Method of processing workpieces

Abstract

To provide a processing method of a workpiece in which a thinned workpiece can be peeled off from a support substrate without damaging the workpiece.SOLUTION: A processing method of a workpiece comprises: a support substrate fixing step 1 of fixing a support substrate on one surface of a workpiece via wax; a grinding step 2 of grinding the other surface side of the workpiece on one surface of which the support substrate is fixed, and thinning to a predetermined thickness; a protective sheet laying step 3 of laying a protective sheet containing thermoplastic resin to a grinding surface of the workpiece that was ground in the grinding step 2; a heating step 4 of heating the protective sheet and wax in the state where the protective sheet is laid on the grinding surface to thermally press a heated protective sheet to the workpiece; and a support substrate peeling step 5 of peeling off the workpiece from the support substrate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for processing a workpiece. [Background Art]

[0002] In a semiconductor device manufacturing process, a step of grinding the back surface of a semiconductor wafer to reduce the thickness thereof is performed in order to adjust the device to a desired thickness. In recent years, due to the miniaturization of devices on which semiconductor devices are mounted, there has been a demand for making device chips as thin as possible. However, since thinned semiconductor wafers become difficult to handle, a method is used in which the front side of a semiconductor wafer is attached to a supporting substrate before grinding, and the semiconductor wafer is peeled off from the supporting substrate after grinding (see Patent Document 1). [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2010-027857 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] Incidentally, as a method for attaching the supporting substrate, a common method is to form a wax film using solid wax melted by heating, and fix the semiconductor wafer and the supporting substrate via the wax film. However, when fixed by such a method, when peeling the semiconductor wafer from the supporting substrate, warp caused by grinding stress or the like is released, and there is a possibility that the semiconductor wafer may crack.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a method for processing a workpiece that allows a thinned workpiece to be peeled from a supporting substrate without damaging the workpiece. [Means for Solving the Problem]

[0006] To solve the above-mentioned problems and achieve the objective, the present invention provides a method for processing a workpiece, comprising: a support substrate fixing step of fixing a support substrate to one side of the workpiece via wax; a grinding step of grinding the other side of the workpiece to which the support substrate is fixed to the one side to thin it to a predetermined thickness; a protective sheet laying step of laying a protective sheet containing a thermoplastic resin on the ground surface of the workpiece ground in the grinding step; a heating step of heating the protective sheet and the wax while the protective sheet is laid on the ground surface, and heat-pressing the heated protective sheet onto the workpiece; and a support substrate peeling step of peeling the workpiece from the support substrate.

[0007] Furthermore, in the method for processing a workpiece according to the present invention, it is preferable that the melting temperature of the wax is lower than the temperature at which the protective sheet is heat-pressed onto the workpiece. [Effects of the Invention]

[0008] The present invention allows a thinned workpiece to be peeled off the support substrate without damaging it. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a flowchart showing the flow of the workpiece processing method according to the embodiment. [Figure 2] Figure 2 is a perspective view showing an example of the support substrate fixing step shown in Figure 1. [Figure 3] Figure 3 is a perspective view showing another example of the support substrate fixing step shown in Figure 1. [Figure 4] Figure 4 is a side view showing a partial cross-section of one state of the grinding step shown in Figure 1. [Figure 5] Figure 5 is a side view showing a partial cross-section of one state of the grinding step shown in Figure 1. [Figure 6] Figure 6 is a side view showing a partial cross-section of one state of the protective sheet laying step shown in Figure 1. [Figure 7]Figure 7 is a side view showing a partial cross-section of one state of the heating step shown in Figure 1. [Figure 8] Figure 8 is a side view showing a partial cross-section of one state of the support substrate peeling step shown in Figure 1. [Figure 9] Figure 9 is a side view showing a partial cross-section of one state of the modified layer formation step in the first application embodiment. [Figure 10] Figure 10 is a side view showing a partial cross-section of one state of the modified layer formation step in the second application embodiment. [Figure 11] Figure 11 is a side view showing a partial cross-section of one state of the division step in the second application embodiment. [Figure 12] Figure 12 is a side view showing a partial cross-section of one state of the division step in the second application embodiment. [Modes for carrying out the invention]

[0010] Embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by those skilled in the art, and those that are substantially the same. Moreover, the components described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the present invention.

