Chip pickup device, chip mounting device, and chip pickup method

Abstract

According to the present invention, the position of a camera visual field V71 of a recognition camera 71 for imaging a chip C is adjusted in an X direction in accordance with: a blind spot R52 (existence range) of a suction plate 52 of a pickup head 51 when suctioning the chip C held by an adhesive sheet H; and the width Xc (size) of the chip C in the X direction (fig. 3B, steps S107, S108). Accordingly, the chip C near a chip supply position Ls is kept in the camera visual field V71 while avoiding the blind spot R52 of the suction plate 52, and the positional relationship between the chip C and the camera visual field V71 can be made appropriate in accordance with the width Xc of the chip C. As a result, a chip recognition image Ir of the chip C can be acquired while suppressing the influence of: the elongation of the adhesive sheet H that holds the chip C; and the distortion due to the deviation of the chip C with respect to the camera visual field V71.

Description

Chip pickup device, chip mounting device, and chip pickup method

[0001] The present invention relates to a technique for picking up a chip held on a sheet, and more particularly to a technique for capturing an image of the chip and recognizing the chip.

[0002] Patent Document 1 describes a component mounting device that mounts wafer components (chips) included in a diced wafer onto a substrate. Generally, multiple chips included in a wafer are provided attached to an adhesive sheet. Therefore, a device for picking up chips is provided with a push-up member, and chips pushed up by the push-up member through the sheet are picked up by a head. Furthermore, such a device performs an operation of transporting the wafer in the transport direction, sequentially supplying multiple chips included in the wafer to a chip supply position, and then picking up the chips from the chip supply position. In this case, to accurately pick up the chips from the chip supply position, an image of the chips is taken before they are supplied to the chip supply position, and the position of the chips is recognized in advance.

[0003] Patent No. 4800076

[0004] However, the sheet may be stretched by the chip being pushed up through the sheet, resulting in a misalignment of the relative positional relationship between the sheet and the chip between the time the chip is imaged and the time the chip is picked up. In such cases, it becomes difficult to accurately pick up the chip from the chip supply position based on the recognized chip position. Therefore, it is preferable to image the chip near the chip supply position. However, chips adjacent to the chip supply position are hidden by the head that picks up the chip from the chip supply position. Therefore, it is necessary to image the chip near the chip supply position while preventing interference with the head.

[0005] Furthermore, if the chip is positioned off-center relative to the camera's field of view, the image of the chip will be distorted due to the aberration of the camera lens. Meanwhile, the sizes of the chips to be picked up vary. Therefore, depending on the size of the chip, the chip may be so off-center relative to the camera's field of view that it may not be possible to properly capture the chip.

[0006] This invention has been made in consideration of the above-mentioned problems, and aims to make it possible to acquire images of chips while suppressing the effects of distortion caused by stretching of the sheet holding the chips and by the chip being biased relative to the camera's field of view.

[0007] The chip pickup device of the present invention includes a wafer transport mechanism that supplies chips to a chip supply position by transporting a wafer containing a plurality of chips held on a sheet in a predetermined transport direction; a push-up unit that pushes up the chips supplied to the chip supply position through the sheet; a head that has a pickup section that adsorbs the chips, and adsorbs the chips pushed up by the push-up unit and held on the sheet to the pickup section, and then removes the chips by moving the pickup section away from the sheet; a wafer camera that has a camera field of view and captures images of chips on the wafer that are included in the camera field of view; a camera drive mechanism that drives the wafer camera in the transport direction; and an imaging control unit that adjusts the position of the camera field of view of the wafer camera that captures the chips in the transport direction by controlling the camera drive mechanism in accordance with the range of the pickup section when adsorbing the chips held on the sheet and the size of the chips in the transport direction.

[0008] A chip mounting device according to the present invention includes the above-described chip pickup device and a mounting section that mounts the chip picked up by the chip pickup device on a mounting target.

[0009] The chip pickup method of the present invention includes the steps of: supplying the chips to a chip supply position by transporting a wafer including a plurality of chips held on a sheet in a predetermined transport direction; pushing up the chips supplied to the chip supply position through the sheet with a push-up unit; adsorbing the chips pushed up by the push-up unit and held on the sheet to a pickup section of the head; and then removing the chips by moving the pickup section away from the sheet; adjusting the position of the camera field of view of a wafer camera that images the chips in the transport direction depending on the range of the pickup section when adsorbing the chips held on the sheet and the size of the chips in the transport direction; and imaging the chips on the wafer that are included in the camera field of view with the wafer camera.

[0010] In the present invention (chip pickup device, chip mounting device, and chip pickup method) configured as described above, a wafer containing multiple chips held on a sheet is transported in a predetermined transport direction, thereby supplying the chips to a chip supply position. The chips supplied to the chip supply position are then pushed up by a push-up unit through the sheet. The chips pushed up by the push-up unit and held on the sheet are then adsorbed onto a pickup unit of the head, and the pickup unit is then separated from the sheet, thereby removing the chips. Furthermore, chips on the wafer included in the camera field of view are imaged by a wafer camera. In particular, the position of the camera field of view of the wafer camera that images the chips is adjusted in the transport direction depending on the range of the pickup unit of the head when adsorbing the chips held on the sheet and the size of the chips in the transport direction. This allows chips near the chip supply position to be included in the camera field of view while avoiding the range of the pickup unit, and the positional relationship between the chips and the camera field of view can be optimized depending on the chip size. As a result, images of the chips can be acquired while suppressing the effects of distortion due to stretching of the sheet holding the chips and deviation of the chips relative to the camera field of view.

