Processing method of workpiece

Abstract

To provide a workpiece processing method capable of surely peeling off a sheet fixed to a workpiece by thermocompression bonding.SOLUTION: A processing method of a workpiece to process a workpiece includes: a thermocompression bonding step of thermocompression bonding a first sheet made of a thermoplastic resin to the surface side of the workpiece by placing the first sheet on the surface side of the workpiece and heating the first sheet; a processing step of processing the workpiece together with the first sheet; and a stripping step of stripping the first sheet from the workpiece by moving the second sheet after placing the second sheet made of a thermoplastic resin on the processed first sheet and heating it to bond the second sheet to the first sheet by thermocompression.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for processing a workpiece such as a wafer. [Background technology]

[0002] The device chip manufacturing process uses a wafer in which devices are formed in multiple areas defined by multiple streets (planned division lines) arranged in a grid pattern. By dividing this wafer along the streets, multiple device chips, each equipped with a device, are obtained. The device chips are incorporated into various electronic devices, such as mobile phones and personal computers.

[0003] A cutting device is used to divide wafers. The cutting device is equipped with a chuck table that holds the workpiece and a cutting unit that cuts the workpiece, and the cutting unit is equipped with an annular cutting blade. The wafer is held on the chuck table and the cutting blade is rotated to cut into the wafer, thereby cutting and dividing the wafer.

[0004] In recent years, development has also progressed in processes for dividing wafers by laser processing using laser processing equipment. Laser processing equipment is equipped with a chuck table that holds the workpiece and a laser irradiation unit that irradiates it with a laser beam of a specified wavelength. By holding the wafer on the chuck table and irradiating it with a laser beam from the laser irradiation unit, the wafer is subjected to ablation processing or the like, and divided into pieces.

[0005] When wafers are processed using processing equipment such as cutting equipment and laser processing equipment, chips (processing chips) generated by the wafer processing are scattered. For example, when a wafer is cut using a cutting equipment, chips are generated at the contact area between the wafer and the cutting blade. Furthermore, when a wafer is laser processed using a laser processing equipment, molten material (debris) is generated in the area of ​​the wafer irradiated with the laser beam. When chips, debris, and other processing chips are scattered, there is a risk that the front side of the wafer (the side on which devices are formed) will be contaminated by the processing chips.

[0006] Therefore, when processing a wafer using a processing device, a protective tape (adhesive tape) is applied to the front surface of the wafer (see Patent Document 1). The protective tape includes a base material and an adhesive applied to the surface of the base material, and is applied so that the adhesive side contacts the front surface of the wafer. The workpiece is then processed together with the protective tape, with the front surface covered by the protective tape. This prevents processing debris from adhering to the front surface of the wafer.

[0007] The protective tape is peeled off and removed from the workpiece after processing the workpiece. At that time, some of the adhesive remains on the front side of the wafer, and the front side of the wafer may be contaminated by the adhesive residue. Therefore, a processing method using a thermocompression sheet that does not contain an adhesive instead of the protective tape has been proposed (see Patent Document 2). When a thermocompression sheet is used, no adhesive remains on the wafer even when the thermocompression sheet is peeled off after wafer processing, so contamination by adhesive residue can be avoided. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-134390 [Patent Document 2] Japanese Patent Publication No. 2020-77812 Summary of the Invention [Problem to be solved by the invention]

[0009] As mentioned above, when a sheet that does not contain an adhesive (thermocompression sheet) is used to process a workpiece such as a wafer, the sheet is heated to soften it and thermocompression bonded to the workpiece. After the processing of the workpiece is completed, a release tape is applied to the sheet and the release tape is moved away from the workpiece, thereby peeling and removing the sheet together with the release tape from the workpiece.

[0010] However, when a sheet is thermocompression-bonded to a workpiece, the softened sheet deforms to conform to the shape of the surface of the workpiece and adheres firmly to the workpiece. Therefore, even if a release tape is applied to the sheet and an attempt is made to peel the sheet from the workpiece, the bond between the workpiece and the sheet is stronger than the bond between the sheet and the release tape, and the release tape may come off the sheet during the peeling process. In other words, when a sheet is thermocompression-bonded to a workpiece, there is a problem in that it becomes difficult to peel the sheet from the workpiece after processing.

[0011] The present invention has been made in view of the above problems, and aims to provide a method for processing a workpiece that can reliably peel off a sheet fixed to the workpiece by thermocompression bonding. [Means for solving the problem]

[0012] According to one aspect of the present invention, there is provided a method for processing a workpiece, the method comprising: a thermocompression bonding step of placing a first sheet made of a thermoplastic resin on a surface side of the workpiece and heating the first sheet to thermocompression bond the first sheet to the surface side of the workpiece; a processing step of processing the workpiece together with the first sheet; and a peeling step of placing a second sheet made of a thermoplastic resin on the processed first sheet and heating the second sheet to thermocompression bond the second sheet to the first sheet, and then moving the second sheet to peel the first sheet from the workpiece. The second sheet is made of the same material as the first sheet or has a lower melting point than the first sheet. A method for processing a workpiece is provided.

[0013] Preferably, in the processing step, the workpiece and the first sheet are processed together by cutting a cutting blade into the workpiece and the first sheet, or by irradiating a laser beam onto the workpiece and the first sheet, or by supplying a plasma-state gas to the workpiece and the first sheet.

[0014] Preferably, the method for processing a workpiece further includes, before the processing step, a support member arranging step of arranging a support member on the back side of the workpiece. Also, preferably, the method for processing a workpiece further includes, before the peeling step, an integration step of heating and melting the processed first sheet to integrate the processed first sheet. Preferably, the first sheet and the second sheet do not contain an adhesive. Preferably, in the peeling step, the second sheet covers the entire first sheet.

[0015] Preferably, a device is formed on the surface side of the workpiece. [Effects of the Invention]

[0016] In one aspect of the present invention, a method for processing a workpiece includes thermocompression bonding a second sheet to a processed first sheet, and then moving the second sheet to peel the first sheet from the workpiece. This allows the first sheet to be peeled off while maintaining high adhesion between the first and second sheets, preventing separation of the first and second sheets during peeling. As a result, the first sheet, which is firmly fixed to the workpiece by thermocompression, can be reliably peeled off. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. [Figure 2] 1 is a flowchart showing a method for processing a workpiece. [Figure 3] FIG. 3(A) is a perspective view showing a workpiece on which a first sheet is placed, and FIG. 3(B) is a perspective view showing a workpiece to which the first sheet is thermocompression bonded. [Figure 4]FIG. 4(A) is a perspective view showing the workpiece and the support member in the support member arranging step, and FIG. 4(B) is a perspective view showing the workpiece and the support member after the support member arranging step. [Figure 5] FIG. [Figure 6] FIG. 1 is a perspective view showing a laser processing device. [Figure 7] 1 is a partial cross-sectional front view showing a plasma processing apparatus. [Figure 8] 1 is a cross-sectional view showing a portion of a workpiece to be plasma etched; [Figure 9] FIG. 9(A) is a perspective view showing the workpiece and the first sheet in the integration step, and FIG. 9(B) is a perspective view showing the workpiece and the first sheet after the integration step. [Figure 10] FIG. [Figure 11] FIG. 11(A) is a partial cross-sectional front view showing the first sheet to which the second sheet has been thermocompression-bonded, and FIG. 11(B) is a partial cross-sectional front view showing the first sheet being peeled off from the workpiece. [Figure 12] FIG. 12(A) is a perspective view showing a first sheet to which a second sheet is thermocompression bonded, and FIG. 12(B) is a perspective view showing the first sheet being peeled off from the workpiece. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. First, an example of the structure of a workpiece that can be processed by the method for processing a workpiece according to this embodiment will be described. Figure 1 is a perspective view showing a workpiece 11.

