Grinding wheel attachment jig and use method of the same

Abstract

To provide a grinding wheel attachment jig which enables a grinding wheel to be attached to a flange so that a rotation axis of the flange forming grinding means precisely matches with a rotation axis of the grinding wheel.SOLUTION: A grinding wheel attachment jig includes cylindrical bodies 41, 42 which contact with an outer periphery of a grinding wheel and an outer periphery of a flange. The cylindrical bodies are formed with fastening parts 45 which fasten one end 41a and the other end 42a as seen in a circumferential direction of the cylindrical bodies 41, 42 to each other. The grinding wheel and the flange are housed in the cylindrical bodies 41, 42 and the one end 41a and the other end 42a of the cylindrical bodies 41, 42 are fastened by the fastening parts 45 to cause inner peripheries of the cylindrical bodies 41, 42 to contact with an outer periphery of the grinding wheel and an outer periphery of the flange closely and match a rotation axis of the flange with a rotation axis of the grinding wheel.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a grinding wheel mounting jig for use in a grinding device including a chuck table for holding a wafer and grinding means having a grinding wheel attached to a flange for grinding the wafer held on the chuck table, and a method for using the grinding wheel mounting jig. [Background technology]

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

[0003] The grinding device includes a chuck table for holding a wafer and a grinding means for grinding the back surface of the wafer held on the chuck table, and can grind the wafer to a desired thickness with high precision.

[0004] The present applicant has also proposed a technology in which the back surface corresponding to the device region formed on the front surface of the wafer is ground to form a ring-shaped reinforcing portion on the back surface corresponding to the peripheral excess region (see Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-057526 Summary of the Invention [Problem to be solved by the invention]

[0006] The technology described in the above-mentioned Patent Document 1 uses a grinding wheel having a diameter corresponding to the radius of the wafer and having a grinding stone fixed to an annular wheel, which is attached to a flange constituting the grinding means.

[0007] Then, a grinding wheel is positioned at the center of the back surface of the wafer held on the chuck table and inside the ring-shaped reinforcing portion to be formed, and the chuck table is rotated while the grinding wheel is rotated to grind the back surface corresponding to the device region of the wafer, thereby forming a ring-shaped reinforcing portion on the back surface corresponding to the outer peripheral excess region.

[0008] However, if the center of the rotation axis of the flange constituting the grinding means and the center of the rotation axis of the grinding wheel are misaligned when they are attached, there is a problem that a highly accurate ring-shaped reinforcing portion cannot be formed.Furthermore, when the grinding wheel for grinding the entire back surface of the wafer is attached to the flange, if the center of the rotation axis of the flange and the center of the rotation axis of the grinding wheel are misaligned when they are attached, there is a problem that the grinding wheel wobbles when it rotates, resulting in uneven grinding marks, which is undesirable.

[0009] The present invention has been made in consideration of the above facts, and its main technical object is to provide a grinding wheel mounting jig that can be mounted so that the rotational axis of the flange that constitutes the grinding means accurately coincides with the rotational axis of the grinding wheel, and that can form, for example, a ring-shaped reinforcing portion of a constant width with high precision on the outer periphery of the back side of the wafer, and that also solves the problem of the grinding wheel swinging during grinding, resulting in uneven grinding marks, and a method for using the grinding wheel mounting jig. [Means for solving the problem]

[0010] In order to solve the above-mentioned main technical problems, according to the present invention, there is provided a grinding wheel mounting jig for use in a grinding apparatus comprising a chuck table for holding a wafer, and grinding means having a flange on which a grinding wheel for grinding the wafer held on the chuck table is mounted, the grinding wheel mounting jig having a cylindrical body that contacts the outer periphery of the grinding wheel and the outer periphery of the flange, the cylindrical body having fastening portions that fasten one end and the other end in the circumferential direction of the cylindrical body, the grinding wheel and the flange being housed inside the cylindrical body, and the one end and the other end of the cylindrical body being fastened by the fastening portions, thereby bringing the inner periphery of the cylindrical body into close contact with the outer periphery of the grinding wheel and the outer periphery of the flange, and aligning the rotational axis of the flange with the rotational axis of the grinding wheel.

