Pickup method and pickup device

Abstract

The present invention provides a pickup method and pickup apparatus that uses gas to push up the chips, preventing damage such as dents on the underside of the chips, and thus preventing quality degradation and yield reduction during pickup. [Solution] In a pickup device having a pickup mechanism 70 and a push-up mechanism 50, the pickup method for peeling and picking up a chip 23 from a tape 19 comprises a preparation step of preparing a push-up mechanism having a push-up section 51 in which a plurality of openings 5a to 5c from which gas can be ejected are formed, and a push-up step of ejecting gas from the openings to push up the chip 23 via the tape 19.

Description

Technical Field

[0001] The present invention relates to a method for picking up chips formed by dividing a wafer and a configuration of a pickup device.

Background Art

[0002] Conventionally, for example, as disclosed in Patent Document 1, a method for picking up chips from a divided wafer is known in a die bonder, a pickup device, etc.

[0003] In this type of pickup method, a pushing pin that moves up and down along the Z-axis direction pushes up the lower surface of the tape from below to peel off the chip, and the upper surface of the peeled chip is adsorbed and held by a collet for pickup.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the conventional method using a pushing pin and a collet as described above, since the chip is sandwiched between the pushing pin and the collet, a local load from the pushing pin acts on the back surface of the chip, and there are problems such as damage such as dents occurring on the back surface of the chip.

[0006] Such damage to the chip leads to a deterioration in the quality of the chip, and improvement has been demanded to reduce the yield.

[0007] An object of the present invention is to provide a novel pickup method and a pickup device that can solve the above problems.

Means for Solving the Problems

[0008] The problems that this invention aims to solve are as described above, and the means for solving these problems will now be explained.

[0009] According to one aspect of the present invention, a pickup method for peeling a chip from a tape and picking it up comprises a preparation step of preparing a push-up mechanism having a push-up section having a plurality of openings from which gas can be ejected, and a push-up step of ejecting the gas from the openings and pushing up the chip via the tape.

[0010] Furthermore, according to one aspect of the present invention, the invention includes a lowering step of sucking the tape through the opening and pulling the tape down.

[0011] Furthermore, according to one aspect of the present invention, the suction of the tape in the lowering step is performed starting from an opening farther from the center of the tip and sequentially at openings closer to the center of the tip.

[0012] Furthermore, according to one aspect of the present invention, the push-up step is performed with the suction surface of the collet in contact with the tip, and the pull-down step is performed with the tip held in suction by the collet.

[0013] Furthermore, according to one aspect of the present invention, there is a pickup device having a push-up mechanism having a push-up section having a plurality of openings from which gas can be ejected, and a controller for controlling the push-up mechanism, wherein the controller controls the ejection of the gas from the openings to push up the chip via the tape.

[0014] Furthermore, according to one aspect of the present invention, the push-up mechanism ejects gas at an opening near the center of the chip to push up the tape, and sucks in air at an opening further from the center of the chip than the opening from which the gas is ejected to pull down the tape.

[0015] Also, according to one aspect of the present invention, it is to have a collet having a suction surface for sucking and holding the upper surface of the chip.

Advantages of the Invention

[0016] The present invention has the following effects. That is, according to one aspect of the present invention, since the chip is pushed up by gas, damage such as dents does not occur on the lower surface of the chip, and it is possible to prevent a decrease in quality and a decrease in yield related to pickup.

[0017] Also, according to one aspect of the present invention, by performing the pulling-down step, the tape is pulled downwards, so that the chip can be peeled off more reliably, which is particularly effective when the adhesion between the chip and the tape is strong.

Brief Description of the Drawings

[0018] [Figure 1] A diagram showing an example of a frame unit. [Figure 2] A diagram showing an overview of a pickup device [Figure 3] A perspective view showing the configuration of a pushing-up mechanism and the like. [Figure 4] A plan view showing the configuration of the main body member of the pushing-up mechanism. [Figure 5] A diagram for explaining the arrangement of the chip and the pushing-up mechanism. [Figure 6] A flowchart showing each step of the pickup method. [Figure 7] (A) to (D) Diagrams showing the pickup method according to Embodiment 1. [Figure 8] (A) to (C) Diagrams showing the pickup method according to Embodiment 2.

