Wafer splitting method

Abstract

This prevents the surface irregularities from being transferred to the ground surface of the wafer. [Solution] During the grinding process, the front surface 101 side of the wafer 100 is held by a chuck table 21 of a grinding device 20 via a resin layer 116 and a glass plate 115 that are resistant to deformation due to external forces. Therefore, when the back surface 104 of the wafer 100 is ground by a grinding wheel 261, even if a grinding load is applied from the grinding wheel 261, the resin layer 116 and the glass plate 115 are resistant to deformation, and therefore it is possible to effectively prevent the irregularities (bumps 105) formed on the front surface 101 of the wafer 100 from being transferred to the back surface 104, which is the surface to be ground.

Description

[Technical Field]

[0001] The present invention relates to a method for dividing a wafer. [Background technology]

[0002] When grinding a wafer with an uneven surface, liquid resin is supplied to a film (sheet) held on the top surface of the table, and the uneven surface of the wafer is pressed against this resin, spreading the liquid resin over the entire surface of the wafer and then hardening it. This forms a protective member made of the sheet and resin on the surface of the wafer.

[0003] The wafer is then held by the chuck table of the grinding device via the protective member, the backside of the wafer is ground, and the protective member is peeled off from the ground wafer. In addition, to facilitate peeling of the protective member from the wafer, the technology of Patent Document 1 uses a resin whose adhesive strength decreases when it comes into contact with warm water, and the protective member is brought into contact with warm water when peeling off from the wafer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-224659 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the conventional configuration, the sheet that constitutes the protective member together with the resin is easily compressed and deformed (easily dented). As a result, during the grinding process, the sheet receives a grinding load from the grinding wheel and is compressed and deformed in accordance with the unevenness of the wafer's front surface, which can transfer the unevenness to the back surface of the wafer (the surface to be ground).

[0006] Therefore, an object of the present invention is to suppress the transfer of the surface irregularities to the surface to be ground when grinding a wafer having surface irregularities. [Means for solving the problem]

[0007] The wafer dividing method of the present invention (the present dividing method) is a wafer dividing method for dividing a wafer along the streets, the wafer having an uneven surface and devices formed in areas defined by the streets, and includes the steps of: interposing a liquid resin containing a light absorber or a photopolymerization initiator between the entire surface of the wafer and a glass plate for supporting the wafer; applying an external stimulus to harden the liquid resin to form a resin layer; and bonding the glass plate to the surface of the wafer with this resin layer; holding the glass plate on a chuck table of a grinding device; and grinding the back surface of the wafer with a grinding wheel; The process includes a dicing tape application step of applying a dicing tape to the back surface of the wafer, a laser processing step of irradiating a laser beam onto the resin layer from the glass plate side to vaporize a portion of the resin layer, thereby enabling the glass plate to be separated from the resin layer, a glass plate peeling step of peeling the glass plate from the resin layer, a dividing step of dividing the wafer together with the resin layer along the streets using a cutting blade or a laser beam having a wavelength absorbable by the resin layer and the wafer, and a resin peeling step of bringing the resin layer into contact with warm water after the dividing step to peel the resin layer from the front surface of the wafer. [Effects of the Invention]

[0008] In this dividing method, the front side of the wafer is held by the chuck table of the grinding machine via a resin layer and a glass plate that are resistant to deformation by external forces during the grinding process. Therefore, even if a grinding load is applied from the grinding wheel when the back side of the wafer is ground with the grinding wheel, the resin layer and the glass plate are resistant to deformation, and therefore it is possible to effectively prevent the irregularities formed on the front side of the wafer from being transferred to the back side, which is the surface to be ground. [Brief explanation of the drawings]

[0009] [Figure 1] This is a perspective view showing the wafer's structure. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] This is a cross-sectional view showing the dicing tape application process. [Figure 6] This is a cross-sectional view showing the laser processing process. [Figure 7] This is a cross-sectional view showing the glass plate peeling process. [Figure 8] This is a cross-sectional view showing the holding process and the splitting process. [Figure 9] FIG. 10 is a cross-sectional view showing a resin peeling step. [Figure 10] This is a cross-sectional view showing another resin peeling process. DETAILED DESCRIPTION OF THE INVENTION

