Method for forming protective member

Abstract

To provide a method for forming a protective member, which allows a protective member to reliably peel off from a sliced wafer in a short time without leaving the protective member on a sliced wafer.SOLUTION: A method for forming a protective member P according to the present invention includes: a liquid resin supplying step of supplying a predetermined amount of liquid resin r to a center of an upper surface side of an extension table 12; a spreading step of relatively moving a sliced wafer WS held on a holding table 20 in a direction approaching the extension table 12, and spreading, by the sliced wafer WS, the liquid resin r from a center of the sliced wafer WS radially outward up to a front of an outer periphery; and a curing step of applying an external stimulus to the liquid resin r to cure the liquid resin r after separating the holding table 20 from the sliced wafer WS. In the spreading step, when a chamfered portion R is formed on the outer periphery of the sliced wafer WS, the liquid resin r is spread over the entire surface of one side up to the front of the chamfered portion R.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a method for forming a protective member made of a liquid resin on one surface of a sliced ​​wafer sliced ​​from an ingot when the sliced ​​wafer is ground. [Background technology]

[0002] For example, wafers used in the manufacture of semiconductor devices such as ICs and LSIs used in electronic devices are obtained by flattening both sides of as-sliced ​​wafers (hereinafter simply referred to as "sliced ​​wafers") cut by a cutting device such as a blade saw or wire saw from a single crystal ingot of silicon or the like manufactured by a single crystal pulling method such as the Czochralski method, using a grinding device or polishing device. Devices such as ICs and LSIs are then formed on the front surface of the wafer thus flattened on both sides, the back surface of the wafer on which these devices are formed is ground to thin the wafer to a predetermined thickness, and the thinned wafer is cut by a cutting device such as a dicing saw to divide it into individual devices.

[0003] Incidentally, sliced ​​wafers cut from an ingot have warping due to differences in the magnitude of processing strain that occurs on both sides during cutting processing using a cutting device such as a blade saw or a wire saw, and undulations that occur on the surface layers of both sides. For this reason, a processing method has been proposed in which a protective member such as an ultraviolet curing resin is formed on one side of the sliced ​​wafer to flatten the surface, the other side of the sliced ​​wafer is ground while the flat one side of the protective member is held by the holding surface of a chuck table to flatten the other side, the protective member is peeled off and stripped from the slide wafer, and one side of the sliced ​​wafer is ground while the other flat side is held by the holding surface of a chuck table to make it flat (see, for example, Patent Documents 1 and 2).

[0004] However, when the other surface of the sliced ​​wafer on which the protective member is not formed is flattened by grinding, a part of the protective member may remain on the outer periphery of the sliced ​​wafer when the protective member is peeled off from one surface of the sliced ​​wafer.If a part of the protective member remains on the outer periphery of the sliced ​​wafer in this manner, a problem occurs in that the sliced ​​wafer cannot be ground to a uniform thickness over its entire surface when one surface of the sliced ​​wafer (the surface from which the protective member has been peeled off) is ground while the other surface of the sliced ​​wafer flattened by grinding is held by the holding surface of a chuck table.

[0005] Therefore, Patent Document 3 proposes a peeling device that reliably peels a protective member from a sliced ​​wafer without leaving any protective member on the outer periphery of the sliced ​​wafer. This peeling device includes an outer periphery peeling means that peels the protective member from the wafer leaving a part of the outer periphery of the protective member, and an entire peeling means that peels the entire protective member from the wafer, and the entire peeling means includes a gripping part that grips a part of the outer periphery of the protective member that remains not peeled by the outer periphery peeling means, and a roller part that presses the center of the lower surface of the protective member. In this entire peeling means, the roller part presses the center part of the protective member against the wafer while peeling the entire protective member from the wafer.