Modes for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a view showing a wafer 13 (semiconductor wafer), which is an example of a workpiece. The wafer 13 is adhered to a tape 19 and forms a frame unit 11 integrally with an annular frame 21. The wafer 13 is cut along a planned division line 17 by a cutting device (not shown) and divided into rectangular chips 23. Note that the wafer 13 may also be divided into chips 23 by a laser processing device.

[0020] The wafer 13 is formed in a disk shape using a material such as silicon, and a plurality of devices 15 such as IC (Integrated Circuit), LSI (Large Scale Integration), and LED (Light Emitting Diode) are formed on the surface 13a side.

[0021] Note that there are no restrictions on the material, shape, structure, size, etc. of the wafer 13. For example, the wafer 13 may be a substrate formed of a material such as a semiconductor other than silicon (SiC, GaAs, InP, GaN, etc.), sapphire, glass, ceramics, resin, or metal. Also, there are no restrictions on the type, quantity, shape, structure, size, arrangement, etc. of the devices 15.

[0022] The back surface 13b side of the wafer 13 is adhered to a circular tape 19. The tape 19 is constituted by a flexible film in which an adhesive layer (paste layer) of a rubber-based or acrylic-based material is formed on a base material made of a resin such as polyolefin, polyvinyl chloride, or polyethylene terephthalate. Also, assuming the pickup of chips, the tape 19 is, for example, an ultraviolet curable tape that is cured by irradiation with ultraviolet rays. Note that the diameter of the tape 19 is larger than the diameter of the wafer 13, and the wafer 13 is adhered to the central portion of the tape 19.

[0023] An annular frame 21 made of metal or the like having a circular opening 21a at the central portion is adhered to the outer peripheral portion of the tape 19. Thereby, the wafer 13 is supported by the annular frame 21 via the tape 19 in a state of being disposed inside the opening 21a.

[0024] Figure 2 is a diagram illustrating the overview of the pickup device 2. A temporary storage platform 4a is provided at one end of the front side (upper right side in Figure 2) of the base 4 of the pickup device 2, and the frame unit 11 (Figure 1) is transported to the temporary storage platform 4a by a transport device (not shown).

[0025] The frame unit, transported to the temporary stand 4a, is supplied to the frame fixing mechanism 14 by a transfer mechanism (not shown). The frame fixing mechanism 14 includes a frame support portion 16 that supports the lower surface of the annular frame and a frame pressing portion 18 that contacts the upper surface of the annular frame. The frame support portion 16 and the frame pressing portion 18 are each formed in an annular shape corresponding to the shape of the annular frame 21 (Figure 1) and are arranged to overlap each other. The frame support portion 16 is configured to be movable along the Z-axis direction (vertical direction, up and down direction). When the frame support portion 16 is moved upward, the annular frame is sandwiched and fixed between the frame support portion 16 and the frame pressing portion 18.

[0026] The frame fixing mechanism 14 is supported by a positioning mechanism 30 that controls the position of the frame fixing mechanism 14. The positioning mechanism 30 includes an X-axis movement mechanism 32 that moves the frame fixing mechanism 14 along the X-axis direction and a Y-axis movement mechanism 42 that moves the frame fixing mechanism 14 along the Y-axis direction. The horizontal position of the frame fixing mechanism 14 is controlled by the X-axis movement mechanism 32 and the Y-axis movement mechanism 42.

[0027] The X-axis movement mechanism 32 includes a pair of guide rails 34 arranged along the X-axis direction on a base 4. A ball screw 36 is provided between the pair of guide rails 34, positioned approximately parallel to the pair of guide rails 34. A pulse motor 38 for rotating the ball screw 36 is connected to one end of the ball screw 36.

[0028] A movable block 40 is slidably positioned on a pair of guide rails 34. A nut (not shown) is provided on the underside (back side) of the movable block 40, and this nut is screwed onto a ball screw 36. When the ball screw 36 is rotated by the pulse motor 38, the movable block 40 moves along the pair of guide rails 34 in the X-axis direction.

