Die pick-up method and device

Abstract

The movement of an imaging part that images a produced die, the recognition of a produced die, and the suctioning of a good die by using a head on the basis of the result of the recognition are performed in a reference order corresponding to a wafer map, and the pickup of a good die is performed. When the imaging part moves via an upper side of a mirror die according to the reference order, the distance of the movement may exceed an allowable movement amount. In such a case, the order of at least a portion among the movement of the imaging part, and the recognition and suctioning of the produced die is changed from the reference order. Accordingly, the movement distance is suppressed to the allowable movement amount or less at all times. Consequently, map misalignment can be prevented, and a good die can be accurately picked up from a wafer including a mirror die.

Description

[Technical field]

[0001] The present invention relates to a die pick-up method and apparatus for picking up a non-defective die from a diced wafer. [Background technology]

[0002] A component mounting apparatus is known that picks up a die (bare chip) as a component from a diced wafer and mounts it on a substrate. This component mounting apparatus has a built-in die pickup device that picks up the die. This die pickup device includes a head that can pick up the die individually, a camera that captures the die, and a control unit that controls the operation of the head and the camera. The control unit moves the camera above a good die to be picked up next based on a wafer map that is created in advance for the wafer to be picked up and indicates whether each die is good or bad (movement process). Then, the control unit recognizes the position of the good die from the image of the good die captured by the camera (recognition process). Based on the recognition result, the control unit controls the head to move above the target good die and pick it up (suction process). In this way, in order to pick up multiple dies designated as "good dies" in the wafer map, the movement process, recognition process, and suction process are performed for each good die. The order of these processes is performed according to the wafer map, and is referred to as a "reference order" in this specification. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7008124 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, a wafer may contain a so-called mirror die area, in which a plurality of bare chips (mirror dies) on which no pattern is formed are consecutively formed during wafer fabrication. In this case, a wafer map is created taking the mirror die area into consideration. Then, when the above-mentioned series of operations (=movement process + recognition process + suction process) are performed in a reference sequence corresponding to the wafer map, the following problem may occur. For example, a mirror die area (hatched area MR in FIG. 3) may exist between two good dies (e.g., good dies A and G in FIG. 3) that are consecutively picked up according to the reference sequence (dash-dotted line in FIG. 3, which will be described later). In this case, the camera moves toward the next good die via above the mirror die area. Therefore, the distance traveled without performing the recognition process becomes long, causing a map shift (a position shift between the die position on the wafer map and the die position on the actual wafer), which may cause an inconvenience in that the desired good die cannot be picked up.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a die pickup method and apparatus that can accurately pick up good dies from a wafer including mirror dies on which no patterns are formed. [Means for solving the problem]

[0006] A first aspect of the present invention is a die pickup method for sequentially picking up good dies on a wafer having a production die on which a pattern is formed and a mirror die on which a pattern is not formed, by referring to a wafer map that is created in advance to indicate the quality of each of the production dies, and for each good die among the production dies, moving an imaging unit that images the production die, recognizing the production die, and picking up the good die by a head based on the results of the recognition, the method comprising: (a) a step of storing an order of movement of the imaging unit according to the wafer map, recognition of the production die, and picking up the good die by a head based on the results of the recognition, (b) a step of determining, for each movement of the imaging unit that passes above the mirror die among the movements of the imaging unit according to the standard order, whether or not the movement distance of the imaging unit exceeds an allowable movement amount required to keep the map deviation amount after the movement within an allowable value, and (c) a step of limiting the movement distance to within the allowable movement amount in step (b), by changing the order of at least a part of the movement of the imaging unit, recognition of the production die, and picking up the good die from the standard order.

[0007] In addition, a second aspect of the present invention is a die pickup device that picks up good dies from the production dies from a wafer having a production die on which a pattern is formed and a mirror die on which a pattern is not formed, the die pickup device comprising: an imaging unit that images the production die; a head that picks up the good dies; a moving unit that moves the imaging unit and the head above the wafer; a memory unit that stores an order of movement of the imaging unit according to a wafer map that is created in advance to indicate the quality of each of the production dies, and recognition and pickup of the production dies as a reference order; and a control unit that controls the head and the imaging unit, wherein the control unit has a movement distance determination unit that determines, for each movement of the imaging unit that passes above the mirror die among the movements of the imaging unit according to the reference order, whether the movement distance of the imaging unit exceeds an allowable movement amount required for keeping the map deviation amount after the movement within an allowable value; and, when it is determined that the movement distance exceeds the allowable movement amount, an order change unit that changes the order of at least a part of the movement of the imaging unit, the recognition of the production dies, and pickup from the reference order to keep the movement distance within the allowable movement amount.

[0008] In the invention configured in this way, the movement of the imaging unit, the recognition of the produced die, and the suction are basically performed in a standard sequence corresponding to the wafer map. This allows the pickup of a non-defective die. However, when the imaging unit moves above the mirror die in accordance with the standard sequence, the movement distance may exceed the allowable movement amount. This may cause the map deviation amount to exceed the allowable value, resulting in an inconvenience in which the recognition of the produced die cannot be performed appropriately. Therefore, in the present invention, when the movement distance exceeds the allowable movement amount, at least a part of the order of the movement of the imaging unit, the recognition of the produced die, and the suction is changed from the standard sequence. As a result, the movement distance is always kept below the allowable movement amount.

[0009] The mirror die is formed, for example, at the periphery or center of the wafer. Therefore, there are three patterns in which a map shift occurs when the imaging unit moves above the mirror die according to the reference sequence. First occurrence pattern: A mirror die area in which multiple mirror dies are formed continuously is provided along the latter half of the return path along which the imaging unit moves from the center of the wafer to the periphery according to the reference sequence, and a map deviation occurs when the imaging unit moves above the mirror die area. Second occurrence pattern: A mirror die area in which multiple mirror dies are formed continuously is provided along the first half of the return path along which the imaging unit moves from the center of the wafer to the periphery according to the reference sequence, and a map deviation occurs when the imaging unit moves above the mirror die area. Third occurrence pattern: A mirror die area in which multiple mirror dies are formed continuously is provided along a central path along which the imaging unit moves to the center of the wafer in accordance with the reference sequence, and a map deviation occurs when the imaging unit moves above the mirror die area. exists.

