JP7550558B2 - Pick-up method and pickup device - Google Patents

Description

The present invention relates to a pickup method and pickup device for picking up chips from a wafer unit in which a wafer divided into multiple chips is fixed to an annular frame via tape.

A pickup device is used to peel off the chips of a wafer, which is divided into multiple chips and attached to a tape with the outer periphery of the tape attached to an annular frame to form a wafer unit (see, for example, Patent Document 1).

When picking up chips from a wafer unit, the pickup device shown in the aforementioned Patent Document 1 expands the tape to form a desired gap between adjacent chips in order to prevent the chip being picked up from coming into contact with and being damaged by the adjacent chips, and picks up the chips in that state. The pickup device shown in the aforementioned Patent Document 1 expands the tape a predetermined amount in order to form the desired gap between the chips.

JP 2008-177260 A

The amount of tape expansion varies depending on the type of wafer or tape, so the pickup device shown in the aforementioned Patent Document 1 finds the optimal amount of expansion for each type and sets the expansion conditions. However, finding the optimal expansion conditions every time the wafer unit is changed is a time-consuming task, and improvements were desperately needed.

The present invention was made in consideration of these problems, and its purpose is to provide a pickup method and pickup device that can pick up chips without damaging them while minimizing the effort required.

In order to solve the above-mentioned problems and achieve the object, the pick-up method of the present invention is a pick-up method for picking up chips from a wafer unit in which a wafer divided into multiple chips is fixed to an annular frame via tape, and is characterized by comprising a fixing step of fixing the annular frame of the wafer unit, an expanding step of expanding the tape to form a gap between adjacent chips and detecting the gap while imaging the wafer of the wafer unit including the annular frame fixed in the fixing step, and a pick-up step of stopping the expansion of the tape when a predetermined gap is formed between adjacent chips, and picking up the chips from the tape to which the chips having the predetermined gap formed between adjacent chips of the wafer unit are affixed.
In the above-mentioned pick-up method, in the pick-up step, after forming a predetermined interval between adjacent chips and stopping the expansion of the tape, the tape around the chip to be picked up is sucked and held on the upper surface of the outer layer of a push-up means for pushing up the chip, the chip is supported via the tape by a columnar first push-up pin of the push-up means and a second push-up pin which is formed in a cylindrical shape surrounding the first push-up pin and is surrounded by the outer layer, and the chip is supported by a lower surface of a pickup collet which faces the push-up means with the chip sandwiched therebetween. the chip is brought into contact with the chip, the chip is clamped between the pickup collet and the push-up means, the first push-up pin and the second push-up pin are caused to push up the clamped chip, the outer layer portion and the second push-up pin are moved away from the chip, and the chip is clamped between the first push-up pin and the pickup collet, whereby the tape is peeled off from the outer peripheral edge of the chip, the chip is suction-held on the underside of the pickup collet, and the chip suction-held by the pickup collet is then picked up from the tape.

In the pickup method, the expansion step may detect the gap at the center of the wafer.

The pick-up method may further include a detection step of imaging the wafer and detecting the coordinate position of the chip to be picked up after performing the expansion step and before performing the pick-up step.

The pickup device of the present invention is a pickup device for picking up chips from a wafer unit in which a wafer divided into a plurality of chips is fixed to an annular frame via a tape, and includes a fixing unit for fixing the annular frame of the wafer unit, an imaging camera for imaging the wafer of the wafer unit including the annular frame fixed by the fixing unit, an expansion means for pressing and expanding the tape between the inner peripheral edge of the annular frame fixed by the fixing unit and the outer peripheral edge of the wafer to form a gap between adjacent chips, a push-up means for pushing up the chips through the tape expanded by the expansion means, and a push-up means for pushing up the chips through the tape expanded by the expansion means. and a pickup collet which picks up the chips lifted up, and a controller which controls at least the imaging camera, the expanding means, the push-up means, and the pickup collet, wherein the controller detects the gap between adjacent chips based on an image captured by the imaging camera, and when a predetermined gap is formed between adjacent chips, controls the controller to stop expanding the tape by the expanding means, push up the chips attached to the tape with a predetermined gap formed between the adjacent chips by the push-up means, and pick up the chips pushed up by the push-up means with the pickup collet.
In the pickup device, the controller may, after forming a predetermined gap between adjacent chips and stopping the expansion of the tape, suction-hold the tape around the chip to be picked up on an upper surface of the outer layer of the push-up means, support the chip via the tape with a columnar first push-up pin of the push-up means and a second push-up pin that is formed in a cylindrical shape surrounding the first push-up pin and is surrounded by the outer layer, bring the lower surface of the pickup collet into contact with the chip to sandwich the chip between the pickup collet and the push-up means, cause the first push-up pin and the second push-up pin to push up the sandwiched chip, move the outer layer and the second push-up pin away from the chip, and hold the chip between the first push-up pin and the pickup collet, thereby peeling the tape from the outer peripheral edge of the chip, and hold the chip on the lower surface of the pickup collet by suction, and then pick up the chip that is suction-held by the pickup collet from the tape.

In the pickup device, the controller may position the imaging camera at the center of the wafer and detect the distance based on the captured image.

In the pickup device, the controller may position the imaging camera at a position corresponding to the chip to be picked up and detect the coordinates of the chip to be picked up based on the captured image.

The present invention has the advantage that it can pick up chips without damaging them while minimizing the effort required.

