Laser processing equipment

Abstract

To provide a laser processing device capable of easily adjusting the power of a laser beam with which a wafer is irradiated.SOLUTION: A laser processing device 500 includes holding means 502 that holds a wafer 4, laser beam irradiating means 504 that irradiates a boundary portion 22 between a device region 18 of the wafer 4 and an outer peripheral surplus region 20 held by the holding means 502 with a laser beam LB, and moving means 506 that relatively moves the holding means 502 and the laser beam irradiating means 504. The laser beam irradiating means 504 includes an oscillator 510 that oscillates the laser beam LB, a condenser 512 that collects the laser beam LB oscillated by the oscillator 510, a beam splitter 516 that is arranged between the condenser 512 and the oscillator 510 and splits the plasma light P emitted from the region processed by the irradiation of the laser beam LB and leads to a branch path 514, and plasma light detection means 518 that is arranged in the branch path 514 and detects the plasma light P.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] The present invention relates to a laser processing apparatus that processes a wafer by irradiating it with a laser beam, the wafer having a device area formed on its surface by dividing a plurality of devices into sections by planned division lines, and a peripheral excess area surrounding the device area. [Background technology]

[0002] A wafer has on its surface a device region where a plurality of devices such as ICs and LSIs are partitioned by planned division lines, and a peripheral excess region surrounding the device region.The back surface of the wafer is ground to a desired thickness, and then the wafer is divided into individual device chips using a dicing machine and a laser processing machine, and each of the divided device chips is used in electrical equipment such as mobile phones and personal computers.

[0003] Since thinning a wafer makes it difficult to transport and further process the wafer, the applicant has proposed a technology in which the back surface corresponding to the device region is ground to form a ring-shaped reinforcing portion on the back surface corresponding to the peripheral excess region (see, for example, Patent Document 1).

[0004] When dividing the wafer into individual device chips, the ring-shaped reinforcing portion gets in the way, so the ring-shaped reinforcing portion is removed by irradiating a laser beam onto the boundary between the device region and the peripheral excess region. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-147231 Summary of the Invention [Problem to be solved by the invention]

[0006] However, additional processing such as coating the front or back surface of the wafer with a metal film or the like may be performed, which poses a problem that the power of the laser beam irradiated onto the wafer must be appropriately adjusted depending on the material of the wafer substrate and the material of the film coated on the wafer, which is troublesome and intolerable.

[0007] SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a laser processing apparatus that can easily adjust the power of a laser beam that is irradiated onto a wafer. [Means for solving the problem]

[0008] According to the present invention, the following laser processing apparatus is provided to solve the above-mentioned problems: that is, a laser processing apparatus for processing a wafer by irradiating it with a laser beam, the wafer having a device region on its surface where a plurality of devices are partitioned by planned division lines and a peripheral surplus region surrounding the device region, the apparatus comprising: holding means for holding the wafer; laser beam application means for irradiating a laser beam onto the boundary between the device region and the peripheral surplus region of the wafer held by the holding means; and moving means for relatively moving the holding means and the laser beam application means, the laser beam application means including an oscillator for emitting a laser beam, a condenser for condensing the laser beam oscillated by the oscillator, plasma light detection means for detecting plasma light emitted from the region processed by the irradiation of the laser beam, and power setting means for setting the power of the laser beam in accordance with the type of material selected by an operator. The front or rear surface of the wafer is coated with a metal film, and the power setting means sets the power of the laser beam according to the type of material of the wafer or metal film selected by the operator. A laser processing apparatus is provided. The apparatus preferably further comprises a beam splitter disposed between the collector and the oscillator for branching plasma light emitted from the region machined by the laser beam irradiation and directing it to a branch path, and the plasma light detection means is disposed in the branch path. It is preferable that an error be issued if the type of material identified based on the plasma light detected by the plasma light detection means differs from the type of material selected by the operator via the power setting means. A recess is formed on the back surface of the wafer corresponding to the device region, and a ring-shaped reinforcing portion is formed in a convex shape on the back surface of the wafer corresponding to the peripheral excess region, and the laser beam is preferably irradiated onto the base of the ring-shaped reinforcing portion. It is preferable that the irradiation of the laser beam be stopped when the plasma light detection means no longer detects plasma light.

[0009] The present invention also provides the following laser processing apparatus that solves the above-mentioned problems: a laser processing apparatus that processes a wafer by irradiating it with a laser beam, the wafer having a device region on its surface, the device region being partitioned by planned division lines and having a peripheral excess region surrounding the device region, The wafer processing apparatus comprises: a holding means for holding a wafer; a laser beam application means for applying a laser beam to a boundary portion between a device region and a peripheral excess region of the wafer held by the holding means; and a moving means for relatively moving the holding means and the laser beam application means; the laser beam application means includes an oscillator that oscillates a laser beam, a condenser that condenses the laser beam oscillated by the oscillator, plasma light detection means that detects plasma light emitted from the region that has been processed by irradiating the laser beam, and power setting means that sets the power of the laser beam in accordance with the type of material selected by an operator; The laser processing device is provided such that, if the type of material identified based on the plasma light detected by the plasma light detection means differs from the type of material selected by the operator via the power setting means, an error is issued. It is desirable to further include a beam splitter disposed between the condenser and the oscillator for branching plasma light emitted from the region machined by the irradiation of the laser beam and directing it to a branch path, and the plasma light detection means is disposed in the branch path. Preferably, the front or back surface of the wafer is coated with a metal film, and the power setting means sets the power of the laser beam in accordance with the type of material of the wafer or metal film selected by the operator. .cormorant A recess is formed on the back surface of the wafer corresponding to the device region, and a ring-shaped reinforcing portion is formed in a convex shape on the back surface of the wafer corresponding to the peripheral excess region, and the laser beam is preferably irradiated onto the base of the ring-shaped reinforcing portion. It is desirable to stop irradiating the laser beam when the plasma light detection means no longer detects plasma light. [Effects of the Invention]

[0010] The laser processing apparatus of the present invention is a laser processing apparatus that processes a wafer by irradiating it with a laser beam, the wafer having a device region on its surface where a plurality of devices are partitioned by planned division lines and a peripheral surplus region surrounding the device region, and is equipped with holding means for holding the wafer, laser beam application means for irradiating a laser beam onto the boundary between the device region and the peripheral surplus region of the wafer held by the holding means, and moving means for relatively moving the holding means and the laser beam application means, the laser beam application means including an oscillator that oscillates a laser beam, a condenser that condenses the laser beam oscillated by the oscillator, plasma light detection means that detects plasma light emitted from the region processed by irradiating the laser beam, and power setting means that sets the power of the laser beam in accordance with the type of material selected by an operator. The front or rear surface of the wafer is coated with a metal film, and the power setting means sets the power of the laser beam according to the type of material of the wafer or metal film selected by the operator. Therefore, the power of the laser beam irradiated onto the wafer can be easily adjusted based on the detection result of the plasma light emitted from the region processed by the irradiation of the laser beam. The laser processing apparatus of the present invention is a laser processing apparatus for processing a wafer by irradiating a laser beam onto the wafer, the wafer having a device region on the surface of which a plurality of devices are defined by division lines and which has a peripheral surplus region surrounding the device region, the apparatus comprising: holding means for holding the wafer; laser beam application means for irradiating a laser beam onto a boundary between the device region and the peripheral surplus region of the wafer held by the holding means; and moving means for relatively moving the holding means and the laser beam application means, the laser beam application means comprising: an oscillator for emitting a laser beam; a plasma light detection means for detecting plasma light emitted from the region processed by the irradiation of the laser beam; and a power setting means for setting the power of the laser beam in accordance with the type of material selected by the operator. If the type of material identified based on the plasma light detected by the plasma light detection means differs from the type of material selected by the operator via the power setting means, an error is issued. Therefore, the power of the laser beam irradiated onto the wafer can be easily adjusted based on the detection result of the plasma light emitted from the region processed by the irradiation of the laser beam. [Brief explanation of the drawings]

[0011] [Figure 1]1 is a perspective view of a processing unit including a laser processing device configured according to the present invention; [Figure 2] FIG. 2 is a perspective view of a wafer to be processed by the processing unit shown in FIG. [Figure 3] FIG. 2 is a perspective view of a wafer cassette table and the like shown in FIG. [Figure 4] FIG. 2 is a perspective view of the hand shown in FIG. 1 . [Figure 5] FIG. 2 is a perspective view of a frame receiving means and the like shown in FIG. [Figure 6] (a) is a perspective view of the tape application means, etc. when the frame table shown in Figure 1 is in a lowered position, (b) is a perspective view of the tape application means, etc. when the frame table shown in Figure 1 is in an raised position. [Figure 7] FIG. 2 is an exploded perspective view of the tape pressing means shown in FIG. 1. [Figure 8] FIG. 10 is a cross-sectional view showing a state in which the pressure roller starts to press the tape in the tape pressing step. [Figure 9] FIG. 10 is a cross-sectional view showing a state in which pressing of the tape by the pressing roller has been completed in the tape pressing step. [Figure 10] FIG. 2 is a perspective view of the reinforcement portion removing means shown in FIG. 1. [Figure 11] (a) A cross-sectional view of the frame support part when the strong permanent magnet of the temporary placement table shown in Figure 1 is in an elevated position, (b) A cross-sectional view of the frame support part when the strong permanent magnet of the temporary placement table shown in Figure 1 is in a lowered position. [Figure 12] 2(a) is a perspective view of the holding means of the laser processing apparatus shown in FIG. 1, and FIG. 2(b) is a perspective view of the first lift table shown in FIG. 2(a) as seen from below. [Figure 13] FIG. 2 is a block diagram showing the configuration of a laser beam application means. [Figure 14] (a) A graph showing an example of a signal input to the control means, and (b) a table showing the relationship between the wavelength of the plasma light, the material of the area subjected to laser processing, and the power of the laser beam. [Figure 15] FIG. 10 is a schematic diagram showing a state in which a laser beam is irradiated onto the base of the wafer in the reinforcing portion removal step. [Figure 16] FIG. 2 is a perspective view of a separation portion of the reinforcement-removing means shown in FIG. 1; [Figure 17] FIG. 10 is a schematic diagram showing a state in which the reinforcing portion is being separated from the wafer in the reinforcing portion removing step. [Figure 18] 2 is a perspective view of a discarding portion of the reinforcing portion removing means shown in FIG. 1. FIG. [Figure 19] FIG. 2 is a perspective view of a reversing mechanism of the ring-free unit carrying-out means shown in FIG. [Figure 20] 2 is a perspective view of a ring-free unit supporting portion and a pushing portion of the ring-free unit carrying-out means shown in FIG. 1. FIG. [Figure 21] FIG. 10 is a perspective view showing a state in which a ring-less unit accommodating step is being performed. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a laser processing apparatus configured according to the present invention will now be described with reference to the drawings, taking as an example a processing unit including the laser processing apparatus of the present invention.

[0013] Referring to FIG. 1, the processing unit, generally designated by the reference numeral 2, comprises a wafer cassette table 8 on which a wafer cassette 6 containing a plurality of wafers is placed, a wafer carrying-out means 10 for carrying out wafers from the wafer cassette 6 placed on the wafer cassette table 8, and a wafer table 12 for supporting the front side of the wafer carried out by the wafer carrying-out means 10.

[0014] FIG. 2 shows a wafer 4 to be processed by the processing unit 2. The front surface 4a of the wafer 4 has a device region 18, in which a plurality of devices 14, such as ICs and LSIs, are partitioned by grid-like dividing lines 16, and a peripheral surplus region 20 surrounding the device region 18. In FIG. 2, a boundary 22 between the device region 18 and the peripheral surplus region 20 is shown by a two-dot chain line for convenience, but in reality, there is no line indicating the boundary 22. A circular recess 23 is formed on the back surface 4b of the wafer 4 corresponding to the device region 18, and a ring-shaped reinforcing portion 24 is formed in a convex shape on the back surface 4b of the wafer 4 corresponding to the peripheral surplus region 20, and the thickness of the peripheral surplus region 20 is greater than the thickness of the device region 18. In addition, a notch 26 indicating the crystal orientation is formed on the periphery of the wafer 4. The front surface 4a or the back surface 4b of the wafer 4 may be coated with a metal film, such as aluminum or copper.

