Sheet peeling device and sheet peeling method

Abstract

To provide a sheet peeling device capable of reducing cost required for peeling and capable of suppressing damage of plate-like members such as wafers.SOLUTION: A sheet peeling device 1 includes: a holding table 10 holding a plate-like member W to which a sheet S is attached; a tip 21; a first sheet holding part 30 capable of holding a peel start edge S1 of the sheet S; and second sheet holding parts 40, 40 provided along a width direction of the sheet S. The tip 21 is engageable from a horizontal direction with respect to a side end face S2 by a horizontal movement, and hooks the sheet S by an upward movement to be able to form the peel start edge S1. The first sheet holding part 30 can raise upwards the peel start edge S1 by an upward movement while crimping the peel start edge S, and the second sheet holding parts 40, 40 can peel the sheet S by crimping both sides of the peel start edge S1 in a width direction along the width direction and moving toward the other end side in a peeling direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sheet peeling device and a sheet peeling method. [Background technology]

[0002] Conventionally, a semiconductor wafer (also referred to as a wafer) has a circuit pattern formed on its front side, and then its back side is ground or otherwise thinned. Furthermore, a protective sheet (also referred to as a protective tape or B / G tape) is attached to the front side of the wafer to protect the circuit pattern during grinding or otherwise processing of the back side of the wafer. The wafer with the attached protective sheet undergoes back grinding, and then the protective sheet is peeled off. The wafer from which the protective sheet has been peeled off is then diced into chips. The protective sheet is peeled off by attaching a peeling tape to the protective sheet and peeling off the protective sheet together with the peeling tape (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 2994356 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, the protective tape removal device described in Patent Document 1 mentioned above adsorbs and holds the wafer on an adsorption stage (corresponding to a holding table) with the protective tape (corresponding to a protective sheet) facing up, and then attaches a removal tape onto the protective tape, and then reels the removal tape off the wafer.

[0005] However, the protective tape peeling device described in Patent Document 1 requires the attachment of a peeling tape to the protective tape when peeling the protective tape, resulting in the additional cost of the peeling tape. Furthermore, the protective tape peeling device requires the attachment of the peeling tape to the suction stage (equivalent to the holding table). To prevent this, a fluororesin-treated mask plate must be placed on the suction table or a non-adhesive treatment such as fluororesin must be applied to the area where the adhesive surface of the peeling tape comes into contact. Therefore, these additional costs are required. Furthermore, with the recent trend toward thinner wafers, if the peeling tape comes into contact with the protruding portion of the protective tape, the wafer may be damaged by chipping or other factors. Furthermore, after the backgrinding process, the protective tape is contaminated with grinding debris and other contaminants, resulting in poor adhesion when the peeling tape is attached to the protective tape. This has led to the problem of the peeling tape coming off during protective tape peeling, resulting in poor peeling.

[0006] Therefore, an object of the present invention is to provide a sheet peeling device and a sheet peeling method that can reduce the cost required for peeling and can prevent damage to plate-like members such as wafers. [Means for solving the problem]

[0007] (1) A sheet peeling device provided to solve the above-mentioned problems is a sheet peeling device that peels a sheet attached to a plate-like member from one end side to the other end side, and is characterized in that it has a holding table that holds the plate-like member so that the sheet is on the upper side, at least one pointed end that is arranged to face horizontally against the side end face of the sheet at the peel start side, and a sheet holding unit that can hold one end of the sheet at the peel start side, wherein the pointed end can engage with the side end face from the horizontal direction by horizontal movement relative to the holding table, and can hook the sheet to form a peel start end by moving upward relative to the holding table while engaged with the side end face, and the sheet holding unit moves upward relative to the holding table while clamping the peel start end, thereby pulling the peel start end upward from the top surface of the plate-like member, and peeling the sheet from the plate-like member by moving relative to the holding table toward the other end side in the peel direction.

[0008] The above-described sheet peeling device has a pointed end that faces horizontally toward the side edge surface of the sheet at the peel start side and can engage with the side edge surface of the sheet from the horizontal direction. That is, the pointed end is parallel to the sheet surface. Therefore, the pointed end is prevented from penetrating in a direction intersecting the sheet surface and contacting the plate-like member. This prevents damage to the plate-like member. Furthermore, since the pointed end can pierce and engage the side edge surface of the sheet from the horizontal direction, damage to the wafer can be prevented. Here, the pointed end can be various types of sharp-tipped objects such as a needle, scraper, or blade. When the sheet is thin, it is desirable to use a needle or other object with a small tip area. Furthermore, the number of pointed ends can be adjusted appropriately according to the width of the sheet. When multiple pointed ends are provided, it is desirable to evenly distribute them along the width direction of the sheet. By providing multiple pointed ends, the load applied during peeling can be evenly distributed, thereby evenly distributing the load applied to the plate-like member.

[0009] (2) In the sheet peeling device of the present invention described above, the sheet holding portion has a first sheet holding portion and a second sheet holding portion arranged along a width direction intersecting the peeling direction via the first sheet holding portion, and the first sheet holding portion is capable of clamping the peeling starting end and lifting the peeling starting end upward from the top surface of the plate-like member by moving upward relative to the holding table, and the pair of second sheet holding portions clamp both widthwise sides of the lifted peeling starting end along the width direction and move relative to the holding table toward the other end in the peeling direction, thereby peeling the sheet from the plate-like member.