[0011] The cylindrical body may be provided with a hinge corresponding to the fastening portion. A support portion for supporting a grinding wheel is preferably formed at the bottom of the cylindrical body. The grinding wheel may be composed of annularly arranged grinding stones having a diameter corresponding to the radius of the wafer and an annular wheel supporting the grinding stones, and may be capable of grinding the back surface of the wafer and forming a ring-shaped reinforcing portion on the outer periphery of the wafer. It is preferable that the outer diameter of the grinding wheel is the same as the outer diameter of the flange.

[0012] According to the present invention, there is provided a method of using the above-mentioned grinding wheel mounting jig, comprising: a temporary fixing step of temporarily fixing the grinding wheel to the flange using a bolt insertion port formed in one of the grinding wheel or the flange and an internally threaded hole into which the external thread of a bolt inserted into the bolt insertion port formed in the other; a fastening step of positioning the inner periphery of the cylindrical body of the grinding wheel mounting jig with the outer periphery of the grinding wheel and the outer periphery of the flange and fastening the fastening parts to bring the inner periphery of the cylindrical body into close contact with the outer periphery of the grinding wheel and the outer periphery of the flange, thereby aligning the rotational axis of the flange with the rotational axis of the grinding wheel; an mounting step of screwing in the bolt to mount the grinding wheel to the flange; and a removal step of loosening the fastening parts to remove the grinding wheel mounting jig from the flange and the grinding wheel. [Effects of the Invention]

[0013] The grinding wheel mounting jig of the present invention makes it possible to mount the grinding wheel so that its rotational axis precisely coincides with that of the flange constituting the grinding means. A grinding wheel mounted by the grinding wheel mounting jig of the present invention can, for example, form a ring-shaped reinforcing portion of a constant width on the outer periphery of the back side of the wafer with high precision, thereby eliminating the problem of the grinding wheel swinging during grinding, resulting in uneven grinding marks.

[0014] Furthermore, according to the method of using the grinding wheel mounting jig of the present invention, it is possible to mount the grinding wheel so that the rotational axis of the flange constituting the grinding means and the rotational axis of the grinding wheel are accurately aligned, and by using a grinding wheel mounted according to the method of using the grinding wheel mounting jig of the present invention, it is possible to form, for example, a ring-shaped reinforcing portion of a constant width on the outer periphery of the back side of the wafer with high precision, thereby eliminating the problem of the grinding wheel swinging during grinding processing and resulting in uneven grinding marks. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is an overall perspective view of a grinding device suitable for use with the grinding wheel mounting jig of this embodiment. [Figure 2] 2(a) is a perspective view showing how a grinding wheel for grinding the entire back surface of a wafer is attached to the flange of the grinding device shown in FIG. 1, and FIG. 2(b) is a cross-sectional view of the grinding wheel shown in FIG. [Figure 3] FIG. 2(a) is a perspective view showing how a grinding wheel is attached to the flange of the grinding device shown in FIG. 1 to grind the back surface of the wafer corresponding to the device region and form a ring-shaped reinforcing portion on the outer periphery, and FIG. 2(b) is a cross-sectional view of the grinding wheel shown in FIG. 1(a). [Figure 4] 1A is a perspective view of the grinding wheel mounting jig of the present embodiment, and FIG. 1B is a perspective view showing the state in which the fastening portion of the grinding wheel mounting jig shown in FIG. 1A is fastened. [Figure 5](a) is an oblique view showing an embodiment of the temporary fixing process in the method of using the grinding wheel mounting jig of this embodiment, and (b) is an oblique view showing the state in which the grinding wheel is temporarily fixed to the flange as a result of the temporary fixing process shown in (a). [Figure 6] (a) is an oblique view showing an embodiment of the fastening process in the method of using the grinding wheel mounting jig of this embodiment, and (b) is an oblique view showing the state in which the rotation axis of the flange and the rotation axis of the grinding wheel are aligned by the fastening process shown in (a). [Figure 7] 1 is a perspective view showing an embodiment of a mounting step in a method of using the grinding wheel mounting jig of this embodiment. FIG. [Figure 8] FIG. 10 is a perspective view showing an embodiment of a removal step in a method of using the grinding wheel mounting jig of this embodiment. [Figure 9] 2 is a perspective view of a wafer to be processed by the grinding apparatus shown in FIG. 1. [Figure 10] 10 is a perspective view showing an embodiment in which the back surface of the wafer shown in FIG. 9 is ground and a ring-shaped reinforcing portion is formed on the outer periphery of the wafer. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a grinding wheel mounting jig configured according to the present invention and a method of using the grinding wheel mounting jig will be described in detail with reference to the accompanying drawings.