[0010] Here, in the first occurrence pattern, the moving distance in step (b) may be the distance between the first good die that is picked up just before the imaging unit moves to the mirror die area according to the reference sequence, and the second good die that is picked up just after the imaging unit passes through the mirror die area, and step (c) may include a step of changing the order of the movement of the imaging unit, the recognition of the produced die, and the pickup in the first half of the turn-back path as a change in the reference sequence (c-1). This reduces the moving distance of the imaging unit above the second good die from the point when the first half of the turn-back path is completed, and keeps it below the allowable moving amount.

[0011] As a specific modification, for example, when multiple good dies existing along the first half of the turn-back path and adjacent to the mirror die area are the change target dies, the step (c-1) may include the steps of (c-1-1) moving the imaging unit to the peripheral portion of the wafer along the first half of the turn-back path prior to recognizing and picking up the change target die, thereby positioning the imaging unit above the change target die that is closest to the turn-back position among the multiple change target dies, (c-1-2) performing recognition and pick-up after the step (c-1-1), and (c-1-3) moving the imaging unit and recognizing and picking up the change target die on a path opposite to the first half of the turn-back path following the step (c-1-2). This minimizes the distance from above the last good die among the change target dies to above the second good die, i.e., the distance that the imaging unit moves via above the mirror die area, and is reliably kept below the allowable movement amount.

[0012] When the step (c-1-1) is configured to include a step of moving and recognizing the imaging unit at least once by the allowable movement amount, the number of times that the imaging unit is moved and recognized without adsorption is reduced, thereby shortening the time required for die pickup.

[0013] In the second generation pattern, the moving distance of the imaging unit in step (b) may be set to the distance between the first non-defective die that is picked up just before the imaging unit moves to the mirror die area according to the reference sequence, and the second non-defective die that is picked up just after the imaging unit passes through the mirror die area, and step (c) may include a step of changing the order of movement and recognition of the imaging unit in the first half of the turn-back path as a change in the reference sequence (c-2). This reliably limits the distance that the imaging unit moves above the mirror die area in the first half of the turn-back path to within the allowable movement amount.

[0014] As a specific modification, for example, when multiple good dies adjacent to a mirror die area existing along the latter half of the turn-back path are the change target dies, the step (c-2) may include the steps of: (c-2-1) moving the imaging unit to the peripheral portion of the wafer along a path opposite to the latter half of the turn-back path to position the imaging unit above the change target die that is closest to the turn-back position among the multiple change target dies; (c-2-2) performing recognition and suction after the step (c-2-1); and (c-2-3) moving the imaging unit and performing recognition and suction of the change target die in the latter half of the turn-back path following the step (c-2-2). This minimizes the distance from the first good die to the top of the change target dies, i.e., the distance that the imaging unit moves via the mirror die area, and is reliably kept below the allowable movement amount.

[0015] If the step (c-2-1) includes a step of moving and recognizing the imaging unit at least once by the allowable movement amount, the number of times that the imaging unit is moved and recognized without adsorption is reduced, thereby shortening the time required for die pickup.

[0016] Furthermore, in a third occurrence pattern, the movement distance of the imaging unit in step (b) may be set to the distance between the first pass die that is picked up just before the imaging unit moves to the mirror die area according to the reference order and the second pass die that is picked up just after the imaging unit passes through the mirror die area, and step (c) may include a step (c-3) of changing the reference order, in which the imaging unit moves along a detour path from the first pass die to the second pass die via the periphery of the mirror die area, thereby limiting the movement distance of the imaging unit that passes above the mirror die area to within the allowable movement amount.

[0017] If the step (c-3) includes a step of moving and recognizing the imaging unit at least once by the allowable movement amount, the number of times that the imaging unit is moved and recognized without adsorption is reduced, thereby shortening the time required for die pickup. Effect of the Invention

[0018] As described above, according to the present invention, good dies can be accurately picked up from a wafer including mirror dies on which no patterns are formed. [Brief description of the drawings]

[0019] [Figure 1] 1 is a plan view showing a schematic diagram of an example of a component mounter equipped with a die pickup device according to a first embodiment of the present invention. [Diagram 2] 2 is a block diagram showing an electrical configuration of the component mounter of FIG. 1. [Diagram 3] FIG. 1 is a diagram illustrating a first occurrence pattern of map deviation that occurs in the prior art. [Figure 4] FIG. 11 is a diagram illustrating a second occurrence pattern of map deviation that occurs in the prior art. [Diagram 5] FIG. 11 is a diagram illustrating a third occurrence pattern of map deviation occurring in the prior art. [Figure 6A]FIG. 11 is a diagram illustrating a map deviation eliminating method in a first occurrence pattern. [Figure 6B] FIG. 11 is a diagram illustrating a map deviation eliminating method in a first occurrence pattern. [Figure 7A] FIG. 11 is a diagram illustrating a map deviation eliminating method in a second occurrence pattern. [Figure 7B] FIG. 11 is a diagram illustrating a map deviation eliminating method in a second occurrence pattern. [Figure 8A] FIG. 13 is a diagram illustrating a map deviation eliminating method in a third occurrence pattern. [Figure 8B] FIG. 13 is a diagram illustrating a map deviation eliminating method in a third occurrence pattern. [Figure 9] 4 is a flowchart showing a pickup operation of a non-defective die in the mounter shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] <Component mounter> Fig. 1 is a plan view showing a schematic diagram of an example of a component mounter equipped with a first embodiment of a die pickup device according to the present invention. Fig. 2 is a block diagram showing an electrical configuration of the component mounter of Fig. 1. As shown in Fig. 1, in this specification, XYZ orthogonal coordinate axes consisting of a conveying direction X, a width direction Y, and a vertical direction Z are appropriately used. The conveying direction X and the width direction Y are parallel to the horizontal direction and perpendicular to each other, and the vertical direction Z is perpendicular to the conveying direction X and the width direction Y.

[0021] This component mounter 10 mounts components Wp on a board 1 carried in from the upstream side in the transport direction X, and carries it out to the downstream side in the transport direction X. A plurality of mounting target points 1a are provided on the top surface of the board 1, and a control unit 100 provided in the component mounter 10 controls each unit of the component mounter 10 to mount components Wp on each mounting target point 1a.

