when the supply of the negative pressure to the pickup collet 37 is stopped and the positive pressure is supplied, and the supply of the negative pressure to the main collet 41 is started, the pickup collet 37 is adsorbed. The electronic component is attracted by the main collet 41, and the electronic component is delivered.

<< Configuration of First Imaging Device >>
The first imaging device 5 is composed of a camera 51 made of known imaging means such as a CCD (Charge Coupled Device) camera or a CMOS (Complementary Metal Oxide Semiconductor) camera, and a prism 52 for changing the optical path. Here, as shown in FIGS. 6 and 7, the prism 52 is disposed between the holding device 2 and the rotation shaft 35 a of the suction device 3 and on the back surface side of the support portion 36 of the suction device 3. The optical axis is set so as to connect the region above the wafer sheet including the electronic component located at least next to the suction position (positive side in the X-axis direction) and the vertical upper side. The camera 51 is disposed vertically above the prism 52 (on the positive side in the Z-axis direction), and images the electronic component located at the next suction position via the prism 52.

<< Configuration of Second Imaging Device >>
The second imaging device 6 is composed of known imaging means such as a CCD camera or a CMOS camera, and is disposed at a predetermined stop position (hereinafter referred to as an imaging position) of the turntable 4 and is transferred to the imaging position. The part is imaged from vertically below (the negative side in the Z-axis direction). Here, the imaging position is set after the release position. Thereby, the second imaging device 6 can pick up an image of the electronic component sucked from the wafer frame W by the suction device 3 and sucked by the main collet 41 of the turntable 4.

<Control device configuration>
As shown in FIG. 8, the control device 7 is connected to each component of the transport system and includes an interface (I / F) unit 71 that transmits and receives control signals, and the first imaging device 5 and the second imaging device 6. An image processing unit 72 that performs image processing such as contour extraction on the transmitted image data, a storage unit 73 that stores various types of information necessary for the operation of the transport system 1, and processing results and storage of the image processing unit 72 And a main control unit 74 that controls the operation of the entire transport system 1 based on the information stored in the unit 73.

  Here, the storage unit 73 stores at least an operation program 731 relating to the operation of the electronic component storage and conveyance system, template information 732 relating to a desired posture of the electronic component sucked by the main collet 41, and posture data 733. . Here, the template information 732 includes the coordinates of each vertex and the center of gravity in a desired posture of the electronic component, vector data of the contour of the desired posture, and the like.

  The main control unit 74 transmits a control signal to each component of the transport system to control the operation of each component, and the processing of the image processing unit 72 on the image data captured by the first imaging device 5 A position detection unit 742 that detects the position of the electronic component on the wafer sheet based on the result, performs a position detection operation to be described later, a processing result of the image processing unit 72 with respect to the imaging data by the second imaging device 6, and template information 732 And a correction control unit 742 for adjusting the posture of the electronic component based on the detection result of the posture detection unit 743.

  Such a control device 7 includes an arithmetic device such as a CPU, a storage device such as a memory and an HDD (Hard Disc Drive), and an input that detects input of information from the outside such as a keyboard, a mouse, a pointing device, a button, and a touch panel. I / F device that transmits and receives various information via communication lines such as the Internet, LAN (Local Area Network), WAN (Wide Area Network), etc., CRT (Cathode Ray Tube), LCD (Liquid Crystal Display) Or it is comprised from the computer provided with display apparatuses, such as FED (Field Emission Display), and the program installed in this computer. That is, the hardware device and software cooperate to control the above hardware resources by a program, and the above-described I / F unit 71, image processing unit 72, storage unit 73, and main control unit 74 are realized. . Note that the program may be provided in a state of being recorded on a recording medium such as a flexible disk, a CD-ROM, a DVD-ROM, or a memory card.

<Suction transfer operation>

  Next, with reference to FIG. 9, an electronic component suction conveyance operation by the conveyance system according to the present embodiment will be described.

  First, the drive control unit 741 of the main control unit 74 of the control device 7 uses the first imaging device 5 to electronic components that the adsorption device 3 next adsorbs among the electronic components attached to the wafer sheet held by the wafer frame W. (Hereinafter referred to as “next suction component”) is imaged (step S1).