FIG. 1 is a perspective view showing a main part of a configuration example of a pickup device according to a first embodiment. FIG. 2 is a cross-sectional view of a wafer unit including chips to be picked up by the pick-up device shown in FIG. FIG. 3 is a side view showing, in cross section, a part of a main portion of the pickup device shown in FIG. FIG. 4 is a flowchart showing the flow of the pick-up method according to the first embodiment. FIG. 5 is a side view, partly in section, showing the fixing step of the pick-up method shown in FIG. FIG. 6 is a side view, partly in section, showing an extended step of the pick-up method shown in FIG. FIG. 7 is a diagram showing an example of a captured image acquired by the imaging unit in the extended step of the pickup method shown in FIG. FIG. 8 is a diagram showing another example of a captured image acquired by the imaging unit in the extended step of the pickup method shown in FIG. FIG. 9 is a side view, partly in section, illustrating the detection step of the pick-up method shown in FIG. FIG. 10 is a diagram showing an example of a captured image acquired by the imaging unit in the detection step of the pick-up method shown in FIG. FIG. 11 is a cross-sectional view that typically shows a state in which a chip to be picked up is clamped between a push-up unit and a pickup collet in the pick-up step of the pick-up method shown in FIG. FIG. 12 is a cross-sectional view showing a state where the push-up unit starts to push up the chip through the tape in the pick-up step of the pick-up method shown in FIG. FIG. 13 is a cross-sectional view that typically shows a state in which the chip pushed up via the tape by the push-up unit is sucked and held by the pickup collet in the pick-up step of the pick-up method shown in FIG.

The following describes in detail the form (embodiment) for carrying out the present invention with reference to the drawings. The present invention is not limited to the contents described in the following embodiment. The components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Various omissions, substitutions, or modifications of the configuration can be made without departing from the spirit of the present invention.

[Embodiment 1]
A pickup device according to a first embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing a main part of a configuration example of the pickup device according to the first embodiment. Fig. 2 is a cross-sectional view of a wafer unit including chips to be picked up by the pickup device shown in Fig. 1. Fig. 3 is a side view showing a cross-section of a part of the main part of the pickup device shown in Fig. 1.

The pickup device 1 shown in FIG. 1 according to the first embodiment is a device that picks up a chip 14 from a wafer unit 17 shown in FIG. 2.

(Wafer unit)
2, in the wafer unit 17, a wafer 10 divided into a plurality of chips 14 is fixed to an annular frame 16 via tape 15. The wafer 10 is a disk-shaped semiconductor wafer, an optical device wafer, or the like, with a substrate 11 made of silicon, sapphire, gallium, or the like.

The wafer 10 has devices 13 formed in areas partitioned by a plurality of planned division lines 12 formed in a grid pattern on the surface 11-1 of the substrate 11. In the first embodiment, the wafer 10 has a disk-shaped tape 15, which is larger in diameter than the wafer 10, attached to the underside 11-2, and an annular frame 16 attached to the outer edge of the tape 15, forming a wafer unit 17. The wafer 10 is also cut along the planned division lines 12 to be divided into individual chips 14. That is, the wafer 10 has cutting grooves 18 formed between the chips 14, which penetrate the wafer 10 itself. The chips 14 include a part of the substrate 11 and the devices 13.

(Pickup device)
The pickup device 1 is a device that picks up the chips 14 from the tape 15 of the above-mentioned wafer unit 17. As shown in Fig. 1, the pickup device 1 includes a fixed unit 20, a moving mechanism 30 that moves the fixed unit 20, an imaging camera 40, a light source unit 50, an expansion unit 60 (shown in Fig. 3) that is an expansion means, a push-up unit 70 that is a push-up means, a pickup mechanism 80, a collet moving mechanism 90, and a control unit 100 that is a controller.

(Fixed unit)
The fixing unit 20 fixes the annular frame 16 of the wafer unit 17. As shown in Fig. 1, the fixing unit 20 is installed on a moving table 21 installed on the apparatus main body 2. As shown in Fig. 3, the fixing unit 20 includes a support table 22 installed on the moving table 21, a support frame 23 installed on the support table 22, an annular frame support member 24 installed on the support frame 23, an annular frame pressing member 25 installed above the frame support member 24 and fixed to the support frame 23, and a lifting cylinder 26 that lifts and lowers the frame support member 24 along the Z-axis direction parallel to the vertical direction.

The frame support member 24 and the frame holding member 25 are formed in ring shapes with equal inner and outer diameters, are positioned coaxially, and are stacked at a distance in the Z-axis direction. In the first embodiment, the lifting cylinder 26 comprises a cylinder 261 fixed to the support frame 23, and a rod 262 provided so as to be able to extend and retract from the cylinder 261. The frame support member 24 is fixed to the tip of the rod 262, and when it extends from the cylinder 261, it raises the frame support member 24 along the Z-axis direction, and when it retracts to the cylinder 261, it lowers the frame support member 24 along the Z-axis direction.

In the fixing unit 20, the annular frame 16 of the wafer unit 17 is placed on the lowered frame support member 24 by a transport unit (not shown). When the annular frame 16 of the wafer unit 17 is placed on the upper surface of the frame support member 24, the lifting cylinder 26 raises the frame support member 24, sandwiching the annular frame 16 between the frame holding member 25 and the frame support member 24 to fix the wafer unit 17.

(Moving mechanism)
The moving mechanism 30 includes an X-axis moving mechanism 31 that is provided on the apparatus body 2 and moves the moving table 21, i.e., the fixed unit 20, in the X-axis direction parallel to the horizontal direction, and a Y-axis moving mechanism 32 that is provided on the moving table 21 moved in the X-axis direction by the X-axis moving mechanism 31 and moves the support table 22, i.e., the fixed unit 20, in the Y-axis direction parallel to the horizontal direction and perpendicular to the X-axis direction. Each of the moving mechanisms 31, 32 includes well-known ball screws 33, 34 that are provided rotatably about their axes, well-known motors 35, 36 that rotate the ball screws 33, 34 about their axes, and well-known guide rails 37, 38 that support the moving table 21 or the support table 22 movably in the X-axis or Y-axis direction.

