Sheet peeling method and sheet peeling apparatus

Abstract

The present invention provides a sheet peeling method and a sheet peeling apparatus that can reduce the cost of release sheets by reusing them. [Solution] A sheet peeling method comprising: a first holding step S11 of holding a wafer W so that a protective sheet 7 is exposed; a first fixing step S12 of fixing one end Sa side of a release sheet S to the outer peripheral region of the protective sheet 7 on the surface Wa of the wafer W; a peeling step S15 of peeling the protective sheet 7 from the surface Wa of the wafer W; a removal step S16 of removing the release sheet S from the protective sheet 7 to which the release sheet S is fixed; a second holding step S21 of holding another wafer W so that another protective sheet 7 is exposed; and a second fixing step S22 after the second holding step S21 of fixing the release sheet S removed in the removal step S16 to another protective sheet 7 fixed to the surface Wa of the other wafer W.

Description

Technical Field

[0001] The present invention relates to a sheet peeling method and a sheet peeling device for peeling a sheet fixed to a fixed surface of an adherend.

Background Art

[0002] Semiconductor wafers and the like are ground by a grinding device to form a predetermined thickness, and then divided by a cutting device or the like into individual devices and the like, and are used in various electronic devices and the like. Specifically, in a grinding device, after holding one surface of a wafer on which a plurality of devices such as ICs and LSIs are formed in a region partitioned by a dividing line by a holding table, the other surface of the wafer is ground with a rotating grinding wheel. A protective sheet formed of a resin such as vinyl chloride is previously adhered to one surface of this wafer.

[0003] After grinding the other surface of the wafer, the other surface of the wafer is held by a holding table or the like, and the protective sheet is peeled from one surface of the wafer. Then, while detecting the dividing line on one surface of the wafer on which the device is formed by a cutting device, cutting is performed along the dividing line, and the wafer is divided into individual chips.

[0004] In Patent Document 1, a method is disclosed in which a dicing tape is adhered to the other surface of a wafer to which a protective sheet is adhered on one surface and a ring frame, and then the protective sheet is peeled from one surface of the wafer.

[0005] In peeling the protective sheet, a strip-shaped peeling sheet is fixed to the outer peripheral portion of the protective sheet, cut into a strip shape, and the gripping portion grips the peeled sheet while bending the protective sheet above the wafer and moving the gripping portion parallel to the upper surface of the wafer.

[0006] The protective sheet, once detached from the wafer, is held by the gripping unit via the release sheet. By moving the gripping unit to the waste bin and releasing the grip on the release sheet, the protective sheet and the release sheet together are discarded. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2017-191810 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, since each release sheet is discarded, there is a problem in that the cost of the release sheets is high. Therefore, there is a challenge to reduce the cost of release sheets in the sheet peeling process, which involves peeling the sheet that is adhered to the surface of the object to be bonded.

[0009] This invention provides a sheet peeling method and a sheet peeling apparatus that can reduce the cost of release sheets by reusing them. [Means for solving the problem]

[0010] The present invention A method for peeling off a sheet that is attached to the surface of an object to be attached, A first holding step involves holding the object to be fixed so that the sheet fixed to the surface to be fixed is exposed, After the first holding step, a first fixing step is performed in which one end of the release sheet is fixed to the outer peripheral region of the sheet on the surface of the object to be fixed, After the first fixing step, a peeling step is performed to peel the sheet from the surface to be fixed, After the peeling step, a removal step is performed to remove the peeling sheet from the sheet to which the peeling sheet has been fixed, A second holding step involves holding the other object to be fixed so that other sheets fixed to the surface of the other object to be fixed are exposed, The method further includes a second fixing step, in which, after the second holding step, the release sheet removed in the removal step is fixed to the other sheet that is fixed to the surface of the other object to be fixed.

[0011] Furthermore, the present invention is A sheet peeling device for peeling off a sheet that is fixed to the surface of an object to be fixed, A holding unit that holds the object to be fixed such that the sheet fixed to the surface to be fixed is exposed, A release sheet fixing unit that fixes one end of the release sheet to the outer peripheral region of the sheet to be fixed surface held by the holding unit, A gripping portion for gripping the other end of the release sheet, A moving unit that moves the gripping portion and the holding unit relative to each other, The system includes a removal unit that, after peeling the sheet from the object to which it has been attached, removes the release sheet from the sheet to which it has been attached. [Effects of the Invention]

[0012] According to the present invention, the cost of release sheets can be reduced by reusing them. [Brief explanation of the drawing]