[0019] For example, the workpiece 11 is a disk-shaped wafer made of a semiconductor material such as single crystal silicon, and includes a front surface (first surface) 11a and a back surface (second surface) 11b that are generally parallel to each other. The workpiece 11 is divided into a plurality of rectangular regions by streets (planned division lines) 13 that are arranged in a grid pattern so as to intersect with each other. Furthermore, devices 15, such as ICs (Integrated Circuits), LSIs (Large Scale Integration), LEDs (Light Emitting Diodes), and MEMS (Micro Electro Mechanical Systems) devices, are formed on the front surface 11a side of each of the plurality of regions divided by the streets 13.

[0020] However, there are no limitations on the material, shape, structure, size, etc. of the workpiece 11. For example, the workpiece 11 may be a wafer (substrate) made of a material such as a semiconductor other than silicon (GaAs, InP, GaN, SiC, etc.), sapphire, glass, ceramics, resin, metal, etc. Furthermore, there are no limitations on the type, number, shape, structure, size, arrangement, etc. of the devices 15.

[0021] By dividing the workpiece 11 along the streets 13, device chips each including a device 15 are manufactured. Note that a structure such as a TEG (Test Element Group) for inspecting the device 15 may be provided on the front surface 11a side of the workpiece 11. Furthermore, the workpiece 11 may be provided with an electrode (via electrode) that penetrates the workpiece 11 in the thickness direction.

[0022] For example, the workpiece 11 is processed using a processing device such as a cutting device, a laser processing device, or a plasma processing device, and divided into a plurality of device chips. A specific example of a method for processing the workpiece 11 will be described below. Figure 2 is a flowchart showing the method for processing the workpiece 11.

[0023] First, a thermocompression bonding step (step S1) is performed in which a first sheet made of a thermoplastic resin is thermocompression bonded to the front surface 11a of the workpiece 11. The workpiece 11 in the thermocompression bonding step is shown in Figures 3(A) and 3(B). In the thermocompression bonding step, a sheet (thermocompression-bonded sheet, first sheet) 17 is thermocompression-bonded to the front surface 11a of the workpiece 11.

[0024] 3(A) is a perspective view showing the workpiece 11 on which the sheet 17 is placed. The sheet 17 is a sheet that can be thermocompressed to the workpiece 11. Specifically, the sheet 17 is made of a thermoplastic resin having a melting point lower than that of the workpiece 11, and does not contain an adhesive (glue layer).

[0025] For example, an olefin-based sheet, a styrene-based sheet, a polyester-based sheet, etc. can be used as the sheet 17. Examples of the olefin-based sheet include a polyethylene sheet and a polypropylene sheet. Examples of the styrene-based sheet include a polystyrene sheet. Examples of the polyester-based sheet include a polyethylene terephthalate sheet and a polyethylene naphthalate sheet.

[0026] The shape and size of the sheet 17 are set so that the sheet 17 can cover the entire surface side (surface 11a side) of the workpiece 11 to which the sheet 17 is fixed. For example, the sheet 17 is formed in a circular shape, and the diameter of the sheet 17 is equal to or greater than the diameter of the workpiece 11. The sheet 17 is then arranged so as to cover the entire surface 11a side of the workpiece 11. In this way, the multiple devices 15 are covered and protected by the sheet 17.

[0027] 3(B) is a perspective view showing the workpiece 11 to which the sheet 17 is thermocompression bonded. The sheet 17, which is arranged on the front surface 11a side of the workpiece 11, is heated and thermocompression bonded to the workpiece 11. For example, the sheet 17 is heated and pressurized by the heating unit 2.

[0028] The heating unit 2 includes a chuck table (not shown) that supports the workpiece 11, and a heatable roller (heat roller) 4. The roller 4 is formed in a cylindrical shape with a height equal to or greater than the diameter of the workpiece 11, and includes a heat source inside. When the workpiece 11 is held by the chuck table and the roller 4 heated to a predetermined temperature is brought into contact with the sheet 17 and rolled over the sheet 17, the sheet 17 is pressed against the surface 11a of the workpiece 11 while being heated.

[0029] Sheet 17 is heated so that the temperature of sheet 17 is equal to or higher than the softening point of sheet 17 and equal to or lower than the melting point of sheet 17. However, sheet 17 may not have a clear softening point. In this case, sheet 17 is heated so that the temperature of sheet 17 is equal to or higher than a temperature that is a predetermined temperature (for example, 20°C) lower than the melting point of sheet 17 and equal to or lower than the melting point of sheet 17.

[0030] For example, if sheet 17 is a polyethylene sheet, the heating temperature can be set to 120°C or higher and 140°C or lower, and if sheet 17 is a polypropylene sheet, the heating temperature can be set to 160°C or higher and 180°C or lower. If sheet 17 is a polystyrene sheet, the heating temperature can be set to 220°C or higher and 240°C or lower. Furthermore, if sheet 17 is a polyethylene terephthalate sheet, the heating temperature can be set to 250°C or higher and 270°C or lower, and if sheet 17 is a polyethylene naphthalate sheet, the heating temperature can be set to 160°C or higher and 180°C or lower.

[0031] When sheet 17 is pressed against workpiece 11 while being heated, sheet 17 softens and deforms to conform to the shape of surface 11a of workpiece 11, and adheres closely to surface 11a of workpiece 11. As a result, sheet 17 is thermocompression bonded to surface 11a of workpiece 11 and fixed thereto.

[0032] There is no limitation on the method of heating and pressing the sheet 17. For example, a plate-shaped pressing member (plate) equipped with an internal heat source can be used instead of the roller 4. In this case, by pressing the pressing member heated to a predetermined temperature against the sheet 17, the sheet 17 is pressed against the front surface 11a of the workpiece 11 while being heated.

[0033] Next, a support member arranging step (step S2) is performed in which a support member is arranged on the rear surface 11b side of the workpiece 11. Fig. 4(A) is a perspective view showing the workpiece 11 and the support member 19 in the support member arranging step.

