Chip manufacturing method

Abstract

[Problem] To suppress the increase in manufacturing cost and the extension of time required for wafer manufacturing in a cutting apparatus. [Solution] Before dicing a workpiece to manufacture multiple wafers, a groove is formed in the area where the perforated plate is to overlap with the predetermined dicing lines of the workpiece, and the inner surface of this groove is sealed. In this case, corresponding grooves can be easily formed on the holding surface, and the arrangement of the predetermined dicing lines already set in the workpiece can be easily achieved. As a result, the increase in manufacturing cost and the extension of time required for wafer manufacturing in a cutting apparatus equipped with a work chuck, wherein the work chuck includes a perforated plate having this holding surface, can be suppressed.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a plurality of wafers by dividing a workpiece along a predetermined dividing line. Prior Technology

[0002] The workpiece, such as a packaging substrate, is divided into a plurality of regions by predetermined dividing lines (cutting tracks) arranged in a grid pattern, and a semiconductor device is formed in each of the plurality of regions. Furthermore, by dividing such the workpiece along the predetermined dividing lines, a plurality of wafers, each containing a semiconductor device, can be manufactured.

[0003] In the slicing of such packaged substrates, a cutting device can be used, for example, comprising a worktable that holds the workpiece by applying an attractive force to the workpiece placed on a holding surface, and a cutting unit having a spindle, wherein a circular cutting blade is mounted at the front end of the spindle. In this cutting device, the workpiece is sliced ​​into a plurality of wafers by rotating the cutting blade while the cutting blade contacts the workpiece along a predetermined slicing line.

[0004] However, in order to divide the workpiece into multiple wafers, the rotating cutting blade must penetrate the workpiece. Furthermore, in this case, there is a concern that the worktable holding the workpiece may be damaged by the cutting blade.

[0005] Therefore, when dividing a workpiece into multiple wafers in this way, a cutting tape is usually attached to the workpiece, and the workpiece is held in the work jig through this cutting tape. This allows the workpiece to be divided into multiple wafers with the outer periphery of the cutting blade penetrating the workpiece positioned inside the cutting tape. As a result, damage to the work jig is prevented.

[0006] Furthermore, in this case, there will be no splitting of the cutting tape. And even after the workpiece has been divided into multiple wafers, the wafers can still be integrated using the cutting tape. Therefore, the probability of wafers scattering can be reduced when the workpiece is divided into multiple wafers.

[0007] Cutting tapes like these are consumables. Therefore, if wafers are manufactured using this method, there are concerns that the manufacturing cost of wafers will increase. In view of this, the following approach has also been proposed: while the workpiece is held on a work jig that includes a fixture with a holding surface that directly holds the workpiece, the workpiece is divided into a plurality of wafers (see, for example, Patent Document 1).

[0008] Specifically, a groove (cutting blade retraction groove) is formed in the area corresponding to the predetermined dividing line of the workpiece on the holding surface of this fixture. Furthermore, each of the plurality of areas (wafer corresponding areas) divided by this groove has a through hole (jet hole) for applying attractive force to each of the workpiece and the plurality of wafers.

[0009] Furthermore, when the cutting device is equipped with such a work chuck, the workpiece can be divided into multiple wafers while the outer periphery of the cutting blade penetrating the workpiece is positioned within the internal space of the groove. Also, in this case, since the workpiece can be divided into multiple wafers while the suction force acts on it through the through-hole, the probability of some wafers scattering during this division can be reduced. Previous technical documents Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2007-273546 Summary of the Invention

[0011] The problem the invention aims to solve

[0012] The work jig containing the above-mentioned fixture is a special part that can only be used on specific workpieces. That is, if the arrangement of the predetermined dividing lines set in the workpiece does not correspond to the arrangement of the grooves formed in the fixture, the work jig containing the fixture cannot be used on the dividing of the workpiece.

[0013] Therefore, when the cutting device has a worktable containing jigs, it is necessary to prepare in advance a number of jigs corresponding to different configurations of the predetermined dividing lines and the types of workpieces being processed. This raises concerns that the manufacturing cost of wafers produced using this cutting device may increase, and / or that the time required for wafer manufacturing may lengthen.

[0014] In view of the above, the object of the present invention is to suppress the increase in manufacturing cost of wafers manufactured in the cutting device and the extension of time required for wafer manufacturing. The means to solve the problem

[0015] According to the present invention, a method for manufacturing a wafer is provided, wherein a plurality of wafers are manufactured by slicing the workpiece along a predetermined slitting line in a cutting apparatus. The cutting apparatus comprises: a work chuck including a perforated plate and a frame; the perforated plate being made of a first synthetic resin and having a holding surface for holding the workpiece; the frame being made of a second synthetic resin and surrounding the perforated plate with the holding surface of the perforated plate exposed; and a cutting unit having a spindle with an annular cutting blade mounted at its front end. The wafer manufacturing method comprises the following steps: In the groove forming step, while rotating the first cutting blade, the first cutting blade is brought into contact with the porous plate along the area where it is to be pre-intersected with the pre-defined dividing line, thereby forming a groove on the retaining surface; In the coating step, after the groove forming step, a resin that seals the inner surface of the groove is applied to the retaining surface; The workpiece holding step, after the coating step, holds the workpiece on the holding surface; and In the slicing step, after the workpiece holding step, a second cutting blade with a narrower blade width than the first cutting blade is rotated and brought into contact with the workpiece along the predetermined slicing line, thereby slicing the workpiece into the plurality of wafers.