[0017] FIG. 1 shows an overall perspective view of a grinding apparatus 1 suitable for carrying out the method of using the grinding wheel mounting jig of this embodiment.

[0018] The grinding apparatus 1 has a roughly rectangular parallelepiped housing 2, which contains a grinding means 3 for grinding the back surface 10b of a wafer 10, which is a workpiece; a holding means 5 having a chuck table 51 for holding the wafer 10; a first cassette 6 arranged on the front side in the drawing for accommodating the wafer 10 before grinding; a second cassette 7 arranged on the other side in the X-axis direction in the drawing relative to the first cassette 6 for accommodating the wafer 10 after grinding; a temporary placement means 8 arranged adjacent to the first cassette 6 in the Y-axis direction in the drawing for aligning the center of the wafer 10; a cleaning device 9 arranged in a direction perpendicular to the wafer transport direction, a first transport means 11 that transports the wafers 10 stored in the first cassette 6 to the temporary storage means 8 and transports the wafers 10 cleaned in the cleaning device 9 to the second cassette 7, a second transport means 12 that transports the wafers 10 placed on the temporary storage means 8 and centered onto the chuck table 51 of the holding means 5 positioned at the load / unload position (the front side in the figure), a third transport means 13 that transports the wafers 10 after grinding from the chuck table 51 positioned at the load / unload position to the cleaning device 9, and a control means (not shown).

[0019] The grinding means 3 is mounted to be movable in the vertical direction on a pair of guide rails 22, 22 extending in the vertical direction on the inner surface of a support wall 21 erected on the rear end side of the device housing 2. The grinding means 3 includes a unit housing 31, a flange 33 disposed at the lower end of a rotary shaft 32 rotatably supported by the unit housing 31, a grinding wheel 34A (or 34B) (described in detail below) detachably mounted on the flange 33 and having a grinding stone disposed in an annular shape on the lower surface side, an electric motor 36 mounted on the upper end of the unit housing 31 for rotating the flange 33 together with the rotary shaft 32, and a movable base 38 for supporting the unit housing 31 via a support member 37.

[0020] The movable base 38 is provided with guided grooves that slidably fit onto the above-mentioned guide rails 22, 22, and supports the grinding means 3 so that it can move up and down. A through-hole is formed in the axis of the rotating shaft 32, penetrating the rotating shaft 32 and extending from the upper end 32a to the underside of the flange 33. Grinding water W supplied from a grinding water supply means (not shown) is introduced via the upper end 32a, and the grinding water W is supplied from the underside of the flange 33 to the area where grinding is to be performed.

[0021] The illustrated grinding apparatus 1 includes a grinding feed means 39 that raises and lowers a movable base 38 of the grinding means 3 along the guide rails 22. The grinding feed means 39 includes a pulse motor 39a, a male-threaded rod 39b that is disposed vertically parallel to the guide rails 22, 22, rotatably supported on the support wall 21, and driven to rotate by the pulse motor 39a, and a female-threaded block (not shown) that is attached to the movable base 38 and threadedly engages with the male-threaded rod 39b. The male-threaded rod 39b is driven forward and reverse by the pulse motor 39a to move the grinding means 3 in the Z-axis direction (up and down). Furthermore, an operation panel 14 is provided on the front side of the apparatus housing 2, where the first transport means 11 is disposed, for issuing grinding instructions to the control means and specifying grinding conditions.

[0022] The holding means 5, which includes a chuck table 51, is equipped with a cover table 52, and the chuck table 51 is disposed in the center of the cover table 52 so as to protrude upward. The chuck table 51 has a holding surface for holding the wafer 10, and the holding surface is made of a breathable material. The chuck table 51 is rotated by a rotary drive source (not shown). Also, a moving means (not shown) for moving the chuck table 51 in the Y-axis direction indicated by the arrow Y is disposed within the device housing 2, and moves the chuck table 51 between a carry-in / out position on the front side in the Y-axis direction and a grinding position directly below the grinding means 3.

[0023] In addition to the above-mentioned configuration, a non-contact or contact thickness measuring means (not shown) is provided to measure the thickness of the wafer 10 held on the chuck table 51 and ground by the grinding means 3.

