Method and apparatus for processing a workpiece

Abstract

The present invention provides a method for processing a workpiece that can properly protect the protective member near the edge of a workpiece whose back surface is protected by a protective member, thereby preventing damage to the protective member. [Solution] In the protective film formation process, a coating agent (WSR) is supplied to the first surface (61) side of the workpiece (60) of the work unit (50) to form a protective film (PM) made of the coating agent on the first surface of the workpiece and the protective members (70, 80). At least a portion of the thickness (Y) of the protective film formed on the protective members in the protective film formation process is greater than the thickness (X) of the protective film formed on the first surface of the workpiece.

Description

Technical Field

[0005] , , ,

[0001] The present invention relates to a method and an apparatus for processing a workpiece, and more particularly to a method and an apparatus for processing a workpiece, which include a step of supplying a coating agent to a workpiece unit in which a protective member and a workpiece are joined, and a step of processing the workpiece unit.

Background Art

[0002] When a wafer having a division planned line set on its front surface and a protective member such as a tape or a support substrate provided on its back surface is held by holding means so that the front surface is exposed and processing (for example, cutting, grinding, laser processing, etc.) is performed from the front surface, a liquid resin is coated on the front surface of the wafer to prevent the adhesion of processing by-products and processing accessories (for example, processing chips, melt (debris), etc.) generated during the processing to the front surface.

[0003] For example, Patent Document 1 describes a laser processing method in which a workpiece is processed by irradiating it with a laser beam. This laser processing method includes a protective film coating step of coating a protective film on the processing surface of the workpiece, a laser beam irradiation step of irradiating the workpiece with a laser beam through the protective film, and a protective film removal step of removing the protective film after the laser beam irradiation step.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, according to the present inventor's diligent research, in the prior art including Patent Document 1, when machining is performed up to the edge of the workpiece (boundary with the protective member) or slightly beyond the edge (overrun region) in a work unit in which a protective member and a workpiece are joined, there is a risk that defects or adverse effects will occur in the protective member due to the machining.

[0006] The object of the present invention is to provide a method and apparatus for processing a workpiece that can appropriately protect the protective member near the edge of a workpiece whose back surface is protected by a protective member, and prevent damage to the protective member. [Means for solving the problem]

[0007] A method for processing a workpiece according to one aspect of the present invention comprises: a preparation step of preparing a work unit in which a protective member having a region exposed from the workpiece is fixed to the second surface of a workpiece having a first surface and a second surface opposite to the first surface; a protective film forming step of supplying a coating agent to the first surface of the workpiece on the work unit to form a protective film made of the coating agent on the first surface of the workpiece and the protective member; and a processing step of processing the work unit on which the protective film has been formed from the first surface of the workpiece, wherein the thickness of at least a portion of the protective film formed on the protective member in the protective film forming step is greater than the thickness of the protective film formed on the first surface of the workpiece.

[0008] The protective film formation step may include a workpiece protection step of forming the protective film on the first surface of the workpiece, and a protective member protection step of forming the protective film in the region of the protective member of the work unit that is in contact with the outer edge of the workpiece.

[0009] In the protective member protection step, the supply unit that supplies the coating agent and the work unit may be moved relative to each other to supply the coating agent along the workpiece.

[0010] The workpiece may have a circular outer shape in which a portion of its outer circumference is cut out when viewed from above.

[0011] The processing step may include a laser processing step in which a laser beam is irradiated onto the workpiece.

[0012] The protective film formation step includes a protective member protection step in which the protective film is formed in a region of the protective member of the work unit that is in contact with the outer edge of the workpiece, and the laser processing step includes an overrun step in which the laser beam is irradiated to a region of the workpiece in which the protective member is exposed from the workpiece when viewed from the first surface side of the workpiece, and the protective film formed in the protective member protection step may be thicker than the protective film formed on the first surface of the workpiece, at least in the region irradiated by the laser beam in the overrun step.

[0013] The coating agent may be made of a water-soluble resin.

[0014] A method for processing a workpiece according to one aspect of the present invention may include a drying step of drying the coating agent before the processing step.

[0015] The protective member may be a resin sheet having a thickness of 100 μm or less.

[0016] A method for processing a workpiece according to one aspect of the present invention may further comprise a cleaning step of cleaning the workpiece unit processed in the processing step, and a dividing step of dividing the workpiece of the workpiece unit that has been cleaned in the cleaning step.

[0017] A workpiece processing apparatus according to one aspect of the present invention includes a spinner table that holds a workpiece unit, which has a first surface and a second surface opposite to the first surface, with a protective member having an area exposed from the workpiece fixed to the second surface, such that the first surface is exposed; a rotating part that rotates the spinner table about a rotation axis intersecting the holding surface; a coating supply part that supplies a coating agent to the first surface and the protective member of the workpiece unit held on the spinner table; a chuck table that holds the workpiece unit such that the first surface is exposed; and the chuck The apparatus comprises a processing unit for processing the workpiece unit held on a rotating table, and a controller, the controller controlling the rotating part to rotate the spinner table holding the workpiece, and controlling the coating supply unit to supply the coating to the central part of the workpiece including a point where the rotation axis of the first surface intersects with the workpiece, thereby performing a workpiece protection step, and controlling the coating supply unit and the rotating part to supply the coating to the region of the protective member of the workpiece unit that is in contact with the outer edge of the workpiece, thereby forming a protective film on the protective member. [Effects of the Invention]

[0018] According to the above embodiments, it is possible to provide a method and apparatus for processing a workpiece that can appropriately protect the protective member near the edge of a workpiece whose back surface is protected by the protective member, and prevent damage to the protective member. [Brief explanation of the drawing]

[0019] [Figure 1] This is a perspective view showing an example of the configuration of a laser processing device. [Figure 2] This is a perspective view showing an example of the configuration of a protective film coating and cleaning apparatus. [Figure 3] This figure shows a first example of a protective film formation process in a laser processing apparatus. [Figure 4] This figure shows a second example of the protective film formation process in a laser processing apparatus. [Figure 5] This is a perspective view showing an example of a laser processing process in a laser processing machine. [Figure 6] It is a diagram showing an example of laser processing in an overrun area by a laser processing apparatus. [Figure 7] It is an enlarged view showing an example of the thickness of the protective film formed in the protective film forming step.

Embodiments for Carrying Out the Invention

[0020] <Definition of Terms, etc.> In this specification, the "workpiece" may, for example, mean the entire object that can be processed by the processing method and processing apparatus of the present embodiment, and may be read as a processing object, a workpiece, a wafer, etc. Further, the "first surface" and "second surface" of the workpiece may mean surfaces located on opposite sides of each other, and the first surface may be read as "upper surface, surface", and the second surface may be read as "lower surface, back surface".

[0021] In this specification, the "protective member" may be any member fixed to the second surface of the workpiece so as to have a region exposed from the above-described workpiece. For example, in addition to a frame and a support substrate, it may be configured to include a fixing member (e.g., a tape or a resin sheet) for fixing the workpiece to the frame and the support substrate.

[0022] In this specification, the "work unit" in which the protective member is fixed to the workpiece may be defined, for example, as a frame unit in which a wafer is fixed to a frame via a tape (e.g., a resin sheet), or a frame unit in which a wafer is positioned in an opening of a frame and the frame and the wafer are integrated by a tape. Further, the "work unit" in this specification may be, for example, a combination of a wafer and a support substrate in which a wafer is fixed to a support substrate having the same shape or substantially the same shape as the wafer. Further, the "workpiece" may be interpreted as a frame unit in which the wafer, tape, and frame are integrated as described above, or a combination of a wafer and a support substrate in which a wafer is fixed to a support substrate. That is, the "workpiece" and the "work unit" may be read interchangeably.