[0016] Preferably, the present invention further includes the following steps: A workpiece holding step for trench forming, wherein the workpiece for trench forming is held on the holding surface prior to the trench forming step; and The removal step involves removing the groove-forming workpiece from the holding surface after the coating step and before the workpiece holding step. In the groove forming step, a groove is formed on the holding surface that extends through the groove forming workpiece and reaches the perforated plate. In the coating step, the groove forming workpiece functions as a mask to prevent resin from being coated on the area of ​​the holding surface other than the area where the groove is formed.

[0017] Alternatively, the present invention further includes a removal step, wherein the aforementioned removal step is performed after the coating step and before the workpiece holding step, to remove the resin from the area outside the region where the groove is formed on the holding surface. Invention Effects

[0018] In this invention, before slicing a workpiece to manufacture a plurality of wafers, a groove is formed in a region where the perforated plate is to overlap with a predetermined slicing line on the workpiece, and the inner surface of this groove is sealed. Therefore, in this invention, a work stand comprising a perforated plate can be formed, the perforated plate having holding surfaces for both the workpiece and the plurality of wafers manufactured by slicing the workpiece.

[0019] Specifically, when the workpiece is divided in this holding surface, the attractive force can act on the holding surface side through the area outside the grooved region of the perforated plate. Furthermore, because the inner surface of this groove is sealed, there will be no attractive force acting on the holding surface side through the grooved region of the perforated plate. That is, there will be no leakage when holding the workpiece or multiple wafers on this holding surface.

[0020] In this way, in the present invention, corresponding grooves such as those formed on the holding surface and the arrangement of predetermined dividing lines already set in the workpiece can be easily achieved. As a result, the increase in manufacturing cost and the extension of time required for wafer manufacturing in a cutting apparatus equipped with a work chuck can be suppressed, wherein the aforementioned work chuck includes a perforated plate having this holding surface. Simple Explanation of the Diagram

[0021] Figure 1 is a perspective view schematically showing one example of a cutting device. Figure 2 is an exploded perspective view schematically showing one example of a workbench base and one example of a work clamp. Figure 3 is a perspective view schematically showing one example of a workpiece. Figure 4 is a flowchart schematically illustrating one example of a chip manufacturing method. Figure 5(A) is a partial cross-sectional side view schematically showing the workpiece holding step for groove formation, Figure 5(B) is a partial cross-sectional side view schematically showing the groove formation step, and Figure 5(C) is a partial cross-sectional side view schematically showing the work stand and the like after the coating step. Figure 6(A) is a partial cross-sectional side view schematically showing the work chuck and the like after the removal step; Figure 6(B) is a partial cross-sectional side view schematically showing the workpiece holding step; and Figure 6(C) is a partial cross-sectional side view schematically showing the splitting step. Figure 7 is a flowchart schematically showing a variation of a wafer manufacturing method. Figure 8(A) is a partial cross-sectional side view schematically showing the groove formation step, and Figure 8(B) is a partial cross-sectional side view schematically showing the work stand and the like after the coating step. Figure 9 is a partial cross-sectional side view schematically showing the removal step. Implementation

[0022] Forms used to implement inventions

[0023] Referring to the accompanying drawings, embodiments of the present invention will be described. FIG1 is a perspective view schematically showing an example of a cutting apparatus used to slit a workpiece to manufacture a plurality of wafers. Furthermore, the X-axis direction (front-back direction) and the Y-axis direction (left-right direction) shown in FIG1 are mutually perpendicular directions on a horizontal plane, and the Z-axis direction (up-down direction) is a direction perpendicular to the X-axis direction and the Y-axis direction (vertical direction).

[0024] The cutting device 2 shown in Figure 1 has a base 4 that supports a plurality of components. An opening 4a extending along the X-axis is formed on the upper surface of the base 4. An X-axis moving worktable (not shown) and a worktable moving mechanism 6 for moving the X-axis moving worktable along the X-axis are arranged inside the opening 4a.

[0025] The table moving mechanism 6 includes, for example, a ball screw. Furthermore, the upper side of the X-axis moving table and the table moving mechanism 6 is covered by a table cover 8 and a basalt-shaped cover 10. Also, on the X-axis moving table, a rectangular table base 12 is arranged to protrude upwards from the table cover 8.

[0026] The worktable base 12 is connected to a rotary drive source (not shown), such as a motor, and rotates along a straight line parallel to the Z-axis. Furthermore, the worktable base 12 and the aforementioned X-axis moving worktable move together along the X-axis. Additionally, a work clamp 14 for holding a rectangular workpiece is detachably mounted on the upper part of the worktable base 12.

[0027] Figure 2 is an exploded perspective view schematically showing the worktable base 12 and the work clamp 14. The worktable base 12 has a parallel upper surface 12a and a lower surface 12b, and a cuboid recess 12c is formed on the side of the upper surface 12a. Furthermore, a cylindrical through hole 12d is formed in the center of the worktable base 12, and this through hole 12d opens on the bottom surface of the recess 12c and the lower surface 12b.

