Sheet fixing method, chip manufacturing method, and pressing device

Abstract

It reduces the minute gap between the surface of the workpiece and the sheet. [Solution] A sheet fixing method for fixing a sheet to one surface of an object to be fixed, comprising: fixing a sheet to one surface of the object to be fixed to form an object to be fixed unit; supporting the object to be fixed unit on a table after the formation of the object to be fixed unit so that the other surface located opposite to the one surface of the object to be fixed is exposed; covering at least the objects to be fixed with a cover member after the formation of the object to be fixed unit; and, after supporting the object to be fixed unit on a table and covering the objects to be fixed with a cover member, making the pressure in the internal space of the cover member covering the objects to be fixed higher than the pressure in the external space of the cover member.

Description

[Technical Field]

[0001] The present invention relates to a method for fixing a sheet to one surface of an object to be fixed, a method for manufacturing chips, which involves fixing a sheet to one surface of the object to be fixed and then dividing the object into multiple chips, and a pressing device for pressing an object to be fixed onto a sheet in order to fix a sheet to one surface of the object to be fixed. [Background technology]

[0002] A processing apparatus is known in which, after attaching a sheet such as tape to the surface of a workpiece such as a semiconductor device wafer, the workpiece is held in place by suction on a holding table via this sheet, and the workpiece is processed by a processing unit such as a cutting unit or a laser beam irradiation unit with the back surface of the workpiece exposed upwards (see, for example, Patent Documents 1 and 2).

[0003] Typically, multiple division lines are arranged in a grid pattern on the surface of a workpiece, and devices such as ICs (Integrated Circuits) are formed in each of the rectangular regions demarcated by these division lines. In some cases, TEGs (Test Element Groups) may also be formed along the division lines.

[0004] Because minute irregularities are formed on the surface of the workpiece by devices, TEGs, etc., when a sheet is attached to the surface of the workpiece, a minute gap is likely to form between the surface of the workpiece and the sheet.

[0005] When a workpiece is divided into device units using the aforementioned processing apparatus while a minute gap is formed between the surface of the workpiece and the sheet, this minute gap can cause cracks, chipping, etc., leading to damage to the device chip. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2010-087141 [Patent Document 2] Japanese Patent Publication No. 2010-082644 [Overview of the project] [Problems that the invention aims to solve]

[0007] This invention has been made in view of the aforementioned problems, and aims to reduce minute gaps between the surface of the workpiece and the sheet. [Means for solving the problem]

[0008] According to one aspect of the present invention, a sheet fixing method is provided for fixing a sheet to one surface of an object to be fixed, comprising: fixing the sheet to the one surface of the object to be fixed to form an object to be fixed unit; supporting the object to be fixed unit on a table after its formation so that the other surface of the object to be fixed opposite to the one surface is exposed; covering at least the object to be fixed with a cover member after its formation; and, after supporting the object to be fixed on the table and covering the object to be fixed with the cover member, making the pressure in the internal space of the cover member covering the object to be fixed higher than the pressure in the external space of the cover member.

[0009] Preferably, when the pressure in the internal space of the cover member is to be higher than the pressure in the external space of the cover member, gas is supplied to the internal space of the cover member, thereby pressing the object to be fixed against the sheet with the gas.

[0010] Preferably, the sheet is a heat-sealable sheet having a base layer and not an adhesive layer made of an adhesive, and when forming the object to be fixed, the base layer is heated and the heat-sealable sheet is heat-pressed onto one side of the object to be fixed.

[0011] Preferably, when the pressure in the internal space of the cover member is to be higher than the pressure in the external space of the cover member, the sheet to be fixed to the object of the fixed object unit is heated while the pressure in the internal space of the cover member is to be higher than the pressure in the external space of the cover member.

[0012] Preferably, when the pressure in the internal space of the cover member is to be higher than the pressure in the external space of the cover member, the sheet is held in place by the table by suction while the pressure in the internal space of the cover member is raised to be higher than the pressure in the external space of the cover member.

[0013] Preferably, when forming the object to be fixed unit, the sheet is fixed to an annular frame having an opening in the radial center and to one surface of the object to be fixed, and the object to be fixed, the frame and the sheet are integrated with the object to be fixed in place at the opening to form the object to be fixed unit.

[0014] According to another aspect of the present invention, a method for manufacturing chips is provided for dividing an object into a plurality of chips after fixing a sheet to one surface of the object to be fixed, comprising: fixing the sheet to the one surface of the object to be fixed to form an object unit; supporting the object unit on a table after its formation so that the other surface of the object opposite to the one surface is exposed; covering at least the object of the object unit with a cover member after its formation; supporting the object unit on the table and covering the object with the cover member, making the pressure in the internal space of the cover member covering the object higher than the pressure in the external space of the cover member; and dividing the object fixed to the sheet into a plurality of chips after making the pressure in the internal space of the cover member higher than the pressure in the external space of the cover member.

[0015] According to still another aspect of the present invention, there is provided a pressing device for pressing an adherend against a sheet to fix the sheet to one surface of the adherend. In an adherend unit in which the sheet is fixed to the one surface, the adherend unit is supported by a table so that the other surface of the adherend located on the opposite side of the one surface is exposed, and a cover member provided above the table and covering at least the adherend supported by the table are provided. A pressing device is provided that presses the adherend against the sheet by making the pressure in the internal space of the cover member higher than the pressure in the external space of the cover member in a state where the cover member covers at least the adherend.

Advantages of the Invention

[0016] In the sheet fixing method according to one aspect of the present invention and the chip manufacturing method according to another aspect of the present invention, after forming an adherend unit by fixing a sheet to one surface of an adherend, the pressure in the internal space of a cover member covering the adherend is made higher than the pressure in the external space of the cover member. Thereby, a minute gap between one surface of the adherend and the sheet can be reduced.

[0017] The pressing device according to still another aspect of the present invention includes a support table and a cover member. In this pressing device, the adherend is pressed against the sheet by making the pressure in the internal space of the cover member higher than the pressure in the external space of the cover member in a state where the cover member covers at least the adherend. Thereby, a minute gap between one surface of the adherend and the sheet can be reduced.

Brief Description of the Drawings

[0018] [Figure 1] It is a flowchart of the sheet fixing method according to the first embodiment. [Figure 2] FIG. 2(A) is a perspective view of a workpiece, and FIG. 2(B) is a perspective view of a frame unit. [Figure 3] It is a schematic view of an attaching device including a pressing device. [Figure 4]FIG. 4(A) is a partial cross-sectional side view showing a state of attaching a sheet to a frame, FIG. 4(B) is a partial cross-sectional side view showing a state of cutting the sheet, and FIG. 4(C) is a cross-sectional view of the frame unit. [Figure 5] FIG. 5(A) is a partial cross-sectional side view of the sheet fixing device, and FIG. 5(B) is a partial cross-sectional side view showing the formation of the workpiece unit. [Figure 6] FIG. 6(A) is a partial cross-sectional side view of the workpiece unit, and FIG. 6(B) is a perspective view of the workpiece unit. [Figure 7] It is a partial cross-sectional side view showing that the workpiece unit is supported by the second chuck table. [Figure 8] FIG. 8(A) is a partial cross-sectional side view of the pressing device, and FIG. 8(B) is a partial cross-sectional side view showing covering at least the workpiece with the chamber. [Figure 9] It is a partial cross-sectional side view showing that the pressure of the internal space of the chamber is made larger than the pressure of the external space of the chamber. [Figure 10] It is a flowchart of the method for manufacturing a chip according to the second embodiment. [Figure 11] FIG. 11(A) is a partial cross-sectional side view showing dividing a workpiece into a plurality of device chips, and FIG. 11(B) is a perspective view of one device chip.