[0013] [Figure 1] (A) is a diagram illustrating the process of attaching a protective sheet 7 to the surface Wa of wafer W, and (B) is a diagram showing wafer W with the protective sheet 7 attached. [Figure 2] This is a flowchart of one embodiment of the sheet peeling method of the present invention. [Figure 3] This is a cross-sectional view of the area around the holding table 21 to illustrate the first holding step S11. [Figure 4] This is a cross-sectional view of the area around the holding table 21 to illustrate the heating step of the first fixing step S12. [Figure 5] It is a cross-sectional view around the holding table 21 for explaining the cutting step of the first fixing step S12. [Figure 6] It is a cross-sectional view around the holding table 21 for explaining the wafer W to which the peeling sheet S is fixed after the first fixing step S12. [Figure 7] It is a plan view around the holding table 21 for explaining the wafer W to which the peeling sheet S is fixed after the first fixing step S12. [Figure 8] It is a cross-sectional view around the holding table 21 for explaining the peeling step S15. [Figure 9] It is a cross-sectional view around the holding table 21 showing the wafer W and the protective sheet 7 after the peeling step S15. [Figure 10] It is a diagram showing the external force applying mechanism 70 constituting the removing mechanism 63. [Figure 11] It is a diagram for explaining the removing step S16 by the external force applying mechanism 70, where (A) shows the state just before removal, (B) shows the state during removal, and (C) shows the state just after removal. [Figure 12] It is a diagram showing the rotating mechanism 80 constituting the removing mechanism 63. [Figure 13] It is a diagram for explaining the removing step S16 by the rotating mechanism 80, where (A) shows the state just before removal, (B) shows the state during removal, and (C) shows the state just after removal. [Figure 14] It is a plan view around the holding table 21 for explaining the second holding step S21. [Figure 15] It is a cross-sectional view around the holding table 21 for explaining the heating step of the second fixing step S22. [Figure 16] It is a cross-sectional view around the holding table 21 for explaining the wafer W to which the peeling sheet S is fixed after the second fixing step S22. [Figure 17] It is a plan view around the holding table 21 for explaining the wafer W to which the peeling sheet S is fixed after the second fixing step S22. [Modes for carrying out the invention]

[0014] Hereinafter, an embodiment of the sheet peeling method and sheet peeling apparatus of the present invention will be described with reference to the drawings.

[0015] First, the sheet peeling method and the wafer W that can be used in the sheet peeling apparatus will be explained with reference to Figures 1(A) and (B). The wafer W is, for example, a roughly disc-shaped substrate made of materials such as Si (silicon), SiC (silicon carbide), GaN (gallium nitride), GaAs (gallium arsenide), or other semiconductor materials. However, the wafer W is not limited to these.

[0016] The surface Wa of wafer W is divided into multiple intersecting division lines 3, as shown in Figure 1(A). Devices 5, such as ICs and LSIs, are formed in each region of the wafer W surface Wa divided by the division lines 3. By dividing wafer W along the division lines 3, individual device chips, each containing a device, can be manufactured. Dividing wafer W is performed using processing equipment such as a cutting machine or a laser processing machine.

[0017] In the semiconductor manufacturing process before wafer W is split, a circular protective sheet 7 is sometimes attached to the surface Wa of the wafer W. The protective sheet 7 is, for example, a circular film having an outer diameter equivalent to that of the wafer W, and comprises an exposed surface 7a made of a substrate and an adhesive surface 7b made of an adhesive glue layer. The adhesive glue layer of the protective sheet 7 is attached (fixed) to the surface Wa of the wafer W.

[0018] The sheet peeling method of this embodiment is a method of peeling off the protective sheet 7 that is attached to the surface Wa of the wafer W before it is divided into device chips from the surface Wa of the wafer W.

[0019] First, the sheet peeling device 10 of this embodiment will be described. The sheet peeling apparatus 10 is a device for peeling off a protective sheet 7 attached to the surface Wa of a wafer W using a release sheet S. As shown in Figure 3, the sheet peeling apparatus 10 comprises a holding unit 20 for holding the wafer W, a release sheet fixing unit 30 for fixing one end Sa side of the release sheet S to the outer peripheral region of the protective sheet 7 of the wafer W held by the holding unit 20, a gripping part 40 for gripping the other end Sb side of the release sheet S, a moving unit 50 for relatively moving the gripping part 40 and the holding unit 20, and a removal unit 60 (see Figures 10 and 12) for removing the release sheet S from the protective sheet 7 after the protective sheet 7 has been peeled off the wafer W.

[0020] The holding unit 20 includes a disc-shaped holding table 21. The holding table 21 has a holding surface 23 for holding the wafer W, formed from porous ceramic or the like. The holding table 21 is also connected to a vacuum suction source (not shown), and the wafer W is sucked and held by the vacuum suction source. The holding unit 20 holds the wafer W such that the protective sheet 7 attached to the surface Wa of the wafer W is exposed upwards.

[0021] The release sheet fixing unit 30 is for fixing the release sheet S to the protective sheet 7 of the surface Wa held by the holding unit 20, and comprises a release sheet supply unit 32, a heating unit 34, and a cutting unit 38.

[0022] The release sheet supply unit 32 includes a feed roll (not shown) on which a long length of release sheet S is wound, and a plurality of rollers 33 that form a path for the release sheet S fed from the feed roll. The release sheet S has, for example, a base layer made of resin, and an adhesive layer formed on one side of the base layer. The material of the base layer is, for example, polyethylene terephthalate, and the adhesive layer is made of, for example, a thermosetting resin such as epoxy resin. The release sheet S is, for example, a strip-shaped sheet with a width of 50 mm, and is a thermocompression sheet that adheres to the protective sheet 7 by heating. The release sheet S is transported so that the adhesive layer faces the wafer W and the base layer faces the heating unit 34.