[0011] The chip pickup device may further include a chip recognition unit that performs chip recognition by capturing an image of the chip captured by the wafer camera, and the image capture control unit sets a recognition target range in which the chip to be recognized is located based on the range of the pickup unit's presence when adsorbing the chip held on the sheet and the size of the chip in the transport direction. The camera drive mechanism adjusts the position of the wafer camera in the transport direction so that the camera field of view includes the recognition target range, and the wafer camera captures the recognition target range to acquire the chip recognition image. This configuration allows chips near the chip supply position to be included in the recognition target range while avoiding the range of the pickup unit's presence, and optimizes the positional relationship between the chip and the recognition target range based on the chip's size. As a result, the position of the chip can be appropriately recognized based on the captured image of the chip while suppressing the effects of distortion due to stretching of the sheet holding the chip and deviation of the chip relative to the camera field of view.

[0012] The image pickup control unit may be configured to set the recognition range to include two or more chips, thereby enabling the positions of two or more chips to be recognized efficiently in one image capture.

[0013] The chip pickup device may also be configured such that the imaging control unit adjusts the position of the wafer camera in the transport direction using the camera drive mechanism so that the center of the camera field of view coincides with the center of the recognition target range. With this configuration, it is possible to acquire images of the chips while effectively suppressing the influence of distortion caused by the chip being biased relative to the camera field of view.

[0014] The image pickup control unit may be configured to set the recognition target range upstream in the conveying direction from the range of the pickup unit when adsorbing the chip held on the sheet. In this configuration, the image of the chip can be captured before it is supplied to the chip supply position, and the position of the chip can be recognized in advance.

[0015] The imaging control unit may be configured to set the recognition target range for a predetermined number of chips adjacent to a blind spot overlapping chip, which is a chip that overlaps the blind spot of the pickup unit when adsorbing a chip held on a sheet, as viewed from the wafer camera. Such a configuration allows the recognition target range to be set as close as possible to the chip supply position.

[0016] The imaging control unit may be configured to set a recognition target range for a predetermined number of chips adjacent to the blind spot overlapping chip when chip recognition has been performed for all blind spot overlapping chips. In this configuration, the recognition target range can be set appropriately depending on the execution status of chip recognition for the blind spot overlapping chips.

[0017] Furthermore, the imaging control unit may be configured to configure the chip pickup device so that, when chip recognition has not been performed for at least some of the blind spot overlapping chips, the imaging control unit faces the wafer camera toward the blind spot overlapping chips for which chip recognition has not been performed, captures images of the blind spot overlapping chips with the wafer camera, and performs chip recognition for the blind spot overlapping chips. With this configuration, chip recognition can be reliably performed for the blind spot overlapping chips.

[0018] The chip pickup device may be configured so that the imaging control unit holds a limit number, which is the number of chips included in the recognition target range, and sets the size of the recognition target range according to the limit number and the size of the chip. In this configuration, by limiting the number of chips included in the recognition target range, it is possible to prevent chip recognition from being performed on chips for which the influence of sheet stretching before being supplied to the chip supply position cannot be ignored.

[0019] The chip pickup device may be configured so that the pickup unit picks up the chips held on the sheet and the wafer camera captures the images of the chips in the camera's field of view in parallel. In this configuration, the time required for the pickup unit to pick up the chips can be used to efficiently capture the images of the chips with the wafer camera.

[0020] According to the present invention, it is possible to acquire images of chips while suppressing the influence of distortion due to stretching of the sheet holding the chips and deviation of the chips relative to the camera field of view.

[0021] 5 is a diagram schematically showing the configuration and operation of a chip mounting device according to the present invention. FIG. 1 is a block diagram showing the electronic configuration of the chip mounting device of FIG. 1. FIG. 2 is a diagram schematically showing the operation performed in chip recognition using a recognition camera. FIG. 3 is a diagram schematically showing the operation performed in chip recognition using a recognition camera. FIG. 4 is a flowchart showing an example of chip recognition performed by a chip mounting device. FIG. 5 is a flowchart showing an example of chip pick-up performed in parallel with the chip recognition of FIG. 4. FIG. 6 is a diagram schematically showing the operation performed in accordance with the flowcharts of FIGS. 4 and 5 in a plan view from the Z direction. FIG. 7 is a diagram schematically showing a modified example of the setting mode of the chip recognition range.

[0022] Fig. 1 is a diagram schematically illustrating the configuration and operation of a chip mounting apparatus according to the present invention, and Fig. 2 is a block diagram illustrating the electrical configuration of the chip mounting apparatus of Fig. 1. Fig. 1 shows the horizontal X direction, the horizontal Y direction perpendicular to the X direction, and the vertical Z direction. The chip mounting apparatus 1 shown in Fig. 1 includes a chip pickup device 2 that sequentially picks up chips C from a wafer W composed of chips C arranged in a matrix in the X and Y directions, and a mounting head 11 that mounts the chips C picked up by the chip pickup device 2 on a mounting target such as a substrate. An integrated circuit is formed on the chip C.

[0023] The chip pickup device 2 includes a wafer stage 31 on which the wafer W is placed and a stage drive mechanism 33 that drives the wafer stage 31. Each chip C constituting the wafer W is attached to an adhesive sheet H, and a wafer ring that holds the periphery of the adhesive sheet H is placed on the wafer stage 31 and held by the wafer stage 31. The stage drive mechanism 33 includes an X-axis drive unit 331 that drives the wafer stage 31 in the X direction and a Y-axis drive unit 332 that drives the wafer stage 31 in the Y direction. Therefore, by driving the wafer stage 31 in the X direction with the X-axis drive unit 331, the chip C on the wafer stage 31 can be moved in the X direction, and by driving the wafer stage 31 in the Y direction with the Y-axis drive unit 332, the chip C on the wafer stage 31 can be moved in the Y direction. In particular, the X-axis drive unit 331 transports the wafer stage 31 in the X direction at a predetermined feed pitch Px, thereby supplying the chips C one by one to the chip supply position Ls. Here, the feed pitch Px corresponds to the pitch at which the chips C are arranged on the wafer W in the X direction.

