Method for manufacturing a standard wafer corresponding tray

Abstract

Provided is a manufacturing method for a standard wafer corresponding tray, which can properly handle wafers smaller than the standard wafers corresponding to a processing device. The method includes: a preparation step of preparing a plate-shaped object having the same shape as a standard wafer; a holding step of holding the plate-shaped object on a chuck table capable of rotation and linear movement; a circular recess processing step of positioning a rotating cutting tool on the upper surface of the plate-shaped object and cutting to a prescribed depth, rotating the chuck table to form a circular groove, and performing index feeding of the cutting tool in the radial direction of the chuck table to form a circular recess having a diameter corresponding to the diameter of a wafer (4) to be housed; and a linear groove processing step of positioning the cutting tool on an unprocessed region of the plate-shaped object and cutting to the same depth as the circular recess, linearly moving the chuck table to form a linear groove, performing index feeding of the cutting tool to form the linear groove, and forming the unprocessed region to the same depth as the circular recess.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a standard wafer tray, the standard wafer tray storing wafers smaller than the standard wafers corresponding to the processing device. Background Technology

[0002] A wafer with multiple devices such as ICs and LSIs formed on its front side by a pre-defined dicing line is diced into individual device chips by a dicing device. The resulting device chips are then used in electronic devices such as mobile phones and personal computers.

[0003] Processing devices, including various processing devices such as cutting devices and inspection devices for inspecting wafers, have worktables that correspond to the diameter of standardized wafers (see, for example, Patent Document 1), which makes it difficult to process wafers smaller than the standard.

[0004] Patent Document 1: Japanese Patent Application Publication No. 10-116802 Summary of the Invention

[0005] In view of the above facts, the objective of the present invention is to provide a method for manufacturing a standard wafer-compatible tray, which enables appropriate processing of wafers, even those smaller than the standard wafers corresponding to the processing device, in the processing device.

[0006] According to the present invention, a method for manufacturing a standard wafer-compatible tray is provided to solve the above-mentioned problems. That is, a method for manufacturing a standard wafer corresponding tray is provided, which holds wafers smaller than the standard wafers corresponding to the processing device. The method for manufacturing the standard wafer corresponding tray includes the following steps: a preparation step, in which a plate-shaped object with the same shape as the standard wafer is prepared; a holding step, in which the plate-shaped object is held on a chuck table that can rotate and move linearly; an annular recess machining step, in which a rotating cutting tool is positioned on the upper surface of the plate-shaped object and cuts into it to a predetermined depth, and the chuck table is rotated to form an annular groove, and the cutting tool is sequentially indexed and fed radially on the chuck table to form an annular recess with a diameter corresponding to the diameter of the wafer to be held; and a straight groove machining step, in which a cutting tool is positioned on the unprocessed area of ​​the plate-shaped object remaining inside the annular recess and cuts into it to the same depth as the annular recess, and the chuck table is moved linearly to form a straight groove, and the cutting tool is sequentially indexed and fed to form a straight groove, and the unprocessed area is formed to the same depth as the annular recess.

[0007] Preferably, when the thickness of the cutting edge of the cutting tool is set to W, the indexing feed rate is 0.8W to 0.9W. Preferably, the thickness of the cutting edge of the cutting tool is 0.5mm to 1.5mm.

[0008] The manufacturing method of the standard wafer corresponding tray of the present invention includes the following steps: a preparation step, in which a plate-shaped object with the same shape as a standard wafer is prepared; a holding step, in which the plate-shaped object is held on a chuck worktable that can rotate and move linearly; an annular recess machining step, in which a rotating cutting tool is positioned on the upper surface of the plate-shaped object and cuts into it to a predetermined depth, and the chuck worktable is rotated to form an annular groove, and the cutting tool is sequentially indexed and fed radially on the chuck worktable to form an annular recess with a diameter corresponding to the diameter of the wafer to be housed; and a straight groove machining step, in which a cutting tool is positioned on the unprocessed area of ​​the plate-shaped object remaining inside the annular recess and cuts into it to the same depth as the annular recess, and the chuck worktable is moved linearly to form a straight groove, and the cutting tool is sequentially indexed and fed to form a straight groove, and the unprocessed area is formed to the same depth as the annular recess. Therefore, using the tray manufactured by the method of the present invention, even wafers smaller than the standard wafers corresponding to the processing device can be properly processed in the processing device. Attached Figure Description