[0015] 3, a cassette 6 accommodates a plurality of wafers 4 spaced apart in the vertical direction with their surfaces 4a facing upward. The wafer cassette table 8 in the illustrated embodiment has a top plate 28 on which the cassette 6 is placed, and a support plate 30 that supports the top plate 28. The top plate 28 is movable up and down, and an elevator means may be provided to raise and lower the top plate 28 to position it at any height.

[0016] Continuing the explanation with reference to FIG. 3, the wafer unloading means 10 includes a Y-axis movable member 32 that is movable in the Y-axis direction indicated by the arrow Y in FIG. 3, and a Y-axis feed means 34 that moves the Y-axis movable member 32 in the Y-axis direction. The Y-axis feed means 34 includes a ball screw 36 that is connected to the lower end of the Y-axis movable member 32 and extends in the Y-axis direction, and a motor 38 that rotates the ball screw 36. The Y-axis feed means 34 converts the rotational motion of the motor 38 into linear motion using the ball screw 36 and transmits it to the Y-axis movable member 32, thereby moving the Y-axis movable member 32 in the Y-axis direction along a pair of guide rails 40 that extend in the Y-axis direction. Note that the X-axis direction indicated by the arrow X in FIG. 3 is a direction perpendicular to the Y-axis direction, and the Z-axis direction indicated by the arrow Z in FIG. 3 is an up-down direction perpendicular to the X-axis and Y-axis directions. The XY plane defined by the X-axis and Y-axis directions is substantially horizontal.

[0017] 3, the wafer carrying-out means 10 of the illustrated embodiment includes a transfer arm 42 and a hand 44 disposed at the tip of the transfer arm 42, which supports the back surface 4b of the wafer 4 housed in the wafer cassette 6 and turns the wafer 4 upside down. The transfer arm 42 is provided on the upper surface of the Y-axis movable member 32 and is driven by an appropriate drive source (not shown), such as an air drive source or an electric drive source. This drive source drives the transfer arm 42 to position the hand 44 at any position in each of the X-axis, Y-axis, and Z-axis directions and to turn the hand 44 upside down.

[0018] Explaining with reference to Fig. 4, the hand 44 is preferably a Bernoulli pad that generates negative pressure by jetting air and supports the wafer 4 without contact. The hand 44 in the illustrated embodiment is C-shaped overall, and one side of the hand 44 is formed with a plurality of air jets 46 connected to a compressed air supply source (not shown). A plurality of guide pins 48 are attached to the outer periphery of the hand 44 at intervals in the circumferential direction. Each guide pin 48 is configured to be movable radially of the hand 44.

[0019] 3 and 4, the wafer unloading means 10 positions the hand 44 on the back surface 4b side (underside) of the wafer 4 in the wafer cassette 6 placed on the wafer cassette table 8, and then ejects compressed air from the air ejection ports 46 of the hand 44 to generate negative pressure on one side of the hand 44 by the Bernoulli effect, causing the hand 44 to suction-support the wafer 4 from the back surface 4b side without contact. The horizontal movement of the wafer 4 suction-supported by the hand 44 is regulated by each guide pin 48. The wafer unloading means 10 then moves the Y-axis movable member 32 and the transfer arm 42 to unload the wafer 4 suction-supported by the hand 44 from the wafer cassette 6.

[0020] 4, the wafer carrying-out means 10 of the illustrated embodiment is equipped with a notch detection means 50 that detects the position of the notch 26 of the wafer 4. The notch detection means 50 may be configured to include, for example, a light-emitting element 52 and a light-receiving element 54 that are spaced apart from each other in the vertical direction, and a drive source (not shown) that rotates at least one of the guide pins 48 of the hand 44.

[0021] The light-emitting element 52 and the light-receiving element 54 can be attached to the Y-axis movable member 32 or the transport path via an appropriate bracket (not shown). When the guide pin 48 is rotated by the drive source, the rotation of the guide pin 48 causes the wafer 4 supported by suction by the hand 44 to rotate. In order to reliably transmit the rotation from the guide pin 48 to the wafer 4, it is preferable that the outer circumferential surface of the guide pin 48, which is rotated by the drive source, is formed from an appropriate synthetic rubber.

[0022] The notch detection means 50 can detect the position of the notch 26 by rotating the wafer 4 via the guide pin 48 using a drive source while the wafer 4 is supported by suction with the hand 44 and the outer periphery of the wafer 4 is positioned between the light emitting element 52 and the light receiving element 54. This makes it possible to adjust the orientation of the wafer 4 to any desired orientation.

[0023] As shown in Figure 3, the wafer table 12 is disposed adjacent to the wafer carrying-out means 10. The wafer table 12 in the illustrated embodiment includes an annular support portion 56 that supports the peripheral excess region 20 of the wafer 4 and keeps the portion inside the peripheral excess region 20 out of contact, and a frame support portion 58 that is disposed on the outer periphery of the annular support portion 56 and supports a frame 64 (see Figure 5), which will be described later. A plurality of suction holes 60 are formed in the upper surface of the annular support portion 56 and are spaced apart in the circumferential direction, and each suction hole 60 is connected to a suction means (not shown). A portion of the wafer table 12 radially inward of the annular support portion 56 forms a circular recess 62 that is recessed downward.

[0024] When the hand 44 is turned 180° to invert the wafer 4 and place the wafer 4 on the wafer table 12 with the front surface 4a of the wafer 4 facing downward, the peripheral excess region 20 of the wafer 4 is supported by the annular support portion 56 and the device region 18 of the wafer 4 is located in the recess 62. Therefore, even if the wafer 4 is placed on the wafer table 12 with the front surface 4a on which the devices 14 are formed facing downward, the devices 14 and the wafer table 12 do not come into contact with each other, preventing damage to the devices 14. Furthermore, after the wafer table 12 supports the peripheral excess region 20 with the annular support portion 56, it activates the suction means to generate suction force in each suction hole 60 to suction-hold the peripheral excess region 20, thereby preventing the wafer 4 from shifting position.

[0025] Referring to Figure 5, the processing unit 2 further includes a frame accommodating means 66 for accommodating multiple ring-shaped frames 64 each having an opening 64a for accommodating a wafer 4, a frame unloading means 68 for unloading the frames 64 from the frame accommodating means 66, and a frame table 70 for supporting the frames 64 unloaded by the frame unloading means 68.

[0026] As shown in FIG. 5, the frame accommodating means 66 of the illustrated embodiment includes a housing 72, a lift plate 74 arranged within the housing 72 so as to be movable up and down, and a lifting means (not shown) for raising and lowering the lift plate 74. In FIG. 5, a Z-axis guide member 78 extending in the Z-axis direction is arranged on the side surface of the housing 72 at the rear in the X-axis direction. The lift plate 74 is supported by the Z-axis guide member 78 so as to be movable up and down, and the lifting means for raising and lowering the lift plate 74 is arranged inside the Z-axis guide member 78. The lifting means may include, for example, a ball screw connected to the lift plate 74 and extending in the Z-axis direction, and a motor for rotating the ball screw. In FIG. 5, a door 76 with a handle 76a is provided on the side surface of the housing 72 at the front in the X-axis direction. In the frame accommodating means 66, the frame 64 can be accommodated inside the housing 72 by gripping the handle 76a and opening the door 76. An opening 80 is provided at the top end of the housing 72 .

[0027] 5, frames 64 made of a magnetic material are stacked on the upper surface of a lifting plate 74 and accommodated inside the housing 72. The uppermost frame 64 of the stacked frames 64 is carried out by a frame carrying-out means 68 through an opening 80 in the housing 72. Furthermore, when a frame 64 is carried out through the opening 80, the frame accommodating means 66 appropriately raises the lifting plate 74 using the lifting means, and positions the uppermost frame 64 at a position where it can be carried out by the frame carrying-out means 68.

[0028] 5, frame carry-out means 68 includes an X-axis guide member 82 fixed to an appropriate bracket (not shown) and extending in the X-axis direction, an X-axis movable member 84 supported by X-axis guide member 82 so as to be movable in the X-axis direction, an X-axis feed means (not shown) for moving X-axis movable member 84 in the X-axis direction, a Z-axis movable member 86 supported by X-axis movable member 84 so as to be movable in the Z-axis direction, and a Z-axis feed means (not shown) for moving Z-axis movable member 86 in the Z-axis direction. The X-axis feed means of frame carry-out means 68 may be configured to include a ball screw connected to X-axis movable member 84 and extending in the X-axis direction, and a motor for rotating the ball screw, and the Z-axis feed means may be configured to include a ball screw connected to Z-axis movable member 86 and extending in the Z-axis direction, and a motor for rotating the ball screw.

[0029] The Z-axis movable member 86 of the frame carry-out means 68 has a holding portion 88 that holds the frame 64. In the illustrated embodiment, the holding portion 88 has a rectangular base plate 90 and a plurality of suction pads 92 provided on the underside of the base plate 90, and each suction pad 92 is connected to suction means (not shown).

[0030] The frame ejection means 68 holds the top frame 64 housed in the frame storage means 66 by suction using the suction pad 92 of the holding portion 88, and then moves the X-axis movable member 84 and the Z-axis movable member 86 to eject the top frame 64 held by suction from the frame storage means 66.

[0031] 5, the frame table 70 is supported by a Z-axis guide member 94 so as to be able to move up and down between a lowered position indicated by a solid line and an upper position indicated by a two-dot chain line. An appropriate drive source (for example, an air drive source or an electric drive source) is attached to the Z-axis guide member 94 for raising and lowering the frame table 70 between the lowered position and the upper position. The frame table 70 is designed to receive the frame 64 carried out by the frame carry-out means 68 at the lowered position.

[0032] As shown in Figures 1 and 5, the processing unit 2 includes a tape application means 98 (see Figure 1) that is arranged above the frame table 70 and applies tape 96 to the frame 64, a tape-attached frame transport means 100 (see Figure 5) that transports the frame 64 with the tape 96 attached (hereinafter sometimes referred to as the "tape-attached frame 64'") to the wafer table 12 and positions the opening 64a of the frame 64 over the back surface 4b of the wafer 4 supported on the wafer table 12, thereby placing the tape-attached frame 64' on the wafer table 12, and a tape pressing means 102 (see Figure 1) that presses the tape 96 of the tape-attached frame 64' onto the back surface 4b of the wafer 4.

[0033] Referring to Figure 6, the tape application means 98 of the illustrated embodiment includes a roll tape support section 104 that supports a roll tape 96R on which unused tape 96 is wound, a tape winding section 106 that winds up the used tape 96, a tape pulling section 108 that pulls out the tape 96 from the roll tape 96R, a crimping section 110 that crimps the pulled-out tape 96 to the frame 64, and a cutting section 112 that cuts off the tape 96 that protrudes beyond the outer periphery of the frame 64 along the frame 64.

[0034] 6, the roll tape support unit 104 includes a support roller 114 supported by an appropriate bracket (not shown) so as to be rotatable about an axis extending in the X-axis direction. The support roller 114 supports a roll tape 96R that is wound into a cylindrical shape and has a release paper 116 attached to the adhesive surface of the tape 96 to protect the adhesive surface of the tape 96.

[0035] The tape winding unit 106 includes a winding roller 118 supported by an appropriate bracket (not shown) so as to be rotatable about an axis extending in the X-axis direction, and a motor (not shown) that rotates the winding roller 118. As shown in Fig. 6, the tape winding unit 106 rotates the winding roller 118 with the motor, thereby winding up the used tape 96, which has a circular opening 120 that corresponds to the portion attached to the frame 64.