[0023] The heating unit 34 includes a heater 35 for heating the release sheet S, a heat transfer unit 36 ​​for transferring heat from the heater 35 to the release sheet S, and a heat transfer control unit (not shown) configured to move the heat transfer unit 36 ​​vertically. The heating unit 34 is positioned above the path of the release sheet S, and the heat transfer control unit moves the heat transfer unit 36 ​​downward. The lower surface of the heat transfer unit 36 ​​extends in the width direction of the release sheet S. The shape of the lower surface of the heat transfer unit 36 ​​may be a straight line or an arc shape that follows the outer edge of the wafer W. The heating unit 34 heat-presses (fixes) the release sheet S to the protective sheet 7 by maintaining the release sheet S in contact with the protective sheet 7 at a predetermined temperature for a predetermined time using the heat transfer unit 36.

[0024] Referring also to Figure 7, the fixing portion H1 between the release sheet S and the protective sheet 7 is formed along the width direction of the release sheet S. The shape of the fixing portion H1 follows the shape of the lower surface of the heat transfer portion 36, and is a straight line or arc that is long in the width direction of the release sheet S. That is, the fixing portion H1 is long in the width direction of the release sheet S and short in the direction of extension of the release sheet S. Note that the heater 35 may be configured to be movable together with the heat transfer portion 36, or the heater 35 may be fixed and the heat transfer portion 36 may be configured to be movable.

[0025] The cutting section 38 includes a cutter 39 for cutting the release sheet S, which is fixed to the protective sheet 7, to a predetermined length, and a cutter control unit (not shown) that is configured to move the cutter 39 up and down. The cutter 39 is positioned above the path of the release sheet S and between the roller 33 and the heating section 34, and the cutter control unit moves the cutter 39 downward to cut the release sheet S. The cutter 39 may also be configured to move in the width direction of the release sheet S by the cutter control unit.

[0026] The release sheet S is fixed at one end to a feed roll (not shown) and gripped at the other end by a gripping section 40. The gripping section 40 has a pair of clamps that are opposite each other vertically, and the release sheet S is held between the pair of clamps.

[0027] The moving unit 50 moves the gripping portion 40 relative to the holding unit 20 in which the wafer W is held. In this embodiment, the moving unit 50 is configured so that the gripping portion 40 is movable relative to the holding unit 20. When peeling the protective sheet 7 from the surface Wa of the wafer W, the moving unit 50 moves the gripping portion 40 toward the center of the protective sheet 7 in the direction in which the release sheet S extends.

[0028] Here, it is preferable that the path of the release sheet S extends radially from the center of the holding table 21. As a result, the direction of extension of the release sheet S lies in the direction connecting the center of the protective sheet 7 and the gripping portion 40, and from the perspective of the gripping portion 40, the direction of extension of the release sheet S is toward the center of the protective sheet 7. As mentioned above, the adhesive portion H1 formed on the release sheet S is long in the width direction of the release sheet S and short in the extension direction of the release sheet S. Therefore, the adhesive force is relatively strong against the force in the extension direction of the release sheet S and relatively weak against the force in the width direction of the release sheet S. Accordingly, by moving the gripping portion 40 that grips the other end Sb of the release sheet S relative to the protective sheet 7 via the center of the protective sheet 7 along the extension direction of the release sheet S using the moving unit 50, the protective sheet 7 to which one end Sa of the release sheet S is adhered can be peeled from the wafer W.

[0029] The removal unit 60 removes the release sheet S from the protective sheet 7 that has been peeled off from the wafer W. As shown in Figures 10 and 12, the removal unit 60 includes a holding plate 61 for holding the protective sheet 7, a fixing part 62 for fixing the protective sheet 7 held on the holding plate 61, and a removal mechanism 63.

[0030] Here, the retaining plate 61 contacts the exposed surface 7a of the protective sheet 7 and holds the protective sheet 7 so that the adhesive surface 7b is exposed upwards. The retaining plate 61 is also provided with a notch 65, and holds the protective sheet 7 so that the release sheet S is exposed downwards through the notch 65. Note that the vertical direction may be reversed.

[0031] The fixing part 62 contacts the adhesive surface 7b of the protective sheet 7 and fixes the protective sheet 7 to the holding plate 61. The removal mechanism 63 may be configured to apply an external force to the protective sheet 7 or the release sheet S in a direction perpendicular to the extending direction of the release sheet S (hereinafter also referred to as the width direction of the release sheet S) by the external force application mechanism 70 shown in Figure 10 so that the protective sheet 7 and the release sheet S are separated, or it may be configured to rotate the gripping part 40 along the width direction of the release sheet S by the rotation mechanism 80 shown in Figure 12 so that the protective sheet 7 and the release sheet S are separated.