[0006] Moreover, Patent Document 4 proposes a wafer cleaning device that removes protective material remaining on the outer periphery of the wafer by cleaning with an upper roll sponge and a lower roll sponge. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2006-269761 A [Patent Document 2] JP 2009-272557 A [Patent Document 3] JP 2019-009200 A [Patent Document 4] JP 2020-202322 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, the peeling device proposed in Patent Document 3 and the cleaning device proposed in Patent Document 4 have a problem in that it takes time to peel off the protective member.

[0009] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a method for forming a protective member that can reliably and quickly peel off the protective member from the sliced ​​wafer without leaving any protective member on the sliced ​​wafer. [Means for solving the problem]

[0010] The present invention for solving the above-mentioned problems provides a method for forming a protective member, which forms a protective member by spreading liquid resin over the entire surface of one side of a sliced ​​wafer sliced ​​from an ingot and hardening the resin by applying an external stimulus when manufacturing the sliced ​​wafer by grinding both sides of the sliced ​​wafer, the method comprising the steps of: supplying a predetermined amount of liquid resin to the center of the upper surface side of an extension table which spreads the liquid resin; and moving the sliced ​​wafer held on a holding table arranged opposite to the extension table relatively in a direction approaching the extension table, so that the sliced ​​wafer is spread with the liquid resin by the sliced ​​wafer. The method comprises a spreading process for spreading the liquid resin from the center of the wafer radially outward to just before the outer periphery, and a hardening process for applying an external stimulus to the liquid resin after separating the holding table from the sliced ​​wafer to harden the liquid resin, wherein in the spreading process, if a chamfered portion is formed on the outer periphery of the sliced ​​wafer, the liquid resin is spread over the entire surface of one side up to just before the chamfered portion, and if no chamfered portion is formed on the outer periphery of the sliced ​​wafer, the liquid resin is spread over the entire surface of one side up to just before the outer periphery side of the sliced ​​wafer. Effect of the Invention

[0011] According to the present invention, in the spreading step, the liquid resin spread on one surface of the sliced ​​wafer is prevented from reaching the chamfered portion formed on the outer periphery of the sliced ​​wafer, so that the liquid resin is spread over the entire radially inner portion of the chamfered portion on one surface of the sliced ​​wafer and does not surround the chamfered portion on the outer periphery of the sliced ​​wafer, thereby making it possible to reliably and quickly peel off the protective member from the sliced ​​wafer in the peeling step without leaving the protective member on the outer periphery of the sliced ​​wafer. [Brief description of the drawings]

[0012] [Figure 1] 4 is a side cross-sectional view showing a sheet placement step in the method for forming a protective member according to the present invention. FIG. [Diagram 2] 5(a) and 5(b) are side cross-sectional views showing a liquid resin supplying step in the method for forming a protective member according to the present invention. [Diagram 3] 4 is a side cross-sectional view showing a spreading step in the method for forming a protective member according to the present invention. FIG. [Figure 4] 4 is a side cross-sectional view showing a resin self-weight expansion step in the method for forming a protective member according to the present invention. FIG. [Diagram 5] 4 is a side cross-sectional view showing a curing step in the method for forming a protective member according to the present invention. FIG. [Figure 6] FIG. 6 is an enlarged detailed view of part A in FIG. 5. [Figure 7] 10 is a side cross-sectional view showing a grinding process (first grinding step) on the other surface (the surface on which the protective member is not formed) of the sliced ​​wafer. FIG. [Figure 8] 10(a) to 10(c) are side cross-sectional views showing a process of peeling off the protective member. [Figure 9] FIG. 8(b) is an enlarged detailed view of part B in FIG. 8(a). [Figure 10] FIG. 8(c) is an enlarged detailed view of part C in FIG. [Figure 11] 1 is a side cross-sectional view showing a state before one surface (the surface from which the protective member has been peeled off) of the sliced ​​wafer is ground. [Figure 12] FIG. 12 is an enlarged detailed view of part D in FIG. [Figure 13] 10 is a side cross-sectional view showing a grinding process (a second grinding step) of one surface (a surface from which a protective member has been peeled off) of the sliced ​​wafer. FIG. [Figure 14] FIG. 2 is a cross-sectional side view of a double-sided ground wafer. [Figure 15] FIG. 15 is an enlarged detailed view of a portion E in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. The method for forming a protective member according to the present invention is a method for forming a protective member P (see FIG. 5) on one surface of a sliced ​​wafer WS cut from a single crystal ingot of silicon or the like, 1) Sheet placement process 2) Liquid resin supply process 3) Spreading process 4) Resin self-weight expansion process 5) Curing process By carrying out the above steps in this order, a protective member P is formed on one surface WS1 (the lower surface in FIGS. 5 and 6) of a sliced ​​wafer WS, as shown in Fig. 5 and 6. Below, 1) a sheet arrangement step, 2) a liquid resin supply step, 3) a spreading step, 4) a resin self-weight expansion step, and 5) a curing step will be described in this order.

