TW201903876A - Wafer processing method capable of suppressing processing defects caused by cutting end portion of protective tape - Google Patents

Abstract

The present invention provides a wafer processing method capable of suppressing processing defects caused by the cutting end portion of protective tape, which cuts into a wafer and rotates the wafer for performing circular cutting on the wafer. The wafer processing method includes: an adhering step for adhering a protective tape onto the wafer; a holding step for holding the wafer on a stage while having the protective tape as the upper surface; and, a processing step, which utilizes the cutter to cut into the outer edge of the wafer along with the outer edge of the protective tape to a predetermined depth and rotates the wafer for at least 360 degrees. The wafer processing method further includes a cutting trench forming step for forming the cutting trenches at a plurality of positions on the outer edge of the protective tape by an arbitrary processing mechanism before performing the processing step.

Description

Wafer processing method

FIELD OF THE INVENTION The present invention relates to a method of processing a wafer that is subjected to a circular dicing process on a wafer.

Background of the Invention In recent years, with the thinning and miniaturization of electronic equipment, wafers have been required to be ground to be thinner, for example, to 100 μm or less. Further, conventionally, in order to prevent cracking or dust generation in the manufacturing process, the wafer is chamfered on the outer periphery thereof. Therefore, when the wafer is ground to be thin, the chamfered portion of the outer circumference is formed into a blade shape (檐 shape). When the chamfered portion of the outer circumference of the wafer is formed into a blade edge shape, there is a problem that the wafer is broken due to the occurrence of a defect in the outer circumference.

In order to solve this problem, a method of processing a wafer in which a circular groove is formed from the front side of the outer peripheral portion of the wafer and then grinding the back surface of the wafer has been proposed (see, for example, Patent Document 1). Prior Technical Literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2010-245254

SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION The processing method of the wafer shown in the above-mentioned Patent Document 1 or the like has a case where a protective tape called BG (Back Grinding) tape is attached to the front surface of the wafer, and From this side of the protective tape, a circular groove is formed by cutting. In this case, the wafer processing method shown in Patent Document 1 produces a cutout portion of the elongated protective tape because the protective tape is not cut and runs toward the outer peripheral side of the wafer. The cutout of the protective tape is formed around the circumference of the wafer, and because it is long, it cannot be washed out by the usual cleaning mechanism. Therefore, there has been a problem that the cutout portion of the protective tape is followed by the holding table or the wheel cover, or adhered to the upper surface of the wafer to cause a vacuum vaccum error or the like during washing. As described above, the processing method of the wafer described in Patent Document 1 may cause a processing failure due to the cutout of the protective tape.

The present invention has been made in view of the above problems, and an object of the invention is to provide a method for processing a wafer which can suppress processing defects caused by protecting a cutout portion of a tape. Means to solve the problem

In order to solve the above problems and achieve the object, the wafer processing method of the present invention is to perform a circular cutting process on a wafer by cutting a dicing blade into a wafer and rotating the wafer, and processing the wafer. The method is characterized by: having: attaching a step of attaching a protective tape to the wafer; maintaining a step of holding the protective tape as an upper surface to hold the wafer on the holding table; and processing steps to cause the cutting blade to The outer edge of the circle and the outer edge of the protective tape are cut to a predetermined depth, and the wafer is rotated at least 360 degrees. The wafer processing method further includes a cutting groove forming step in which the cutting groove forming step is performed. Before the step is performed, the cutting groove is formed at a plurality of locations on the outer edge of the protective tape by an arbitrary processing mechanism. Effect of the invention

In the method for processing a wafer according to the present invention, since a plurality of cutting grooves are formed at the outer edge portion of the protective tape, the effect of preventing the length of the cutout portion of the tape from being wound around the processing portion can be prevented. The condition of the part.

MODE FOR CARRYING OUT THE INVENTION The embodiments (embodiments) for carrying out the invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Further, among the constituent elements described below, those having ordinary knowledge in the technical field can be easily conceived or substantially identical. Further, the configurations described below can be combined as appropriate. Further, various configurations may be omitted, substituted, or changed without departing from the spirit and scope of the invention.

[Embodiment 1] A method of processing a wafer according to Embodiment 1 of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing a wafer to be processed by a method of processing a wafer according to the first embodiment.