[0024] The control means is configured by a computer and includes a central processing unit (CPU) that performs calculations according to a control program, a read-only memory (ROM) that stores the control program, etc., a readable and writable random access memory (RAM) that temporarily stores detected values, calculation results, etc., an input interface, and an output interface. The control means is connected to each operating unit such as the electric motor 36 of the grinding means 3, the grinding feed means 39, the first conveying means 11, the second conveying means 12, the third conveying means 13, etc., as well as the thickness measuring means, etc.

[0025] Different types of grinding wheels can be attached to the flange 33 of the grinding means 3. FIG. 2(a) shows how a grinding wheel 34A used to grind the entire back surface 10b of the wafer 10 is attached to the flange 33, and FIG. 2(b) shows a cross-sectional view of the grinding wheel 34A. The cylindrical flange 33 formed at the lower end of the rotating shaft 32 has four bolt insertion holes 33a formed at equal intervals (90°) around the circumference, a support surface 33b on the lower surface, and an outer periphery 33c. The grinding wheel 34A includes a plurality of grinding stones 342A arranged in an annular shape and an annular wheel 341A that supports the grinding stones 342A. The grinding wheel 34A has an attachment surface 34Aa that forms the upper surface, female threaded holes 34Ab into which bolts 36 for attaching the grinding wheel 34A are threaded, an outer periphery 34Ac, and an opening 34Ad formed in the center. The four female screw holes 34Ab are formed at equal intervals (90°) in the circumferential direction corresponding to the bolt insertion holes 33a. The outer diameter of the grinding wheel 34A in this embodiment is set to be the same as the outer diameter of the flange 33.

[0026] The grinding wheel 34A can be attached to the flange 33 by aligning the upper mounting surface 34Aa of the grinding wheel 34A against the support surface 33b of the flange 33 and threading the bolts 36 through the bolt insertion holes 33a of the flange 33 and into the female threaded holes 34Ab. The four bolt insertion holes 33a formed in the flange 33 are so-called through holes and are slightly larger in diameter than the bolts 36. This means that there is a margin of error in the mounting accuracy when threading the bolts 36 into the female threaded holes 34Ab of the grinding wheel 34A to mount the wheel. Therefore, if the wheel is mounted in this state, the rotational axis of the flange 33 and the rotational axis of the grinding wheel 34A may be misaligned. Therefore, as described below, the grinding wheel 34A is mounted to the flange 33 using a grinding wheel mounting jig 40 configured according to the present invention, as shown in FIG. 4. The configuration of the grinding wheel mounting jig 40 and how to use the grinding wheel mounting jig 40 will be described in detail later.

[0027] 3(a) and 3(b), for example, can be mounted on the grinding apparatus 1 of this embodiment. The illustrated grinding wheel 34B is a grinding wheel for forming a ring-shaped reinforcing portion in the outer peripheral excess region on the back surface of the wafer 10, and includes a plurality of grinding stones 342B arranged in an annular shape and having a diameter corresponding to the radius of the wafer 10, and an annular wheel 341B that supports the grinding stones 342B on the underside.

[0028] FIG. 3(a) shows how the grinding wheel 34B is attached to the flange 33. The flange 33 formed at the lower end of the rotating shaft 32 is the same as the flange 33 described with reference to FIG. 2, and therefore a detailed description thereof will be omitted. As can be seen from FIGS. 3(a) and 3(b), the grinding wheel 34B has an attachment surface 34Ba that is attached to the support surface 33b of the flange 33, an internally threaded hole 34Bb into which a bolt 36 for attaching the grinding wheel 34B to the flange 33 is threaded, an outer periphery 34Bc, and an opening 34Bd formed in the center. Four internally threaded holes 34Bb are formed at equal intervals (90°) around the circumference, corresponding to the bolt insertion openings 33a formed in the flange 33. The outer diameter of the grinding wheel 34B in this embodiment is set to be the same as the outer diameter of the flange 33.