[0022] As shown in FIG. 2, the control unit 100 has an arithmetic unit 110, which is a processor that handles the calculation functions for controlling the entire component mounter 10, an image processing unit 120 that handles image processing based on commands from the arithmetic unit 110, and a drive control unit 130 that controls drive mechanisms such as motors based on commands from the arithmetic unit 110. The control unit 100 also has a memory unit 140 that is configured with an HDD (Hard Disk Drive) or the like. This memory unit 140 stores a component mounting program 150 that includes a program (hereinafter referred to as a "pickup program") for causing the arithmetic unit 110 to execute a die pickup, which will be described later, and a wafer map 160. The component mounting program 150 can be stored on a DVD (Digital Versatile Disc) or a USB (Universal USB), for example. The component mounting program 150 is provided by being recorded on a recording medium 170 such as a USB Serial Bus, and the calculation unit 110 reads out the component mounting program 150 from the recording medium 170 and stores it in the storage unit 140. Note that the form in which the component mounting program 150 is provided is not limited to this, and the component mounting program 150 may be provided, for example, in a form in which it is downloaded from an Internet server.

[0023] A display unit 180 (e.g., a display) that displays various information and an input unit 190 (e.g., a keyboard and a mouse) that accepts input from an operator are connected to the control unit 100. Note that, for example, a touch panel display that combines the functions of the display unit 180 and the input unit 190 may be used.

[0024] The wafer map 160 is file data created in advance for each wafer W and associated with the management number of each wafer W, and is stored in the storage unit 140. As described in Patent Document 1, the wafer W has a plurality of dies (bare chips) that are separated by dicing. The dies are arranged in a matrix in the XY direction on the wafer sheet. These dies are so-called production dies that are produced so as to form a desired pattern, but some of the production dies are defective. Therefore, the position of each of these production dies is managed by an address based on the XY coordinate system. That is, each production die is evaluated as to whether it is a good product or a defective product based on a predetermined standard. Then, in the wafer map 160, the evaluation value of each production die is described in association with the address of the production die. Also, a good die (hereinafter referred to as a "good die") is picked up, and is picked up in a standard order according to the wafer map 160 by the component mounter 10 configured to be described next. Then, the component mounter 10 mounts the die on the substrate 1.

[0025] This component mounter 10 includes a transport unit 2 that transports a board 1 in a transport direction X. This transport unit 2 has two mounting work positions 21 aligned in the transport direction X, and transports the board 1 from the upstream side of the transport direction X to each mounting work position 21. In addition, the transport unit 2 transports the board 1, on which components Wp have been mounted at each mounting work position 21, from each mounting work position 21 to the downstream side of the transport direction X.

[0026] The component mounter 10 also includes a component supply mechanism 3 that supplies components Wp. This component supply mechanism 3 corresponds to a first embodiment of the die pickup device according to the present invention. In this component supply mechanism 3, only non-defective dies among the production dies of the diced wafer W are picked up as the components Wp. More specifically, the component supply mechanism 3 has a wafer storage section 31 that can store multiple wafers W, and a wafer pull-out section 33 that pulls out the wafer W from the wafer storage section 31 to the component supply position 32. The wafer storage section 31 can position one wafer holder Wh at a height where the wafer pull-out section 33 can receive the wafer W by raising and lowering a rack that stores multiple wafer holders Wh, each holding a wafer W, in the vertical direction Z, in the vertical direction Z, so that the wafer pull-out section 33 can receive the wafer W and push out the wafer holder Wh to the wafer pull-out section 33.

[0027] The wafer pull-out section 33 includes a wafer support table 331 that supports the wafer holder Wh, a fixed rail 332 that supports the wafer support table 331 movably in the width direction Y, a ball screw 333 that is provided in the width direction Y and attached to the wafer support table 331, and a Y-axis motor 334 that drives the ball screw 333. Therefore, by rotating the ball screw 333 by the Y-axis motor 334, the wafer support table 331 can be moved in the width direction Y along the fixed rail 332. As shown in FIG. 1, the wafer storage section 31 and the component supply position 32 are disposed so as to sandwich the transport section 2 in the width direction Y, and the wafer support table 331 passes below the transport section 2. The wafer support table 331 receives the wafer holder Wh from the wafer storage section 31 at a receiving position adjacent to the wafer storage section 31, and moves from the receiving position to the component supply position 32 to pull out the wafer W to the component supply position 32.

[0028] Furthermore, the component supply mechanism 3 has a component take-out unit 35 that takes out the component Wp from the component supply position 32. The component take-out unit 35 has a take-out head 36 that takes out the component Wp from the component supply position 32, and this take-out head 36 is movable in the XY direction. That is, the component take-out unit 35 has a support member 351 that supports the take-out head 36 movably in the conveying direction X, and an X-axis motor 352 that is provided in the conveying direction X and drives a ball screw attached to the take-out head 36. Therefore, the drive control unit 130 can move the take-out head 36 in the conveying direction X by rotating the X-axis motor 352. In addition, the component take-out unit 35 has a fixed rail 353 that supports the support member 351 movably in the width direction Y, a ball screw 354 that is provided in the width direction Y and attached to the fixed rail 353, and a Y-axis motor 355 that drives the ball screw 354. Therefore, the drive control unit 130 can move the take-out head 36 in the width direction Y together with the support member 351 by rotating the Y-axis motor 355.

[0029] The take-out head 36 has a bracket 361 extending in the conveying direction X, and two nozzles 362 rotatably supported by the bracket 361. Each nozzle 362 rotates about a rotation axis parallel to the conveying direction X, and is positioned at either a suction position facing downward or a delivery position facing upward (the position in FIG. 1). The bracket 361 can be raised and lowered together with each nozzle 362.

[0030] Furthermore, the component take-out unit 35 has a moving camera 356 that captures an image of the component Wp at the component supply position 32 from above using an image sensor, and this moving camera 356 is movable in the XY directions. That is, in the component take-out unit 35, the moving camera 356 is supported by the support member 351 so as to be movable in the conveying direction X. Furthermore, the component take-out unit 35 has an X-axis motor 357 that is provided in the conveying direction X and drives a ball screw attached to the moving camera 356. Therefore, the drive control unit 130 can move the moving camera 356 in the conveying direction X by rotating the X-axis motor 357, and can move the moving camera 356 together with the support member 351 in the width direction Y by rotating the Y-axis motor 355.