The processing method of the wafer according to the first embodiment is a method of processing the wafer 200 shown in FIG. 1, and is a method of removing the front side 201 side of the outer edge portion of the wafer 200, and is also a unit for dividing the wafer 200 into individual pieces. 202 method. The wafer 200 to be processed by the wafer processing method of the first embodiment is a disk-shaped semiconductor wafer having ruthenium as a substrate or an optical element wafer having sapphire, SiC (tantalum carbide) or the like as a substrate. As shown in FIG. 1, the wafer 200 is formed with elements 202 in a plurality of regions defined by a grid-shaped dividing line 203 formed on the front surface 201.

Next, an example of the cutting device 1 used in the method of processing a wafer according to the first embodiment will be described. FIG. 2 is a perspective view showing a configuration example of a cutting device used in the method of processing a wafer according to the first embodiment.

The cutting device 1 is a device for performing a so-called edge trimming process on the wafer 200, and the wafer 200 is subjected to a circular cutting process by cutting the cutting blade 22 into the wafer 200 and rotating the wafer 200, and The front side 201 side of the outer edge portion of the wafer 200 covers the entire circumference for removal. In the first embodiment, the dicing apparatus 1 covers a region (hereinafter referred to as a trimming region) 210 in which the front surface 201 side of the outer edge portion of the wafer 200 is removed over the entire circumference, and is a broken line and a wafer 200 shown in FIG. The outer edges of the wafers 200 are located on the outer peripheral side of the wafer 200 and cover the entire circumference to make the width 211 of the wafer 200 in the radial direction constant.

As shown in FIG. 2, the cutting device 1 includes a holding table 10 for sucking and holding the wafer 200 with the holding surface 11 and a cutting unit 20 for processing the edge of the wafer 200 held on the holding table 10; The X-axis moving unit 30 moves the holding table 10 and the cutting unit 20 in the X-axis direction parallel to the horizontal direction; the Y-axis moving unit 40 causes the holding table 10 and the cutting unit 20 to be parallel to the horizontal direction and the X-axis. The Z-axis moving unit 50 relatively moves the holding table 10 and the cutting unit 20 in the Z-axis direction orthogonal to both the X-axis direction and the Y-axis direction; the imaging unit 60; And control unit 100.

The holding table 10 is formed in a disk shape formed of porous ceramics or the like, and is connected to a vacuum suction source (not shown) through a vacuum suction path (not shown), and the suction is placed on the holding surface. The wafer 200 on the 11 is thereby held. Further, the holding table 10 is rotated about the axis parallel to the Z-axis direction by the rotation driving source 12.

The X-axis moving unit 30 is a machining feed mechanism that feeds the holding table 10 in the X-axis direction by moving the holding table 10 together with the rotation drive source 12 in the X-axis direction. The Y-axis moving unit 40 is an index feeding mechanism that feeds the holding stage 10 by indexing by moving the cutting unit 20 in the Y-axis direction. The Z-axis moving unit 50 is a cutting feed mechanism that cuts the cutting unit 20 into the feed by moving the cutting unit 20 in the Z-axis direction. The X-axis moving unit 30, the Y-axis moving unit 40, and the Z-axis moving unit 50 are each provided with a conventional ball screw 31, 41, a conventional pulse motor 32, 42 and a conventional guide rail 33, 43, the ball screw 31, 41 is rotatably disposed about an axis, and the pulse motors 32, 42 rotate the ball screws 31, 41 around the axis, and the guides 33, 43 are to hold the holding table 10 or the cutting unit 20 in the X-axis direction, Supported in a freely movable manner in the Y-axis direction or the Z-axis direction.

The cutting unit 20 includes a spindle motor, a spindle housing 21, and a cutter 22, which are rotated about an axis parallel to the Y-axis direction. The spindle housing 21 accommodates the spindle motor and is supported by the Y-axis. The moving unit 40 and the Z-axis moving unit 50 are moved in the Y-axis direction and the Z-axis direction, and the cutting blade 22 is mounted on the spindle motor. The cutting blade 22 is a cutting grindstone formed into an extremely thin annular shape, and is rotated by an axis of the spindle parallel to the Y-axis direction while being supplied with cutting water while being held by the holding table 10 The wafer 200 is subjected to a cutting knife for cutting. Further, as shown in Fig. 2, the cutting device 1 is a cutting device including two cutting units 20, that is, a double spindle, that is, a so-called facing double type cutting device.