[0032] As shown in Figure 10, the external force application mechanism 70 includes a movable body 72 and a drive unit 73 that moves the movable body 72 along the width direction of the release sheet S. The movable body 72 has an inclined surface 71 on which the surface that contacts the release sheet S moves away from the protective sheet 7 as it moves away from the release sheet S along the width direction of the release sheet S. In the external force application mechanism 70 configured in this way, as shown in Figure 11(A), the movable body 72 is moved along the width direction of the release sheet S with respect to the protective sheet 7 which is fixed to the holding plate 61 by a fixing unit 62. Then, as shown in Figure 11(B), as the movable body 72 moves in the width direction of the release sheet S, an external force is applied to the release sheet S from the inclined surface 71 in a direction perpendicular to the inclined surface 71. This external force is decomposed into a force that presses the release sheet S in the width direction of the release sheet S and a force that acts downward in a direction away from the protective sheet 7. Therefore, as the moving body 72 moves in the width direction of the release sheet S, the release sheet S that is in contact with the inclined surface 71 is guided downward and separated from the protective sheet 7, and as shown in Figure 11(C), the release sheet S peels off from the protective sheet 7.

[0033] As shown in Figure 12, the rotating mechanism 80 has a drive unit 83 that rotates the gripping part 40 along the width direction of the release sheet S so that the protective sheet 7 and the release sheet S are separated. With the rotating mechanism 80 configured in this way, from the state shown in Figure 13(A), by rotating the release sheet S with one side Sd in the width direction of the release sheet S towards the rotation axis and the opposite side Sc moving in the direction away from the release sheet S (downward), as shown in Figure 13(B), the release sheet S gradually separates from the protective sheet 7, and as shown in Figure 13(C), the release sheet S peels off from the protective sheet 7.

[0034] Next, a sheet peeling method using the sheet peeling apparatus 10 configured as described above will be explained. As shown in Figure 2, the sheet peeling method of this embodiment comprises a first holding step S11 for holding a wafer W, a first fixing step S12 (heating step S13, cutting step S14) for fixing a release sheet S to the protective sheet 7 of the wafer W, a peeling step S15 for peeling the protective sheet 7 from the wafer W, a removal step S16 for removing the release sheet S from the protective sheet 7, a second holding step S21 for holding another wafer W, a second fixing step S22 (heating step S23) for fixing the release sheet S removed in the removal step S16 to the protective sheet 7 of this other wafer W, a peeling step S25 for peeling the protective sheet 7 from this other wafer W, and a removal step S26 for removing the release sheet S from the protective sheet 7. Furthermore, the second holding step S21, the second fixing step S22 (heating step S23), the peeling step S25, and the removal step S26 can be repeated as long as the release sheet S can be reused.

[0035] In the first holding step S11, as shown in Figure 3, the wafer W is held on the holding table 21 such that the protective sheet 7 attached to the surface Wa of the wafer W is exposed upwards. At this time, the release sheet S is fed to the release sheet supply section 32 of the release sheet fixing unit 30, and the other end Sb of the release sheet S is gripped by the gripping section 40. As viewed from the gripping section 40, the extending direction of the release sheet S is toward the center of the holding table 21.

[0036] The first fixing step S12 includes a heating step S13 and a cutting step S14. In the heating step S13 of the first fixing step S12, as shown in Figure 4, the heat transfer part 36 of the heating part 34 moves downward, pressing the release sheet S against the protective sheet 7 on the surface Wa of the wafer W, and the release sheet S is heat-pressed to the protective sheet 7 by maintaining a predetermined temperature for a predetermined time while in contact with the protective sheet 7. For example, the release sheet S is heat-pressed to the protective sheet 7 by being maintained at 200°C for 3 seconds while in contact with the protective sheet 7.

[0037] In the cutting step S14 of the first fixing step S12, as shown in Figure 5, the heat transfer part 36 of the heating part 34 moves upward and the cutter 39 of the cutting part 38 moves downward to cut the release sheet S. For example, the release sheet S is cut to a length of 100 mm by the cutter 39.

[0038] After the first fixing step S12, as shown in Figure 6, the cutter 39 of the cutting section 38 moves upward. As a result of this first fixing step S12, as shown in Figure 7, one end Sa of the cut release sheet S is welded to the protective sheet 7, forming a fixed portion H1 in the outer peripheral region of the protective sheet 7. As a result, the release sheet S is fixed so that its extending direction is toward the center of the protective sheet 7, and one end Sa is fixed in an arc shape or straight line along the width direction of the release sheet S. The outer peripheral region of the protective sheet 7 is the region close to the outer edge of the wafer W, and is the region where the device 5 is not formed.

[0039] In the peeling step S15, as shown in Figure 8, the moving unit 50 moves the gripping portion 40, which holds the other end Sb of the peeling sheet S, in the direction of extension of the peeling sheet S toward the center of the holding table 21. As a result, the protective sheet 7 is peeled off from the surface Wa of the wafer W, as shown in Figure 9. At this time, the moving unit 50 may move in a direction horizontal to the holding surface 23 of the holding table 21, or it may move upward while moving horizontally. Note that the configuration of the moving unit 50 is not limited to the gripping portion 40 moving relative to the holding unit 20; the holding unit 20 may also move relative to the gripping portion 40 to peel off the protective sheet 7 from the surface Wa of the wafer W.