[0031] In the component supply mechanism 3, the following steps of (1) movement, (2) recognition, and (3) suction are repeated to continuously supply components Wp. (1) Movement: The drive control unit 130 moves the moving camera 356 above the part Wp to be supplied among the multiple parts Wp at the part supply position 32. (2) Recognition: The moving camera 356 captures an image of the part Wp and transfers the captured image to the image processing unit 120, which then recognizes the position of the part Wp from the captured image. (3) Pick-up: The drive control unit 130 drives the nozzle 362 based on the recognition result by the image processing unit 120, and when the nozzle 362 located at the pick-up position faces the component Wp from above, the drive control unit 130 lowers the nozzle 362 to contact the component Wp. Furthermore, the drive control unit 130 applies negative pressure to the nozzle 362 while raising the nozzle 362, thereby picking up the component Wp from the component supply position 32. Then, the drive control unit 130 positions the nozzle 362 at the delivery position to supply the component Wp.

[0032] The component mounter 10 includes two mounting units 4 that mount the components Wp thus supplied by the component supply mechanism 3 on the board 1. These two mounting units 4 are provided in a one-to-one correspondence with the two mounting work positions 21. Each mounting unit 4 includes a support member 41 that is movable along a fixed rail provided on the ceiling of the component mounter 10 in the width direction Y, and a mounting head 42 that is supported by the support member 41 so as to be movable in the transport direction X. Further, an X-axis motor 43 that drives a ball screw provided in the transport direction X and attached to the mounting head 42, and a Y-axis motor 44 that is provided in the width direction Y and attached to the support member 41 are provided. Therefore, the drive control unit 130 can move the mounting head 42 in the transport direction X by rotating the X-axis motor 43, and can move the mounting head 42 in the width direction Y along with the support member 41 by rotating the Y-axis motor 44.

[0033] When picking up the component Wp, the mounting heads 42 of the mounting units 4A and 4B move above the take-out head 36, bring the nozzle 421 from above to face the component Wp held by the nozzle 362 located at the delivery position, and then lower the nozzle 421 to contact the component Wp. Next, the component supply mechanism 3 releases the negative pressure on the nozzle 362, and the mounting units 4A and 4B apply negative pressure to the nozzle 421, causing the nozzle 421 to adsorb the component Wp, and then raise the nozzle 421 while applying the negative pressure. In this way, the mounting heads 42 pick up the component Wp with the nozzle 421.

[0034] The component supply mechanism 3 has two nozzles 362, and can supply two components Wp simultaneously using these nozzles 362. On the other hand, the mounting head 42 has two nozzles 421 corresponding to the two nozzles 362 of the component supply mechanism 3, and can simultaneously pick up the two components Wp supplied by the component supply mechanism 3 using the two nozzles 421. However, it is not essential to simultaneously supply and pick up two components Wp.

[0035] Furthermore, each mounting unit 4 has a movable camera 45 that is provided facing downward. The movable camera 45 captures images of the components Wp supplied by the component supply mechanism 3 and the components Wp mounted on the board 1 from above using an image sensor. This movable camera 45 is attached to the mounting head 42, and the drive control unit 130 can move the movable camera 45 in the XY directions in the same way as the mounting head 42 by rotating the X-axis motor 43 and the Y-axis motor 44.

[0036] The component mounter 10 also includes a fixed camera 5 provided for each mounting unit 4. The fixed camera 5 faces upward and is fixed to a base, and captures an image of a component Wp located above from below using an image sensor, as described below. In this way, the component mounter 10 configures an imaging unit including the movable camera 45, the fixed camera 5, and the movable camera 356.

[0037] In the component mounter 10 configured as described above, the calculation unit 110 controls each unit of the device according to the component mounting program 150 stored in the storage unit 140, thereby mounting good components Wp at each mounting target point 1a on the board 1 using one wafer W. The basic operation is the same as that of the device described in Patent Document 1, except for the map deviation suppression operation described next. Therefore, the map deviation suppression operation will be mainly described, and the same operations will not be described.

[0038] In one wafer W, a plurality of production dies (= good dies + defective dies) with a desired pattern are arranged in a lattice pattern in the XY direction. Then, as described in Patent Document 1, for example, among the production dies arranged in one row in the X direction, good dies are sequentially picked up in the (-X) direction as the above-mentioned parts Wp. Next, a new line is started in the (+Y) direction at the end of the (-X) direction, and good dies among the production dies arranged in the next row in the X direction are sequentially picked up as the above-mentioned parts Wp from the (-X) direction to the (+X) direction. Furthermore, a new line is started in the (+Y) direction at the end of the (+X) direction, and good dies among the production dies arranged in the next row in the X direction are sequentially picked up as the above-mentioned parts Wp from the (+X) direction to the (-X) direction. In this way, the direction of pickup is reversed for each row, and the pickup operation is performed along a zigzag path. This pickup operation is performed while referring to the wafer map 160, and the order corresponds to an example of the "reference order" of the present invention.

[0039] The wafer map 160 includes information on mirror dies in addition to the pass / fail evaluation of each die fabricated on the wafer W as described above. A pattern is not formed on this mirror die, and it is distinguished from a production die. Coordinates between the wafer W and the wafer map are aligned based on the address of the mirror die. Here, a plurality of mirror dies are gathered on the wafer W in order to easily distinguish the mirror dies from defective dies that generally occur in a dispersed manner, one by one. In the present invention, the area where a plurality of mirror dies are gathered in this way is called a "mirror die area."

[0040] The mirror die regions are distributed on the surface of the wafer W. For example, as shown in FIGS. 3 to 5, the mirror die regions MR are often provided on the periphery or center of the wafer W. Here, when the moving camera 356 is moved according to the reference sequence, the moving camera 356 may move via above the mirror die regions MR. In this case, the moving distance becomes long without performing the above recognition, and a map deviation may occur. Therefore, the following describes the occurrence patterns of the map deviation and the method of eliminating them in order.