[0023] In this specification, "wafer," as one aspect of "workpiece," may mean, for example, a "semiconductor wafer," which is the base of a semiconductor integrated circuit. A semiconductor wafer may be realized as a disc of appropriate thickness obtained by cutting a single-crystal column made by growing silicon (Si) or silicon carbide (SiC) into a thin disc of appropriate thickness. Furthermore, "wafer" may not be limited to semiconductor components, but may refer to a wafer-shaped workpiece made of various materials such as silicon (Si), silicon carbide (SiC), glass, or resin. In this specification, when simply referring to "wafer," it may be used as a broad concept that includes not only semiconductor wafers but also wafer-shaped workpieces not limited to semiconductor components. Also, "wafer" and "semiconductor wafer" may be read as interchangeable (in particular, even when referring to a semiconductor wafer, it may be interpreted as referring to a wafer-shaped workpiece not limited to a semiconductor component).

[0024] In this specification, "coating agent" refers to various resins, such as water-soluble resists, that are supplied to and coat the exposed portions of the protective member on the first surface side of the workpiece of the work unit, and also on the peripheral edge side of the first surface. Specific examples of coating agents include PVA (polyvinyl alcohol), PEG (polyethylene glycol), PEO (polyethylene oxide), PVP (polyvinylpyrrolidone), etc. In this specification, the dried and cured "coating agent" may become the "protective film" (the pre-drying and curing stage may be called the "coating agent," and the post-drying and curing stage may be called the "protective film").

[0025] In this specification, there is flexibility in the "processing" applied to the workpiece (e.g., wafer) of the work unit, but it can be applied to processes such as laser processing, where the workpiece is processed with a laser beam; cutting, where the workpiece is cut with an annular cutting blade; polishing, where the workpiece is polished with a polishing pad; and grinding, where the workpiece is ground with a grinding wheel.

[0026] In this specification, "at least a portion of the thickness of the protective film formed on the protective member in the protective film formation process is greater than the thickness of the protective film formed on the first surface of the workpiece" may mean that there exists a portion of the protective film formed on the upper surface of the protective member from the highest (farthest) position from the upper surface of the protective member, and that this distance exceeds the distance of the protective film formed on the upper surface (first surface) of the workpiece from the highest (farthest) position from the upper surface (first surface) of the workpiece. Such exceeding portion may include an overrun region where the processing extends beyond the peripheral edge (edge ​​portion, boundary portion) of the upper surface (first surface) of the workpiece during the processing of the upper surface (first surface) of the workpiece. There only needs to be at least one such exceeding portion, and it does not necessarily mean that the total thickness of the protective film formed on the upper surface of the protective member is greater than the thickness of the protective film formed on the upper surface (first surface) of the workpiece.

[0027] The protective film formation process may include a workpiece protection process in which a protective film is formed on the first surface of the workpiece, and a protective member protection process in which a protective film is formed on the region of the protective member of the workpiece unit that is in contact with the outer edge of the workpiece. In the workpiece protection process, any protective film that spills out when forming the protective film on the first surface of the workpiece may be supplied (scattered) to the protective film formation region on the upper surface of the protective member. In the protective member protection process, any protective film that spills out when forming the protective film on the protective film formation region on the upper surface of the protective member may be supplied (scattered) to the first surface of the workpiece. In this sense (in a strict sense), the workpiece protection process and the protective member protection process included in the protective film formation process may be in a relationship where one includes the other.

[0028] The workpiece (e.g., a wafer) may have a circular outer shape with a portion of its outer circumference cut out in plan view. The cut-out portion may consist of, for example, a notch or an orientation flat to indicate or position the crystal orientation of the workpiece. The notch may be a V-shaped (or nearly V-shaped) cut-out of the circular outer shape, and the orientation flat may be a linear cut-out of the circular outer shape. The notch may be applied to workpieces of a predetermined size or larger (e.g., 8 to 12 inches), and the orientation flat may be applied to workpieces smaller than a predetermined size (e.g., 1 to 6 inches).

[0029] <An example of a laser processing device applying a workpiece processing method> As an example of a processing apparatus to which the workpiece processing method of this embodiment is applied, a laser processing apparatus 1 will be described.

[0030] Figure 1 is a perspective view showing an example of the configuration of the laser processing apparatus 1. In Figure 1, a three-dimensional space is defined, and the directions of the X, Y, and Z axes, which are mutually orthogonal, are defined. The plane defined by the X-axis and Y-axis directions (the plane containing the X-axis and Y-axis directions) may constitute a horizontal plane, and the Z-axis direction may be vertical. Figure 2 is a perspective view showing an example of the configuration of the protective film coating and cleaning apparatus (spin coater) 110. Figure 3 is a diagram showing a first example of the protective film formation process in the laser processing apparatus 1. Figure 4 is a diagram showing a second example of the protective film formation process in the laser processing apparatus 1. Figure 5 is a perspective view showing an example of the laser processing process in the laser processing apparatus 1. Figure 6 is a diagram showing an example of laser processing of the overrun region by the laser processing apparatus 1. Figure 7 is an enlarged view showing an example of the thickness of the protective film formed in the protective film formation process.

[0031] The laser processing apparatus 1 has a base 10 that supports each component of the laser processing apparatus 1. The base 10 has a rectangular parallelepiped base 11 and a wall 12 that extends upward (towards the positive side in the Z-axis direction) at the rear end (the negative end in the Y-axis direction) of the base 11. A chuck table 20 that sucks and holds a frame unit (work unit) 50, which will be described later, is arranged on the upper surface of the base 11.

[0032] Below the chuck table 20 is a Y-axis movement unit 30 that moves the chuck table 20 in the Y-axis direction (indexing feed direction). The Y-axis movement unit 30 is fixed to the upper surface of the base 11 and includes a pair of Y-axis guide rails 31 that are parallel to the Y-axis direction. The Y-axis movement table 32 is slidably mounted on the Y-axis guide rails 31. A nut portion (not shown) is provided on the negative side (back side, bottom side) of the Y-axis movement table 32 in the Z-axis direction, and a Y-axis ball screw 33 parallel to the Y-axis guide rail 31 is rotatably connected to this nut portion. A Y-axis pulse motor 34 is connected to one end of the Y-axis ball screw 33. When the Y-axis pulse motor 34 rotates the Y-axis ball screw 33, the Y-axis movement table 32 moves in the Y-axis direction along the Y-axis guide rail 31.

[0033] An X-axis moving unit 40 is provided on the positive side (front side, top side) of the Y-axis moving table 32 in the Z-axis direction, which moves the chuck table 20 in the X-axis direction (machining feed direction) perpendicular to the Y-axis direction. The X-axis moving unit 40 is fixed to the top surface of the Y-axis moving table 32 and includes a pair of X-axis guide rails 41 parallel to the X-axis direction. The X-axis moving table 42 is slidably mounted on the X-axis guide rails 41. A nut portion (not shown) is provided on the negative side (back side, bottom side) of the X-axis moving table 42 in the Z-axis direction, and an X-axis ball screw 43 parallel to the X-axis guide rail 41 is rotatably connected to this nut portion. An X-axis pulse motor 44 is connected to one end of the X-axis ball screw 43. When the X-axis pulse motor 44 rotates the X-axis ball screw 43, the X-axis moving table 42 moves in the X-axis direction along the X-axis guide rail 41.