(Imaging camera)
The imaging camera 40 images the wafer 10 of the wafer unit 17 including the annular frame 16 fixed by the fixing unit 20. In the first embodiment, the imaging camera 40 is disposed above the center of the recess 3 provided at one end of the device body 2 in the X-axis direction. In the first embodiment, the imaging camera 40 is disposed above the center, which is the central portion of the wafer 10 of the wafer unit including the annular frame 16 fixed by the fixing unit 20 disposed above the recess 3 by the moving mechanism 30, and images the center of the wafer 10 of the wafer unit 17. The imaging camera 40 images the chip 14 at the center of the wafer 10 of the wafer unit 17 and the surroundings of this chip 14 to form captured images 201, 202 (shown in FIGS. 7 and 8).

The imaging camera 40 is also positioned above the push-up unit 70 by the moving mechanism 30, and captures the chip 14 to be picked up from the tape 15 and the surroundings of the chip 14 to form an image 203 (shown in FIG. 10).

The imaging camera 40 has an imaging element (i.e., a pixel) that images the chip 14 of the wafer 10 of the wafer unit 17 including the annular frame 16 held by the fixing unit 20 and the surroundings of the chip 14. The imaging element is, for example, a CCD (Charge-Coupled Device) imaging element or a CMOS (Complementary MOS) imaging element. The imaging camera 40 captures the chip 14 of the wafer 10 of the wafer unit 17 including the annular frame 16 held by the fixing unit 20 and the surroundings of the chip 14, obtains the captured images 201, 202, and 203, and outputs the obtained captured images 201, 202, and 203 to the control unit 100.

(Light source unit)
The light source unit 50 is provided in the recess 3 of the device main body 2, and irradiates illumination light onto the wafer 10 through the tape 15 of the wafer unit 17, which includes an annular frame 16 fixed by a fixed unit 20 positioned above the recess 3 by a moving mechanism 30.

(Expansion unit)
The expansion unit 60 is a unit that presses and expands the tape 15 between the inner peripheral edge of the annular frame 16 fixed by the fixing unit 20 and the outer peripheral edge of the wafer 10, thereby forming a gap 19 (shown in FIG. 11 ) between adjacent chips 14.

In the first embodiment, the expansion unit 60 includes an expansion cylinder 61 and a cylindrical expansion drum 62, as shown in FIG. 3. The expansion cylinder 61 raises and lowers the support frame 23, i.e., the frame support member 24 and the frame holding member 25 of the fixed unit 20, along the Z-axis direction.

The expansion cylinder 61 comprises a cylinder 611 fixed to the support table 22 and a rod 612 provided so as to be freely extendable from the cylinder 611. The support frame 23 is fixed to the tip of the rod 612, and when it extends from the cylinder 611, it raises the support frame 23, i.e., the frame support member 24 and the frame holding member 25, along the Z-axis direction, and when it retracts to the cylinder 611, it lowers the support frame 23, i.e., the frame support member 24 and the frame holding member 25, along the Z-axis direction. The expansion cylinder 61 raises and lowers the frame support member 24 and the frame holding member 25 along the Z-axis direction, thereby raising and lowering the wafer unit 17 including the annular frame 16 fixed by the frame support member 24 and the frame holding member 25 along the Z-axis direction.

The expansion drum 62 is formed in a cylindrical shape with an inner diameter larger than the outer diameter of the wafer 10 and smaller than the inner diameter of the annular frame 16, and is arranged in a position that is approximately coaxial with the wafer 10 and the annular frame 16 of the wafer unit 17 fixed by the fixing unit 20 on the support table 22. The upper end of the expansion drum 62 is arranged below the upper surface of the frame support member 24 lowered by the lifting cylinder 26 and raised by the expansion cylinder 61. The upper end of the expansion drum 62 is arranged above the upper surface of the frame support member 24 raised by the lifting cylinder 26 and lowered by the expansion cylinder 61.

In the expansion unit 60, when the lifting cylinder 26 raises the frame support member 24 and the fixed unit 20 fixes the wafer unit 17, the rod 612 of the expansion cylinder 61 contracts and lowers the fixed unit 20, thereby pressing the tape 15 between the inner edge of the annular frame 16 and the outer edge of the wafer 10 with the upper end of the expansion drum 62, thereby expanding the tape 15.

(Thrust-up unit)
The push-up unit 70 pushes up the chip 14 through the tape 15 expanded by the adjustment unit. The push-up unit 70 is provided next to the light source unit 50 in the recess 3 of the device body 2, and is disposed in a position facing the imaging camera 40 along the Z-axis direction, i.e., below the imaging camera 40.

The push-up unit 70 is connected as a whole to a lifting mechanism (not shown) composed of a motor or the like, and moves up and down along the Z-axis direction. As shown in FIG. 3, the push-up unit 70 includes an outer layer portion 71 formed in a hollow cylindrical shape, and a quadrangular prism-shaped push-up portion 72 disposed inside the outer layer portion 71. A plurality of suction grooves 74 are formed in the upper surface 78 of the outer layer portion 71, and are formed in a concentric shape along the circumferential direction of the outer layer portion 71. Each of the suction grooves 74 is connected to a suction source 87 composed of an ejector or the like via a suction passage 75 and an opening/closing valve 76 formed inside the push-up unit 70.

The push-up section 72 includes a first push-up pin 72-1 formed in a square prism shape, a second push-up pin 72-2 formed in a square tube shape surrounding the first push-up pin 72-1, and a third push-up pin 72-3 formed in a square tube shape surrounding the second push-up pin 72-2. The first push-up pin 72-1, the second push-up pin 72-2, and the third push-up pin 72-3 are each push-up members that push up one of the chips 14 through the tape 15 of the wafer unit 17 including the annular frame 16 held by the fixed unit 20. The first push-up pin 72-1, the second push-up pin 72-2, and the third push-up pin 72-3 are each connected to a lifting mechanism (not shown) composed of a motor or the like, and move up and down along the Z-axis direction.