[0041] <Map deviation occurrence pattern> 3 to 5 are diagrams showing a typical pattern of map deviations that occurred in the prior art. The mirror die regions MR are distributed on the surface of the wafer W. More specifically, the mirror die regions MR are provided in the peripheral portion of the wafer W (FIGS. 3 and 4) and the central portion of the wafer W (FIG. 5). In addition, in FIG. 3 to FIG. 5 (and FIG. 6A, FIG. 6B, FIG. 7A, FIG. 7B, FIG. 8A, and FIG. 8B described later), the dashed line indicates the reference order RO. In addition, the black triangle marks indicate good dies that have been picked up, the right-facing triangle marks indicate that the pickup is proceeding from the (-X) direction side to the (+X) direction side, and the left-facing triangle marks indicate that the pickup is proceeding from the (+X) direction side to the (-X) direction side. In addition, the black star marks indicate good dies that are currently being picked up. In addition, the square marks indicate good dies in which map deviations have occurred. In addition, the hatched areas indicate the mirror die regions MR. Also, the symbols A to Q indicate the respective production dies. Furthermore, the vertical axis indicates time, and the die pickup operations at each timing T11, T12, . . . are diagrammatically shown.

[0042] When die pickup is performed continuously in the reference order RO as in the conventional technology, the moving camera 356 moves to above the next good die via above the mirror die area MR. This results in a long distance to move without performing recognition processing, which may cause map deviation (deviation between the die position on the wafer map 160 in the XY plane and the die position on the actual wafer W), resulting in the inconvenience of not being able to pick up the desired good die. Three typical occurrence patterns are shown in Figures 3 to 5, respectively.

[0043] <<First occurrence pattern>> The first occurrence pattern occurs near the periphery of the wafer W, as shown in FIG. 3. In this occurrence pattern, a mirror die area MR in which a plurality of mirror dies MD are formed continuously is provided along the latter half P2 of the turn-back path RP that moves from the center of the wafer W to the periphery. For this reason, in the first half P1 of the turn-back path RP, die pickup (=(1) movement + (2) recognition + (3) suction) is performed in the order of good dies F, E, D, C, B, and A (timing T11-T12). After that, the moving camera 356 moves linearly from above the good die A (corresponding to an example of the "first good die" of the present invention) to above the next good die G (corresponding to an example of the "second good die" of the present invention) (timing T13). That is, the moving camera 356 moves above the mirror die area MR. If the distance of the moving camera 356 at this time exceeds the allowable movement amount (symbol MMP in FIG. 9), a map deviation occurs in the good die G, as shown in the bottom part of FIG. 3.

[0044] In this specification, the mirror dies MD are continuous to such an extent that the movement distance of the moving camera 356 along the second half P2 of the turn-back path RP exceeds the allowable movement amount, which is referred to as the second half continuous condition. When this second half continuous condition is satisfied, as shown in Figures 6A and 6B, it is possible to suppress the movement of the moving camera 356 to the allowable movement amount or less by changing at least a part of the order of the movement of the moving camera 356, the recognition of the produced die, and the suction from the reference order RO. This makes it possible to eliminate the map deviation. This point will be described later with reference to Figures 6A and 6B.

[0045] <<Second occurrence pattern>> The second occurrence pattern occurs near the periphery of the wafer W, as shown in FIG. 4. In this occurrence pattern, a mirror die region MR in which a plurality of mirror dies MD are formed continuously is provided along the first half P1 of the turn-back path RP that moves from the center of the wafer W to the periphery. For this reason, in the first half P1 of the turn-back path RP, the moving camera 356 moves from above the good die (corresponding to an example of the "first good die" of the present invention) at the position indicated by the star at timing T21 in FIG. 4 to above the good die H (corresponding to an example of the "second good die" of the present invention) according to the reference sequence RO (timing T21-T22). After that, die pickup (=(1) movement + (2) recognition + (3) suction) is performed in the order of the good dies H, I, J, K, L, and M.

[0046] Here, if the distance of the moving camera 356 in the first half P1 of the turn-back path RP exceeds the allowable movement amount (symbol MMP in FIG. 9), a map deviation occurs in the non-defective die H, as shown in the lower part of FIG. 4. In this specification, the mirror die MD is continuous to such an extent that the moving distance of the moving camera 356 along the first half P1 of the turn-back path RP exceeds the allowable movement amount. In addition, if this first half continuous condition is satisfied, as shown in FIG. 7A and FIG. 7B, it is possible to suppress the moving distance of the moving camera 356 to the allowable movement amount or less by changing at least a part of the order of the movement of the moving camera 356, the recognition of the produced die, and the suction. This point will be described later with reference to FIG. 7A and FIG. 7B.

[0047] <<Third occurrence pattern>> The third occurrence pattern occurs in the center of the wafer W, as shown in Fig. 5. In this occurrence pattern, a mirror die area MR is provided in the center of the wafer W, in which a plurality of mirror dies MD are formed in succession. For this reason, the moving camera 356 moves from above the good die (corresponding to an example of the "first good die" of the present invention) at the position indicated by the star at timing T31 in Fig. 5 to above the good die N (corresponding to an example of the "second good die" of the present invention) along the central path P3 corresponding to the reference order RO (timing T31-T32). After that, die pickup (=(1) movement + (2) recognition + (3) suction) is performed on the good die N (timing T32).

[0048] Here, if the distance of the moving camera 356 on the central path P3 exceeds the allowable movement amount (symbol MMP in FIG. 9), a map deviation occurs in the non-defective die N, as shown in the lower part of FIG. 5. In this specification, the condition that the mirror dies MD are continuous to such an extent that the moving distance of the moving camera 356 along the central path P3 exceeds the allowable movement amount is referred to as the central continuous condition. If this central continuous condition is satisfied, as shown in FIG. 8A and FIG. 8B, it is possible to suppress the moving distance of the moving camera 356 to the allowable movement amount or less by changing at least a part of the order of the movement of the moving camera 356, the recognition of the production die, and the suction from the reference order RO. This point will be described later with reference to FIG. 8A and FIG. 8B.

[0049] <How to fix map misalignment> <<How to resolve the first occurrence pattern>> 6A and 6B are diagrams showing a map deviation elimination method in the first occurrence pattern. The presence or absence of the first occurrence pattern can be determined based on the latter-half successive condition when the non-defective die currently being picked up is adjacent to the mirror die region MR, as shown in the schematic diagram at timing T11 in FIG. 6A, for example. If the latter-half successive condition is satisfied, in this embodiment, the calculation unit 110 changes the order of the movement of the moving camera 356 in the return path RP, the recognition of the produced die, and the suction from the reference order RO based on the pickup program. For example, when the allowable movement amount for the first occurrence pattern (symbol MMP in FIG. 9) is set to 4 pitches and 1 pitch in the X direction and Y direction, respectively, the die pickup may be configured to proceed in the following order. Here, "pitch" refers to the X-direction pitch of the die in the X direction and the Y-direction pitch of the die in the Y direction, and in this embodiment, the X-component distance and the Y-component distance of the allowable movement amount are shown as integer multiples of the X-direction pitch and the Y-direction pitch, respectively. However, the allowable movement amount is not limited to this, and may be specified by the actual dimensions.