[0034] A support base 45 is provided on the positive side (surface side, top side) of the X-axis moving table 42 in the Z-axis direction. A chuck table 20 is positioned on the upper part of the support base 45. A holding surface 21 is formed on the surface of the chuck table 20 to attract and hold the frame unit (work unit) 50, which will be described later. Negative pressure from a suction source (not shown) acts on this holding surface 21 through a flow path (not shown) formed inside the chuck table 20, generating a suction force that attracts the frame unit (work unit) 50, which will be described later. The chuck table 20 is connected to a rotation drive source (not shown) located below it and rotates around the Z-axis. Four clamps 22 are provided around the chuck table 20 to clamp and fix the frame unit (work unit) 50, which will be described later, from all four sides.

[0035] Here, the configuration of the frame unit (workpiece unit) 50 including the workpiece (object to be processed) by the laser processing apparatus 1 will be described in detail with reference to Figure 5. The frame unit 50 can be defined as a frame unit in which a wafer (workpiece, object to be processed) 60 is fixed to a frame 80 via tape (e.g., a resin sheet) 70. Furthermore, the frame unit 50 can be defined as a frame unit in which the wafer (workpiece, object to be processed) 60 is positioned in an opening in the frame 80 and the frame 80 and wafer 60 are integrated by tape (e.g., a resin sheet) 70.

[0036] The wafer 60 may be, for example, a substantially disc-shaped substrate made of materials such as Si (silicon), SiC (silicon carbide), GaN (gallium nitride), GaAs (gallium arsenide), or other semiconductor materials, or a material such as sapphire, glass, or quartz. The glass may be, for example, alkali glass, alkali-free glass, soda-lime glass, lead glass, borosilicate glass, or quartz glass.

[0037] The wafer 60 has a first surface (top surface, front surface) 61 and a second surface (bottom surface, back surface) 62 opposite to the first surface. The first surface 61 of the wafer 60 is divided by a plurality of division lines (streets) 63 arranged in a grid pattern. Devices 64 such as ICs (Integrated Circuits), LSIs (Large Scale Integrations), and LEDs (Light Emitting Diodes) are formed in each region of the first surface 61 of the wafer 60 that is divided by the division lines 63. In the wafer (workpiece) 60 processing method according to this embodiment, individual device chips are formed by dividing the wafer 60 by forming division grooves along the division lines 63 in the wafer 60 using laser processing (e.g., ablation processing).

[0038] Before the wafer 60 is loaded into the laser beam irradiation unit (processing unit) 100, which will be described later, where laser processing (e.g., ablation processing) is performed, the wafer 60, tape 70, and frame 80 are integrated to form a frame unit 50. The wafer 60, in the form of the frame unit 50, is loaded into the laser beam irradiation unit 100, which will be described later, and processed. The formed individual device chips are supported by the tape 70 without being separated. Subsequently, the tape 70 is expanded to widen the spacing between the device chips, and the device chips are picked up by a pickup device.

[0039] The frame 80 is a ring frame made of a material such as metal and has an opening 81 with a larger diameter than the wafer 60. When forming the frame unit 50, the wafer 60 is positioned near the center of the opening 81 of the frame 80 and housed in the opening 81. The tape 70 is a flexible resin sheet with flat front and back surfaces. The tape 70 has a larger diameter than the opening 81 of the frame 80 and is fixed (adhered, joined) to the lower surface of the frame 80. Furthermore, the second surface 62 of the wafer 60 is fixed (adhered, joined) to the upper surface of the tape 70 exposed to the opening 81 of the frame 80. In addition, the tape 70, which functions as a protective member as described later, can be made of a resin sheet having a thickness of 100 μm or less, for example. In this embodiment, even when using a thin tape (resin sheet) 70 of 100 μm or less, it is possible to prevent damage to the tape (resin sheet) 70 during laser processing (the detailed mechanism will be described later).

[0040] In this way, a frame unit (work unit) 50 is formed in which a tape 70 having an area exposed from the wafer (workpiece) 60 and a frame 80 (protective member) are fixed to the second surface 62 of a wafer (workpiece) 60 having a first surface 61 and a second surface 62 opposite to the first surface 61.

[0041] In the frame unit 50, the wafer (workpiece) 60 has notches 65 formed on its outer circumferential surface (outer edge, outer side surface) to indicate and position the crystal orientation of the wafer (workpiece) 60. In addition, the frame unit 50 has notches 82 formed on its outer circumferential surface (outer edge, outer side surface) to position the frame 80. For example, in the chuck table 20, the frame unit 50 can be rotated while the frame unit 50 is held by suction, and the position of at least one of the notches 65 and 82 is detected by a line sensor (not shown) in the detection unit in relation to the rotation angle of the chuck table 20, thereby allowing the frame unit 50 to be positioned. Furthermore, the notches 65 and 82 may also be used to position the wafer 60 and the frame 80 in the circumferential direction. In this way, the frame unit 50 (including the wafer 60 as the workpiece) has a circular (not shown) outer shape with a part of the outer circumference cut out in a plan view.

[0042] Returning to the description of the laser processing apparatus 1, a support arm 90 extending forward is provided on the upper front surface of the wall portion 12 (the positive side in the Z-axis direction and the positive side in the Y-axis direction), and a processing head 101 of the laser beam irradiation unit 100 is provided at the tip of this support arm 90. The laser beam irradiation unit 100 is configured to include a laser oscillator (not shown). The processing head 101 is configured to include a focusing lens that focuses the laser beam emitted from the laser oscillator onto the wafer 60 of the frame unit 50 held by the chuck table 20.

[0043] The chuck table 20 is positioned below the processing head 101 of the laser beam irradiation unit 100, and the laser beam irradiated from the processing head 101 performs laser processing (e.g., ablation) on the wafer 60 of the frame unit 50 held by the holding surface 21 of the chuck table 20.

[0044] As shown in Figure 5, the chuck table 20, and by extension the frame unit 50 (wafer 60) held on the chuck table 20, can be moved (processed feed) along a direction parallel to the upper surface. When laser processing (ablation processing) the wafer 60, the frame unit 50 is placed on the chuck table 20, and the wafer 60 is held on the chuck table 20 via the tape 70. Then, the chuck table 20 is rotated to align the planned division line 63 of the wafer 60 with the processing feed direction of the laser beam irradiation unit 100. In addition, the relative positions of the chuck table 20 and the laser beam irradiation unit 100 are adjusted so that the processing head 101 is positioned above the extension of the planned division line 63.

[0045] While irradiating the wafer 60 with a laser beam LB from the laser beam irradiation unit 100 (processing head 101), the chuck table 20 and the laser beam irradiation unit 100 (processing head 101) are moved relative to each other along the processing feed direction parallel to the upper surface of the chuck table 20. As a result, the laser beam LB is irradiated onto the wafer 60 along the planned division line 63, and a division groove along the planned division line 63 is formed on the wafer 60 by ablation.

[0046] After performing ablation along one division line 63, the chuck table 20 and the laser beam irradiation unit 100 (processing head 101) are moved relative to the indexing feed direction perpendicular to the processing feed direction, and the wafer 60 is similarly ablated along the other division line 63. After forming division grooves along all division lines 63 in one direction, the chuck table 20 is rotated around an axis perpendicular to the holding surface 21, and the wafer 60 is similarly ablated along the division lines 63 in the other direction. When the wafer 60 has been ablated along all division lines 63, the division step is complete. Once the division step is complete and division grooves from the first surface 61 to the second surface 62 are formed on the wafer 60 along all division lines 63, the wafer 60 is divided to form individual device chips.

[0047] As will be explained in more detail later, when the laser beam irradiation unit 100 (processing head 101) performs laser processing (ablation processing) on ​​the wafer 60, the laser processing (ablation processing) may extend to the edge of the wafer 60 (the boundary with the tape 70, which acts as a protective material), and even to a position slightly beyond that edge (the wafer-adjacent region of the tape 70, called the overrun region).