  When an electronic component is imaged in order to detect a position on a plane, it is desirable to image from a position facing the electronic component. However, since a device for adsorbing an electronic component such as a pickup collet is usually provided at a position facing the electronic component, it is impossible to image the electronic component from that position. Therefore, in the present embodiment, as shown in FIGS. 6 and 7, a prism 52 is provided on the back surface side of the support portion 36 of the suction device 3 so that the next suction component is imaged obliquely.

  When imaging by the first imaging device 5 is performed, the drive control unit 741 causes the image processing unit 72 to perform image processing such as contour extraction of the next suction component on the imaging data. When the image processing is performed, the position detection unit 742 detects the position of the next suction component on the wafer sheet based on the image processing data (step S2). As described above, since the first imaging device 5 images the next suction component from an oblique direction, the image data and the image processing data based on the imaged data are obliquely distorted. Therefore, if these data are used as they are, the exact position of the next suction component cannot be detected. Therefore, in the present embodiment, the position detection operation is performed by the position detection unit 742 so that the accurate position of the next suction component is detected even when the next suction component is imaged from an oblique direction. Details of the position detection operation by the position detection unit 742 will be described later.

  When the position of the next suction component is detected, the drive control unit 741 moves the fixing unit 255 that fixes the wafer frame W of the holding device 2 based on the position information, and positions the next suction component at the suction position. (Step S3).

  When the next suction component is moved to the suction position, the drive control unit 741 drives the first motor 32 of the suction device 3 to rotate the cam 33 by a predetermined angle, thereby moving the moving unit 34 to the negative in the Y-axis direction. By moving to the side, the suction end of the pickup collet 37 at the opposing position is brought close to the next suction component at the suction position, and negative pressure is supplied to the pickup collet 37. As a result, the next suction component is attracted to the pickup collet 37 (step S4).

  When the next suction component is picked up by the pickup collet 37, the drive control unit 741 rotates the rotation shaft 35a of the second motor 35 of the suction device 3 by a predetermined angle (step S5). As a result, the pickup collet 37, which is located at the stop position just before the release position and sucks the electronic component, is located at the release position. In the turntable 4, a main collet 41 that does not suck electronic components is located at a stop position associated with the suction device 3, that is, a release position. Accordingly, the suction ends of the main collet 41 and the pickup collet 37 are disposed to face each other with the electronic component interposed therebetween.

  The drive control unit 741 may drive the motor 421 of the turntable 4 together with the second motor 35. As a result, the main collet 41 that has not attracted the electronic component and the pickup collet 37 that has attracted the electronic component move to the release position almost simultaneously.

  When the main collet 41 that is not attracting electronic components and the pickup collet 37 that is attracting electronic components are disposed to face each other at the release position, the drive control unit 741 supplies negative pressure to the pickup collet 37. Is stopped, positive pressure is supplied, and supply of negative pressure to the main collet 41 is started. As a result, the electronic component sucked by the pickup collet 37 is sucked by the main collet 41, and the electronic component is delivered (step S6).

  When the electronic component is delivered to the main collet 41, the drive control unit 741 returns to the process of step S1.

  As described above, according to the present embodiment, the position of the electronic component that is next picked up by the pickup collet 37 is confirmed based on the imaging data picked up by the first imaging device 5, and the pickup end of the pickup collet 37. The fixing portion 255 that fixes the wafer frame W is moved so that the electronic component is positioned at the position. Thereby, since it is not necessary to provide the process and processing apparatus for correcting an attitude | position, processing time can be shortened. In addition, since the posture can be corrected without sandwiching the electronic component, it is possible to prevent the electronic component from being damaged, and it is possible to prevent a decrease in efficiency caused by cleaning up the damaged electronic component.

<Alignment operation>
When the above-described suction conveyance operation is repeated, the suction position and posture of the electronic component on the main collet 41 may be shifted due to the influence of the wear and inertia of the suction end of the pickup collet 37 and the main collet 41. Therefore, in the present embodiment, an alignment operation for correcting the deviation is performed. The details will be described below with reference to FIG.