[0036] Continuing the explanation with reference to Figure 6, the tape pull-out section 108 includes a pull-out roller 122 arranged below the support roller 114 of the roll tape support section 104, a motor (not shown) that rotates the pull-out roller 122, and a driven roller 124 that rotates in conjunction with the rotation of the pull-out roller 122. The tape pull-out section 108 rotates the driven roller 124 together with the pull-out roller 122 using the motor, thereby pulling out the tape 96 sandwiched between the pull-out roller 122 and the driven roller 124 from the roll tape 96R.

[0037] The release paper 116 is peeled off from the tape 96 that has passed between the pull-out roller 122 and the driven roller 124, and the peeled release paper 116 is taken up by a release paper take-up unit 126. In the illustrated embodiment, the release paper take-up unit 126 has a release paper take-up roller 128 that is arranged above the driven roller 124, and a motor (not shown) that rotates the release paper take-up roller 128. In addition, the tape 96 from which the release paper 116 has been peeled off is guided to the take-up roller 118 via a guide roller 130 that is arranged at a distance from the pull-out roller 122 in the Y-axis direction.

[0038] The pressure bonding unit 110 includes a pressure roller 132 that is arranged to be movable in the Y-axis direction, and a Y-axis feed means (not shown) that moves the pressure roller 132 in the Y-axis direction. The Y-axis feed means of the pressure bonding unit 110 can be configured from an appropriate drive source (for example, an air drive source or an electric drive source).

[0039] 6, cutting unit 112 includes a Z-axis guide member 134 fixed to an appropriate bracket (not shown) and extending in the Z-axis direction, a Z-axis movable member 136 supported by Z-axis guide member 134 so as to be movable in the Z-axis direction, and a Z-axis feed means (not shown) that moves Z-axis movable member 136 in the Z-axis direction. The Z-axis feed means of cutting unit 112 may be configured to include a ball screw connected to Z-axis movable member 136 and extending in the Z-axis direction, and a motor that rotates this ball screw.

[0040] Cutting section 112 also includes a motor 138 fixed to the underside of the tip of Z-axis movable member 136, and an arm piece 140 that is rotated by motor 138 about an axis extending in the Z-axis direction. First and second hanging pieces 142a, 142b are attached to the underside of arm piece 140 at a distance from each other. A circular cutter 144 is supported on first hanging piece 142a so as to be rotatable about an axis perpendicular to the Z-axis direction, and a presser roller 146 is supported on second hanging piece 142b so as to be rotatable about an axis perpendicular to the Z-axis direction.

[0041] Before the frame table 70, which has received the frame 64 from the frame discharge means 68, is moved from the lowered position (the position shown in FIG. 6(a)) to the raised position (the position shown in FIG. 6(b)), the tape application means 98 draws out the unused tape 96 using the draw-out roller 122 and driven roller 124. Then, the frame table 70 is positioned at the raised position to an extent that the pressure roller 132 of the pressure bonding unit 110 can press the tape 96 against the frame 64, and the pressure roller 132 is brought into contact with the frame 64 via the tape 96. Then, the pressure roller 132 rolls in the Y-axis direction while pressing the adhesive surface of the tape 96 against the frame 64 with the pressure roller 132. This allows the tape 96 drawn out from the roll tape 96R by the tape draw-out unit 108 to be pressure-bonded to the frame 64.

[0042] After the tape 96 has been pressed against the frame 64, the tape application means 98 lowers the Z-axis movable member 136 of the cutting unit 112 using the Z-axis feed means, pressing the cutter 144 against the tape 96 on the frame 64 and pressing the frame 64 from above the tape 96 with the pressure roller 146. Next, the motor 138 rotates the arm piece 140, moving the cutter 144 and pressure roller 146 in a circular motion along the frame 64. This allows the tape 96 that extends beyond the outer periphery of the frame 64 to be cut along the frame 64. In addition, because the pressure roller 146 presses the frame 64 from above the tape 96, displacement of the frame 64 and the tape 96 while cutting the tape 96 is prevented. Then, after the frame table 70 is lowered, the used tape 96, now with the circular opening 120 corresponding to the portion of the tape 96 that was attached to the frame 64, is taken up by the tape take-up unit 106.

[0043] 5, the tape-attached frame transport stage 100 includes a Y-axis guide member 148 fixed to an appropriate bracket (not shown) and extending in the Y-axis direction, a Y-axis movable member 150 supported by the Y-axis guide member 148 so as to be movable in the Y-axis direction, a Y-axis feed means (not shown) for moving the Y-axis movable member 150 in the Y-axis direction, a Z-axis movable member 152 supported by the Y-axis movable member 150 so as to be movable in the Z-axis direction, and a Z-axis feed means (not shown) for moving the Z-axis movable member 152 in the Z-axis direction. The Y-axis feed means of the tape-attached frame transport stage 100 may be configured to include a ball screw connected to the Y-axis movable member 150 and extending in the Y-axis direction, and a motor for rotating the ball screw, and the Z-axis feed means may be configured to include a ball screw connected to the Z-axis movable member 152 and extending in the Z-axis direction, and a motor for rotating the ball screw.

[0044] The Z-axis movable member 152 of the tape-attached frame transport means 100 has a holding portion 154 that holds the tape-attached frame 64'. In the illustrated embodiment, the holding portion 154 has a rectangular base plate 156 and a plurality of suction pads 158 provided on the underside of the base plate 156, and each suction pad 158 is connected to suction means (not shown).

[0045] The tape-attached frame transport means 100 suction-holds the upper surface of the tape-attached frame 64' supported on the frame table 70 with the adhesive side of the tape 96 facing downwards using each suction pad 158 of the holding portion 154, and by moving the Y-axis movable member 150 and the Z-axis movable member 152, transports the tape-attached frame 64' held by suction by the holding portion 154 from the frame table 70 to the wafer table 12, and places the tape-attached frame 64' on the wafer table 12 by positioning the opening 64a of the frame 64 on the back surface 4b of the wafer 4 supported on the wafer table 12.

[0046] The tape pressing means 102 will be described with reference to Figures 7 to 9. As shown in Figure 7, the tape pressing means 102 includes an upper chamber 160 disposed above the wafer table 12, a lower chamber 162 accommodating the wafer table 12, an elevation mechanism 164 that raises and lowers the upper chamber 160 to create a closed state in which it is in contact with the lower chamber 162 and an open state in which it is separated from the lower chamber 162, a vacuum section 166 that evacuates the upper chamber 160 and the lower chamber 162 in the closed state, and an atmosphere opening section 168 that opens the upper chamber 160 and the lower chamber 162 to the atmosphere.

[0047] 7, the upper chamber 160 in the illustrated embodiment includes a circular top plate 170 and a cylindrical side wall 172 that hangs down from the periphery of the top plate 170. An elevation mechanism 164, which may be composed of an appropriate actuator such as an air cylinder, is attached to the upper surface of the top plate 170. In the storage space defined by the lower surface of the top plate 170 and the inner peripheral surface of the side wall 172, there are disposed a pressure roller 174 for pressing the tape 96 of the tape-attached frame 64' against the back surface 4b of the wafer 4 supported on the wafer table 12, a support piece 176 for rotatably supporting the pressure roller 174, and a Y-axis feed means 178 for moving the support piece 176 in the Y-axis direction.

[0048] Y-axis feed means 178 has a ball screw 180 that is connected to support piece 176 and extends in the Y-axis direction, and a motor 182 that rotates ball screw 180. Y-axis feed means 178 converts the rotational motion of motor 182 into linear motion using ball screw 180 and transmits the linear motion to support piece 176, moving support piece 176 along a pair of guide rails 184 that extend in the Y-axis direction.

[0049] 7, the lower chamber 162 has a cylindrical side wall 186, with the upper part of the side wall 186 open and the lower part of the side wall 186 closed. A connection opening 188 is formed in the side wall 186. A vacuum part 166, which may be constituted by an appropriate vacuum pump, is connected to the connection opening 188 via a flow path 190. The flow path 190 is provided with an atmosphere opening part 168, which may be constituted by an appropriate valve that can open the flow path 190 to the atmosphere.

[0050] With the tape 96 of the tape-attached frame 64' positioned on the back surface 4b of the wafer 4 supported on the wafer table 12, the tape pressing means 102 lowers the upper chamber 160 using the lifting mechanism 164, bringing the lower end of the side wall 172 of the upper chamber 160 into contact with the upper end of the side wall 186 of the lower chamber 162, thereby closing the upper chamber 160 and the lower chamber 162 and bringing the pressure roller 174 into contact with the tape-attached frame 64'.

[0051] Next, the tape pressing means 102 operates the vacuum pump that constitutes the vacuum section 166 with the valve that constitutes the atmospheric release section 168 closed, and creates a vacuum inside the upper chamber 160 and the lower chamber 162.After that, as shown in Figures 8 and 9, the Y-axis feed means 178 rolls the pressure roller 174 in the Y-axis direction, thereby pressing the tape 96 onto the back surface 4b of the wafer 4 to generate a frame unit U.

[0052] When the tape 96 is pressed onto the back surface 4b of the wafer 4 by the pressure roller 174, a small gap is formed between the wafer 4 and the tape 96 at the base of the ring-shaped reinforcing portion 24, but because the wafer 4 and the tape 96 are pressed together with the interior of the upper chamber 160 and the lower chamber 162 held in a vacuum, the pressure in the small gap between the wafer 4 and the tape 96 is lower than atmospheric pressure, and when the air vent portion 168 is opened after the tape 96 has been pressed together, the atmospheric pressure presses the tape 96 against the wafer 4. This eliminates the gap between the wafer 4 and the tape 96 at the base of the reinforcing portion 24, and the tape 96 comes into close contact with the back surface 4b of the wafer 4 along the base of the reinforcing portion 24.

[0053] As shown in Figures 1 and 10, the processing unit 2 further includes a frame unit carrying-out means 192 that carries out from the wafer table 12 a frame unit U in which the tape 96 of the tape-attached frame 64' and the back surface 4b of the wafer 4 have been pressed together by the tape pressing means 102; a reinforcing portion removing means 194 that cuts and removes the ring-shaped reinforcing portion 24 from the wafer 4 of the frame unit U carried out by the frame unit carrying-out means 192; a ring-less unit carrying-out means 196 (see Figure 1) that carries out from the reinforcing portion removing means 194 the ring-less unit from which the ring-shaped reinforcing portion 24 has been removed; and a frame cassette table 200 (see Figure 1) on which a frame cassette 198 containing the ring-less unit carried out by the ring-less unit carrying-out means 196 is placed.

[0054] As shown in FIG. 10, the frame unit carrying-out means 192 of the illustrated embodiment comprises a frame unit holding section 202 including a wafer holding section 202a that holds the wafer 4 while exposing all or part of the outer periphery of the wafer 4 and a frame holding section 202b that holds the frame 64, and a transport section 206 that transports the frame unit holding section 202 to the temporary placement table 204.

[0055] The wafer holding portion 202a of the frame unit holding portion 202 includes a circular base plate 208 and a suction piece 210 attached to the underside of the base plate 208. A plurality of suction holes (not shown) are formed in the underside of the suction piece 210, and each suction hole is connected to suction means (not shown). The shape of the suction piece 210 may be, for example, a circle smaller than the diameter of the wafer 4. The frame holding portion 202b includes a plurality of protruding pieces 212 (four in the illustrated embodiment) that protrude radially outward from the periphery of the base plate 208 of the wafer holding portion 202a at intervals in the circumferential direction, and suction pads 214 attached to the undersides of the protruding pieces 212, and each suction pad 214 is connected to suction means (not shown).

[0056] The transport unit 206 includes an X-axis guide member 216 fixed to an appropriate bracket (not shown) and extending in the X-axis direction, an X-axis movable member 218 supported by the X-axis guide member 216 so as to be movable in the X-axis direction, an X-axis feed mechanism (not shown) for moving the X-axis movable member 218 in the X-axis direction, a Z-axis movable member 220 supported by the X-axis movable member 218 so as to be movable in the Z-axis direction, a Z-axis feed mechanism (not shown) for moving the Z-axis movable member 220 in the Z-axis direction, a Y-axis movable member 222 supported by the Z-axis movable member 220 so as to be movable in the Y-axis direction, and a Y-axis feed mechanism (not shown) for moving the Y-axis movable member 222 in the Y-axis direction. The base plate 208 of the wafer holder 202a is connected to the tip of the Y-axis movable member 222. Each of the X-axis, Y-axis, and Z-axis feed mechanisms of the transport unit 206 may include a ball screw and a motor for rotating the ball screw.