[0010] According to this configuration, the peel start end can be formed by hooking the side edge of the sheet on the pointed end and pulling it upward, and the peel start end can be clamped by the first sheet holding portion. Therefore, the pointed end can be prevented from coming off the side edge, ensuring reliable formation of the peel start end. Furthermore, both widthwise sides of the formed peel start end can be clamped along the widthwise direction by a pair of second sheet holding portions. Furthermore, while the sheet is clamped by the pair of second sheet holding portions, the sheet can be pulled and peeled. Therefore, even when peeling a wide sheet, the sheet can be prevented from being squeezed toward the center when pulled. This reduces the load on the plate-shaped member and prevents damage to the plate-shaped member. Furthermore, since the sheet is reliably held by the second sheet holding portion, it is possible to prevent the sheet from coming off during peeling, resulting in peeling failure. Here, it is desirable that the first sheet holding portion and the second sheet holding portion have a roughened surface, such as a knurled surface, on the surface that contacts the sheet. This prevents the sheet from falling off the first sheet holding portion and the second sheet holding portion.

[0011] Furthermore, the above-described sheet peeling device can peel off the sheet without using peeling tape. Therefore, the cost of peeling tape can be reduced. Furthermore, since the above-described sheet peeling device does not use peeling tape, the peeling tape does not stick to the holding table. Furthermore, even if the sheet surface is dirty, the sheet can be peeled off reliably.

[0012] (3) The sheet peeling device of the present invention described above may be configured such that the pointed ends are arranged in a pair at a distance from each other in a width direction intersecting the peeling direction of the sheet, and the peeling starting end is formed by engaging each of the pair of pointed ends with the side end surface and moving upward relative to the holding table.

[0013] According to this configuration, the pair of pointed ends can engage the sheet from both sides in the width direction. That is, the sheet and the pointed ends can be engaged in a balanced manner from both sides in the width direction. Therefore, disengagement is suppressed. Furthermore, the peel start end can be formed accurately and reliably.

[0014] (4) In the sheet peeling device of the present invention described above, the first sheet holding portion may be disposed between the pair of pointed ends.

[0015] With this configuration, the first sheet holding portion can be positioned without interfering with the pair of pointed ends, thereby allowing the peel start end formed by the pointed ends to be held by the first sheet holding portion more reliably and quickly.

[0016] (5) The sheet peeling device of the present invention described above may preferably have a measuring unit capable of measuring the height of the holding surface of the holding table and the thickness of each of the plate-like member and the sheet, and a control unit that controls the height of the tip based on the information measured by the measuring unit.

[0017] This configuration can prevent the plate-shaped member from coming into contact with the pointed end. This prevents the plate-shaped member from being damaged. Furthermore, even if the plate-shaped member is thin (for example, 100 μm thick), the pointed end can reliably engage with the sheet. This allows the sheet to be reliably peeled off from the plate-shaped member.

[0018] (6) The sheet peeling device of the present invention described above preferably has a pressure plate that presses the outer periphery of the plate-shaped member on the peeling starting end side from above toward the holding table, and as the peeling starting end is formed, the sheet is peeled off from the plate-shaped member while the outer periphery is pressed by the pressure plate.

[0019] With this configuration, even if the plate-shaped member is thinned, it is possible to prevent the plate-shaped member from being pulled by the sheet and lifting up, thereby preventing the plate-shaped member from being damaged or its outer edge from chipping.

[0020] (7) The sheet peeling device of the present invention may include a heating unit for heating either or both of the holding table and the pointed end.

[0021] According to this configuration, the adhesive of the sheet is softened, which reduces resistance when peeling off, making it possible to easily peel off the sheet and preventing damage to the plate-like member.

[0022] (8) In the sheet peeling device of the present invention described above, the plate-like member may be a semiconductor wafer, and the sheet may be a protection sheet for back grinding.

[0023] This configuration provides a sheet peeling device suitable for peeling off a protective sheet (also called a protective tape or a BG tape) that protects the surface of a semiconductor wafer. It also provides a sheet peeling device that can reliably peel off even a protective sheet that has become contaminated by the backgrinding process.

[0024] (9) A sheet peeling method provided to solve the above-mentioned problems is a sheet peeling method for peeling a sheet attached to a plate-like member from one end side to the other end side, characterized by the following steps: a plate-like member holding step for holding the plate-like member on a holding table so that the sheet is on the upper side; a tip engaging step for engaging at least one tip horizontally with the side end face of the sheet at the peel start side from the horizontal direction; and a peel start forming step for lifting the sheet upward by moving the tip relatively upward with respect to the holding table to form a peel start end, and then peeling the sheet from the plate-like member by pulling the peel start end while it is clamped by a sheet holding part that clamps it.

[0025] In the above-described sheet peeling method, the pointed end can be engaged horizontally with the side end surface of the sheet at the peel start side in the pointed end engagement step. Therefore, the pointed end can be prevented from penetrating through the sheet surface and contacting the plate-shaped member in a direction intersecting the sheet surface. This prevents damage to the plate-shaped member. Furthermore, the peel start end can be reliably formed in the peel start end formation step. The above-described sheet peeling method peels the sheet from the plate-shaped member by pulling the peel start end formed in this manner while clamping it with the sheet holding portion. Therefore, the above-described sheet peeling method allows the sheet to be peeled without using a peel tape, thereby reducing the cost of the peel tape. Furthermore, since the above-described sheet peeling method does not use a peel tape, the peel tape does not stick to the holding table. Furthermore, the sheet can be reliably peeled even if the sheet surface is dirty.