[0028] Furthermore, this through hole 12d is connected to an attraction source such as an injector. Additionally, an inner wall 12e is provided on the bottom surface of the recess 12c, surrounding the through hole 12d, and its upper surface is lower than the upper surface 12a. Also, near each of the four corners of the worktable base 12, a cylindrical groove 12f opening onto the upper surface 12a is formed. Furthermore, a spiral groove (thread groove) is formed on the side of this groove 12f.

[0029] The worktable 14 mounted on the worktable base 12 has a rectangular frame 16. This frame 16 is made of a synthetic resin such as polyurethane (a second synthetic resin) and has an upper surface 16a and a lower surface 16b that are parallel to each other. Furthermore, a rectangular recess is formed on the upper surface 16a side of the frame 16, defined by the bottom wall and side walls of the frame 16.

[0030] A rectangular perforated plate 18 is fixed to a recess formed on the upper surface 16a side of the frame 16. That is, the perforated plate 18 is surrounded by the sidewall of the frame 16, and its lower surface (not shown in Figure 2) faces the bottom wall of the frame 16. Furthermore, the upper surface (holding surface) 18a of the perforated plate 18 is exposed on the same plane as the upper surface 16a of the frame 16.

[0031] Furthermore, the porous plate 18 is formed of a porous synthetic resin (first synthetic resin) such as foamed polyurethane. Moreover, the synthetic resin constituting the frame 16 and the porous synthetic resin constituting the porous plate 18 may be the same material or different materials.

[0032] Furthermore, a cylindrical through hole (not shown) is formed in the center of the frame 16, opening on the bottom surface of the recess and the lower surface 16b of the frame 16. Therefore, the recess 12c and the through hole 12d of the workbench base 12 are interconnected with the lower surface of the perforated plate 18 through the through hole formed in the center of the frame 16.

[0033] Furthermore, the upper surface 16a of the frame 16 has a shape almost identical to the upper surface 12a of the worktable base 12. Also, the lower surface 16b of the frame 16 has a shape almost identical to the lower surface 12b of the worktable base 12. In addition, near each of the four corners of the frame 16, a cylindrical through hole 16c opening onto both the upper surface 16a and the lower surface 16b is formed.

[0034] Furthermore, a spiral groove (thread groove) can also be formed on the side of this through hole 16c. Also, this through hole 16c is configured to overlap with the groove 12f formed on the worktable base 12 when the worktable base 12 and the work clamp 14 are overlapped so that the side of the worktable base 12 and the side of the work clamp 14 (the outer side of the frame 16) are flush.

[0035] Then, with the worktable base 12 and the work clamp 14 already overlapped, the bolts 20 are inserted into the through hole 16c and the groove 12f to lock them in place, thus fixing the frame 16 to the worktable base 12. That is, the work clamp 14 with the frame 16 can be installed on the worktable base 12 by tightening the bolts 20 in this way.

[0036] Furthermore, when the suction source connected to the through hole 12d is activated with the work chuck 14 already mounted on the worktable base 12, the suction force acts on the holding surface 18a of the perforated plate 18 through the through hole 12d, the recess 12c, and the perforated plate 18. This allows the workpiece to be held on the holding surface 18a of the perforated plate 18. Moreover, in the cutting apparatus 2, the workpiece held on the holding surface 18a can be divided to manufacture a plurality of wafers.

[0037] Figure 3 is a perspective view schematically showing an example of a workpiece being divided in the cutting device 2. This workpiece 11 is, for example, a packaging substrate that can be obtained by sealing a plurality of devices with resin. The workpiece 11 shown in Figure 3 includes a cuboid substrate 13, which has a front side that is slightly wider than the holding surface 18a of the perforated plate 18.

[0038] The substrate 13 is made of a metallic material such as alloy 42 (an alloy of iron and nickel) or copper, and includes a plurality of device regions 15 (here, 3 device regions 15) and a remaining region 17 surrounding each of the plurality of device regions 15. Furthermore, each of the plurality of device regions 15 is divided into a plurality of regions (here, 16 regions) by predefined dividing lines 19 arranged in a grid pattern.

[0039] Furthermore, on the front side 11a of the workpiece 11, a plurality of platforms 21 are exposed, which are demarcated by the dividing pre-line 19. Around each of the plurality of platforms 21 (in the area overlapping with the dividing pre-line 19), a plurality of metal layers (not shown) are disposed, for example, insulated from each other by resin or the like.

[0040] Semiconductor devices such as ICs (Integrated Circuits), LEDs (Light Emitting Diodes), or MEMS (Micro Electro Mechanical Systems) are assembled on the back side of each of the plurality of stages 21.

[0041] Furthermore, the electrodes of this semiconductor device are connected to the metal layer disposed around the stage 21 by means of metal wires (not shown). Also, a portion of this metal layer becomes an electrode for each of the plurality of wafers obtained by dividing the workpiece 11.

[0042] Referring again to Figure 1, the remaining components of the cutting device 2 will be described. A gate-shaped support structure 22 is arranged on the upper surface of the base 4, spanning the opening 4a. A pair of cutting unit moving mechanisms 24 are provided on the front side of the support structure 22. The pair of cutting unit moving mechanisms 24 share a pair of Y-axis guide rails 26 arranged on the upper part of the front surface of the support structure 22 and extending along the Y-axis direction.