[0024] The chip pickup device 2 includes a push-up member 41 that faces the chip supply position Ls from below, and a push-up drive unit 43 that drives the push-up member 41 in the Z direction. The push-up drive unit 43 raises and lowers the push-up member 41 between a push-up position where the upper end of the push-up member 41 pushes up the chip C at the chip supply position Ls via the adhesive sheet H, and a retracted position where the upper end of the push-up member 41 is separated downward from the adhesive sheet H.

[0025] The chip pickup device 2 also includes a head unit 5 that picks up chips C supplied to the chip supply position Ls. The head unit 5 has two pickup heads 51. These two pickup heads 51 have a common configuration except that they are located at different positions in the X direction. The pickup head 51 has a suction plate 52 at its tip, and the suction plate 52 has a suction surface 521 for suctioning chips C. That is, the suction surface 521 has multiple suction holes. When the suction surface 521 abuts against the chip C, the chip C is sucked onto the suction surface 521 by negative pressure generated in the suction holes. The pickup head 51 is also rotatable about a rotation axis 511 parallel to the Y direction. That is, the pickup head 51 rotates between a suction rotation position Lr1 where the suction surface 521 of the suction plate 52 faces downward and a reverse rotation position Lr2 where the suction surface 521 of the suction plate 52 faces upward.

[0026] The chip pickup device 2 includes a head unit drive mechanism 6 that drives the head unit 5. The head unit drive mechanism 6 has two head suction units 61 and two head rotation units 62 that correspond to the two pickup heads 51. The head suction units 61 apply negative pressure to suction holes that open in the suction surface 521 of the suction plate 52 of the corresponding pickup head 51, thereby adsorbing the chip C to the suction surface 521. The head rotation unit 62 drives the corresponding pickup head 51 between a suction rotation position Lr1 and a reverse rotation position Lr2. The head unit drive mechanism 6 also has an X-axis drive unit 631 that drives the head unit 5 in the X direction, a Y-axis drive unit 632 that drives the head unit 5 in the Y direction, and a Z-axis drive unit 633 that drives the head unit 5 in the Z direction.

[0027] The chip pickup device 2 also has a recognition camera 71 that captures an image of the chip C held on the wafer stage 31 from above, and a camera driver 72 that drives the recognition camera 71 in the X direction. Details of the recognition camera 71 and the camera driver 72 will be described later.

[0028] Furthermore, the chip mounting device 1 has a controller 9 that performs overall control of the entire chip mounting device 1. The controller 9 has a drive control unit 91 that controls the stage drive mechanism 33, the push-up drive unit 43, and the head unit drive mechanism 6, and an imaging control unit 92 that controls the recognition camera 71 and the camera drive unit 72.

[0029] 1, the drive control unit 91 controls the stage drive mechanism 33 to adjust the position of the wafer stage 31 in the X and Y directions to position one chip C at the chip supply position Ls, and controls the push-up drive unit 43 to position the push-up member 41 at the push-up position, thereby causing the push-up member 41 to push up the chip C at the chip supply position Ls. Furthermore, the drive control unit 91 controls each head rotation unit 62 to position one of the two pickup heads 51 at the pickup rotation position Lr1, while positioning the other pickup head 51 at the reverse rotation position Lr2.

[0030] Furthermore, as shown in the "Suction Operation" section of FIG. 1 , the drive control unit 91 controls the X-axis drive unit 631 and the Y-axis drive unit 632 of the head unit drive mechanism 6 to cause the suction surface 521 of the pickup head 51 at the suction rotation position Lr1 to face the chip C at the chip supply position Ls from above, and controls the Z-axis drive unit 633 of the head unit drive mechanism 6 to cause the suction surface 521 of the pickup head 51 at the suction rotation position Lr1 to abut against the chip C at the chip supply position Ls. Then, the drive control unit 91 controls the head suction unit 61 corresponding to the pickup head 51 at the suction rotation position Lr1 to suck the chip C onto the suction surface 521 abutting against the chip C. Note that when suction of the chip C is completed, the drive control unit 91 controls the push-up drive unit 43 to lower the push-up member 41 from the push-up position to the retracted position.

[0031] In particular, as will be described in detail later, the drive control unit 91 controls the position of the pickup head 51 in the X and Y directions relative to the chip C located at the chip supply position Ls based on the results of chip recognition that recognizes the position of the chip C to be adsorbed by the pickup head 51 before the chip C is supplied to the chip supply position Ls.

[0032] As shown in the "Inversion Operation" column of FIG. 1 , the drive control unit 91 controls the head rotation unit 62 corresponding to the pickup head 51 that has adsorbed the chip C by the adsorption surface 521, thereby rotating the pickup head 51 from the adsorption rotation position Lr1 to the inversion rotation position Lr2. In this way, the chip C is supported on the upward-facing adsorption surface 521. This causes the chip C to wait at the delivery position Ld. In parallel with the inversion operation of rotating the pickup head 51 from the adsorption rotation position Lr1 to the inversion rotation position Lr2, the drive control unit 91 controls the X-axis drive unit 331 of the stage drive mechanism 33 to move the wafer W in the X direction by the feed pitch Px, thereby supplying the chip C to the chip supply position Ls. However, the timing of supplying the chip C to the chip supply position Ls is not limited to this and may occur after the inversion operation is completed.