[0009] Figure 1 It is a three-dimensional view of a wafer and a plate that are smaller than the standard wafer corresponding to the processing device.

[0010] Figure 2 It is a three-dimensional diagram of the cutting device.

[0011] Figure 3 It is a perspective view showing the state of performing the annular recess machining process.

[0012] Figure 4 It is a three-dimensional diagram of a plate-shaped object with annular recesses.

[0013] Figure 5 This is a perspective view showing the state of performing the straight groove machining process.

[0014] Figure 6 yes Figure 1 The diagram shows a 3D view of the trays corresponding to the wafers and standard wafers.

[0015] Figure 7 (a) shows that Figure 6 The chip shown is stored in Figure 6 The diagram shown corresponds to the state of the standard wafer in the tray. Figure 7 (b) is Figure 7 (a) shows a cross-sectional view of the wafer and the standard wafer corresponding to the tray.

[0016] Figure 8 This is a perspective view showing the formation of a straight groove corresponding to the orientation plane of the outer periphery of the wafer during the annular recess processing step.

[0017] Figure 9 This is a perspective view showing the state in which a C-shaped groove corresponding to the arc-shaped portion of the outer periphery of the wafer is formed during the annular recess processing step.

[0018] Figure 10 It is a three-dimensional view of a wafer with an oriented plane and a standard wafer tray for storing the wafer.

[0019] Label Explanation

[0020] 2: Plate-shaped object; 2': Standard wafer corresponding tray; 4: Wafer; 12: Cutting device (an example of a processing device); 14: Chuck worktable; 16: Cutting tool; 44: Annular groove; 46: Annular recess; 48: Unprocessed area. Detailed Implementation

[0021] Hereinafter, a preferred embodiment of the method for manufacturing the standard wafer corresponding tray of the present invention will be described with reference to the accompanying drawings.

[0022] In the illustrated embodiment, a preparation process is first performed to prepare a plate-shaped object with the same shape as a standard wafer. The plate-shaped object prepared in the preparation process can be... Figure 1 The plate-shaped object 2 is shown in the diagram. The diameter D1 of the plate-shaped object 2 is the same as the diameter of a standard wafer corresponding to various processing devices, inspection devices, etc., such as 4 inches, 6 inches, 8 inches, etc. Furthermore, the thickness of the plate-shaped object 2 is the same as the thickness of the standard wafer, for example, it can be approximately 700 μm.

[0023] The material for plate 2 can be the same as that used for wafers smaller than standard wafers (e.g., silicon). Alternatively, plate 2 can be made of a suitable synthetic resin such as glass, ceramic, or polyethylene terephthalate (PET). Figure 1 As shown, a straight portion 2a is provided on the outer periphery of the plate-shaped object 2 in the illustrated embodiment, but a notch may also be formed. Alternatively, the plate-shaped object 2 may be a simple circle without the straight portion 2a or the notch.

[0024] exist Figure 1 The diagram also shows a wafer 4 in the shape of a circular plate, smaller than a standard wafer. The diameter D2 of wafer 4 is smaller than the diameter of a standard wafer corresponding to various processing apparatuses, inspection apparatuses, etc., and smaller than the diameter D1 of the plate 2. Wafer 4 can be formed from a suitable semiconductor material such as silicon. In the illustrated embodiment, the front side 4a of wafer 4 is divided into multiple rectangular regions by grid-like predetermined dividing lines 6, and devices 8 such as ICs and LSIs are formed in each of these rectangular regions. Furthermore, in... Figure 1 The outer periphery of the wafer 4 shown has a notch 10 indicating the crystal orientation of the wafer 4.