[0057] The frame unit carry-out means 192 further includes an imaging section 224 that images the outer periphery of the wafer 4 of the frame unit U held by the frame unit holding section 202, and an illumination section 400 that is disposed in a position facing the imaging section 224 and sandwiching the wafer 4. The imaging section 224 in the illustrated embodiment is disposed between the wafer table 12 and the temporary placement table 204, and images the outer periphery of the wafer 4 of the frame unit U held by the frame unit holding section 202 from below the wafer 4.

[0058] The frame unit unloading means 192 suction-holds the wafer 4 from the back surface 4b side (tape 96 side) with the suction pieces 210 of the wafer holding portion 202a, and suction-holds the frame 64 with the suction pads 214 of the frame holding portion 202b, and operates the transport portion 206 to unload the frame unit U held by the frame unit holding portion 202 from the wafer table 12. When the suction pieces 210 of the wafer holding portion 202a suction-hold the wafer 4, the entire back surface 4b side of the wafer 4 is not covered by the suction pieces 210, that is, there are portions of the back surface 4b of the wafer 4 that are not suctioned by the suction pieces 210, and all or part of the outer periphery of the wafer 4 is exposed.

[0059] Furthermore, the frame unit carry-out means 192 of the illustrated embodiment operates the transport unit 206 to measure the coordinates of at least three points on the outer periphery of the wafer 4 by using the imaging unit 224 to capture images of at least three locations on the exposed portion (portion not covered by the suction piece 210) of the outer periphery of the wafer 4 of the frame unit U held by the frame unit holding unit 202, and determines the central coordinates of the wafer 4 based on the coordinates of the three measured points. In the illustrated embodiment, since all or part of the outer periphery of the wafer 4 held by suction on the suction piece 210 is exposed, the exposed portion on the outer periphery of the wafer 4 is illuminated from above the wafer 4 by the illumination unit 400 and the exposed portion on the outer periphery of the wafer 4 is captured from below the wafer 4 by the imaging unit 224, thereby enabling the outline of the wafer 4 to be clearly imaged and the central coordinates of the wafer 4 to be accurately determined. Then, the frame unit carrying-out means 192 aligns the center of the wafer 4 with the center of the temporary placement table 204 and temporarily places the frame unit U on the temporary placement table 204 .

[0060] 10 , the temporary placement table 204 is disposed at a distance from the wafer table 12 in the X-axis direction. The temporary placement table 204 in the illustrated embodiment includes an annular support portion 226 that supports the outer peripheral surplus region 20 of the wafer 4 of the frame unit U and keeps the portion inside the outer peripheral surplus region 20 out of contact, and a frame support portion 228 that is disposed on the outer periphery of the annular support portion 226 and supports the frame 64. The frame support portion 228 includes a strong permanent magnet 402 having a stronger magnetic force than a permanent magnet 424 of a first lift table 420 described later, and a detachment portion 404 that detaches the frame magnetically attached to the strong permanent magnet 402.

[0061] As shown in FIG. 10 , the strong permanent magnets 402 are accommodated at the upper end of a frame body 406 of the frame support portion 228, spaced apart from one another in the circumferential direction. Referring to FIG. 11 , the strong permanent magnet 402 in the illustrated embodiment has a cylindrical main portion 402a whose upper end surface magnetically attaches to the frame, and an annular flange portion 402b extending radially outward from the lower end of the main portion 402a. The strong permanent magnet 402 is accommodated in an accommodation hole 406a of the frame body 406 and is movable up and down between a raised position shown in FIG. 11( a) and a lowered position shown in FIG. 11( b). As can be seen from FIG. 11 , in the raised position, the upper surface of the strong permanent magnet 402 is flush with the upper surface of the frame body 406, and in the lowered position, the upper surface of the strong permanent magnet 402 is located, for example, approximately 5 mm below the upper surface of the frame body 406. The frame body 406 is made of a non-magnetic material.

[0062] 11, a partition wall 408 is provided in the vertical middle of the accommodation hole 406a of the frame body 406, and this partition wall 408 divides the accommodation hole 406a of the frame body 406 into an upper accommodation chamber 410 that accommodates the strong permanent magnet 402 and a lower accommodation chamber 412 that accommodates the detachable part 404. A through opening 408a is formed in the center of the partition wall 408.

[0063] A protrusion 410a that protrudes radially inward is formed on the upper end side of the upper accommodating chamber 410. As shown in FIG. 11(a), when an upward force is applied to the strong permanent magnet 402 from the release portion 404, the upper end of the flange portion 402b of the strong permanent magnet 402 catches on the lower end of the protrusion 410a, and the strong permanent magnet 402 is positioned in a raised position. On the other hand, when a downward force is applied to the strong permanent magnet 402 from the release portion 404, the lower surface of the strong permanent magnet 402 comes into contact with the upper surface of the partition wall 408, and the strong permanent magnet 402 is positioned in a lowered position, as shown in FIG. 11(b). In addition, an upper opening 412a and a lower opening 412b are formed in the lower accommodating chamber 412, spaced apart in the vertical direction.

[0064] Continuing the explanation with reference to FIG. 11, the release portion 404 in the illustrated embodiment includes a rod 414 extending downward from the lower end of the strong permanent magnet 402 through the through-opening 408a, a piston 416 fixed to the lower end of the rod 414 and disposed in the lower storage chamber 412, a coil spring 418 disposed below the piston 416, and a compressed air supply source (not shown) connected to the upper opening 412a of the lower storage chamber 412.

[0065] In the detachment unit 404, the supply of compressed air from the compressed air supply source to the lower housing chamber 412 is stopped, and the piston 416 is pushed upward by the coil spring 418, thereby applying an upward force to the strong permanent magnet 402, raising the strong permanent magnet 402 relative to the frame body 406, and positioning the strong permanent magnet 402 at an elevated position where the strong permanent magnet 402 can magnetize the frame 64 placed on the frame support unit 228. In addition, the detachment unit 404 supplies compressed air from the compressed air supply source to the lower housing chamber 412 and pushes the piston 416 downward, thereby applying a downward force to the strong permanent magnet 402, lowering the strong permanent magnet 402 relative to the frame body 406, and positioning the strong permanent magnet 402 at a lowered position where the frame 64 placed on the frame support unit 228 can be detached from the strong permanent magnet 402. Note that pushing the piston 416 downward discharges air from the lower opening 412b.

[0066] As shown in FIG. 10, the upper surface of the annular support portion 226 of the temporary placement table 204 is formed with a plurality of suction holes 229 spaced apart in the circumferential direction, and each suction hole 229 is connected to a suction means (not shown). The annular support portion 226 is configured to be freely raised and lowered between an elevated position (position shown in FIG. 10) where the upper surface of the annular support portion 226 is flush with the upper surface of the frame support portion 228, and a lowered position where the upper surface of the annular support portion 226 is located, for example, approximately 5 to 10 mm below the upper surface of the frame support portion 228. The lifting means (not shown) for lifting and lowering the annular support portion 226 may be an appropriate actuator such as an air cylinder. A circular recess 230 is formed radially inward from the annular support portion 226, recessed downward. It is preferable that the frame support portion 228 of the temporary placement table 204 is equipped with a heater (not shown), and the tape 96 of the frame unit U temporarily placed on the temporary placement table 204 is heated by the heater to soften the tape 96, thereby making the tape 96 adhere more closely to the base of the ring-shaped reinforcing portion 24 under atmospheric pressure.

[0067] The machining unit 2 in the illustrated embodiment includes a temporary placement table transport unit 232 that transports the temporary placement table 204 in the Y-axis direction. The temporary placement table transport unit 232 includes a Y-axis guide member 234 extending in the Y-axis direction, a Y-axis movable member 236 supported by the Y-axis guide member 234 so as to be movable in the Y-axis direction, and a Y-axis feed unit 238 that moves the Y-axis movable member 236 in the Y-axis direction. The temporary placement table 204 is fixed to an upper portion of the Y-axis movable member 236. The Y-axis feed unit 238 includes a ball screw 240 that is connected to the Y-axis movable member 236 and extends in the Y-axis direction, and a motor 242 that rotates the ball screw 240. The temporary placement table transport unit 232 converts the rotational motion of the motor 242 into linear motion using the ball screw 240 and transmits the linear motion to the Y-axis movable member 236, thereby transporting the temporary placement table 204 together with the Y-axis movable member 236 in the Y-axis direction.

[0068] 1, the reinforcing portion removing means 194 includes a laser processing device 500 that irradiates a laser beam toward the base of a ring-shaped reinforcing portion 24 formed on the outer periphery of the wafer 4 to form a cutting groove, and a separating unit 248 that separates the ring-shaped reinforcing portion 24 from the cutting groove. The laser processing device 500 includes a holding means 502 that holds the wafer 4, a laser beam application means 504 that irradiates a laser beam onto the boundary portion 22 between the device region 18 and the outer periphery excess region 20 of the wafer 4 held by the holding means 502, and a moving means 506 that moves the holding means 502 and the laser beam application means 504 relatively.

[0069] 1, holding means 502 of laser processing apparatus 500 is disposed above temporary placement table 204 so as to be movable in the X-axis direction and the Z-axis direction. Explaining with reference to Fig. 12, holding means 502 includes an X-axis guide member 258 fixed to an appropriate bracket (not shown) and extending in the X-axis direction, an X-axis movable member 260 supported by X-axis guide member 258 so as to be movable in the X-axis direction, and a Z-axis movable member 262 supported by X-axis movable member 260 so as to be movable in the Z-axis direction. A support shaft 264 extending downward is rotatably supported on the underside of the tip of Z-axis movable member 262, and a circular first lift-up table 420 is fixed to the lower end of support shaft 264.

[0070] As shown in FIG. 12(b), the first lifting table 420 has a small-diameter wafer holding portion 422 that is smaller than the outer diameter of the wafer 4 and exposes the ring-shaped reinforcing portion 24, a frame support portion 426 equipped with a permanent magnet 424 that magnetically attaches the frame 64, and a space 428 provided between the wafer holding portion 422 and the frame support portion 426 to diffuse leakage light of the laser beam.

[0071] 12(b), the wafer holder 422 is disposed in the center of the lower surface of the first lift table 420, and the diameter of the wafer holder 422 is slightly smaller than the diameter of the device region 18 (circular recess 23) of the wafer 4. A circular suction chuck 430 made of a porous material is provided at the lower end of the wafer holder 422, and the suction chuck 430 is connected to suction means (not shown).

[0072] The frame support 426 is disposed on the outer periphery of the first lift table 420. A plurality of permanent magnets 424 (four in the illustrated embodiment) are provided at the lower end of the frame support 426 at intervals in the circumferential direction. The magnetic force of the permanent magnets 424 is weaker than the magnetic force of the strong permanent magnets 402 of the temporary placement table 204. In addition, an annular recess recessed upward is formed between the wafer holder 422 and the frame support 426 on the underside of the first lift table 420, and this recess forms a space 428 that diffuses leakage light of the laser beam.

[0073] 12(a), the moving means 506 of the laser processing apparatus 500 includes an X-axis feed means (not shown) for moving the X-axis movable member 260 of the holding means 502 in the X-axis direction, a Z-axis feed means (not shown) for moving the Z-axis movable member 262 of the holding means 502 in the Z-axis direction, and a motor 266 attached to the upper surface of the tip of the Z-axis movable member 262 for rotating the support shaft 264 of the holding means 502 about an axis extending in the Z-axis direction. Each of the X-axis and Z-axis feed means of the moving means 506 may include a ball screw and a motor for rotating the ball screw. When the frame unit U temporarily placed on the temporary placement table 204 is held by the holding means 502 of the laser processing means 500, the moving means 506 raises the holding means 502 and moves it in the X-axis direction to position the frame unit U above the laser beam application means 504.