The imaging unit 60 is a unit for photographing the wafer 200 held by the holding stage 10, and is disposed at a position side by side with the cutting unit 20 in the X-axis direction. In the first embodiment, the imaging unit 60 is attached to the spindle housing 21. The imaging unit 60 is constituted by a CCD camera that captures the wafer 200 held on the holding stage 10.

The control unit 100 is a unit that controls each of the above-described constituent elements of the cutting device 1 and causes the cutting device 1 to perform a processing operation on the wafer 200. The control unit 100 has a computer that can execute a computer program, such as a CPU (central processing unit), having a computing processing device, a storage device, and an input/output interface device, wherein the storage device has ROM (read only memory) or RAM (random access memory, random access memory) memory. The arithmetic processing unit of the control unit 100 executes a computer program stored in the ROM on the RAM and generates a control signal for controlling the cutting device 1. The arithmetic processing unit of the control unit 100 outputs the generated control signals to the respective constituent elements of the cutting device 1 through the input/output interface device. Further, the control unit 100 is connected to a display unit (not shown) or an input unit, which is constituted by a liquid crystal display device or the like that displays a state of a machining operation, an image, or the like, which is registered by an operator. Use when processing content information, etc. The input unit is composed of at least one of a touch panel, a keyboard, and the like provided on the display unit.

Next, a method of processing a wafer according to the first embodiment will be described. Fig. 3 is a flow chart showing a method of processing a wafer in the first embodiment. 4 is a perspective view showing a attaching step of a method of processing the wafer shown in FIG. 3. Fig. 5 is a side view showing a holding step of a method of processing the wafer shown in Fig. 3. Fig. 6 is a plan view showing an outline of a cutting step of the method of processing the wafer shown in Fig. 3; Fig. 7 is a cross-sectional view showing the outer edge portion of the wafer after the cutting step of the wafer processing method shown in Fig. 3; Fig. 8 is a plan view showing an outline of a processing procedure of a method of processing the wafer shown in Fig. 3. 9 is a side view of the wafer after the processing steps of the method of processing the wafer shown in FIG. 3. Fig. 10 is a side view showing a grinding step of a method of processing the wafer shown in Fig. 3. Fig. 11 is a side view showing the wafer after the DAF attaching step of the method of processing the wafer shown in Fig. 3.

The wafer processing method (hereinafter, abbreviated as the processing method) is performed by cutting the dicing blade 22 into the wafer 200 and rotating the wafer 200 around the axis parallel to the Z-axis direction. The processing method of cutting processing. As shown in FIG. 3, the processing method includes an attaching step ST1, a holding step ST2, a cutting groove forming step ST3, a processing step ST4, a grinding step ST5, and a DAF attaching step ST6.

The attaching step ST1 is a step of attaching the protective tape 220 shown in FIG. 4 to the wafer 200. In the first embodiment, as shown in FIG. 4, in the attaching step ST1, a protective tape 220 is attached to the front surface 201 of the wafer 200, wherein the front surface 201 of the wafer 200 has been formed on each of the dividing lines 203. A dividing groove 213 is formed from the front surface 201 side to a predetermined depth 212 (shown in Fig. 5, which corresponds to the depth of the finished product thickness of each element 202). In the first embodiment, the protective tape 220 is formed in a circular shape having the same size as the wafer 200. The protective tape 220 is provided with a base material layer 221 composed of a synthetic resin, and a paste layer 222 disposed on the base material layer 221 and attached to the front surface 201 of the wafer 200. After the attaching step ST1, the processing method proceeds to the holding step ST2.

The holding step ST2 is a step of holding the protective tape 220 on the upper surface to hold the wafer 200 on the holding stage 10. In the holding step ST2, the operator operates the input unit to log the processed content information to the control unit 100, and the operator sets the protective tape 220 to the upper surface as shown in FIG. 5 to place the wafer 200 on the holding. In the case of the surface 11, and the operator has made an instruction to start the machining operation, the control unit 100 drives the vacuum suction source to suck and hold the wafer 200 to the holding table 10. As described above, in the holding step ST2, the holding table 10 is the wafer 200 to which the protective tape 220 is attached to the front surface 201, and the protective tape 220 is placed on the upper surface to be held. After the processing method is maintained in step ST2, the processing is performed to the cutting groove forming step ST3.