[0040] Next, in the removal step S16, with the gripping part 40 gripping the other end Sb of the release sheet S, the protective sheet 7 that has been peeled off from the surface Wa of the wafer W is placed on the holding plate 61 of the removal unit 60 and fixed with the fixing part 62. Then, the external force application mechanism 70 of Figure 10, which constitutes the removal mechanism 63, applies an external force by bringing the inclined surface 71 of the moving body 72 into contact with the release sheet S from the width direction so that the protective sheet 7 and the release sheet S are separated, as explained in Figures 11(A) to (C), thereby peeling the release sheet S from the protective sheet 7. Alternatively, instead of the external force application mechanism 70, the rotation mechanism 80 of Figure 12, which constitutes the removal mechanism 63, may be used to rotate the gripping part 40 so that the protective sheet 7 and the release sheet S are separated, as explained in Figures 13(A) to (C), thereby peeling the release sheet S from the protective sheet 7.

[0041] From the second holding step S21 onward, a different wafer W is used than the one used in the first holding step S11 to the cutting step S14. Naturally, the protective sheet 7 attached to this wafer W is different from the protective sheet 7 attached to the wafer W used in the first holding step S11 to the cutting step S14.

[0042] In the second holding step S21, as shown in Figure 14, the wafer W is held on the holding table 21 such that the protective sheet 7 attached to the surface Wa of the wafer W is exposed upwards.

[0043] In the second fixing step S22, the release sheet S removed in the removal step S16 is again placed on the protective sheet 7 of the wafer W held on the holding table 21, so that, as viewed from the gripping portion 40, the extending direction of the release sheet S is toward the center of the holding table 21.

[0044] At this time, the release sheet S is positioned so that the fixed portion H1 formed in the previous heating step S13 does not come directly below the heat transfer portion 36 of the heating portion 34, that is, so that the fixed portion H2 formed in the next heating step S23 is offset to a different position from the already formed fixed portion H1. Preferably, the offset direction is such that the newly formed fixed portion moves sequentially toward the center of the protective sheet 7.

[0045] Next, the release sheet S, positioned in this manner, is fixed to the protective sheet 7. The second fixing step S22 includes a heating step S23 but does not include a cutting step. In the heating step S23 of the second fixing step S22, as shown in Figure 15, the heat transfer part 36 of the heating part 34 moves downward, pressing the release sheet S against the protective sheet 7 on the surface Wa of the wafer W, and by maintaining the release sheet S in contact with the protective sheet 7 at a predetermined temperature for a predetermined time, the release sheet S is thermally pressed to the protective sheet 7. For example, the release sheet S is thermally pressed to the protective sheet 7 by being maintained at 200°C for 3 seconds while in contact with the protective sheet 7.

[0046] After the second fixing step S22, as shown in Figure 16, the heat transfer part 36 of the heating part 34 moves upward. As a result of this second fixing step S22, as shown in Figure 17, one end Sa of the cut release sheet S is welded to the protective sheet 7, forming a fixing part H2 in the outer peripheral region of the protective sheet 7, and the release sheet S is fixed to the protective sheet 7.

[0047] Here, since the fixing portion H2 is offset from the already formed fixing portion H1, it is possible to avoid the influence of the previously performed heating step on the next heating step. Specifically, by ensuring that the positions of the fixing portions do not overlap, it is possible to suppress the situation in which the adhesive strength decreases due to deterioration of the adhesive layer.

[0048] Furthermore, the temperature of the heater 35 may be controlled so that the heating step S23 of the second fixing step S22 is performed at a higher temperature than the heating step S13 of the first fixing step S12. By varying the temperature of the heater 35 so that the heat is performed at a higher temperature than the previous heat bonding that has already been performed, even if the fixing temperature of the adhesive changes due to the effect of heat propagated around the fixing part during the previously performed heat bonding, a decrease in adhesive strength can be suppressed.

[0049] In the peeling step S25, similar to the peeling step S15, as shown in Figure 8, the gripping portion 40 that holds the other end Sb of the peeling sheet S by the moving unit 50 is moved in the direction of extension of the peeling sheet S toward the center of the holding table 21. As a result, as shown in Figure 9, the protective sheet 7 is peeled off from the surface Wa of the wafer W.

[0050] Next, in the removal step S26, similar to the removal step S16, the protective sheet 7 peeled from the surface Wa of the wafer W is placed on the holding plate 61 of the removal unit 60 and fixed with the fixing part 62. Then, the external force application mechanism 70 of Figure 10, which constitutes the removal mechanism 63, applies an external force by bringing the inclined surface 71 of the moving body 72 into contact with the release sheet S from the width direction so that the protective sheet 7 and the release sheet S are separated, as explained in Figures 11(A) to (C), thereby peeling the release sheet S from the protective sheet 7. Alternatively, instead of the external force application mechanism 70, the rotation mechanism 80 of Figure 12, which constitutes the removal mechanism 63, may be used to rotate the gripping part 40 so that the protective sheet 7 and the release sheet S are separated, as explained in Figures 13(A) to (C), thereby peeling the release sheet S from the protective sheet 7.