[0029] The Y-axis movement mechanism 42 includes a pair of guide rails 44 arranged along the Y-axis direction on the movement block 40. A ball screw 46 is provided between the pair of guide rails 44, positioned approximately parallel to the pair of guide rails 44. A pulse motor 48 for rotating the ball screw 46 is connected to one end of the ball screw 46.

[0030] A frame fixing mechanism 14 is slidably positioned on a pair of guide rails 44. A nut (not shown) is provided at the support portion of the frame fixing mechanism 14, and this nut is screwed onto a ball screw 46. When the ball screw 46 is rotated by the pulse motor 48, the frame fixing mechanism 14 moves along the pair of guide rails 44 in the Y-axis direction.

[0031] As shown in Figure 2, the movable block 40 is constructed in a plate shape, and an opening 41 is formed that penetrates vertically at a position below the frame fixing mechanism 14. Through this opening 41, it is possible to push it up from below by the push-up mechanism 50, which will be described later.

[0032] A rectangular opening 4b is provided in the area between the pair of guide rails 36 on the base 4. Inside this opening 4b is a push-up mechanism 50 that pushes up the chip 23 (Figure 1) contained in the wafer 13 of the frame unit 11 from the bottom side upward. The push-up mechanism 50 is connected to a lifting mechanism (not shown) composed of an air cylinder or the like, and moves up and down along the Z-axis direction.

[0033] With the frame unit 11 (Figure 1) fixed by the frame fixing mechanism 14, the positioning mechanism 30 moves the frame fixing mechanism 14 along the X-axis, so that the frame unit 11 is positioned on the opening 4b. Then, the wafer 13 is imaged with the wafer imaging camera 6, and predetermined chips contained in the wafer 13 are sequentially positioned directly above the push-up mechanism 50 based on the imaged image, and then pushed upward by the push-up mechanism 50.

[0034] The chip, detached from the tape by the push-up mechanism, is picked up by its upper surface being held by the collet 76 of the pickup mechanism 70. The pickup mechanism 70 is configured to be moved and positioned in the YZ plane by the YZ movement mechanism 80. The YZ movement mechanism 80 includes a Y-axis movement mechanism 82 that moves the pickup mechanism 70 along the Y-axis direction and a Z-axis movement mechanism 92 that moves the pickup mechanism 70 along the Z-axis direction.

[0035] The Y-axis movement mechanism 82 includes a pair of guide rails 84 arranged along the Y-axis direction. A ball screw 86 is provided between the pair of guide rails 84, positioned approximately parallel to the pair of guide rails 84. A pulse motor 88 for rotating the ball screw 86 is connected to one end of the ball screw 86.

[0036] A pair of guide rails 84 have movable blocks 90 mounted on them so as to be slidable. The movable blocks 90 are also provided with a nut portion (not shown), which is screwed onto a ball screw 86. When the pulse motor 88 rotates the ball screw 86, the movable blocks 90 move along the pair of guide rails 84 in the Y-axis direction.

[0037] The Z-axis movement mechanism 92 includes a pair of guide rails 94 arranged along the Z-axis direction on the side of the movement block 90. ​​A ball screw 96 is provided between the pair of guide rails 94, positioned approximately parallel to the pair of guide rails 94. A pulse motor 98 for rotating the ball screw 96 is connected to one end of the ball screw 96.

[0038] A movable base 72 of the pickup mechanism 70 is slidably mounted on a pair of guide rails 94. The movable base 72 is also provided with a nut (not shown), which is screwed onto a ball screw 96. When the ball screw 96 is rotated by the pulse motor 98, the movable base 72 moves along the pair of guide rails 94 in the Z-axis direction.

[0039] Furthermore, the pickup mechanism 70 is provided with an X-axis movement mechanism 74c that moves the collet 76 in the X-axis direction. As a result, the pickup mechanism 70 is moved by the YZ movement mechanism 80, which moves the collet 76 in the YZ axis direction, and the X-axis movement mechanism 74c moves the collet 76 in the X axis direction.