[0043] On this Y-axis guide rail 26, a Y-axis moving plate 28, which is included in each of a pair of cutting unit moving mechanisms 24, is mounted in a manner that allows it to slide along the Y-axis direction. A nut portion (not shown) containing a ball screw is fixed to the back (rear surface) side of this Y-axis moving plate 28. A screw shaft 30 extending along the Y-axis direction is rotatably connected to this nut portion.

[0044] Furthermore, a Y-axis pulse motor 32 is connected to one end of the screw shaft 30. By rotating the screw shaft 30 using the Y-axis pulse motor 32, the Y-axis moving plate 28 moves along the Y-axis direction. Additionally, a pair of Z-axis guide rails 34 extending along the Z-axis direction are arranged on the front surface (front surface) of the Y-axis moving plate 28.

[0045] On this Z-axis guide rail 34, a Z-axis movable plate 36 is mounted so as to be able to slide along the Z-axis direction. Furthermore, a nut portion (not shown) containing a ball screw is fixed to the back (rear surface) side of the Z-axis movable plate 36. A screw shaft 38 extending along the Z-axis direction is rotatably connected to this nut portion.

[0046] Furthermore, a Z-axis pulse motor 40 is connected to one end of the screw shaft 38. By rotating the screw shaft 38 using the Z-axis pulse motor 40, the Z-axis moving plate 36 moves along the Z-axis direction. A cutting unit 42 is provided at the lower part of the Z-axis moving plate 36.

[0047] This cutting unit 42 has, for example, a cylindrical spindle housing, in which a spindle extending along the Y-axis and a rotational drive source such as a motor connected to the base end of the spindle are housed. Furthermore, the tip end of the spindle protrudes from the spindle housing.

[0048] A circular cutting blade 44 is mounted on the front end of the spindle, which protrudes from the spindle housing, via a blade mounting seat. Furthermore, if the rotation drive source connected to the base end of this spindle is activated, the cutting blade 44 rotates together with the spindle along a straight line in the Y-axis direction.

[0049] This cutting insert 44 can be, for example, a hub-type cutting insert, which is constructed by integrally forming a ring-shaped base made of metal or the like with a ring-shaped cutting edge along the outer periphery of the base. The cutting edge of the hub-type cutting insert can be obtained by fixing abrasive grains made of diamond or cubic boron nitride (cBN) with a binder material such as nickel.

[0050] Furthermore, as a cutting insert 44, a washer-type cutting insert consisting solely of annular cutting edges can also be used. The washer-type cutting insert (cutting edge) is obtained by fixing abrasive grains made of diamond or cBN using a binder such as resin.

[0051] Furthermore, an imaging unit 46 is fixed at the lower part of the Z-axis moving plate 36. The imaging unit 46 is positioned adjacent to the cutting unit 42 in the X-axis direction. The imaging unit 46 includes a two-dimensional light sensor, such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor that is sensitive to visible light, and an imaging lens.

[0052] Furthermore, as long as the Y-axis moving plate 28 of the cutting unit moving mechanism 24 moves along the Y-axis direction, the cutting unit 42 and the imaging unit 46 will move together along the Y-axis direction. Also, as long as the Z-axis moving plate 36 of the cutting unit moving mechanism 24 moves along the Z-axis direction, the cutting unit 42 and the imaging unit 46 will move together along the Z-axis direction.

[0053] Figure 4 is a flowchart schematically showing an example of a wafer manufacturing method that divides the workpiece 11 along a predetermined dividing line 19 to manufacture a plurality of wafers. Figures 5(A), 5(B), 5(C), 6(A), 6(B), and 6(C) are partial cross-sectional side views schematically showing the various steps included in this method.

[0054] In this method, the groove forming workpiece is first held on the holding surface 18a of the perforated plate 18 (groove forming workpiece holding step: S1). Figure 5(A) is a partial cross-sectional side view schematically showing the groove forming workpiece holding step (S1).

[0055] Furthermore, the groove-forming workpiece 23 has the same rectangular shape as the workpiece 11. Also, the groove-forming workpiece 23 is made of, for example, the same synthetic resin as the material used for the porous plate 18 (e.g., polyurethane). Alternatively, the groove-forming workpiece 23 may also be a protective tape made of polyolefin or the like.

[0056] In this groove-forming workpiece holding step (S1), the groove-forming workpiece 23 is placed on the worktable 14 such that the center of the holding surface 18a of the perforated plate 18 is aligned with the center of one side 23a of the groove-forming workpiece 23. Then, the suction source communicating with the through hole 12d of the worktable base 12 is activated.

[0057] In this way, the attractive force acts on the holding surface 18a side of the perforated plate 18 through the through hole 12d and the recess 12c of the worktable base 12 and the perforated plate 18. As a result, the workpiece 23 can be held in the groove formed on the holding surface 18a of the perforated plate 18.

[0058] Furthermore, if the groove forming workpiece 23 is a protective tape, it can be attached to the holding surface 18a of the perforated plate 18. Therefore, in this case, it is preferable that the suction source does not need to be activated as described above. Also, in this case, it is preferable that the groove forming workpiece 23 will not be unable to be held due to leakage through the gap between the groove forming workpiece 23 and the holding surface 18a.