MODE FOR CARRYING OUT THE INVENTION

[0019] (First Embodiment) Referring to the accompanying drawings, an embodiment according to an aspect of the present invention will be described. FIG. 1 is a flowchart of the sheet fixing method according to the first embodiment. In this embodiment, by performing each step in the order of S10, S20, S30, and S40, the sheet 17 shown in FIG. 2(B) is fixed to the workpiece (i.e., the object to be fixed) 11 shown in FIG. 2(A).

[0020] However, the sheet fixing method is not necessarily limited to the order of S10 to S40. In this embodiment, the case in which S30 is performed after S20 is described, but as will be described in detail later, S20 may also be performed after S30.

[0021] First, the workpiece 11, the sheet 17, and the frame 19 will be described. Figure 2(A) is a perspective view of the workpiece 11. The workpiece 11 is disc-shaped (i.e., a plate shape with a circular front and back surface) and includes disc-shaped semiconductor wafers such as silicon (Si), silicon carbide (SiC), and gallium nitride (GaN).

[0022] Each workpiece 11 includes a circular surface (i.e., one side) 11a and a back surface (i.e., the other side) 11b. The back surface 11b is located on the opposite side of the surface 11a. Multiple division lines 13 are set in a grid pattern on the surface 11a.

[0023] A device 15, such as an IC, is formed in each of the multiple regions demarcated by the multiple division lines 13. The division lines 13 have a predetermined width in a direction perpendicular to their longitudinal direction. One or more of the division lines 13 may be provided with the above-mentioned TEG (not shown).

[0024] The entire back surface 11b of the workpiece 11 is covered with a metal film (not shown) made of a metal such as copper (Cu), aluminum (Al), or tungsten (W). In other words, the entire back surface of the semiconductor wafer is covered with a metal film.

[0025] It is not essential that the entire back surface 11b of the workpiece 11 be covered with a metal film. If a metal film is not provided on the back surface 11b, the back surface of the semiconductor wafer will be exposed as the back surface 11b of the workpiece 11.

[0026] Figure 2(B) is a perspective view of a frame unit 21 in which a circular sheet 17 and an annular frame 19 are integrated. In this embodiment, the sheet 17 is made of thermoplastic resin.

[0027] Thermoplastic resins include, for example, (i) polyolefins (PO) such as polyethylene (PE) and polypropylene (PP), (ii) polystyrene (PS), or (iii) polyesters (PEs) such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN).

[0028] The sheet 17 of this embodiment has a single-layer structure formed from the above-mentioned material. Furthermore, the sheet 17 does not have an adhesive layer composed of an adhesive, and only has a base layer. In this embodiment, an adhesive layer composed of an adhesive means that it adheres to an object by applying only slight pressure for a short time under normal temperature and pressure conditions, without using water, heat, etc.

[0029] In this embodiment, by using a sheet 17 that has only a base layer and no adhesive layer, it is advantageous that no part of the adhesive layer remains on the surface 11a as residue after the surface 11a separates from the sheet 17.

[0030] Furthermore, the sheet 17 is not limited to a single-layer structure, but may have a multi-layer structure. For example, the sheet 17 may be composed of two layers, one a relatively thick polyolefin layer and the other a relatively thin polyester layer. In this case, the relatively soft polyolefin layer is fixed to the workpiece 11.

[0031] If sheet 17 has a single-layer structure, sheet 17 has a thickness of, for example, 50 μm to 200 μm. If sheet 17 has a laminated structure, sheet 17 has, for example, a polyolefin layer with a thickness of 100 μm to 150 μm and a polyester layer with a thickness of 10 μm to 50 μm.

[0032] The sheet 17 is a heat-sealable sheet, and when the sheet 17 is fixed to the workpiece 11, it is heated to a predetermined temperature to soften it. The temperature at which the sheet 17 softens varies depending on the material. For example, if the sheet 17 has a single-layer structure made of polyethylene (i.e., it is a polyethylene sheet), the predetermined temperature at which the sheet 17 softens is 120°C or higher and 140°C or lower.

[0033] Furthermore, if the sheet 17 has a single-layer structure made of polypropylene (i.e., it is a polypropylene sheet), the predetermined temperature at which the sheet 17 softens is 160°C to 180°C, and if the sheet 17 has a single-layer structure made of polystyrene (i.e., it is a polystyrene sheet), the predetermined temperature at which the sheet 17 softens is 220°C to 240°C.

[0034] If the sheet 17 has a single-layer structure made of polyethylene terephthalate (i.e., it is a polyethylene terephthalate sheet), the predetermined temperature at which the sheet 17 softens is 250°C or higher and 270°C or lower.

[0035] If the sheet 17 has a single-layer structure made of polyethylene naphthalate (i.e., it is a polyethylene naphthalate sheet), the predetermined temperature at which the sheet 17 softens is 160°C or higher and 180°C or lower.

[0036] The outer periphery of the sheet 17 is fixed to the frame 19. The frame 19 is annular and made of a metal such as stainless steel. The frame 19 has a circular opening 19a in its radial center. The diameter of the opening 19a is larger than the outer diameter of the workpiece 11.

[0037] The outer periphery of the aforementioned sheet 17 is attached to the frame 19 by heat-sealing so as to cover the opening 19a. In other words, the outer diameter of the sheet 17 is larger than the diameter of the opening 19a and smaller than the outer diameter of the frame 19.

[0038] The workpiece 11 is heat-pressed in a sheet fixing device 10, which is part of the adhesive device 2 (see Figure 3), so that the surface 11a of the workpiece 11 is in contact with the sheet 17, and then integrated with the frame 19 and the sheet 17. After that, a process is performed in a pressing device 50, which is also part of the adhesive device 2, to reduce the minute gap 11c (see Figure 7) between the surface 11a and the sheet 17.

[0039] Now, with reference to Figure 3, the adhesive device 2 will be described. Figure 3 is a schematic diagram of the adhesive device 2. In Figure 3, some of the components of the adhesive device 2 are shown as functional blocks. The X-axis direction (left-right direction), Y-axis direction (front-back direction), and Z-axis direction (up-down direction) shown in Figure 3 are orthogonal to each other.

[0040] The adhesive application device 2 has a rectangular parallelepiped base 4 that supports the components of the adhesive application device 2. A pair of cassette placement areas 4a and 4b are provided at the corners of the upper surface of the base 4. Cassette 6a is placed in cassette placement area 4a, and similarly, cassette 6b is placed in cassette placement area 4b. Multiple workpieces 11 are contained in cassettes 6a and 6b.

[0041] A horizontal articulated transport robot 8 is provided behind the cassette mounting areas 4a and 4b (i.e., on one side in the Y-axis direction). The transport robot 8 uses an end effector that enters cassette 6a or cassette 6b to suck and hold one workpiece 11, and then transports the workpiece 11 to a sheet fixing device 10 located behind the transport robot 8.