[0040] The chips picked up by the collet 76 are transported, for example, to a designated place on the chip tray 501. Alternatively, they may be transported directly for subsequent processes such as bonding.

[0041] Next, the configuration of the push-up mechanism 50 shown in Figures 3 and 4 will be described. The push-up mechanism 50 is configured to have a push-up section 51, each having a plurality of openings from which gas can be ejected.

[0042] To explain in more detail, as shown in Figures 3 and 4, the push-up mechanism 50 has a cylindrical main body member 52, and a plurality of openings 5a to 5c are formed on the upper end surface 52a of the main body member 52, and the push-up portion 51 is formed by this upper end surface 52a and the openings 5a to 5c.

[0043] The main body member 52 is connected to a lifting mechanism (not shown) and is controlled to move vertically by a controller 10 that controls various mechanisms of the pickup device 2 (Figure 2). The main body member 52 is cylindrical in shape, and its upper end surface 52a forms a circular horizontal surface. Alternatively, the main body member 52 may be rectangular in shape, and its upper end surface 52a may form a rectangular horizontal surface.

[0044] Multiple openings 5a to 5c are formed in the circumferential direction on the upper end surface 52a, and each opening 5a to 5c is arranged concentrically with the axis of the main body member 52 as the center 52c. In this embodiment, it is configured to have an annular third opening 5c ​​located on the outermost circumference, an annular second opening 5b located inward and closer to the center 52c than the third opening 5c, and a circular third opening 5a that is closer to the center 52c than the second opening 5b.

[0045] The number of openings should be at least two, arranged concentrically with the center 52c. For example, another annular opening may be provided outside the third opening 5c. In addition to being annular like the third opening 5c, the openings may also be rectangular in shape in plan view, or multiple non-contiguous circular holes may be arranged in the circumferential direction. Furthermore, another annular opening may be provided outside the third opening 5c ​​and dedicated to suction, or an outer cylinder may be provided outside the main body member 52 that moves up and down together with the main body member 52, with a suction opening on the upper end surface of the outer cylinder.

[0046] As shown in Figure 3, the main body member 52 has ventilation passages 54a to 54c that lead to each of the openings 5a to 5c. Each ventilation passage 54a to 54c is connected to control valves 56a to 56c located outside the main body member 52 via external ventilation passages 55a to 55c. Each control valve 56a to 56c is connected to a gas source 57 capable of supplying high-pressure gas and a suction source 58 for drawing in gas, respectively, and is connected to either the gas source 57 or the suction source 58 by switching controlled by the controller 10. The gas can be, for example, air or an inert gas.

[0047] Furthermore, the ventilation passages 54a to 54c are not particularly limited as long as they lead to each of the openings 5a to 5c, and are not limited to the form formed vertically along the main body member 52 as shown in Figure 3.

[0048] As shown in Figure 3, the main body member 52 pushes up the chip 23 from below the tape 19, and the third opening 5c, located on the outermost part of the upper end surface 52a, is configured to be positioned inside the chip 23.

[0049] Figure 5 is a top view of the chip 23 attached to the tape 19. As will be described in more detail later, the chip is positioned so that the center 23c of the chip 23 coincides with the center 52c of the main body member 52.

[0050] With the above configuration, the switching between gas ejection and gas suction from each of the openings 5a to 5c can be performed by controlling the control valves 56a to 56c with the controller 10. As a result, the push-up mechanism 50 shown in Figure 3 can eject gas from the first opening 5a, which is closer to the center 23c of the tip 23, to push up the tape 19, and suction air from the third opening 5c, which is further from the center 23c of the tip 23 than the first opening 5a from which the gas is ejected, to pull down the tape 19.

[0051] As shown in Figure 3, during pickup, the tip 23 is pushed up by the push-up portion 51 of the push-up mechanism 50, as will be described in more detail later, and the pushed-up tip 23 is held by the collet 76 of the pickup mechanism 70.