[0074] 10, laser beam application means 504 of laser processing apparatus 500 includes a housing 508 disposed adjacent to temporary placement table 204 in the X-axis direction. Referring to Fig. 13, housing 508 is fitted with an oscillator 510 that oscillates laser beam LB, a condenser 512 that condenses laser beam LB oscillated by oscillator 510, a beam splitter 516 that is disposed between condenser 512 and oscillator 510 and that splits plasma light P emitted from the area processed by irradiation with laser beam LB and directs it to branch path 514, and plasma light detection means 518 that is disposed in branch path 514 and detects plasma light P. 13, the laser beam application means 504 of the illustrated embodiment includes an attenuator 520 that adjusts the power of the laser beam LB oscillated by the oscillator 510, and a mirror 522 that reflects the laser beam LB, the power of which has been adjusted by the attenuator 520 and which has passed through the beam splitter 516, and directs the reflected laser beam LB to a condenser 512. For convenience of explanation, the condenser 512 is shown in the form of a condensing lens in FIG.

[0075] The oscillator 510 and the attenuator 520 are electrically connected to a control means 524 consisting of a computer, and their operation is controlled by the control means 524. As shown in Fig. 13, a power setting means 526 for selecting the type of material and setting the power of the laser beam LB is electrically connected to the control means 524. The power setting means 526 is provided, for example, on an operation panel (not shown) for operating the processing device 2, and an operator can select the type of material and set the power of the laser beam LB via the power setting means 526 provided on the operation panel.

[0076] For example, if the operator selects silicon as the type of material through the power setting means 526, the power setting means 526 sets 1.0 W as the power for performing appropriate laser processing on silicon, if aluminum is selected the power is set to 2.0 W, and if copper is selected the power is set to 2.5 W. Note that the combination of the type of material and the power of the laser beam LB is determined arbitrarily and is not limited to the combinations described above.

[0077] Then, the control means 524 controls the attenuator 520 to adjust the power of the laser beam LB so that it becomes the power set by the power setting means 526. As described above, the power setting means 526 may be configured to set the power in accordance with the material selected by the operator, but the power setting means 526 may also be configured so that the operator can set any power along with the material.

[0078] Beam splitter 516 may be composed of a dichroic mirror that transmits light having the wavelength (e.g., 355 nm) of laser beam LB emitted by oscillator 510, and reflects light having a wavelength other than that of laser beam LB (e.g., plasma light P) and directs it to branch path 514.

[0079] Plasma light detection means 518 includes a diffraction grating 528 that disperses plasma light P, which is guided to branch path 514 by beam splitter 516, in different directions for each wavelength, and an image sensor 530 that receives plasma light P dispersed in different directions for each wavelength by diffraction grating 528.

[0080] Image sensor 530 has multiple light-receiving elements arranged in a line. Each light-receiving element receives plasma light P dispersed in a different direction for each wavelength, and the wavelength of plasma light P received varies depending on the position of the light-receiving element. Image sensor 530 is electrically connected to control means 524 and outputs a signal indicating the light intensity of plasma light P received by each light-receiving element to control means 524. Note that plasma light detection means 518 does not necessarily have to be configured to detect plasma light P directed to branch path 514 by beam splitter 516. In other words, plasma light detection means 518 does not have to be disposed in branch path 514. For example, plasma light detection means 518 may be disposed in a position where it can directly detect plasma light P emitted from the area processed by irradiation with laser beam LB. In this case, beam splitter 516 may be omitted from laser beam application means 504.

[0081] When a signal is output from image sensor 530 of plasma light detection means 518 to control means 524, control means 524 identifies the material of the area subjected to laser processing by irradiation with laser beam LB based on the plasma light P detected by image sensor 530. For example, as shown in Figures 14(a) and 14(b), if signal S1 is output, which indicates a high light intensity of the 251 nm wavelength component of the detected plasma light P, control means 524 identifies the material as silicon; if signal S2 is output, which indicates a high light intensity of the 395 nm wavelength component, control means 524 identifies the material as aluminum; and if signal S3 is output, which indicates a high light intensity of the 515 nm wavelength component, control means 524 identifies the material as copper. Note that a table showing the relationship between the wavelength of plasma light P and the material of the area subjected to laser processing is pre-stored in control means 524.

[0082] Then, if the type of material identified based on plasma light P detected by plasma light detection means 518 differs from the type of material selected by power setting means 526, control means 524 activates error transmission means 532 (see FIG. 13) to transmit an error. Error transmission means 532 is electrically connected to control means 524, and may be, for example, a monitor that displays an error message, a speaker that emits a warning sound related to the error, or a warning lamp that lights up or flashes in the event of an error.

[0083] Alternatively, instead of issuing an error, when the type of material identified based on plasma light P detected by plasma light detection means 518 differs from the type of material selected by power setting means 526, control means 524 may control attenuator 520 to adjust the power of laser beam LB to an appropriate value according to the material (for example, a value shown in the table of Figure 14(b)).

[0084] Explaining with reference to Fig. 10, the laser processing apparatus 500 includes a suction nozzle 534 that sucks up debris generated when the wafer 4 is irradiated with the laser beam LB, and suction means (not shown) connected to the suction nozzle 534. As shown in Fig. 10, the condenser 512 extends upward from the top surface of the housing 508 at an incline toward the suction nozzle 534, thereby preventing debris generated during irradiation with the laser beam LB from falling onto the condenser 512. In addition, the suction nozzle 534 extends upward from the top surface of the housing 508 at an incline toward the condenser 512.

[0085] In the laser processing apparatus 500, the tape 96 is heated by the heater of the frame holding portion 228 of the temporary placement table 204, and the frame 64 of the frame unit U, with the tape 96 in close contact with the base of the ring-shaped reinforcing portion 24, is held by the permanent magnet 424 of the frame support portion 426 of the first lifting table 420, and the wafer 4 is held by suction with the suction chuck 430 of the wafer holding portion 422. After that, the Z-axis movable member 262 and the X-axis movable member 260 are moved, and the frame unit U held by the first lifting table 420 is raised and moved in the X-axis direction to be positioned above the laser beam application means 504.

[0086] When the frame unit U is held by the first lifting table 420 of the holding means 502, the strong permanent magnet 402 of the frame holding portion 228 of the temporary placement table 204 is positioned in a lowered position to separate the strong permanent magnet 402 from the frame 64, so that the magnetic force acting on the frame 64 placed on the temporary placement table 204 from the permanent magnet 424 of the first lifting table 420 in contact with the frame 64 is stronger than the magnetic force acting on the frame 64 from the strong permanent magnet 402 of the temporary placement table 204.

[0087] 13 and 15, the laser processing apparatus 500 rotates the frame unit U held by the first lift table 420 by the motor 266 of the moving means 506, while irradiating a laser beam LB toward the base of the ring-shaped reinforcing portion 24 formed on the outer periphery of the wafer 4, thereby forming a ring-shaped cutting groove 256 along the base of the reinforcing portion 24 by ablation processing. The laser processing apparatus 500 also uses a suction nozzle 534 to suck in debris generated by the ablation processing.

[0088] Then, when plasma light P is no longer detected by plasma light detection means 518 (when no signal is output from image sensor 530), control means 524 determines that cutting grooves 256 have been formed in wafer 4 (wafer 4 has been completely cut), and stops the irradiation of laser beam LB. Therefore, irradiation of laser beam LB even when wafer 4 has already been cut is prevented.

[0089] Furthermore, the moving means 506 of the laser processing apparatus 500 moves the frame unit U, in which the cutting groove 256 is formed at the base of the reinforcing portion 24, in the X-axis direction and the Z-axis direction to move it to the temporary placement table 204. Note that, since debris adheres to the outer periphery of the wafer 4 due to the irradiation of the laser beam LB, it is preferable to operate only the strong permanent magnet 402 and stop the suction of the annular support portion 226 of the temporary placement table 204 when transferring the frame unit U from the first lift table 420 to the temporary placement table 204. This prevents debris from adhering to the suction holes 229 of the annular support portion 226. Furthermore, from the viewpoint of preventing debris from adhering to the suction holes 229, it is desirable to position the annular support portion 226 in the lowered position.

[0090] 1, the separating unit 248 is disposed at a distance in the Y-axis direction from the holding means 502 within the movable range of the temporary placement table 204 in the Y-axis direction. Explaining with reference to FIGS. 16 and 18, the separating unit 248 includes an ultraviolet ray irradiation unit 270 (see FIG. 16) that irradiates ultraviolet rays onto the tape 96 corresponding to the cutting grooves 256 to reduce the adhesive strength of the tape 96, a second lifting table 272 (see FIG. 16) that exposes the ring-shaped reinforcing portions 24 to the outer periphery, suction-holds the inside of the wafer 4, and supports the frame 64, a separator 274 (see FIG. 16) that acts on the outer periphery of the ring-shaped reinforcing portions 24 to separate the ring-shaped reinforcing portions 24, and a disposal unit 276 (see FIG. 18) that discards the separated ring-shaped reinforcing portions 24.

[0091] 16, separating unit 248 in the illustrated embodiment includes a Z-axis guide member 278 fixed to an appropriate bracket (not shown) and extending in the Z-axis direction, a Z-axis movable member 280 supported by Z-axis guide member 278 so as to be movable in the Z-axis direction, and a Z-axis feed means (not shown) that moves Z-axis movable member 280 in the Z-axis direction. The Z-axis feed means may be configured to include a ball screw connected to Z-axis movable member 280 and extending in the Z-axis direction, and a motor that rotates this ball screw.

[0092] A support piece 282 is supported on the lower surface of the tip of Z-axis movable member 280, and a support shaft 286 is rotatably supported on the lower surface, and the second lift table 272 is connected to this support shaft 286. A motor 284 is attached to the upper surface of the tip of Z-axis movable member 280, which rotates second lift table 272 together with support shaft 286. In the illustrated embodiment, a pair of the ultraviolet ray irradiation units 270 are attached to support piece 282 at an interval in the Y-axis direction.

[0093] The second lift table 272 is circular, and the diameter of the second lift table 272 is slightly smaller than the diameter of the device region 18 (circular recess 23) of the wafer 4. A plurality of suction holes (not shown) are formed in the lower surface of the second lift table 272, and each suction hole is connected to a suction means.

[0094] The separator 274 is attached to the support piece 282. The separator 274 includes a pair of movable pieces 288 that are spaced apart from each other and arranged on the lower surface of the support piece 282 so as to be movable in the longitudinal direction of the support piece 282, and a pair of feeding means 290 that moves the pair of movable pieces 288. Each of the pair of feeding means 290 can be formed from an appropriate actuator such as an air cylinder or an electric cylinder.

[0095] The separator 274 includes a pair of sandwiching rollers 292a, 292b supported by the movable pieces 288 at a vertically spaced interval, and a Z-axis feed means 294 that moves the upper sandwiching roller 292a in the Z-axis direction. The Z-axis feed means 294 may be formed from an appropriate actuator such as an air cylinder or an electric cylinder. Each sandwiching roller 292a, 292b is supported by the movable piece 288 so as to be rotatable about an axis extending in the X-axis direction. A pressure roller 298 is attached to the upper sandwiching roller 292a via a support shaft 296.

[0096] Referring to FIG. 18, the disposal section 276 includes a belt conveyor 300 that transports the separated ring-shaped reinforcing parts 24, and a dust box 302 that stores the ring-shaped reinforcing parts 24 transported by the belt conveyor 300. The belt conveyor 300 is positioned by an appropriate actuator (not shown) at a collection position (position indicated by a solid line in FIG. 18) that extends substantially horizontally, and a standby position (position indicated by a two-dot chain line in FIG. 18) that extends substantially vertically. In FIG. 18, a door 304 with a handle 304a is provided on the side of the dust box 302 that is on the front side in the X-axis direction. A crusher (not shown) that crushes the collected ring-shaped reinforcing parts 24 is attached inside the dust box 302. In the dust box 302, by gripping the handle 304a and opening the door 304, the crushed pieces of the ring-shaped reinforcing part 24 stored in the dust box 302 can be taken out.