The cutting groove forming step ST3 is a step of forming the cutting groove 230 shown in FIG. 6 at a plurality of outer edges of the protective tape 220 by the cutting unit 20, which is an arbitrary processing mechanism, before the execution of the processing step ST4. In the cut groove forming step ST3, the control unit 100 moves the holding stage 10 toward the lower side of the photographing unit 60 by the X-axis moving unit 30, and causes the photographing unit 60 to photograph the wafer 200, thereby performing calibration.

Moreover, the control unit 100 positions the cutting unit 20 by the X-axis moving unit 30, the Y-axis moving unit 40, the Z-axis moving unit 50, and the rotational driving source 12 according to the processing content information, the calibration result, and the like. On the outer edge portion of the wafer 200 of the holding stage 10. The control unit 100 lowers the cutting unit 20 by the Z-axis moving unit 50, and cuts the cutting blade 22 into the protective tape 220 on the outer edge portion of the wafer 200, as shown in FIG. 6, on the outer edge of the protective tape 220. The cutting groove 230 that penetrates the protective tape 220 is formed in the portion. When the cutting unit 20 is raised by the Z-axis moving unit 50, the control unit 100 rotates the rotation drive source 12 to the holding stage 10 at a predetermined angle in accordance with the processing content information, and forms the cutting groove 230 in the same manner as the one. In other words, the cutting groove 230 penetrates at least the outer edge portion of the protective tape 220 so as to cover the base material layer 221 and the paste layer 222.

In the first embodiment, as shown in FIG. 7, the cutting groove 230 removes a part of the substrate of the wafer 200. However, the protective tape 220 may be passed through without removing the substrate of the wafer 200. Further, in the first embodiment, the cutting groove 230 is formed with the cutting groove 230 in a state in which the cutting blade 22 and the outer edge of the protective tape 220 are parallel to each other. However, in the present invention, the cutting groove 230 may be cut. The blade 22 intersects with a tangent to the outer edge of the protective tape 220 to form the cutting groove 230.

Further, in the first embodiment, the cutting groove 230 is cut from the outer edge of the protective tape 220 toward the center of the protective tape 220, and the outer edge of the protective tape 220 is cut out. In the first embodiment, the cutting groove 230 is formed at eight positions at equal intervals in the circumferential direction of the protective tape 220 and the outer edge portion of the wafer 200. However, the cutting groove 230 is not limited thereto, and is formed at least at one position. can. Further, the cutting groove 230 is a distance 231 between the position of the cutting groove 230 closest to the center of the protective tape 220 and the outer edge of the protective tape 220, and is formed as the trimming region 210 when only the protective tape 220 is cut. When the protective tape 220 is cut together with the wafer 200, the width 211 or more is formed at a position within the width 211. In the first embodiment, the cutting groove 230 is formed at a position where the distance 231 is equal to the width 211 of the trimming region 210 of the trimming region 210. In this manner, in the cutting groove forming step ST3, the control unit 100 of the cutting device 1 performs the circular cutting process in the performing processing step ST4, and the protective tape is formed by causing the cutting unit 20 to form the cutting groove 230. The 220 attached to the trimming area 210 is cut into a plurality of pieces. The machining method proceeds to the processing step ST4 after the cutting groove forming step ST3.

In the processing step ST4, the cutting blade 22 is cut from the front surface 201 to the outer edge portion of the wafer 200 together with the outer edge portion of the protective tape 220 to a predetermined depth 212, and the wafer 200 is rotated about the axis by at least 360 degrees to The trimming region 210 at the outer edge portion of the wafer 200 is removed from the front surface 201 by a predetermined depth 212, and the wafer 200 is subjected to edge trimming. In the processing step ST4, the control unit 100 positions the two cutting blades 22 for trimming by the X-axis moving unit 30, the Y-axis moving unit 40, and the Z-axis moving unit 50 according to the processing content information, the calibration result, and the like. After the region 210, the cutting unit 20 is lowered in the Z-axis direction, and the rotary cutter 12 is rotated about the axis around the holding table 10 while the cutter blade 22 is cut into the predetermined depth 212 at the outer edge portion of the wafer 200. In the first embodiment, in the processing step ST4, the control unit 100 rotates the holding table 10 by 360 degrees around the axis, that is, one rotation, but in the present invention, it is not limited to one rotation. It is the number of turns that it is rotated to process the content information. In the processing step ST4, the cutting unit 20 cuts the outer edge portion of the wafer 200 and the outer edge portion of the protective tape 220 to a predetermined depth 212 in a state where the holding table 10 is rotated at least 360 degrees. Round cutting is performed as of here. Further, in the processing step ST4, as shown in FIGS. 8 and 9, the outer edge portion of the wafer 200 is removed by a predetermined depth 212 from the front surface 201 side.