[0033] As shown in the "Delivery Operation" column of Fig. 1, the mounting head 11 of the chip mounting device 1 uses the nozzle at the tip of the mounting head 11 to pick up the chip C waiting at the delivery position Ld. At this time, the drive control unit 91 releases the suction of the chip C by the suction surface 521 of the pickup head 51 that keeps the chip C waiting at the delivery position Ld. Then, as shown in the "Transfer Operation" column of Fig. 1, the mounting head 11 transfers the chip C from the delivery position Ld to a mounting target such as a substrate.

[0034] 3A and 3B are diagrams schematically illustrating operations performed in chip recognition using a recognition camera. 3A shows the chip pickup device 2 as viewed from the front in the Y direction, and 3B shows the wafer W as viewed from the top in the Z direction. As shown in 3B, on the wafer W, a chip row CC is formed in which a plurality of chips C are aligned in a line in the X direction at a feed pitch Px, and a plurality of chip rows CC are aligned in the Y direction. The chip pickup device 2 sequentially supplies chips C from one chip row CC to a chip supply position Ls in order, starting with the most downstream (first) chip C in the X direction, and picks them up from the chip supply position Ls. Then, before supplying the chips C to the chip supply position Ls, chip recognition is performed on the chips C.

[0035] The recognition camera 71 has a lens 711 facing the chip C from above. The lens 711 forms an image of the recognition camera 71's camera field of view V71, which is then captured by a solid-state imaging device. The camera driver 72 is a single-axis robot that drives the recognition camera 71 in the X direction. Examples of such a single-axis robot include a ball screw and a linear motor. In particular, the imaging control unit 92 controls the X-direction position of the recognition camera 71 using the camera driver 72 to position the recognition camera 71 facing the target chip C from above, while causing the recognition camera 71 to capture an image. As a result, the recognition camera 71 captures an image of the chip C within the camera field of view V71 formed by the lens 711 using the solid-state imaging device, thereby acquiring an image of the chip C (chip recognition image Ir). The imaging control unit 92 then recognizes the position of the chip C in the X and Y directions based on the chip recognition image Ir representing the chip C (chip recognition).

[0036] 3A and 3B , the range of the suction plate 52 that suctions the chip C from the chip supply position Ls is shown as the range hidden by the suction plate 52 as viewed from the recognition camera 71, i.e., as a blind spot R52 of the suction plate 52. When the suction plate 52 has suctioned the chip C at the chip supply position Ls, the recognition camera 71 cannot capture an image of the entire chip C that overlaps the blind spot R52 (the chip C shown by the dashed line in FIG. 3B ). Here, of the multiple chips C lined up in a row in the X direction, including the chip C located at the chip supply position Ls, the chip C that overlaps the blind spot R52 is referred to as a blind spot overlapping chip Cd.

[0037] The imaging control unit 92 sets the chip recognition range Rr upstream of the blind spot R52 of the suction plate 52 in the X direction (chip transport direction). Specifically, the chip recognition range Rr is set to include N consecutive chips C adjacent to the blind spot overlapping chip Cd upstream of the blind spot overlapping chip Cd among the multiple chips C lined up in a row in the X direction, including the chip C located at the chip supply position Ls (i.e., the multiple chips C constituting one chip row CC). Here, "N consecutive chips C" refers to N chips C arranged consecutively in the X direction, where N is an integer greater than or equal to 2, and is 3 in the example of FIG. 3B. The width Xr of this chip recognition range Rr in the X direction satisfies the following relationship: N×Xc<Xr<(N+1)×Xc. Here, Xc is the width of the chip C in the X direction. In this way, a chip recognition range Rr is set for N (a predetermined number) chips C adjacent to the blind spot overlapping chip Cd. The chip recognition range Rr includes the entire N chips C, but does not include the entire blind spot overlapping chip Cd. Furthermore, in the X direction, the center of the chip recognition range Rr coincides with the center of the N chips C. Here, the centers of the N chips C are the centers of both ends of the chip group consisting of the N chips C in the X direction (in other words, the centers of one end of the chip C located at one end and the other end of the chip C located at the other end). The centers of the N chips C can be calculated, for example, from the chip supply position Ls, the width X52 of the blind spot R52, and the width Xc of the chip C. Note that in the X direction, the width of the gap between adjacent chips C can be ignored compared to the width Xc of the chip C.

[0038] Fig. 4 is a flowchart showing an example of chip recognition executed by the chip mounting device, Fig. 5 is a flowchart showing an example of chip pick-up executed in parallel with the chip recognition of Fig. 4, and Fig. 6 and Fig. 7 are diagrams schematically showing, in plan view from the Z direction, the operations executed in accordance with the flowcharts of Fig. 4 and Fig. 5. The flowcharts of Fig. 4 and Fig. 5 are executed under the control of the controller 9.

[0039] In step S101, the controller 9 controls the X-axis drive unit 631 and the Y-axis drive unit 632 via the drive control unit 91 to move the most downstream (i.e., the first) chip C in the X direction among the chips C belonging to the target chip row CC to the chip supply position Ls (the "S101" column in FIG. 6). In step S102, the controller 9 determines whether a parallel recognition condition is met. Here, the parallel recognition condition is a condition required for concurrently executing the suction operation of suctioning the chip C supplied to the chip supply position Ls with the suction plate 52 and the chip recognition of the chip C before being supplied to the chip supply position Ls (i.e., the chip C within the chip recognition range Rr).