  When the suction conveyance operation described above is performed and the main collet 41 that has sucked the electronic component is conveyed to the imaging position, the drive control unit 741 causes the second imaging device 6 to remove the electronic component that has been sucked by the main collet 41. An image is taken (step S11).

  When imaging by the second imaging device 6 is performed, the drive control unit 741 causes the image processing unit 72 to perform image processing such as contour extraction of electronic components on the imaging data. When the image processing is performed, the posture detection unit 743 detects the posture of the electronic component conveyed to the imaging position based on the processing result of the image processing and the template information 732 in the storage unit 73 (step S12). As this posture, the current posture of the electronic component D, that is, the position of the center of gravity of the electronic component relative to the center of the main collet 41 in the X direction and the Y axis direction, the rotation angle of the electronic component around the Z axis, and these values And a deviation amount between the desired posture and the like. These values can be detected by, for example, comparing the contour or vertex or the center of gravity of the electronic component acquired by image processing with the template information 732 regarding the ideal position and angle of the electronic component. The detected value is stored as posture data 733 in the storage unit 73.

  When the posture of the electronic component is detected, the correction control unit 743 corrects the suction conveyance operation by the drive control unit 741 based on the posture data 733 (step S13). As this correction, when the fixed portion 255 is moved in step S3 in FIG. 9, the movement amount is corrected so that the main collet 41 is attracted to a predetermined posture and position.

  By performing such an alignment operation, an error or the like when the electronic component is attracted by the pickup collet 37 of the suction device 3 is adjusted so that the electronic component is attracted to the main collet 41 in a predetermined posture and position. Can be. Such an alignment operation is performed at predetermined time intervals when the power is turned on when the electronic component is conveyed with high accuracy.

<Position detection operation>
Next, the position detection operation by the position detection unit 742 performed during the above-described suction conveyance operation will be described.

  Normally, if the camera is installed such that the optical axis is perpendicular to the main surface of the wafer frame W, the pixel size of the electronic component is the same regardless of the portion on the image. Therefore, if the pixel size in the X-axis direction along the horizontal direction of the image, the pixel size in the Y-axis direction along the vertical direction of the image, and the X and Y coordinates are known, the actual size of each axis is detected from the following equation. can do.

Actual size = Pixel size x Coordinates (1)

  In the above equation (1), although the coordinates can be easily detected from the position on the image, the pixel size is the same as that on the image when the camera is not arranged perpendicular to the wafer frame W (hereinafter referred to as an oblique image). It becomes difficult to detect because it becomes larger as it goes deeper and becomes smaller as it goes closer. That is, in the oblique image of FIG. 11, the pixel size of the electronic component increases in the back of the image indicated by the symbol a, and the pixel size of the electronic component decreases in the front of the image indicated by the symbol b. Therefore, in the present embodiment, a relational expression between the pixel size and the coordinates of the electronic component is created for each of the X axis and the Y axis, and an accurate position on the oblique image is detected based on this expression. Details of this position detection operation will be described below.

For convenience, the case of the oblique image shown in FIG. 12 will be described below as an example. The oblique image shown in FIG. 12 is an image of the wafer frame W taken obliquely from above. If the lower part of the image is positive in the Y-axis direction and the left side of the image is positive in the X-axis direction, (The origin) is located on the Y-axis and on the negative side of the Y-axis from the center of the image.
The pitch size (mm) of the electronic component is (X, Y) = (7.2500, 7.2500), and the pixel size (mm) at the origin of FIG. 12 is (X, Y) = (0.0418, 0.0486).

≪Pixel size in X axis direction≫
In the oblique image of FIG. 12, the pixel size of the electronic component in the X-axis direction does not depend on the X coordinate, but depends only on the Y coordinate. Therefore, a linear function Y = aX + b is usually used as a relational expression between the pixel size in the X-axis direction and the pixel size in the Y-axis direction. However, since the focal point appears in an oblique image, the pixel size becomes infinite at the focal point. Therefore, a linear function cannot be used. Therefore, a fractional function having an infinite property at the focus is applied. The above-described linear function is replaced with a fractional function expressed by the following equation (2).

