Chip manufacturing method

Abstract

To provide a chip manufacturing method capable of suppressing residue of a foreign matter adhered to a protective tape.SOLUTION: A manufacturing method of a chip which divides a workpiece demarcated into a plurality of areas by a division schedule line into a plurality of chips includes: a groove forming step which forms a groove on a surface side of the workpiece along a division schedule line; a protective tape sticking step which pastes the protective tape on the surface side of the workpiece after the groove formation step; a grinding step which divides the workpiece into a plurality of chips by grinding a reverse surface side of the workpiece and exposing the groove after the protective tape sticking step; and a washing step for washing the workpiece by supplying washing liquid for the reverse surface side of the workpiece from a nozzle moving in an area overlapping the workpiece while rotating the workpiece after the grinding step. At the washing step, the nozzle is decelerated when the nozzle approaches an axis of rotation of the workpiece and the nozzle is accelerated when the nozzle moves away from the axis of rotation of the workpiece.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method for manufacturing chips that divide a workpiece into a plurality of chips.

Background Art

[0002] In the manufacturing process of device chips, a wafer in which devices are formed in a plurality of regions partitioned by a plurality of division planned lines (streets) arranged in a grid pattern is used. By dividing this wafer along the division planned lines, chips (device chips) equipped with devices can be obtained. Device chips are incorporated into various electronic devices such as mobile phones and personal computers.

[0003] In recent years, with the miniaturization of electronic devices, thinning of device chips has been demanded. Therefore, before dividing the wafer, a process of grinding and thinning the wafer may be performed. By dividing the thinned wafer, thin device chips can be obtained.

[0004] Also, as a method of thinning a wafer and dividing it into a plurality of device chips, a process called DBG (Dicing Before Grinding) has been proposed. In the DBG process, first, grooves with a depth less than the thickness of the wafer are formed along the division planned lines on the surface side of the wafer on which devices are formed (half cut). Then, after a protective tape for protecting the devices is attached to the surface side of the wafer, the back side of the wafer is ground. When the wafer is thinned until the grooves are exposed on the back side of the wafer, the wafer is divided into a plurality of device chips along the division planned lines. By using this DBG process, effects such as suppression of chipping on the back side of the wafer can be obtained, and the processing quality is improved.

[0005] After grinding, foreign matter such as grinding debris and particles (dust, etc.) generated during the grinding process may adhere to the wafer. Therefore, after grinding, the wafer is subjected to a cleaning process (see Patent Documents 1 and 2). For example, the wafer is held on a spinner table, and a cleaning solution is supplied to the wafer while the spinner table is rotated. This washes away foreign matter adhering to the wafer, preventing a deterioration in the quality of the device chip. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2011-176035 [Patent Document 2] Japanese Patent Publication No. 2013-258203 [Overview of the project] [Problems that the invention aims to solve]

[0007] When a workpiece such as a wafer is divided into multiple chips using the aforementioned DBG process, grooves formed in the workpiece are exposed on the back side of the workpiece during grinding. At this time, grinding debris generated by grinding the workpiece may enter the grooves and adhere to the protective tape attached to the front side of the workpiece.

[0008] Foreign matter adhering to the protective tape is removed by a cleaning process performed after grinding the workpiece. However, it has been confirmed that even after cleaning the workpiece divided by the DBG process, foreign matter tends to remain in the central part of the protective tape. This is thought to be because the cleaning fluid supplied to the grooves on the outer circumference of the workpiece is easily discharged from the sides of the workpiece, while the cleaning fluid supplied to the grooves in the central part of the workpiece is not easily discharged, making it difficult to wash away foreign matter adhering to the central part of the protective tape. If foreign matter remains on the protective tape, it may fall off the protective tape and adhere to the chip in subsequent processes (for example, the protective tape peeling process), potentially degrading the quality of the chip.

[0009] This invention has been made in view of the above problems, and aims to provide a method for manufacturing chips that can suppress the remaining foreign matter attached to the protective tape. [Means for solving the problem]

[0010] According to one aspect of the present invention, a method for manufacturing a chip is provided for dividing a workpiece, which is divided into a plurality of regions by a division line, into a plurality of chips, comprising: a groove forming step of forming grooves on the surface side of the workpiece along the division line; a protective tape application step of applying protective tape to the surface side of the workpiece after the groove forming step; a grinding step of dividing the workpiece into a plurality of chips by grinding the back side of the workpiece to expose the grooves after the protective tape application step; and a cleaning step of cleaning the workpiece by supplying a cleaning solution to the back side of the workpiece from a nozzle that moves in a region overlapping with the workpiece while rotating the workpiece, wherein the cleaning step is provided, wherein the nozzle is decelerated when it approaches the rotation axis of the workpiece and accelerated when it moves away from the rotation axis of the workpiece.