[0050] Movement and recognition of the moving camera 356 (timing T14 in FIG. 6A)…As shown by the thick arrow in the figure, the moving camera 356 moves in the (-X) direction along the first half P1 of the return path RP by the X component distance (4 pitches) of the allowable movement amount, and then recognition of the non-defective die C is performed. Note that, at this stage, the non-defective die C is not picked up.

[0051] Movement, recognition, and pickup of the moving camera 356 (timing T15 in FIG. 6A)...As shown by the thick arrow in the figure, the moving camera 356 moves in the (-X) direction by two pitches in the X direction along the first half P1 of the turn-back path RP, and then recognition and pickup of the non-defective die A are performed. Note that in this embodiment, a four-pitch movement and a two-pitch movement are combined along the first half P1 of the turn-back path RP, but the combination is arbitrary as long as it is within the X component distance, and may be a combination of a two-pitch movement and a four-pitch movement, or a combination of a three-pitch movement and a three-pitch movement.

[0052] Die pickup on the reverse path (-P1) of the first half P1 of the turn-back path RP (timings T16 to T17 in FIG. 6B)...As shown by the thick arrow in the top row of the figure, the moving camera 356 moves one pitch along the path (-P) in the (+X) direction, and the pickup of the non-defective die is turned back. After this, the recognition and suction of the non-defective die B are performed. After that, similar to the non-defective die B, the non-defective dies C, D, E, and F are picked up in this order.

[0053] Movement of the moving camera 356 (timing T18 in FIG. 6B)... As shown by the thick arrow in the figure, the moving camera 356 moves by one pitch in each of the (+X) and (-Y) directions. As a result, the moving camera 356 is positioned above the next non-defective die G. This causes the moving camera 356 to return to the path according to the reference sequence RO.

[0054] After the non-defective dies G are recognized and picked up, the die pick-up is performed successively according to the reference sequence RO.

[0055] As described above, when performing die pickup of non-defective dies A to G present on the return path RP, the movement amount of the moving camera 356 is suppressed to the allowable movement amount for the first occurrence pattern or less. As a result, the map deviation in the first occurrence pattern can be eliminated.

[0056] In the method for eliminating the first occurrence pattern, the good dies A to G correspond to an example of the "die to be changed" of the present invention, and in particular, the good die A corresponds to the "die to be changed that is closest to the turning point" of the present invention. The process performed at timing T14 corresponds to an example of the process (c-1-1) of the present invention, the process performed at timing T15 corresponds to an example of the process (c-1-2) of the present invention, and the process performed at timings T16 to T17 corresponds to an example of the process (c-1-3) of the present invention. The process performed at timings T14 to T18 corresponds to an example of the processes (c-1) and (c) of the present invention.

[0057] <<How to resolve the second occurrence pattern>> 7A and 7B are diagrams showing a map deviation elimination method in the second occurrence pattern. The presence or absence of the second occurrence pattern can be determined based on the first half continuous condition when the non-defective die currently being picked up is adjacent to the mirror die area MR, as shown in the schematic diagram at timing T21 in FIG. 7A. Here, if the first half continuous condition is satisfied, in this embodiment, the calculation unit 110 changes the order of movement of the moving camera 356 on the return path RP, recognition of the produced die, and suction from the reference order RO based on the pickup program. For example, if the allowable movement amount (symbol MMP in FIG. 9) for the second occurrence pattern is set to 3 pitches and 1 pitch in the X direction and Y direction, respectively, the die pickup may be configured to proceed in the following order.

[0058] Movement and recognition of the moving camera 356 (timing T23 in FIG. 7A)...As shown by the thick arrow in the figure, the moving camera 356 moves in the (-X) direction by the X component distance (3 pitches) of the allowable movement amount, and moves in the (-Y) direction by the Y component distance (1 pitch) of the allowable movement amount. As a result, the moving camera 356 is positioned above the non-defective die J. After that, recognition of the non-defective die J is performed. Note that, at this stage, suction of the non-defective die J is not performed.

[0059] Movement, recognition, and adsorption of the moving camera 356 (timing T24 in FIG. 7A)...As shown by the thick arrow in the figure, the moving camera 356 moves in the (-X) direction by two pitches in the X direction, and is positioned above the non-defective die H. In this way, the moving camera 356 is returned to the path according to the reference sequence RO. Note that in this embodiment, the amount of movement in the X direction in the first half P1 of the turn-back path RP is a combination of three-pitch movement and two-pitch movement, but this is not limited to this, and the combination can be any combination within the X component distance of the allowable amount of movement, and may be a combination of two-pitch movement and three-pitch movement.

[0060] Die pickup according to the reference order RO (timing T24 in FIG. 7A, timings T25 to T26 in FIG. 7B)... As with the conventional device, die pickup is performed in the order of non-defective dies H, I, J, K, L, and M. After that, die pickup is performed continuously according to the reference order RO.

[0061] As described above, when performing die pickup of the non-defective dies H to M present on the return path RP, the movement amount of the moving camera 356 is suppressed to the allowable movement amount for the second occurrence pattern or less. As a result, the map deviation in the second occurrence pattern can be eliminated.

[0062] In the method for eliminating the second occurrence pattern, the good dies H to M correspond to an example of the "die to be changed" of the present invention, and in particular, the good die H corresponds to the "die to be changed that is closest to the turning point" of the present invention. The process performed at the timings T23 to T24 corresponds to an example of the process (c-2-1) of the present invention, the process performed at the timings T24 corresponds to an example of the process (c-2-2) of the present invention, and the process performed at the timings T25 to T26 corresponds to an example of the process (c-2-3) of the present invention. The process performed at the timings T23 to T26 corresponds to an example of the processes (c-2) and (c) of the present invention.