Pixel size in the X-axis direction = a / (Y coordinate + b) (2)

  Next, a and b in the above equation (2) are calculated. First, b is calculated using the property that the focal point cannot be reached. Here, the focal point is defined as a point where concentrated lines intersect on the image. That is, the alternate long and short dash lines C1 to C5 in FIG. 13 intersect at some point along with the Y axis. Therefore, the position of the focal point can be obtained by accurately obtaining one line different from the Y axis. Therefore, in the present embodiment, a line d separated from the Y axis by one device on the positive side in the X axis direction is obtained. The inclination of this line d is calculated from the coordinates of two points on the line. In the case of FIG. 13, since the coordinates of the points d1 and d2 on the line d are (173.0, 0.0) and (167.0, -145.0), the inclination is 24.1666. . As a result, the line d becomes Y = 24.1666 · X + b. Substituting the coordinates of d1 or d2 into this equation results in b = −4180.8333. Therefore, the line d is represented by Y = 24.1666 · X−4180.8333. Thereby, as shown in FIG. 14, the coordinates of the focal point f are (0.0, −4180.8333).

  The value a in the above equation (2) can be calculated by substituting the pixel size at the origin. This is shown in the following formulas (3) and (4).

0.0418 = a / (0.0 + 4180.8333) (3)
a = 1744.7588 (4)

  By substituting a and b calculated in this way into the above equation (2), the following equation (5) can be derived.

Pixel size in the X-axis direction = 174.7588 / (Y coordinate + 4180.8333)
... (5)

  When the above equation (5) is projected onto the XY coordinates, it is as shown in FIG. As can be seen from FIG. 15, by applying the above equation (5), the pixel size in the X-axis direction of the electronic component can be calculated by designating the Y coordinate.

≪Y-axis pixel size≫
The pixel size in the Y-axis direction is naturally determined once the Y coordinate is determined. Here, the pixel size in the Y-axis direction is also calculated using the fractional function shown in the following equation (6), as in the case of the X-axis direction.

Pixel size in the Y-axis direction = a / (Y coordinate + b) (6)

  Here, the coordinates of the focal point f are equivalent to the pixel size in the X-axis direction described above. Therefore, b in the above equation (6) is also equivalent to the pixel size in the X-axis direction. On the other hand, a can be calculated by substituting the pixel size at the origin into the above equation (6) as shown in the following equations (7) and (8).

0.0486 = a / (0.0 + 4180.8333) (7)
a = 203.1884 (8)

  Thereby, the pixel size in the Y-axis direction can be expressed by the following formula (9).

Pixel size in the Y-axis direction = 203.1884 / (Y coordinate + 4180.8333)
... (9)

By using the above equation (9), the pixel size in the Y-axis direction can be calculated simply by specifying the Y coordinate.
<< Calculation method for actual size >>
Next, the actual size is calculated using the three-square theorem. At this time, in an oblique image as shown in FIGS. 12 and 13, if an actual size is calculated using two points on the image, a correct value cannot be obtained. Therefore, the actual position on the wafer frame W is obtained by using the expressions relating to the pixel sizes in the X-axis direction and the Y-axis direction calculated by the method described above. Specifically, how far the coordinates of both ends of the line segment are from the origin is obtained in actual size.

  First, since the pixel size in the X-axis direction depends on the Y coordinate, it can be obtained based on the above equation (1). That is, the actual size in the X-axis direction is obtained by multiplying the distance from the origin by the pixel size in the X-axis direction. Therefore, for example, as shown in FIG. 16A, the actual size in the X-axis direction at the point P of the coordinates (x, c) is the rectangular area indicated by the symbol g in FIG. 16B, that is, 174.7588 / (c + 4180.8333). multiplied by x.

On the other hand, since the pixel size in the Y-axis direction depends on the Y-axis coordinates, the size always changes when moving in the Y-axis direction. That is, the actual size in the Y-axis direction is obtained by integrating a locus relating to the pixel size in the Y-axis direction by a predetermined interval. For example, as shown in FIG. 17A, the actual size in the Y-axis direction at the point P where the y-coordinate value is y is the area of the region indicated by the symbol h in FIG. 17B, ie, p = 203.1884 / (y + 4180.8333). Is the value obtained by integrating the curve from p ₀ to y.