[0010] As shown in Figure 1, the wafer 100, which is the object to be divided in the wafer division method according to this embodiment, is, for example, a disc-shaped semiconductor wafer. A grid-like street 102 is formed on one side of the wafer 100, which is the surface 101. Multiple devices 103 are formed in the regions demarcated by the street 102. In addition, the surface 101 has a pattern as an uneven surface, or bumps 105 as an uneven surface, as shown in Figure 2.

[0011] The wafer division method according to this embodiment is a method of dividing a wafer 100 having irregularities (bumps 105) on its surface 101 along a street 102. To this end, the wafer splitting method according to this embodiment involves performing a bonding step, a grinding step, a dicing tape bonding step, a laser processing step, a glass plate peeling step, a holding step, a splitting step, and a resin peeling step on the wafer 100.

[0012] [Application process] In this embodiment, a bonding process is first performed. In this process, a liquid resin containing a light absorber or a photopolymerization initiator is interposed between the entire surface 101 of the wafer 100 and a glass plate for supporting the wafer 100, and an external stimulus is applied to harden the liquid resin to form a resin layer, which bonds the glass plate to the surface 101 of the wafer 100.

[0013] 2, an operator or a transport device (not shown) transports the wafer 100 to the holding surface 12 of the wafer holding unit 11 of the protective member forming apparatus 10. Thereafter, the control unit 9 of the protective member forming apparatus 10 connects the holding surface 12 to a suction source (not shown), thereby suction-holding the back surface 104 of the wafer 100 by the holding surface 12.

[0014] Furthermore, an operator or a conveying device (not shown) places a circular glass plate 115 having approximately the same diameter as the wafer 100 on the holding surface 18 of the stage 17 of the protective member forming device 10, and the control unit 9 holds the glass plate 115 by the holding surface 18.

[0015] At this time, the position of the glass plate 115 is adjusted so that the center of the glass plate 115 and the center of the holding surface 18 of the stage 17 approximately coincide with each other. As a result, the center of the wafer 100 held by the wafer holder 11 coincides with the center of the glass plate 115.

[0016] Next, the control unit 9 of the protective member forming device 10 drips a predetermined amount of liquid resin 19 onto the glass plate 115 held by suction using a liquid resin supply nozzle (not shown). In this embodiment, an ultraviolet-curable resin containing a photopolymerization initiator is used as the liquid resin 19. Therefore, the liquid resin 19 is cured by irradiation with ultraviolet rays to become a resin (resin layer). The cured resin layer 116 (see FIG. 3) is a hydrophilic resin, and is configured to lose its adhesive strength (its adhesive strength is reduced) when it comes into contact with warm water.

[0017] The control unit 9 lowers the wafer holding unit 11, which holds the wafer 100, using the lifting mechanism 15 of the protective member forming apparatus 10. As a result, the surface 101 of the wafer 100 comes into contact with the liquid resin 19 supplied to the glass plate 115. Consequently, the liquid resin 19 is pressed by the wafer 100 and the glass plate 115 and spread out radially outward of the wafer 100 to a predetermined thickness, as shown in Figure 3. This interposes the liquid resin 19 between the entire surface 101 of the wafer 100 and the glass plate 115 supporting the wafer 100.

[0018] Subsequently, the control unit 9 applies (irradiates) ultraviolet light as an external stimulus to the liquid resin 19, which has been expanded to a predetermined thickness, from the ultraviolet irradiation unit 16 provided in the stage 17. As a result, the liquid resin 19 hardens, and a resin layer 116 containing a photopolymerization initiator with approximately the same diameter as the wafer 100 is formed on the surface 101 of the wafer 100. Then, the glass plate 115 is attached to the surface 101 of the wafer 100 by this resin layer 116. In this way, a protective member consisting of the glass plate 115 and the resin layer 116 is formed on the surface 101 of the wafer 100. In this embodiment, the protective member forming apparatus 10 formed the protective member with the wafer 100 on top and the glass plate 115 on the bottom. However, it may also be configured to form the protective member with the wafer 100 on the bottom and the glass plate 115 on top.