With the wafer unit 17 including the annular frame 16 held by the fixing unit 20 positioned above, the push-up unit 70 sucks the suction grooves 74 on the upper surface 78 of the outer layer 71 with the suction source 87, and holds the periphery of the chip 14 on the tape 15 on the upper surface 78 of the outer layer 71. The push-up unit 70 holds the periphery of the chip 14 on the tape 15 on the upper surface 78 of the outer layer 71 by suction, and the push-up pins 72-1, 72-2, 72-3 of the push-up unit 72 are raised, pushing up the chip 14 above the tape 15. The dimensions of the push-up unit 70 are adjusted appropriately according to the size of the chip 14.

In the first embodiment, when the push-up unit 70 pushes up the chip 14, the lifting mechanism starts to raise the first push-up pin 72-1, the second push-up pin 72-2, and the third push-up pin 72-3 at the same time and at the same speed, the second push-up pin 72-2 is raised above the third push-up pin 72-3, the first push-up pin 72-1 is raised above the second push-up pin 72-2, and the rise of each pin stops. That is, when the push-up unit 70 pushes up the chip 14, the first push-up pin 72-1, the second push-up pin 72-2, and the third push-up pin 72-3 start to rise at the same time and at the same speed, and the third push-up pin 72-3, the second push-up pin 72-2, and the first push-up pin 72-1 stop rising in order.

(Pickup mechanism)
The pickup mechanism 80 picks up the chips 14 pushed up by the push-up unit 70 from the wafer 10 which is divided into a plurality of chips 14 and supported by the tape 15. As shown in Fig. 1, the pickup mechanism 80 includes a moving base 82 which is moved in the Y-axis direction and the Z-axis direction by a collet moving mechanism 90, an arm 84 which extends in the X-axis direction from the moving base 82 in a direction away from the collet moving mechanism 90, and a pickup collet 86 which is provided at the tip of the arm 84 and holds the chips 14.

The pickup collet 86 faces the push-up pins 72-1, 72-2, and 72-3 of the push-up unit 70, sandwiching the wafer unit 17 held by the fixed unit 20 positioned above the recess 3 by the moving mechanism 30, and holds the chip 14 pushed up by the push-up pins 72-1, 72-2, and 72-3 of the push-up unit 70 to pick it up from the tape 15. The pickup collet 86 is attached to the lower end of the tip of the arm 84. As shown in FIG. 3, the pickup collet 86 has a suction groove 89 formed on its lower surface 88, which is connected to a suction source 87 such as an ejector via a suction path 83 and an on-off valve 85.

With the chip 14 pushed up by the push-up pins 72-1, 72-2, and 72-3 in contact with the underside 88 of the pickup collet 86, the suction groove 89 is sucked by the suction source 87, and the chip 14 is sucked and held on the underside 88. The pickup collet 86 sucks and holds the chip 14 pushed up by the push-up pins 72-1, 72-2, and 72-3 of the push-up unit 70 on the underside 88, and is raised by the collet movement mechanism 90 to pick up the chip 14 sucked and held on the underside 88 from the tape 15.

In addition, in the first embodiment, the pickup device 1 may be provided with a load cell, which is a measuring means for measuring the load applied to the chip 14 when it is picked up from the tape 15, on the upper surface side of the push-up unit 70. The load cell outputs the measurement result to the control unit 100. In the present invention, the load cell, which is a measuring means, may be provided on the lower surface 88 side of the pickup collet 86 of the pickup mechanism 80.

(Collet moving mechanism)
The collet moving mechanism 90 moves the pickup collet 86 in the Y-axis direction and also moves the pickup collet 86 in the Z-axis direction. The collet moving mechanism 90 includes a second Y-axis moving mechanism 91 that is provided on the apparatus main body 2 and moves a moving table 93 in the Y-axis direction, and a Z-axis moving mechanism 92 that is provided on the moving table 93 moved in the Y-axis direction by the second Y-axis moving mechanism 91 and moves the moving base 82, i.e., the pickup mechanism 80, in the Z-axis direction.

Each of the moving mechanisms 91, 92 includes a well-known ball screw 94, 95 that is rotatable around its axis, a well-known motor 96, 97 that rotates the ball screw 94, 95 around its axis, and a well-known guide rail 98, 99 that supports the moving table 93 or the pickup mechanism 80 so that it can move in the Y-axis or Z-axis direction.

As shown in FIG. 1, the pickup device 1 also includes an X-axis position detection unit 110 for detecting the X-axis position of each chip 14 of the wafer 10 of the wafer unit 17 fixed to the fixed unit 20, and a Y-axis position detection unit 120 for detecting the Y-axis position of each chip 14 of the wafer 10 of the wafer unit 17 fixed to the fixed unit 20.

The X-axis direction position detection unit 110 can be composed of a linear scale 111 parallel to the X-axis direction installed on the device body 2, and a read head (not shown) installed on the moving table 21 and moving in the X-axis direction together with the fixed unit 20. The X-axis direction position detection unit 110 detects the position of the moving table 21 in the X-axis direction relative to the device body 2, thereby detecting the X-axis direction position of each chip 14 within the imaging range of the imaging camera 40 among the wafers 10 of the wafer unit 17 fixed to the fixed unit 20.

The Y-axis position detection unit 120 can be composed of a linear scale 121 parallel to the Y-axis direction installed on the moving table 21, and a read head (not shown) installed on the support table 22 and moving in the Y-axis direction together with the fixed unit 20. The Y-axis position detection unit 120 detects the Y-axis position of each chip 14 within the imaging range of the imaging camera 40 of the wafer 10 of the wafer unit 17 fixed to the fixed unit 20 by detecting the Y-axis position of the support table 22 relative to the moving table 21. The X-axis position detection unit 110 and the Y-axis position detection unit 120 output the X-axis or Y-axis position of each chip 14 of the wafer 10 of the wafer unit 17 fixed to the fixed unit 20 to the control unit 100.