[0097] 17 , the separation unit 248 suction-holds the back surface 4b of the wafer 4 of the frame unit U with the second lift-up table 272, sandwiches the frame 64 between the sandwiching rollers 292a and 292b of the separator 274, and then irradiates ultraviolet rays from the pair of ultraviolet irradiation units 270 to reduce the adhesive force of the tape 96 attached to the ring-shaped reinforcement unit 24. The pressure roller 298 presses the ring-shaped reinforcement unit 24 downward. Then, the motor 284 rotates the frame unit U together with the support shaft 286 and the second lift-up table 272 relative to the separator 274, thereby separating the ring-shaped reinforcement unit 24 from the frame unit U. The separated reinforcement unit 24 is transported by the belt conveyor 300 to a dust box 302 for collection. When separating the reinforcing portion 24, the separator 274 may be rotated relative to the frame unit U.

[0098] 1, the ring-free unit carrying-out means 196 is disposed adjacent to the reinforcing portion removing means 194. Explaining with reference to FIGS. 19 and 20, the ring-free unit carrying-out means 196 in the illustrated embodiment includes an inverting mechanism 308 (see FIG. 19) that faces the ring-free unit supported by the second lift table 272 and has a frame holding part 306 that holds the frame 64, moves toward the frame cassette table 200, and inverts the frame holding part 306, a ring-free unit supporting part 310 (see FIG. 20) that supports the ring-free unit that has been inverted by the inverting mechanism 308 so that the front surface 4a of the wafer 4 faces upward, and a pushing part 312 (see FIG. 20) that inserts and accommodates the ring-free unit supported by the ring-free unit supporting part 310 into the frame cassette 198 placed on the frame cassette table 200.

[0099] 19, reversing mechanism 308 includes a Y-axis guide member 314 extending in the Y-axis direction, a Y-axis movable member 316 supported by Y-axis guide member 314 so as to be movable in the Y-axis direction, a Y-axis feed means (not shown) for moving Y-axis movable member 316 in the Y-axis direction, an arm 318 supported by Y-axis movable member 316 so as to be movable in the Z-axis direction, and a Z-axis feed means (not shown) for moving arm 318 in the Z-axis direction. Each of the Y-axis and Z-axis feed means of reversing mechanism 308 may be configured to include a ball screw and a motor for rotating the ball screw.

[0100] The frame holding unit 306 is supported on the arm 318 so as to be capable of being turned upside down, and a motor 320 is attached to turn the frame holding unit 306 upside down. In the illustrated embodiment, the frame holding unit 306 includes a substrate 324 rotatably supported on the arm 318 via a pair of rotation shafts 322, and a plurality of suction pads 326 attached to one side of the substrate 324, with each suction pad 326 connected to suction means (not shown). One of the rotation shafts 322 is connected to the motor 320.

[0101] With the suction pads 326 facing upward, the inversion mechanism 308 sucks and holds the lower surface of the frame 64 of the ring-free unit U' supported by the second lift table 272 with the suction pads 326, and receives the ring-free unit U' from the second lift table 272. The inversion mechanism 308 also inverts the frame holding part 306 with the motor 320 so that the front surface 4a of the wafer 4 faces upward, and then moves the Y-axis movable member 316 to move the ring-free unit U' held by the frame holding part 306 toward the frame cassette table 200.

[0102] 20, the ring-less unit support section 310 of the illustrated embodiment includes a pair of support plates 328 supported via suitable brackets (not shown) so as to be movable in the X-axis direction, and a gap adjustment means (not shown) for adjusting the gap in the X-axis direction between the pair of support plates 328. The gap adjustment means may be constituted by a suitable actuator such as an air cylinder or an electric cylinder.

[0103] A heater (not shown) is attached to the pair of support plates 328 that support the ring-less unit U'. When the gap between the pair of support plates 328 is narrowed, the pair of support plates 328 heats the tape 96 of the ring-less unit U' with the heater, thereby smoothing out any sagging or wrinkles in the tape 96 that have occurred due to the removal of the reinforcing portion 24.

[0104] 20 , pushing unit 312 in the illustrated embodiment includes a Y-axis guide member 330 extending in the Y-axis direction, a Y-axis movable member 332 supported by Y-axis guide member 330 so as to be movable in the Y-axis direction, and a Y-axis feed means (not shown) for moving Y-axis movable member 332 in the Y-axis direction. Y-axis movable member 332 has a base 334 supported by Y-axis guide member 330, a support column 336 extending upward from the top surface of base 334, and a pressing piece 338 attached to the upper end of support column 336. The Y-axis feed means of pushing unit 312 may include a ball screw connected to Y-axis movable member 332 and extending in the Y-axis direction, and a motor for rotating the ball screw.

[0105] 21 , before receiving the ring-free unit U′, the ring-free unit supporting section 310 widens the gap between the pair of support plates 328 using a gap adjusting means, and then receives the ring-free unit U′ held by the suction pad 326. Then, when the ring-free unit supporting section 310 receives the ring-free unit U′, the pushing section 312 moves the Y-axis movable member 332 in the Y-axis direction using the Y-axis feed means, thereby causing the ring-free unit U′ supported by the ring-free unit supporting section 310 to enter the frame cassette 198 placed on the frame cassette table 200 with the pressing piece 338 and accommodate it therein.

[0106] 1 and 21 accommodates a plurality of ring-less units U' spaced apart in the vertical direction with the surfaces 4a of the wafers 4 facing upward. As shown in FIGS. 20 and 21, the frame cassette table 200 includes a mounting section 340 on which the frame cassette 198 is placed, and an elevator section 342 that raises and lowers the mounting section 340 to position it at a desired height. The elevator section 342 may include a ball screw that is connected to the mounting section 340 and extends in the Z-axis direction, and a motor that rotates the ball screw.

[0107] Next, we will explain a processing method in which, using the processing unit 2 as described above, a dicing tape 96 is attached to the back surface 4b of a wafer 4 having a convex ring-shaped reinforcing portion 24 formed on the back surface 4b corresponding to the peripheral excess region 20 to integrate it with the frame 64, and the ring-shaped reinforcing portion 24 is cut and removed from the wafer 4.

[0108] 1 and 3, in the illustrated embodiment, a wafer cassette loading step is first performed in which a wafer cassette 6 containing a plurality of wafers 4 is loaded onto a wafer cassette table 8. The cassette 6 contains a plurality of wafers 4 spaced apart in the vertical direction with their surfaces 4a facing upward.

[0109] 1 and 5, a frame accommodating step is performed in which a plurality of ring-shaped frames 64, each having an opening 64a for accommodating a wafer 4, are accommodated in a frame accommodating means 66. The frame accommodating step may be performed before or after the wafer cassette loading step.

[0110] In the frame storage step, the lift plate 74 of the frame storage means 66 is lowered to a desired position, and then the handle 76a is grasped to open the door 76, and multiple frames 64 are stacked and stored on the upper surface of the lift plate 74. The height of the lift plate 74 is also adjusted appropriately, and the uppermost frame 64 is positioned so that it can be carried out by the frame carrying-out means 68.

[0111] After the wafer cassette placing step and the frame accommodating step are performed, a wafer carrying-out step is performed in which the wafers 4 are carried out from the wafer cassette 6 placed on the wafer cassette table 8 .

[0112] Explaining with reference to Figure 3, in the wafer unloading step, first, the Y-axis feed means 34 of the wafer unloading means 10 is operated to position the Y-axis movable member 32 near the wafer cassette table 8. Next, the transfer arm 42 is driven to position the hand 44, with the air outlet 46 facing upward, on the back surface 4b side (lower side) of the wafer 4 in the wafer cassette 6. When the hand 44 is positioned on the back surface 4b side of the wafer 4, a gap is provided between the back surface 4b of the wafer 4 and the hand 44, and each guide pin 48 is positioned radially outward.

[0113] Next, compressed air is ejected from the air ejection ports 46 of the hand 44 to generate a negative pressure on one side of the hand 44 by the Bernoulli effect, and the hand 44 suction-supports the wafer 4 from the back surface 4b side without contact. Next, each guide pin 48 is moved radially inward, and the horizontal movement of the wafer 4 suction-supported by the hand 44 is restricted by each guide pin 48. Then, the Y-axis movable member 32 and the transfer arm 42 of the wafer unloading means 10 are moved, and the wafer 4 suction-supported by the hand 44 is unloaded from the wafer cassette 6.

[0114] After the wafer carrying-out step is performed, it is preferable to perform a notch detection step in which the position of the notch 26 in the wafer 4 is detected. In the notch detection step, as shown in Fig. 4, the outer periphery of the wafer 4 supported by suction with the hand 44 is positioned between the light-emitting element 52 and the light-receiving element 54 of the notch detection means 50. Next, the wafer 4 is rotated by the drive source via the guide pin 48, thereby detecting the position of the notch 26 in the wafer 4. This makes it possible to adjust the orientation of the wafer 4 to any desired orientation.

[0115] After the notch detection step is performed, a wafer supporting step is performed in which the front surface 4 a side of the wafer 4 carried out by the wafer carrying-out means 10 is supported by the wafer table 12 .

[0116] 3, in the wafer supporting step, first, the hand 44 of the wafer unloading means 10 is turned upside down so that the front surface 4a of the wafer 4 faces downward. Next, the Y-axis movable member 32 and the transfer arm 42 of the wafer unloading means 10 are moved so that the peripheral excess region 20 of the front surface 4a of the wafer 4, which is suction-supported by the hand 44, comes into contact with the annular support portion 56 of the wafer table 12. At this time, because the device region 18 on the front surface 4a of the wafer 4 is located in the recess 62 of the wafer table 12, the device 14 does not come into contact with the wafer table 12, and damage to the device 14 is prevented.

[0117] Next, the suction means of the wafer table 12 is activated to generate suction force in each suction hole 60, thereby suction-holding the peripheral excess region 20 of the front surface 4a of the wafer 4. Next, suction support of the wafer 4 by the hand 44 is released, and the hand 44 is moved away from the wafer table 12. In this manner, the wafer 4 is transferred from the wafer transfer means 10 to the wafer table 12. Because the wafer 4 transferred to the wafer table 12 is held by suction by each suction hole 60, the position of the wafer 4 does not shift.

[0118] After the wafer cassette loading step and the frame accommodating step are performed, a frame carrying-out step of carrying out the frame 64 from the frame accommodating means 66 is performed in parallel with the wafer carrying-out step and wafer supporting step.

[0119] Explaining with reference to Figure 5, in the frame carry-out step, first, the X-axis movable member 84 and Z-axis movable member 86 of the frame carry-out means 68 are moved so that the suction pad 92 of the holding unit 88 comes into contact with the upper surface of the top frame 64 housed in the frame housing means 66. Next, the suction means of the frame carry-out means 68 is activated to generate a suction force in the suction pad 92, thereby suction-holding the top frame 64 with the suction pad 92. Then, the X-axis movable member 84 and Z-axis movable member 86 of the frame carry-out means 68 are moved, and the top frame 64 that has been suction-held by the suction pad 92 of the holding unit 88 is carried out of the frame housing means 66.

[0120] After the frame carrying-out step is performed, a frame supporting step is performed in which the frame 64 carried out by the frame carrying-out means 68 is supported by the frame table 70.

[0121] Continuing the explanation with reference to Figure 5, in the frame supporting step, first, the X-axis movable member 84 and Z-axis movable member 86 of the frame carry-out means 68 are moved so that the frame 64, which is suction-held by the suction pads 92, comes into contact with the upper surface of the frame table 70. At this time, the frame table 70 is positioned in the lowered position (the position indicated by the solid line in Figure 5). Next, the suction force of the suction pads 92 of the frame carry-out means 68 is released, and the frame 64 is placed on the frame table 70. Then, the X-axis movable member 84 and Z-axis movable member 86 of the frame carry-out means 68 are moved so that the holder 88 is separated from above the frame table 70.