[0042] The sheet fixing device 10 will now be described with reference to Figures 5(A) and 5(B). The sheet fixing device 10 has a disc-shaped first chuck table 12, and the workpiece 11 conveyed by the conveying robot 8 is placed on the first chuck table 12.

[0043] The first chuck table 12 has a disc-shaped frame made of a metal such as stainless steel. A disc-shaped recess is concentrically provided in the radial center of the frame. A disc-shaped porous plate made of porous ceramics is fixed in this recess.

[0044] The upper surfaces of the frame and the porous plate are substantially flush, forming a substantially flat holding surface 12a. A suction source (not shown), such as a vacuum pump, is connected to the frame, and negative pressure can be transmitted from the suction source to the upper surface of the porous plate.

[0045] The frame of the first chuck table 12 is equipped with a heating element 12b, such as a cartridge heater. The heat generated by the heating element 12b is transferred from the holding surface 12a to the sheet 17 via the workpiece 11, softening the sheet 17 when heat-pressing is performed.

[0046] In this embodiment, the first chuck table 12 holds the workpiece 11 by suction using negative pressure transmitted to the holding surface 12a, but the first chuck table 12 may also be an electrostatic chuck that uses electrostatic force or the like to attract the workpiece 11.

[0047] A cylindrical frame support base 14 is provided around the first chuck table 12. Multiple suction ports 14a are provided on the upper surface of the frame support base 14 at approximately equal intervals along the circumferential direction of the frame support base 14. A suction source (not shown), such as a vacuum pump, is connected to the frame support base 14, and negative pressure can be transmitted from the suction source to each suction port 14a.

[0048] In this embodiment, the frame support base 14 is movable along the Z-axis direction by an actuator (not shown) (a ball screw including a screw shaft connected to a motor, an air cylinder, etc.) to a high position P1 that receives the frame unit 21 and a low position P2 where the sheet 17 is positioned when it is attached to the workpiece 11.

[0049] However, the first chuck table 12 may be movable in the Z-axis direction, and both the first chuck table 12 and the frame support base 14 may be movable in the Z-axis direction. That is, the first chuck table 12 and the frame support base 14 only need to be relatively movable in the Z-axis direction.

[0050] Furthermore, the frame support base 14 may have claws for clamping and fixing the frame 19 between itself and the upper surface of the frame support base 14, either in place of or in conjunction with the negative pressure supplied from the multiple suction ports 14a.

[0051] A cylindrical chamber 16 is provided near the first chuck table 12 (for example, above it), large enough to cover the first chuck table 12 and the frame support base 14 (in Figure 3, the approximate location of the chamber 16 is shown by a dashed line).

[0052] Chamber 16 is movable along the Z-axis direction by an actuator (not shown) (such as a ball screw including a screw shaft connected to a motor, or an air cylinder). When chamber 16 is in the upper position, the workpiece 11 and frame unit 21 are transported to the first chuck table 12 and frame support base 14.

[0053] After the workpiece 11 and frame unit 21 have been transported, the chamber 16 moves to a lower position to cover the first chuck table 12, frame support base 14, etc., and together with a support base (not shown) located below the chamber 16, forms a sealed space.

[0054] A suction source (not shown), such as a vacuum pump, is connected to the chamber 16 via a tubular section (not shown). A solenoid valve (not shown) is provided in the tubular section. In this embodiment, with the suction source operating, the solenoid valve is opened to create a vacuum (for example, 10°C) inside the chamber 16. -1 Pa or more 10 2 A medium vacuum of Pa or less, or 10 2 Pa or more 10 5 (The following low vacuum)

[0055] A cylindrical pressure roller 18 is provided above the holding surface 12a, with its longitudinal portion aligned along the X-axis. Note that the pressure roller 18 is omitted in Figure 3. The pressure roller 18 is movable along both the Z-axis and Y-axis directions.

[0056] The length of the longitudinal portion of the pressure roller 18 in the X-axis direction is greater than the outer diameter of the frame 19. The pressure roller 18 can move along the Y-axis direction while rotating while pressing the sheet 17 against the frame 19.

[0057] The frame unit 21 used in the sheet fastening device 10 is formed by a frame unit forming device 20 located behind the first chuck table 12. The frame unit forming device 20 will now be described with reference to Figure 4(A).

[0058] The frame unit forming apparatus 20 has a cylindrical sheet support base 22. The sheet support base 22 is a metal base with a substantially flat top surface. Around the sheet support base 22, cylindrical frame support bases 24 are arranged concentrically, spaced apart from the sheet support base 22.

[0059] In the Z-axis direction, the upper surface of the frame support base 24 is lower than the upper surface of the seat support base 22 by the thickness of the frame 19. Multiple suction ports 24a are provided on the upper surface of the frame support base 24 at approximately equal intervals along the circumferential direction of the frame support base 24. Negative pressure is transmitted to each suction port 24a from a suction source (not shown), such as a vacuum pump.

[0060] A heating element 24b, such as a cartridge heater, is provided inside the frame support base 24. The heat generated by the heating element 24b is transferred to the sheet 17 via the frame 19, softening the sheet 17 when it is heat-pressed to the frame 19.

[0061] Returning to Figure 3, a frame supply unit 30 is located on one side of the frame unit forming apparatus 20 in the X-axis direction. The frame supply unit 30 includes a frame stocker 32 that houses a plurality of frames 19 stacked in the Z-axis direction.

[0062] A first conveying device 34 is provided near the frame stocker 32 for suction-holding and transporting one frame 19. The first conveying device 34 includes a suction unit 34a for suction-holding the frame 19 and a movable block 34b that can move along the X-axis direction.

[0063] The suction unit 34a has a bracket whose longitudinal portion is arranged along the Y-axis. Suction blocks are provided at both ends of the bracket. Each suction block has two suction pads arranged so as to sandwich the bracket in the X-axis direction.

[0064] The suction unit 34a is configured to be movable in the Z-axis direction relative to the movable block 34b by an actuator such as an air cylinder. The movable block 34b is moved in the X-axis direction by a moving mechanism (not shown). The moving mechanism (not shown) has, for example, a ball screw.

[0065] In this case, the movable block 34b is slidably fixed to a pair of guide rails, and a screw shaft is rotatably connected to a nut fixed to the movable block 34b. A motor, such as a servo motor, is connected to one end of the screw shaft.

[0066] After the suction unit 34a, positioned directly above the frame stocker 32, holds the frame 19 in place by negative pressure, the moving block 34b moves along the X-axis until the frame 19 is positioned directly above the frame support base 24 (see Figure 4(A)).

[0067] By combining the movement of the movable block 34b in the X-axis direction and the movement of the suction unit 34a in the Z-axis direction, one frame 19 is placed from the frame stocker 32 onto the frame support base 24. After the frame 19 is held in place by suction on the frame support base 24, the sheet 17 is attached to the frame 19.

[0068] Figure 4(A) is a partial cross-sectional side view showing the process of attaching a sheet 17 to a frame 19 in the frame unit forming apparatus 20. Note that the sheet support base 22 and frame support base 24 shown in Figure 4(A) are omitted in Figure 3.