[0059] Next, along the area where the pre-determined dividing line 19 of the perforated plate 18 overlaps with that of the workpiece 11, a through-groove forming workpiece 23 is formed and reaches the groove of the perforated plate 18 (groove forming step: S2). Figure 5(B) is a partial cross-sectional side view schematically showing the situation of the groove forming step (S2). Furthermore, before the groove forming step (S2), a groove forming cutting insert (first cutting insert) 44a is installed at the front end of the spindle 48 of the cutting unit 42.

[0060] In this groove forming step (S2), the work chuck 14 is first rotated so that the portion of the perforated plate 18 that extends linearly in the area where it is to overlap with the predetermined dividing line 19 of the workpiece 11 becomes parallel to the X-axis direction. Then, the work chuck 14 and / or the cutting unit 42 are moved so that, viewed from the groove forming cutting insert 44a in a planar view, this portion is positioned in the X-axis direction.

[0061] Next, the cutting unit 42 is lowered to position the lower end of the groove forming cutting blade 44a at a position lower than the holding surface 18a of the perforated plate 18 and higher than its lower surface 18b. Then, the worktable 14 is moved such that the groove forming cutting blade 44a is rotated through the spindle 48, and the groove forming workpiece 23 is in contact with the groove forming cutting blade 44a from one end to the other in the X-axis direction of the frame 16 and the perforated plate 18.

[0062] In this way, the groove forming workpiece 23 and the perforated plate 18 are cut to form a straight groove 25 that runs through the groove forming workpiece 23 and reaches the perforated plate 18. Then, the same operation is repeated to form the groove 25 in the entire area of ​​the perforated plate 18 that is to overlap with the predetermined dividing line 19 of the workpiece 11.

[0063] Next, a resin is applied to the retaining surface 18a to seal the inner surface of the groove 25 formed on the retaining surface 18a of the porous plate 18 (coating step: S3). Figure 5(C) is a partial cross-sectional side view schematically showing the work stand 14, etc., after the coating step (S3). Furthermore, the resin used in the coating step (S3) can be, for example, thermosetting resins such as polyurethane, epoxy resin, or melamine resin, or thermoplastic resins such as polypropylene or polyethylene.

[0064] In this coating step (S3), resin is applied to the groove 25 using, for example, a conventional spray gun. Alternatively, resin can be applied to the area near the groove 25 of the groove-forming workpiece 23. This forms a resin film 27 covering the inner surface of the groove 25 and the area near the groove 25 of the groove-forming workpiece 23.

[0065] This resin film 27 seals the inner surface of the groove 25. Furthermore, the groove-forming workpiece 23 functions as a shield to prevent resin from being applied to areas of the retaining surface 18a of the porous plate 18 other than the area where the groove 25 is formed (the area overlapping with the groove-forming workpiece 23). Therefore, the area of ​​the retaining surface 18a of the porous plate 18 that overlaps with the groove-forming workpiece 23 is not sealed.

[0066] Next, the groove forming workpiece 23 is removed from the holding surface 18a of the perforated plate 18 (removal step: S4). Figure 6(A) is a partial cross-sectional side view schematically showing the work stand 14 and the like after the removal step (S4).

[0067] When the groove-forming workpiece 23 has been attracted and held, in this removal step (S4), the groove-forming workpiece 23 is removed from the work chuck 14 after the operation of the attraction source communicating with the through hole 12d of the worktable base 12 has stopped. Furthermore, if the groove-forming workpiece 23 is a protective tape, in this removal step (S4), an external force is applied to separate the groove-forming workpiece 23 from the holding surface 18a.

[0068] Next, the workpiece 11 is held on the holding surface 18a of the perforated plate 18 (workpiece holding step: S5). Figure 6(B) is a partial cross-sectional side view schematically showing the workpiece holding step (S5).

[0069] In this workpiece holding step (S5), the workpiece 11 is placed on the work jig 14 in such a way that the center of the holding surface 18a of the perforated plate 18 is aligned with the center of the back surface 11b of the workpiece 11. Then, the suction source communicating with the through hole 12d of the worktable base 12 is activated.

[0070] In this way, the attractive force acts on the holding surface 18a side through the through hole 12d and the recess 12c of the worktable base 12 and the perforated plate 18, and through the area of ​​the perforated plate 18 other than the area where the groove 25 is formed. Furthermore, because the inner surface of this groove 25 is sealed, there is no leakage through this groove 25. As a result, the workpiece 11 can be held on the holding surface 18a of the perforated plate 18.

[0071] Next, the workpiece 11 is divided into a plurality of wafers (division step: S6). Figure 6(C) is a partial cross-sectional side view schematically showing the division step (S6). Furthermore, prior to the division step (S6), a workpiece cutting blade (second cutting blade) 44b with a narrower cutting edge width than the groove forming cutting blade 44a is installed at the front end of the spindle 48 of the cutting unit 42.

[0072] In this segmentation step (S6), the work chuck 14 is first rotated so that the portion of the workpiece 11 that extends linearly along the predetermined segmentation line 19 becomes parallel to the X-axis direction. Then, the work chuck 14 and / or the cutting unit 42 are moved so that, from a planar perspective, this portion is positioned in the X-axis direction when viewed from the workpiece using the cutting insert 44b.