[0025] After the preparation process, a holding process is performed, in which the plate 2 is held on a chuck table that can rotate and move linearly. Then, an annular recess machining process is performed, in which a rotating cutting tool is positioned on the upper surface of the plate 2 and cuts into a specified depth, and the chuck table is rotated to form an annular groove. The cutting tool is then indexed and fed radially on the chuck table to form an annular recess with a diameter corresponding to the diameter D2 of the wafer 4 to be housed.

[0026] For example, the holding process and the annular recess machining process can be used Figure 2 The cutting device 12 shown is used to implement this. The cutting device 12 includes at least: a chuck table 14 for holding the workpiece; and a cutting unit 18 which has an annular cutting tool 16 rotatably capable of cutting the workpiece held by the chuck table 14.

[0027] A porous, circular suction chuck 20, connected to a suction unit (not shown), is disposed at the upper end of the chuck stage 14. The suction unit generates an attractive force on the upper surface of the suction chuck 20, thereby attracting and holding the workpiece placed on the upper surface of the suction chuck 20. Figure 2 As shown, multiple clamps 22 are arranged at circumferential intervals on the outer periphery of the chuck worktable 14.

[0028] The chuck table 14 rotates about an axis extending vertically and radially through the radial center of the suction chuck 20, centered by a motor (not shown), and is fed by a machining feed unit (not shown). Figure 2 The chuck table 14 moves linearly in the X-axis direction, as indicated by the middle arrow X. Thus, the chuck table 14 is configured to rotate and move linearly in the X-axis direction.

[0029] The cutting edge thickness of the cutting tool 16 in the cutting unit 18 can be 0.5mm to 1.5mm. Additionally, although not shown, the cutting unit 18 includes a motor that causes the cutting tool 16 to move along the Y-axis direction perpendicular to the X-axis direction. Figure 2 The cutting tool 16 rotates around the axis extending in the direction indicated by the middle arrow Y; the indexing feed unit indexes the cutting tool 16 in the Y-axis direction; and the feed-in unit feeds the cutting tool 16 in the Z-axis direction (which is perpendicular to both the X-axis and Y-axis directions). Figure 2 The feed is performed in the up-down direction indicated by the middle arrow Z. Furthermore, the XY plane defined by the X-axis and Y-axis directions is essentially horizontal.

[0030] The cutting device 12 also includes: a photographing unit 24 for photographing the workpiece held on the chuck worktable 14; a lifting and lowering box setting platform 28 for setting up a box 26 for storing multiple workpieces; a loading and unloading unit 32 for pulling out the workpiece before processing from the box 26 and moving it to the temporary placement table 30, and moving the processed workpiece positioned on the temporary placement table 30 into the box 26; a first conveying unit 34 for conveying the workpiece before processing from the box 26 to the temporary placement table 30 to the chuck worktable 14; a cleaning unit 36 ​​for cleaning the processed workpiece; and a second conveying unit 38 for conveying the processed workpiece from the chuck worktable 14 to the cleaning unit 36.

[0031] In the holding process of the illustrated embodiment, the plate-shaped object 2 stored in the box 26 is first pulled out by the loading / unloading unit 32 and temporarily placed on the temporary table 30. Next, the plate-shaped object 2 is transferred from the temporary table 30 to the chuck worktable 14 by the first conveying unit 34. With the rotation center of the chuck worktable 14 aligned with the radial center of the plate-shaped object 2, the plate-shaped object 2 is attracted and held on the chuck worktable 14. Furthermore, when the plate-shaped object 2 is processed by the cutting device 12, such as... Figure 2 As shown, the plate 2 can be attached to the scribe strip 42, which is fixed to the outer periphery of the annular frame 40, and the plate 2 is supported on the annular frame 40 by means of the scribe strip 42. In this case, the plate 2 is attracted and held on the chuck table 14 from the scribe strip 42 side, and the annular frame 40 is fixed by the clamp 22.