[0026] (10) The above-mentioned sheet peeling method may preferably peel the sheet from the plate-like member by sequentially performing the following steps after the peeling starting end forming step: a first sheet holding step in which the peeling starting end is clamped by a first sheet holding portion constituting the sheet holding portion; a sheet raising step in which the peeling starting end is clamped by the first sheet holding portion and pulled upward to widen the gap between the plate-like member and the sheet; a second sheet holding step in which both widthwise sides of the raised peeling starting end are clamped by a pair of second sheet holding portions constituting the sheet holding portion and formed along the width direction, and the clamping of the peeling starting end by the first sheet holding portions is released; and a sheet peeling step in which the sheet is peeled from the plate-like member by moving the second sheet holding portions relative to the holding table toward the other end in the peeling direction while clamping both widthwise sides of the peeling starting end.

[0027] According to the above-described method, the peeling start end can be reliably held in the first sheet holding step, and the subsequent sheet raising step can reliably form a sheet margin to be clamped by the second sheet holding portion. This reduces peeling errors. Furthermore, the second sheet holding step allows both widthwise sides of the raised peeling start end to be clamped by a pair of second sheet holding portions formed along the widthwise direction. Therefore, in the subsequent sheet peeling step, the sheet is prevented from being squeezed toward the center when pulled. This reduces the load on the plate-shaped member and prevents damage to the plate-shaped member. Furthermore, because the sheet is reliably held by the second sheet holding portions, it is possible to prevent the sheet from coming loose during peeling, resulting in peeling failure. Furthermore, because the second sheet holding portions clamp both widthwise sides of the peeling start end, the clamping of the first sheet holding portion by the first sheet holding portion is released, allowing the sheet to be transferred from the first sheet holding portion to the second sheet holding portion while avoiding interference between the first and second sheet holding portions.

[0028] (11) The sheet peeling method of the present invention described above may preferably include, prior to the tip engagement step, a measurement step of measuring the height of the holding surface of the holding table and the thicknesses of the plate-like member and the sheet using a measuring unit, and a positioning step of positioning the tip relative to the side end surface based on the measurement results by the measuring unit.

[0029] This configuration can prevent the plate-shaped member from coming into contact with the pointed end. This prevents the plate-shaped member from being damaged. Furthermore, even if the plate-shaped member is thin (for example, 100 μm thick), the pointed end can reliably engage with the sheet. This allows the sheet to be reliably peeled off from the plate-shaped member.

[0030] (12) In the sheet peeling method of the present invention described above, in the peeling start end forming step, it is preferable that a plate-like member pressing step is carried out in which, after the peeling start end is formed, the outer periphery of the plate-like member on the peeling start end side is pressed from above toward the holding table by a pressing plate.

[0031] With this configuration, even if the plate-shaped member is thinned, it is possible to prevent the plate-shaped member from being pulled by the sheet and lifting up, thereby preventing the plate-shaped member from being damaged or its outer edge from chipping.

[0032] (13) In the sheet peeling method of the present invention, a heating step of heating either or both of the holding table and the tip may be carried out prior to the tip engaging step.

[0033] According to this configuration, the adhesive of the sheet is softened, which reduces resistance when peeling off, making it possible to easily peel off the sheet and preventing damage to the plate-like member.

[0034] (14) In the sheet peeling method of the present invention, the plate-like member may be a semiconductor wafer, and the sheet may be a protective sheet for back grinding.

[0035] This configuration provides a sheet peeling method suitable for peeling off a protective sheet (also called protective tape or BG tape) that protects the surface of a semiconductor wafer. Furthermore, even a protective sheet with dirt on its surface due to the back grinding process can be reliably peeled off. [Effects of the Invention]

[0036] According to the present invention, it is possible to provide a sheet peeling device and a sheet peeling method that can reduce the cost required for peeling and prevent damage to plate-like members such as wafers. [Brief explanation of the drawings]

[0037] [Figure 1] 1 is a partially omitted plan view showing an embodiment of a sheet peeling device of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along the line AA in FIG. [Figure 3] FIG. 2 is an explanatory diagram of a measuring unit constituting the sheet peeling device of the present invention. [Figure 4] 4A and 4B are explanatory views of the operation of the sheet peeling device of the present invention. [Figure 5] 5(c) and 5(d) are explanatory views of the operation of the sheet peeling device of the present invention. [Figure 6] 10(e) and 10(f) are explanatory views of the operation of the sheet peeling device of the present invention. [Figure 7] 5A to 5C are explanatory diagrams illustrating the operation of the sheet peeling device of the present invention. [Figure 8] 5A to 5C are explanatory diagrams illustrating the operation of the sheet peeling device of the present invention. [Figure 9] 5A to 5C are explanatory diagrams illustrating the operation of the sheet peeling device of the present invention. [Figure 10] 5A to 5C are explanatory diagrams illustrating the operation of the sheet peeling device of the present invention. [Figure 11] 5A to 5C are explanatory diagrams illustrating the operation of the sheet peeling device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0038] An embodiment of a sheet peeling device 1 according to the present invention will be described in detail with reference to Figures 1 to 11. In this embodiment, the plate-like member is a semiconductor wafer W (also referred to as wafer W), and the case of peeling off a protective sheet S for back grinding attached to the surface of the wafer W will be described as an example. Note that in each figure, the thickness of the protective sheet S and the wafer W is exaggerated.

[0039] The protective sheet S (also referred to as sheet S) to be peeled in this embodiment is attached to the wafer W to protect the circuit pattern surface formed on the wafer W, for example, when grinding the backside of the wafer W. The protective sheet S is formed by laminating an adhesive layer on a substrate such as EVA (ethylene-vinyl acetate copolymer) or PET (polyethylene terephthalate). Before attachment, the release sheet is peeled off from the protective sheet S, and the adhesive side is attached to the wafer W. The protective sheet S is attached to the circuit pattern surface of the wafer W either by attaching a sheet cut to the shape of the wafer W in advance, or by attaching the protective sheet S to the semiconductor wafer W and then cutting it to the shape of the semiconductor wafer W. The protective sheet S uses, for example, an ultraviolet-curing adhesive, and its adhesive strength is reduced by irradiation with ultraviolet light before peeling.