≪Actual size between two points≫
Using the method described above, the actual size between two points is calculated. As an example, as shown in FIG. 18, a case where the actual size from P ₁ (−188, −125) to P ₂ (−189, 174) is measured will be described.

First, the pixel size of P ₁ is (174.588 / (− 125 + 4180.8333), 203.1884 / (− 125 + 4180.8333)) from the above equations (5) and (9), so (0. 0431, 0.0501).

Similarly, since the pixel size of P ₂ is (174.588 / (174 + 4180.8333), 203.1884 / (174 + 4180.8333)), it is (0.0401, 0.0467).

Next, the actual position (x ₁ , y ₁ ) of P ₁ is calculated.

First, as described with reference to FIGS. 16A and 16B, x ₁ is obtained by multiplying the pixel size in the x-axis direction by the x coordinate. Therefore, it is calculated by the following formula (10).

x ₁ = −181.0 · 0.0431 = −7.7990 (10)

Further, as described with reference to FIGS. 17A and 17B, y ₁ is obtained by integrating a locus relating to the pixel size in the y-axis direction by a predetermined interval. It is calculated by the following formula (11).

For even actual position of _{P 2 (x 2, y 2} ), it can be calculated in the same manner as P _1. That is, it can be calculated from the following equations (12) and (13).

x ₂ = −189.0 · 0.0401 = −7.5845 (12)

  When the position information of the electronic component is detected by the position detection unit 742 using such a method, the drive control unit 741 uses the position information to perform the above-described step S3, that is, based on the position information. The fixing portion 255 that fixes the wafer frame W of the holding device 2 is moved, and the next suction component is positioned at the suction position.

  As described above, according to the present embodiment, even when an electronic component can be imaged only from an oblique direction, an accurate position of the electronic component can be detected. Therefore, the electronic component affixed to the wafer sheet can be accurately adsorbed.

  The present invention can be applied to various apparatuses that suck and convey an object stuck on a plane such as a wafer sheet.

  DESCRIPTION OF SYMBOLS 1 ... Conveyance system, 2 ... Holding device, 3 ... Adsorption device, 4 ... Turntable, 5 ... 1st imaging device, 6 ... 2nd imaging device, 7 ... Control device, 21a, 21b ... Z rail, 22a, 22b ... Z base, 23a, 23b ... X rail, 24a, 24b ... X base, 25 ... holding portion, 31 ... base, 32 ... first motor, 33 ... cam, 34 ... moving portion, 35 ... second motor, 35a DESCRIPTION OF SYMBOLS ... Rotating shaft 36 ... Support part 37 ... Pickup collet 41 ... Main collet 42 ... Conveying device 51 ... Camera 52 ... Prism 71 ... I / F part 72 ... Image processing part 73 ... Storage part 74 ... Main control unit, 241a ... Connecting unit, 242a ... Z-direction moving unit, 251 ... Upper connecting unit, 252 ... Lower connecting unit, 253 ... Frame unit, 254 ... Moving unit, 255 ... Fixing unit, 421 ... Motor, 422 ... table, 7 1 ... operation program, 732 ... template information, 733 ... orientation data, 741 ... drive control unit, 742 ... position detection unit, 743 ... orientation detection unit, 744 ... correction control unit.

Claims (4)

A support portion for supporting a wafer frame that holds a wafer sheet to which an electronic component is attached;
A moving part for moving the support part in a direction along the plane of the wafer sheet;
A first suction part comprising a plurality of first collets for sequentially sucking the electronic components from the wafer sheet;
A first camera for imaging an electronic component affixed to the wafer sheet and next adsorbed by the first collet;
A transport system comprising: a control unit that moves the moving unit based on image data captured by the first camera. The support portion supports the wafer frame in a vertical plane,
The transport system according to claim 1, wherein the moving unit moves the wafer frame in a vertical plane. The transport system according to claim 1, wherein the first camera is disposed at a position that does not face the wafer sheet. A second suction part comprising a plurality of second collets for sequentially sucking the electronic components sucked by the first collet;
A second camera for imaging the electronic component adsorbed on the second collet;
The said control part adjusts the position which moves the said moving part based on the imaging data imaged with this 2nd camera. The conveyance system of any one of Claim 1 thru | or 3 characterized by the above-mentioned. .