[0040] This will be explained using FIG. 7. In FIG. 7, chips C for which chip recognition has already been performed are indicated by diagonal hatching, and chips C for which chip recognition has not yet been performed are indicated by white (similar notation is used in FIG. 6). As shown in the "Parallel Recognition Condition Satisfied" column of FIG. 7, if chip recognition has been performed on all blind-spot overlapping chips Cd that overlap the blind spot R52 of the suction plate 52 as seen from the recognition camera 71, it is determined that the parallel recognition condition is satisfied ("YES" in step S102). On the other hand, as shown in the "Parallel Recognition Condition Not Satisfied" column of FIG. 7, if chip recognition has not been performed on at least some blind-spot overlapping chips Cd that overlap the blind spot R52 of the suction plate 52 as seen from the recognition camera 71, it is determined that the parallel recognition condition is not satisfied ("NO" in step S102). 7, when the parallel recognition condition is satisfied, the following inequality holds for the number Q of chips C for which chip recognition has been performed: X52 / 2<(Q-1)×Xc+Xc / 2 When the parallel recognition condition is not satisfied, the following inequality holds: X52 / 2≧(Q-1)×Xc+Xc / 2 Note that the width of the gap between adjacent chips C in the X direction can be ignored compared to the width Xc of the chip C.

[0041] 6, when chip recognition is started and the leading chip C is moved to the chip supply position Ls, chip recognition has not been performed on any of the chips C. Therefore, in step S102, it is determined that the parallel recognition condition is not met (i.e., it is determined as "NO"), and the process proceeds to step S103.

[0042] In step 103, the controller 9 confirms that both pickup heads 51 are positioned at the inverted rotation position Lr2 and that the suction plate 52 of each pickup head 51 does not overlap (i.e., is retracted from) the chip supply position Ls. At this time, if the suction plate 52 overlaps the chip supply position Ls, the controller 9 controls the head rotation unit 62 by the drive control unit 91 to retract the suction plate 52 from the chip supply position Ls.

[0043] In step S104, the recognition camera 71 is directed to face all (four in this example) chips C (blind spot overlapping chips Cd) that overlap the blind spot R52. As a result, as shown in the "S104" column in Fig. 6, the center of the camera field of view V71 coincides with the center of all blind spot overlapping chips Cd that overlap the blind spot R52 (i.e., the center of the group of all blind spot overlapping chips Cd), and these blind spot overlapping chips Cd are included in the camera field of view V71.

[0044] In step S105, the controller 9 controls the recognition camera 71 by the imaging control unit 92 to capture images of each blind spot overlapping chip Cd within the camera field of view V71 and acquire a chip recognition image Ir. In step S106, the controller 9 causes the imaging control unit 92 to perform chip recognition to recognize the position (X, Y) of each blind spot overlapping chip Cd based on the chip recognition image Ir. As a result, chip recognition has been performed for each blind spot overlapping chip Cd.

[0045] After steps S104 to S106 are executed, the chip recognition has been executed for all the blind spot overlapping chips Cd that overlap the blind spot R52 of the suction plate 52 as seen from the recognition camera 71, so the parallel recognition condition is met ("YES" in step S102). Therefore, the process proceeds to step S107.

[0046] In step S107, the controller 9 causes the camera driving unit 72 to set the chip recognition range Rr. The specific method for setting this chip recognition range Rr is as described above with reference to FIG. 3B. As a result, as shown in the "S107" column in FIG. 6, the chip recognition range Rr is set so as to include N consecutive chips C (three chips) adjacent to the blind spot overlapping chip Cd upstream of the blind spot overlapping chip Cd that overlaps the blind spot R52, among the multiple chips C (multiple chips C constituting one chip row CC) lined up in the X direction, including the chip C located at the chip supply position Ls.

[0047] In step S108, the recognition camera 71 is made to face the chip recognition range Rr. As a result, as shown in the "S108" column in Fig. 6, the position of the camera field of view V71 is adjusted in the X and Y directions, the center of the camera field of view V71 coincides with the center of the chip recognition range Rr, and all of the chips C included in the chip recognition range Rr are included in the camera field of view V71.

[0048] In step S109, the controller 9 determines whether chip recognition has not been performed on all chips C included in the chip recognition range Rr. Here, the chips C included in the chip recognition range Rr refer to chips C whose entirety overlaps the chip recognition range Rr. As shown in the "S108" column in Figure 6, at this point, chip recognition has not been performed on all chips C included in the chip recognition range Rr, so the determination in step S109 is "YES" and the process proceeds to step S110.

[0049] In step S110, the controller 9 controls the recognition camera 71 using the imaging control unit 92 to capture images of the chips Cd included in the chip recognition range Rr within the camera field of view V71, thereby acquiring a chip recognition image Ir. Furthermore, in step S111, the controller 9 causes the imaging control unit 92 to perform chip recognition, which recognizes the position (X, Y) of each chip Cd within the chip recognition range Rr, based on the chip recognition image Ir. This completes chip recognition for each chip Cd within the chip recognition range Rr. Then, the process returns to step S109.

[0050] As shown in the "S109" column in FIG. 6, at this point, chip recognition has been performed on all chips C included in the chip recognition range Rr, so the determination in step S109 is "NO."

[0051] Incidentally, when the above-described step S106 is completed, the controller 9 has already performed chip recognition on the next chip C to be adsorbed, in other words, the chip C supplied to the chip supply position Ls. Therefore, the controller 9 determines "YES" in step S201 of chip pickup in Fig. 5. Then, based on the result of recognizing the position of the chip C at the chip supply position Ls, the drive control unit 91 controls the X-axis drive unit 631 and the Y-axis drive unit 632 to cause the suction surface 521 of the suction plate 52 of the head unit 5 located at the suction rotation position Lr1 to face the chip C at the chip supply position Ls (step S202).