[0034] The support member 19 is a member that supports the back surface 11b side of the workpiece 11, and includes, for example, an annular frame 21 and a circular tape 23. The frame 21 is made of a metal such as SUS (stainless steel), and has a cylindrical opening 21a at the center of the frame 21 that penetrates the frame 21 in the thickness direction. The diameter of the opening 21a is larger than the diameter of the workpiece 11.

[0035] The tape 23 includes a circular film-like substrate and an adhesive (glue layer) provided on the substrate. For example, the substrate is made of a resin such as polyolefin, polyvinyl chloride, or polyethylene terephthalate. The adhesive is made of an epoxy-based, acrylic-based, or rubber-based adhesive. The adhesive may be an ultraviolet-curable resin that hardens when exposed to ultraviolet light.

[0036] With the workpiece 11 placed inside the opening 21a of the frame 21, the center of the tape 23 is attached to the back surface 11b of the workpiece 11, and the outer periphery of the tape 23 is attached to the frame 21. In this way, the workpiece 11 is supported by the frame 21 via the tape 23.

[0037] 4(B) is a perspective view showing the workpiece 11 and the support member 19 after the support member arranging step. When the workpiece 11 is processed by the processing device, the workpiece 11 is supported by the support member 19 for ease of handling (transporting, holding, etc.) the workpiece 11. However, if the workpiece 11 can be handled independently without being supported by the support member 19, the support member arranging step may be omitted.

[0038] Next, a processing step (step S3) is performed in which the workpiece 11 is processed together with the sheet 17. For example, in the processing step, the workpiece 11 is divided by cutting the workpiece 11 along the streets 13 (see FIG. 1, etc.) using a cutting device.

[0039] Fig. 5 is a perspective view showing the cutting device 10. In Fig. 5, the X1 axis direction (processing feed direction, first horizontal direction) and the Y1 axis direction (indexing feed direction, second horizontal direction) are perpendicular to each other. The Z1 axis direction (vertical direction, up-down direction, height direction) is perpendicular to the X1 axis direction and the Y1 axis direction.

[0040] The cutting device 10 includes a chuck table (holding table) 12 that holds the workpiece 11. The upper surface of the chuck table 12 is a flat surface that is roughly parallel to a horizontal plane (X1Y1 plane) and forms a circular holding surface that holds the workpiece 11. The holding surface of the chuck table 12 is connected to a suction source (not shown) such as an ejector via a flow path (not shown), a valve (not shown), and the like formed inside the chuck table 12.

[0041] A ball screw type movement mechanism (not shown) and a rotation drive source (not shown) such as a motor are connected to the chuck table 12. The movement mechanism moves the chuck table 12 along the X1 axis direction. The rotation drive source rotates the chuck table 12 around a rotation axis that is roughly parallel to the Z1 axis direction.

[0042] The cutting device 10 also includes a cutting unit 14 disposed above the chuck table 12. The cutting unit 14 includes a cylindrical housing 16, and the housing 16 accommodates a columnar spindle (not shown) disposed along the Y1-axis direction. A tip end (one end) of the spindle is exposed to the outside of the housing 16, and a base end (other end) of the spindle is connected to a rotational drive source (not shown), such as a motor.

[0043] An annular cutting blade 18 is attached to the tip of the spindle. The cutting blade 18 rotates at a predetermined rotational speed around a rotation axis that is roughly parallel to the Y1-axis direction by power transmitted from a rotary drive source via the spindle.

[0044] For example, a hub-type cutting blade (hub blade) is used as the cutting blade 18. The hub blade has an annular base made of metal or the like and an annular cutting edge formed along the outer periphery of the base. The cutting edge of the hub blade is made of an electroformed grinding stone containing abrasive grains made of diamond or the like and a binder such as a nickel-plated layer that secures the abrasive grains in place. A washer-type cutting blade (washer blade) can also be used as the cutting blade 18. A washer blade is made up of only an annular cutting edge that contains abrasive grains made of diamond or the like and a binder made of metal, ceramics, resin, or the like that secures the abrasive grains in place.

[0045] The cutting blade 18 attached to the cutting unit 14 is covered by a blade cover 20 fixed to the tip of the housing 16. The blade cover 20 includes a pair of connectors 22 connected to a tube (not shown) that supplies a liquid (cutting fluid) such as pure water, and a pair of nozzles 24 connected to the pair of connectors 22. The pair of nozzles 24 are arranged on both sides (front and back sides) of the lower end of the cutting blade 18 so as to sandwich the cutting blade 18 therebetween. Each of the pair of nozzles 24 is formed with a supply port (not shown) that opens toward the cutting blade 18.

[0046] When cutting fluid is supplied to the pair of connecting portions 22, the cutting fluid flows into the pair of nozzles 24, and is supplied from the supply ports of the nozzles 24 toward both surfaces (front and back surfaces) of the cutting blade 18. This cutting fluid cools the workpiece 11 and the cutting blade 18, and also washes away chips (cutting chips) generated by the cutting process.

[0047] A ball screw type movement mechanism (not shown) that moves the cutting unit 14 along the Y1-axis direction and the Z1-axis direction is connected to the cutting unit 14. The movement mechanism adjusts the position of the cutting blade 18 in the indexing feed direction, the cutting depth of the cutting blade 18 into the workpiece 11, etc.

[0048] When cutting the workpiece 11 with the cutting device 10, the workpiece 11 is first placed on the chuck table 12 via the tape 23. At this time, the workpiece 11 is placed so that the front surface 11a (sheet 17 side) faces upward and the back surface 11b (tape 23 side) faces the holding surface of the chuck table 12. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface of the chuck table 12, the workpiece 11 is suction-held by the chuck table 12 via the tape 23.

[0049] Next, the chuck table 12 is rotated to align the length direction of a predetermined street 13 (see FIG. 1) with the X1-axis direction. The position of the cutting unit 14 in the Y1-axis direction is also adjusted so that the cutting blade 18 is positioned on an extension of the predetermined street 13. Furthermore, the height (position in the Z1-axis direction) of the cutting unit 14 is adjusted so that the lower end of the cutting blade 18 is positioned below the back surface 11b of the workpiece 11 (the upper surface of the tape 23).

[0050] Then, while rotating the cutting blade 18, the chuck table 12 is moved along the X1 axis direction. As a result, the chuck table 12 and the cutting blade 18 move relatively along the X1 axis direction, and the cutting blade 18 cuts into the workpiece 11 along the streets 13. As a result, the workpiece 11 and the sheet 17 are cut and divided along the streets 13. Furthermore, in the areas of the workpiece 11 and the sheet 17 cut by the cutting blade 18, grooves (cut grooves) 25 are formed along the streets 13, extending from the upper surface of the sheet 17 to the back surface 11b of the workpiece 11.

[0051] Thereafter, by repeating the same procedure, the workpiece 11 and the sheet 17 are cut along all of the streets 13, forming grooves 25. As a result, the workpiece 11 is divided into a plurality of device chips, each of which has a device 15 (see FIG. 1, etc.) and to which an individual piece of the sheet 17 is attached.