[0048] On the upper front surface of the wall section 12, a transport device 120 is provided on the side (negative side in the X-axis direction) of the support arm 90 for transporting the frame unit 50 on the chuck table 20 to the spinner table 111 of the protective film coating and cleaning device (spin coater) 110. The transport device 120 transports the frame unit 50 between the chuck table 20 (laser beam irradiation unit 100) and the protective film coating and cleaning device (spin coater) 110.

[0049] The transport device 120 is configured to include a holding arm 122 having a plurality of suction parts 121 that suction and hold the upper surface of the frame 80 of the frame unit 50, a lifting part 123 that raises and lowers the holding arm 122, a horizontal moving part 124 to which the lifting part 123 is connected and moves horizontally in the X-axis direction, and an X-axis moving mechanism 125 for moving the horizontal moving part 124.

[0050] The X-axis movement mechanism 125 comprises a pair of X-axis guide rails 126 provided horizontally on the front surface of the wall portion 12, an X-axis ball screw 127 positioned between the X-axis guide rails 126, and an X-axis pulse motor 128 provided at one end of the X-axis ball screw 127. The X-axis ball screw 127 is inserted through a nut portion (not shown) provided on the horizontal movement portion 124. When the X-axis pulse motor 128 rotates the X-axis ball screw 127, the horizontal movement portion 124 moves along the X-axis guide rails 126 in the X-axis direction, and the holding arm 122 also moves in the X-axis direction accordingly.

[0051] Next, the configuration of the protective film coating and cleaning apparatus (spin coater) 110 will be described with reference to Figures 2 to 4.

[0052] The protective film coating and cleaning device 110 comprises a spinner table 111 that is rotationally driven by a motor (not shown), a support base 112 that supports and raises the lower part of the spinner table 111, a clamp 113 that holds the frame unit 50 held by the spinner table 111, swinging arms 114, 115, and 116 that are each swung by a motor (not shown), and a housing 1100 that constitutes the internal space surrounding these.

[0053] The spinner table 111 has a suction holding portion 1111 that forms a flat holding surface and a frame holding portion 1112 that surrounds the suction holding portion 1111. The portion of the frame unit 50 corresponding to the wafer 60 is held by suction from below in the suction holding portion 1111, and the frame 80 of the frame unit 50 is supported in the frame holding portion 1112.

[0054] The frame holding portion 1112 of the spinner table 111 is provided with four pendulum-type clamps 113, which tilt due to the centrifugal force generated by the rotation of the spinner table 111, pressing down on and clamping the frame 80 of the frame unit 50 from above.

[0055] The suction holding portion (holding surface) 1111 of the spinner table 111 has the function of holding a frame unit (work unit) 50, which has a tape 70 having an area exposed from the wafer 60 and a frame 80 (protective member) fixed to the second surface 62 of a wafer (workpiece) 60 having a first surface 61 and a second surface 62 opposite to the first surface 61, so that the first surface 61 is exposed. The rotational drive mechanism (e.g., motor) that rotates the spinner table 111 constitutes a "rotating portion" that rotates the spinner table 111 around a rotation axis that intersects (e.g., orthogonal to) the suction holding portion (holding surface) 1111.

[0056] The oscillating arms 114, 115, and 116 are arranged to swing horizontally above the spinner table 111. A protective film resin supply nozzle 1140 is provided at the tip of one of the oscillating arms 114, and water-soluble resin (coating agent) WSR is supplied downward from the protective film resin supply nozzle 1140. The water-soluble resin (coating agent) WSR is a material for forming a protective film (the water-soluble resin (coating agent) WSR becomes a protective film when it dries and hardens), and is composed of, for example, PVA (polyvinyl alcohol), PEG (polyethylene glycol), PEO (polyethylene oxide), PVP (polyvinylpyrrolidone), etc.

[0057] The protective film resin supply nozzle 1140 is connected to a water-soluble resin supply source 1142 via a supply control valve 1141. The water-soluble resin (coating agent) WSR is supplied from the protective film resin supply nozzle 1140 by the opening and closing control of the supply control valve 1141 by the controller 130 (Figure 1). Driven by the motor 1143, the swing arm 114 connected to the tip of the rotating support column 1144 swings, causing the protective film resin supply nozzle 1140 to move above the frame unit 50 (wafer 60).

[0058] Here, the oscillating arm 114 (protective film resin supply nozzle 1140) is configured to extend and retract radially so that it can move the target of the protective film resin (water-soluble resin (coating agent) WSR) between the center of the frame unit 50 held on the spinner table 111 (the center of the wafer 60, which is approximately circular in plan view) and the peripheral part of the frame unit 50 held on the spinner table 111 (the outer periphery of the wafer 60, which is approximately circular in plan view, and the boundary with the tape 70). Figure 3 shows the extended state in which the oscillating arm 114 (protective film resin supply nozzle 1140) has set the target of the protective film resin (water-soluble resin (coating agent) WSR) on the center of the frame unit 50 held on the spinner table 111 (the center of the wafer 60, which is approximately circular in plan view). Figure 4 shows the retracted state in which the oscillating arm 114 (protective film resin supply nozzle 1140) has set a target for the protective film resin (water-soluble resin (coating agent) WSR) on the peripheral area of ​​the frame unit 50 held by the spinner table 111 (the outer periphery of the wafer 60, which is roughly circular in plan view, and the boundary with the tape 70). The extension and retraction of the oscillating arm 114 (protective film resin supply nozzle 1140) is performed under the control of the controller 130.

[0059] Thus, the oscillating arm 114 (protective film resin supply nozzle 1140) and related components (for example, supply control valve 1141, water-soluble resin supply source 1142, motor 1143, rotating support column 1144, etc.) function as a "coating agent supply unit" that supplies protective film resin (water-soluble resin (coating agent) WSR) to the first surface 61 of the frame unit (work unit) 50 held on the spinner table 111, and consequently to protective members such as the tape 70 and frame 80 of the wafer (workpiece) 60.

[0060] A cleaning fluid supply nozzle 1150 is provided at the tip of the oscillating arm 115, and cleaning fluid is supplied from the cleaning fluid supply nozzle 1150. The cleaning fluid may be a single liquid such as pure water, or a mixed fluid (two fluids) obtained by mixing a liquid such as pure water with a gas such as air.

[0061] The cleaning fluid supply nozzle 1150 is connected to a pure water supply source 1152 via a mixing device 140 and a supply control valve 1151, and is also connected to a gas supply source 1154 via a mixing device 140 and a supply control valve 1153. Driven by a motor (not shown), a swing arm 115 connected to the tip of a rotating support column 1155 swings, causing the cleaning fluid supply nozzle 1150 to move above the frame unit 50 (wafer 60).

[0062] In the mixing device 140, when only the supply control valve 1151 is opened by the controller 130, only pure water flows to the cleaning fluid supply nozzle 1150. When both the supply control valve 1151 and the supply control valve 1153 are opened by the controller 130, pure water and air are mixed in the mixing device 140, and the mixed fluid flows to the cleaning fluid supply nozzle 1150. Alternatively, mixing may be performed in the cleaning fluid supply nozzle 1150 instead of in the mixing device 140.

[0063] A drying air supply nozzle 1160 is provided at the tip of the oscillating arm 116, and drying air is supplied from the drying air supply nozzle 1160. The drying air is a gas such as high-pressure air, and it removes liquid adhering to the surface (second surface) of the frame unit 50 (wafer 60). The drying air supply nozzle 1160 is connected to a gas supply source (not shown) that supplies the drying gas via a supply control valve (not shown) controlled by the controller 130. Driven by a motor (not shown), the oscillating arm 116, which is connected to the tip of the rotating support column 1155, oscillates, and the drying air supply nozzle 1160 moves above the frame unit 50 (wafer 60).