[0014] 1) Sheet placement process: The sheet arrangement step is a step of arranging a thin, transparent sheet S having translucency toward the upper surface of the case 10, as shown in Fig. 1. The sheet S is rectangular and larger than the sliced ​​wafers WS, and its outer periphery protrudes radially outward from the outer periphery of the sliced ​​wafers WS. Furthermore, as shown in Fig. 6, both surfaces of the sliced ​​wafers WS before grinding have warping and undulations.

[0015] Here, the case 10 is configured such that the upper surface of a cylindrical side wall 11 is covered with an extension table 12 made of transparent glass having optical transparency, and the lower surface of the side wall 11 is covered with a bottom plate 13 to form a space in which a plurality of (eight in the illustrated example) UV lamps 14 that emit ultraviolet rays (UV) upward are housed. In this sheet arrangement step, a sheet S having one end gripped by a gripper 15 is supplied and set on the flat extension table 12 of the case 10. In this embodiment, as described later, the protective member P is composed of the sheet S and liquid resin r (see FIGS. 5 and 6), but the protective member P may be composed of only the liquid resin r, in which case this sheet arrangement step is unnecessary.

[0016] 2) Liquid resin supply process: 2(a), the liquid resin supplying step is a step of dripping liquid resin r from a nozzle 30a opening downward above the case 10 toward the center of the sheet S, and supplying a small amount of liquid resin r from a nozzle 30b opening upward to the center of one surface WS1 (the lower surface in FIG. 2(a)) of a sliced ​​wafer WS held by suction on the lower surface of the holding table 20. Note that, although an ultraviolet-curing resin is used as the liquid resin r in this embodiment, other liquid resins such as a thermosetting resin may also be used.

[0017] 2, a disk-shaped holding table 20 can be raised and lowered by a lifting mechanism 21, and a porous member 20a is incorporated in the lower center of the holding table 20. The porous member 20a is connected to a suction source 23 by a pipe 22, and an on-off valve V1 is provided in the pipe 22. When the on-off valve V1 is opened to connect the porous member 20a to the suction source 23, a negative pressure is generated in the porous member 20a, and the sliced ​​wafers WS are attracted by the negative pressure and held on the lower surface of the holding table 20.

[0018] The holding table 20, which holds the sliced ​​wafers WS on its lower surface by suction, is located above the case 10, and as shown in FIG. 2(a), a horizontally extending arm 30 is disposed between the holding table 20 and the case 10. Here, the arm 30 is formed with a nozzle 30a opening toward the center of the sheet S placed on the extension table 12 and a nozzle 30b opening upward toward the center of the sliced ​​wafers WS held on the holding table 20, and these nozzles 30a and 30b are connected to a lower pump 33 and an upper pump 34 via resin supply paths 31 and 32 formed in the arm 30, respectively. These lower pump 33 and upper pump 34 are connected to a resin tank 35, and liquid resin r is stored in the resin tank 35. The arm 30 can be raised and lowered and moved horizontally by a moving mechanism 36.