[0032] After the holding process, the annular recess machining process is performed. In the annular recess machining process, the chuck stage 14 is first moved below the imaging unit 24, and the imaging unit 24 takes an image of the plate-shaped object 2 from above to detect the area to be machined. Next, the chuck stage 14 is moved below the cutting unit 18, and the positional relationship between the plate-shaped object 2 and the cutting tool 16 is adjusted based on the image of the plate-shaped object 2 taken by the imaging unit 24. In the illustrated embodiment, the cutting tool 16 is positioned relative to the rotation center of the chuck stage 14 at a position corresponding to the radius of the wafer 4 to be housed.

[0033] Next, as Figure 3 As shown, the cutting tool 16 is lowered, and the cutting edge of the cutting tool 16, which is rotating in the direction indicated by arrow R1 at a predetermined rotational speed (e.g., 20,000 rpm), cuts into the upper surface of the plate 2 to a predetermined depth. Meanwhile, cutting water is supplied to the portion where the cutting edge of the cutting tool 16 cuts in, and the chuck table 14 is rotated in the direction indicated by arrow R2 at a predetermined rotational speed (e.g., 3° / second). This forms an annular groove 44 whose depth does not penetrate the plate 2. Figure 3The annular groove 44 shown is an annular groove 44 formed during the cutting process, and therefore is not shown as an annular shape, but it actually forms an annular groove without an end. In addition, the width of the annular groove 44 is of course a dimension equivalent to the thickness of the cutting edge of the cutting tool 16.

[0034] Next, after the cutting tool 16 is raised and leaves the plate 2, it is indexed radially inward towards the chuck table 14 by the indexing feed unit. When the thickness of the cutting edge of the cutting tool 16 is set to W, the indexing feed amount is preferably 0.8W to 0.9W. This reliably connects the initially formed annular groove 44 and the subsequently formed annular groove 44, preventing the formation of walls between adjacent annular grooves 44. Furthermore, by repeatedly forming the annular groove 44 and performing the indexing feed, as... Figure 4 As shown, an annular recess 46 with a diameter (outer diameter) corresponding to the diameter D2 of the wafer 4 to be housed is formed on the upper surface of the plate 2.

[0035] Furthermore, there is a minimum limit value for the diameter of the annular groove 44 that can be formed on the plate 2 by the cutting device 12. Therefore, the recess 46 formed in this process is annular, and a circular unprocessed area 48 remains on the radial inner side of the annular recess 46.

[0036] Furthermore, in the illustrated embodiment, the cutting tool 16 is indexed sequentially from the radially outer side to the inner side of the chuck table 14. However, it is also possible to do the opposite, with the cutting tool 16 being indexed sequentially from the radially inner side to the outer side of the chuck table 14. Additionally, compared to the case where the annular groove 44 is formed by indexing from the radially inner side to the outer side, the load acting on the cutting tool 16 during machining is smaller in the case where the annular groove 44 is formed by indexing from the radially outer side to the inner side. Therefore, it is preferable to perform the indexing feed from the radially outer side to the inner side.

[0037] After performing the annular recess machining process, a straight groove machining process is performed. The cutting tool 16 is positioned on the unmachined area 48 remaining inside the annular recess 46 of the plate 2 and cuts into the same depth as the annular recess 46. While providing cutting water to the cut portion, the chuck table 14 is moved linearly to form a straight groove. The cutting tool 16 is indexed and fed sequentially to form a straight groove, thereby forming the unmachined area 48 to the same depth as the annular recess 46.