[0019] [Grinding process] After the bonding process, a grinding process is carried out. In this process, the glass plate 115 is held by the chuck table of the grinding device, and the back surface 104 of the wafer 100 is ground with a grinding wheel.

[0020] Specifically, as shown in Figure 4, an operator or a transport device (not shown) places the wafer 100 on the chuck table 21 of the grinding device 20 with its back surface 104 facing upward. Then, the control unit 29 of the grinding device 20 connects the holding surface 22 to a suction source (not shown), thereby using the holding surface 22 to suction and hold the glass plate 115 attached to the wafer 100. As a result, the wafer 100 is suction-held to the holding surface 22 via the glass plate 115 and the resin layer 116.

[0021] Subsequently, the grinding apparatus 20 positions a grinding mechanism 23 above the chuck table 21 for grinding the back surface 104 of the wafer 100. The grinding mechanism 23 comprises a spindle 24 extending perpendicular to the holding surface 22, a mount 25 attached to the tip of the spindle 24, and a grinding wheel 26 having a grinding wheel 261 held by the mount 25.

[0022] In the grinding process, the control unit 29 rotates the spindle 24 by a motor (not shown) as shown by arrow 301, thereby rotating the mount 25 attached to the lower end of the spindle 24 and the grinding wheel 26. The control unit 29 also rotates the chuck table 21 holding the wafer 100 by a rotation mechanism 28 as shown by arrow 302, for example.

[0023] Then, the control unit 29 lowers the grinding mechanism 23 toward the wafer 100 held on the holding surface 22 using the lifting mechanism 27. As a result, the grinding wheel 261 of the rotating grinding wheel 26 comes into contact with the back surface 104 of the rotating wafer 100 and grinds this back surface 104. In this way, the wafer 100 is ground to a predetermined thickness.

[0024] [Dicing tape application process] After the grinding step, a dicing tape application step is performed in which a dicing tape is applied to the back surface 104 of the wafer 100.

[0025] Specifically, in this step, a work set 110 is created as shown in Fig. 5. This work set 110 includes a wafer 100, an annular ring frame 111, and a dicing tape 113.

[0026] The ring frame 111 has an opening 112 capable of accommodating the wafer 100. In the dicing tape application process, an operator or a mounting device (not shown) applies a sheet-like dicing tape 113 to one surface of the ring frame 111 and the back surface 104 of the wafer 100. As a result, the wafer 100 is mounted on the ring frame 111 by the dicing tape 113, and a work set 110 is formed in which the wafer 100 and the dicing tape 113 are integrated.

[0027] [Laser processing process] After the dicing tape application step, a laser processing step is carried out. In this step, a laser beam is irradiated onto the resin layer 116 from the glass plate 115 side to vaporize a part of the resin layer 106 (the part of the resin layer 116 that is in contact with the glass plate 115), thereby making it possible to separate the glass plate 115 from the resin layer 116.

[0028] 6, an operator or a carrier device (not shown) places the work set 110 on the holding surface 42 of the chuck table 41 of the laser irradiation device 40 so that the glass plate 115 attached to the surface 101 of the wafer 100 faces upward. Thereafter, the control unit 47 of the laser irradiation device 40 connects the holding surface 42 to a suction source (not shown), whereby the wafer 100 of the work set 110 is suction-held to the holding surface 42 via the dicing tape 113.

[0029] Thereafter, the laser irradiation device 40 places a laser oscillator 45 above the chuck table 41. The laser oscillator 45 is configured to irradiate the wafer 100 from the glass plate 115 side with a laser beam L having a wavelength absorbable by the resin layer 116 containing a photopolymerization initiator (a wavelength that is easily absorbed by this resin layer 116).