[0019] In this liquid resin supply process, the liquid resin r stored in the resin tank 35 is supplied by the lower pump 33 to the nozzle 30a via the resin supply path 31 of the arm 30, and a predetermined amount of liquid resin r is dripped from the nozzle 30a toward the center of the sheet S placed on the extension table 12, while the liquid resin r in the resin tank 35 is supplied by the upper pump 34 to the nozzle 30b via the resin supply path 32 of the arm 30, and is supplied from the nozzle 30b toward the center of one side (the lower side in Figure 2) WS1 of the sliced ​​wafer WS held on the holding table 20.

[0020] 2(b), the center of the liquid resin r dropped onto the center of the sheet S placed on the expansion table 12 becomes depressed, but in the pushing and spreading process described later, the shortage of the liquid resin r in the depressed portion of the liquid resin r on the sheet S is replenished by a small amount of liquid resin r supplied to and attached to the center of the sliced ​​wafer WS. The outer periphery of the sliced ​​wafer WS is chamfered into a circular arc shape to form a chamfered portion R.

[0021] 3) Expansion process: 3, the spreading step is a step of spreading out the liquid resin (ultraviolet-curable resin) r dropped onto the sheet S in the liquid resin supplying step, and in this spreading step, the holding table 20 is lowered by the lifting mechanism 21, and the sliced ​​wafers WS held by suction on the lower surface WS1 of the holding table 20 are pressed against the liquid resin r on the sheet S, spreading out the liquid resin r to a uniform thickness. Note that in this spreading step, as described above, the shortage of the liquid resin r dropped onto the center of the sheet S in the liquid resin supplying step, causing a depression in the center, is replenished by a small amount of liquid resin r supplied to and attached to the center of the sliced ​​wafers WS.

[0022] Thus, the pressing load and pressing amount (height of the holding table 20) of the liquid resin r on the sheet S by the sliced ​​wafer WS in the spreading step are set to values ​​such that the liquid resin r to be spread does not reach the chamfered portion R formed on the outer periphery of the sliced ​​wafer WS, but is spread over the entire surface of the radially inner portion of the chamfered portion R on one surface WS1 (the lower surface in FIG. 3) of the sliced ​​wafer WS. Therefore, the liquid resin r does not reach the chamfered portion R on the outer periphery of the sliced ​​wafer WS and does not surround the chamfered portion R.

[0023] 4) Resin self-weight expansion process: In the resin self-weight expanding step, when the liquid resin r is spread over the entire surface of the radially inner part of the chamfered portion R of one surface WS1 of the sliced ​​wafer WS (the lower surface in FIG. 3) in the previous spreading step, the on-off valve V1 is opened to cut off the connection between the porous member 20a and the suction source 23, releasing the suction holding force of the holding table 20, and the lifting mechanism 21 raises the holding table 20 to separate it from the sliced ​​wafer WS, as shown in FIG. 4. Then, the pressure acting on the liquid resin r spread over one surface WS1 of the sliced ​​wafer WS (the lower surface in FIG. 4) becomes the weight of the sliced ​​wafer WS only, and the liquid resin r is maintained in a state of being expanded up to just before the chamfered portion R on the outer periphery of the sliced ​​wafer WS.

[0024] 5)Curing process: In the curing step, when the liquid resin r spread on one side WS1 of the sliced ​​wafer WS in the previous resin weight step is further spread by the weight of the sliced ​​wafer WS, the multiple UV lamps 14 in the case 10 are turned on as shown in Fig. 5. Then, ultraviolet light (UV) emitted upward from each UV lamp 14 passes through the transparent extension table 12 and the sheet S and is irradiated onto the liquid resin r, and the liquid resin r is cured. As a result of the liquid resin r being cured in this manner, a protective member P is formed on one side (the lower surface in Fig. 5) of the wafer W. Note that the surface (the lower surface in Fig. 5) of the protective member P formed by the cured resin r and the sheet S is a flat surface that fits the flat upper surface of the extension table 12 of the case 10, but as shown in Fig. 6, warping and waviness remain on both sides (the upper and lower surfaces in Fig. 6) of the sliced ​​wafer WS.