[0052] The collet 76 has a roughly rectangular parallelepiped shape, and an adsorption surface 76a is formed on its lower surface for adsorbing and holding the surface 23a of the tip 23. A suction hole (not shown) is formed in the adsorption surface 76a, and the suction hole is connected to a suction source 76f via a suction passage 76d and a control valve 76e. The control valve 76e is opened and closed by the controller 10, thereby controlling the on / off of adsorption and holding by the adsorption surface 76a. The collet 76 may have a shape substantially identical to the surface 23a of the tip 23, or it may have a surface with a larger area than the surface 23a of the tip 23. Furthermore, the adsorption surface 76a may be configured as a rectangular adsorption surface to adsorb the entire surface 23a of the tip 23, or it may be configured as a circular adsorption surface.

[0053] Next, the pickup method using the above device configuration will be explained in the order of each step in the flowchart shown in Figure 6. Note that the operation of the various mechanisms in each of the following steps can be performed by automatic control by the controller 10 (Figure 3). [Examples]

[0054] <Preparation Steps> As shown in Figures 7(A) and 7(B), the step is to prepare a push-up mechanism 50 having a push-up section 51 in which a plurality of openings 5a to 5c from which gas can be ejected are formed.

[0055] Specifically, as shown in Figure 7(A), the positioning mechanism 30 (Figure 2) aligns the chip 23 to be picked up so that it is positioned directly above the push-up mechanism 50 (main body member 52). Next, as shown in Figure 7(B), the main body member 52 is raised, and the push-up portion 51 is brought into contact with the lower surface of the tape 19.

[0056] Furthermore, as shown in Figure 7(A), the YZ movement mechanism 80 (Figure 2) and the X-axis movement mechanism 74c (Figure 2) are used to align the collet 76 so that it is positioned directly above the tip 23 to be picked up. Next, as shown in Figure 7(B), the collet 76 is lowered so that the suction surface 76a comes into contact with the upper surface of the tip 23, and then suction is started to pick up the tip 23 onto the suction surface 76a.

[0057] <Push-up step> As shown in Figure 7(C), this step involves ejecting gas from openings 5a and 5b to push up the tip 23 via the tape 19.

[0058] Specifically, as shown in Figure 3, control valves 56a and 56b are controlled to supply gas from the gas source 57 to the openings 5a and 5b through the ventilation passages 54a and 54b. As a result, gas is ejected from the openings 5a and 5b, and the tape 19 is pushed up by the gas. At the same time, the collet 76 is also raised to pull up the tip 23.

[0059] Furthermore, the gas ejection volume and pressure from each of the openings 5a and 5b may be set to be different. For example, the gas ejection volume from the outermost opening 5b may be set to be less than that from the opening 5a closer to the center, or the gas pressure from the outermost opening 5b may be set to be lower than that from the opening 5a closer to the center.

[0060] Furthermore, the outermost opening 5c ​​is connected to a suction source 58 by controlling a control valve 56c, as shown in Figure 3, and the tape 19 near the outer circumference of the tip 23 is held in place by suction. This allows the peeling of the outer circumference of the tip 23 to begin.

[0061] <Peeling step> As shown in Figure 7(D), this is the step in which the chip 23 is peeled off from the tape 19.

[0062] Specifically, during the push-up step, the tape 19 is pushed up by the gas, and the tip 23 is held in place by the collet 76, causing the lower surface of the tip 23 to peel off from the tape 19.

[0063] Furthermore, it is preferable that the upward distance and speed of the collet 76 be linked to the upward distance and speed at which the tape (tip) is pushed up by the gas ejected. For example, by making the upward distance and speed of the collet the same as the upward distance and speed of the tip due to the gas ejection, it is possible to prevent the formation of dents.

[0064] Alternatively, the tip may be made to contact the collet 76 without being held in place by suction, and then the collet may be used to hold the tip in place by suction after the push-up step has been performed.

[0065] Furthermore, by stopping the gas ejection after the tape 19 is pushed up, the tape 19 returns to its state before being pushed up. This return causes the tape 19 to move downward, which in turn promotes peeling.