[0011] [Embodiment] A method for processing a workpiece 10 according to an embodiment of the present invention will be described with reference to the drawings. Figure 1 is a flowchart showing the flow of the method for processing a workpiece 10 according to the embodiment. The method for processing a workpiece 10 involves grinding the workpiece 10 while it is fixed to a support substrate 30, then laying a protective sheet 50 on the workpiece 10 and peeling the support substrate 30 off the workpiece 10. As shown in Figure 1, the method for processing a workpiece 10 according to the embodiment comprises a support substrate fixing step 1, a grinding step 2, a protective sheet laying step 3, a heating step 4, and a support substrate peeling step 5.

[0012] (Support substrate fixing step 1) FIG. 2 is a perspective view showing an example of the support substrate fixing step 1 shown in FIG. 1. FIG. 3 is a perspective view showing another example of the support substrate fixing step 1 shown in FIG. 1. The support substrate fixing step 1 is a step of fixing a support substrate 30 to one surface 11 of a workpiece 10 via wax 20.

[0013] The workpiece 10 is a wafer such as a disk-shaped semiconductor device wafer or an optical device wafer that uses, for example, silicon (Si), sapphire (Al2O3), gallium arsenide (GaAs), silicon carbide (SiC), or lithium tantalate (LiTaO3) or the like as a substrate. The workpiece 10 has a plurality of scheduled division lines set in a grid pattern on the surface (one surface 11) of the substrate (refer to the scheduled division lines 15 in FIG. 9 to FIG. 12), and devices formed in regions divided by the scheduled division lines.

[0014] The devices are, for example, integrated circuits such as IC (Integrated Circuit) or LSI (Large Scale Integration), image sensors such as CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor), or MEMS (Micro Electro Mechanical Systems) or the like. The workpiece 10 is divided into individual devices along the scheduled division lines and manufactured into chips. Each chip includes a part of the substrate and the device on the substrate. The planar shape of the chip is, for example, a square shape or a rectangular shape. In the present invention, the workpiece 10 is not limited to a disk shape, and may be other plate shapes such as a resin package substrate or a metal substrate.

[0015] The wax 20 is a bonding material for fixing one surface 11 of the workpiece 10 to the support substrate 30, and is formed of, for example, a thermoplastic resin. The wax 20 has a melting initiation temperature of about 60°C, and the melting temperature is lower than the temperature at which the protection sheet 50 described below is thermocompression-bonded to the workpiece 10. In this specification, the term thermocompression bonding refers to, for example, that the protection sheet 50 is softened without being melted and is pressed against the ground surface 14 (see FIG. 5) of the workpiece 10 after grinding, so as to be adhered to the ground surface 14.

[0016] In the example shown in FIG. 2, the support substrate 30 is in the shape of a circular disk having the same diameter as that of the workpiece 10. In addition, in the support substrate fixing step S1, as shown in another example in FIG. 3, a disc-shaped support substrate 30-1 having a larger diameter than that of the workpiece 10 may also be used. Alternatively, the support substrate may be formed in a shape and size that sufficiently covers the workpiece 10. One surface 31 and the other surface 32 of the support substrate 30 are formed parallel to each other. The support substrate 30 is made of a material that is equally or less brittle than the workpiece 10, and is equally or less prone to cracking than the workpiece 10. For example, a glass plate, a silicon wafer or the like is used as the support substrate 30.

[0017] In the support substrate fixing step S1, for example, first, the wax 20 is applied to one of the one surface 11 of the workpiece 10 and the one surface 31 of the support substrate 30. Next, the surface coated with the wax 20 among the one surface 11 of the workpiece 10 and the one surface 31 of the support substrate 30 is bonded to the other surface. For example, after the liquefied wax 20 is applied to the one surface 11 of the workpiece 10 by spin coating, it is fixed by pressing against the one surface 31 of the heated support substrate 30.

[0018] Alternatively, the solid wax 20 may be interposed between the one surface 11 of the workpiece 10 and the one surface 31 of the support substrate 30, and then heated and pressed to melt the wax 20 and spread it over the entire surface of the workpiece 10. When the wax 20 cools down to below its softening point, it cures, and the workpiece 10 can be fixed to the support substrate 30 via the cured wax 20.