[0025] After the above steps, the protective member P is formed on the entire radially inner surface of the chamfered portion R of one surface WS1 of the sliced ​​wafer WS. 6) First grinding process 7) Peeling process 8) Second grinding process By grinding both surfaces of the sliced ​​wafers WS through the above steps in sequence, wafers W having flat surfaces and a predetermined thickness (see FIGS. 14 and 15) are manufactured. Hereinafter, 6) the first grinding step, 7) the peeling step, and 8) the second grinding step will be described in sequence with reference to FIGS.

[0026] 6) First grinding process: The first grinding process is a process of grinding the other side WS2 of the sliced ​​wafer WS (the side on which the protective member P is not formed), and in this first grinding process, as shown in Figure 7, the sliced ​​wafer WS is held on the holding surface of the chuck table 40 with the protective member P (sheet S) facing down, and the other side WS2 (the upper surface in Figure 7) of the sliced ​​wafer WS held on the holding surface of the chuck table 40 is ground by the grinding stone 50b of the grinding wheel 50.

[0027] Here, the chuck table 40 is a disk-shaped member, and a porous member 40a is incorporated in the center of the upper part thereof. The porous member 40a is connected to a suction source 42 via a pipe 41, and an on-off valve V2 is provided in the pipe 41. Therefore, when the on-off valve V2 is opened to connect the porous member 40a to the suction source 42, a negative pressure is generated in the porous member 40a, and the sliced ​​wafers WS are sucked and held by the holding surface of the chuck table 40 with the sheet S (protective member P) facing down by the negative pressure. The chuck table 40 is rotatable about a vertical rotation axis CL1 (not shown), and is rotated at a predetermined speed by a drive source (not shown) in the direction of the arrow in FIG. 7.

[0028] The grinding wheel 50 is detachably attached to a disk-shaped mount 52 attached to the lower end of a vertical spindle 51, and is composed of a disk-shaped base 50a and a plurality of grinding stones 50b attached in an annular shape to the lower surface of the base 50a. The spindle 51, the mount 52, and the grinding wheel 50 are rotated at a predetermined speed in the direction of the arrow shown in the figure (the same direction as the rotation direction of the chuck table 40) around the rotation axis CL2 of the spindle 51 by a spindle motor (not shown), and can be raised and lowered by a lifting mechanism 53.

[0029] In the first grinding step, the chuck table 40 is rotated at a predetermined speed in the direction of the arrow by a rotating mechanism (not shown) together with the sliced ​​wafer WS about the rotation axis CL1, and the grinding wheel 50 is rotated at a predetermined speed about the rotation axis CL2 by a spindle motor (not shown) in a state where the circumscribing circle of the grinding stone 50b passes through the center of the sliced ​​wafer WS. When the grinding wheel 50 is lowered by the lifting mechanism 53 by a predetermined grinding allowance from this state, the other surface WS2 (upper surface in FIG. 7) of the sliced ​​wafer WS on which the protective member P is not formed is ground by the grinding stone 50b. As a result, the warp or waviness (see FIG. 6) remaining on the other surface WS2 of the sliced ​​wafer WS is removed, and the other surface WS2 of the sliced ​​wafer WS is made flat as shown in FIG. 9. During grinding of the sliced ​​wafers WS, grinding water (pure water) is supplied to the contact point (processing point) between the sliced ​​wafers WS and the grinding wheel 50b to remove frictional heat generated at the processing point, suppressing a temperature rise at the processing point, and washing away grinding chips generated by grinding.

[0030] 7) Peeling process: In the peeling process, the other surface WS2 of the sliced ​​wafer WS (the surface on which the protective member is not formed) is ground to a flat surface in the previous first grinding process, and then the protective member P formed on one surface WS1 of the sliced ​​wafer WS is peeled off from the sliced ​​wafer WS.