[0052] Furthermore, the drive control unit 91 controls the head suction unit 61 to adsorb the chip C onto the adsorption surface 521 facing the chip C at the chip supply position Ls (step S203). The drive control unit 91 also rotates the pickup head 51, which adsorbs the chip C by the adsorption surface 521, from the adsorption rotation position Lr1 to the reverse rotation position Lr2, thereby moving the chip C to the delivery position Ld.

[0053] In response to the chips C being removed from the chip supply position Ls in steps S202 to S204, the drive control unit 91 transports the wafer W in the X direction by the feed pitch Px using the X-axis drive unit 331 (step S205), whereby the chips C adjacent to the chip supply position Ls in the X direction are supplied to the chip supply position Ls.

[0054] Such chip pickup in Fig. 5 is performed in parallel with chip recognition in Fig. 4. Therefore, while monitoring whether the condition in step S109 in Fig. 4 is satisfied, the wafer W is transported in the X direction by the feed pitch Px each time step S205 is performed. As a result, as shown in the columns "S205-1," "S205-2," and "S205-3" in Fig. 6, the number of chips C for which chip recognition has been performed decreases while the number of chips C for which chip recognition has not been performed increases in the chip recognition range Rr. Then, as shown in the column "S205-3" in Fig. 6, when all chips C included in the chip recognition range Rr become chips C for which chip recognition has not been performed, the determination in step S109 is "YES," and the process proceeds to step S110.

[0055] In step S110, the controller 9 controls the recognition camera 71 using the imaging control unit 92 to capture images of the chips Cd included in the chip recognition range Rr within the camera field of view V71, thereby acquiring a chip recognition image Ir. Furthermore, in step S111, the controller 9 causes the imaging control unit 92 to perform chip recognition, which recognizes the position (X, Y) of each chip Cd within the chip recognition range Rr, based on the chip recognition image Ir. This completes chip recognition for each chip Cd within the chip recognition range Rr. Then, the process returns to step S109.

[0056] In the embodiment described above, a wafer W including a plurality of chips C held on an adhesive sheet H (sheet) is transported in the X direction (transport direction) to supply the chips C to a chip supply position Ls. The chips C supplied to the chip supply position Ls are then pushed up by a push-up member 41 (push-up unit) via the adhesive sheet H. The chips C pushed up by the push-up member 41 and held on the adhesive sheet H are then adsorbed onto a suction plate 52 (pickup unit) of a pickup head 51 (head), and the suction plate 52 is then separated from the adhesive sheet H, thereby removing the chips C. Furthermore, the recognition camera 71 (wafer camera) captures an image of the chips C included in a camera field of view V71 of the wafer W. In particular, the position of the camera field of view V71 of the recognition camera 71, which captures the chips C, is adjusted in the X direction depending on the blind spot R52 (existence range) of the suction plate 52 of the pickup head 51 when adsorbing the chips C held on the adhesive sheet H and the width Xc (size) of the chips C in the X direction ( FIG. 3B , steps S107 and S108). This makes it possible to fit the chip C near the chip supply position Ls into the camera field of view V71 while avoiding the blind spot R52 of the suction plate 52, and to optimize the positional relationship between the chip C and the camera field of view V71 according to the width Xc of the chip C. As a result, it becomes possible to acquire a chip recognition image Ir of the chip C while suppressing the influence of distortion due to stretching of the adhesive sheet H that holds the chip C and deviation of the chip C relative to the camera field of view V71.

[0057] The system also includes an imaging control unit 92 (chip recognition unit) that performs chip recognition and recognizes the position of the chip C based on a chip recognition image Ir acquired by the recognition camera 71 capturing an image of the chip C. The imaging control unit 92 sets a chip recognition range Rr (recognition target range) in which the chip C to be recognized is located, based on a blind spot R52, which is the range within which the suction plate 52 exists when suctioning the chip C held on the adhesive sheet H, and the width Xc of the chip C in the X direction ( FIG. 3B , step S107). The imaging control unit 92 then adjusts the X-direction position of the wafer camera using the camera drive unit 72 (camera drive mechanism) so that the camera field of view V71 includes the chip recognition range Rr, and causes the recognition camera 71 to capture the chip recognition range Rr to acquire the chip recognition image Ir (steps S108 and S110). With this configuration, it is possible to fit the chip C near the chip supply position Ls into the chip recognition range Rr while avoiding the blind spot R52 of the suction plate 52, and to optimize the positional relationship between the chip C and the chip recognition range Rr according to the width Xc of the chip C. As a result, it is possible to appropriately recognize the position of the chip C based on the image of the chip C acquired while suppressing the influence of distortion due to stretching of the adhesive sheet H holding the chip C and deviation of the chip C relative to the camera field of view V71 (step S111).

[0058] Furthermore, the imaging control unit 92 sets the chip recognition range Rr so as to include two or more chips C (FIG. 3B, step S107). With this configuration, the positions of two or more chips C can be efficiently recognized by one imaging.

[0059] Furthermore, the imaging control unit 92 adjusts the position of the recognition camera 71 using the camera driving unit 72 so that the center of the camera field of view V71 coincides with the center of the chip recognition range Rr. With this configuration, it is possible to acquire a chip recognition image Ir of the chip C while effectively suppressing the influence of distortion caused by the deviation of the chip C relative to the camera field of view V71.

[0060] Furthermore, the imaging control unit 92 sets a chip recognition range Rr upstream in the X direction of the blind spot R52 of the suction plate 52 when suctioning the chip C held on the adhesive sheet H (FIG. 3B, step S107). In this configuration, the chip C is imaged before it is supplied to the chip supply position Ls, and the position of the chip C can be recognized in advance.