[0019] (Grinding step 2) Figures 4 and 5 are side views showing a partial cross-section of one state of grinding step 2 shown in Figure 1. Grinding step 2 is a step in which the other side 12 of the workpiece 10, to which a support substrate 30 is fixed on one side 11, is ground to thin it to a predetermined thickness 13. In grinding step 2 of the embodiment, the other side 12 of the workpiece 10 is ground using the grinding apparatus 40 shown in Figures 4 and 5 to thin it to a predetermined thickness 13.

[0020] As shown in Figures 4 and 5, the grinding apparatus 40 comprises a holding table 41, a spindle 42 which is a rotating shaft member, a grinding wheel 43 attached to the lower end of the spindle 42, a grinding wheel 44 mounted on the lower surface of the grinding wheel 43, and a grinding fluid supply unit (not shown). The grinding wheel 43 rotates on a rotation axis parallel to the axis of the holding table 41.

[0021] In grinding step 2, first, the other side 32 of the support substrate 30 is held by suction to the holding surface of the holding table 41. Next, with the holding table 41 rotating around its axis, the grinding wheel 43 is rotated around its axis. Grinding fluid is supplied to the processing point by a grinding fluid supply unit (not shown), and the grinding wheel 44 of the grinding wheel 43 is brought closer to the holding table 41 at a predetermined feed rate, thereby grinding the other side 12 of the workpiece 10 with the grinding wheel 44 and thinning it to a predetermined thickness 13 as shown in Figure 5.

[0022] (Protective sheet installation step 3) Figure 6 is a side view showing a partial cross-section of one state of the protective sheet laying step 3 shown in Figure 1. Protective sheet laying step 3 is a step in which a protective sheet 50 containing thermoplastic resin is laid on the ground surface 14 of the workpiece 10 that has been ground in grinding step 2. In protective sheet laying step 3 of this embodiment, the protective sheet 50 is pressed against the ground surface 14 of the workpiece 10 by the roller 55 shown in Figure 6.

[0023] The protective sheet 50 is a sheet for protecting the grinding surface 14 side of the workpiece 10. The protective sheet 50 is a resin sheet made of a thermoplastic resin that is heat-pressed at a temperature of about 80°C to 120°C. The protective sheet 50 includes, for example, a polyolefin sheet or polyethylene sheet with a thickness of 20 μm to 80 μm, and in this embodiment, it is a sheet with a thickness of 80 μm. The protective sheet 50 may be a single layer or laminated. The protective sheet 50 is, for example, a GluFree® sheet manufactured by DISCO Corporation, which does not have an adhesive layer and consists only of a non-adhesive and stretchable base layer.

[0024] In protective sheet laying step 3, first, the other side 32 of the support substrate 30 is placed on the holding surface of the holding table 56 so that the grinding surface 14 side of the workpiece 10 faces upward. Next, in protective sheet laying step 3, one side 51 of the protective sheet 50, which is larger than the workpiece 10 and covers the entire grinding surface 14, is positioned facing the grinding surface 14 of the workpiece 10.

[0025] In protective sheet laying step 3, the roller 55 is then rolled on one side 51 of the protective sheet 50 and the other side 52 opposite to it, from one end to the other of the workpiece 10. This presses the protective sheet 50 against the grinding surface 14 of the workpiece 10. The roller 55 may, for example, have a heat source and be able to heat the protective sheet 50. As the protective sheet 50 is heated and heat-pressed by the roller 55, it is softened and spread out on the grinding surface 14, which prevents air bubbles from entering between the grinding surface 14 and the protective sheet 50 in the heating step 4 described later.

[0026] (Heating step 4) Figure 7 is a side view showing a partial cross-section of one state of heating step 4 shown in Figure 1. Heating step 4 is a step in which the protective sheet 50 and wax 20 are heated with the protective sheet 50 laid on the grinding surface 14, and the heated protective sheet 50 is heat-pressed onto the workpiece 10. In heating step 4 of this embodiment, the protective sheet 50 and wax 20 are heated by the heating device 60 shown in Figure 7.