In the first embodiment, the position of each chip 14 of the wafer 10 of the wafer unit 17 fixed to the fixing unit 20 is determined by the distance in the X-axis direction and the distance in the Y-axis direction from a predetermined reference position.

(Control Unit)
The control unit 100 controls each of the above-mentioned constituent units of the pickup device 1, namely, the fixed unit 20, the imaging camera 40, the light source unit 50, the moving mechanism 30, the expansion unit 60, the push-up unit 70, the pickup mechanism 80 (i.e., the pickup collet 86, and the collet moving mechanism 90), and causes the pickup device 1 to perform a pickup operation for picking up the chip 14 from the wafer unit 17. That is, the control unit 100 controls at least the imaging camera 40, the expansion unit 60, the push-up unit 70, and the pickup collet 86.

The control unit 100 is a computer having an arithmetic processing device with a microprocessor such as a CPU (central processing unit), a storage device with memory such as a ROM (read only memory) or a RAM (random access memory), and an input/output interface device. The arithmetic processing device of the control unit 100 performs arithmetic processing according to a computer program stored in the storage device, and outputs control signals for controlling the pickup device 1 to each of the above-mentioned units of the pickup device 1 via the input/output interface device.

The control unit 100 is also connected to a display unit, which is a display means having a display screen that displays the status of the pickup operation, images, etc., and a touch panel, which is an input means used by an operator to input information, etc., to the control unit 100 of the pickup device 1. The display unit is composed of a liquid crystal display device or the like. The touch panel is overlaid on the display screen of the display unit.

The control unit 100 also includes a gap detection unit 101, a coordinate detection unit 102, and a pickup unit 103. The gap detection unit 101 detects the gap 19 between adjacent chips 14 based on the captured images 201, 202 captured by the imaging camera 40. The coordinate detection unit 102 pre-stores a wafer map 104 including the positions of each chip 14 on the wafer 10 of the wafer unit 17 fixed to the fixed unit 20, and detects the coordinate position of the chip 14 to be picked up from the wafer map 104, the captured image 203 acquired by having the imaging camera 40 capture the chip 14 to be picked up, which is the target for pickup, and the detection results of the position detection units 110, 120.

The pickup unit 103 stops the expansion of the tape 15 by the expansion unit 60 when a gap 192 of a predetermined width 191 or more is formed between adjacent chips 14, and controls the expansion unit 60, the push-up unit 70, the pickup mechanism 80, and the collet movement mechanism 90 so that the chip 14 to be picked up by the push-up unit 70 is pushed up and the chip 14 pushed up by the push-up unit 70 is picked up by the pickup collet 86.

The functions of the gap detection unit 101 and the pickup unit 103 are realized by the arithmetic processing unit performing arithmetic processing according to a computer program stored in the storage device. The functions of the coordinate detection unit 102 are realized by the storage device storing the wafer map 104 in advance and the arithmetic processing unit performing arithmetic processing according to a computer program stored in the storage device.

(Pick-up method)
Next, this specification will explain a pick-up method according to embodiment 1 with reference to the drawings. Fig. 4 is a flowchart showing the flow of the pick-up method according to embodiment 1. The pick-up method is a method for picking up chips 14 from tape 15 of wafer unit 17, and in embodiment 1, is a pick-up operation of pick-up device 1.

The pickup method according to the first embodiment is carried out by the pickup device 1 when pickup operation content information is input to the control unit 100 by operating a touch panel and the control unit 100 receives an instruction from the operator to start the pickup operation. The pickup operation content information includes the position of the chip 14 to be picked up from the tape 15 and the wafer map 104 described above.

That is, the position of the chip 14 to be picked up from the tape 15 is registered in advance in the control unit 100 before the pick-up method according to the first embodiment is performed. Note that in this specification, during the performance of the pick-up method, the operator may operate a touch panel or the like to select the chip 14 to be picked up from the tape 15 each time a chip 14 is picked up. As shown in FIG. 4, the pick-up method includes a fixing step 1001, an expanding step 1002, a detecting step 1003, and a pick-up step 1004.

(fixation step)
Fig. 5 is a side view, partly in section, showing the fixing step of the pick-up method shown in Fig. 4. The fixing step 1001 is a step in which the annular frame 16 of the wafer unit 17 is held by the fixing unit 20.

In the fixing step 1001, the control unit 100 controls the transport unit (not shown) to place the annular frame 16 of the wafer unit 17 on the upper surface of the frame support member 24 that has been raised by the expansion cylinder 61 and lowered by the lift cylinder 26. In the fixing step 1001, the control unit 100 controls the fixing unit 20 to raise the frame support member 24 by the lift cylinder 26, and as shown in FIG. 5, the annular frame 16 is sandwiched between the frame holding member 25 and the frame support member 24, and the wafer unit 17 is fixed by the fixing unit 20.

(Extended Step)
Fig. 6 is a side view partially in cross section showing an extended step of the pickup method shown in Fig. 4. Fig. 7 is a diagram showing an example of a captured image acquired by the imaging unit in the extended step of the pickup method shown in Fig. 4. Fig. 8 is a diagram showing another example of a captured image acquired by the imaging unit in the extended step of the pickup method shown in Fig. 4.

The expansion step 1002 is a step of expanding the tape 15 to form a gap 19 between adjacent chips 14 while imaging the wafer 10 of the wafer unit 17 including the annular frame 16 fixed in the fixing step 1001, and detecting the gap 19. In the expansion step 1002, the control unit 100 controls the moving mechanism 30 to move the fixing unit 20, and positions the center of the wafer 10 of the wafer unit 17 including the annular frame 16 held by the fixing unit 20 below the imaging camera 40 and above the push-up unit 70.