[0051] Thereafter, the second holding step S21, the second fixing step S22 (heating step S23), the peeling step S25, and the removal step S26 are repeated as long as the release sheet S can be reused. The release sheet S may be repeated until no more fixed portions H1, H2, ... can be formed, or it may be repeated for a predetermined number of times.

[0052] For example, if the length of the release sheet S is 100 mm, the area where the adhesive portion can be formed is approximately 30 mm, the length in the extending direction of the portion that is heat-sealed by the heating unit 34 each time is approximately 2 mm, and the spacing between the heat-sealed portions is approximately 2 mm, then the release sheet S can be reused a total of 7 times, saving 6 release sheets S compared to when the release sheet S is disposable.

[0053] Alternatively, after heat-pressing the area on one end Sa of the release sheet S where the fixing portion is formed a predetermined number of times, the gripping position of the gripping portion 40 may be changed from the other end Sb of the release sheet S to the one end Sa, and the fixing portion may be formed using the area on the other end Sb. Furthermore, if the release sheet S is double-sided, the surface of the release sheet S may be used first, and then the back surface of the release sheet S may be used for heat-pressing.

[0054] By peeling the release sheet S from the protective sheet 7 in this way, the release sheet S can be reused, thereby reducing the cost of the release sheet S. Furthermore, reusing the release sheet S reduces waste.

[0055] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to these examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any way without departing from the spirit of the invention.

[0056] For example, in the above-described embodiment, the release sheet supply section 32 of the release sheet fixing unit 30 was located near the center of the holding table 21, and the gripping section 40 was located radially outward from the release sheet supply section 32. However, the embodiment is not limited to this, and the gripping section 40 that grips the other end Sb of the release sheet S may be located near the center of the holding table 21, and the release sheet supply section 32 of the release sheet fixing unit 30 may be located radially outward from the gripping section 40.

[0057] Furthermore, in the first holding step S11 and the second holding step S21, the back surface of the wafer W may be directly held by the holding table 21, or a dicing tape may be attached to the back surface of the wafer W and the ring frame, and the back surface of the wafer W may be held by the holding table 21 via the dicing tape.

[0058] This specification contains at least the following information. Note that the components etc. in parentheses indicate those corresponding to the embodiments described above, but are not limited thereto.

[0059] (1) A sheet peeling method for peeling off a sheet (protective sheet 7) that is fixed to the surface (surface Wa) of a fixed object (wafer W), A first holding step (first holding step S11) is to hold the object to be fixed so that the sheet fixed to the surface to be fixed is exposed, After the first holding step, a first fixing step (first fixing step S12) is performed in which one end (one end Sa) of the release sheet (release sheet S) is fixed to the outer peripheral region of the sheet on the surface of the object to be fixed, After the first fixing step, a peeling step (peeling step S15) is performed to peel the sheet from the surface to be fixed, After the peeling step, a removal step (removal step S16) is performed to remove the peeling sheet from the sheet to which the peeling sheet has been fixed, A second holding step (second holding step S21) is performed to hold the other object to be fixed (wafer W) such that the other sheet (protective sheet 7) fixed to the surface (surface Wa) of the other object to be fixed is exposed, The method further includes a second fixing step (second fixing step S22) in which, after the second holding step, the release sheet removed in the removal step is fixed to the other sheet that is fixed to the surface of the other object to be fixed, Sheet removal method.

[0060] According to (1), the release sheet is removed from the sheet to which it is attached and reused by attaching it to another sheet that is attached to the surface of another object to which it is attached. This reduces the cost of the release sheet. In addition, reusing the release sheet reduces waste.

[0061] (2) The sheet peeling method described in (1), The first fixing step involves fixing the release sheet in an arc shape or linear shape along a direction perpendicular to the extension direction, such that the extension direction of the release sheet is toward the center of the sheet. Sheet removal method.

[0062] According to (2), by forming an arc-shaped or linear fixing portion on the outer periphery of the object to be fixed, the area of ​​the fixing portion can be reduced, and the impact on the object to be fixed can be suppressed.

[0063] (3) The sheet peeling method described in (2), The peeling step involves moving the peeling sheet relative to the extending direction. Sheet removal method.

[0064] According to (3), the release sheet can be properly peeled off by moving it relative to the material along the extension direction, which is the direction in which the adhesive force is relatively stronger.

[0065] (4) The sheet peeling method described in (3), The removal step involves fixing the sheet and removing the release sheet from the sheet while gripping the other end (other end Sb) of the release sheet. Sheet removal method.

[0066] According to (4), the processing time can be shortened by continuing to grip the material with the gripping part during the peeling step and the removal step.