[0030] In the laser irradiation device 40, the chuck table 41 and the laser oscillator 45 are provided so as to be relatively movable in the horizontal direction. In this embodiment, the chuck table 41 can be moved horizontally in the X-axis direction by a table moving mechanism 43, and the laser oscillator 45 can be moved horizontally in the Y-axis direction by a laser moving mechanism 44.

[0031] In the laser processing step, the control unit 47 of the laser irradiation device 40 causes the table moving mechanism 43 and the laser moving mechanism 44 to move the chuck table 41 and the laser oscillator 45 in the horizontal direction while irradiating the laser beam L from the laser oscillator 45. In this way, the control unit 47 irradiates the entire surface of the resin layer 116 with the laser beam L through the glass plate 115. As a result, a part of the resin layer 116 containing the photopolymerization initiator, i.e., the part of the resin layer 116 that is in contact with the glass plate 115, absorbs the laser beam L and is vaporized, allowing the glass plate 115 to be separated from the resin layer 116.

[0032] [Glass plate peeling process] After the laser processing step, a glass plate peeling step is performed. In this step, the glass plate 115 is peeled off from the resin layer 116. Specifically, as shown in FIG. 7, the control unit 47 of the laser irradiation device 40 uses a peeling mechanism (not shown) to peel off and remove the glass plate 115 from the resin layer 116 formed on the front surface 101 of the wafer 100. Alternatively, the glass plate 115 may be peeled off from the resin layer 116 by an operator.

[0033] [Holding process] After the glass plate peeling step, a holding step is performed. In this step, the wafer 100 is held via a dicing tape 113 on a chuck table 51 of a dividing device 50 that divides the wafer 100 using a cutting blade 55, as shown in FIG.

[0034] Specifically, as shown in Figure 8, an operator or a transport device (not shown) places the workset 110 on the holding surface 52 of the chuck table 51 of the splitting device 50 so that the surface 101 of the wafer 100 faces upward. Then, the control unit 57 of the splitting device 50 connects the holding surface 52 to a suction source (not shown), thereby causing the wafer 100 of the workset 110 to be held in place by suction to the holding surface 52 via the dicing tape 113.

[0035] [Dividing process] After the holding step, a dividing step is performed in which the wafer 100 together with the resin layer 116 is divided along the streets 102 (see FIG. 1) by a cutting blade 55.

[0036] Specifically, as shown in Figure 8, after the wafer 100 is held on the holding surface 52 of the chuck table 51 of the splitting device 50, the control unit 57 positions the cutting blade 55 above the chuck table 51. The chuck table 51 and the cutting blade 55 are provided to be able to move relative to each other in the horizontal direction. In this embodiment, the chuck table 51 is able to move horizontally in the X-axis direction and rotate horizontally by the table movement mechanism 53. In addition, the cutting blade 55 is able to move horizontally in the Y-axis direction and move up and down in the Z-axis direction by the blade movement mechanism 54.

[0037] The control unit 57 then uses the camera 58 to confirm the position of the street 102 on the wafer 100 via the transparent resin layer 116, and adjusts the positions of the cutting blade 55 and the chuck table 51 using the table moving mechanism 53 and the blade moving mechanism 54, thereby positioning the starting position of one street 102 on the wafer 100 held by the chuck table 51 directly below the cutting blade 55.

[0038] Next, the control unit 57 rotates the cutting blade 55 using the rotation mechanism 56, and also controls the blade movement mechanism 54 to lower the rotating cutting blade 55 to a depth at which the resin layer 116 and the wafer 100 are cut. Then, the control unit 57 causes the table movement mechanism 53 to process and feed the wafer 100 in the X-axis direction, thereby moving the wafer 100 along the street 102 relative to the cutting blade 55. As a result, the wafer 100 and the resin layer 116 are divided (cut) along one street 102, and a division groove 118 is formed.