[0029] The grinding wheel 34B can be attached to the flange 33 by aligning the attachment surface 34Ba of the grinding wheel 34B with the support surface 33b of the flange 33 and inserting the bolts 36 into the bolt insertion holes 33a of the flange 33 and screwing them into the female threaded holes 34Bb. As with the attachment of the grinding wheel 34A described above, the four bolt insertion holes 33a formed in the flange 33 are so-called through holes and are formed slightly larger in diameter than the bolts 36. This means that there is some play in the attachment accuracy when the bolts 36 are screwed into the female threaded holes 34Bb of the grinding wheel 34B to attach them. Therefore, when the bolts 36 are screwed into the female threaded holes 34Bb of the grinding wheel 34B through the four bolt insertion holes 33a formed in the flange 33 to attach them, the rotational axis of the flange 33 may be misaligned with the rotational axis of the grinding wheel 34B. Therefore, a grinding wheel 34B is attached to the flange 33 using a grinding wheel attachment jig 40 configured according to the present invention as shown in FIG. 4 (described in detail later).

[0030] In the grinding means 3 described above, the bolt insertion opening 33a is formed on the flange 33 side as a through hole through which the bolt 36 passes, and the female threaded holes 34Ab and 34Bb are arranged on the grinding wheels 34A and 34B sides. However, it is also possible to form the bolt insertion openings on the grinding wheels 34A and 34B sides and the female threaded holes on the flange 33 side, and to attach the grinding wheels 34A and 34B to the flange 33 using the bolt 36.

[0031] As described above, the outer diameters of the grinding wheels 34A and 34B in this embodiment are the same as the outer diameter of the flange 33, and the grinding wheels 34A and 34B can be mounted so that the rotational axis of the flange 33 coincides with the rotational axis of the grinding wheels 34A and 34B using the grinding wheel mounting jig 40 described below.

[0032] A grinding wheel mounting jig 40 of this embodiment will be described with reference to Figures 4(a) and (b). The grinding wheel mounting jig 40 accommodates any one of the grinding wheels and the flange 33 described above and includes halves 41 and 42 constituting a cylindrical body that contacts the outer periphery of the grinding wheel and the outer periphery 33c of the flange 33. The halves 41 and 42 are connected by a hinge 43 as shown in Figure 4(a). The cylindrical body includes a fastening portion 45 that fastens one end 41a and the other end 42a of the cylindrical body that are not connected by the hinge 43. The illustrated fastening portion 45 includes a connecting portion 41b formed at the one end 41a and a connecting portion 42b disposed at the other end 42a. A through-hole 41c is formed in the connecting portion 41b, and an internally threaded hole 42c is formed in the connecting portion 42b. By inserting the illustrated bolt 40a into the through-hole 41c and screwing the bolt 40a into the internally threaded hole 42c of the connecting portion 42b to fasten the one end 41a and the other end 42a, a cylindrical body can be formed as shown in FIG. 4(b). The inner surface of the cylindrical body coincides with the outer periphery of the flange 33 and the outer periphery of the grinding wheel. The cylindrical body can be made of either metal or resin, but can be made of stainless steel, for example. When the cylindrical body is made of resin, it is preferable to fasten the connecting portions 41b and 42b, which form the fastening portion 45, with bolts and nuts.

[0033] In the grinding wheel mounting jig 40 described above, the hinge 43 is disposed on the opposite side corresponding to the fastening portion 45, but the present invention is not limited to this. For example, if the cylindrical body is made of a highly flexible material, the halves 41 and 42 may be formed integrally in advance without being connected by the hinge 43. Furthermore, in the above embodiment, the fastening portion 45 is formed by the connecting portion 41b and the connecting portion 42b and fastened by the bolt 40a. However, the present invention is not limited to this. Instead of the connecting portion 41b and the connecting portion 42b, another structure capable of fastening the one end 41a and the other end 42a of the cylindrical body may be used. For example, a snap lock may be disposed between the one end 41a and the other end 42a to form the fastening portion of the present invention.

[0034] 4(a) and 4(b), a support portion 44 is disposed below the half portions 41 and 42 that constitute the cylindrical body, and supports the grinding wheel attached to the flange 33. The support portions 44 extend horizontally toward the center of the cylindrical body formed by the half portions 41 and 42, and are disposed at equal intervals around the circumference; in this embodiment, four support portions 44 are disposed at 90° intervals (the two in the front are not visible). Note that the support portion 44 can also be omitted.