[0069] Behind the sheet support base 22 is a roll body 17a around which an unused sheet 17 is wound, and a pair of feed rollers 26a for feeding the sheet 17 from the roll body 17a are provided between the roll body 17a and the sheet support base 22 in the Y-axis direction.

[0070] A motor (not shown) transmits power to a pair of feed rollers 26a, which move the sheet 17 sandwiched between the pair of feed rollers 26a forward (i.e., to the other side in the Y-axis direction). In the Y-axis direction, on the opposite side of the pair of feed rollers 26a, with the sheet support base 22 in between, there is an additional pair of feed rollers 26b for moving the sheet 17.

[0071] Power is transmitted from a motor (not shown) to the pair of feed rollers 26b, and in a manner synchronized with the pair of feed rollers 26a, the sheet 17 sandwiched between the pair of feed rollers 26b is moved forward. Note that the pair of feed rollers 26a and 26b are omitted in Figure 3.

[0072] The sheet 17, fed by the pair of feed rollers 26b, is wound up on the rotating shaft 26c. Power is also transmitted to the rotating shaft 26c from a motor (not shown) in synchronization with the pair of feed rollers 26a and the pair of feed rollers 26b.

[0073] A cutting unit 28 is provided above the sheet support base 22. The cutting unit 28 is movable along the Z-axis direction between a retracted position (see Figure 4(A)) and a cutting position (see Figure 4(B)) by a Z-axis direction movement mechanism (not shown).

[0074] The cutting unit 28 has a cylindrical rotating shaft 28a. Power is transmitted to the rotating shaft 28a from a motor (not shown). The base end of an arm 28b is fixed to the lower end of the rotating shaft 28a, and a cutting blade 28c is fixed to the tip of the arm 28b in such a manner that it protrudes downward from the arm 28b.

[0075] A cylindrical pressing roller 29 is provided above the sheet support base 22 and near the cutting unit 28. The pressing roller 29 is movable along the Z-axis direction between a retracted position (upper position in Figure 4(A)) and a pressing position (lower position in Figure 4(A)) by a Z-axis direction movement mechanism (not shown).

[0076] The pressure roller 29 is movable along the Z-axis and also along the Y-axis. The longitudinal length of the pressure roller 29 is greater than the outer diameter of the frame 19. The pressure roller 29 can move along the Y-axis while rotating with the sheet 17 pressed against the frame 19.

[0077] As shown in Figures 4(A) to 4(C), the frame unit forming apparatus 20 forms a frame unit 21 by heat-pressing a sheet 17 onto a frame 19. When forming the frame unit 21, the first conveying apparatus 34 holds the frame 19 by suction and moves between the sheet 17 and the frame support base 24, and places the frame 19 on the frame support base 24.

[0078] Then, as shown in Figure 4(A), one side of the frame 19 is held in place by the frame support base 24. Next, the first position P in the Y-axis direction is achieved. A The pressing roller 29 is lowered to press the sheet 17, which is positioned above the sheet support base 22 and the frame support base 24, with the pressing roller 29. First position P AIt is located between the inner peripheral edge and the outer peripheral edge of the frame 19 in the Y-axis direction.

[0079] During thermocompression bonding, the frame 19 is heated to a temperature corresponding to the softening point of the sheet 17 by the heat of the heating element 24b. Then, while pressing the sheet 17 with the pressing roller 29, the pressing roller 29 is moved along the Y-axis direction to the second position P B while rotating it. Thereby, the sheet 17 is thermocompression bonded to the frame 19.

[0080] The second position P B is also located between the inner peripheral edge and the outer peripheral edge of the frame 19 in the Y-axis direction. For example, the distance from the center of the opening 19a to the first position P A is the same as the distance from the center of the opening 19a to the second position P B is the same.

[0081] Next, after retracting the pressing roller 29, the lower end of the cutting blade 28c is cut into the sheet 17, and the arm portion 28b is rotated to cut the sheet 17 circularly along the opening 19a of the frame 19. In this way, the frame unit 21 is formed.

[0082] FIG. 4(B) is a partial cross-sectional side view showing the state of cutting the sheet 17 with the cutting unit 28, and FIG. 4(C) is a cross-sectional view of the frame unit 21. In this embodiment, the sheet 17 is attached (i.e., fixed) to the frame 19 by thermocompression bonding. However, the sheet 17 may have an adhesive layer made of an adhesive in the annular region in contact with the frame 19.

[0083] After cutting the sheet 17, the cutting unit 28 is retracted above the pair of feed rollers 26a, 26b, and the used sheet 17 is wound up by the rotary shaft 26c until the unused sheet 17 covers the entire sheet support base 22 and the frame support base 24.

[0084] The frame unit 21 is transported from the frame unit forming device 20 to the sheet fixing device 10 by the second transport device 44 (see Figure 3). As shown in Figure 3, the second transport device 44 is located near the sheet fixing device 10 and the frame unit forming device 20.

[0085] The second transport device 44, like the first transport device 34, has a suction unit 44a that holds the frame 19 by suction, and a movable block 44b that can move along the Y-axis direction.

[0086] The suction unit 44a has a bracket whose longitudinal portion is arranged along the X-axis. Suction blocks are provided at both ends of the bracket. Each suction block has two suction pads arranged so as to sandwich the bracket in the Y-axis direction. The suction unit 44a is also configured to be movable in the Z-axis direction relative to the movable block 44b.

[0087] In the chamber 16 of the sheet fixing device 10, as described above, the sheet 17 is fixed to the surface 11a of the workpiece 11 to form a workpiece unit (i.e., a fixed workpiece unit) 23 (see Figures 6(A) and 6(B)).

[0088] Subsequently, a third conveying device 46, positioned in front of the frame stocker 32, conveys the workpiece unit 23 to the pressing device 50 (see Figure 3). The third conveying device 46, like the first conveying device 34, has a suction unit 46a that holds the frame 19 by suction, and a movable block 46b that can move along the X-axis direction.

[0089] The suction unit 46a has a bracket whose longitudinal portion is arranged along the Y-axis. Suction blocks are provided at both ends of the bracket. Each suction block has two suction pads positioned so as to sandwich the bracket between them.

[0090] The suction unit 46a is configured to be movable in the Z-axis direction relative to the movable block 46b. The bracket of the suction unit 46a is configured to be rotatable around a rotation axis parallel to the Y-axis direction by a motor (not shown).

[0091] The suction unit 46a enters below the workpiece unit 23 lifted by the suction unit 44a of the second conveying device 44, and supports and holds the frame 19 from below. Subsequently, the suction unit 44a releases the suction hold of the frame 19.

[0092] Next, the suction unit 46a inverts the frame 19 while holding it in suction, reversing the orientation of the workpiece unit 23 so that the back surface 11b is exposed upwards, and places the workpiece unit 23 on the second chuck table (i.e., table) 52 (see Figure 7) of the pressing device 50.

[0093] As shown in Figure 7, the pressing device 50 has a disc-shaped second chuck table 52. The second chuck table 52 has a larger diameter than the first chuck table 12 and supports the entire workpiece unit 23 so that the back surface 11b of the workpiece 11 is exposed.

[0094] The second chuck table 52 has a disc-shaped frame made of a metal such as stainless steel. A disc-shaped recess is concentrically provided in the radial center of the frame, and a disc-shaped porous plate made of porous ceramics is fixed in this recess.