[0122] After the frame supporting step is performed, a tape applying step is performed in which tape 96 is applied to the frame 64 .

[0123] Explaining with reference to Figure 6, in the tape application process, first, before moving the frame table 70 from the lowered position (the position shown in Figure 6(a)) to the raised position (the position shown in Figure 6(b)) where the tape 96 can be applied to the frame 64, the tape 96 is pulled out from the roll tape 96R and the tape 96 from which the release paper 116 has been peeled is positioned above the frame table 70. Note that the adhesive side of the tape 96 positioned above the frame table 70 faces downward.

[0124] Next, the frame table 70 is raised to an extent that the pressure roller 132 of the pressure applying unit 110 of the tape applying means 98 can press the tape 96 from above onto the frame 64. Then, the pressure roller 132 is rolled in the Y-axis direction while pressing the adhesive surface of the tape 96 against the frame 64. This allows the tape 96, which has been pulled out from the roll tape 96R by the tape pull-out unit 108, to be pressure-bonded to the frame 64.

[0125] Next, the cutter 144 and pressure roller 146 of the cutting unit 112 of the tape application means 98 are lowered, pressing the cutter 144 against the tape 96 on the frame 64, and the pressure roller 146 presses the frame 64 from above the tape 96. Next, the motor 138 rotates the arm piece 140, causing the cutter 144 and pressure roller 146 to move in a circular motion along the frame 64. This allows the tape 96 that extends beyond the outer periphery of the frame 64 to be cut along the frame 64. In addition, because the pressure roller 146 presses the frame 64 from above the tape 96, displacement of the frame 64 and the tape 96 while cutting the tape 96 is prevented. The used tape 96 with the circular opening 120 formed therein is taken up by the tape take-up unit 106.

[0126] After the tape application process is performed, the frame 64 with the tape 96 applied thereto is transported to the wafer table 12, and the tape-attached frame transport process is performed in which the opening 64a of the frame 64 is positioned on the back surface 4b of the wafer 4 supported on the wafer table 12 and the tape-attached frame 64' is placed on the wafer table 12.

[0127] In the tape-attached frame transport process, first, the frame table 70 is moved from the raised position to the lowered position. Next, the Y-axis movable member 150 and the Z-axis movable member 152 of the tape-attached frame transport means 100 (see FIG. 5) are moved, and each suction pad 158 of the holding part 154 of the tape-attached frame transport means 100 is brought into contact with the upper surface of the tape-attached frame 64' (see FIG. 7) supported on the frame table 70 with the adhesive side of the tape 96 facing downward.

[0128] Next, the suction means of the tape-attached frame transport means 100 is activated to generate suction force in the suction pads 158, thereby suction-holding the upper surface of the tape-attached frame 64' with the suction pads 158. Next, the Y-axis movable member 150 and Z-axis movable member 152 of the tape-attached frame transport means 100 are moved, and the tape-attached frame 64' held by suction with the suction pads 158 is carried out of the frame table 70.

[0129] Next, the tape-attached frame 64' held by suction with the suction pads 158 of the tape-attached frame transport means 100 is transported to the wafer table 12, and as shown in Fig. 7, the opening 64a of the frame 64 is positioned over the back surface 4b of the wafer 4 supported on the wafer table 12, and the tape-attached frame 64' is brought into contact with the frame support portion 58 of the wafer table 12. At this time, the adhesive surface of the tape 96 of the tape-attached frame 64' faces downward, and the back surface 4b of the wafer 4 faces upward, facing the adhesive surface of the tape 96.

[0130] Next, the suction force of the suction pad 158 of the tape-attached frame transport means 100 is released, and the tape-attached frame 64' is placed on the frame support part 58 of the wafer table 12. Then, the Y-axis movable member 150 and the Z-axis movable member 152 of the tape-attached frame transport means 100 are moved, and the holding part 154 is moved away from above the wafer table 12.

[0131] After the tape-attached frame transport step is performed, a tape pressing step is performed in which the tape 96 of the tape-attached frame 64' is pressed onto the back surface 4b of the wafer 4.

[0132] 7 to 9, in the tape pressing step, first, the upper chamber 160 is lowered by the lifting mechanism 164 of the tape pressing means 102, and the lower end of the side wall 172 of the upper chamber 160 is brought into contact with the upper end of the side wall 186 of the lower chamber 162. This closes the upper chamber 160 and the lower chamber 162, and brings the pressure roller 174 into contact with the tape-attached frame 64'. Then, as shown in FIG. 8, the upper end of the ring-shaped reinforcing portion 24 of the wafer 4 is stuck to the adhesive surface of the tape 96 of the tape-attached frame 64'.

[0133] Next, with the atmosphere vent portion 168 of the tape pressing means 102 closed, the vacuum portion 166 is operated to evacuate the interior of the upper chamber 160 and the lower chamber 162. Next, as shown in FIGS. 8 and 9 , the pressure roller 174 of the tape pressing means 102 is rolled in the Y-axis direction to press the tape 96 onto the back surface 4b of the wafer 4. This allows the production of a frame unit U in which the back surface 4b of the wafer 4 and the tape 96 are pressed together. Next, the atmosphere vent portion 168 is opened, and atmospheric pressure causes the tape 96 to adhere tightly to the back surface 4b of the wafer 4 along the base of the ring-shaped reinforcing portion 24. Then, the upper chamber 160 is raised by the lifting mechanism 164. By creating a vacuum inside the upper chamber 160 and the lower chamber 162, the suction force of the wafer 4 by the wafer table 12 is lost. However, when the upper chamber 160 and the lower chamber 162 are closed, the upper end of the ring-shaped reinforcing portion 24 of the wafer 4 adheres to the adhesive surface of the tape 96 of the tape-attached frame 64', so the position of the wafer 4 does not shift during the tape pressing process.

[0134] After the tape pressing step is performed, a frame unit carrying-out step is performed in which the frame unit U in which the tape 96 of the tape-attached frame 64' and the back surface 4b of the wafer 4 are pressure-bonded is carried out from the wafer table 12.

[0135] Referring to Figure 5, in the frame unit carrying-out process, first, the transport section 206 of the frame unit carrying-out means 192 is operated to bring the lower surface of the suction piece 210 of the wafer holding section 202a of the frame unit holding section 202 into contact with the tape 96 on the back surface 4b side of the wafer 4, and also bring the suction pad 214 of the frame holding section 202b into contact with the frame 64.

[0136] Next, suction force is generated between the suction pieces 210 of the wafer holder 202a and the suction pads 214 of the frame holder 202b, and with all or part of the outer periphery of the wafer 4 exposed, the suction pieces 210 of the wafer holder 202a suction-hold the wafer 4 from the back surface 4b side (the tape 96 side), and the suction pads 214 of the frame holder 202b suction-hold the frame 64. Next, suction-holding of the wafer 4 by the wafer table 12 is released. Then, the transport unit 206 is operated to carry out the frame unit U held by the frame unit holder 202 from the wafer table 12.

[0137] After the frame unit carrying-out step is performed, the center of the wafer 4 is aligned with the center of the temporary placement table 204, and the frame unit U is temporarily placed on the temporary placement table 204 in a temporary placement step.

[0138] Explaining with reference to Fig. 10, in the temporary placement step, first, the frame unit U held by the frame unit holding part 202 is positioned above the imaging part 224. Next, the transport part 206 of the frame unit carry-out means 192 is operated, and at least three points of the exposed portion of the outer periphery of the wafer 4 in the frame unit U held by the frame unit holding part 202 are imaged by the imaging part 224. When the imaging part 224 images the wafer 4 from below, the illumination part 400 illuminates the wafer 4 from above. In this way, the coordinates of at least three points on the outer periphery of the wafer 4 are measured. Next, the center coordinates of the wafer 4 are determined based on the coordinates of the three measured points. The wafer 4, which is held by suction by the suction piece 210 of the wafer holder 202a, has all or part of its outer periphery exposed. Therefore, by illuminating the exposed portion of the outer periphery of the wafer 4 from above using the illumination unit 400 and capturing an image of the exposed portion of the outer periphery of the wafer 4 from below using the imaging unit 224, the outline of the wafer 4 can be clearly captured and the center coordinates of the wafer 4 can be precisely determined.

[0139] Next, the transport unit 206 is operated to position the center of the wafer 4 at the center of the annular support portion 226 of the temporary placement table 204, and the peripheral excess region 20 of the front surface 4 a of the wafer 4 is brought into contact with the upper surface of the annular support portion 226 of the temporary placement table 204. At the same time, the lower surface of the frame 64 is brought into contact with the upper surface of the frame support portion 228 of the temporary placement table 204, and the frame 64 is held by the magnetic force of the strong permanent magnets 402. At this time, the strong permanent magnets 402 and the annular support portion 226 are positioned in their raised positions. Next, the suction means of the temporary placement table 204 is operated to generate suction forces in the suction holes 229, thereby suction-holding the peripheral excess region 20 of the front surface 4 a of the wafer 4. Furthermore, at this time, although the front surface 4 a of the wafer 4 faces downward, the device region 18 is located in the recess 230 of the temporary placement table 204, so that the devices 14 do not come into contact with the temporary placement table 204, and damage to the devices 14 is prevented.

[0140] Next, the suction hold of the wafer 4 by the wafer holder 202a is released, and the suction hold of the frame 64 by the frame holder 202b is released, and the frame unit U is transferred from the frame unit carry-out means 192 to the temporary placement table 204. Next, the heater of the frame support part 228 is activated, and the tape 96 of the frame unit U temporarily placed on the temporary placement table 204 is heated by the heater. This softens the tape 96, and the tape 96 is brought into close contact with the base of the ring-shaped reinforcing part 24 of the wafer 4.

[0141] After the temporary placement step is performed, a reinforcing portion removing step is performed in which the ring-shaped reinforcing portion 24 is cut and removed from the wafer 4 of the frame unit U carried out by the frame unit carrying-out means 192.

[0142] Explaining with reference to Figures 1, 10 and 12, in the reinforcing portion removal process, first, the X-axis movable member 260 and the Z-axis movable member 262 of the holding means 502 of the laser processing apparatus 500 are moved, and the lower surface of the permanent magnet 424 of the first lifting table 420 is brought into contact with the upper surface of the frame 64 of the frame unit U temporarily placed on the temporary placement table 204, so that the frame 64 is held by the magnetic force of the permanent magnet 424, and the lower surface of the suction chuck 430 is brought into contact with the back surface 4b side (tape 96 side) of the wafer 4, so that the wafer 4 is held by the suction force of the suction chuck 430.

[0143] Next, the strong permanent magnets 402 of the temporary placement table 204 are positioned in the lowered position, and the attractive force of the annular support portion 226 is released, and then the first lifting table 420, which is attracting and holding the frame unit U, is raised. As described above, the magnetic force of the permanent magnets 424 of the first lifting table 420 is weaker than the magnetic force of the strong permanent magnets 402 of the temporary placement table 204, and when the strong permanent magnets 402 are positioned in the lowered position, the strong permanent magnets 402 are separated from the frame 64, and the magnetic force of the strong permanent magnets 402 acting on the frame 64 is weakened, making it possible to easily detach the frame unit U from the temporary placement table 204.

[0144] Next, the X-axis movable member 260 and the Z-axis movable member 262 of the holding means 502 are operated, and the frame unit U held by the first lift table 420 is positioned above the laser beam application means 504, as shown in Figures 13 and 15. Next, the focal point of the laser beam LB is positioned at the base of the ring-shaped reinforcing portion 24 of the wafer 4 of the frame unit U.