[0052] When the workpiece 11 is cut with the cutting blade 18, cutting chips are generated in the contact area between the workpiece 11 and the cutting blade 18, and are caught up in the rotation of the cutting blade 18 and scattered. However, because the surface 11a side of the workpiece 11 is covered with the sheet 17, the cutting chips do not adhere to the surface 11a of the workpiece 11 or the device 15. This prevents contamination of the workpiece 11 and the device 15 by the cutting chips.

[0053] In the processing step, the workpiece 11 may be divided along the streets 13 (see FIG. 1, etc.) using a laser processing device. FIG. 6 is a perspective view showing the laser processing device 30. In FIG. 6, the X2-axis direction (processing feed direction, first horizontal direction) and the Y2-axis direction (indexing feed direction, second horizontal direction) are perpendicular to each other. The Z2-axis direction (vertical direction, up-down direction, height direction) is perpendicular to the X2-axis direction and the Y2-axis direction.

[0054] The laser processing device 30 includes a chuck table (holding table) 32 that holds the workpiece 11. The configuration and function of the chuck table 32 are similar to those of the chuck table 12 of the cutting device 10 (see FIG. 5). The chuck table 32 is connected to a ball screw type movement mechanism (not shown) and a rotation drive source (not shown) such as a motor. The movement mechanism moves the chuck table 32 along the X2-axis direction and the Y2-axis direction. The rotation drive source rotates the chuck table 32 around a rotation axis that is generally parallel to the Z2-axis direction.

[0055] The laser processing apparatus 30 also includes a laser irradiation unit 34 that irradiates a laser beam. The laser irradiation unit 34 includes a laser oscillator (not shown) such as a YAG laser, YVO4 laser, or YLF laser, and a laser processing head 36 that is arranged above the chuck table 12. The laser processing head 36 houses an optical system that guides the pulsed laser beam emitted from the laser oscillator to the workpiece 11, and the optical system includes optical elements such as a condenser lens that condenses the laser beam. The workpiece 11 is laser processed by a laser beam 38 irradiated from the laser irradiation unit 34.

[0056] When processing the workpiece 11 with the laser processing device 30, first, the workpiece 11 is placed on the chuck table 32 via the tape 23. At this time, the workpiece 11 is placed so that the front surface 11a (sheet 17 side) faces upward and the back surface 11b (tape 23 side) faces the holding surface of the chuck table 32. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface of the chuck table 32, the workpiece 11 is suction-held by the chuck table 32 via the tape 23.

[0057] Next, the chuck table 32 is rotated to align the length direction of the predetermined street 13 (see FIG. 1) with the X2-axis direction. The position of the chuck table 32 in the Y2-axis direction is also adjusted so that the area irradiated with the laser beam 38 overlaps with an extension of the predetermined street 13. Furthermore, the optical system of the laser irradiation unit 34 is adjusted so that the focal point of the laser beam 38 is positioned at the same height as the surface 11a or the inside of the workpiece 11 (position in the Z2-axis direction).

[0058] Then, the chuck table 32 is moved along the X2-axis direction while irradiating the laser beam 38 from the laser processing head 36. As a result, the chuck table 32 and the laser beam 38 move relatively along the X2-axis direction, and the laser beam 38 is irradiated along the street 13 onto the front surface 11a of the workpiece 11.

[0059] The irradiation conditions of the laser beam 38 are set, for example, so that ablation processing is performed on the workpiece 11. Specifically, the wavelength of the laser beam 38 is set so that at least a portion of the laser beam 38 is absorbed by the workpiece 11. In other words, the laser beam 38 is a laser beam that is absorbable by the workpiece 11. Other irradiation conditions of the laser beam 38 are also set appropriately so that ablation processing is appropriately performed on the workpiece 11. For example, when the workpiece 11 is a single crystal silicon wafer, the irradiation conditions of the laser beam 38 can be set as follows: Wavelength: 355nm Average output: 2W Repetition frequency: 200kHz Processing feed rate: 400mm / s

[0060] When the laser beam 38 is irradiated onto the workpiece 11 along the streets 13, the area of ​​the workpiece 11 irradiated with the laser beam 38 (the processed area) is removed by ablation. Furthermore, the area of ​​the sheet 17 that overlaps with the processed area of ​​the workpiece 11 is also broken by irradiation with the laser beam 38, collision with debris generated by the ablation of the workpiece 11, and the like. As a result, the workpiece 11 and the sheet 17 are divided along the streets 13. Furthermore, in the areas of the workpiece 11 and the sheet 17 processed by the laser beam 38, grooves (laser processed grooves) 27 are formed along the streets 13, extending from the upper surface of the sheet 17 to the back surface 11b of the workpiece 11.

[0061] Thereafter, by repeating the same procedure, the laser beam 38 is irradiated along all of the streets 13, forming grooves 27. As a result, the workpiece 11 is divided into a plurality of device chips, each of which has a device 15 (see FIG. 1, etc.) and to which an individual piece of the sheet 17 is attached. If it is difficult to divide the workpiece 11 and the sheet 17 by scanning the laser beam 38 once, the laser beam 38 may be irradiated along each street 13 multiple times.

[0062] When the workpiece 11 is subjected to ablation processing, melted material (debris) of the workpiece 11 is generated and scattered. However, because the surface 11a side of the workpiece 11 is covered by the sheet 17, the debris does not adhere to the surface 11a of the workpiece 11 or the device 15. This prevents the workpiece 11 and the device 15 from being contaminated by the debris.

[0063] In the processing step, the workpiece 11 may be subjected to plasma processing. For example, the workpiece 11 is subjected to plasma etching using a plasma processing device, whereby the workpiece 11 is divided along the streets 13 (see FIG. 1, etc.) (plasma dicing).

[0064] 7 is a partial cross-sectional front view showing a plasma processing apparatus (plasma etching apparatus) 40. The plasma processing apparatus 40 includes a rectangular parallelepiped chamber 42. The chamber 42 includes a bottom wall 42a, an upper wall 42b, a first side wall 42c, a second side wall 42d, a third side wall 42e, and a fourth side wall (not shown). The interior of the chamber 42 corresponds to a processing space 44 where plasma processing is performed.

[0065] An opening 46 is provided in the second side wall 42d for carrying in and out the workpiece 11. A gate (opening / closing door) 48 for opening and closing the opening 46 is provided on the outside of the opening 46. The gate 48 is connected to an opening / closing mechanism 50, which moves the gate 48 in the vertical direction (up and down). For example, the opening / closing mechanism 50 is composed of an air cylinder 52 equipped with a piston rod 54. The air cylinder 52 is fixed to the bottom wall 42a of the chamber 42 via a bracket 56, and the upper end of the piston rod 54 is connected to the gate 48.

[0066] When the gate 48 is lowered by the opening / closing mechanism 50, the opening 46 is exposed. This makes it possible to load the workpiece 11 into the processing space 44 through the opening 46, or to load the workpiece 11 out of the processing space 44 through the opening 46.