[0095] The upper surfaces of the frame and the porous plate are substantially flush, forming a substantially flat holding surface 52a. Negative pressure is transmitted to the upper surface of the porous plate from a suction source (not shown), such as a vacuum pump. The workpiece unit 23 placed on the holding surface 52a is held in place by suction from the holding surface 52a.

[0096] Furthermore, the second chuck table 52 is not limited to negative pressure, but may also be an electrostatic chuck that uses electrostatic force or the like to attract the workpiece unit 23.

[0097] The frame of the second chuck table 52 is equipped with a heating element 52b, such as a cartridge heater. The heat generated by the heating element 52b is transferred from the holding surface 52a to the sheet 17, softening the sheet 17 when the workpiece 11 is pressed against it.

[0098] Furthermore, the frame of the second chuck table 52 is provided with a plurality of (for example) four through holes (not shown) such that one end of each hole is exposed to the holding surface 52a. Each through hole is provided with a push-up pin (not shown) that is movable along the Z-axis direction.

[0099] The push-up pins are normally housed within the through-holes, but after the predetermined processing in the pressing device 50 is completed, when the workpiece unit 23 is lifted, their upper ends protrude above the holding surface 52a. As a result, the workpiece unit 23 is lifted by multiple push-up pins.

[0100] The second chuck table 52 is configured to be movable within a predetermined range in the Y-axis direction by an actuator (not shown) such as a ball screw including a screw shaft connected to a motor, or an air cylinder.

[0101] Above the second chuck table 52, a top-cylindrical chamber (i.e., cover member) 54 made of a metal such as stainless steel is provided (see Figure 8(A)). As shown in Figure 8(A), a rubber or resin seal ring 54a is provided at the bottom of the chamber 54, along the circumferential direction of the chamber 54.

[0102] In this embodiment, the diameter of the chamber 54 is greater than the outer diameter of the workpiece 11 and smaller than the inner diameter of the frame 19. Therefore, the chamber 54 can cover at least the workpiece 11 and the central part of the sheet 17 within the workpiece unit 23. In Figure 3, the chamber 54 is shown with a dashed line.

[0103] The chamber 54 is provided with a moving mechanism (not shown) that moves the chamber 54 along the Z-axis direction. The moving mechanism has an actuator (motor, ball screw including screw shaft, air cylinder, etc.). When the chamber 54 is lowered by the moving mechanism, the seal ring 54a comes into contact with the seat 17 or the frame 19.

[0104] As a result, the internal space 54b of the chamber 54 becomes a sealed space with the sheet 17 or frame 19. At this time, airtightness between the chamber 54 and the sheet 17 or frame 19 is ensured by the seal ring 54a.

[0105] The diameter of the chamber 54 may be larger than the inner diameter of the opening 19a of the frame 19 and smaller than the outer diameter of the frame 19. In this case, when the chamber 54 is lowered toward the retaining surface 52a, the seal ring 54a will come into contact with the upper surface of the frame 19.

[0106] Thus, the diameter of the chamber 54 may be determined appropriately according to the size of the workpiece 11 or the frame 19. The height 54c that defines the internal space 54b of the chamber 54 is defined, for example, by the length from the lower end of the seal ring 54a to the inner surface of the top plate in the Z-axis direction.

[0107] For example, if the diameter of the workpiece 11 is 200 mm, the inner diameter of the internal space 54b is 204 mm, and the height 54c of the internal space 54b of the chamber 54 is 3 mm. However, the above size of the chamber 54 is just an example.

[0108] A small-diameter opening 54d is provided in the center of the top of the chamber 54. One end of a pipe section 56 is fixed to the opening 54d. A compressed air supply source 58 for supplying compressed air to the chamber 54 is provided at the other end of the pipe section 56.

[0109] The compressed air supply source 58 is installed, for example, in a building such as a factory, and is provided separately from the adhesive device 2. The compressed air supply source 58 includes a compressor that takes in air from the atmosphere and compresses it, a tank that stores the compressed air, a filter that removes dust and other debris, etc. (none of which are shown).

[0110] Between one end and the other end of the pipe section 56, an on-off valve 56a and a pressure control valve 56b are provided, whose opening and closing are controlled by a controller 62. The on-off valve 56a is a solenoid valve that opens and closes the flow path of the pipe section 56, and adjusts the valve opening to 0% or 100%.

[0111] The pressure control valve 56b is a solenoid valve that adjusts the pressure of the air (gas) 58a (see Figure 9) flowing through the passage of the pipe section 56 to a predetermined value. When the on / off valve 56a and the pressure control valve 56b are open, air 58a is supplied to the internal space 54b of the chamber 54 at a predetermined pressure.

[0112] Air 58a at room temperature (i.e., 20°C ± 5°C) is supplied to the internal space 54b of the chamber 54 at a pressure of, for example, 0.1 MPa to 1.0 MPa, more preferably 0.3 MPa to 0.5 MPa.

[0113] Since the internal space 54b of the chamber 54 is very narrow, supplying room temperature air 58a at a predetermined pressure from the compressed air supply source 58 for about 1 second will fill the internal space 54b of the chamber 54 with air 58a. After supplying air 58a to the internal space 54b of the chamber 54, the on-off valve 56a and the pressure control valve 56b are closed.

[0114] In this way, by making the pressure in the internal space 54b of the chamber 54 higher than the pressure in the external space of the chamber 54, the workpiece 11 is pressed against the sheet 17, and the sheet 17 is fixed to the surface 11a of the workpiece 11.

[0115] For example, when pressing the workpiece 11 against the sheet 17, the sheet 17 is heated to its softening point by the second chuck table 52, and the internal space 54b of the chamber 54 is filled with air 58a, and this state is maintained for a predetermined time (for example, 120s to 180s).

[0116] In this embodiment, by pressing the workpiece 11 against the sheet 17, the minute gap 11c between the surface 11a of the workpiece 11 and the sheet 17 can be reduced.

[0117] Furthermore, when pressing the workpiece 11 against the sheet 17 in the internal space 54b of the chamber 54, it is not essential to heat the sheet 17 until it reaches its softening point. Even without heating the sheet 17, it is possible to achieve a certain degree of reduction in the minute gap 11c between the surface 11a of the workpiece 11 and the sheet 17.

[0118] However, an advantage of heating the sheet 17 until it reaches its softening point is that the surface of the sheet 17 that contacts the holding surface 52a (i.e., the surface of the sheet 17 opposite to the surface that contacts the workpiece 11) can be made substantially flat, conforming to the holding surface 52a.

[0119] In addition, if the surface of the sheet 17 that is in contact with the holding surface 52a can be made substantially flat to conform to the holding surface 52a by such heating and pressing, it is advantageous that, unlike conventional techniques in which the sheet 17 or photocurable resin is flattened by cutting with a cutting tool, no cutting chips are generated during the flattening process.

[0120] Now, let's return to Figure 3. A pair of guide rails 60a and a pusher 60b are provided near the pressing device 50. The pair of guide rails 60a are configured to move closer to and further apart from each other along the X-axis direction by an actuator (not shown).