[0067] (5) A sheet peeling method described in any of (2) to (4), The removal step involves removing the release sheet from the sheet by rotating the sheet and the release sheet relative to each other along a direction perpendicular to the extending direction so that the sheet and the release sheet are separated. Sheet removal method.

[0068] According to (5), the release sheet can be properly removed by rotating it relative to the material in a direction perpendicular to the direction of extension, which is the direction in which the adhesive force is relatively weak.

[0069] (6) A sheet peeling method described in any of (2) to (4), The removal step involves removing the release sheet from the sheet by applying an external force to the sheet or the release sheet in a direction perpendicular to the extending direction so that the sheet and the release sheet are separated. Sheet removal method.

[0070] According to (6), the release sheet can be properly removed by applying an external force in a direction perpendicular to the extension direction, which is the direction in which the adhesive force is relatively weaker.

[0071] (7) The sheet peeling method described in (1), The aforementioned release sheet is a heat-sealable sheet that adheres to the sheet when heated. Sheet removal method.

[0072] According to (7), the release sheet can be properly fixed to the sheet.

[0073] (8) The sheet peeling method described in (2), The second fixing step involves fixing the release sheet in an arc shape or linear shape along a direction perpendicular to the extension direction, such that the extension direction of the release sheet is toward the center of the sheet. The fixing portion (fixing portion H2) of the release sheet in the second fixing step is provided at a different position from the fixing portion (fixing portion H1) of the release sheet in the first fixing step. Sheet removal method.

[0074] According to (8), by avoiding the fixed portion of the release sheet that has already been fixed, the reduction in adhesive strength can be suppressed.

[0075] (9) A sheet peeling device (sheet peeling device 10) for peeling off a sheet (protective sheet 7) that is fixed to the surface (surface Wa) of a workpiece (wafer W), A holding unit (holding unit 20) that holds the object to be fixed so that the sheet fixed to the surface to be fixed is exposed, A release sheet fixing unit (release sheet fixing unit 30) fixes one end (one end Sa) of the release sheet (release sheet S) to the outer peripheral region of the sheet on the surface to be fixed held by the holding unit, A gripping portion (gripping portion 40) that grips the other end (other end Sb) of the release sheet, A moving unit (moving unit 50) moves the gripping portion and the holding unit relative to each other, The system includes a removal unit (removal unit 60) for removing the release sheet from the sheet to which the release sheet has been attached after the release sheet has been removed from the object to which it has been attached. Sheet peeling device.

[0076] According to (9), the release sheet is removed from the sheet to which it is attached and reused by attaching it to another sheet that is attached to the surface of another object to which it is attached. This reduces the cost of the release sheet. In addition, reusing the release sheet reduces waste.

[0077] (10) A sheet peeling device as described in (9), The release sheet fixing unit fixes the release sheet in such a way that the extension direction of the release sheet is toward the center of the sheet, and fixes one end of the release sheet in an arc shape or straight line along a direction perpendicular to the extension direction. Sheet peeling device.

[0078] According to (10), by forming an arc-shaped or linear fixing portion on the outer peripheral region of the object to be fixed, the area of ​​the fixing portion can be reduced, and the impact on the object to be fixed can be suppressed.

[0079] (11) The sheet peeling device described in (10), The removal unit has a fixing part (fixing part 62) for fixing the sheet, With the fixing part fixing the sheet and the gripping part gripping the other end of the release sheet, the release sheet is removed from the sheet. Sheet peeling device.

[0080] According to (11), the processing time can be shortened by continuing to grip the material with the gripping part during the peeling step and the removal step.

[0081] (12) A sheet peeling device as described in (10) or (11), The removal unit has a rotating mechanism (rotating mechanism 80) that rotates the gripping portion along a direction perpendicular to the extending direction so that the sheet and the release sheet are separated. Sheet peeling device.

[0082] According to (12), the release sheet can be properly removed by rotating it relative to the material in a direction perpendicular to the direction of extension, which is the direction in which the adhesive force is relatively weak.

[0083] (13) A sheet peeling device as described in (10) or (11), The removal unit has an external force application mechanism (external force application mechanism 70) that applies an external force to the sheet or the release sheet in a direction perpendicular to the extending direction so that the sheet and the release sheet are separated, The external force application mechanism is, A movable body (movable body 72) having an inclined surface that contacts the release sheet and moves away from the sheet as it moves away from the release sheet in a direction perpendicular to the extending direction, The moving body is provided with a drive unit (drive unit 73) that moves the moving body along a direction perpendicular to the extending direction, Sheet peeling device.

[0084] According to (13), the release sheet can be properly removed by applying an external force in a direction perpendicular to the extension direction, which is the direction in which the adhesive force is relatively weak.

[0085] (14) A sheet peeling device according to any one of (9) to (11), The aforementioned release sheet is a heat-sealable sheet that adheres to the sheet when heated. The release sheet fixing unit has a heating section (heating section 34) that heats the release sheet in contact with the sheet in the outer peripheral region of the sheet of the object to be fixed. Sheet peeling device.