[0040] 1 and 2, the sheet peeling device 1 includes a holding table 10 that holds the wafer W, a peeling start end forming unit 20, a first sheet holding section 30 that holds the peeling start end S1, and a pair of second sheet holding sections 40, 40 provided on both sides in the width direction of the protective sheet S. In addition to the above, the sheet peeling device 1 also includes a measuring section 50, a control section 60 that controls the sheet peeling device 1, etc.

[0041] As shown in FIG. 2, the holding table 10 includes a circular suction portion 11 formed to match the outer shape of the wafer W, a table frame 12 surrounding the suction portion 11, and a pressing plate 13 for pressing the outer edge of the wafer W.

[0042] The suction unit 11 is formed, for example, from a porous ceramic material or a plate material having a plurality of suction holes. The suction unit 11 can generate a suction force on its upper surface by using an appropriate vacuum pump (not shown). This allows the suction unit 11 to hold the wafer W with the protective sheet S facing upward. The suction unit 11 also has a plurality of regions (not shown) according to the outer diameter of the wafer W to be suctioned, and the region in which the suction force is generated can be switched. The suction unit 11 can suction-hold the wafer W by generating a suction force in the region where the wafer W is placed.

[0043] The suction unit 11 also incorporates, for example, a sheet-like heater 15 (also referred to as the heating unit 15), which can heat the held wafer W. This heats the adhesive of the protective sheet S, softening the adhesive and reducing resistance during peeling. This makes it easier to peel off the protective sheet S, as described below. The heating temperature of the heater 15 can be changed as appropriate depending on the composition of the protective sheet S and the adhesive.

[0044] The table frame 12 is formed to surround the suction portion 11, and prevents suction leakage from the suction portion 11. The table frame 12 can be moved horizontally along the peeling direction of the sheet S together with the suction portion 11 by an appropriate drive source (not shown). The upper surface of the table frame 12 is formed flush with the upper surface of the suction portion 11, and can be used as a reference when positioning the needles 21, which will be described later.

[0045] The pressure plate 13 is provided at one end of the holding table 10 on the peel start side. The pressure plate 13 can be moved horizontally along the peel direction and up and down by an appropriate drive source (not shown). The pressure plate 13 can also press the outer periphery of the wafer W on the peel start end side toward the holding table 10 from above. Therefore, as the peel start end S1 is formed, the pressure plate 13 can be positioned on the outer periphery of the wafer W to press the outer periphery of the wafer W, thereby preventing the wafer W from lifting up. Furthermore, the protective sheet S can be peeled off from the wafer W while the outer periphery of the wafer W is being pressed down by the pressure plate 13. This prevents the wafer W from being pulled up by the protective sheet S, even if the wafer W is thinned. Furthermore, damage to the wafer W and chipping of the outer edge can be prevented.

[0046] The peeling start end forming unit 20 has a support part 25, a pair of needles 21, 21 (also referred to as pointed ends 21, 21), and the like.

[0047] The needles 21, 21 have sharp tips, and can be inserted (engaged) by piercing the side end surface S2 of the sheet S. In this embodiment, the needles 21 are arranged in pairs at a distance from each other in a width direction (hereinafter simply referred to as the width direction) that intersects with the peeling direction of the protective sheet S. The needles 21, 21 are arranged so that their tips face the side end surface S2 on the peel start side in a horizontal direction. That is, the needles 21, 21 are arranged parallel to the attachment surface of the protective sheet S. Therefore, the pair of needles 21, 21 can engage the protective sheet S from both sides in the width direction of the protective sheet S. That is, the protective sheet S and the needles 21, 21 can be engaged in a balanced manner from both sides in the width direction of the protective sheet S. This prevents the engagement from being released. Furthermore, because the needles 21, 21 can be pierced and engaged with the side end surface S2 of the protective sheet S in a horizontal direction, damage to the wafer W can be prevented.

[0048] The needles 21, 21 have their rear ends supported by a support portion 25 (described later). The needles 21, 21 are capable of rotation about an axis 26 of the support portion 25 and vertical and horizontal movement relative to the holding table 10. Therefore, with the needles 21, 21 positioned so as to face the side end surface S2 in the horizontal direction, the holding table 10 can be moved horizontally toward the tips of the needles 21, 21 to engage with the side end surface S2 on the peel start side. Furthermore, with the needles 21, 21 engaged with the side end surface S2, the needles 21, 21 can be rotated upward to lift the protective sheet S upward and form the peel start end S1. This prevents the needles 21, 21 from penetrating the protective sheet S in a direction intersecting the adhesive surface and contacting the wafer W. This prevents damage to the wafer W. Furthermore, since the pair of needles 21, 21 engages the protection sheet S with the needles 21, 21 in a well-balanced manner, the peel start end S1 can be formed accurately and reliably.

[0049] Furthermore, the needles 21, 21 are curved upward toward the rear end. The needles 21, 21 are formed, for example, from a conductive metal. Therefore, the needles 21, 21 can be positioned in the height direction by contacting the lowest part of the needles 21, 21 with the upper surface of the table frame 12 to establish electrical connection. Details of the positioning of the needles 21, 21 in the height direction will be described later. Note that at least one needle 21 is sufficient, but when peeling off a wide protective sheet S as in this embodiment, it is preferable to provide multiple needles 21. In such a case, it is desirable to arrange the needles evenly along the width direction of the protective sheet S. This allows the load applied during peeling to be evenly distributed, and the load applied to the wafer W to be evenly distributed.