[0121] The pusher 60b is configured to be movable along the Y-axis direction by an actuator (not shown). The pusher 60b pushes the workpiece unit 23, which has been lifted from the holding surface 52a by a plurality of push-up pins, onto a pair of guide rails 60a, and transports the workpiece unit 23 to the cassette 6c located in the cassette mounting area 4c.

[0122] The adhesive application device 2 has a controller 62 that controls the operation of its components. The controller 62 is composed of a computer that includes, for example, a processor 62a, represented by a CPU (Central Processing Unit), and memory 62b.

[0123] Memory 62b includes a main memory such as DRAM (Dynamic Random Access Memory) and an auxiliary memory such as flash memory. Software containing a predetermined program is stored in the auxiliary memory, and the functions of the controller 62 are realized by operating the processor 62a, etc., according to this software.

[0124] Next, each step in Figure 1 will be explained with reference to Figures 5(A) to 9. Figure 5(A) is a partial cross-sectional side view of the sheet fixing device 10, and Figure 5(B) is a partial cross-sectional side view showing the formation of the workpiece unit 23 (S10: sheet fixing step).

[0125] In S10, first, as shown in Figure 5(A), the back surface 11b of the workpiece 11 is held by the first chuck table 12 with suction so that the surface 11a is exposed, and then the frame 19 of the frame unit 21 is held by the frame support base 14 with suction.

[0126] In this state, the chamber 16 is lowered to form a sealed space between the chamber 16 and the sheet 17, and the workpiece 11 and the frame unit 21 are placed in this sealed space. Next, the internal space of the chamber 16 is made into a vacuum. This reduces the possibility of air bubbles being trapped between the sheet 17 and the surface 11a.

[0127] After creating a vacuum in the internal space of the chamber 16, the heating element 12b is energized to heat the first chuck table 12, thereby heating the sheet 17 (i.e., the base layer of the thermocompression sheet) to a temperature corresponding to its softening point.

[0128] Next, the frame support base 14 is lowered relative to the first chuck table 12, positioning the upper surface of the frame 19 between the surface 11a of the workpiece 11 and the holding surface 12a. Then, the sheet 17 is pressed against the workpiece 11 with the pressing roller 18.

[0129] In this state, the sheet 17 is heat-pressed onto the surface 11a of the workpiece 11 by moving the pressing roller 18 while rotating it along the Y-axis. This fixes the sheet 17 to the surface 11a of the workpiece 11.

[0130] In this embodiment, since the sheet 17 is already fixed to the frame 19, in S10, the fixing of the sheet 17 to both the frame 19 and the surface 11a of the workpiece 11 is completed. That is, with the workpiece 11 positioned in the opening 19a of the frame 19, the workpiece 11, the sheet 17, and the frame 19 are integrated to form a workpiece unit 23.

[0131] Figure 6(A) is a partial cross-sectional side view of the workpiece unit 23 formed in S10, and Figure 6(B) is a perspective view of the workpiece unit 23. After the workpiece unit 23 is formed, the second conveying device 44 lifts the workpiece unit 23.

[0132] Then, the third conveying device 46 receives the workpiece unit 23 from the second conveying device 44, inverts the workpiece unit 23, and conveys the workpiece unit 23 to the second chuck table 52 so that the back surface 11b of the workpiece 11 is exposed upwards. As a result, the workpiece unit 23 is supported by the second chuck table 52.

[0133] Figure 7 is a partial cross-sectional side view showing the process of supporting the workpiece unit 23 with the second chuck table 52 (S20: support process). In S20 of this embodiment, the workpiece unit 23 is supported and held by the holding surface 52a.

[0134] Furthermore, after S20 and before S40, a minute gap 11c is formed due to the irregularities of the surface 11a (see the dashed circle in Figure 7). If the workpiece 11 is divided into device units while this minute gap 11c is formed, cracks, chipping, etc. may occur due to the minute gap 11c, potentially damaging the device chip.

[0135] Therefore, in this embodiment, a pressing device 50 is used to reduce the minute gap 11c. Figure 8(A) is a partial cross-sectional side view of the pressing device 50.

[0136] In this embodiment, after S20, the chamber 54 is lowered, and the seal ring 54a located at the lower end of the chamber 54 is brought into contact with the sheet 17, thereby covering at least the workpiece 11 with the chamber 54 (S30: covering step). Figure 8(B) is a partial cross-sectional side view showing S30, in which at least the workpiece 11 is covered with the chamber 54.

[0137] Note that S20 may be performed after S30. If S20 is performed after S30, the chamber 54 and the workpiece unit 23 are lowered while the sealed space defined by the chamber 54 and the sheet 17 is formed, and the workpiece unit 23 is held in place by suction at the holding surface 52a. In other words, S30 can be performed after S10.

[0138] After S20 and S30, the workpiece 11 is pressed against the sheet 17 by increasing the pressure in the internal space 54b of the chamber 54 to be higher than the pressure in the external space of the chamber 54 (S40: pressure control step). Figure 9 is a partial cross-sectional side view showing that the pressure in the internal space 54b of the chamber 54 is increased to be higher than the pressure in the external space of the chamber 54.

[0139] In this embodiment, the pressure in the external space of the chamber 54 refers to the pressure in the space in contact with the outer surface of the chamber 54 and located outside the sealed space enclosed by the chamber 54 and the workpiece unit 23. Of course, before increasing the pressure in the internal space 54b, the pressures in the internal space 54b and the external space are the same.

[0140] Since the sheet 17 in this embodiment is a polyethylene sheet, when S40 is performed, the heating element 52b is energized to heat the second chuck table 52, bringing the holding surface 52a to 140°C, and the sheet 17 held by suction on the holding surface 52a is heated to a temperature corresponding to its softening point.

[0141] Therefore, the timing of the start of heating of the second chuck table 52 may be at S20 or S30. Furthermore, when supplying air 58a to the internal space 54b of the chamber 54 (i.e., starting at S40), the holding surface 52a may be heated to a temperature corresponding to the softening point of the sheet 17.

[0142] In this embodiment, when the holding surface 52a is heated to a temperature corresponding to the softening point of the sheet 17, air 58a is supplied to the internal space 54b of the chamber 54, thereby making the pressure in the internal space 54b of the chamber 54 higher than the pressure in the external space of the chamber 54. As a result, the workpiece 11 is pressed against the sheet 17 by the air 58a.

[0143] For example, room temperature air 58a is supplied to the internal space 54b of the chamber 54 for about 1 second at a pressure of 0.1 MPa to 1.0 MPa, more preferably 0.3 MPa to 0.5 MPa. This fills the internal space 54b of the chamber 54 with air 58a.

[0144] Then, the sheet 17 is heated to its softening point, and the internal space 54b of the chamber 54 is filled with air 58a. This state is maintained for a predetermined time (for example, 120s to 180s). This reduces the minute gap 11c (see the dashed circle in Figure 7) between the surface 11a of the workpiece 11 and the sheet 17.

[0145] By the way, the gas used to press the workpiece 11 within the chamber 54 of the pressing device 50 is not limited to the air 58a described above. Instead of air 58a, an inert gas such as argon (Ar) gas, carbon dioxide (CO2) gas, or nitrogen (N2) gas can also be used.