[0039] Thereafter, the control unit 57 controls the table moving mechanism 53 and the blade moving mechanism 54 to cause the cutting blade 55 to divide the wafer 100 and the resin layer 116 along the other streets 102. In this manner, the control unit 57 divides the wafer 100 and the resin layer 116 along all the streets 102 to form dividing grooves 118. As a result, the wafer 100 is divided into a plurality of chips 120, each including one device 103 (see FIG. 1).

[0040] The dividing device 50 may be configured to divide the wafer 100 together with the resin layer 116 along the streets 102 using a laser beam. In this case, the dividing device 50 has a laser beam application mechanism that applies a laser beam along the streets 102, instead of the cutting blade 55. This laser beam has a wavelength that is absorbed by the resin layer 116 and the wafer 100 (a wavelength that is easily absorbed by the resin layer 116 and the wafer 100). Therefore, the dividing step is a step of dividing the wafer 100 together with the resin layer 116 along the streets 102 by the cutting blade 55 or the laser beam.

[0041] [Resin removal process] After the splitting process, a resin peeling process is carried out. In this process, the resin layer 116 is peeled off from the surface 101 of the wafer 100 by bringing the resin layer 116 into contact with hot water.

[0042] 9, an operator or a transfer device (not shown) places the work set 110 on the holding surface 62 of the chuck table 61 of the cleaning device 60 so that the front surface 101 of the wafer 100 faces upward. Thereafter, the control unit 69 of the cleaning device 60 connects the holding surface 62 to a suction source (not shown), whereby the wafer 100 of the work set 110 is suction-held to the holding surface 62 via the dicing tape 113.

[0043] Next, the control unit 69 places the hot water supply mechanism 63 above the chuck table 61. The hot water supply mechanism 63 has a hot water nozzle 64 that sprays hot water W toward the wafer 100 held on the chuck table 61, and a horizontal movement mechanism 65 that moves the hot water nozzle 64 along the horizontal direction (linear movement or rotational movement).

[0044] In the resin peeling step, the control unit 69 of the cleaning device 60 controls the horizontal movement mechanism 65 to position the hot water nozzle 64 above the center of the wafer 100 held on the chuck table 61. Thereafter, the control unit 69 sprays hot water W from the hot water nozzle 64 toward the center of the front surface 101 of the wafer 100. The temperature of the hot water W is a temperature at which the adhesive strength of the resin layer 116 made of a hydrophilic resin decreases, and is, for example, 40°C or higher, and preferably 60°C or higher.

[0045] Furthermore, the control unit 69 causes the rotation mechanism 66 to rotate the chuck table 61 holding the wafer 100. As a result, the hot water W sprayed onto the center of the front surface 101 of the wafer 100 spreads over the entire surface 101 due to centrifugal force and enters all of the division grooves 118.

[0046] As a result, the resin layer 116 formed on the front surface 101 of the wafer 100 comes into contact with the warm water, the adhesive strength of the resin layer 116 decreases, the resin layer 116 floats up from the front surface 101, and is blown off from the front surface 101 by the centrifugal force caused by the rotation of the chuck table 61. In this way, the resin layer 116 is peeled off from the front surface 101 of the wafer 100.

[0047] 4, in the wafer dividing method according to this embodiment, the front surface 101 side of the wafer 100 is held by the chuck table 21 of the grinding device 20 via the resin layer 116, which is resistant to deformation due to external forces and harder than the adhesive layer of the protective tape, and the glass plate 115, which is harder than the base material of the protective tape, during the grinding step. Therefore, when the back surface 104 of the wafer 100 is ground by the grinding wheel 261, even if a grinding load is applied from the grinding wheel 261, the resin layer 116 and the glass plate 115 are resistant to deformation, and therefore it is possible to effectively prevent the unevenness (bumps 105) formed on the front surface 101 of the wafer 100 from being transferred to the back surface 104, which is the surface to be ground.