[0066] In the above process up to peeling, the chip 23 is pushed up by gas, so no damage such as dents occurs on the underside of the chip 23, and quality degradation and yield reduction related to pickup can be prevented. [Examples]

[0067] This second embodiment is modified by adding a downward step to the upward step and peeling step of the first embodiment.

[0068] <Downgrade Steps> This step involves using openings 5a and 5b to suck in the tape 19 and pull it down.

[0069] First, as shown in Figure 8(A), a lifting step is performed in which gas is ejected from openings 5a and 5b to push up the tip 23 via the tape 19. The state in which the tip 23 is held by suction with the collet 76 is maintained. The tape is held by suction through opening 5c.

[0070] Next, as shown in Figures 3 and 8(B), the control valve 56b provided in the external ventilation passage 55b leading to the opening 5b near the outer circumference of the tip 23 is switched to connect the external ventilation passage 55b to the suction source 58 and start suction at the second opening 5b.

[0071] As a result, as shown in Figure 8(B), the tape 19 above the second opening 5b is pulled down by suction, closing the second opening 5b. This pulling down causes the tape 19 to peel off the tip 23.

[0072] Next, as shown in Figures 3 and 8(C), the control valve 56a provided in the external ventilation passage 55a leading to the first opening 5a, which is located closest to the center of the tip 23, is switched to connect the external ventilation passage 55a to the suction source 58 and start suction at the first opening 5a.

[0073] As a result, as shown in Figure 8(C), the tape 19 above the first opening 5a is sucked down and pulled to close the first opening 5a. This pulling down causes the tape 19 to completely detach from the tip 23. As is clear from the above explanation, the suction of the tape 19 is performed starting from the opening 5b furthest from the center of the tip 23, and then sequentially at the opening 5a closer to the center of the tip.

[0074] By performing the above lowering step, the tape 19 can be pulled downwards, which makes it possible to more reliably remove the chip 23, and is particularly effective when the adhesion between the chip 23 and the tape 19 is strong. [Explanation of symbols]

[0075] 2. Pickup device 5a First opening 5b Second opening 5c Third opening 10 Controllers 19 Tapes 23 chips 30 mechanism 32 axis movement mechanism 50 Push-up mechanism 51 Push-up section 52 Main body components 52a Upper end surface 52c center 54a Ventilation channel 54b Ventilation channel 54c ventilation channel 55a External ventilation channel 55b External ventilation channel 55c External ventilation channel 56a Control valve 56b Control valve 56c control valve 57 Gas sources 58 Suction source 70 Pickup Mechanism 76 Colette 76a Adsorption surface 76d Suction channel 76e Control Valve 76f Suction source Hk peeling point

Claims

1. A pickup method that involves peeling the chip off the tape and picking it up, A preparation step of preparing a lifting mechanism having a lifting section having multiple openings formed therein, each capable of ejecting gas, A pickup method comprising a push-up step of ejecting the gas from the opening and pushing the chip up via the tape.

2. A lowering step in which the tape is sucked up at the opening and the tape is pulled down, The pickup method according to claim 1, characterized by comprising the above.

3. The suction of the tape in the lowering step begins at the opening furthest from the center of the tip and is carried out sequentially at the openings closer to the center of the tip. The pickup method according to feature 2.

4. The pushing-up step is performed with the suction surface of the collet in contact with the tip. The lowering step is performed while the tip is held in place by the collet. The pickup method according to any one of claims 1 to 3.

5. A lifting mechanism having a lifting section with multiple openings formed therein, each capable of ejecting gas, A pickup device having a controller for controlling the push-up mechanism, A pickup device in which the controller controls the ejection of the gas from the opening to push the chip up via the tape.

6. The push-up mechanism is, At the opening near the center of the chip, the gas is ejected to push up the tape, At the opening further from the center of the tip than the opening from which the gas is ejected, air is drawn in to pull the tape down. The pickup device according to feature 4.

7. A collet having a suction surface for adsorbing and holding the upper surface of the chip, The pickup device according to claim 5 or 6, characterized by having the following features.

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