[0146] Furthermore, the main force pressing the workpiece 11 within the chamber 54 may be a liquid such as pure water instead of a gas. In other words, within the chamber 54, the workpiece 11 may be pressed against the sheet 17 by a gas or liquid fluid. By using a liquid, the workpiece 11 can be pressed with a pressure equivalent to that of a gas even with a relatively simple pump.

[0147] Furthermore, since the specific heat of a liquid is generally greater than that of a gas, using a heated liquid allows for the heating of both the workpiece 11 and the sheet 17 by the heat transferred through the liquid, in addition to pressing the workpiece 11 against the sheet 17.

[0148] In the above embodiment, a case was described in which a standard-shaped container such as stainless steel, called a chamber 54, is used. However, instead, a deformable bag (i.e., a cover member) made of a flexible material such as airbag base fabric may be used for the pressing device 50.

[0149] (Second Embodiment) Next, a second embodiment will be described with reference to Figures 10 and 11. Figure 10 is a flowchart of the manufacturing method of a device chip (i.e., a chip) 25 (see Figure 11(B)) according to the second embodiment.

[0150] In the second embodiment, a sheet 17 is fixed to the surface 11a of the workpiece 11, and after reducing the minute gap 11c between the surface 11a and the sheet 17, the workpiece 11 is divided into a plurality of device chips 25 using a processing device.

[0151] In the second embodiment, steps S10 to S40 are the same as in the first embodiment, so redundant explanations will be omitted. First, referring to Figure 11(A), the cutting device 70 used in dividing the workpiece 11 into multiple device chips 25 (S50: division step) will be described.

[0152] In Figure 11(A), the X-axis direction (machining feed direction), Y-axis direction (indexing feed direction), and Z-axis direction (cutting feed direction) are mutually orthogonal. The cutting apparatus 70 of this embodiment has a disc-shaped chuck table 72. The chuck table 72 has a disc-shaped holding plate 74 having a substantially transparent area that transmits visible light.

[0153] The retaining plate 74 is made of a transparent material such as quartz glass, borosilicate glass, or soda glass. The upper surface of the retaining plate 74 is provided with multiple openings for transmitting negative pressure, and the upper surface of the retaining plate 74 functions as a retaining surface 74a that holds the workpiece 11 by suction via the sheet 17.

[0154] The holding plate 74 is configured to be rotatable by power transmitted from a motor 72b located on the side of the chuck table 72. In addition, multiple frame support parts 72a are provided around the holding plate 74 at approximately equal intervals along the circumferential direction of the holding plate 74. Each frame support part 72a supports the frame 19 and also holds the frame 19 by suction using negative pressure.

[0155] Below the holding plate 74, an imaging unit 76 is provided for imaging the workpiece 11 with visible light. The imaging unit 76 includes a light source including an LED (Light Emitting Diode) and a solid-state image sensor that performs photoelectric conversion.

[0156] The imaging unit 76 irradiates the surface 11a of the workpiece 11 from a light source through an opening 72c provided on the top plate of the chuck table 72, a holding plate 74, and a sheet 17, and images the surface 11a by converting the reflected light from the surface 11a into photoelectric light using an image sensor.

[0157] A cutting unit 78 is provided above the retaining plate 74. The cutting unit 78 has a cylindrical spindle 80 whose longitudinal direction is approximately parallel to the Y-axis direction. A portion of the spindle 80 is rotatably housed in a spindle housing (not shown).

[0158] The spindle 80 rotates at high speed due to a motor (not shown) located inside the spindle housing. The tip of the spindle 80 protrudes outside the spindle housing. A cutting blade 82 having an annular cutting edge is attached to the tip of the spindle 80.

[0159] The cutting blade 82 is, for example, a so-called hub blade in which a cutting edge is fixed to one side of an annular base, but it may also be a so-called hubless blade (i.e., washer type) that has only a cutting edge and no base. A nozzle unit (not shown) for supplying cutting fluid such as pure water to the cutting edge of the cutting blade 82 is provided at the tip of the spindle housing.

[0160] Figure 11(A) is a partial cross-sectional side view showing the division of the workpiece 11 into multiple device chips 25. In S50, after imaging the division line 13 with the imaging unit 76, the orientation of the holding plate 74 is adjusted so that the division line 13 is approximately parallel to the X-axis direction. Then, the spindle 80 is rotated at high speed, and the lower end of the cutting blade 82 is positioned between the holding surface 74a and the surface 11a in the Z-axis direction.

[0161] Next, while supplying cutting fluid from the nozzle unit at a predetermined flow rate, the chuck table 72 is moved in the X-axis direction so that the lower end of the cutting blade 82 traces the division line 13. After cutting the workpiece 11 along one division line 13, the cutting unit 78 is moved by a predetermined amount in the Y-axis direction (i.e., indexed feed).

[0162] Then, other division lines 13 adjacent to the cut division line 13 in the Y-axis direction are cut in the same manner. After the workpiece 11 has been cut along all division lines 13 along the X-axis direction, the holding plate 74 is rotated by approximately 90 degrees. Then, similarly, the workpiece 11 is cut along all division lines 13 along the X-axis direction.

[0163] As a result, the workpiece 11 fixed to the sheet 17 is divided into multiple device chips 25. Figure 11(B) is a perspective view of one device chip 25. In the second embodiment, since the minute gap 11c between the surface 11a and the sheet 17 is reduced, the occurrence of cracks, chipping, etc. caused by the minute gap 11c can be reduced.

[0164] The processing device used to perform S50 is not limited to the cutting device 70. A laser processing device (not shown) may be used instead of the cutting unit 78. The laser processing device includes the chuck table 72 described above and a laser beam irradiation unit.

[0165] The laser beam irradiation unit includes a laser oscillator and a head unit. The laser oscillator has, for example, a crystal such as Nd:YAG as the laser medium.

[0166] By irradiating the crystal with excitation light from a light source such as a laser diode, the laser oscillator emits a pulsed laser beam having a wavelength (e.g., 1064 nm) that primarily penetrates the workpiece 11 (e.g., a silicon wafer).

[0167] The laser beam irradiation unit may use a nonlinear optical crystal such as CLBO (cesium lithium borate) to convert the pulsed laser beam emitted from the laser oscillator into harmonics. The laser beam, which is the fourth harmonic (wavelength 266 nm) with a wavelength of 1064 nm, is mainly absorbed by the workpiece 11 (e.g., a silicon wafer).

[0168] The pulsed laser beam has its direction of travel changed by a mirror located inside the head unit, and then, after being focused by a focusing lens also located inside the head unit, it is irradiated onto the workpiece 11 that is held by suction on the holding surface 74a.

[0169] If the laser beam has a wavelength that is mainly absorbed by the workpiece 11, the focal point of the laser beam is positioned on the back surface 11b, and the focal point and the chuck table 72 are moved relative to each other so that the focal point traces the planned division line 13.

[0170] Due to the relative movement of the focusing point and the workpiece 11, ablation is performed along the trajectory of the focusing point, forming laser-cut grooves that cut the workpiece 11. By forming laser-cut grooves along each planned division line 13, the workpiece 11 is divided into 25 device chip units.

[0171] Furthermore, if the laser beam has a wavelength that primarily penetrates the workpiece 11, by positioning the focal point of the laser beam between the back surface 11b and the front surface 11a and moving the focal point and the chuck table 72 relative to each other so that the focal point traces the planned division line 13, a relatively fragile modified region is formed along the movement path of the focal point.