[0073] Next, the cutting unit 42 is lowered so that the lower end of the workpiece using the cutting insert 44b is positioned lower than the back surface 11b of the workpiece 11 and higher than the bottom surface of the groove 25. Then, the worktable 14 is moved in such a way that the workpiece 11 is in contact with the workpiece cutting insert 44b from one end to the other in the X-axis direction while the workpiece cutting insert 44b is rotated through the spindle 48.

[0074] In this way, the workpiece 11 is cut and divided along the predetermined dividing line 19. At this time, although the area of ​​the porous plate 18 with the groove 25 is exposed, there is no leakage through the groove 25 because the inner surface of the groove 25 is sealed. Then, the same operation is repeated to divide the workpiece 11 into a plurality of wafers along the predetermined dividing line 19.

[0075] In the method shown in Figure 4, before slicing the workpiece 11 to manufacture a plurality of wafers, a groove 25 is formed in the area where the perforated plate 18 is to overlap with the predetermined slicing line 19 of the workpiece 11, and the inner surface of this groove 25 is sealed. Therefore, in this method, a work chuck 14 including the perforated plate 18 can be formed, and the perforated plate 18 has a holding surface 18a that can hold both the workpiece 11 and the plurality of wafers manufactured by slicing the workpiece 11.

[0076] Specifically, when the workpiece 11 is held in a position on the holding surface 18a, the attractive force can act on the holding surface 18a side through the area outside the region where the groove 25 is formed in the perforated plate 18. Furthermore, because the inner surface of the groove 25 is sealed, there will be no attractive force acting on the holding surface 18a side through the region where the groove 25 is formed in the perforated plate 18. That is, there will be no leakage when the workpiece 11 or multiple wafers are held on the holding surface 18a.

[0077] In this way, corresponding grooves 25 can be easily formed on the holding surface 18a and arranged in accordance with the configuration of the pre-defined dividing lines 19 already set in the workpiece 11. As a result, the increase in manufacturing cost of wafers manufactured in the cutting apparatus 2 equipped with the work chuck 14 and the extension of the time required for wafer manufacturing can be suppressed, wherein the aforementioned work chuck 14 includes a perforated plate 18 having this holding surface 18a.

[0078] Furthermore, the above-described method is one aspect of the present invention, and the present invention is not limited to the above-described method. For example, in the coating step (S3) of the present invention, the resin can also be coated in such a way that the portion of the groove 25 located below the groove-forming workpiece 23 is filled with resin. Also, in this case, in the cutting step (S6), the resin filled in the groove 25 can also be cut together with the workpiece 11.

[0079] Furthermore, in this invention, the trench forming workpiece 23 may not be used. Figure 7 is a flowchart schematically showing an example of a method for manufacturing such a wafer. Also, Figures 8(A), 8(B), and 9 are partial cross-sectional side views schematically showing the various steps included in this method.

[0080] In this method, firstly, a groove is formed on the holding surface 18a of the perforated plate 18 along the area where it is to overlap with the predetermined dividing line 19 of the workpiece 11 (groove forming step: S10). Figure 8(A) is a partial cross-sectional side view schematically showing the groove forming step (S10). Furthermore, before the groove forming step (S10), a groove forming cutting insert (first cutting insert) 44a is mounted on the front end of the spindle 48 of the cutting unit 42.

[0081] In this groove forming step (S10), the work chuck 14 is rotated with the entire area of ​​the holding surface 18a of the perforated plate 18 exposed, so that the portion of the perforated plate 18 that is destined to overlap with the predetermined dividing line 19 of the workpiece 11, extending in a straight line, becomes parallel to the X-axis direction. Then, the work chuck 14 and / or the cutting unit 42 are moved so that, viewed from the groove forming cutting insert 44a in a planar view, this portion is positioned in the X-axis direction.

[0082] Next, the cutting unit 42 is lowered to position the lower end of the groove-forming cutting blade 44a at a position lower than the holding surface 18a of the perforated plate 18 and higher than its lower surface 18b. Then, the worktable 14 is moved such that the groove-forming cutting blade 44a is rotated through the spindle 48, and the frame 16 and the perforated plate 18 are in contact with the groove-forming cutting blade 44a from one end to the other in the X-axis direction.

[0083] In this way, the perforated plate 18 is cut, and a straight groove 29 is formed on the holding surface 18a. Then, the same operation is repeated, and the groove 29 is formed in the entire area of ​​the perforated plate 18 that is to overlap with the predetermined dividing line 19 of the workpiece 11.

[0084] Next, a resin is applied to the retaining surface 18a to seal the inner surface of the groove 29 formed in the retaining surface 18a of the porous plate 18 (coating step: S20). Figure 8(B) is a partial cross-sectional side view schematically showing the work stand 14, etc., after the coating step (S20). Furthermore, the resin used in the coating step (S20) can be, for example, thermosetting resins such as polyurethane, epoxy resin, or melamine resin, or thermoplastic resins such as polypropylene or polyethylene.

[0085] In this coating step (S20), resin is applied to the groove 29 using, for example, a conventional spray gun. At this time, resin is also applied to the area (peripheral area) of the retaining surface 18a of the porous plate 18 located around the groove 29. This forms a resin film 31 covering the inner surface of the groove 29 and the peripheral area. This resin film 31 seals the inner surface of the groove 29 and the peripheral area.