[0067] An exhaust port 58 is formed in the bottom wall 42a of the chamber 42, connecting the inside and outside of the chamber 42. An exhaust mechanism 60 for reducing the pressure in the processing space 44 is connected to the exhaust port 58. The exhaust mechanism 60 is configured by, for example, a vacuum pump.

[0068] A lower electrode 62 and an upper electrode 64 are arranged facing each other in the processing space 44. The lower electrode 62 is made of a conductive material and includes a disk-shaped holding portion 66 and a cylindrical support portion 68 that protrudes downward from the center of the lower surface of the holding portion 66.

[0069] The support part 68 is inserted into an opening 70 formed in the bottom wall 42a of the chamber 42. An annular insulating member 72 is disposed between the bottom wall 42a inside the opening 70 and the support part 68, and the chamber 42 and the lower electrode 62 are insulated by the insulating member 72. The lower electrode 62 is also connected to a high-frequency power source 74 outside the chamber 42.

[0070] A recess is formed on the upper surface side of the holding part 66, and a disk-shaped table 76 for holding the workpiece 11 is provided in this recess. The upper surface of the table 76 forms a flat holding surface 76a for holding the workpiece 11. The holding surface 76a is connected to a suction source 80 such as an ejector via a flow path (not shown) formed inside the table 76 and a flow path 78 formed inside the lower electrode 62.

[0071] A cooling flow path 82 is formed inside the holding part 66. One end of the cooling flow path 82 is connected to a coolant circulation mechanism 86 via a coolant introduction path 84 formed in the support part 68. The other end of the cooling flow path 82 is connected to the coolant circulation mechanism 86 via a coolant discharge path 88 formed in the support part 68. When the coolant circulation mechanism 86 is operated, the coolant flows through the coolant introduction path 84, the cooling flow path 82, and the coolant discharge path 88 in this order, thereby cooling the lower electrode 62.

[0072] The upper electrode 64 is made of a conductive material and includes a disk-shaped gas ejection part 90 and a cylindrical support part 92 that protrudes upward from the center of the top surface of the gas ejection part 90. The support part 92 is inserted into an opening 94 formed in the upper wall 42b of the chamber 42. An annular insulating member 96 is disposed between the upper wall 42b and the support part 92 within the opening 94, and the insulating member 96 insulates the chamber 42 from the upper electrode 64. The upper electrode 64 is also connected to a high-frequency power supply 98 outside the chamber 42.

[0073] A support arm 102 connected to a lifting mechanism 100 is attached to the upper end of the support part 92. When the support arm 102 is raised and lowered by the lifting mechanism 100, the upper electrode 64 moves (lifts and lowers) in the vertical direction (up and down direction).

[0074] A plurality of gas outlets 104 are provided on the underside of the gas outlet part 90. The outlets 104 are connected to a first gas supply source 110 and a second gas supply source 112 via a flow path 106 formed inside the gas outlet part 90 and a flow path 108 formed inside the support part 92. The first gas supply source 110 and the second gas supply source 112 can supply gases with different components to the flow path 108.

[0075] Each component of the plasma processing apparatus 40 (opening / closing mechanism 50, exhaust mechanism 60, high-frequency power supply 74, suction source 80, coolant circulation mechanism 86, high-frequency power supply 98, lifting mechanism 100, first gas supply source 110, second gas supply source 112, etc.) is connected to a control unit (control unit, control device) 114 that controls the plasma processing apparatus 40. The control unit 114 generates control signals that control the operation of each component of the plasma processing apparatus 40.

[0076] For example, the control unit 114 is configured by a computer and includes an arithmetic unit that performs calculations necessary for the operation of the plasma processing apparatus 40, and a storage unit that stores various information (data, programs, etc.) used for the operation of the plasma processing apparatus 40. The arithmetic unit includes a processor such as a CPU (Central Processing Unit). The storage unit includes memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory).

[0077] When plasma etching is performed on the workpiece 11 using the plasma processing device 40, first, the gate 48 of the plasma processing device 40 is lowered by the opening / closing mechanism 50 to expose the opening 46. Then, the workpiece 11 is carried into the processing space 44 of the chamber 42 through the opening 46 by a transport mechanism (not shown), and placed on the table 76. Note that when carrying the workpiece 11 in, it is preferable to raise the upper electrode 64 by the lifting mechanism 100 to widen the gap between the lower electrode 62 and the upper electrode 64.

[0078] Next, negative pressure from suction source 80 is applied to holding surface 76a of table 76, and workpiece 11 is held by suction on table 76. Also, opening / closing mechanism 50 raises gate 48 to close opening 46 and seal processing space 44. Furthermore, lifting mechanism 100 adjusts the height of upper electrode 64 so that upper electrode 64 and lower electrode 62 are in a predetermined positional relationship suitable for plasma etching. Then, exhaust mechanism 60 is operated to reduce pressure in processing space 44 (for example, 50 Pa or more and 300 Pa or less).

[0079] If it becomes difficult to hold the workpiece 11 on the table 76 due to the negative pressure of the suction source 80 when the processing space 44 is depressurized, the workpiece 11 is held on the table 76 by an electric force (typically, electrostatic attraction). For example, a plurality of electrodes are embedded inside the table 76. By applying a predetermined voltage to these electrodes, a Coulomb force is exerted between the table 76 and the workpiece 11, and the workpiece 11 can be attracted to the table 76. In other words, the table 76 functions as an electrostatic chuck table.

[0080] Then, an etching gas (etching gas) is supplied between the lower electrode 62 and the upper electrode 64 from the first gas supply source 110 or the second gas supply source 112 via the flow path 108, the flow path 106, and the plurality of nozzles 104. A predetermined high-frequency power (for example, 1000 W or more and 3000 W or less) is applied to the lower electrode 62 and the upper electrode 64. As a result, the etching gas present between the lower electrode 62 and the upper electrode 64 becomes a plasma state containing ions and radicals. The gas in the plasma state is then supplied to the workpiece 11, and the workpiece 11 is subjected to plasma etching.

[0081] 8 is a cross-sectional view showing a portion of workpiece 11 to be plasma etched. When plasma etching is performed on workpiece 11, a mask 29 is formed on sheet 17. For example, mask 29 is formed by applying a resist made of a photosensitive resin onto sheet 17 and patterning the resist so that the areas of sheet 17 that overlap with streets 13 are exposed.

[0082] However, there are no limitations on the material and method of forming mask 29. For example, mask 29 made of water-soluble resin may be formed by applying a film made of water-soluble resin such as PVA (polyvinyl alcohol), PEG (polyethylene glycol), PEO (polyethylene oxide), or PVP (polyvinylpyrrolidone) onto sheet 17, and then patterning the film by irradiating it with a laser beam or the like.