In the processing step ST4, when the control unit 100 performs edge trimming on the wafer 200, the cutting unit 20 is raised to a position sufficiently far away from the wafer 200 and the protective tape 220, and the holding stage 10 is moved to the holding step ST2. After the position where the intermediate wafer 200 is placed, the suction holding of the holding table 10 is released. Then, the processing method is carried out to the grinding step ST5. In the processing method of the first embodiment, the cutting device 1 is used in the holding step ST2, the cutting groove forming step ST3, and the processing step ST4, and the same cutting blade is used in the cutting groove forming step ST3 and the processing step ST4. 22 is formed to cut the trench 230 and perform edge trimming on the wafer 200.

The grinding step ST5 is a step of grinding the back side 204 of the wafer 200 to thin the wafer 200 to the finished thickness of the element 202 and dividing the wafer 200 into individual elements 202. In the grinding step ST5, as shown in FIG. 10, the grinding device 70 sucks and holds the front surface 201 of the wafer 200 on the work chuck 71 via the protective tape 220, and rotates the work chuck 71 about the axis. The grinding stone 73 of the grinding unit 72 is rotated about the axis and brought into contact with the back surface 204 of the wafer 200 for grinding. In the grinding step ST5, the grinding device 70 grinds the wafer 200 until the dividing groove 213 is exposed on the back surface 204. The grinding step ST5 is performed by the grinding until the dividing groove 213 is exposed to the back surface 204, and the wafer 200 is divided into individual elements 202. After the grinding step ST5, the processing method proceeds to the DAF attaching step ST6.

The DAF attaching step ST6 is a step of attaching a DAF (Die Attach Film) 240 to the element 202 in a state in which it is attached to the protective tape 220 as shown in FIG. The DAF 240 is configured by disposing an acrylic or rubber-based paste layer on a substrate formed of an epoxy resin, an acrylic resin, a synthetic rubber, or a polyimide. After the DAF attaching step ST6, the DAF 240 may be divided into each element 202 by cutting processing, laser ablation processing, or expansion processing, and the element 202 is removed from the protective tape 220.

As described above, in the processing method of the first embodiment, before the execution of the processing step ST4 of performing the edge trimming, the protective tape 220 is attached to the front surface 201 of the wafer 200, and a processing method of edge trimming is performed for each of the protective tapes 220. In the DAF attaching step ST6, when the protective tape 220 is not protruded from the outer edge of the wafer 200 to the outer peripheral side, the DAF 240 is attached to the protective tape 220 or the like, and the like. A processing method that hinders the attachment of the DAF 240.

In the processing method according to the first embodiment, since the cutting groove forming step ST3 of forming the cutting groove 230 at the outer edge portion of the protective tape 220 is performed before the execution of the processing step ST4, the removed protective tape can be removed in the processing step ST4. The remaining portion of 220 is formed to be cut by cutting the groove 230 in advance, and the length of the cutout of the protective tape 220 can be suppressed. Therefore, the processing method can quickly move the cutout of the protective tape 220 away from the holding table 10 by cutting the water flow of water or the like. As a result, the processing method can suppress the case where the cutout of the protective tape 220 is followed by (or wound around) the holding stage 10, the rotary driving source 12, the X-axis moving unit 30, and the wafer 200 on the holding stage 10, and the like, and The processing failure of the wafer 200 is suppressed.

Further, in the processing method according to the first embodiment, since the cutting groove 230 can be formed at a position where the distance 231 is equal to or larger than the width 211 of the trimming region 210, the protective tape 220 removed in the processing step ST4 can be cut. The remaining portion is formed in a state of being surely cut by cutting the groove 230.

Further, in the processing method according to the first embodiment, since the same cutting blade 22 is used in the cutting groove forming step ST3 and the processing step ST4, and the same cutting device 1 proceeds from the holding step ST2 to the processing step ST4, it is possible to suppress The time required for the conveyance of the wafer 200 or the like can be suppressed, and the time required for the processing of the wafer 200 can be suppressed for a long period of time.