[0064] Here, similar to the oscillating arm 114 (protective film resin supply nozzle 1140), the oscillating arm 115 (cleaning fluid supply nozzle 1150) may also be configured to extend and retract radially so that the target of the cleaning fluid can be moved between the center of the frame unit 50 held on the spinner table 111 (the center of the wafer 60, which is approximately circular in plan view) and the peripheral part of the frame unit 50 held on the spinner table 111 (the outer periphery of the wafer 60, which is approximately circular in plan view, and the boundary with the tape 70). Similarly, the oscillating arm 116 (drying air supply nozzle 1160) may also be configured to extend and retract radially so that the target of the drying air can be moved between the center of the frame unit 50 held on the spinner table 111 (the center of the wafer 60, which is approximately circular in plan view) and the peripheral part of the frame unit 50 held on the spinner table 111 (the outer periphery of the wafer 60, which is approximately circular in plan view, and the boundary with the tape 70).

[0065] <Each step in the process of processing a workpiece using a laser processing device> Next, the process of processing the frame unit 50 (wafer 60) using the laser processing apparatus 1 will be described. The control of the following various operations may be automatically controlled by the controller 130 (Figure 1) that controls each component of the laser processing apparatus 1.

[0066] ≪Preparation process≫ A frame unit (workpiece unit) 50 is prepared in which a tape 70 having an area exposed from the wafer (workpiece) 60 and a frame 80 (protective member) are fixed to the second surface 62 of a wafer (workpiece) 60 having a first surface 61 and a second surface 62 opposite to the first surface 61.

[0067] ≪Protective film formation process≫ Water-soluble resin (coating agent) WSR is supplied to the first surface 61 side of the wafer (workpiece) 60 of the frame unit (work unit) 50 to form a protective film PM made of water-soluble resin (coating agent) WSR across the first surface 61 of the wafer (workpiece) 60 and the protective member (tape 70 and frame 80, in this case the wafer-adjacent region of tape 70). As described above, the protective film PM is formed by drying and curing the water-soluble resin (coating agent) WSR. Figures 3 and 4 show the water-soluble resin (coating agent) WSR before drying and curing, and Figures 6 and 7 show the protective film PM after drying and curing.

[0068] The protective film formation process includes a "workpiece protection process (wafer protection process)" in which a protective film PM is formed on the first surface 61 of the wafer (workpiece) 60, and a "protective member protection process (tape protection process)" in which a protective film PM is formed on the region of the protective member (tape 70) of the frame unit (work unit) 50 that is in contact with the outer edge of the wafer (workpiece) 60.

[0069] In the workpiece protection process (wafer protection process), the frame unit 50 is transported by the transport device 120 to the protective film coating and cleaning device (spin coater) 110, where it is held on the spinner table 111. Next, the oscillating arm 114 (protective film resin supply nozzle 1140) is positioned at the center of the frame unit 50 held on the spinner table 111 (the center of the wafer 60, which is approximately circular in plan view), and while rotating the spinner table 111 and thus the frame unit 50, the water-soluble resin (coating agent) WSR is dropped from the protective film resin supply nozzle 1140 onto the center of the first surface 61 of the wafer 60 (see Figure 3). As a result, the water-soluble resin (coating agent) WSR spreads over the entire surface of the first surface 61 of the wafer 60, and a protective film PM is formed in that area.

[0070] In the protective member protection process (tape protection process), the oscillating arm 114 (protective film resin supply nozzle 1140) is positioned around the periphery of the frame unit 50 held on the spinner table 111 (the outer periphery of the wafer 60, which is roughly circular in plan view, and the boundary with the tape 70). While rotating the spinner table 111 and thus the frame unit 50, the water-soluble resin (coating agent) WSR is dropped from the protective film resin supply nozzle 1140 onto the outer periphery of the first surface 61 of the wafer 60 and the boundary with the tape 70 (see Figure 4). As a result, the water-soluble resin (coating agent) WSR is supplied to the region of the protective member (tape 70) of the frame unit 50 that is in contact with the outer edge of the wafer (workpiece) 60, and a protective film PM is formed in that region. In the protective member protection process (tape protection process), when supplying the water-soluble resin (coating agent) WSR and forming the protective film PM, instead of spreading the water-soluble resin (coating agent) WSR by centrifugal force, the water-soluble resin (coating agent) WSR may be applied linearly (annularly) to the outer periphery (edge) of the first surface 61 of the wafer 60 or to the boundary with the tape 70.

[0071] Thus, the protective film formation process may be performed over (spanning) at least two steps: the workpiece protection process (wafer protection process) and the protective member protection process (tape protection process). Furthermore, in either the workpiece protection process (wafer protection process) or the protective member protection process (tape protection process), the water-soluble resin (coating agent) WSR may be supplied along the wafer-adjacent region of the wafer (workpiece) 60 and tape 70 while the supply unit (oscillating arm 114 (protective film resin supply nozzle 1140)) that supplies the water-soluble resin (coating agent) WSR and the frame unit (workpiece unit) 50 are moved relatively (rotated relatively) to form a protective film PM in that region.

[0072] In the workpiece protection process (wafer protection process), when forming a protective film PM on the first surface 61 of the wafer (workpiece) 60, excess protective film PM may be supplied (splattered) onto the protective film formation area on the upper surface of the protective member (tape 70). In the protective member protection process (tape protection process), when forming a protective film PM on the protective film formation area on the upper surface of the protective member (tape 70), excess protective film PM may be supplied (splattered) onto the first surface 61 of the wafer (workpiece) 60. In this sense (strictly speaking), the workpiece protection process (wafer protection process) and the protective member protection process (tape protection process) may be related in such a way that one includes the other.

[0073] In this embodiment, the thickness of at least a portion of the protective film PM formed on the protective member (tape 70) during the protective film formation process is set to be greater than the thickness of the protective film PM formed on the first surface 61 of the wafer (workpiece) 60.

[0074] More specifically, the laser processing process described later includes an overrun process in which a laser beam is irradiated onto the area (overrun region) where the protective member (tape 70) is exposed from the wafer (workpiece) 60 when viewed from the first surface 61 side of the wafer (workpiece) 60 (see Figures 5 and 6). Furthermore, the protective film PM formed in the protective member protection process (tape protection process) is set to be thicker than the protective film PM formed on the first surface 61 of the wafer (workpiece) 60, at least in the area (overrun region) where the laser beam is irradiated in the overrun process (see Figures 6 and 7).

[0075] In Figure 7, the thickness (μm) of the protective film PM formed on the first surface 61 of the wafer (workpiece) 60 is indicated by the symbol X, and the thickness (μm) of the protective film PM formed in the overrun region of the tape 70 is indicated by the symbol Y. The thickness X (μm) of the protective film PM formed on the first surface 61 of the wafer 60 can be set to, for example, 0.1 μm or more and less than 5.0 μm. The thickness Y (μm) of the protective film PM formed in the overrun region of the tape 70 can be set to, for example, 5.0 μm or more and less than (or less than) 30 μm. Thus, it is preferable that the thickness X of the protective film PM formed on the first surface 61 of the wafer 60 and the thickness Y of the protective film PM formed in the overrun region of the tape 70 satisfy Y > X, more preferably Y > 2X, and even more preferably Y > 5X. The effects of setting the thicknesses X and Y of the protective film PM in this way will be explained in detail in the laser processing process described later.