[0031] In this embodiment, as a method for peeling the protective member P from the sliced ​​wafer WS, a method is adopted in which a force is applied in a direction in which the protective member P is easily peeled off to peel the protective member P. That is, as shown in FIG. 8(a), an end of a sheet S of the protective member P formed on one surface (lower surface in FIG. 8(a)) WS1 of the sliced ​​wafer WS whose other surface WS2 (upper surface in FIG. 8(a)) has been ground in the first grinding step is held by a clamper 60 as shown in FIG. 8(b), and the clamper 60 is pulled in the arrow direction (diagonally downward) in which the protective member P is easily peeled off to peel the protective member P from the sliced ​​wafer WS. The sliced ​​wafer WS from which the protective member P has been peeled off is shown in FIG. 8(c), but the one surface SW1 (lower surface in FIG. 9(c)) of the sliced ​​wafer WS from which the protective member P has been peeled off still has warping and waviness as shown in FIG. 10.

[0032] In this embodiment, the liquid resin r on the sheet S is pressed by the sliced ​​wafer WS and pressed by the sliced ​​wafer WS in the spreading step, and the pressing load and pressing amount (height of the holding table 20) are controlled so that the liquid resin r spread by one side WS1 of the sliced ​​wafer WS does not reach the chamfered portion R formed on the outer periphery of the sliced ​​wafer WS. Therefore, the liquid resin r is spread over the entire surface of the radially inner part of the chamfered portion R on one side WS1 of the sliced ​​wafer WS (lower surface in FIG. 3 ) of the sliced ​​wafer WS, and the liquid resin r does not surround the chamfered portion R on the outer periphery of the sliced ​​wafer WS. Therefore, in the peeling step, the protective member P can be peeled off from the sliced ​​wafer WS reliably and in a short time without leaving the protective member P on the outer periphery of the sliced ​​wafer WS. Furthermore, when the protective member P is peeled off, no part of the protective member P is left behind on the chamfered portion R of the sliced ​​wafer WS.

[0033] As a method for peeling the protective member P from the sliced ​​wafer WS, there are known a method for dissolving and removing the protective member P with a solvent, a method for deforming and peeling the protective member P by irradiating it with radiation such as light, and a method for immersing the protective member P in hot water at 60°C to 90°C to swell and peel the protective member P, and the protective member P may be peeled off from the sliced ​​wafer WS by these methods. Also, the protective member P may be peeled off from the sliced ​​wafer WS by grinding and removing the protective member P with a grinding wheel 50b.

[0034] 8) Second grinding process: The second grinding step is a step of grinding one surface (the surface on which the protective member P was formed) of the sliced ​​wafer WS from which the protective member P was peeled off in the preceding peeling step, and in this second grinding step, the sliced ​​wafer WS is held on the holding surface of the chuck table 40 with the other surface (flat surface ground in the first grinding step) WS2 facing down, as shown in Fig. 11. In the sliced ​​wafer WS held on the chuck table 40 in this manner, as shown in Fig. 12, the sliced ​​wafer WS is held on the holding surface of the chuck table 40 with the other flat surface WS2 (lower surface in Fig. 12) of the sliced ​​wafer WS ground in the first grinding step in close contact with the holding surface of the chuck table 40 (upper surface of the porous member 40a), and warping and waviness remain on one surface WS1 of the sliced ​​wafer WS (upper surface in Fig. 12 from which the protective member P was peeled off).

[0035] In the second grinding step, as shown in Fig. 13, one surface WS1 (upper surface in Fig. 13) of the sliced ​​wafer WS is ground by the grinding wheel 50 in the same manner as in the first grinding step. That is, the chuck table 40 is rotated at a predetermined speed in the direction of the arrow in Fig. 13 together with the sliced ​​wafer WS by a rotation mechanism (not shown), and the grinding wheel 50 is rotated at a predetermined speed about the rotation axis CL2 by a spindle motor (not shown) in a state in which the circumscribing circle of the grinding wheel 50b passes through the center of the sliced ​​wafer WS, and the grinding wheel 50 is lowered by a predetermined grinding allowance by the lifting mechanism 53. Then, one surface WS1 (upper surface in Fig. 13) of the sliced ​​wafer WS on which the protective member P was formed is ground by the grinding wheel 50b. As a result, a wafer W having a predetermined thickness with both sides ground as shown in Fig. 14 is obtained, and both sides W1 and W2 of this wafer W become flat planes with no warping or waviness as shown in Fig. 15. Note that in this second grinding step as well, grinding water (pure water) is supplied to the contact point (processing point) between the sliced ​​wafer WS and the grinding wheel 50b during grinding of the sliced ​​wafer WS, so that frictional heat generated at the processing point is removed to suppress a temperature rise at the processing point, and grinding chips generated by grinding are washed away.