[0050] The support portion 25 supports the rear ends of the needles 21, 21. Specifically, the support portion 25 supports the needles 21, 21 in an inclined position along the direction in which the rear ends of the needles 21, 21 face. Therefore, the support portion 25 can be positioned at a distance from the holding table 10. This prevents the support portion 25 from interfering with the holding table 10. The support portion 25 is rotatably supported by a support frame (not shown) via a shaft 26. The support portion 25 is capable of rotation about the shaft 26 and vertical movement and horizontal movement along the peeling direction, driven by a suitable driving source (not shown), such as a motor. Therefore, the needles 21, 21 are capable of rotation about the shaft 26 and vertical movement and horizontal movement along the peeling direction. The support portion 25 also has a built-in heater 27 (also referred to as a heating portion 27) that can heat the needles 21, 21. This heats and softens the adhesive of the protective sheet S, reducing resistance during peeling. This facilitates peeling of the protective sheet S, which will be described later. The heating temperature of the heater 27 can be changed as appropriate depending on the composition of the protective sheet S and the adhesive.

[0051] The first sheet holding unit 30 is composed of a pair of chucks that can be opened and closed by an appropriate drive source (not shown), and is able to clamp the peel-starting end S1 of the protective sheet S. Furthermore, the first sheet holding unit 30 has unevenness formed by knurling or the like on the surface that comes into contact with the protective sheet S. This allows the protective sheet S to be securely clamped, and prevents the protective sheet S from falling off the first sheet holding unit 30.

[0052] The first sheet holding unit 30 is disposed so as to be positioned approximately in the center between the needles 21, 21. Therefore, it can clamp the peeling start end S1 without interfering with the needles 21, 21. This allows the peeling start end S1 formed by the needles 21, 21 to be held more reliably and quickly. The first sheet holding unit 30 is also designed to be swiveled in an upright direction, as shown in FIG. 2. Therefore, as will be described in detail later, the first sheet holding unit 30 can be swiveled in an upright direction while clamping the peeling start end S1, as shown in FIGS. 5(d) and 10. This widens the gap between the wafer W and the protective sheet S at the peeling start end S1.

[0053] As shown in FIG. 1, the second sheet holding units 40 are disposed on both sides of the first sheet holding unit 30 in the width direction intersecting the peeling direction. As shown in FIGS. 1 and 2, each of the second sheet holding units 40 is composed of a pair of chucks extending along the width direction of the protective sheet S. The pair of chucks in the second sheet holding unit 40 are configured to be openable and closable by an appropriate drive source (not shown), and are able to clamp the raised peel start end S1. In addition, the second sheet holding unit 40 has an uneven surface formed by knurling or the like on the surface that comes into contact with the protective sheet S. This allows the protective sheet S to be securely clamped, preventing the protective sheet S from falling off the second sheet holding unit 40.

[0054] Furthermore, the pair of second sheet holding units 40, 40 are supported by an appropriate support frame (not shown), and as the holding table 10 moves horizontally in the peeling direction, the sandwiched protective sheet S can be pulled toward the other end in the peeling direction. This allows the protective sheet S to be peeled off from the surface of the wafer W. In this manner, in this embodiment, both widthwise sides of the formed peeling start end S1 can be sandwiched between the pair of second sheet holding units 40, 40 along the widthwise direction. Furthermore, while the protective sheet S is sandwiched between the pair of second sheet holding units 40, 40, the protective sheet S can be pulled and peeled off. Therefore, even when peeling off a wide protective sheet S, the protective sheet S can be prevented from being squeezed toward the center when pulled. This reduces the load applied to the wafer W and prevents damage to the wafer W. Furthermore, because the protective sheet S is securely held by the second sheet holding units 40, 40, it is possible to prevent the protective sheet S from coming off the second sheet holding units 40, 40 during peeling, thereby preventing peeling failures.

[0055] As shown in FIG. 1, the measurement unit 50 is provided near and above the holding table 10. For example, an in-process gauge is used as the measurement unit 50. Hereinafter, the measurement unit 50 may also be referred to as the in-process gauge 50. As shown in FIG. 3, the measurement unit 50 can be positioned above the outer edge of the wafer W held on the holding table 10 by an appropriate drive source (not shown). The in-process gauge 50 can measure the distance d1 between the in-process gauge 50 and the holding surface (top surface) of the holding table 10, for example, by optical means. This allows the height of the holding surface of the holding table 10 to be obtained. The in-process gauge 50 can also measure the distance d2 between the in-process gauge 50 and the top surface of the protective sheet S. The thickness d3 of the wafer W can be determined directly by measurement, or a known thickness d3 can be used. The thickness d4 of the protective sheet S can be calculated by subtracting the distance d2 and the thickness d3 from the distance d1. The thickness d4 of the protective sheet S can be calculated, for example, by a calculation device of the control unit 60, which will be described later.

[0056] The control unit 60 includes, for example, a control computer and can perform various controls of the sheet peeling device 1, such as the holding table 10, the peel start end forming unit 20, the first sheet holding unit 30, and the second sheet holding unit 40. The control unit 60 can control the heightwise position of the needles 21, 21 based on information about the thickness d4 of the protective sheet S, the thickness d3 of the wafer W, and the height of the holding surface of the holding table 10. This can prevent contact between the wafer W and the needles 21, 21, and prevent damage to the wafer W. Furthermore, even if the wafer W is thinned (for example, to a thickness of 100 μm), the needles 21, 21 can be reliably engaged with the protective sheet S. This allows the protective sheet S to be reliably peeled from the wafer W.