[0027] The heating device 60 is a hot plate having a heat source 61 and capable of heating the holding surface 62 (upper surface). The holding table 56 used in the protective sheet laying step 3 may also be the heating device 60 in a state where heating by the heat source 61 has been stopped. In the heating step 4, the other side 32 of the support substrate 30 is placed on the holding surface 62 of the heated heating device 60, thereby heating the wax 20 and protective sheet 50 via the support substrate 30 and the workpiece 10.

[0028] In this process, the heating temperature of the heat source 61 is preset so that the protective sheet 50 is heated to a temperature above its softening point and below its melting point, and the wax 20 is heated to a temperature above its softening point. Specifically, the protective sheet 50 and the wax 20 are heated to a temperature of approximately 50°C to 200°C. More specifically, since the melting start temperature of the wax 20 is approximately 60°C and the pressure bonding temperature of the protective sheet 50 is approximately 80°C to 120°C, it is preferable that they be heated to a temperature of approximately 80°C to 120°C.

[0029] The protective sheet 50 laid on the grinding surface 14 of the workpiece 10 softens when heated, and one side 51 adheres closely to the grinding surface 14. Also, since the melting temperature of the wax 20 is lower than the temperature at which the protective sheet 50 is heat-pressed onto the workpiece 10, the wax 20 interposed between the workpiece 10 and the support substrate 30 melts when the protective sheet 50 is heated to the point of heat-pressing onto the workpiece 10.

[0030] In addition, heating step 4 is not limited to heating on a hot plate; any method that allows the wax 20 and protective sheet 50 to be heated simultaneously is acceptable.

[0031] (Support substrate removal step 5) Figure 8 is a side view showing a partial cross-section of one state of the support substrate peeling step 5 shown in Figure 1. The support substrate peeling step 5 is a step in which the workpiece 10 is peeled off the support substrate 30. In the support substrate peeling step 5, the workpiece 10 is peeled off the support substrate 30 by lifting the protective sheet 50, which was heat-pressed onto the workpiece 10 in the heating step 4, and the workpiece 10, which is placed on the holding surface 62 of the heating device 60. Since the wax 20 is sufficiently heated and melted in the heating step 4, the workpiece 10 can be easily peeled off the support substrate 30. Therefore, the workpiece 10 can be peeled off the wax 20 without releasing the warping caused by grinding stress, etc.

[0032] When the workpiece 10 is peeled from the support substrate 30, the protective sheet 50 is removed from the heating device 60 along with the workpiece 10. As the protective sheet 50 cools and falls below its softening point, it hardens and integrates with the workpiece 10. In this way, the workpiece 10 can be peeled from the wax 20 and transferred to the protective sheet 50.

[0033] As described above, the method for processing the workpiece 10 according to the embodiment involves grinding the back surface (the other surface 12) of the workpiece 10 fixed to the support substrate 30 with wax 20, and then laying a protective sheet 50 made of thermoplastic resin on the ground surface 14 and heating it to remove the wax 20 and integrate the protective sheet 50 with the ground surface 14. This has the effect of removing the workpiece 10 from the wax 20 without releasing the warp, and transferring the workpiece 10 to the protective sheet 50.

[0034] [First application form] Next, a first application embodiment of the method for processing the workpiece 10 of the present invention will be described. In the first application embodiment, after the support substrate fixing step 1 and before the grinding step 2, a modified layer 16 (see Figure 9) is formed inside the workpiece 10 (modified layer formation step), and in the grinding step 2, the modified layer 16 is removed and the workpiece 10 is divided along the modified layer 16 to form chips.

[0035] The modified layer 16 refers to a region whose density, refractive index, mechanical strength, or other physical properties are different from those of the surrounding area. The modified layer 16 may include, for example, a melted region, a cracked region, a dielectric breakdown region, a refractive index change region, or a region where these regions are mixed. The modified layer 16 has lower mechanical strength, etc., than other parts of the workpiece 10.

[0036] (Modified layer formation step) Figure 9 is a side view showing a partial cross-section of one state of the modified layer formation step in the first application embodiment. In the modified layer formation step shown in Figure 9, a modified layer 16 is formed inside the workpiece 10 by stealth dicing using a laser processing apparatus 70. The laser processing apparatus 70 comprises a holding table 71, a laser beam irradiation unit 72, an imaging unit (not shown), and a moving unit (not shown) that moves the holding table 71 and the laser beam irradiation unit 72 relative to each other.