[0036] Alternatively, without carrying out the above-mentioned peeling step, the protective member P may be peeled off from the sliced ​​wafer WS by grinding the protective member P with the grinding wheel 50b, and then one surface WS1 (upper surface in Figure 13) of the sliced ​​wafer WS may be ground with the grinding wheel 50b in the same manner as in the first grinding step.

[0037] As is clear from the above description, according to the present invention, it is possible to obtain the effect of being able to reliably peel off the protective member P from the sliced ​​wafers WS in a short time with a simple configuration, without leaving the protective member P on the sliced ​​wafers WS.

[0038] In the above embodiment, liquid resin r is supplied to a sliced ​​wafer WS having a chamfered portion R formed on its outer periphery and then spread out, but a chamfered portion R may also be formed on the outer periphery of the sliced ​​wafer WS after the liquid resin r has been spread and hardened.

[0039] In addition, the present invention is not limited to the application of the embodiments described above, and various modifications are possible within the scope of the claims and the technical ideas described in the specification and drawings. [Explanation of symbols]

[0040] 10: case, 11: side wall of the case, 12: extension table, 13: bottom plate of the case, 14: UV lamp, 15: gripper, 20: holding table, 20a: porous member, 21: lifting mechanism, 22: piping, 23: suction source, 30: arm, 30a, 30b: nozzles, 31, 32: resin supply passage, 33: upper pump, 34: lower pump, 35: resin tank, 36: moving mechanism, 40: chuck table, 40a: porous member, 41: piping, 42: suction source, 50: grinding wheel, 50a: base, 50b: grinding stone, 51: spindle, 52: mount, 53: lift mechanism, 60: clamper, CL1: Rotation axis of the chuck table, CL2: Rotation axis of the grinding wheel, P: Protective material, r: Liquid resin, R: Protective material, S: Sheet, V1, V2: Opening and closing valves, W: Wafer, W1: one side of the wafer, W2: the other side of the wafer, WS: sliced ​​wafer, WS1: one side of the sliced ​​wafer, WS2: the other side of the sliced ​​wafer

Claims

[Claim 1] A method for forming a protective member, comprising the steps of: spreading a liquid resin over the entire surface of one surface of a sliced ​​wafer sliced ​​from an ingot and hardening the resin by applying an external stimulus to the liquid resin when the sliced ​​wafer is produced by grinding both surfaces of the sliced ​​wafer; a liquid resin supplying step of supplying a predetermined amount of liquid resin to the center of the upper surface side of the extension table which spreads the liquid resin; a spreading step of relatively moving the sliced ​​wafer held on a holding table arranged opposite to the extension table in a direction approaching the extension table, and spreading the liquid resin by the sliced ​​wafer from the center of the sliced ​​wafer toward the outside in the radial direction to just before the outer periphery; a curing step of applying an external stimulus to the liquid resin after separating the holding table from the sliced ​​wafers to cure the liquid resin; Equipped with A method for forming a protective member, characterized in that in the spreading step, if a chamfered portion is formed on the outer peripheral edge of the sliced ​​wafer, the liquid resin is spread over the entire surface of one side up to the chamfered portion, and if no chamfered portion is formed on the outer peripheral edge of the sliced ​​wafer, the liquid resin is spread over the entire surface of one side up to the outer peripheral side of the sliced ​​wafer.

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