[0048] 8, in the dividing step, the wafer 100 is divided (cut) together with the resin layer 116 by the cutting blade 55. Therefore, the surface 101 of the wafer 100 can be suppressed (protected) by the resin layer 116 during dividing, and thus chipping can be suppressed.

[0049] Furthermore, even when an insulating film and / or a metal film is formed on the surface 101 of the wafer 100, the surface 101 of the wafer 100 is held down by the resin layer 116, so peeling of these films can be suppressed.

[0050] 6 and 7, in the laser processing step and the glass plate peeling step, the resin layer 116 is irradiated with a laser beam L from the glass plate 115 side of the wafer 100 to vaporize a part of the resin layer 116, thereby peeling and removing the glass plate 115 from the resin layer 116. Therefore, damage to the glass plate 115 can be suppressed when peeling the glass plate 115, and the glass plate 115 can be reused.

[0051] In this embodiment, the laser processing step, glass plate peeling step, dividing step, and resin peeling step are performed using a laser irradiation device 40 (see FIG. 7), a dividing device 50 (see FIG. 8), and a cleaning device 60 (see FIG. 9), respectively. In this regard, these steps may be performed by one or two devices each including two or more of a laser oscillator 45 (see FIG. 7), a cutting blade 55 (see FIG. 8), and a hot water supply mechanism 63 (see FIG. 9).

[0052] For example, the dividing apparatus 50 may further include a hot water supply mechanism 63, so that the dividing step and the resin peeling step are performed in the dividing apparatus 50. Furthermore, the dividing apparatus 50 may further include a laser oscillator 45, so that the laser processing step, the glass plate peeling step, and the dividing step are performed in the dividing apparatus 50. Furthermore, the dividing apparatus 50 may further include a laser oscillator 45 and a hot water supply mechanism 63, so that the laser processing step, the glass plate peeling step, the dividing step, and the resin peeling step are performed in the dividing apparatus 50.

[0053] The cleaning device used in the resin peeling step may be a cleaning device 70 as shown in Fig. 10. The cleaning device 70 includes a chuck table 71 that holds the wafer 100 of the work set 110, a plurality of (for example, four) lifting cylinders 73 that hold and raise and lower the ring frame 111 of the work set 110, a water tank 75 that houses the chuck table 71 and the lifting cylinders 73, a hot water nozzle 74 that supplies hot water W into the water tank 75, and a control unit 79.

[0054] In the resin peeling process using this cleaning device 70, an operator or a transport device (not shown) places the wafer 100 of the workset 110 onto the holding surface 72 of the chuck table 71 via the dicing tape 113 so that its surface 101 faces upward, and places the ring frame 111 onto the table 731 of the lifting cylinder 73. Subsequently, the control unit 79 connects the holding surface 72 and the table 731 of the lifting cylinder 73 to a suction source (not shown), thereby holding the wafer 100 and ring frame 111 of the workset 110 with the chuck table 71 and the lifting cylinder 73.

[0055] Thereafter, the control unit 79 supplies hot water W from the hot water nozzle 74 to the water tank 75. As a result, the wafer 100 held on the chuck table 71 is submerged in the hot water W in the water tank 75. The control unit 79 also rotates the chuck table 71 and the lifting cylinder 73 using the rotation mechanism 76.

[0056] As a result, the resin layer 116 formed on the surface 101 of the wafer 100 comes into contact with the hot water, reducing the adhesive strength of the resin layer 116, causing the resin layer 116 to lift off the surface 101, and then being blown off the surface 101 by the centrifugal force caused by the rotation of the chuck table 71. In this way, the resin layer 116 is peeled off the surface 101 of the wafer 100.

[0057] In the resin peeling process, as shown in Patent Document 1, the work set 110 may be held with the surface 101 of the wafer 100 facing downwards, and the work set 110 may be submerged in a water tank containing hot water, thereby bringing the resin layer 116 into contact with the hot water and peeling the resin layer 116 from the surface 101 of the wafer 100.