[0035] The grinding wheel mounting jig 40 of this embodiment has roughly the above-mentioned configuration, and a method of using the grinding wheel mounting jig 40 will be specifically described with reference to Figures 5 to 8. Note that the following description will be given for the case where the grinding wheel 34B is mounted on the flange 33 of the grinding means 3.

[0036] (Temporary fixing process) 5(a), when the grinding wheel 34B is mounted on the flange 33 of the grinding means 3 using the grinding wheel mounting jig 40, bolts 36 are first inserted into the four bolt insertion holes 33a formed in the flange 33, the mounting surface 33Ba of the grinding wheel 34B is brought close to the support surface 33b constituting the underside of the flange 33, the bolts 36 are positioned in the female threaded holes 34Bb formed in the grinding wheel 34B, and the bolts 36 are rotated in the direction indicated by arrow R1 to screw in and temporarily fix the grinding wheel 34B to the flange 33. During this temporary fixation, as shown in FIG. 5(b), the support surface 33b of the flange 33 and the mounting surface 34Ba of the grinding wheel 34B are not in close contact with each other, leaving a gap S, and the rotational axis of the grinding wheel 34B is displaced relative to the rotational axis of the flange 33 depending on the play (gap) of the bolts 36 in the bolt insertion holes 33a.

[0037] (Fascinating process) After the temporary fixing step is performed as described above, the grinding wheel mounting jig 40 is prepared, and as shown in Fig. 6(a), in a state where the fastening by the fastening portion 45 is not completely completed, i.e., in a state where one end 41a of one half 41 constituting the cylindrical body is separated from the other end 42a of the other half 42, the inner periphery of the cylindrical body of the grinding wheel mounting jig 40 is positioned to face the outer periphery 34Bc of the grinding wheel 34B and the outer periphery 33c of the flange 33. Next, the bolt 40a described above is inserted through the through hole 41c of one connecting portion 41b constituting the fastening portion 45 and screwed into the female threaded hole 42c of the other connecting portion 42b, as shown in Fig. 6(b), to fasten the one end 41a and the other end 42a together. At this time, the grinding wheel 34B is supported and lifted from below by the support portions 44 formed on the grinding wheel mounting jig 40, and the support surface 33b of the flange 33 and the mounting surface 34Ba of the grinding wheel 34B are positioned in close or nearly close contact with each other. As a result, the bolts 36 are raised above the upper surface of the flange 33, as shown in the figure. Then, by fastening the one end 41a and the other end 42a of the cylindrical body with the fastening portions 45 of the grinding wheel mounting jig 40 as described above, the inner peripheries 41c and 42c of the cylindrical body are brought into close contact with the outer periphery 34Bc of the grinding wheel 34B and the outer periphery 33c of the flange 33, and the rotational axis of the flange 33 and the rotational axis of the grinding wheel 34B can be aligned.

[0038] (Installation process) Once the rotational axis of the flange 33 and the rotational axis of the grinding wheel 34B have been aligned by the above-mentioned fastening process, as shown in Figure 7, the bolt 36 is further rotated in the direction indicated by arrow R1 while the grinding wheel mounting jig 40 is still attached, and the bolt 36 is screwed in, thereby completely fastening and mounting the grinding wheel 34B to the flange 33 in close contact, thereby completing the mounting process.

[0039] (Removal process) After the above-mentioned mounting process has been carried out, as shown in FIG. 8, the bolt 40a of the fastening portion 45 is loosened, and the half portions 41 and 42 that make up the cylindrical body are separated from the flange 33 and the grinding wheel 34B to complete the removal process of removing the grinding wheel mounting jig 40, and the mounting of the grinding wheel 34B to the flange 33 is completed.

[0040] According to the grinding wheel mounting jig 40 and the method of using the grinding wheel mounting jig 40 described above, even if there is some play in the mounting accuracy between the flange 33 constituting the grinding means 3 and the grinding wheel 34B mounted on the flange 33, it is possible to completely align the outer periphery 34Bc of the grinding wheel 34B with the outer periphery 33c of the flange 33, and as a result, the grinding wheel 34B can be mounted on the flange 33 with the rotational axis of the flange 33 and the rotational axis of the grinding wheel 34B accurately aligned.

[0041] As described above, once the grinding wheel 34B is attached to the flange 33 using the grinding wheel attachment jig 40, a grinding process is carried out to form a ring-shaped reinforcing portion on the outer periphery of the back surface 10b of the wafer 10.