[0086] According to (14), the release sheet can be properly fixed to the sheet. [Explanation of symbols]

[0087] 7. Protective sheet (sheet) 10 Sheet peeling device 20 holding units 30 Release sheet fixing unit 40 Gripping part 50 Mobile Units 62 Fixed part 70 External force application mechanism 72 Mobile Units 73 Drive unit 80 Rotation Mechanism S Release Sheet Sa end Sb other end H1 Fixing part H2 Fixing part S11 First holding step S12 First fixing step S15 Peeling step S21 Second holding step S22 Second fixing step W wafer (object to be attached) Wa surface (fixed surface)

Claims

1. A method for peeling off a sheet that is attached to the surface of an object to be attached, A first holding step involves holding the object to be fixed so that the sheet fixed to the surface to be fixed is exposed, After the first holding step, a first fixing step is performed in which one end of the release sheet is fixed to the outer peripheral region of the sheet on the surface of the object to be fixed, After the first fixing step, a peeling step is performed to peel the sheet from the surface to be fixed, After the peeling step, a removal step is performed to remove the peeling sheet from the sheet to which the peeling sheet has been fixed, A second holding step involves holding the other object to be fixed such that other sheets fixed to the surface of the other object to be fixed are exposed, The method further comprises a second fixing step, after the second holding step, fixing the release sheet removed in the removal step to the other sheet that is fixed to the surface of the other object to be fixed, Sheet removal method.

2. A sheet peeling method according to claim 1, The first fixing step involves fixing the release sheet in an arc shape or linear shape along a direction perpendicular to the extension direction, such that the extension direction of the release sheet is toward the center of the sheet. Sheet removal method.

3. A sheet peeling method according to claim 2, The peeling step involves moving the peeling sheet relative to the extending direction. Sheet removal method.

4. A sheet peeling method according to claim 3, The removal step involves fixing the sheet and removing the release sheet from the sheet while gripping the other end of the release sheet. Sheet removal method.

5. A sheet peeling method according to any one of claims 2 to 4, The removal step involves removing the release sheet from the sheet by rotating the sheet and the release sheet relative to each other along a direction perpendicular to the extending direction so that the sheet and the release sheet are separated. Sheet removal method.

6. A sheet peeling method according to any one of claims 2 to 4, The removal step involves removing the release sheet from the sheet by applying an external force to the sheet or the release sheet in a direction perpendicular to the extending direction so that the sheet and the release sheet are separated. Sheet removal method.

7. A sheet peeling method according to claim 1, The aforementioned release sheet is a heat-sealable sheet that adheres to the sheet when heated. Sheet removal method.

8. A sheet peeling method according to claim 2, The second fixing step involves fixing the release sheet in an arc shape or linear shape along a direction perpendicular to the extension direction, such that the extension direction of the release sheet is toward the center of the sheet. The fixing portion of the release sheet in the second fixing step is provided at a different position from the fixing portion of the release sheet in the first fixing step. Sheet removal method.

9. A sheet peeling device for peeling off a sheet that is fixed to the surface of an object to be fixed, A holding unit that holds the object to be fixed such that the sheet fixed to the surface to be fixed is exposed, A release sheet fixing unit that fixes one end of the release sheet to the outer peripheral region of the sheet to be fixed surface held by the holding unit, A gripping portion for gripping the other end of the release sheet, A moving unit that moves the gripping portion and the holding unit relative to each other, The system includes a removal unit for removing the release sheet from the sheet to which the release sheet has been attached after the sheet has been peeled off from the object to which it has been attached. Sheet peeling device.

10. A sheet peeling device according to claim 9, The release sheet fixing unit fixes the release sheet in such a way that the extension direction of the release sheet is toward the center of the sheet, and fixes one end of the release sheet in an arc shape or straight line along a direction perpendicular to the extension direction. Sheet peeling device.

11. A sheet peeling device according to claim 10, The removal unit has a fixing part for fixing the sheet, With the fixing part fixing the sheet and the gripping part gripping the other end of the release sheet, the release sheet is removed from the sheet. Sheet peeling device.

12. A sheet peeling device according to claim 10 or 11, The removal unit has a rotation mechanism that rotates the gripping portion along a direction perpendicular to the extending direction so that the sheet and the release sheet are separated. Sheet peeling device.

13. A sheet peeling device according to claim 10 or 11, The removal unit has an external force application mechanism that applies an external force to the sheet or the release sheet in a direction perpendicular to the extending direction so that the sheet and the release sheet are separated. The external force application mechanism is, A moving body having an inclined surface that contacts the release sheet and moves away from the sheet as it moves away from the release sheet in a direction perpendicular to the extending direction, The moving body comprises a drive unit that moves the moving body along a direction perpendicular to the extending direction, Sheet peeling device.

14. A sheet peeling device according to any one of claims 9 to 11, The aforementioned release sheet is a heat-sealable sheet that adheres to the sheet when heated. The release sheet fixing unit has a heating section that heats the release sheet in contact with the sheet in the outer peripheral region of the sheet of the object to be fixed. Sheet peeling device.

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