[0083] The workpiece 11 is placed on the table 76 so that the front surface 11a (the sheet 17 side) faces upward and the back surface 11b (the tape 23 side) faces the holding surface 76a. Then, a plasma gas (etching gas) 116 is supplied to the sheet 17 and the workpiece 11 through the openings in the mask 29. As a result, the areas of the workpiece 11 and the sheet 17 that overlap with the streets 13 are removed by etching, and grooves 31 that extend from the upper surface of the sheet 17 to the back surface 11b of the workpiece 11 are formed along the streets 13. As a result, the workpiece 11 and the sheet 17 are divided along the streets 13.

[0084] 7 can etch the workpiece 11 and the sheet 17 using etching gases with different components. For example, the plasma processing apparatus 40 converts gas supplied from the first gas supply source 110 into plasma for use in etching the sheet 17, and converts gas supplied from the second gas supply source 112 into plasma for use in etching the workpiece 11.

[0085] When plasma etching is performed on the workpiece 11 and the sheet 17, some of the components of the etching gas may adhere and deposit on the workpiece 11. However, because the surface 11a side of the workpiece 11 is covered by the sheet 17, the deposits do not adhere to the surface 11a of the workpiece 11 or the device 15. This prevents contamination of the workpiece 11 and the device 15 by the deposits.

[0086] After plasma etching of the workpiece 11 and the sheet 17, a process for removing the mask 29 is carried out. At this time, since the front surface 11a side of the workpiece 11 is covered with the sheet 17, it is possible to prevent chemicals or the like used for removing the mask 29 from adhering to the front surface 11a of the workpiece 11 or the device 15.

[0087] As described above, in the processing step, the workpiece 11 is processed together with the sheet 17 by cutting the workpiece 11 and the sheet 17 with the cutting blade 18 (see FIG. 5), or by irradiating the workpiece 11 and the sheet 17 with the laser beam 38 (see FIG. 6), or by supplying the workpiece 11 and the sheet 17 with the plasma gas 116 (see FIG. 8). However, the type and content of processing performed on the workpiece 11 and the sheet 17 in the processing step are not limited to those described above.

[0088] Next, an integration step (step S4) is performed to integrate the processed sheets 17. In the peeling step, the sheets 17, which have been divided into multiple pieces, are heated and melted to connect the multiple pieces and integrate the sheets 17.

[0089] 9(A) is a perspective view showing the workpiece 11 and the sheet 17 in the integration step. For example, the sheet 17 is heated by a heating unit 120. The heating unit 120 includes a chuck table (not shown) that supports the workpiece 11 and a heat source 122 that heats the sheet 17. The heating unit 120 may be provided in a processing device that processes the workpiece 11 in the processing step, or may be installed independently of the processing device.

[0090] For example, the heat source 122 includes a heat generating mechanism such as an electric heating wire and a blowing mechanism such as a fan, and heats a gas such as air and sprays it as hot air 124. The workpiece 11 is held on a chuck table, and the hot air 124 is blown from the heat source 122 onto the sheet 17, thereby heating the sheet 17.

[0091] Sheet 17 is heated until the temperature of sheet 17 reaches the melting point of sheet 17. As a result, the individual pieces of sheet 17 melt and connect to each other, and grooves 25 formed in sheet 17 disappear. As a result, sheet 17 is integrated into a single circular member.

[0092] 9(B) is a perspective view showing the workpiece 11 and the sheet 17 after the integration step. When the integration step is performed, the sheet 17 is integrated and returns to the same state as before processing (see FIG. 4(B)). There is no limitation on the method of heating the sheet 17. For example, an infrared lamp may be used as the heat source 122, and the sheet 17 may be heated by irradiating the sheet 17 with infrared rays from the infrared lamp.

[0093] Next, a peeling step (step S5) is performed in which sheet 17 is peeled off from workpiece 11. In the peeling step, a second sheet made of a thermoplastic resin is thermocompression bonded to sheet 17, and then sheet 17 is peeled off from workpiece 11 by moving the second sheet. To peel off sheet 17, for example, a peeling device is used.

[0094] 10 is a perspective view showing the peeling device 130. In FIG. 10, the X3 axis direction (first horizontal direction) and the Y3 axis direction (second horizontal direction) are perpendicular to each other. The Z3 axis direction (vertical direction, up-down direction, height direction) is perpendicular to the X3 axis direction and the Y3 axis direction. The peeling device 130 may be provided in a processing device that processes the workpiece 11 in the processing step, or may be installed independently of the processing device.

[0095] The peeling device 130 includes a chuck table (holding table) 132 that holds the workpiece 11, and a peeling unit 134 that peels the sheet 17 from the workpiece 11. The peeling device 130 holds the workpiece 11 to which the sheet 17 is fixed by the chuck table 132, thermocompresses a sheet (peeling sheet, second sheet) 33 made of a thermoplastic resin to the sheet 17, and peels the sheet 17 and the sheet 33 from the workpiece 11.

[0096] The upper surface of the chuck table 132 is a flat surface that is roughly parallel to the horizontal plane (X3Y3 plane) and forms a circular holding surface that holds the workpiece 11. The holding surface of the chuck table 132 is connected to a suction source (not shown) such as an ejector via a flow path (not shown), a valve (not shown), and the like formed inside the chuck table 132.

[0097] The peeling unit 134 includes a holding mechanism 136 that holds the sheet 33. For example, the holding mechanism 136 includes an air cylinder 138 with a piston rod 140, and the air cylinder 138 moves the piston rod 140 up and down along the Z3 axis direction.

[0098] A rectangular parallelepiped support member 142 is fixed to the lower end of the piston rod 140. A gripping mechanism 144 that grips the sheet 33 is attached to the support member 142. The gripping mechanism 144 includes a flat side wall 144a and a pair of flat gripping members 144b and 144c that protrude from the side surface of the side wall 144a along the Y3 axis direction.

[0099] The gripping members 144b and 144c are disposed generally parallel to each other along the Y3-axis direction. The gripping member 144b is connected to the lower end of the side wall 144a, and the gripping member 144c is disposed above the gripping member 144b so as to overlap the gripping member 144b. A moving mechanism (not shown) is connected to the gripping member 144c, and the moving mechanism slides the gripping member 144c in the Z3-axis direction along the side wall 144a. With the end of the sheet 33 inserted between the pair of gripping members 144b and 144c, the gripping member 144c is lowered and brought close to the gripping member 144b, whereby the end of the sheet 33 is gripped by the gripping members 144b and 144c.

[0100] Sheet 33 is a sheet made of a thermoplastic resin that can be thermocompressed to sheet 17, and does not contain an adhesive (glue layer). Examples of materials for sheet 33 are the same as those for sheet 17. That is, an olefin-based sheet, a styrene-based sheet, a polyester-based sheet, or the like can be used as sheet 33. For example, the material for sheet 17 and the material for sheet 33 may be the same. Alternatively, the material for sheet 17 and the material for sheet 33 may be different, and the melting point of sheet 33 may be lower than the melting point of sheet 17.