[Embodiment 2] A method of processing a wafer according to Embodiment 2 of the present invention will be described with reference to the drawings. Fig. 12 is a flow chart showing a method of processing a wafer in the second embodiment. In the same portions as those in the first embodiment, the same reference numerals will be given to the same portions, and the description thereof will be omitted.

The processing method of the wafer according to the second embodiment (hereinafter, abbreviated as the processing method) is different from the first embodiment in the timing of performing the cutting groove forming step ST3 as shown in FIG. 12, and the holding step ST2 and processing are performed. The processing apparatus of the first embodiment is the same as the processing method of the first embodiment except that the different processing apparatuses of the cutting device 1 of the step ST4 perform the groove forming step ST3. Specifically, in the processing method of the second embodiment, the cutting groove forming step ST3 is performed after the attaching step ST1 is performed, and after the cutting groove forming step ST3 is performed, the holding step ST2 and the processing step ST4 are sequentially performed. The grinding step ST5 and the DAF attach step ST6.

In the cutting groove forming step ST3 of the processing method according to the second embodiment, a laser processing apparatus that uses ablation processing for the protective tape 220 or a cutting device different from the cutting device 1 is used as the processing device, and a laser beam irradiation unit is used. Or the cutting unit acts as a processing mechanism. As described above, in the present invention, the cutting groove 230 may be formed by any processing means in the cutting groove forming step ST3. In the holding step ST2 and the processing step ST4 of the processing method of the second embodiment, the cutting device 1 is used in the same manner as in the first embodiment.

In the processing method of the second embodiment, the cutting groove forming step ST3 for forming the cutting groove 230 at the outer edge portion of the protective tape 220 is performed before the execution of the processing step ST4, so that the protection removed in the processing step ST4 can be suppressed. The length of the cut-away portion of the tape 220. As a result, the processing method can suppress the case where the cutout of the protective tape 220 is followed by (or wound around) the holding stage 10, the rotary driving source 12, the X-axis moving unit 30, and the wafer 200 on the holding stage 10, and the like, and The processing failure of the wafer 200 is suppressed.

[Modification] A method of processing a wafer according to a modification of the first embodiment and the second embodiment of the present invention will be described with reference to the drawings. FIG. 13 is a side view showing a protective tape or the like which forms a cutting groove by a method of processing a wafer according to a modification of the present invention. The same components as those in the first embodiment and the second embodiment are denoted by the same reference numerals, and their description is omitted.

One of the phenomena of the elongate protective tape 220 resulting from the edge trimming of the wafer 200 from the side of the protective tape 220 is one of the phenomena, sometimes because the protective tape 220 can be attached to the wafer. A portion of the cut of 200, but the portion of the protective tape 220 that is not attached and floated from the wafer 200 will run toward the outside of the wafer 200 without being cut. The method of processing a wafer according to a modification (hereinafter, simply referred to as a processing method) is an effective example of suppressing the occurrence of the cutout portion of the elongated protective tape 220 caused by such a phenomenon. In the processing method according to the modification, the cutting groove 230 is formed on the outer peripheral side of the outer edge of the portion of the protective tape 220 attached to the flat front surface 201 of the wafer 200 (the position indicated by a little chain line in FIG. 13) 225). That is, the processing method of the modification is that the cutting groove 230 is formed to the chamfered portion 206 of the protective tape 220 which is not attached to the outer edge portion of the wafer 200, and is separated by a distance. The position 225 is overlapped with the chamfered portion 206 in the thickness direction.

In the processing method of the modified example, in the cutting groove forming step ST3 before the execution of the processing step ST4, the cutting groove 230 is formed so that the protective tape 220 is not attached to the chamfered portion 206 and overlaps in the thickness direction. In this position, the length of the cutout of the protective tape 220 removed in the processing step ST4 can be suppressed. As a result, the processing method can suppress the case where the cutout portion of the protective tape 220 is followed by the wafer 200 on the holding stage 10 or the holding stage 10, and the processing failure of the wafer 200 can be suppressed.

Further, according to the method for processing a wafer according to the first embodiment, the following cutting device can be obtained. (Supplementary Note 1) A cutting device that performs a circular cutting process on a wafer by cutting a dicing blade into a wafer and rotating the wafer, the cutting device having: a holding table for attaching the front surface a wafer with a protective tape to hold the protective tape as an upper surface; a cutting unit that causes the dicing blade to be attached to the outer edge of the wafer together with the protective tape in a state where the holding table is rotated at least 360 degrees The outer edge is cut to a predetermined depth to perform the circular cutting process; and the control unit controls each component, and the control unit causes the cutting unit to be outside the protective tape before performing the circular cutting process A cut groove is formed at a plurality of edges.