[0042] FIG. 9 shows details of a wafer 10 processed by the grinding process of this embodiment. As shown in the figure, the wafer 10 has a plurality of devices D formed on its surface 10a, partitioned by planned division lines L. The surface 10a of the wafer 10 is divided into a device region 10A in which the plurality of devices D are formed, and a peripheral surplus region 10B surrounding the device region 10A. Note that FIG. 9 depicts a circular division line 16 (shown by a two-dot chain line) that divides the device region 10A and the peripheral surplus region 10B, but the division line 16 is shown for convenience of explanation and is not actually drawn on the surface 10a of the wafer 10.

[0043] 9, a protective tape T is applied to the front surface 10a of the wafer 10, and as shown in the lower part of the figure, the protective tape T faces downward and the back surface 10b of the wafer 10 faces upward. The wafer 10 is transported to the holding means 5 of the grinding device 1, and as shown in Fig. 10, the wafer 10 is placed on the chuck table 51 of the holding means 5 with the back surface 10b of the wafer 10 facing upward, and is held by suction so that the center of the wafer 10 and the center of the chuck table 51 are aligned.

[0044] Next, as shown in FIG. 10, the chuck table 51 positioned at the grinding position is rotated in the direction indicated by arrow R2 at a predetermined rotational speed (e.g., 300 rpm), and the electric motor 36 is operated to rotate the rotary shaft 32 in the direction indicated by arrow R3 at a predetermined rotational speed (e.g., 6000 rpm). The grinding feed means 39 is then operated to lower the grinding means 3 in the direction indicated by arrow R4 at a predetermined grinding feed speed (e.g., 1 μm / sec). As described with reference to FIG. 3, a plurality of grinding stones 342B (not visible in FIG. 10) are annularly arranged on the underside of the grinding wheel 34B with a diameter corresponding to the radius of the wafer 10, and are brought into contact with the back surface 10b of the wafer 10. At this time, the grinding stones 342B pass through at least the center of rotation of the back surface 10b of the wafer 10 and are brought into contact with the portion of the back surface 10b corresponding to the device region 10A formed on the front surface 10a of the wafer 10, and are fed for grinding. As a result, as shown on the right side of Figure 10, the wafer 10 is thinned except for a ring-shaped reinforcing portion 17 of a desired width remaining in the region corresponding to the peripheral excess region 10B on the back surface 10b of the wafer 10, and a recess having a bottom thickness of, for example, 30 µm is formed in the region corresponding to the device region 10A. The thickness of the reinforcing portion 17 remains 700 µm, the same as the original thickness of the wafer 10. With this, the grinding process is completed.

[0045] In the above-described embodiment, the grinding wheel 34B is mounted on the flange 33 of the grinding means 3 using the grinding wheel mounting jig 40, and is mounted so that the rotation axis of the flange 33 and the rotation axis of the grinding wheel 34B are accurately aligned. This makes it possible to form a ring-shaped reinforcing portion 17 of a constant width with high precision on the outer periphery of the back surface 10b side of the wafer 10. Furthermore, this also solves the problem of the grinding wheel 34A swinging during grinding, resulting in uneven grinding marks.

[0046] In the above embodiment, an example has been described in which the grinding wheel 34B is mounted on the flange 33 of the grinding means 3 using the grinding wheel mounting jig 40, but the grinding wheel 34A can be mounted on the flange 33 by implementing a method of using the grinding wheel mounting jig 40 similar to that described above. The grinding wheel 34A is used to grind the entire back surface 10b of the wafer 10, and even when mounting such a grinding wheel 34A, by mounting the grinding wheel 34A on the flange 33 using the grinding wheel mounting jig 40, the rotational axis of the flange 33 and the rotational axis of the grinding wheel 34A can be aligned with high precision, thereby eliminating the problem of the grinding wheel 34A rotating together with the flange 33 swinging during grinding, resulting in uneven grinding marks.