[0061] The imaging control unit 92 also sets a chip recognition range Rr for N (a predetermined number) chips C adjacent to the blind spot overlapping chips Cd, which are chips C that overlap the blind spot R52 of the suction plate 52 when suctioning the chips C held on the adhesive sheet H, as viewed from the recognition camera 71 (step S107). This configuration makes it possible to set the chip recognition range Rr as close as possible to the chip supply position Ls.

[0062] Furthermore, when chip recognition has been performed on all blind spot overlapping chips Cd ("YES" in step S102), the imaging control unit 92 sets a chip recognition range Rr for the N chips C adjacent to the blind spot overlapping chip Cd. In other words, the chip recognition range Rr is selectively set for the N chips C adjacent to the blind spot overlapping chip Cd, and the blind spot overlapping chip Cd is excluded from the target of the chip recognition range Rr. With this configuration, it is possible to appropriately set the recognition target range depending on the execution status of chip recognition for the blind spot overlapping chips.

[0063] Furthermore, if chip recognition has not been performed on at least some of the blind spot overlapping chips Cd (if "NO" in step S102d), the imaging control unit 92 faces the recognition camera 71 toward the blind spot overlapping chips Cd for which chip recognition has not been performed, captures an image of the blind spot overlapping chips Cd with the recognition camera 71, and performs chip recognition on the blind spot overlapping chips Cd (steps S104 to S106). With this configuration, chip recognition can be reliably performed on the blind spot overlapping chips Cd.

[0064] The imaging control unit 92 also holds a limit number (N) that is the number of chips C included in the chip recognition range Rr, and sets the width Xr of the chip recognition range Rr in accordance with the limit number (N) and the width Xc of the chip C ( FIG. 3B , step S107). In this configuration, by limiting the number of chips C included in the chip recognition range Rr to N, it is possible to prevent chip recognition from being performed on chips C for which the influence of stretching of the adhesive sheet H before they are supplied to the chip supply position Ls cannot be ignored (i.e., chips C far from the chip supply position Ls).

[0065] Furthermore, the suction of the chip C held on the adhesive sheet H by the suction plate 52 (step S203) and the image capture of the chip C included in the camera field of view V71 by the recognition camera 71 (step S110) are performed in parallel. In this configuration, the image capture of the chip C by the recognition camera 71 can be efficiently performed by utilizing at least a part of the time required for the suction plate 52 to suction the chip C.

[0066] As described above, in the above embodiment, the chip mounting device 1 corresponds to an example of the "chip mounting device" of the present invention, the mounting head 11 corresponds to an example of the "mounting section" of the present invention, the chip pickup device 2 corresponds to an example of the "chip pickup device" of the present invention, the wafer stage 31 corresponds to an example of the "wafer transport mechanism" of the present invention, the push-up member 41 corresponds to an example of the "push-up unit" of the present invention, the pickup head 51 corresponds to an example of the "head" of the present invention, the suction plate 52 corresponds to an example of the "pickup section" of the present invention, the recognition camera 71 corresponds to an example of the "wafer camera" of the present invention, the camera driving section 72 corresponds to an example of the "camera driving mechanism" of the present invention, the imaging control section 92 corresponds to an example of the "imaging control section" of the present invention, and the imaging control section 92 corresponds to an example of the "chip recognition section" of the present invention. ", chip C corresponds to an example of a "chip" of the present invention, blind spot overlapping chip Cd corresponds to an example of a "blind spot overlapping chip" of the present invention, adhesive sheet H corresponds to an example of a "sheet" of the present invention, chip recognition image Ir corresponds to an example of a "chip recognition image" of the present invention, chip supply position Ls corresponds to an example of a "chip supply position" of the present invention, N corresponds to an example of a "limited number" of the present invention, blind spot R52 corresponds to an example of a "pickup unit presence range" of the present invention, chip recognition range Rr corresponds to an example of a "recognition target range" of the present invention, camera field of view V71 corresponds to an example of a "camera field of view" of the present invention, wafer W corresponds to an example of a "wafer" of the present invention, the X direction corresponds to an example of a "transport direction" of the present invention, and width Xc of chip C corresponds to an example of a "chip size" of the present invention.

[0067] The present invention is not limited to the above embodiment, and various modifications can be made to the above without departing from the spirit of the present invention. For example, the number of chips C included in the chip recognition range Rr, i.e., N, is not limited to three, but may be any number equal to or greater than two. Furthermore, the chip recognition range Rr may be set to include a single chip C.

[0068] Furthermore, the chip C that is the target of chip recognition in steps S104 to S106 is not limited to the blind spot overlapping chip Cd described above. Therefore, the blind spot overlapping chip Cd and the chip C adjacent to the blind spot overlapping chip Cd may also be the target of chip recognition in steps S104 to S106. In this case, the chip recognition range Rr set in step S107 may be set to N consecutive chips adjacent to the target chip of chip recognition in steps S104 to S106.

[0069] Furthermore, the number N of chips C included in the chip recognition range Rr may be changed according to the width Xc in the X direction of the chip C. For example, the number of chips C included in the chip recognition range Rr may be increased as the width Xc of the chip C becomes shorter.

[0070] Furthermore, the number of pickup heads 51 provided in the head unit 5 is not limited to a plurality, and may be a single pickup head.

[0071] Furthermore, it is not essential that the center of the chip recognition range Rr that captures the camera field of view V71 coincides with the center of the camera field of view V71, and it does not matter if they are misaligned.