[0063] <<How to resolve the third occurrence pattern>> 8A and 8B are diagrams showing a map deviation elimination method in the third occurrence pattern. The presence or absence of the third occurrence pattern can be determined based on the central continuity condition when the currently picked-up target good die (corresponding to an example of the "first good die" of the present invention) is adjacent to the mirror die area MR, for example, as shown in the schematic diagram at timing T31 in FIG. 8A. Here, if the central continuity condition is satisfied, in this embodiment, the calculation unit 110 moves the moving camera 356 along a detour path from the first good die (the position of the star in the schematic diagram) through the periphery of the mirror die area MR to the next good die N (corresponding to an example of the "second good die" of the present invention) based on the pickup program, and recognizes the production die. That is, the calculation unit 110 changes the movement of the moving camera 356 and the order of the production die from the reference order RO. For example, when the allowable movement amount (symbol MMP in FIG. 9) for the third occurrence pattern is set to 3 pitches and 2 pitches in the X direction and Y direction, respectively, the die pickup may be configured to proceed in the following order.

[0064] Movement and recognition of the moving camera 356 (timing T33 in FIG. 8A)...As shown by the thick arrow in the figure, the moving camera 356 moves in the (+X) direction by one pitch, which is less than the X component distance of the allowable movement amount, and moves in the (-Y) direction by the Y component distance (two pitches) of the allowable movement amount. As a result, the moving camera 356 is positioned above the non-defective die O. After that, recognition of the non-defective die O is performed. Note that, at this stage, suction of the non-defective die O is not performed.

[0065] Movement and recognition of the moving camera 356 (timing T34 in FIG. 8A)...As shown by the thick arrow in the figure, the moving camera 356 moves in the (+X) direction by the X component distance (3 pitches) of the allowable movement amount, and moves in the (-Y) direction by the Y component distance (2 pitches) of the allowable movement amount. As a result, the moving camera 356 is positioned above the non-defective die P. After that, recognition of the non-defective die P is performed. Note that, at this stage, the non-defective die P is not picked up.

[0066] Movement and recognition of the moving camera 356 (timing T35 in FIG. 8B)...As shown by the thick arrow in the figure, the moving camera 356 moves in the (+X) direction by two pitches, which is less than the X component distance of the allowable movement amount, and moves in the (+Y) direction by the Y component distance (two pitches) of the allowable movement amount. As a result, the moving camera 356 is positioned above the non-defective die Q. After that, recognition of the non-defective die Q is performed. Note that, at this stage, suction of the non-defective die Q is not performed.

[0067] Movement, recognition, and suction of the moving camera 356 (timing T36 in FIG. 8B)...As shown by the thick arrow in the figure, the moving camera 356 moves in the (-X) direction by one pitch less than the X component distance of the allowable movement amount, and moves in the (+Y) direction by the Y component distance (2 pitches) of the allowable movement amount. As a result, the moving camera 356 is positioned above the non-defective die N. In this way, the moving camera 356 is returned to the path according to the reference sequence RO. After this, recognition and suction of the non-defective die N are performed. Note that in this embodiment, in order to make the shortest detour around the mirror die area MR while keeping the movement distance of the moving camera 356 within the allowable movement amount, the detour path shown by the thick arrow in FIG. 8A and FIG. 8B is selected, but the detour path can be appropriately changed according to the shape and size of the mirror die area MR.

[0068] Die pickup according to the reference order RO: After being returned to the reference order RO, die pickup according to the reference order RO is continuously performed.

[0069] As described above, when the central path P3 exists, the moving camera 356 is moved and recognized repeatedly within the allowable movement amount, so that the camera is moved to the next non-defective die N by making the shortest detour around the mirror die region MR. As a result, the map deviation in the third occurrence pattern can be eliminated.

[0070] In the method for eliminating the third occurrence pattern, the steps performed at timings T33 to T36 correspond to an example of steps (c-3) and (c) of the present invention.

[0071] <Pickup operation> FIG. 9 is a flowchart showing the pickup operation of a non-defective die in the mounter shown in FIG. 1. The pickup operation is performed by the calculation unit 110 controlling each unit of the device based on the pickup program as follows. The calculation unit 110 determines whether or not an allowable movement amount (MMP) corresponding to the wafer W to be picked up has already been set and stored in the storage unit 140 in step S1. If the allowable movement amount has not been set, the calculation unit 110 proceeds to step S4 after executing a setting process of the allowable movement amount (steps S2 and S3). In step S2, the calculation unit 110 displays a message on the display unit 180 to prompt the user to set the allowable movement amount, as shown in FIG. 9, for example. Then, the calculation unit 110 stores the allowable movement amount set by the user in the storage unit 140 (step S3). Note that the allowable movement amount may be set to a different value for each occurrence pattern as described above, or may be set to the same value partially or entirely. Furthermore, the relationship between the type of wafer W and the allowable movement amount may be stored in advance in the storage unit 140, and the allowable movement amount may be automatically set according to the type of wafer W instead of being set by the user.

[0072] On the other hand, if the allowable movement amount has already been set, the calculation unit 110 proceeds directly to step S4.

[0073] In steps S4 to S6, the calculation unit 110 performs a movement distance determination when the non-defective die currently being picked up is adjacent to the mirror die region MR. This movement distance determination is to determine whether or not the movement distance exceeds the allowable movement amount (MMP) required to keep the map deviation amount after the movement within the allowable value, for each movement of the moving camera 356 that passes above the mirror die region MR among the movements of the moving camera 356 according to the reference sequence RO. In other words, the calculation unit 110 functions as the "movement distance determination unit" of the present invention. For example, when the latter half continuous condition is satisfied (see the top of FIG. 3 and FIG. 6A), the calculation unit 110 determines that the first occurrence pattern is applicable ("YES" in step S4). Then, the calculation unit 110 controls each unit of the device so that the die pickup operation is performed according to the procedure described in the above section "Method of eliminating the first occurrence pattern" (step S7). That is, the calculation unit 110 changes the order of at least a part of the movement of the moving camera 356, the recognition of the produced die, and the pickup from the reference order RO, thereby suppressing the above-mentioned movement distance to within the allowable movement amount. In this way, the calculation unit 110 functions as the "order change unit" of the present invention. This also applies to steps S8 and S9 described below.

[0074] Furthermore, if the first half continuous condition is satisfied (see the top rows of FIG. 4 and FIG. 7A), the calculation unit 110 determines that the second occurrence pattern applies ("YES" in step S5). Then, the calculation unit 110 controls each part of the device so that the die pickup operation is performed according to the procedure described in the above section "Method for eliminating the second occurrence pattern" (step S8).