[0047] In the above embodiment, the case where the outer diameter of the flange 33 and the outer diameter of the grinding wheel mounted on the flange 33 are the same has been described, but the grinding wheel mounting jig of the present invention can also be applied to cases where the outer diameter of the flange 33 and the outer diameter of the grinding wheel mounted on the flange 33 do not match. For example, if the outer diameter of the grinding wheel mounted on the flange 33 differs from the outer diameter of the flange 33, a stepped structure can be formed on the inner periphery of the cylindrical body of the grinding wheel mounting jig, with an upper region corresponding to the outer diameter of the flange 33 and a lower region corresponding to the outer diameter of the grinding wheel. By performing the fastening step in the method of using the grinding wheel mounting jig described above, the upper region of the cylinder can be brought into close contact with the flange 33 and the lower region of the cylinder can be brought into close contact with the outer diameter of the grinding wheel, thereby enabling the rotational axis of the flange 33 to be aligned with the rotational axis of the grinding wheel with high precision. [Explanation of symbols]

[0048] 1: Grinding device 2: Device housing 21:Supporting wall 22: Guide rail 3: Grinding method 31: Unit housing 32: Rotation axis 33: Flange 33a: Bolt insertion hole 33b: Support surface 33c: outer circumference 34A: Grinding wheel 34Aa: Mounting surface 34Ab: Female thread hole 34Bc:Outer circumference 34Bd:Aperture 341A: Wheel 342A: Grinding wheel 34B: Grinding wheel 34Ba: Mounting surface 34Bb: Female thread hole 34Bc:Outer circumference 34Bd:Aperture 341B: Wheel 342B: Grinding wheel 36: Electric motor 37: Support member 38: Mobile base 39: Grinding feed means 4: Grinding wheel mounting jig 41: Half part 41a: One side end 41b: Connection part 42:Half section 42a: Other side end 42b: Connection part 43: Hinge 44: Support part 45: Fastening part 5: Holding means 51: Chuck table 52: Cover table 6: First cassette 7: Second cassette 8: Temporary storage means 9: Cleaning equipment 10: Wafer 11: First transport means 12: Second transport means 13: Third transport means 14: Operation panel D:Device L: Planned division line W: Grinding water

Claims

1. A grinding wheel mounting jig for use in a grinding device including a chuck table for holding a wafer, and grinding means having a flange on which a grinding wheel for grinding the wafer held on the chuck table is mounted, a cylindrical body that contacts the outer periphery of the grinding wheel and the outer periphery of the flange, and a fastening portion that fastens one end and the other end in the circumferential direction of the cylindrical body is formed on the cylindrical body; The grinding wheel mounting jig accommodates the grinding wheel and the flange inside the cylindrical body, and fastens one end of the cylindrical body to the other end with the fastening portion, thereby bringing the inner periphery of the cylindrical body into close contact with the outer periphery of the grinding wheel and the outer periphery of the flange, thereby aligning the rotational axis of the flange with the rotational axis of the grinding wheel.

2. 2. The grinding wheel mounting jig according to claim 1, wherein the cylindrical body is provided with a hinge corresponding to the fastening portion.

3. 2. The grinding wheel mounting jig according to claim 1, wherein a support portion for supporting the grinding wheel is formed at the bottom of said cylindrical body.

4. The grinding wheel mounting jig described in claim 1 is composed of a grinding stone arranged in an annular shape and having a diameter corresponding to the radius of the wafer, and an annular wheel supporting the grinding stone, and is capable of grinding the back surface of the wafer and forming a ring-shaped reinforcing portion on the outer periphery of the wafer.

5. 2. The grinding wheel mounting jig according to claim 1, wherein the outer diameter of the grinding wheel is the same as the outer diameter of the flange.

6. A method for using the grinding wheel mounting jig according to any one of claims 1 to 5, comprising: a temporary fixing step of temporarily fixing the grinding wheel to the flange using a bolt insertion hole formed in one of the grinding wheel or the flange and an internally threaded hole into which an external thread of a bolt inserted into the bolt insertion hole formed in the other of the grinding wheel or the flange is threaded; a fastening step of positioning the inner periphery of the cylindrical body of the grinding wheel mounting jig on the outer periphery of the grinding wheel and the outer periphery of the flange, fastening the fastening portion, and bringing the inner periphery of the cylindrical body into close contact with the outer periphery of the grinding wheel and the outer periphery of the flange, thereby aligning the rotation axis of the flange with the rotation axis of the grinding wheel; a mounting step of mounting the grinding wheel on the flange by screwing the bolt; and a removing step of loosening the fastening portion to remove the grinding wheel mounting jig from the flange and the grinding wheel.

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