[0076] Furthermore, the thicknesses X and Y of the protective film PM described above may be set such that, for example, the protective film PM formed on the first surface 61 of the wafer 60 and the protective film PM formed in the overrun region of the tape 70 are on the same surface, substantially on the same surface, or form a curved surface (inclined surface) whose height gradually decreases from the first surface 61 of the wafer 60 to the overrun region of the tape 70. When the protective film PM is formed in the overrun region in a curved surface (inclined surface) shape, the relationship between the thicknesses X and Y of the protective film PM (how much Y exceeds X) may vary depending on the position of the overrun region.

[0077] The thickness of the protective film PM, formed by drying and curing the water-soluble resin (coating agent) WSR, can be measured using various film thickness measuring devices.

[0078] Regarding the order in which the workpiece protection process (wafer protection process) and the protective member protection process (tape protection process) are performed, the workpiece protection process (wafer protection process) may be performed first and the protective member protection process (tape protection process) may be performed later, or conversely, the protective member protection process (tape protection process) may be performed first and the workpiece protection process (wafer protection process) may be performed later.

[0079] When the workpiece protection process (wafer protection process) is performed first and the protective member protection process (tape protection process) is performed later, the water-soluble resin (coating agent) WSR and subsequently the protective film PM are supplied and formed sequentially from the inner circumference (center side) to the outer circumference (periphery side) of the frame unit 50 (wafer 60), allowing the protective film formation process to be executed smoothly. Furthermore, in the protective member protection process, by applying the water-soluble resin (coating agent) WSR while blowing it from the inner circumference (center side) to the outer circumference (periphery side) of the frame unit 50 (wafer 60), scattering of the water-soluble resin (coating agent) WSR onto the wafer 60 can be prevented.

[0080] When the protective member protection process (tape protection process) is performed first and the workpiece protection process (wafer protection process) is performed later, the water-soluble resin (coating agent) WSR, which is thicker than the amount supplied and applied to the overrun region of the tape 70, can be dried and cured earlier to form a protective film PM. Furthermore, the thick protective film PM that is formed earlier in the overrun region of the tape 70 acts as a dike (embankment), which helps to prevent the scattering of the water-soluble resin (coating agent) WSR supplied and applied to the first surface 61 of the wafer 60.

[0081] Furthermore, from the standpoint of preventing the scattering of the water-soluble resin (coating agent) WSR, it is effective to tilt the orientation of the protective film resin supply nozzle 1140 (for example, by setting it to face outwards or towards the outer circumference) in either the case where the workpiece protection process (wafer protection process) is performed first and the protective member protection process (tape protection process) is performed later, or the case where the protective member protection process (tape protection process) is performed first and the workpiece protection process (wafer protection process) is performed later.

[0082] Furthermore, in order to prevent the formation of air bubbles in the water-soluble resin (coating agent) WSR and consequently the protective film PM, which is thicker than the overrun region of the tape 70, it is effective to supply and apply the water-soluble resin (coating agent) WSR from the protective film resin supply nozzle 1140 to the outer periphery (edge) of the wafer 60 of the frame unit 50 and the boundary with the tape 70 over at least two turns.

[0083] Furthermore, the protective film formation process (workpiece protection process, protective member protection process) may be performed by spray coating instead of spin coating, or by supplying a water-soluble resin (coating agent) using a separate arm. In other words, the specific form of the protective film formation process can be appropriately modified as long as the thickness X of the protective film PM formed on the first surface 61 of the wafer 60 and the thickness Y of the protective film PM formed in the overrun region of the tape 70 satisfy Y > X. For example, the spinner table 111 and the frame unit 50 (a combination of the wafer 60, tape 70, and frame 80) held by the spinner table 111 are rotated at a low speed, and a water-soluble resin (coating agent) may be supplied to the overrun region (outer edge region) of the tape 70 from the protective film resin supply nozzle 1140, while the water-soluble resin (coating agent) may be supplied in a circular pattern to the first surface 61 of the wafer 60 using an arm separate from the protective film resin supply nozzle 1140. Alternatively, the water-soluble resin (coating agent) supplied to the first surface 61 of the wafer 60 may be brought to the overrun region (outer edge region) of the tape 70 by the centrifugal force caused by rotation. In this case, it is preferable to supply the water-soluble resin (coating agent) near the outer edge rather than the center of the wafer 60.

[0084] As described above, the wafer (workpiece) 60 has a circular (approximately circular) outer shape with a portion of its outer circumference cut out in plan view. In other words, the wafer 60 has a notch 65 on a portion of its outer circumference. Alternatively, although not shown in the illustration, the wafer 60 may have an orientation flat on a portion of its outer circumference instead of a notch 65. In this case, the water-soluble resin (coating agent) WSR may also be supplied to the notch 65 and the orientation flat, so as not to affect the edge alignment performance caused by the notch 65 or the orientation flat.

[0085] When supplying water-soluble resin (coating agent) WSR to the orientation flat of wafer 60, the spinner table 111 is rotated by a "rotating part" consisting of a rotation drive mechanism (e.g., a motor) around a rotation axis that intersects (e.g., orthogonal to) the suction holding part (holding surface) 1111, while the oscillating arm 114 (protective film resin supply nozzle 1140) is simultaneously moved. This control allows for the water-soluble resin (coating agent) WSR to be suitably supplied along the straight sections of the orientation flat of wafer 60. Furthermore, even when forming an arbitrary shape on wafer 60 by combining straight lines and curves, the water-soluble resin (coating agent) WSR can be supplied along the arbitrary shape using the same control.

[0086] ≪Drying process (coating agent drying process, protective film formation process)≫ A drying process is performed to dry the water-soluble resin (coating agent) WSR before the processing process (laser processing process) described later. This drying process dries and hardens the water-soluble resin (coating agent) WSR, forming a protective film PM. The drying process may be performed, for example, by installing a dedicated heater (not shown). Alternatively, the drying process may be performed by a drying air supply nozzle 1160 supported by a rocking arm 116. For example, the drying process may be performed by moving the rocking arm 116 (drying air supply nozzle 1160) from the center of the frame unit 50 held on the spinner table 111 (the center of the wafer 60, which is approximately circular in plan view) to the peripheral part of the frame unit 50 held on the spinner table 111 (the outer periphery of the wafer 60, which is approximately circular in plan view, or the boundary with the tape 70), while blowing drying air onto the water-soluble resin (coating agent) WSR. In the drying process, the drying time for the thicker water-soluble resin (coating agent) WSR supplied and applied to the overrun region of the tape 70 may be extended.

[0087] ≪Processing steps (laser processing steps)≫ The transfer device 120 transports the frame unit 50 (wafer 60) from the spinner table 111 of the protective film coating and cleaning device 110 to the holding surface 21 of the chuck table 20, and performs a processing step on the frame unit 50 (wafer 60 or tape 70) on which the protective film PM has been formed, starting from the first surface 61 side of the wafer 60. More specifically, a laser processing step is performed in which a laser beam is irradiated onto the wafer 60 by the laser beam irradiation unit 100 (processing head 101).

[0088] Here, the laser processing step includes an overrun step in which a laser beam is irradiated onto the region of the tape 70 that is exposed from the wafer 60 when viewed from the first surface 61 side of the wafer 60 (the overrun region, which is the wafer-adjacent region of the tape 70) (see Figures 5 and 6).

[0089] In the laser processing process, the protective film PM formed on the first surface 61 of the wafer 60 functions to prevent molten material (debris) generated by laser irradiation from adhering to the first surface 61 of the wafer 60.