[0086] Next, the resin coated on the holding surface 18a of the porous plate 18, except for the area where the groove 29 is formed (here, the area surrounding the groove 29), is removed (removal step: S30). This removal step (S30) can be performed, for example, in a conventional grinding apparatus, by grinding the holding surface 18a side of the porous plate 18.

[0087] Figure 9 is a partial cross-sectional side view schematically showing the removal step (S30) performed in a conventional grinding apparatus. Specifically, in this removal step (S30), the work chuck 14 is first removed from the worktable base 12 of the cutting apparatus 2. Next, a back-grinding tape (BG tape) 33 is attached to the lower surface of the work chuck 14 (the lower surface 16b of the frame 16).

[0088] Next, the work chuck 14 is placed on the holding surface 52a of the work chuck 52 of the grinding apparatus 50 via the BG tape 33. This work chuck 52 has, for example, the same structure as the work chuck 14. Furthermore, the work chuck 52 is connected to an attraction source (not shown) that causes the attraction force to act on the holding surface 52a side, and a horizontal movement mechanism that moves the work chuck 52 in the horizontal direction.

[0089] Furthermore, a grinding unit 54 is provided above the worktable 52. This grinding unit 54 is connected to a vertical movement mechanism that moves the grinding unit 54 in the vertical direction. The grinding unit 54 also has a cylindrical spindle 56 extending in the vertical direction.

[0090] A disc-shaped mounting base 58 made of metal or the like is fixed to the front end (lower end) of the spindle 56. Furthermore, a rotary drive source (not shown), such as a motor, is connected to the base end (upper end) of the spindle 56 to rotate the spindle 56. When the rotary drive source connected to the base end of the spindle 56 is activated, the spindle 56 will rotate about a straight line approximately parallel to the vertical direction as its axis of rotation.

[0091] Furthermore, a circular grinding wheel 60 is mounted on the lower surface of the mounting base 58. This grinding wheel 60 is fixed to the mounting base 58 using a fastener (not shown) such as a bolt. Thus, the grinding wheel 60 is mounted on the front end of the spindle 56 via the mounting base 58. And, when the spindle 56 rotates, the grinding wheel 60 mounted on the front end also rotates about a straight line approximately parallel to the vertical direction as its axis of rotation.

[0092] Furthermore, the grinding wheel 60 has a wheel base 62 and a plurality of grinding stones 64 fixed to the lower surface of the wheel base 62. The wheel base 62 has an annular shape with an outer diameter approximately equal to the diameter of the mounting base 58, and can be made of metal such as stainless steel or aluminum, or resin.

[0093] Furthermore, the plurality of grinding stones 64 are arranged discretely relative to each other along the circumference of the grinding wheel 60 (wheel base 62). Each of the plurality of grinding stones 64 has a cuboid shape and includes abrasive grains made of, for example, diamond or cBN (cubic boron nitride) and a bonding material (adhesive) that holds these abrasive grains in place. Moreover, this bonding material can be, for example, a metal bond, a resin bond, or a ceramic bond (vitrified bond).

[0094] By simply placing the work chuck 14 onto the holding surface 52a of the work chuck 52 via the BG tape 33, the suction source already connected to the work chuck 52 can be activated. This allows the work chuck 14 to be held on the holding surface 52a. Next, the work chuck 52 is moved to position the paths of the plurality of grinding stones 64 that cause the spindle 56 to rotate directly above the center of the work chuck 14.

[0095] Next, while rotating both the work chuck 52 and the grinding wheel 60, the grinding unit 54 is lowered until the lower surface of each of the plurality of grinding stones 64 contacts the resin film 31 already set on the work chuck 14. In this way, a portion of the resin film 31 is ground away and removed. Then, the work chuck 52 and the grinding wheel 60 continue to rotate, and the grinding unit 54 is lowered until a portion of the area surrounding the covering groove 29 of the resin film 31 is completely removed.

[0096] Once the periphery of the covering groove 29 of the resin film 31 has been completely removed, the work chuck 52 can be separated from the grinding wheel 60, and the operation of the suction source connected to the work chuck 52 can be stopped. Next, the work chuck 14 and the BG tape 33 are removed together from the work chuck 52 of the grinding device 50. Then, the BG tape 33 is peeled off from the lower surface of the work chuck 14 (the lower surface 16b of the frame 16).

[0097] Next, the worktable 14 is mounted again onto the worktable base 12 of the cutting device 2. Then, after holding the workpiece 11 on the holding surface 18a of the perforated plate 18 (workpiece holding step: S40), the workpiece 11 is divided into a plurality of wafers (division step: S50). Furthermore, since the workpiece holding step (S40) and the division step (S50) correspond to the workpiece holding step (S5) and the division step (S6) shown in FIG4, respectively, detailed descriptions of them are omitted.

[0098] Furthermore, in the wafer manufacturing method shown in FIG7, after coating the entire area of ​​the holding surface 18a of the porous plate 18 with resin in the coating step (S20), the resin in the area outside the area where the groove 29 is formed on the holding surface 18a can be removed in the removal step (S30).