At this time, in the first embodiment, the imaging range of the imaging camera 40 on the surface 11-1 of the wafer 10 includes the central chip 14 of the wafer 10 and the chips 14 around the central chip 14. In the expansion step 1002, as shown in FIG. 6, the control unit 100 controls the expansion unit 60 to lower the fixed unit 20 by the expansion cylinder 61 while irradiating the wafer 10 with light from the light source unit 50 through the tape 15, and causes the imaging camera 40 to capture the central chip 14 of the wafer 10 of the wafer unit 17 fixed to the fixed unit 20 and the surroundings of the central chip 14, thereby acquiring the captured images 201 and 202 shown in FIG. 7 and FIG. 8 at predetermined time intervals. The captured image 201 shown in FIG. 7 is an image of the center of the wafer 10 immediately after the start of the expansion step 1002.

The captured images 201 and 202 are acquired by irradiating light from the light source unit 50 and capturing images of the chip 14 and the like with the imaging camera 40, so that the cutting groove 18 (shown as a white background in Figures 7 and 8) is brighter (has a higher amount of light) than the chip 14 (shown as a black background in Figures 7 and 8).

In the expansion step 1002, when the fixing unit 20 is lowered by the expansion cylinder 61, the upper end of the expansion drum 62 comes into contact with the tape 15 between the inner peripheral edge of the annular frame 16 of the wafer unit 17 and the outer peripheral edge of the wafer 10. In the expansion step 1002, as the fixing unit 20 is lowered, as shown in FIG. 6, the upper end of the expansion drum 62 presses the area between the inner peripheral edge of the annular frame 16 of the tape 15 and the outer peripheral edge of the wafer 10 from below to above, and the tape 15 is expanded in the planar direction. In the expansion step 1002, as a result of the expansion of the tape 15, a radial tensile force acts on the tape 15, and the interval 19 between the chips 14 gradually widens, as shown in FIG. 8.

In the expansion step 1002, the gap detection section 101 of the control unit 100 detects pixels in which the amount of light in the captured images 201, 202 exceeds a predetermined value as cutting grooves 18, and detects the gap 19 between adjacent chips 14. In the expansion step 1002, the gap detection section 101 of the control unit 100 determines whether the gap 19 between adjacent chips 14 detected by the gap detection section 101 of the control unit 100 is a gap 192 that is equal to or greater than a predetermined width 191, and controls the expansion cylinder 61 to lower the fixed unit 20 until it is determined that the gap 192 is equal to or greater than the predetermined width 191.

In the expansion step 1002, when the gap 19 between adjacent chips 14 detected by the gap detection section 101 of the control unit 100 is determined to be equal to or greater than the gap 192, which is equal to or greater than the predetermined width 191, as shown in FIG. 8, the pickup section 103 controls the expansion cylinder 61 of the expansion unit 60 to stop the descent of the fixed unit 20 and stop the expansion of the tape 15. Thus, in the first embodiment, in the expansion step 1002, the expansion of the tape 15 is stopped when a gap 192 of equal to or greater than the predetermined width 191 is formed between adjacent chips 14.

In the first embodiment, in the expansion step 1002, the gap detection unit 101 of the control unit 100 positions the imaging camera 40 above the center of the wafer 10 and detects the gap 19 based on the captured images 201, 202, so that the gap 19 between the chips 14 in the center of the wafer 10 is detected. The gap 192 of the predetermined width 191 or more is the gap between adjacent chips 14 that can be picked up by the pickup collet 86 without damaging the chips 14. In the first embodiment, the predetermined width 191 is, for example, 30 μm, but is not limited to 30 μm in the present invention. In the present invention, the predetermined width 191 is appropriately set based on the size of the chips 14, the thickness of the chips 14, and the type of the tape 15.

(Detection Step)
Fig. 9 is a side view, partially in section, showing the detection step of the pick-up method shown in Fig. 4. Fig. 10 is a diagram showing an example of a captured image acquired by the imaging unit in the detection step of the pick-up method shown in Fig. 4.

The detection step 1003 is a step in which, after the expansion step 1002 is performed and before the pick-up step 1004 is performed, the wafer 10 is imaged to detect the coordinate position of the chip 14 to be picked up. In the detection step 1003, the control unit 100 controls the moving mechanism 30 based on the measurement content information, etc. to move the fixed unit 20 while maintaining the Z-axis position of the fixed unit 20 in the expansion step 1002, and positions the chip 14 (hereinafter, indicated by the reference symbol 14-1) to be picked up from the tape 15 of the wafer unit 17 including the annular frame 16 held by the fixed unit 20 above the push-up unit 70 and below the imaging camera 40, as shown in FIG. 9.

In the detection step 1003, the control unit 100 irradiates the wafer 10 with light from the light source unit 50 through the tape 15, and causes the imaging camera 40 to capture an image of the chip 14-1 and the surroundings of the chip 14-1 on the wafer 10 of the wafer unit 17 fixed to the fixing unit 20, thereby acquiring the captured image 203 shown in FIG. 10.

The captured image 203 is obtained by irradiating light from the light source unit 50 and capturing an image of the chip 14-1 etc. by the imaging camera 40, so similar to the captured images 201 and 202, the cutting groove 18, i.e., the gap 192 (shown as a white background in FIG. 10) is brighter (has a higher amount of light) than the chips 14-1 and 14 (shown as a black background in FIG. 10). In detection step 1003, the coordinate detection section 102 of the control unit 100 detects the pixels in the captured images 201 and 202 where the amount of light exceeds a predetermined value as the cutting groove 18 and the gap 192, and detects the position of the outer edge of the chip 14-1 as the coordinate position of the chip 14-1.

Thus, in the detection step 1003, the coordinate detection section 102 of the control unit 100 positions the imaging camera 40 above the chip 14-1, which is a position corresponding to the chip 14-1 to be picked up, and detects the position of the outer edge, which is the coordinate of the chip 14-1 to be picked up, based on the captured image 203.