[0090] On the other hand, conventional laser processing equipment has the following technical challenges due to the irradiation of the laser beam into the overrun region, which is the area of ​​the tape adjacent to the wafer. In recent years, devices have become smaller, and the thickness of the wafers to be processed has decreased (for example, to about 50 μm or less). As the wafer thickness decreases, the distance between the laser focusing point and the protective material (tape) decreases, and the thermal impact on the protective material (tape) increases. In particular, when irradiating the laser along the line to be divided on the wafer, the laser may be irradiated from one end of the line to the other, i.e., from edge to edge of the wafer, as well as beyond the edge (overrun region). In this case, the protective material (tape) may be directly irradiated with the laser, causing it to melt, which may result in the protective material (tape) sticking to the holding surface of the chuck table, making transport difficult. In particular, if the protective material is a thin tape (resin sheet) of 100 μm or less, the tape is more likely to melt and stick to the holding surface of the chuck table. Furthermore, if heated molten material (debris) scattered by laser irradiation adheres to the protective material (tape), similar effects may occur. Incidentally, if the protective material is a support substrate, the support substrate may be damaged, making it difficult to reuse.

[0091] In this embodiment, the above-mentioned problems are considered important technical challenges, and the thickness Y (μm) of at least a portion of the protective film PM formed on the tape (protective member) 70 in the protective film formation process is set to be greater than the thickness X (μm) of the protective film PM formed on the first surface 61 of the wafer (workpiece) 60 (Y>X). More specifically, the protective film PM formed on the tape (protective member) 70 in the protective film formation process is set to be thicker than the protective film PM formed on the first surface 61 of the wafer (workpiece) 60, at least in the region where the laser beam is irradiated in the overrun process (overrun region) (Y>X).

[0092] Thus, even if the laser irradiation of the tape 70 extends beyond the edge of the first surface 61 of the wafer 60 to the wafer-adjacent region (overrun region) during laser processing, the protective film PM in the wafer-adjacent region (overrun region) is formed to be sufficiently thick (it is set to be thicker than the protective film PM formed on the first surface 61 of the wafer 60 (Y>X)). Therefore, problems such as the tape 70 melting due to direct laser irradiation of the wafer-adjacent region (overrun region) of the tape 70, or the melted tape 70 sticking to the holding surface 21 of the chuck table 20, can be reliably prevented.

[0093] ≪Cleaning Process≫ The frame unit 50 (a combination of wafer 60, tape 70, and frame 80) that has been processed (laser processed) in the processing step (laser processing step) is cleaned. That is, the protective film PM is removed from the frame unit 50 along with the molten material (debris) generated in the laser processing step.

[0094] More specifically, the transfer device 120 transfers the frame unit 50 from the holding surface 21 of the chuck table 20 to the spinner table 111 of the protective film coating and cleaning device 110, and the frame unit 50 is held on the spinner table 111 with the first surface 61 of the wafer 60 covered with the protective film PM and the wafer-adjacent region (overrun region) of the tape 70 exposed.

[0095] Next, the spinner table 111 holding the frame unit 50 is rotated, and a first cleaning fluid (for example, a single liquid such as pure water) is supplied from the oscillating arm 115 (cleaning fluid supply nozzle 1150) toward the first surface 61 of the wafer 60 or the wafer-adjacent region (overrun region) of the tape 70 (cleaning with the first cleaning fluid). Next, the spinner table 111 holding the frame unit 50 is rotated, and a second cleaning fluid (for example, a mixed fluid of a liquid such as pure water and a gas such as air, a two-fluid mixture) is supplied from the oscillating arm 115 (cleaning fluid supply nozzle 1150) toward the first surface 61 of the wafer 60 or the wafer-adjacent region (overrun region) of the tape 70 (cleaning with the second cleaning fluid).

[0096] ≪Drying Process (Frame Unit Drying Process)≫ The frame unit 50 is dried by spinning the spinner table 111, which holds the frame unit 50, at a higher speed than during the cleaning process. Alternatively, drying air is supplied (blowed) from the oscillating arm 116 (drying air supply nozzle 1160) towards the first surface 61 of the wafer 60 or the wafer-adjacent region (overrun region) of the tape 70. This removes the cleaning fluid (e.g., the first and second cleaning fluids) supplied during the cleaning process from the frame unit 50.

[0097] ≪Dividing process≫ The frame unit 50, which has been cleaned in the cleaning process and dried in the drying process, is transported out by a transport mechanism (not shown), and the wafer (workpiece) 60 of the frame unit 50 is divided. More specifically, the wafer 60 has been ablated along all the planned division lines 63, and division grooves have been formed along all the planned division lines 63 from the first surface 61 to the second surface 62. The wafer 60 is then divided along these division grooves to form individual device chips.

[0098] <Examples of application to cutting and grinding equipment> Although the above embodiment describes an example of application to a laser processing apparatus, the workpiece processing method and processing apparatus of this embodiment can also be applied to other processing apparatuses such as cutting apparatuses and grinding apparatuses.

[0099] In conventional cutting and grinding equipment, when cutting or grinding blades are applied to a workpiece (wafer) to perform cutting or grinding, the blade may extend beyond the edge of the workpiece (wafer) to the overrun area of ​​the protective component. In this case, the protective component (tape, frame, support substrate, etc.) may be damaged by the blade directly contacting the protective component or by the adhesion and hardening of processing debris.

[0100] In this regard, according to the workpiece processing method of this embodiment, even if the cutting or grinding blade extends beyond the edge of the workpiece (wafer) to the overrun region of the protective member, the protective film in the overrun region is formed to be sufficiently thick (thicker than the protective film formed on the upper surface (first surface) of the workpiece (wafer) (Y>X)). Therefore, problems such as the blade directly acting on the overrun region of the protective member or processing debris adhering to and sticking to it can be reliably prevented.

[0101] <Processing apparatus for workpieces according to this embodiment> The workpiece processing apparatus of this embodiment has the following constituent elements. First, it has a spinner table 111 that holds a frame unit (workpiece unit) 50, to which a tape 70 having an area exposed from the wafer 60 and a frame 80 (protective member) are fixed, on the second surface 62 of a wafer (workpiece) 60 having a first surface 61 and a second surface 62 opposite to the first surface 61, on a suction holding part (holding surface) 1111 such that the first surface 61 is exposed. Furthermore, a rotational drive mechanism (e.g., a motor) that rotates the spinner table 111 constitutes a "rotating part" that rotates the spinner table 111 around a rotation axis that intersects (e.g., orthogonal to) the suction holding part (holding surface) 1111. Furthermore, the oscillating arm 114 (protective film resin supply nozzle 1140) and related components (e.g., supply control valve 1141, water-soluble resin supply source 1142, motor 1143, rotating support column 1144, etc.) function as a "coating agent supply unit" that supplies protective film resin (water-soluble resin (coating agent) WSR) to the first surface 61 of the frame unit (work unit) 50 and thus the wafer (workpiece) 60 held on the spinner table 111, and to protective members such as the tape 70 and frame 80. The chuck table 20 also holds the frame unit (work unit) 50 so that the first surface 61 of the wafer (workpiece) 60 is exposed. The laser beam irradiation unit (processing unit) 100 processes the frame unit (work unit) 50 and thus the wafer (workpiece) 60 held on the chuck table 20.

[0102] Then, the controller 130 performs the workpiece protection process and the protective member protection process.

[0103] In the workpiece protection process, the controller 130 controls a rotating part (e.g., a drive motor) to rotate the spinner table 111 that holds the wafer (workpiece) 60, and controls a coating supply unit (e.g., a oscillating arm 114 or a protective film resin supply nozzle 1140) to supply protective film resin (water-soluble resin (coating agent) WSR) to the center of the first surface 61 of the wafer (workpiece) 60, including a point that intersects (e.g., orthogonally) with the axis of rotation, thereby forming a protective film PM on the first surface 61.