[0057] The above is an embodiment of the sheet peeling device 1 according to the present invention. In this embodiment, the sheet holding unit is separated into the first sheet holding unit 30 and the second sheet holding unit 40. However, it is also possible to eliminate either the first sheet holding unit 30 or the second sheet holding unit 40. In such a case, the protective sheet S is peeled off by horizontally moving the holding table 10 in the peeling direction while the peeling start end S1 is held between the first sheet holding unit 30 or the second sheet holding unit 40. Next, a sheet peeling method for peeling the protective sheet S from the wafer W using the sheet peeling device 1 will be described below with reference to FIGS. 4 to 11. It should be noted that irrelevant components are omitted in FIGS. 4 to 11 for simplicity.

[0058] 4(a) and 7, the wafer W is transferred onto the holding table 10 by a robot hand (not shown) or the like with the protective sheet S facing upward. The wafer W transferred onto the holding table 10 is placed on the holding table 10 in a positioned state. Then, an adsorption force is generated in the adsorption portion 11, thereby holding the wafer W (plate-like member W) on the holding table 10 (plate-like member holding step).

[0059] Next, as described above, the in-process gauge 50 measures the distance d1 from the holding surface of the holding table 10, the distance d2 from the top surface of the protective sheet S, and the thickness d3 of the wafer W, and based on these, the height of the holding table 10, the height of the holding surface of the protective sheet S, the thickness d4 of the protective sheet S, and the height of the protective sheet S are determined (measurement process).

[0060] Next, based on the measurement results from the measurement process, the needles 21, 21 are positioned relative to the side end surface S2 (positioning process). In the positioning process, first, the lowermost parts of the needles 21, 21, which serve as the reference position, are brought into contact with the upper surface of the table frame 12 to establish electrical continuity, thereby acquiring the heightwise positions of the needles 21, 21. Next, based on the reference positions of the needles 21, 21 and the position of the side end surface S2 in the heightwise direction, position control is performed so that the needles 21, 21 face horizontally relative to the side end surface S2 on the peel start side. Note that the reference positions of the needles 21, 21 may be determined by means other than electrical continuity with the table frame 12.

[0061] Next, the suction portion 11 is heated by the heater 15, and the needles 21, 21 are heated by the heater 27 (heating step). This softens the adhesive of the protective sheet S, reducing resistance during peeling. This allows the protective sheet S to be easily peeled off, and prevents damage to the plate-like member.

[0062] 4(a) and 7, the holding table 10 moves horizontally toward the needles 21, 21 (points 21, 21), causing the needles 21, 21 to insert into and engage with the side end surface S2 of the protective sheet S on the peel start side (point engaging step). In this way, in the point engaging step, the needles 21, 21 can be engaged horizontally with the side end surface S2 of the protective sheet S on the peel start side. This prevents the needles 21, 21 from penetrating through in a direction intersecting the sheet surface and coming into contact with the wafer W. This prevents the wafer W from being damaged.

[0063] 4(b) and 8, the holding table 10 is further advanced toward the needles 21, 21 while the needles 21, 21 are slightly rotated upward to form a peeling start edge S1 (peeling start edge forming step). After the peeling start edge S1 is formed in the peeling start edge forming step, the outer periphery of the wafer W on the peeling start edge side is pressed from above toward the holding table 10 by the pressing plate 13 (plate-like member pressing step). This prevents the wafer W from being pulled by the protective sheet S and lifting up, even if the wafer W has been thinned. This also prevents the wafer W from being damaged or its outer edge from chipping.

[0064] 5(c) and 9, the peeling start end S1 formed by the first sheet holding unit 30 is clamped and held at the middle of the needles 21, 21 (first sheet holding step). This ensures that the peeling start end S1 is formed.

[0065] Next, as shown in FIG. 5(d) and FIG. 10, the first sheet holding unit 30 is rotated so that the first sheet holding unit 30 is in an upright position while the peeling start end S1 is clamped by the first sheet holding unit 30. That is, the first sheet holding unit 30 pulls the peeling start end S1 upward, widening the gap between the wafer W and the protective sheet S (sheet lifting process). This ensures that the sheet margin to be clamped by the second sheet holding unit 40 is formed. This prevents peeling errors. The amount by which the peeling start end S1 is lifted can be changed as appropriate depending on the position at which the second sheet holding units 40, 40 clamp the sheet. This makes it possible to control the holding width of the sheet S.

[0066] Next, as shown in FIGS. 6(e) and 11, both widthwise sides of the raised peel start end S1 are clamped by the pair of second sheet holding units 40, 40, and the clamping of the peel start end S1 by the first sheet holding unit 30 is released (second sheet holding step). In this way, in the second sheet holding step, both widthwise sides of the raised peel start end S1 can be clamped by the pair of second sheet holding units 40, 40 formed along the width direction. Therefore, in the subsequent sheet peeling step, the protective sheet S is prevented from being squeezed toward the center when pulled. This reduces the load applied to the wafer W and prevents damage to the wafer W. Furthermore, because the protective sheet S is reliably held by the second sheet holding unit 40, 40, peeling failure caused by the protective sheet S coming off the second sheet holding units 40, 40 during peeling can be prevented.