[0145] Next, while the motor 266 of the moving means 506 rotates the first lift table 420 and the frame unit U, the laser beam LB, whose power has been set to an appropriate value by the power setting means 526, is irradiated onto the base of the ring-shaped reinforcing portion 24 of the wafer 4. This allows ablation to be performed on the base of the ring-shaped reinforcing portion 24 of the wafer 4, forming a ring-shaped cut groove 256. Leakage light of the laser beam LB that has passed through the wafer 4 and the tape 96 is diffused in the space 428 between the wafer holder 422 and the frame support portion 426, thereby reducing adverse effects of the leakage light on the devices 14 on the wafer 4. Furthermore, when the laser beam LB is irradiated onto the wafer 4, the suction means of the laser beam application means 504 is activated to generate a suction force in the suction nozzle 534, and debris generated by the ablation is sucked up by the suction nozzle 534. Then, when plasma light P is no longer detected by plasma light detection means 518, control means 524 determines that cutting grooves 256 have been formed in wafer 4, and stops the irradiation of laser beam LB. Therefore, irradiation of laser beam LB even though wafer 4 has already been cut is prevented.

[0146] When the wafer 4 is irradiated with the laser beam LB, the following processing conditions can be set, for example. Laser beam wavelength: 355nm Laser beam power: 1~2.5W Laser beam repetition rate: 100kHz Motor rotation speed: 60 rpm

[0147] When the wafer 4 is being irradiated with the laser beam LB, if the type of material identified by the control means 524 based on the plasma light P detected by the plasma light detection means 518 differs from the type of material selected by the power setting means 526, an error is transmitted from the error transmitting means 532. This allows the operator to correct the power of the laser beam LB to an appropriate value according to the material of the area to be laser processed, via the power setting means 526. Alternatively, the control means 524 may adjust the power of the laser beam LB to an appropriate value.

[0148] An example of a case in which an error is transmitted is when the material of wafer 4 is silicon, and the surface 4a of wafer 4 is coated with a metal film of aluminum or copper, and the operator selects silicon with power setting means 526. Then, when laser beam LB is irradiated onto the metal film on surface 4a of wafer 4, the type of material (aluminum or copper) identified by control means 524 based on plasma light P detected by plasma light detection means 518 differs from the type of material (silicon) selected with power setting means 526, and an error is transmitted.

[0149] After forming the cutting grooves 256 in the wafer 4, the X-axis movable member 260 and the Z-axis movable member 262 of the holding means 502 are moved so that the lower surface of the frame 64 of the frame unit U held by the first lift table 420 comes into contact with the upper surface of the frame support part 228 of the temporary placement table 204, thereby holding the frame 64 by the magnetic force of the strong permanent magnet 402 positioned at the raised position. At this time, in order to prevent debris adhering to the outer periphery of the wafer 4 from adhering to the suction holes 229, it is preferable that no suction force is generated in the suction holes 229 of the annular support part 226 and that the annular support part 226 is positioned at the lowered position.

[0150] Next, the suction force of the suction chuck 430 of the first lifting table 420 is released, and then the first lifting table 420 is raised. As described above, the magnetic force of the permanent magnets 424 of the first lifting table 420 is weaker than the magnetic force of the strong permanent magnets 402 of the temporary placement table 204, so the frame 64 is handed over from the permanent magnets 424 to the strong permanent magnets 402. Then, when the first lifting table 420 is raised, the frame unit U is held by the temporary placement table 204 and separated from the first lifting table 420. In this way, the frame unit U is handed over from the first lifting table 420 to the temporary placement table 204.

[0151] Next, the temporary placement table 204 that has received the frame unit U is positioned below the separation section 248 of the reinforcing part removing means 194 by the temporary placement table transport section 232 (see FIG. 10). At this time, the belt conveyor 300 of the disposal section 276 is positioned at the standby position. Next, the second lifting table 272 of the separation section 248 is lowered so that the lower surface of the second lifting table 272 comes into contact with the tape 96 on the back surface 4b of the wafer 4. Next, a suction force is generated on the lower surface of the second lifting table 272, and the back surface 4b side of the wafer 4 of the frame unit U is suction-held by the second lifting table 272.

[0152] Next, the strong permanent magnets 402 of the temporary placement table 204 are positioned at the lowered position, and then the second lifting table 272, which attracts and holds the wafer 4 of the frame unit U, is lifted. Next, the temporary placement table 204 is moved below the first lifting table 420, and then, as shown in Fig. 17, the pair of feeding means 290 and Z-axis feeding means 294 of the separator 274 are operated to vertically sandwich the frame 64 between the upper and lower sandwiching rollers 292a, 292b. Also, the belt conveyor 300 of the disposal unit 276 is moved from the standby position to the recovery position.

[0153] Next, ultraviolet light is irradiated from the pair of ultraviolet irradiation units 270 to reduce the adhesive force of the tape 96 attached to the ring-shaped reinforcing portion 24, and the ring-shaped reinforcing portion 24 is pressed downward by the pressure roller 298, while the frame unit U, together with the support shaft 286 and the second lifting table 272, is rotated by the motor 284 relative to the separator 274. This allows the ring-shaped reinforcing portion 24 to be separated from the frame unit U. The reinforcing portion 24 that has fallen from the frame unit U is transported to a dust box 302 by the belt conveyor 300 and collected. Note that the separator 274 may be rotated relative to the frame unit U when separating the reinforcing portion 24.

[0154] After the reinforcing portion removing step is performed, a ring-free unit carrying-out step is performed in which the ring-free unit U′ from which the ring-shaped reinforcing portion 24 has been removed is carried out from the reinforcing portion removing means 194 .

[0155] In the ring-free unit carrying-out process, first, the belt conveyor 300 of the disposal section 276 of the reinforcing part removing means 194 is moved from the recovery position to the standby position. Next, the frame holding section 306 of the reversing mechanism 308 (see FIG. 19 ) of the ring-free unit carrying-out means 196 is positioned below the ring-free unit U′ held by suction on the second lift table 272.

[0156] Next, with the suction pad 326 of the frame holding portion 306 facing upward, the arm 318 is raised and the suction pad 326 of the frame holding portion 306 is brought into contact with the underside of the frame 64 of the ring-less unit U', which is supported by the second lift table 272 and has the front surface 4a of the wafer 4 facing downward.

[0157] Next, suction force is generated in the suction pad 326 of the frame holding portion 306, and the frame 64 of the ring-free unit U' is held by suction with the suction pad 326. Next, the suction hold of the ring-free unit U' by the second lift table 272 is released. As a result, the ring-free unit U' is transferred from the second lift table 272 of the reinforcing part removing means 194 to the frame holding portion 306 of the ring-free unit carry-out means 196.

[0158] After the ring-free unit unloading step is performed, a ring-free unit storing step is performed in which the ring-free unit U' unloaded by the ring-free unit unloading means 196 is stored.

[0159] In the ring-free unit accommodating step, first, the inverting mechanism 308 of the ring-free unit carrying-out means 196 is turned upside down, and the ring-free unit U' held by suction on the frame holding part 306 is turned upside down. As a result, the ring-free unit U' is positioned below the frame holding part 306, and the front surface 4a of the wafer 4 faces upward.

[0160] Next, the Y-axis movable member 316 and arm 318 of the reversing mechanism 308 are moved to bring the ring-free unit U' into contact with the upper surfaces of the pair of support plates 328 of the ring-free unit support section 310. At this time, the gap between the pair of support plates 328 is narrowed by the gap adjustment means, and the pair of support plates 328 are in close contact with each other. Next, the suction hold of the ring-free unit U' by the frame holding section 306 is released, and the ring-free unit U' is placed on the pair of support plates 328. Next, the heaters attached to each support plate 328 are activated to heat the tape 96 of the ring-free unit U', thereby smoothing out any sagging or wrinkles in the tape 96 caused by the removal of the reinforcing section 24. Finally, the ring-free unit U' is again suction-held by the frame holding section 306 and raised.

[0161] Next, after widening the gap between the pair of support plates 328 by the gap adjusting means, the ring-free unit U' is placed on the upper surface of the support plate 328. Then, as shown in FIG. 21 , the pressing piece 338 of the pushing portion 312 pushes the ring-free unit U' supported by the ring-free unit supporting portion 310, causing it to enter and be housed in the frame cassette 198 placed on the frame cassette table 200. In this way, in the processing unit 2, the wafer 4 has a convex ring-shaped reinforcing portion 24 formed on the back surface 4b corresponding to the outer peripheral excess region 20, and the dicing tape 96 can be easily attached to the back surface 4b to integrate the wafer 4 with the frame 64, and the ring-shaped reinforcing portion 24 can be easily cut and removed from the wafer 4, resulting in good productivity.

[0162] As described above, in the laser processing device 500 of the processing unit 2, the power of the laser beam LB irradiated onto the wafer 4 can be easily adjusted based on the detection results of the plasma light P emitted from the area processed by irradiation with the laser beam LB. [Explanation of symbols]

[0163] 4: Wafer 4a: Surface of wafer 4b: Backside of wafer 14: Device 16: Planned division line 18: Device area 20: Surplus outer area 23: Recess 24: Reinforcement 500: Laser processing equipment 502: Holding means 504: Laser beam irradiation means 506: Transportation 510: Oscillator 512: Concentrator 514: Fork in the road 516:Beam splitter 518: Plasma light detection means 526: Power setting means LB: Laser beam P: Plasma light

Claims

1. A laser processing apparatus for processing a wafer by irradiating a laser beam onto the wafer, the wafer having a device region on a surface of which a plurality of devices are formed by dividing the device region by planned division lines, and a peripheral excess region surrounding the device region, The wafer processing apparatus comprises: a holding means for holding a wafer; a laser beam application means for applying a laser beam to a boundary portion between a device region and a peripheral excess region of the wafer held by the holding means; and a moving means for relatively moving the holding means and the laser beam application means; the laser beam application means includes an oscillator that oscillates a laser beam, a condenser that condenses the laser beam oscillated by the oscillator, plasma light detection means that detects plasma light emitted from the region that has been processed by irradiating the laser beam, and power setting means that sets the power of the laser beam in accordance with the type of material selected by an operator; A laser processing apparatus in which the front or back surface of a wafer is coated with a metal film, and the power setting means sets the power of the laser beam in accordance with the type of material of the wafer or metal film selected by an operator.

2. A laser processing apparatus for processing a wafer by irradiating a laser beam onto the wafer, the wafer having a device region on a surface of which a plurality of devices are formed by dividing the device region by planned division lines, and a peripheral excess region surrounding the device region, The wafer processing apparatus comprises: a holding means for holding a wafer; a laser beam application means for applying a laser beam to a boundary portion between a device region and a peripheral excess region of the wafer held by the holding means; and a moving means for relatively moving the holding means and the laser beam application means; the laser beam application means includes an oscillator that oscillates a laser beam, a condenser that condenses the laser beam oscillated by the oscillator, plasma light detection means that detects plasma light emitted from the region that has been processed by irradiating the laser beam, and power setting means that sets the power of the laser beam in accordance with the type of material selected by an operator; The laser processing device generates an error when the type of material identified based on the plasma light detected by the plasma light detection means differs from the type of material selected by the operator via the power setting means.

3. a beam splitter disposed between the condenser and the oscillator for splitting plasma light emitted from a region processed by irradiation with the laser beam and directing the split light to a branch path; 3. The laser processing apparatus according to claim 1, wherein said plasma light detecting means is disposed in said branch path.

4. 3. The laser processing apparatus according to claim 2, wherein the front or back surface of the wafer is coated with a metal film, and the power setting means sets the power of the laser beam in accordance with the type of material of the wafer or metal film selected by the operator.

5. 2. The laser processing apparatus according to claim 1, wherein an error is issued when the type of material identified based on the plasma light detected by said plasma light detection means differs from the type of material selected by the operator via said power setting means.

6. 3. A laser processing apparatus according to claim 1, wherein a recess is formed on the back surface of the wafer corresponding to the device region, and a ring-shaped reinforcing portion is formed in a convex shape on the back surface of the wafer corresponding to the peripheral excess region, and the laser beam is irradiated onto the base of the ring-shaped reinforcing portion.

7. 3. The laser processing apparatus according to claim 1, wherein the irradiation of the laser beam is stopped when the plasma light detecting means no longer detects plasma light.

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