(Pickup step)
Fig. 11 is a cross-sectional view showing a state where a chip to be picked up is clamped between a push-up unit and a pickup collet in the pickup step of the pickup method shown in Fig. 4. Fig. 12 is a cross-sectional view showing a state where the push-up unit starts to push up the chip via the tape in the pickup step of the pickup method shown in Fig. 4. Fig. 13 is a cross-sectional view showing a state where the pickup collet sucks and holds the chip pushed up via the tape by the push-up unit in the pickup step of the pickup method shown in Fig. 4.

In the pick-up step 1004, when a gap 192 of a predetermined width 191 or more is formed between adjacent chips 14, the expansion of the tape 15 is stopped and the chip 14-1 is picked up from the wafer unit 17. In the pick-up step 1004, the pick-up section 103 of the control unit 100 maintains the Z-axis position of the fixed unit 20 in the expansion step 1002, and with the on-off valves 76 and 85 closed, controls the moving mechanism 30 to adjust the position of the fixed unit 20 based on the position of the outer edge of the chip 14-1 detected in the detection step 1003, and controls the collet moving mechanism 90 to move the pickup collet 86, thereby aligning the chip 14-1 of the wafer 10 with the push-up unit 70 and the pickup collet 86.

In the first embodiment, in the alignment, the outer edge of the chip 14-1 is aligned vertically against the outer edge of the third push-up pin 72-3, and the outer edge of the chip 14-1 is aligned vertically against the outer edge of the lower surface 88 of the pickup collet 86. Thus, in the pickup step 1004, the pickup section 103 of the control unit 100 maintains the position of the fixed unit 20 in the Z-axis direction in the expansion step 1002, thereby maintaining the state in which the expansion of the tape 15 has stopped when a gap 192 of a predetermined width 191 or more is formed between adjacent chips 14.

In the pickup step 1004, the pickup section 103 of the control unit 100 controls the push-up unit 70 to lower the push-up pins 72-1, 72-2, and 72-3, and then raises the entire push-up unit 70 so that the upper surface 78 of the outer layer 71 of the push-up unit 70 and the upper surfaces of the push-up pins 72-1, 72-2, and 72-3 come into contact with the tape 15. In the pickup step 1004, the pickup section 103 of the control unit 100 controls the collet movement mechanism 90 to lower the pickup collet 86 and bring the lower surface 88 of the pickup collet 86 into contact with the chip 14-1, so that the chip 14-1 to be picked up is sandwiched between the push-up unit 70 and the pickup collet 86 via the tape 15. In the pickup step 1004, the pickup section 103 of the control unit 100 opens the on-off valve 76 and sucks and holds the tape 15 around the chip 14-1 on the upper surface 78 of the outer layer section 71 of the push-up unit 70, as shown in FIG. 11.

12, in the pickup step 1004, the pickup section 103 of the control unit 100 controls the push-up unit 70 to raise the push-up pins 72-1, 72-2, and 72-3, and controls the collet movement mechanism 90 to raise the pickup collet 86. At this time, in the detection step 1003, the control unit 100 links the raising operation of the push-up pins 72-1, 72-2, and 72-3 and the raising operation of the pickup collet 86 so that the distance between the upper surface of the first push-up pin 72-1 and the lower surface 88 of the pickup collet 86 corresponds to the thickness of the chip 14-1 (in the first embodiment, the combined distance is the thickness of the chip 14-1 and the thickness of the tape 15).

In the pickup step 1004, the pickup section 103 of the control unit 100 controls the push-up unit 70 to stop the ascent of the third push-up pin 72-3 at the position shown in FIG. 12, and as shown in FIG. 13, stops the ascent of the second push-up pin 72-2 above the third push-up pin 72-3, and stops the ascent of the first push-up pin 72-1 above the second push-up pin 72-2. Thus, in the pickup step 1004, the push-up pins 72-1, 72-2, and 72-3 push up the chip 14-1 through the tape 15, moving the second push-up pin 72-2 and the third push-up pin 72-3 away from the chip 14-1, and in particular, the chip 14-1 is peeled off from the tape 15 on the second push-up pin 72-2 and the third push-up pin 72-3.

In the pickup step 1004, the pickup section 103 of the control unit 100 opens the on-off valve 85 as shown in FIG. 13 to suction-hold the chip 14-1 on the lower surface 88 of the pickup collet 86. In the pickup step 1004, the pickup section 103 of the control unit 100 controls the collet movement mechanism 90 to raise the pickup collet 86 and pick up the chip 14-1, which has been suction-held on the lower surface 88 of the pickup collet 86, from the tape 15. In the pickup step 1004, the pickup section 103 of the control unit 100 controls the collet movement mechanism 90 to transport the chip 14-1, which has been suction-held on the lower surface 88 of the pickup collet 86, to a predetermined destination.

When the control unit 100 of the pickup device 1 has picked up from the tape 15 all of the chips 14-1 whose positions have been entered into the measurement content information, the pickup method ends.

As described above, the pickup method according to the first embodiment detects the gap 19 between the chips 14 based on the captured images 201 and 202 captured during the expansion of the tape 15 in the expansion step 1002, and after a gap 192 of a predetermined width 191 or more is formed between adjacent chips 14, the pickup method according to the first embodiment picks up the chip 14-1 from the wafer unit 17 in the pickup step 1004. For this reason, the pickup method according to the first embodiment can form a gap 192 of a predetermined width 191 or more between adjacent chips 14 for each wafer unit 17 in the expansion step 1002 without the need to take the time to find an expansion condition for the tape 15 that can form a gap 192 of a predetermined width 191 or more between adjacent chips 14 for each wafer unit 17. In addition, since the pickup method can form a gap 192 of a predetermined width 191 or more between adjacent chips 14 for each wafer unit 17 in the expansion step 1002, the chip 14-1 can be picked up in the pickup step 1004 without being damaged.

As a result, the pickup method according to the first embodiment has the effect of being able to pick up the chip 14-1 without damaging it while minimizing the effort required.