[0067] Furthermore, since the first sheet holding unit 30 releases its grip on the peel start end S1 while the second sheet holding units 40, 40 hold both widthwise sides of the peel start end S1, the protective sheet S can be transferred from the first sheet holding unit 30 to the second sheet holding units 40, 40 while avoiding interference between the first sheet holding unit 30 and the second sheet holding units 40, 40. Note that the grip on the peel start end S1 by the first sheet holding unit 30 can be released as needed, and it is also possible to peel the protective sheet S together with the first sheet holding unit 30 and the second sheet holding units 40, 40 without releasing the grip.

[0068] 6(f), the holding table 10 moves back along the peeling direction while the second sheet holding units 40, 40 hold both sides of the peeling start end S1 along the width direction. That is, the second sheet holding units 40, 40 are moved relative to the holding table 10 toward the other end in the peeling direction, thereby peeling the protective sheet S from the wafer W (sheet peeling step). The peeled protective sheet S is discarded in an appropriate disposal box (not shown).

[0069] The above is a detailed description of each step of the sheet peeling method of the present invention. As described above, the sheet peeling method of the present invention allows for peeling of a sheet S, such as a protective sheet S, without using a peeling tape. This reduces the cost of the peeling tape. Furthermore, since the above-described sheet peeling method does not use a peeling tape, the peeling tape does not stick to the holding table 10. This eliminates the need for fluorocarbon treatment of the holding table 10. Furthermore, even if the sheet surface is contaminated, the sheet S can be reliably peeled. Therefore, the method is particularly suitable for peeling a protective sheet S used in the backgrinding process of a semiconductor wafer W. The sheet peeling device and sheet peeling method of the present invention provide a mechanism for peeling the side edge of the protective sheet S to form a peeling start end S1 and a mechanism for holding the protective sheet S for peeling, separately, thereby enabling more reliable peeling and enabling compatibility with various sheets.

[0070] The above is an embodiment of the sheet peeling device 1 and sheet peeling method of the present invention, but the sheet peeling device 1 and sheet peeling method of the present invention are not limited to the above-mentioned embodiment and can be modified in various ways.

[0071] In this embodiment, the sheet S is described as a protective sheet S used for a semiconductor wafer W, but various other sheets can be used in addition to the protective sheet S. Furthermore, the sheet S is not limited to a circular sheet, and various other shapes can be used. For example, the sheet S may be rectangular. Furthermore, in this embodiment, the sheet S is pulled and peeled off by the second sheet holding unit 40, but the second sheet holding unit 40 may be omitted, and the sheet S may be peeled off by the first sheet holding unit 30.

[0072] In this embodiment, the sheet S is peeled off by moving the holding table 10 horizontally in the peeling direction, but it is sufficient that the tip 21, the first sheet holding portion 30, and the second sheet holding portion 40 are movable horizontally in the peeling direction relative to the holding table 10. That is, the tip 21, the first sheet holding portion 30, and the second sheet holding portion 40 may move horizontally in the peeling direction. Also, in this embodiment, the tip 21, the first sheet holding portion 30, and the second sheet holding portion 40 are arranged to be movable up and down relative to the holding table 10, but it is also possible for the holding table 10 to move up and down. That is, it is sufficient that the tip 21, the first sheet holding portion 30, and the second sheet holding portion 40 are movable up and down relative to the holding table 10.

[0073] Furthermore, in this embodiment, a needle is used as the pointed end 21, but the pointed end 21 is not limited to a needle and various other objects such as a scraper or blade can be used. The shape and size of the pointed end 21 can be various shapes depending on the thickness of the sheet S to be peeled. Note that when the thickness of the sheet S is thin, it is desirable to use a needle or the like with a small tip area.

[0074] In addition, in this embodiment, a pair of pointed ends 21, 21 are provided spaced apart in the width direction of the sheet S, but a single pointed end 21 or two or more pointed ends 21 can be used in accordance with the width and shape of the sheet S. Furthermore, when multiple pointed ends 21 are provided, the widthwise spacing can be changed as appropriate in accordance with the width and shape of the sheet S.

[0075] Although the present embodiment illustrates a single first sheet holding portion 30, multiple first sheet holding portions 30 may be provided. Furthermore, in the present embodiment, the second sheet holding portions 40 are provided on both sides of the first sheet holding portion 30 along the width direction of the sheet S. However, a pair of second sheet holding portions 40, 40 may be integrated. In such cases, it is desirable to provide the second sheet holding portions 40 so as not to interfere with the first sheet holding portion 30. The second sheet holding portion 40 may be provided in various numbers, such as a single portion or a portion formed of two or more separate portions. The width of the second sheet holding portion 40 can be appropriately adjusted to suit the sheet S. The clamping width of the sheet S clamped by the second sheet holding portions 40, 40 can be appropriately adjusted by the amount of lifting of the peel start end S1. Furthermore, in the present embodiment, the sheet clamping surfaces of the first sheet holding portion 30 and the second sheet holding portion 40 are knurled to form irregularities. However, various means other than knurling can be used to improve frictional force. Furthermore, if the sheet S can be reliably held, it is possible to dispense with knurling or the like.

[0076] In this embodiment, an in-process gauge is provided in the measuring unit 50, but various measuring devices can be provided instead of the in-process gauge. Also, if the thickness of the sheet S and the thickness of the plate-like member W are constant or if the thickness of the sheet S is thick, the measuring unit 50 may not be provided.

[0077] Furthermore, in this embodiment, a presser plate 13 is provided to press the plate-shaped member W toward the holding table, but if there is no risk of the plate-shaped member W being lifted up, the presser plate 13 can be eliminated. The shape and size of the presser plate 13 can be changed as appropriate to match the shape of the plate-shaped member W. Furthermore, in this embodiment, heating units 15, 27 are provided to heat both the holding table 10 and the pointed end 21, but the heating units 15, 27 may be provided as appropriate to match the composition of the sheet S to be peeled, and it is also possible to eliminate either or both of the heating units 15, 27.