[0038] The straight groove machining process can be performed using the cutting device 12 in the same way as the annular recess machining process. In the straight groove machining process, the chuck table 14 is first moved below the imaging unit 24, and the imaging unit 24 takes an image of the plate 2 from above to inspect the unmachined area 48 to be machined. Next, the chuck table 14 is moved below the cutting unit 18, and based on the image of the plate 2 taken by the imaging unit 24, the cutting tool 16 is positioned above the outer periphery of the unmachined area 48.

[0039] Next, as Figure 5 As shown, the cutting tool 16 is lowered, and the cutting edge of the cutting tool 16, rotating in the R1 direction at a predetermined rotational speed (e.g., 20,000 rpm), cuts into the outer periphery of the unmachined area 48 to the same depth as the annular recess 46. While providing cutting water to the cut portion, the chuck table 14 performs machining feed in the X-axis direction at a predetermined machining feed rate. This forms a straight groove in the unmachined area 48 to the same depth as the annular recess 46. In other words, the upper surface of the unmachined area 48 is removed by the amount of a straight groove to the same depth as the annular recess 46.

[0040] Next, after the cutting tool 16 is raised and leaves the plate 2, it is indexed by the indexing feed unit in a direction perpendicular to the direction of the straight groove extension (X-axis direction). When the thickness of the cutting edge of the cutting tool 16 is set to W, the indexing feed amount is preferably 0.8W to 0.9W. Furthermore, by repeatedly forming the straight groove and indexing, the unprocessed area 48 is formed to the same depth as the annular recess 46. Thus, as... Figure 6 As shown, a standard wafer-compatible tray 2' can be manufactured by forming a circular recess 50 with a diameter (outer diameter) corresponding to the diameter D2 of the wafer 4 to be housed on the upper surface of the plate 2.

[0041] As described above, the standard chip corresponds to tray 2'. Figure 7 As shown, the wafer 4 can be housed in the circular recess 50. Therefore, by using the standard wafer corresponding tray 2', even wafers 4 smaller than the standard wafers corresponding to the processing device can be properly processed in the processing device. For example, even if the chuck stage 14 of the dicing device 12 is not suitable for the size of the wafer 4 and cannot attract and hold the wafer 4 by the chuck stage 14, by placing the wafer 4 in the standard wafer corresponding tray 2' manufactured using the method of the illustrated embodiment, the wafer 4 can be attracted and held on the chuck stage 14 by the standard wafer corresponding tray 2', thereby enabling the dicing device 12 to divide the wafer 4 into device chips of individual devices 8.

[0042] Furthermore, when placing the wafer 4 into the circular recess 50 of the standard wafer corresponding tray 2', positioning the recess 10 of the wafer 4 at the center of the straight section 2a of the standard wafer corresponding tray 2' makes it easier to detect the crystal orientation of the wafer 4 in processing devices such as the dicing apparatus 12. Additionally, referring to... Figure 7 (b) can be understood that the depth of the circular recess 50 of the standard wafer corresponding to the tray 2' can be a smaller dimension than the thickness of the wafer 4.

[0043] In the above embodiments, a method for manufacturing a standard wafer-compatible tray for accommodating a wafer 4 with a notch 10 formed on its outer periphery was described. However, in the method for manufacturing a standard wafer-compatible tray of the present invention, a standard wafer-compatible tray capable of accommodating a wafer with an orientation plane showing the crystal orientation of the wafer formed on its outer periphery can also be manufactured. For this example, refer to... Figures 8 to 10 Please provide an explanation.

[0044] exist Figure 10 The image shows a wafer 54 with an orientation plane 52 formed on its outer periphery. The wafer 54 has the orientation plane 52 formed instead of the notch 10, which is consistent with... Figure 1 The chip 4 shown is different, but its structure is the same as that of chip 4, except for this point.