[0058] Furthermore, in this embodiment, the liquid resin 19 is an ultraviolet-curable resin containing a photopolymerization initiator, and the resin layer 116 contains a photopolymerization initiator. In this regard, the liquid resin 19 may be an ultraviolet-curable resin containing a photopolymerization initiator and a light absorber. In this case, since the resin layer 116 contains a photopolymerization initiator and a light absorber, the absorption rate of the laser beam L (see Figure 6) in the resin layer 116 can be increased.

[0059] Furthermore, the liquid resin 19 may be a thermosetting resin containing a light absorber. In this case, a resin layer 116 containing the light absorber is formed, and the laser beam L can be absorbed well by the resin layer 116. In this case, during the bonding process, the liquid resin 19 is cured by applying heat as an external stimulus to the liquid resin 19 which has been expanded to a predetermined thickness, thereby forming a resin layer 116 containing a light absorber with approximately the same diameter as the wafer 100 on the surface 101 of the wafer 100. Then, the glass plate 115 is bonded to the surface 101 of the wafer 100 by this resin layer 116. [Explanation of symbols]

[0060] 9: control unit, 10: protective member forming device, 11: wafer holding unit, 12: holding surface, 15: lifting mechanism, 16: ultraviolet irradiation unit, 17: stage, 18: holding surface, 19: liquid resin, 20: Grinding device, 21: Chuck table, 22: Holding surface, 23: Grinding mechanism, 24: Spindle, 25: Mount, 26: Grinding wheel, 27: Lifting mechanism, 28: Rotation mechanism, 29: Control unit, 40: Laser irradiation device, 41: Chuck table, 42: Holding surface, 43: Table movement mechanism, 44: Laser movement mechanism, 45: Laser oscillator, 47: Control unit, 50: dividing device, 51: chuck table, 52: holding surface, 53: table moving mechanism, 54: blade moving mechanism, 55: cutting blade, 56: rotation mechanism, 57: control unit, 58: Camera, 60: Washing device, 61: Chuck table, 62: Holding surface, 63: Hot water supply mechanism, 64: Hot water nozzle, 65: Horizontal movement mechanism, 66: Rotation mechanism, 69: Control unit, 70: Washing device, 71: Chuck table, 72: Holding surface, 73: Lifting cylinder, 74: Hot water nozzle, 75: Water tank, 76: Rotating mechanism, 79: Control unit, 100: wafer, 101: surface, 102: street, 103: device 104: Back surface, 105: Bump, 106: Resin layer, 110: Workset, 111: Ring frame, 112: Opening, 113: Dicing tape, 115: Glass plate, 116: Resin layer, 118: Divided groove, 120: Chip, 261: Grinding wheel, 731: Table, L: Laser beam, W: Hot water

Claims

[Claim 1] A wafer dividing method for dividing a wafer having an uneven surface and devices formed in areas defined by streets along the streets, the method comprising: a bonding step in which a liquid resin containing a light absorber or a photopolymerization initiator is interposed between the entire surface of the wafer and a glass plate for supporting the wafer, and an external stimulus is applied to harden the liquid resin to form a resin layer, and the glass plate is bonded to the surface of the wafer by this resin layer; a grinding step in which the glass plate is held by a chuck table of a grinding device and the back surface of the wafer is ground with a grinding wheel; a dicing tape application step of applying a dicing tape to the back surface of the wafer; a laser processing step of irradiating the resin layer from the glass plate side with a laser beam to vaporize a part of the resin layer, thereby making the glass plate separable from the resin layer; a glass plate peeling step of peeling the glass plate from the resin layer; a dividing step of dividing the wafer together with the resin layer along the streets by a cutting blade or a laser beam having a wavelength absorbed by the resin layer and the wafer; and a resin peeling step of peeling the resin layer from the surface of the wafer by bringing the resin layer into contact with hot water after the dividing step. Wafer division method.

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