[0037] In the modified layer formation step shown in Figure 9, first, the other side 32 of the support substrate 30 is held by suction to the holding table 71. Next, the holding table 71 is moved to a predetermined processing position by a moving unit (not shown). Then, the workpiece 10 is imaged by an imaging unit (not shown) to detect the division line 15. Once the division line 15 is detected, alignment is performed to align the division line 15 of the workpiece 10 with the irradiation part of the laser beam irradiation unit 72.

[0038] In the modified layer formation step, the focal point 74 of the laser beam 73 is then positioned inside the workpiece 10. In this state, the focal point 74 is moved relative to the planned division line 15 in the processing feed direction while the laser beam 73 is irradiated from the other side 12 of the workpiece 10. The laser beam 73 is a laser beam with a wavelength that is penetrating to the workpiece 10, for example, infrared rays (IR). As the laser beam 73 is irradiated along the planned division line 15, a modified layer 16 is formed inside the workpiece 10 along the planned division line 15.

[0039] In this case, during the modified layer formation step, the laser beam 73 may be irradiated multiple times by changing the height of the focal point 74 of the laser beam 73, or multiple modified layers 16 overlapping in the thickness direction of the workpiece 10 may be formed by irradiating with a laser beam 73 having multiple focal points 74 that are separated in the thickness direction of the workpiece 10. Cracks 17 extend from the modified layer 16 in the thickness direction of the workpiece 10, and the connection between the modified layer 16 and the cracks 17 forms a grid of dividing starting points along the planned dividing line 15.

[0040] (Grinding step 2) In the first application embodiment, the procedure for grinding the other side 12 of the workpiece 10 on which the modified layer 16 is formed is the same as grinding step 2 in the embodiment. In grinding step 2 of the first application embodiment, the grinding stress acting from the grinding wheel 43 (see Figures 4 and 5) causes cracks to extend from the modified layer 16 to one side 11 and the other side 12 of the workpiece 10, and the modified layer 16 is used as the dividing point to divide along the planned dividing line 15, thereby separating into individual device chips.

[0041] [Second application form] Next, a second application embodiment of the processing method for the workpiece 10 of the present invention will be described. In the second application embodiment, after the grinding step 2 and before the protective sheet laying step 3, a modified layer 16 is formed inside the workpiece 10 (modified layer formation step), and after the support substrate peeling step 5, the workpiece 10 is divided along the modified layer 16 by expansion to form chips (dividing step).

[0042] (Modified layer formation step) Figure 10 is a side view showing a partial cross-section of one state of the modified layer formation step in the second application embodiment. In the modified layer formation step shown in Figure 10, a modified layer 16 is formed inside the workpiece 10 by stealth dicing using a laser processing device 70, similar to the modified layer formation step in the first application embodiment. The procedure for the modified layer formation step in the second application embodiment is obtained by replacing "the other surface 12 of the workpiece 10" with "the ground surface 14 of the workpiece 10" in the procedure for the modified layer formation step in the first application embodiment.

[0043] (Division step) Figures 11 and 12 are side views showing a partial cross-section of one state of the splitting step in the second application embodiment. The splitting step is performed on the workpiece 10, which has a modified layer 16 formed inside in the modified layer formation step, after the protective sheet laying step 3, heating step 4, and support substrate peeling step 5 have been performed. In the splitting step, an external force is applied to the workpiece 10, which has a modified layer 16 formed inside in the modified layer formation step, and it is split along each planned splitting line 15 to form chips.

[0044] As shown in Figures 11 and 12, in the splitting step, the expandable tape 91 is attached to one side 11 of the workpiece 10 and transferred, and then the expansion device 80 splits the workpiece 10 by applying an external force radially to the expandable tape 91. The expansion device 80 comprises a holding table 81, a clamping member 82, a lifting unit 83, a push-up member 84, and a roller member 85. The push-up member 84 is cylindrical in shape and is provided on the outer circumference and coaxially with the holding table 81. The roller member 85 is rotatably provided on the same plane as or slightly above the holding surface of the holding table 81 and at the upper end of the push-up member 84.