[0099] Furthermore, the structure and method of the above-described embodiments can be appropriately modified and implemented as long as they do not depart from the purpose of this invention.

[0100] 2: Cutting device 4:Abutment 4a: Opening 6: Workbench moving mechanism 8: Workbench cover 10: Belly-shaped cover 11: Workpiece 11a: Front 11b: Back 12: Workbench base 12a, 16a: Upper surface 12b, 16b, 18b: Lower surface 12c: concave part 12d, 16c: Through holes 12e: Inner wall 12f,25,29: Ditch 13:Substrate 14,52: Worktable 15: Device Area 16: Frame 17: Remaining Area 18: Perforated Plate 18a: Top surface (retaining surface) 19: Pre-defined dividing line 20: Bolts 21: Platform 22: Support Structure 23: Workpiece for trench forming 23a: One side 24: Cutting unit moving mechanism 26: Y-axis guide rail 27,31: Resin film 28: Y-axis moving plate 30, 38: Screw shaft 32: Y-axis pulse motor 33: Crystal Back Grinding Tape (BG Tape) 34: Z-axis guide rail 36: Z-axis moving plate 40: Z-axis pulse motor 42: Cutting Unit 44: Cutting inserts 44a: Groove forming cutting insert (first cutting insert) 44b: Cutting insert for the workpiece (second cutting insert) 46: Filming Unit 48, 56: Spindle 50: Grinding device 52a: Maintain surface 54: Grinding Unit 58: Mounting bracket 60: Grinding wheel 62: Wheel base platform 64: Grinding stone S1: Workpiece holding step for trench forming S2, S10: Trench Formation Steps S3, S20: Coating steps S4: Remove steps S5, S40: Workpiece holding steps S6, S50: Segmentation steps S30: Removal Steps X, Y, Z: Direction

Claims

1. A method for manufacturing a wafer, wherein a plurality of wafers are manufactured by slicing a workpiece along a predetermined slitting line in a cutting apparatus, the cutting apparatus comprising: a work chuck comprising a perforated plate and a frame, the perforated plate being made of a first synthetic resin and having a holding surface for holding the workpiece, the frame being made of a second synthetic resin and surrounding the perforated plate in a manner in which the holding surface of the perforated plate is exposed; and a cutting unit having a spindle having an annular cutting blade mounted at its front end, the method for manufacturing the wafer comprising the following steps: a workpiece holding step for groove forming, wherein a workpiece for groove forming is held on the holding surface of the perforated plate contained in the work chuck containing the frame; a groove forming step, wherein after the workpiece holding step for groove forming, a first cutting blade is rotated and, along a region of the perforated plate that is predetermined to overlap with the predetermined slitting line, the first cutting blade contacts the perforated plate, thereby forming a groove on the holding surface; and a coating step, wherein after the groove forming step, a resin for sealing the inner surface of the groove is coated onto the holding surface. The process includes a removal step, where the trench-forming workpiece is removed from the holding surface after the coating step; a workpiece holding step, where the workpiece is held on the holding surface after the removal step; and a dividing step, where, after the workpiece holding step, a second cutting blade with a narrower cutting edge than the first cutting blade is rotated and brought into contact with the workpiece along the predetermined dividing line, thereby dividing the workpiece into the plurality of wafers. In the trench-forming step, a trench is formed on the holding surface that penetrates the trench-forming workpiece and reaches the porous plate. In the coating step, the trench-forming workpiece functions as a mask to prevent resin from being coated on areas of the holding surface other than the area where the trench is formed. A plurality of through holes are formed on the frame. The cutting device further includes a worktable base, which has a plurality of grooves, and the frame is fixed by inserting a plurality of bolts into the plurality of through holes and the plurality of grooves respectively.

2. A method for manufacturing a wafer, wherein a plurality of wafers are manufactured by slicing a workpiece along a predetermined slitting line in a cutting apparatus, the cutting apparatus comprising: a work chuck comprising a perforated plate and a frame, the perforated plate being made of a first synthetic resin and having a holding surface for holding the workpiece, the frame being made of a second synthetic resin and surrounding the perforated plate in a manner in which the holding surface of the perforated plate is exposed; and a cutting unit having a spindle having an annular cutting blade mounted at its front end, the method for manufacturing the wafer comprising the following steps: a groove forming step, wherein while rotating a first cutting blade, the first cutting blade is brought into contact with the perforated plate along a region of the perforated plate that is predetermined to overlap with the predetermined slitting line, thereby forming a groove on the holding surface; a coating step, wherein after the groove forming step, a resin is coated onto the holding surface to seal the inner surface of the groove; and a removal step, wherein after the coating step, the resin coated on the holding surface in areas other than the region where the groove is formed is removed. The workpiece holding step, after the removal step, holds the workpiece on the holding surface; and the dividing step, after the workpiece holding step, rotates a second cutting blade with a blade width narrower than the first cutting blade, and makes the second cutting blade contact the workpiece along the predetermined dividing line, thereby dividing the workpiece into the plurality of wafers.

3. The method for manufacturing a wafer as claimed in claim 2, wherein a plurality of through holes are formed on the frame, and the cutting device further comprises a worktable base, wherein the worktable base is formed with a plurality of grooves, and the frame is fixed by locking a plurality of bolts into the plurality of through holes and the plurality of grooves respectively.

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