In addition, in the pick-up method according to the first embodiment, the tape 15 is generally less likely to expand in the center of the wafer unit 17 than in the outer periphery. However, in the expansion step 1002, the center of the wafer 10 is imaged to detect that a gap 192 of a predetermined width 191 or more has been formed between adjacent chips 14 in the center. As a result, the pick-up method according to the first embodiment makes it possible to pick up chip 14-1 in a state in which a gap 192 of a predetermined width 191 or more has been formed between chips 14 across the entire wafer 10.

In addition, the pickup device 1 according to the first embodiment implements the pickup method described above, and thus has the effect of being able to pick up the chip 14-1 without damaging it while minimizing the effort required.

The present invention is not limited to the above-mentioned embodiment. In other words, various modifications can be made without departing from the gist of the present invention. In addition, in the first embodiment, the pickup device 1 is a standalone device, but in the present invention, it may form part of another device, such as a test device that measures the structural strength of the picked-up chip 14-1. In the first embodiment, the chip 14-1 is sucked and held on the lower surface 88 of the pickup collet 86 after the push-up pins 72-1, 72-2, and 72-3 push up the chip 14-1. In the present invention, the chip 14-1 may be sucked and held on the lower surface 88 of the pickup collet 86 when the push-up unit 41 and the pickup collet 86 clamp the chip 14-1 before pushing up.

REFERENCE SIGNS LIST 1 Pick-up device 10 Wafer 14, 14-1 Chip 15 Tape 16 Annular frame 17 Wafer unit 19 Spacing 20 Fixing unit 40 Imaging camera 60 Expansion unit (expansion means)
70 Push-up unit (pushing-up means)
86 Pickup collet 100 Control unit (controller)
192 Spacing of a specified width or more (specified spacing)
201, 202 Captured image 203 Captured image 1001 Fixation step 1002 Expansion step 1003 Detection step 1004 Pickup step

Claims (8)

A method for picking up chips from a wafer unit in which a wafer divided into a plurality of chips is fixed to an annular frame via a tape, comprising the steps of:
a fixing step of fixing the annular frame of the wafer unit;
an expanding step of expanding the tape to form a gap between adjacent chips and detecting the gap while imaging the wafer of the wafer unit including the annular frame fixed in the fixing step;
and a pick-up step of stopping the expansion of the tape when a predetermined gap is formed between adjacent chips, and picking up the chips from the tape to which the chips having the predetermined gap formed between adjacent chips of the wafer unit are attached. In the pick-up step, after forming a predetermined interval between adjacent chips and stopping the expansion of the tape, the tape around the chip to be picked up is sucked and held on the upper surface of the outer layer part of a push-up means for pushing up the chip, the chip is supported via the tape by a columnar first push-up pin of the push-up means and a second push-up pin which is formed in a cylindrical shape surrounding the first push-up pin and is surrounded by the outer layer part, and the chip is picked up by bringing the lower surface of a pickup collet facing the push-up means with the chip in between into contact with the chip. 2. The pickup method according to claim 1, further comprising the steps of: clamping the chip between a pickup collet and the push-up means; causing the first push-up pin and the second push-up pin to push up the clamped chip, thereby moving the outer layer and the second push-up pin away from the chip and clamping the chip between the first push-up pin and the pickup collet; peeling the tape off from the outer periphery of the chip; and holding the chip by suction on the underside of the pickup collet, and then picking up the chip held by suction on the pickup collet from the tape. 3. The pick-up method according to claim 1, wherein in the expanding step, the gap is detected at a center of the wafer. The pickup method according to any one of claims 1 to 3 , further comprising a detection step of imaging the wafer to detect the coordinate position of the chip to be picked up after performing the expansion step and before performing the pickup step. A pickup device for picking up chips from a wafer unit in which a wafer divided into a plurality of chips is fixed to an annular frame via a tape, comprising:
a fixing unit for fixing the annular frame of the wafer unit;
an imaging camera for imaging the wafer of the wafer unit including the annular frame fixed by the fixing unit;
an expansion means for pressing and expanding the tape between the inner peripheral edge of the annular frame fixed by the fixing unit and the outer peripheral edge of the wafer to form a gap between adjacent chips;
a push-up means for pushing up a chip through the tape expanded by the expanding means;
a pickup collet for picking up the chip pushed up by the push-up means;
a controller that controls at least the imaging camera, the extension means, the push-up means, and the pickup collet;
The controller detects the gap between adjacent chips based on the image captured by the imaging camera, and when a predetermined gap is formed between adjacent chips, stops expanding the tape by the expansion means, and controls the push-up means to push up the chips attached to the tape and form a predetermined gap between adjacent chips, and to pick up the chips pushed up by the push-up means with the pickup collet. 6. The pickup device according to claim 5, wherein, after forming a predetermined gap between adjacent chips and stopping the expansion of the tape, the controller suction-holds the tape around the chip to be picked up on an upper surface of the outer layer of the push-up means, supports the chip via the tape with a columnar first push-up pin of the push-up means and a second push-up pin which is formed in a cylindrical shape surrounding the first push-up pin and is surrounded by the outer layer, brings the lower surface of the pickup collet into contact with the chip to sandwich the chip between the pickup collet and the push-up means, causes the first push-up pin and the second push-up pin to push up the sandwiched chip, moves the outer layer and the second push-up pin away from the chip, and holds the chip between the first push-up pin and the pickup collet, thereby peeling the tape from the outer peripheral edge of the chip, and holds the chip by suction on the lower surface of the pickup collet, and then picks up the chip held by the pickup collet from the tape. 7. The pickup device according to claim 5, wherein the controller positions the imaging camera at a center of the wafer and detects the distance based on an image captured by the imaging camera. 8. The pickup device according to claim 5, wherein the controller positions the imaging camera at a position corresponding to a chip to be picked up and detects coordinates of the chip to be picked up based on a captured image.

Images