In the same manner as the wafer processing method of the first embodiment, since the cutting groove 230 is formed in the protective tape 220 before the edge trimming is performed, the cutout portion of the removed protective tape 220 can be formed into the edge trimming. The cutting groove 230 is cut in advance, and the length of the cutout of the protective tape 220 can be suppressed. Therefore, the processing method can quickly move the cutout of the protective tape 220 away from the holding table 10 by cutting the water flow of water or the like. As a result, the processing method can suppress the case where the cutout portion of the protective tape 220 is followed by the wafer 200 on the holding stage 10 or the holding stage 10, and the processing failure of the wafer 200 can be suppressed.

Furthermore, the present invention is not limited to the inventions of the above embodiments and modifications. That is, various modifications can be made without departing from the spirit and scope of the invention.

1‧‧‧ cutting device

10‧‧‧ Keeping the table

11‧‧‧ Keep face

12‧‧‧Rotary drive source

20‧‧‧Cutting unit

21‧‧‧ spindle housing

22‧‧‧Cutting knife

30‧‧‧X-axis mobile unit

31, 41‧‧‧ ball screw

32, 42‧‧‧ pulse motor

33, 43‧‧‧ rails

40‧‧‧Y-axis mobile unit

50‧‧‧Z-axis mobile unit

60‧‧‧ shooting unit

70‧‧‧ grinding device

71‧‧‧Working table

72‧‧‧ grinding unit

73‧‧‧ grinding grinding stone

100‧‧‧Control unit

200‧‧‧ wafer

201‧‧‧ positive

202‧‧‧ components

203‧‧‧ dividing line

204‧‧‧Back

206‧‧‧Chamfering

210‧‧‧Finished area

211‧‧‧Width

212‧‧‧Depth

213‧‧‧dividing trench

220‧‧‧Protection tape

221‧‧‧ substrate layer

222‧‧ ‧ paste layer

225‧‧‧ position

230‧‧‧ cut the ditch

231‧‧‧ distance

240‧‧‧DAF

ST1, ST2, ST3, ST4, ST5, ST6‧‧‧ steps

X, Y, Z‧‧ Direction

Fig. 1 is a perspective view of a wafer to be processed by a method of processing a wafer according to the first embodiment. FIG. 2 is a perspective view showing a configuration example of a cutting device used in the method of processing a wafer according to the first embodiment. Fig. 3 is a flow chart showing a method of processing a wafer in the first embodiment. 4 is a perspective view showing a attaching step of a method of processing the wafer shown in FIG. 3. Fig. 5 is a side view showing a holding step of a method of processing the wafer shown in Fig. 3. Fig. 6 is a plan view showing an outline of a cutting step of the method of processing the wafer shown in Fig. 3; Fig. 7 is a cross-sectional view showing the outer edge portion of the wafer after the cutting step of the wafer processing method shown in Fig. 3; Fig. 8 is a plan view showing an outline of a processing procedure of a method of processing the wafer shown in Fig. 3. 9 is a side view of the wafer after the processing steps of the method of processing the wafer shown in FIG. 3. Fig. 10 is a side view showing a grinding step of a method of processing the wafer shown in Fig. 3. Fig. 11 is a side view showing the wafer after the DAF attaching step of the method of processing the wafer shown in Fig. 3. Fig. 12 is a flow chart showing a method of processing a wafer in the second embodiment. Fig. 13 is a side view showing a protective tape or the like for forming a cutting groove by a method of processing a wafer according to a modification of the present invention.

Claims (1)

A method for processing a wafer by performing a circular cutting process on a wafer by cutting a dicing blade into a wafer and rotating the wafer, the wafer processing method characterized by: having: an attaching step, Attaching a protective tape to the wafer; maintaining a step of holding the protective tape as an upper surface to hold the wafer on the holding table; and processing steps such that the cutting edge of the wafer is adjacent to the outer edge of the protective tape The method of processing the wafer further includes a cutting groove forming step of cutting the wafer to a predetermined depth and rotating the wafer at least 360 degrees. The cutting groove forming step is performed by any processing mechanism before the processing step is performed. A cutting groove is formed at a plurality of points on the outer edge of the protective tape.