[0078] The above are embodiments and variations of the sheet peeling device and sheet peeling method according to the present invention, but the present invention is not limited to the examples in the above-mentioned embodiments and variations, and it will be easily understood by those skilled in the art that other embodiments are possible based on the teachings and spirit of the present invention within the scope of the claims. [Industrial Applicability]

[0079] The sheet peeling device and sheet peeling method of the present invention can be used to peel off various sheets, such as pressure-sensitive adhesive sheets, attached to various plate-like members.Furthermore, the sheet peeling device and sheet peeling method of the present invention can be preferably used to peel off various adhesive sheets, such as protective sheets attached to semiconductor wafers. [Explanation of symbols]

[0080] S: Sheet (protective sheet) S1: Peeling start point S2: Side end surface W: Plate-shaped member (semiconductor wafer) 1: Sheet peeling device 10: Holding table 13: Presser plate 15: Heater (heating part) 20: Peeling start end forming unit 21: Needle (tip) 27: Heater (heating part) 30: First sheet holding portion 40: Second sheet holding portion 50: In-process gauge (measuring part) 60: Control section

Claims

1. A sheet peeling device that peels off a sheet attached to a plate-like member from one end side to the other end side, a holding table that holds the plate-like member so that the sheet faces upward; At least one pointed portion provided so as to face a side end surface of the sheet at a peel start side in a horizontal direction; a sheet holding portion capable of holding one end of the sheet on the peel start side, the pointed end can be engaged with the side end surface from a horizontal direction by horizontal movement relative to the holding table, and can hook the sheet to form a peeling start end by moving the pointed end relative to the holding table upward while engaged with the side end surface, the sheet holding portion has a first sheet holding portion and a second sheet holding portion provided along a width direction intersecting with a peeling direction via the first sheet holding portion, the first sheet holding portion clamps the peeling start end and, by moving upward relative to the holding table, is capable of lifting the peeling start end upward from the upper surface of the plate-like member, A sheet peeling device characterized in that the pair of second sheet holding portions clamp both widthwise sides of the raised peeling starting end along the width direction, and move relative to the holding table toward the other end in the peeling direction, thereby peeling the sheet from the plate-shaped member.

2. a pair of the pointed ends are arranged at an interval in a width direction intersecting with a peeling direction of the sheet, 2. The sheet peeling device according to claim 1, wherein the peeling start end is formed by engaging each of the pair of pointed ends with the side end surface and moving the pointed ends upward relative to the holding table.

3. 3. The sheet peeling device according to claim 1, wherein the first sheet holding portion is disposed between the pair of pointed ends.

4. a measuring unit capable of measuring the height of the holding surface of the holding table and the thickness of each of the plate-like member and the sheet; 4. The sheet peeling device according to claim 1, further comprising: a control unit that controls the height of the pointed portion based on information measured by the measurement unit.

5. a pressing plate that presses an outer periphery of the plate-shaped member on the peeling start end side toward the holding table from above, The sheet peeling device according to any one of claims 1 to 4, characterized in that, as the peeling starting end is formed, the sheet is peeled off from the plate-like member while the outer periphery is pressed by the pressing plate.

6. 6. The sheet peeling device according to claim 1, further comprising a heating unit for heating either or both of the holding table and the pointed end.

7. 7. The sheet peeling device according to claim 1, wherein the plate-like member is a semiconductor wafer, and the sheet is a protective sheet for back grinding.

8. A sheet peeling method for peeling a sheet attached to a plate-like member from one end side to the other end side, a plate-like member holding step of holding the plate-like member on a holding table so that the sheet faces upward; a pointed end engaging step of engaging at least one pointed end with a side end surface of the sheet on a peel start side from a horizontal direction; a peeling start edge forming step of lifting the sheet upward by moving the pointed end upward relative to the holding table, and then a first sheet holding step of clamping the peel-starting end portion by a first sheet holding portion constituting a sheet holding unit; a sheet raising step of widening a gap between the plate-like member and the sheet by pulling the peel-starting end upward while the peel-starting end is clamped by the first sheet holding portion; a second sheet holding step of clamping both widthwise sides of the raised peeling starting end by a pair of second sheet holding parts that constitute the sheet holding part and are formed along the widthwise direction, and releasing the clamping of the peeling starting end by the first sheet holding parts; a sheet peeling step of relatively moving the second sheet holding unit toward the other end in the peeling direction relative to the holding table while the second sheet holding unit holds both sides of the peeling start end along the width direction of the sheet, thereby peeling the sheet from the plate-like member; and peeling the sheet from the plate-like member by sequentially performing the steps above.

9. a measuring step of measuring the height of the holding surface of the holding table and the thicknesses of the plate-like member and the sheet by a measuring unit prior to the tip engaging step; 9. The sheet peeling method according to claim 8, further comprising: a positioning step of positioning the pointed end portion relative to the side end surface based on a measurement result by the measuring unit.

10. 10. A sheet peeling method as described in claim 8 or 9, characterized in that in the peeling starting end forming process, a plate-like member pressing process is carried out in which, after the peeling starting end is formed, the outer periphery of the plate-like member on the peeling starting end side is pressed from above toward the holding table by a pressing plate.

11. 11. The sheet peeling method according to claim 8, wherein a heating step is performed prior to the tip engaging step, in which either or both of the holding table and the tip are heated.

12. 12. The sheet peeling method according to claim 8, wherein the plate-like member is a semiconductor wafer, and the sheet is a protective sheet for back grinding.

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