[0045] When manufacturing a standard wafer-compatible tray capable of holding wafer 54, firstly, a plate-shaped object 2 is prepared (preparation process), and then the plate-shaped object 2 is attracted and held on the chuck stage 14 (holding process). Next, in the annular recess machining process, after aligning the straight portion 2a of the plate-shaped object 2 with the X-axis direction, as follows... Figure 8 As shown, the cutting edge of the cutting tool 16, rotating at a predetermined speed in the R1 direction, cuts into the upper surface of the plate 2 to a predetermined depth. While providing cutting water to the cut portion, the chuck table 14 feeds the material in the X-axis direction at a predetermined feed rate, forming a straight groove 56 with a length corresponding to the orientation plane 52 of the wafer 54. Furthermore, the length of the straight groove 56 may be slightly longer than the length of the orientation plane 52.

[0046] Next, as Figure 9 As shown, the cutting edge of the cutting tool 16, which rotates at a predetermined speed in the R1 direction, cuts into the upper surface of the plate 2 to a predetermined depth from one end 56a of the straight groove 56. While providing cutting water to the cut portion, the chuck table 14 rotates in the R2 direction at a predetermined speed, forming a C-shaped groove 58 extending from one end 56a to the other end 56b of the straight groove 56. This allows the formation of an annular groove (a groove that is generally annular) having a straight groove 56 (straight portion) corresponding to the orientation plane 52 of the outer periphery of the wafer 54 and a C-shaped groove 58 (arc-shaped portion) corresponding to the arc-shaped portion of the outer periphery of the wafer 54.

[0047] Furthermore, while the cutting tool 16 is indexed towards the radially inner side of the chuck table 14 via the indexing feed unit, the formation of C-shaped grooves or annular grooves is repeated, thereby forming an annular recess with a diameter (outer diameter) corresponding to the diameter of the wafer 54 on the upper surface of the plate 2.

[0048] After performing the annular recess machining process, similar to the straight groove machining process described above, the cutting edge of the cutting tool 16, rotating at a predetermined speed in the R1 direction, cuts into the outer periphery of the unmachined area to the same depth as the annular recess. While providing cutting fluid to the cut portion, the chuck table 14 is fed in the X-axis direction at a predetermined feed rate to form a straight groove with the same depth as the annular recess. Furthermore, the straight groove formation is repeated while the cutting tool 16 is indexed in a direction perpendicular to the straight groove, thereby forming the unmachined area to the same depth as the annular recess. Thus, as... Figure 10 As shown, a standard wafer-compatible tray 2 can be manufactured with a recess 60 having a shape corresponding to that of a wafer 54 having an orientation plane 52 formed on its outer periphery.

Claims

1. A method for manufacturing a standard wafer corresponding tray, wherein the standard wafer corresponding tray holds wafers smaller than the standard wafers corresponding to the processing device, wherein, The manufacturing method for the tray corresponding to this standard wafer includes the following steps: Preparation process: Prepare a plate-shaped object with the same shape as a standard wafer; The holding process involves holding the plate-shaped object on a chuck table that can rotate and move linearly. In the annular recess machining process, a rotating cutting tool is positioned on the upper surface of a plate-like object and cuts to a predetermined depth. The chuck table is rotated to form an annular groove. The cutting tool is then sequentially indexed and fed radially along the chuck table to form an annular recess with an outer diameter corresponding to the diameter of the wafer to be housed. In the linear groove machining process, the cutting tool is positioned on the unprocessed area inside the annular recess of the plate and cuts into it to the same depth as the annular recess. The chuck table is moved linearly to form a linear groove. The cutting tool is then indexed and fed sequentially to form the linear groove, thus forming the unprocessed area to the same depth as the annular recess.

2. The method for manufacturing a standard wafer corresponding tray according to claim 1, wherein, When the thickness of the cutting edge of the cutting tool is set to W, the indexing feed rate is 0.8W to 0.9W.

3. The method for manufacturing a standard wafer corresponding tray according to claim 1 or 2, wherein, The thickness of the cutting edge of the cutting tool is 0.5mm to 1.5mm.

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