[0045] In the splitting step, first, the protective sheet 50 (see Figure 8) attached to the grinding surface 14 side of the workpiece 10 is peeled off, and the expandable tape 91 is attached to one side 11 of the workpiece 10 and the annular frame 90. The frame 90 is made of metal or resin and is an annular plate shape with an opening larger than the outer diameter of the workpiece 10. The expandable tape 91 is a sheet-like material comprising, for example, a base layer made of expandable synthetic resin and an adhesive layer laminated on the base layer and made of expandable and adhesive synthetic resin.

[0046] The expandable tape 91 is, for example, attached to one side 11 of the workpiece 10 and the annular frame 90, and then cut to a shape and size that covers the opening of the frame 90. The workpiece 10 is positioned in a predetermined position in the opening of the frame 90 and fixed to the frame 90 and the expandable tape 91 by having one side 11 attached to the expandable tape 91.

[0047] As shown in Figure 11, in the splitting step, one side 11 of the workpiece 10 is then placed on the holding surface of the holding table 81 via the expandable tape 91, and the outer circumference of the frame 90 is fixed with the clamping member 82. At this time, the roller member 85 comes into contact with the expandable tape 91 between the inner edge of the frame 90 and the outer edge of the workpiece 10.

[0048] As shown in Figure 11, in the splitting step, the lifting unit 83 then raises the holding table 81 and the push-up member 84 together. At this time, since the outer circumference of the expanded tape 91 is fixed by the clamp member 82 via the frame 90, the portion between the inner edge of the frame 90 and the outer edge of the workpiece 10 is expanded in the planar direction. Furthermore, the roller member 85 provided at the upper end of the push-up member 84 reduces friction with the expanded tape 91.

[0049] In the splitting step, as a result of the expansion of the expandable tape 91, radial tensile forces act on the expandable tape 91. When radial tensile forces act on the expandable tape 91, as shown in Figures 10 and 11, the workpiece 10 to which the expandable tape 91 is attached is split along the modified layer 16 along the planned splitting line 15, with the fracture starting point, and is divided into individual device chips 18.

[0050] After the workpiece 10 is divided into device chips 18, for example, in the pickup process, the device chips 18 are picked up from the expanded tape 91 using a well-known picker. In the division step of the second application embodiment, the device chips 18 are separated into individual pieces with the back side (grinding surface 14) facing upwards, so for example, in the next pickup process or die bonding process, it is necessary to invert the top and bottom of the device chips 18.

[0051] In the second application embodiment described above, a different tape from the protective sheet 50 is used as the expandable tape 91. However, if the protective sheet 50 is expandable, the protective sheet 50 can be used as is. In this case, in the splitting step, the device chip 18 is separated into individual pieces with one surface (one side 11) facing upwards. Therefore, for example, in the next pick-up step or die bonding step, it is not necessary to invert the device chip 18.

[0052] It should be noted that the present invention is not limited to the embodiments described above. That is, it can be implemented with various modifications without departing from the core principles of the present invention. For example, in protective sheet laying step 3, the protective sheet 50 may be laid in close contact with the grinding surface 14 by creating a vacuum state (low pressure state). [Explanation of symbols]

[0053] 10 Workpiece 11, 31, 51 One side 12, 32, 52 The other side 13 Thickness 14. Grinding surface 15 planned division lines 16 Modified layer 17 Crack 18 device chips 20 waxes 30, 30-1 Support substrate 50 protective sheets

Claims

1. A method for processing a workpiece, A support substrate fixing step involves fixing the support substrate to one side of the workpiece via wax, A grinding step in which the other side of the workpiece, to which the support substrate is fixed on one side, is ground to thin it to a predetermined thickness, A protective sheet laying step is to lay a protective sheet containing a thermoplastic resin on the ground surface of the workpiece that has been ground in the grinding step, A heating step involves heating the protective sheet and the wax while the protective sheet is laid on the grinding surface, and then heat-pressing the heated protective sheet onto the workpiece. The system includes a support substrate peeling step of peeling the workpiece from the support substrate. A method for processing a workpiece, characterized by the following features.

2. The melting temperature of the wax is lower than the temperature at which the protective sheet is heat-pressed onto the workpiece. A method for processing a workpiece according to claim 1, characterized in that

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