[0101] For example, the sheet 33 is formed in a strip shape and fixed to a roller (not shown) and wound up. The leading end of the sheet 33 fed from the roller is gripped by a pair of gripping members 144b and 144c.

[0102] The peeling unit 134 also includes a heating mechanism 146 that heats the sheet 33. For example, the heating mechanism 146 has an air cylinder 148 equipped with a piston rod 150, and the air cylinder 148 raises and lowers the piston rod 150 along the Z3 axis direction. The air cylinder 148 is disposed adjacent to the air cylinder 138 in the Y3 axis direction.

[0103] A heating element (heating plate) 152 is fixed to the lower end of the piston rod 140. For example, the heating element 152 is a flat metal element, and is disposed approximately parallel to the X3 axis direction and the Z3 axis direction. A heat source such as an electric heating wire is provided inside the heating element 152, and the heating element 152 is heated to a predetermined temperature by the heat generated by the heat source. When the sheet 33 is held by the holding mechanism 136, a portion of the sheet 33 is positioned so as to overlap with the heating element 152.

[0104] Furthermore, the peeling unit 134 includes a cutting mechanism 154 that cuts the sheet 33. For example, the cutting mechanism 154 includes an air cylinder 156 with a piston rod 158, and the air cylinder 156 moves the piston rod 158 up and down along the Z3 axis direction.

[0105] A cutter (blade) 160 is attached to the lower end of the piston rod 158. The cutter 160 is a disk-shaped member made of metal or the like, and is disposed generally parallel to the X3-axis direction and the Z3-axis direction. A rotational drive source (not shown), such as a motor, is connected to the cutter 160, and the rotational drive source rotates the cutter 160 around a rotation axis generally parallel to the Y3-axis direction.

[0106] The cutting mechanism 154 also includes a support base 162 that supports the sheet 33. For example, the support base 162 is a rectangular parallelepiped member made of metal, resin, or the like, and is disposed below the sheet 33. A groove 162a is provided on the upper surface of the support base 162 along the Y3 axis direction. The width of the groove 162a is wider than the width of the cutter 160, and the lower end of the cutter 160 can be inserted into the groove 162a.

[0107] A ball screw type movement mechanism (not shown) provided in the peeling device 130 is connected to the peeling unit 134. The movement mechanism moves the holding mechanism 136 and the heating mechanism 146 along the Y3 axis direction. The movement mechanism also moves the cutting mechanism 154 along the X3 axis direction and the Y3 axis direction independently of the holding mechanism 136 and the heating mechanism 146.

[0108] When peeling the sheet 17 from the workpiece 11 using the peeling device 130, first, the workpiece 11 is placed on the holding surface of the chuck table 132 via the tape 23. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface of the chuck table 132, the workpiece 11 is sucked and held by the chuck table 132 via the tape 23.

[0109] Next, the holding mechanism 136 and the heating mechanism 146 are moved to position the sheet 33 and the heating member 152 above the workpiece 11. One end of the sheet 33 is held by the holding mechanism 144, and the other end of the sheet 33 is taken up on a roller (not shown). The sheet 33 is positioned so as to overlap the sheet 17 fixed to the workpiece 11, with the sheet 33 stretched between the holding mechanism 144 and the roller. The heating member 152 is positioned so as to overlap the sheet 17 and the sheet 33.

[0110] Next, while heating the heating element 152 to a predetermined temperature, the piston rod 150 is lowered. As a result, the heating element 152 comes into contact with the sheet 33 located directly below, and the heating element 152 is heated. The sheet 33 is also heated. The heating element 152 also presses the sheet 33 downward, and presses it against the sheet 17 fixed to the workpiece 11. As a result, the sheet 33 is heated and pressurized, and is thermocompression-bonded to the sheet 17.

[0111] The heating temperature of sheet 33 is appropriately set so that sheet 33 is thermocompression bonded to sheet 17. A specific example of the heating temperature of sheet 33 is the same as the heating temperature of sheet 17 in the thermocompression bonding step (see FIG. 3(B)).

[0112] Next, the positions of the holding mechanism 136 and the support base 162 are adjusted so that the sheet 33 is supported on the upper surface side of the support base 162. Furthermore, the position of the cutting mechanism 154 is adjusted so that the cutter 160 overlaps with the groove 162a of the support base 162. Then, the piston rod 158 is lowered, and the lower end of the cutter 160 is inserted into the groove 162a of the support base 162. Thereafter, the cutter 160 is rotated while the cutting mechanism 154 is moved along the X3 axis direction, causing the cutter 160 to cut into the sheet 33. This cuts the sheet 33, and the tip side (the gripping mechanism 144 side) of the sheet 33 is separated.

[0113] 11(A) is a partial cross-sectional front view showing sheet 17 to which sheet 33 has been thermocompression-bonded. When sheet 33 is heated by heating member 152 (see FIG. 10) and pressed against sheet 17, sheet 33 and area 17a of sheet 17 that comes into contact with sheet 33 are heated, and sheet 33 is thermocompression-bonded to area 17a of sheet 17. As a result, sheet 17 and sheet 33 are joined, and sheet 33 firmly adheres to sheet 17.

[0114] 11(B) is a partial cross-sectional front view showing sheet 17 being peeled off from workpiece 11. After sheet 33 is thermocompression bonded to one end of sheet 17, gripping mechanism 144 is moved toward the other end of sheet 17, whereby sheet 33 is pulled by gripping mechanism 144, and one end of sheet 17 moves toward the other end of sheet 17 following sheet 33. As a result, sheet 17 is peeled off from workpiece 11.

[0115] However, there is no limitation on the direction in which the sheet 33 is pulled. For example, the sheet 17 may be peeled off by pulling the sheet 33 upward by raising the gripping mechanism 144 along the Z3 axis direction.

[0116] By the above-mentioned peeling step, the sheet 17 is peeled off from the workpiece 11. Since the sheet 17 is made of a thermoplastic resin that does not contain an adhesive (glue layer), no adhesive remains on the surface 11a of the workpiece 11 after the sheet 17 is peeled off. This prevents contamination of the workpiece 11 and the device 15 (see FIG. 1) by adhesive residue.

[0117] Furthermore, in the peeling step, sheet 17 is peeled off from workpiece 11 using sheet 33 fixed to sheet 17 by thermocompression bonding. This makes it possible to make the adhesion between sheet 17 and sheet 33 equal to or greater than the adhesion between workpiece 11 and sheet 17, even if sheet 17 is firmly adhered to workpiece 11 by thermocompression bonding, and prevents sheet 33 from separating from sheet 17 during peeling of sheet 17.

[0118] As described above, in the method for processing a workpiece according to this embodiment, after sheet 33 is thermocompression bonded to processed sheet 17, sheet 17 is peeled off from workpiece 11 by moving sheet 33. This allows sheet 17 to be peeled off while the adhesion between sheet 17 and sheet 33 is high, preventing separation of sheet 17 and sheet 33 during peeling. As a result, sheet 17, which is firmly fixed to workpiece 11 by thermocompression bonding, can be reliably peeled off.