[0075] Furthermore, if the central continuity condition is satisfied (see the top rows of FIG. 5 and FIG. 8A), the calculation unit 110 determines that the third occurrence pattern applies (YES in step S6). Then, the calculation unit 110 controls each part of the device so that the die pickup operation is performed according to the procedure described in the above section "Method of eliminating the third occurrence pattern" (step S9).

[0076] On the other hand, if the good die currently being picked up is not adjacent to the mirror die area MR, or if the adjacent die is not in a situation where map misalignment would occur ("NO" in all of steps S4 to S6), the calculation unit 110 controls each part of the device so that die pickup is performed in the standard order RO (step S10).

[0077] In the next step S11, the calculation unit 110 determines whether or not any good dies remain on the wafer W. If any good dies remain, the calculation unit 110 returns to step S4 and continues the die pick-up. On the other hand, when picking up all good dies is completed, the calculation unit 110 ends the series of processes.

[0078] As described above, in this embodiment, for any of the first to third occurrence patterns, the movement of the moving camera 356 and the recognition and pickup of the produced dies are partly changed from the reference sequence RO, so that the movement distance of the moving camera 356 is kept within the permissible movement amount (MMP). Therefore, map deviation is suppressed, and non-defective dies can be accurately picked up from the wafer W including the mirror dies MD.

[0079] Furthermore, at timings T14, T23, and T34, the moving camera 356 is moved and the produced dies are recognized at the permissible movement amount (MMP). Therefore, the number of times the moving camera 356 is moved and the produced dies are recognized without picking up the non-defective dies is reduced. As a result, the time required for die pickup can be shortened.

[0080] In the above embodiment, the moving camera 356 and the take-out head 36 correspond to an example of the "imaging unit" and the "head" of the present invention, respectively. Also, the X-axis motors 352 and 357 for moving the moving camera 356 and the take-out head 36 in the X direction and the Y-axis motor 355 for moving them in the Y direction correspond to an example of the "moving unit" of the present invention.

[0081] 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, in the above embodiment, the present invention is applied to an apparatus that picks up a non-defective die from a wafer W having mirror dies MD provided at the periphery and center, but the present invention can also be applied to a wafer W having mirror dies MD provided only at the periphery or only at the center. [Industrial Applicability]

[0082] The present invention can be applied to all die pick-up techniques for picking up non-defective dies from a diced wafer. [Explanation of symbols]

[0083] 36…Removal head 100...Control unit 160…Wafer map 352, 357…X-axis motor (moving part) 355…Y-axis motor (moving part) 356...Mobile camera (imaging unit) A~Q: Good die MD...Mirror die MR: Mirror die area P1: First half (of the return route) P2: (Later part of the return route) P3: Central route RO…Reference order RP: Return route W…wafer Wp: Parts (good dies)

Claims

1. A die pick-up method for a wafer having production dies on which patterns are formed and mirror dies on which patterns are not formed, the method comprising the steps of: referring to a wafer map that is created in advance to indicate the quality of each of the production dies; and for each good die among the production dies, moving an imaging unit that images the production die, recognizing the production die, and adsorbing the good die by a head based on a result of the recognition, thereby picking up the good die in sequence. (a) storing an order of movement of the imaging unit according to the wafer map, recognition of the produced dies, and pickup as a reference order; (b) determining whether or not a movement distance of the imaging unit exceeds an allowable movement amount required for keeping a map deviation amount after the movement within an allowable value, for each movement of the imaging unit that passes above the mirror die in the movement of the imaging unit according to the reference sequence; (c) when it is determined in the step (b) that the moving distance exceeds the allowable moving amount, changing an order of at least a part of the moving of the imaging unit, the recognition of the produced die, and the chucking from the standard order, thereby suppressing the moving distance to be equal to or less than the allowable moving amount; Equipped with a mirror die area in which a plurality of the mirror dies are formed continuously along a central path along which the imaging unit moves along the central portion of the wafer in accordance with the reference sequence; a moving distance of the imaging unit in the step (b) is a distance between a first conforming die that is picked up immediately before the imaging unit moves to the mirror die area in accordance with the reference sequence and a second conforming die that is picked up immediately after the imaging unit passes through the mirror die area; The step (c) changing the reference order by changing an order of movement of the imaging unit and the recognition such that the imaging unit moves along a detour path from the first conforming die to the second conforming die via a periphery of the mirror die area; A die pickup method comprising the steps of:

2. 2. The die pickup method according to claim 1, The step of changing the order in step (c) includes a step of moving the imaging unit by the permissible movement amount and performing the recognition at least once.

3. 1. A die pickup device for picking up a non-defective die from a wafer having a production die on which a pattern is formed and a mirror die on which no pattern is formed, the die pickup device comprising: An imaging unit that images the production die; A head for suctioning the non-defective die; a moving unit that moves the imaging unit and the head above the wafer; a storage unit that stores, as a reference order, an order of movement of the imaging unit, recognition of the produced dies, and the chucking in accordance with a wafer map that is created in advance as an indication of the quality of each of the produced dies; a control unit that controls the head and the imaging unit, The control unit: a movement distance determination unit that determines whether or not a movement distance of the imaging unit exceeds an allowable movement amount required to keep a map deviation amount after the movement within an allowable value, for each movement of the imaging unit that passes above the mirror die among the movements of the imaging unit according to the reference sequence; and an order change unit that, when it is determined that the movement distance exceeds the allowable movement amount, changes an order of at least a part of the movement of the imaging unit, the recognition of the production die, and the pickup from the reference order to suppress the movement distance to be equal to or less than the allowable movement amount, a mirror die area in which a plurality of the mirror dies are formed continuously along a central path along which the imaging unit moves along the central portion of the wafer in accordance with the reference sequence; the movement distance determination unit determines a distance between a first conforming die that is picked up just before the imaging unit moves to the mirror die area in accordance with the reference sequence and a second conforming die that is picked up just after the imaging unit passes through the mirror die area as the movement distance, and determines whether the movement distance exceeds the allowable movement amount; The order change unit changes the order of the movement of the imaging unit and the recognition so that the imaging unit moves along a detour path from the first good die to the second good die via a periphery of the mirror die area, as the change of the reference order. A die pickup device comprising:

Images