[0011] Preferably, in the cleaning step, the nozzle is moved back and forth such that the direction of movement of the nozzle is switched at a position that coincides with the rotation axis of the workpiece. [Effects of the Invention]

[0012] In a method for manufacturing a chip according to one aspect of the present invention, in the cleaning step in which cleaning fluid is supplied from a nozzle to the back side of the workpiece where the groove is exposed, the nozzle is decelerated when it approaches the rotation axis of the workpiece and accelerated when it moves away from the rotation axis of the workpiece. As a result, the central part of the protective tape attached to the workpiece is cleaned intensively, and the remaining foreign matter adhering to the central part of the protective tape is suppressed. [Brief explanation of the drawing]

[0013] [Figure 1] This is a perspective view showing the workpiece. [Figure 2] This is a flowchart showing the manufacturing method of the chip. [Figure 3] This is a perspective view showing the workpiece during the groove forming step. [Figure 4] This is a perspective view showing the workpiece during the protective tape application step. [Figure 5] This is a partial cross-sectional front view showing the workpiece during the grinding step. [Figure 6] Figure 6(A) is a partial cross-sectional front view showing the workpiece during the cleaning step, and Figure 6(B) is a plan view showing the workpiece during the cleaning step. [Figure 7] Figure 7(A) is a cross-sectional view showing a workpiece supported by a frame, and Figure 7(B) is a cross-sectional view showing a workpiece from which protective tape has been removed. [Modes for carrying out the invention]

[0014] Hereinafter, an embodiment according to one aspect of the present invention will be described with reference to the attached drawings. First, an example of the configuration of a workpiece that can be used in the chip manufacturing method according to this embodiment will be described. Figure 1 is a perspective view showing the workpiece 11.

[0015] For example, the workpiece 11 is a disc-shaped wafer made of a semiconductor material such as single-crystal silicon, and has surfaces (first surface) 11a and back surfaces (second surface) 11b that are generally parallel to each other. The workpiece 11 is partitioned into a plurality of rectangular regions by a plurality of division planned lines (streets) 13 arranged in a grid pattern so as to intersect each other. On the surface 11a side of the plurality of regions partitioned by the division planned lines 13, devices 15 such as IC (Integrated Circuit), LSI (Large Scale Integration), LED (Light Emitting Diode), and MEMS (Micro Electro Mechanical Systems) devices are formed respectively.

[0016] However, there is no limitation on the type, material, shape, structure, size, etc. of the workpiece 11. For example, the workpiece 11 may be a substrate (wafer) made of a semiconductor other than silicon (such as GaAs, InP, GaN, SiC, etc.), sapphire, glass, ceramics, resin, metal, etc. Also, there is no limitation on the type, number, shape, structure, size, arrangement, etc. of the devices 15, and the devices 15 may not be formed on the workpiece 11.

[0017] By dividing the workpiece 11 into a grid pattern along the division planned lines 13, a plurality of chips (device chips) each including a device 15 are manufactured. Also, by grinding and thinning the workpiece 11 before or / and after the division of the workpiece 11, a thinned chip can be obtained.

[0018] Next, a specific example of a chip manufacturing method for dividing the workpiece 11 into a plurality of chips using the DBG process will be described. FIG. 2 is a flowchart showing the chip manufacturing method.

[0019] First, a groove is formed along the division planned line 13 on the surface 11a side of the workpiece 11 (groove formation step S1). FIG. 3 is a perspective view showing the workpiece 11 in the groove formation step S1. In FIG. 3, the X-axis direction (machining feed direction, first horizontal direction) and the Y-axis direction (indexing feed direction, second horizontal direction) are perpendicular to each other. Also, the Z-axis direction (vertical direction, height direction, up and down direction) is perpendicular to the X-axis direction and the Y-axis direction.

[0020] For example, in the groove formation step S1, a groove is formed in the workpiece 11 using the cutting device 2. The cutting device 2 includes a chuck table (holding table) 4 for holding the workpiece 11 and a cutting unit 6 for performing cutting on the workpiece 11.

[0021] The upper surface of the chuck table 4 is a flat surface generally parallel to the horizontal plane (XY plane) and constitutes a circular holding surface (not shown) for holding the workpiece 11. The holding surface of the chuck table 4 is connected to a suction source (not shown) such as an ejector through a flow path (not shown), a valve (not shown), etc. formed inside the chuck table 4.

[0022] Also, a moving unit and a rotation drive source are connected to the chuck table 4. The moving unit is constituted by, for example, a ball screw type moving mechanism and moves the chuck table 4 along the X-axis direction. The rotation drive source is constituted by a motor or the like and rotates the chuck table 4 around a rotation axis generally parallel to the Z-axis direction.

[0023] Above the chuck table 4, a cutting unit 6 is provided. The cutting unit 6 includes a columnar housing 8, and a columnar spindle (not shown) arranged along the Y-axis direction is accommodated in the housing 8. The tip end (one end) of the spindle is exposed from the housing 8, and a rotation drive source (not shown) such as a motor is connected to the base end (the other end) of the spindle.