[0119] In the above embodiment, an example has been described in which the sheet 17 is peeled off from the workpiece 11 after the integration step (see FIGS. 9(A) and 9(B)) of integrating the processed sheet 17 is performed, but the integration step can also be omitted. In this case, a release sheet is fixed to the entire processed sheet 17, so that the entire sheet 17 is peeled off from the workpiece 11. Another example of the peeling step will be described with reference to FIGS. 12(A) and 12(B).

[0120] 12(A) is a perspective view showing sheet 17 to which sheet (release sheet, second sheet) 35 is thermocompression bonded. After the processing step (see FIGS. 5 to 8) is performed, sheet 35 made of a plastic resin is thermocompression bonded to processed sheet 17.

[0121] Sheet 35 is a sheet made of a thermoplastic resin that can be thermocompressed to sheet 17, and does not contain an adhesive (glue layer). Examples of materials for sheet 35 are the same as those for sheet 17. That is, an olefin-based sheet, a styrene-based sheet, a polyester-based sheet, or the like can be used as sheet 35. For example, the material for sheet 17 and the material for sheet 35 may be the same. Alternatively, the material for sheet 17 and the material for sheet 35 may be different, and the melting point of sheet 35 may be lower than the melting point of sheet 17.

[0122] The shape and size of the sheet 35 are set so that the entire sheet 17 can be covered with the sheet 35. For example, the sheet 35 is formed in a circular shape, and the diameter of the sheet 35 is equal to or greater than the diameter of the sheet 17. However, there are no limitations on the shape of the sheet 35. For example, the sheet 35 may be formed in a rectangular shape whose length and width are equal to or greater than the diameter of the sheet 17.

[0123] In the peeling step, the sheet 35 is thermocompression-bonded to the sheet 17, which has been divided into a plurality of pieces. Specifically, the sheet 35 is first placed on the front surface 11a of the workpiece 11 so as to cover all of the pieces of the sheet 17. Next, the sheet 35 is pressed against the sheet 17 while being heated. For example, the sheet 35 is heated and pressurized by the heating unit 2 (see FIG. 3(B)) described above. As a result, the sheet 35 softens and adheres closely to the sheet 17, and the sheet 35 is thermocompression-bonded to the sheet 17.

[0124] The heating temperature of sheet 35 is appropriately set so that sheet 35 is thermocompression bonded to sheet 17. A specific example of the heating temperature of sheet 35 is the same as the heating temperature of sheet 17 in the thermocompression bonding step (see FIGS. 3(A) and 3(B)).

[0125] 12(B) is a perspective view showing sheet 17 being peeled off from workpiece 11. After sheet 35 is thermocompression bonded to sheet 17, for example, an end of sheet 35 is gripped and moved in a direction away from workpiece 11. As a result, sheet 17 is peeled off from workpiece 11 following sheet 35.

[0126] In addition, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the object of the present invention. [Explanation of symbols]

[0127] 11 Workpiece 11a Surface (first side) 11b Back side (2nd side) 13th Street (Planned division line) 15 devices 17 Sheet (thermocompression sheet, first sheet) 17a area 19 Support member 21 frames 21a opening 23 Tape 25 groove (cutting groove) 27 grooves (laser processed grooves) 29 Mask 31 Groove 33 Sheet (Removal sheet, 2nd sheet) 35 sheets (peel-off sheet, second sheet) 2 heating units 4 Roller (heat roller) 10 Cutting equipment 12 Chuck table (holding table) 14 Cutting unit 16 Housing 18 Cutting Blade 20 Blade Cover 22 Connection 24 nozzles 30 Laser processing equipment 32 Chuck table (holding table) 34 Laser irradiation unit 36 Laser processing head 38 Laser Beam 40 Plasma processing equipment (plasma etching equipment) 42 Chambers 42a bottom wall 42b Upper wall 42c 1st side wall 42d Second side wall 42e 3rd side wall 44 Processing Space 46 Aperture 48 Gate (opening door) 50 Opening and closing mechanism 52 Air cylinder 54 Piston rod 56 Bracket 58 Exhaust port 60 Exhaust mechanism 62 Lower electrode 64 Upper electrode 66 Holding part 68 Support part 70 aperture 72 Insulating material 74 High frequency power supply 76 tables 76a Holding surface 78 Flow path 80 Suction source 82 Cooling Channel 84 Refrigerant introduction path 86 Refrigerant circulation mechanism 88 Refrigerant discharge path 90 Gas outlet 92 Support part 94 Aperture 96 Insulating materials 98 High frequency power supply 100 Lifting mechanism 102 support arm 104 spout 106 Flow path 108 Channel 110 First Gas Supply Source 112 Second Gas Supply Source 114 Control unit 116 Gas (Etching Gas) 120 Heating Unit 122 Heat source 124 Hot air 130 Peeling device 132 Chuck table (holding table) 134 Peeling Unit 136 Retention mechanism 138 Air Cylinder 140 Piston rod 142 Support member 144 Gripping mechanism 144a side wall 144b, 144c gripping member 146 Heating mechanism 148 Air Cylinder 150 piston rod 152 heating element (heating plate) 154 Cutting mechanism 156 Air cylinder 158 Piston rod 160 Cutter 162 Support stand 162a Groove

Claims

1. A method for processing a workpiece, comprising: a thermocompression bonding step of placing a first sheet made of a thermoplastic resin on the surface side of the workpiece and heating the first sheet to thermocompression bond the first sheet to the surface side of the workpiece; a processing step of processing the workpiece together with the first sheet; a peeling step of placing a second sheet made of a thermoplastic resin on the processed first sheet and heating the second sheet to thermocompression bond the second sheet to the first sheet, and then moving the second sheet to peel the first sheet from the workpiece, The second sheet is made of the same material as the first sheet or has a lower melting point than the first sheet.

2. A method for processing a workpiece as described in claim 1, characterized in that in the processing step, the workpiece is processed together with the first sheet by cutting a cutting blade into the workpiece and the first sheet, or by irradiating the workpiece and the first sheet with a laser beam, or by supplying a plasma state gas to the workpiece and the first sheet.

3. 3. The method for processing a workpiece according to claim 1, further comprising a support member arranging step of arranging a support member on the back surface side of the workpiece before the processing step.

4. A method for processing a workpiece as described in any one of claims 1 to 3, further comprising an integration step of integrating the processed first sheet by heating and melting the processed first sheet before the peeling step.

5. 5. The method for processing a workpiece according to claim 1, wherein a device is formed on the surface side of the workpiece.

6. A method for processing a workpiece described in any one of claims 1 to 5, characterized in that the first sheet and the second sheet do not contain an adhesive.

7. A method for processing a workpiece described in any one of claims 1 to 6, characterized in that in the peeling step, the second sheet covers the entire first sheet.

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