[0104] In the protective member protection process, the controller 130 controls the coating supply unit (e.g., the oscillating arm 114 and the protective film resin supply nozzle 1140) and the rotating unit (e.g., the drive motor) to supply protective film resin (water-soluble resin (coating agent) WSR) to the area of ​​the protective member of the frame unit (work unit) 50 that is in contact with the outer edge of the wafer (workpiece) 60 (e.g., the wafer-adjacent area of ​​the tape 70, the overrun area), thereby forming a protective film PM in that area (e.g., the wafer-adjacent area of ​​the tape 70, the overrun area).

[0105] As described above, the workpiece processing method of this embodiment comprises a preparation step of preparing a work unit in which a protective member having an area exposed from the workpiece is fixed to the second surface of a workpiece having a first surface and a second surface opposite to the first surface; a protective film forming step of supplying a coating agent to the first surface side of the work unit to form a protective film made of the coating agent on the first surface of the workpiece and the protective member; and a processing step of processing the work unit on which the protective film has been formed from the first surface side of the workpiece, wherein the thickness of at least a portion of the protective film formed on the protective member in the protective film forming step is greater than the thickness of the protective film formed on the first surface of the workpiece.

[0106] Furthermore, the workpiece processing apparatus of this embodiment includes a spinner table that holds a workpiece unit, which has a first surface and a second surface opposite to the first surface, with a protective member having an area exposed from the workpiece fixed to the second surface, such that the first surface is exposed; a rotating part that rotates the spinner table about a rotation axis that intersects the holding surface; a coating supply part that supplies a coating agent to the first surface and the protective member of the workpiece unit held on the spinner table; a chuck table that holds the workpiece unit such that the first surface is exposed; and the chuck The apparatus comprises a processing unit for processing the workpiece unit held on a rotating table, and a controller, the controller controlling the rotating part to rotate the spinner table holding the workpiece, and controlling the coating supply unit to supply the coating to the center of the workpiece including a point where the rotation axis of the first surface intersects with the workpiece, thereby performing a workpiece protection step, and controlling the coating supply unit and the rotating part to supply the coating to the region of the protective member of the workpiece unit that is in contact with the outer edge of the workpiece, thereby performing a protective member protection step, thereby forming a protective film on the protective member.

[0107] This makes it possible to provide a workpiece processing method and processing apparatus that can properly protect the protective member near the edge of a workpiece whose back surface is protected by the protective member, thereby preventing damage to the protective member.

[0108] Furthermore, the embodiments of the present invention are not limited to the embodiments and modifications described above, and may be modified, substituted, or altered in various ways without departing from the spirit of the technical idea of ​​the present invention. Moreover, if the technical idea of ​​the present invention can be realized in a different way by advances in the art or by other derived arts, it may be implemented by that method. Accordingly, the claims cover all embodiments that may fall within the scope of the technical idea of ​​the present invention. [Industrial applicability]

[0109] As described above, the present invention can be applied, for example, to a method and apparatus for processing a workpiece, which comprises the steps of supplying a coating agent to a workpiece unit in which a protective member and a workpiece are joined, and processing the workpiece. [Explanation of Symbols]

[0110] 1: Laser processing equipment (processing equipment) 10: Base 20: Chuck Table 30: Y-axis movement unit 40: X-axis movement unit 50: Frame unit (work unit) 60: Wafer (workpiece, workpiece) 61: 1st surface (top surface, front surface) 62: 2nd side (bottom side, back side) 65: Notch 70: Tape (protective material, resin sheet) 80: Frame (protective components, ring frame) 90: Support arm 100: Laser beam irradiation unit (processing section) 110: Protective film coating and cleaning equipment (spin coater) 114: Swiveling arm (supply unit, coating agent supply unit) 1140: Protective film resin supply nozzle (supply unit, coating agent supply unit) 115: Swivel Arm 1150: Cleaning fluid supply nozzle 116: Swivel Arm 1160: Dry air supply nozzle 120: Conveying device 130: Controller 140: Mixing device WSR: Water-soluble resin (coating agent) PM:Protective film LB: Laser beam

Claims

1. A preparation step of preparing a work unit in which a protective member having a region exposed from the workpiece is fixed to the second surface of a workpiece having a first surface and a second surface opposite to the first surface, A protective film forming step involves supplying a coating agent to the first surface side of the workpiece of the work unit to form a protective film made of the coating agent on the first surface of the workpiece and the protective member, A processing step of performing processing on the workpiece from the first surface side of the workpiece with respect to the workpiece unit on which the protective film has been formed, Equipped with, In the protective film forming process, the thickness of at least a portion of the protective film formed on the protective member is greater than the thickness of the protective film formed on the first surface of the workpiece. A method for processing a workpiece, characterized by the features described above.

2. The protective film formation step is, A workpiece protection step in which the protective film is formed on the first surface of the workpiece, A protective member protection step of forming a protective film in the region of the protective member of the work unit that is in contact with the outer edge of the workpiece, Having, The method for processing a workpiece as described in feature 1.

3. In the protective member protection process, the supply unit that supplies the coating agent and the work unit are moved relative to each other to supply the coating agent along the workpiece. The method for processing a workpiece as described in feature 2.

4. The workpiece has a circular outer shape with a portion of its outer circumference cut out in a plan view. The method for processing a workpiece as described in feature 3.

5. The processing step includes a laser processing step of irradiating the workpiece with a laser beam. A method for processing a workpiece according to any one of claims 1 to 4.

6. The protective film formation step includes a protective member protection step in which the protective film is formed in the region of the protective member of the work unit that is in contact with the outer edge of the workpiece, The laser processing step includes an overrun step of irradiating the laser beam onto the area where the protective member is exposed from the workpiece when viewed from the first surface side of the workpiece. The protective film formed in the protective member protection step is thicker than the protective film formed on the first surface of the workpiece, at least in the region irradiated by the laser beam in the overrun step. The method for processing a workpiece according to feature 5.

7. The coating agent is made of a water-soluble resin. A method for processing a workpiece according to any one of claims 1 to 4.

8. The process includes a drying step to dry the coating before the processing step. A method for processing a workpiece according to any one of claims 1 to 4.

9. The protective member is a resin sheet having a thickness of 100 μm or less. A method for processing a workpiece according to any one of claims 1 to 4.

10. A cleaning step for cleaning the work unit processed in the processing step, A dividing step for dividing the workpiece of the work unit that has been cleaned in the cleaning step, It also has, A method for processing a workpiece according to any one of claims 1 to 4.

11. A spinner table holds a workpiece unit, which has a first surface and a second surface opposite to the first surface, with a protective member fixed to the second surface of the workpiece having an area exposed from the workpiece, so that the first surface is exposed. A rotating part that rotates the spinner table about a rotation axis that intersects the holding surface, A coating supply unit that supplies a coating agent to the first surface and the protective member of the work unit held on the spinner table, A chuck table that holds the work unit so that the first surface is exposed, A machining section for machining the workpiece unit held on the chuck table, Controller and Equipped with, The controller is, A workpiece protection step comprising: controlling the rotating part to rotate the spinner table that holds the workpiece, controlling the coating supply part to supply the coating to the center of the workpiece including the point where the rotation axis of the first surface intersects with the workpiece, and forming a protective film on the first surface; A protective member protection step involves controlling the coating supply unit and the rotating unit to supply the coating to the region of the protective member of the work unit that is in contact with the outer edge of the workpiece, thereby forming a protective film on the protective member. Execute A workpiece processing apparatus characterized by the following features.

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