[0172] After forming modified regions along each planned division line 13, the workpiece 11 is divided into multiple device chips 25 by applying an external force to it. The external force is applied, for example, by grinding the back surface 11b, applying ultrasonic vibration to the workpiece 11, or by expanding the sheet 17 radially.

[0173] By the way, in S50, a plasma processing device (not shown) may be used instead of a cutting device. When performing S50 with a plasma processing device, first the workpiece 11 is held by suction with an electrostatic chuck, and then, for example, the workpiece 11 is cut by plasma processing along each planned division line 13 using the Bosch process (i.e., plasma dicing is performed).

[0174] Furthermore, the structures, methods, etc., according to the above embodiments can be modified as appropriate without departing from the scope of the object of the present invention. For example, in the above embodiments, the sheet 17 and the frame 19 are integrated with the workpiece 11, but the frame 19 may be omitted and the sheet 17 and the workpiece 11 may be integrated.

[0175] For example, if no metal film is formed on the back surface 11b of the workpiece 11 and the semiconductor wafer is exposed, a sheet 17 may be fixed to the front surface 11a in order to thin the workpiece 11 by grinding the back surface 11b. In this case as well, the above steps S10 to S40 can be applied.

[0176] Furthermore, although the above description described a case where the adhesive device 2 has two different chuck tables (i.e., a first chuck table 12 and a second chuck table 52), the adhesive device 2 may have only one chuck table (either the first chuck table 12 or the second chuck table 52).

[0177] For example, if the adhesive device 2 has only a second chuck table 52, the second chuck table 52 is configured to be movable in the X-axis and Y-axis directions by a moving mechanism that includes a ball screw with a motor, screw shaft, etc., and is used in both the sheet fixing device 10 and the pressing device 50. [Explanation of Symbols]

[0178] 2: Adhesive device 4: Base, 4a, 4b, 4c: Cassette mounting area 6a, 6b, 6c: Cassette 8: Transport robot 10: Sheet fastening device 11: Workpiece (fixed object) 11a: Front surface (one side), 11b: Back surface (the other side), 11c: Gap 12: First chuck table, 12a: Holding surface, 12b: Heating element 13: Planned splitting line, 15: Device 14: Frame support base, 14a: Suction port, 16: Chamber 17: Sheet, 17a: Roll 18: Pressure roller 19: Frame, 19a: Opening, 21: Frame unit 20: Frame unit forming apparatus 22: Seat support base 23: Workpiece unit (workpiece attachment unit), 25: Device chip (chip) 24: Frame support base, 24a: Suction port, 24b: Heating element 26a, 26b: Feed rollers, 26c: Rotating shaft 28: Cutting unit, 28a: Rotating shaft, 28b: Arm, 28c: Cutting blade 29: Pressure roller 30: Frame supply unit, 32: Frame stocker 34: First conveying device, 34a: Suction unit, 34b: Moving block 44: Second transport device, 44a: Suction unit, 44b: Moving block 46: Third transport device, 46a: Suction unit, 46b: Moving block 50: Pressing device 52: Second chuck table (table), 52a: Holding surface, 52b: Heating element 54: Chamber (cover component) 54a: Seal ring, 54b: Internal space, 54c: Height, 54d: Opening 56: Pipe section, 56a: On / off valve, 56b: Pressure control valve 58: Compressed air supply source, 58a: Air 60a: Guide rail, 60b: Pusher 62: Controller, 62a: Processor, 62b: Memory 70: Cutting device, 72: Chuck table 72a: Frame support, 72b: Motor, 72c: Opening 74: Holding plate, 74a: Holding surface, 76: Imaging unit 78: Cutting unit, 80: Spindle, 82: Cutting blade P1: High position, P2: Low position P A :1st position, PB : Position 2

Claims

1. A method for fixing a sheet to one side of an object to be fixed, The sheet is fixed to one side of the object to be fixed to form an object unit, After the formation of the object to be fixed, the object to be fixed is supported on a table such that the other side of the object, which is opposite to the one side of the object to be fixed, is exposed. After the formation of the object to be fixed, at least the object to be fixed within the object to be fixed is covered with a cover member. The object to be fixed is supported by the table, and after the object to be fixed is covered with the cover member, the pressure in the internal space of the cover member covering the object to be fixed is made higher than the pressure in the external space of the cover member. A method for fixing a sheet, characterized by comprising the following features.

2. The sheet fixing method according to claim 1, characterized in that when the pressure in the internal space of the cover member is made higher than the pressure in the external space of the cover member, gas is supplied to the internal space of the cover member, thereby pressing the object to be fixed against the sheet with the gas.

3. The sheet is a heat-sealable sheet that does not have an adhesive layer made of an adhesive agent, but has a base layer. The sheet fixing method according to claim 1, characterized in that when forming the object to be fixed unit, the base material layer is heated and the heat-pressed sheet is heat-pressed onto one side of the object to be fixed.

4. The sheet fixing method according to any one of claims 1 to 3, characterized in that, when the pressure in the internal space of the cover member is made higher than the pressure in the external space of the cover member, the sheet to be fixed to the object of the object to be fixed unit is heated, and the pressure in the internal space of the cover member is made higher than the pressure in the external space of the cover member.

5. The sheet fixing method according to claim 4, characterized in that, when the pressure in the internal space of the cover member is to be higher than the pressure in the external space of the cover member, the sheet is held in place by the table by suction while the pressure in the internal space of the cover member is to be higher than the pressure in the external space of the cover member.

6. The method for fixing a sheet according to any one of claims 1 to 3, characterized in that when forming the object to be fixed unit, the sheet is fixed to an annular frame having an opening in the radial center and to one surface of the object to be fixed, and the object to be fixed, the frame and the sheet are integrated with the object to be fixed in place at the opening to form the object to be fixed unit.

7. A method for manufacturing chips, comprising fixing a sheet to one side of an object to be fixed, and then dividing the object to be fixed into a plurality of chips, The sheet is fixed to one side of the object to be fixed to form an object unit, After the formation of the object to be fixed, the object to be fixed is supported on a table such that the other side of the object, which is opposite to the one side of the object to be fixed, is exposed. After the formation of the object to be fixed, at least the object to be fixed within the object to be fixed is covered with a cover member. The object to be fixed is supported by the table, and after the object to be fixed is covered with the cover member, the pressure in the internal space of the cover member covering the object to be fixed is made higher than the pressure in the external space of the cover member. After increasing the pressure in the internal space of the cover member to a level higher than the pressure in the external space of the cover member, the material fixed to the sheet is divided into multiple chips, A method for manufacturing chips, characterized by comprising the following features.

8. A pressing device for pressing an object to be fixed onto a sheet in order to fix the sheet to one side of the object to be fixed, In a fixed object unit to which the sheet is fixed to one surface, a table supports the fixed object unit such that the other surface of the fixed object located opposite to the one surface is exposed, A cover member is provided above the table and covers at least the object to be fixed among the object to be fixed units supported by the table, Equipped with, A pressing device characterized in that, with the cover member covering at least the object to be fixed, the pressure in the internal space of the cover member is made higher than the pressure in the external space of the cover member, thereby pressing the object to be fixed against the sheet.

Images