[0072] The size of the chip recognition range Rr set in step S107 may be changed as appropriate. In particular, the size of the chip recognition range Rr can be set as appropriate with respect to the chip concealment range Δ between the downstream end of the chip C located at the chip supply position Ls in the X direction and the upstream end of the blind spot R52 (i.e., the range in which the chip C is concealed by the blind spot R52).

[0073] FIG. 8 is a diagram showing a modified example of the setting of the chip recognition range. In the example of FIG. 6 above, the chip recognition range Rr is set to include three consecutive chips C adjacent to the blind spot overlapping chip Cd. As a result, the chip recognition range Rr is shorter than the chip hiding range Δ in the X direction. On the other hand, in the example of FIG. 8, the chip recognition range Rr is set to include eight consecutive chips C adjacent to the blind spot overlapping chip Cd. As a result, the chip recognition range Rr is longer than the chip hiding range Δ in the X direction.

[0074] REFERENCE SIGNS LIST 1...Chip mounting device 11...Mounting head (mounting section) 2...Chip pickup device 31...Wafer stage (wafer transport mechanism) 41...Push-up member (push-up unit) 51...Pick-up head (head) 52...Suction plate (pick-up section) 71...Recognition camera (wafer camera) 72...Camera drive section (camera drive mechanism) 92...Image capture control section (chip recognition section) C...Chip Cd...Blind spot overlapping chip H...Adhesive sheet (sheet) Ir...Chip recognition image Ls...Chip supply position N...Number of chips C (limited number) R52...Blind spot (existence range of pickup section) Rr...Chip recognition range V71...Camera field of view W...Wafer X...X direction (transport direction) Xc...Chip width (chip size)

Claims

1. A chip pickup device comprising: a wafer transport mechanism that transports a wafer including a plurality of chips held on a sheet in a predetermined transport direction to supply the chips to a chip supply position; a push-up unit that pushes up the chips supplied to the chip supply position through the sheet; a head having a pickup section that adsorbs the chips, the chips pushed up by the push-up unit and held on the sheet being adsorbed to the pickup section, and then removing the chips by moving the pickup section away from the sheet; a wafer camera having a camera field of view that captures images of the chips on the wafer that are included in the camera field of view; a camera drive mechanism that drives the wafer camera in the transport direction; and an imaging control section that controls the camera drive mechanism to adjust the position of the camera field of view of the wafer camera that images the chips in the transport direction in accordance with the range of the pickup section when adsorbing the chips held on the sheet and the size of the chips in the transport direction.

2. A chip pickup device as described in claim 1, further comprising a chip recognition unit that performs chip recognition to recognize the position of the chip based on a chip recognition image acquired by the wafer camera by capturing an image of the chip, wherein the imaging control unit sets a recognition target range in which the chip to be subject to chip recognition is located according to the range of existence of the pickup unit when adsorbing the chip held on the sheet and the size of the chip in the transport direction, adjusts the position of the wafer camera in the transport direction by the camera drive mechanism so that the camera field of view includes the recognition target range, and causes the wafer camera to capture an image of the recognition target range to obtain the chip recognition image.

3. The chip pickup device according to claim 2, wherein the imaging control section sets the recognition target range so as to include two or more of the chips.

4. A chip pickup device as described in claim 2 or 3, wherein the imaging control unit adjusts the position of the wafer camera in the transport direction by the camera driving mechanism so that the center of the camera field of view coincides with the center of the recognition target range.

5. A chip pickup device as described in any one of claims 2 to 4, wherein the imaging control unit sets the recognition target range upstream in the conveying direction of the range in which the pickup unit exists when adsorbing the chip held on the sheet.

6. The chip pickup device described in claim 5, wherein the imaging control unit sets the recognition target range for a predetermined number of chips adjacent to a blind spot overlapping chip, which is a chip that, as viewed from the wafer camera, overlaps with the blind spot of the pickup unit when adsorbing the chip held on the sheet.

7. The chip pickup device of claim 6, wherein the imaging control unit sets the recognition target range for the predetermined number of chips adjacent to the blind spot overlapping chip when the chip recognition has been performed for all of the blind spot overlapping chips.

8. The chip pickup device of claim 6 or 7, wherein when the chip recognition has not been performed for at least some of the blind spot overlapping chips, the imaging control unit faces the wafer camera toward the blind spot overlapping chips for which the chip recognition has not been performed, images the blind spot overlapping chips using the wafer camera, and performs the chip recognition for the blind spot overlapping chips.

9. A chip pickup device as described in any one of claims 2 to 8, wherein the imaging control unit holds a limit number which is the number of chips included in the recognition target range, and sets the size of the recognition target range according to the limit number and the size of the chip.

10. A chip pickup device as described in any one of claims 1 to 9, wherein the pickup section picks up the chip held on the sheet and the wafer camera captures an image of the chip included in the camera field of view in parallel.

11. A chip mounting device comprising: the chip pickup device according to any one of claims 1 to 10; and a mounting section that mounts the chip picked up by the chip pickup device on an object to be mounted.

12. A chip pick-up method comprising the steps of: transporting a wafer including a plurality of chips held on a sheet in a predetermined transport direction to supply the chips to a chip supply position; pushing up the chips supplied to the chip supply position through the sheet with a push-up unit; adsorbing the chips pushed up by the push-up unit and held on the sheet to a pick-up section of a head, and then moving the pick-up section away from the sheet to remove the chips; adjusting the position of a camera field of view of a wafer camera that images the chips in the transport direction depending on the range of the pick-up section when adsorbing the chips held on the sheet and the size of the chips in the transport direction; and imaging the chips of the wafer included in the camera field of view with the wafer camera.

Images