[0024] An annular cutting blade 10 is mounted on the tip of the spindle. The cutting blade 10 rotates around a rotation axis that is approximately parallel to the Y-axis direction by power transmitted from the rotation drive source through the spindle.

[0025] As the cutting blade 10, for example, a hub-type cutting blade (hub blade) can be used. The hub blade comprises an annular hub base made of metal or the like, and an annular cutting edge formed along the outer edge of the hub base. The cutting edge of the hub blade is made of an electroformed grinding wheel containing abrasive grains made of diamond or the like, and a binder such as a nickel plating layer that fixes the abrasive grains. However, there are no restrictions on the materials of the abrasive grains and the binder. Alternatively, a washer-type cutting blade (washer blade) may be used as the cutting blade 10. The washer blade consists only of an annular cutting edge in which abrasive grains made of diamond or the like are fixed by a binder made of metal, ceramics, resin, etc.

[0026] The cutting blade 10, mounted on the tip of the spindle, is covered by a blade cover 12 fixed to the housing 8. The blade cover 12 includes a pair of connection parts 14 connected to a pipe (not shown) to which a liquid (cutting fluid) such as pure water is supplied, and a pair of nozzles 16 connected to the connection parts 14. The pair of nozzles 16 are positioned on the front and back sides of the cutting blade 10, sandwiching the lower part of the cutting blade 10. Each of the pair of nozzles 16 is also provided with a supply port (not shown) that opens toward the cutting blade 10.

[0027] When the cutting blade 10 cuts the workpiece 11, cutting fluid is supplied to the connection part 14, and the cutting fluid is sprayed from the supply ports of the pair of nozzles 16 toward both sides (front and back) of the cutting blade 10. This cools the workpiece 11 and the cutting blade 10, and washes away the debris (cutting chips) generated by the cutting process.

[0028] A moving unit (not shown) is connected to the cutting unit 6. The moving unit is composed of, for example, a ball screw type moving mechanism and moves the cutting unit 6 along the Y-axis and Z-axis directions.

[0029] When cutting the workpiece 11 with the cutting device 2, the workpiece 11 is supported by an annular frame 17 for the convenience of handling (transporting, holding, etc.) the workpiece 11. The frame 17 is made of a metal such as SUS (stainless steel), aluminum, or a hard resin, and is formed in the shape of a thin plate. A circular opening 17a is provided in the center of the frame 17, penetrating the frame 17 in the thickness direction. The diameter of the opening 17a is larger than the diameter of the workpiece 11, allowing the workpiece 11 to be placed inside the opening 17a.

[0030] A tape (dicing tape) 19 supporting the workpiece 11 is attached to the workpiece 11 and the frame 17. For example, the tape 19 includes a circularly formed film-like base material and an adhesive (glue) provided on the base material. The base material is made of a resin such as polyolefin, polyvinyl chloride, or polyethylene terephthalate. The adhesive is made of an epoxy, acrylic, or rubber-based adhesive. The adhesive may also be an ultraviolet-curable resin.

[0031] With the workpiece 11 positioned inside the opening 17a of the frame 17, the central part of the tape 19 is attached to the back surface 11b of the workpiece 11, and the outer periphery of the tape 19 is attached to the frame 17. As a result, the workpiece 11 is supported by the frame 17 via the tape 19.

[0032] When cutting the workpiece 11, the workpiece 11 is first held by the chuck table 4. Specifically, the workpiece 11 is placed on the chuck table 4 with its front surface 11a facing upwards and its back surface 11b (tape 19 side) facing the holding surface. In addition, multiple clamps (not shown) are provided around the chuck table 4 to grip and fix the frame 17. Once the workpiece 11 is placed on the chuck table 4, the frame 17 is fixed by the multiple clamps. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface of the chuck table 4, the workpiece 11 is held by the chuck table 4 via the tape 19.

[0033] Next, the workpiece 11 is cut along the planned division line 13 using the cutting blade 10. Specifically, first, the chuck table 4 is rotated to align the length of the predetermined planned division line 13 with the X-axis direction. Also, the position of the cutting unit 6 in the Y-axis direction is adjusted so that the cutting blade 10 aligns with the extension of the predetermined planned division line 13.

[0034] Furthermore, the height of the cutting unit 6 is adjusted so that the lower end of the cutting blade 10 is positioned below the surface 11a and above the back surface 11b in the Z-axis direction. The difference in height (position in the Z-axis direction) between the surface 11a of the workpiece 11 and the lower end of the cutting blade 10 at this time corresponds to the cutting depth of the cutting blade 10 into the workpiece 11. The cutting depth of the cutting blade 10 is set to be greater than or equal to the target thickness (finished thickness) of the workpiece 11 after the grinding step S3 (see Figure 5) described later.

[0035] Then, while rotating the cutting blade 10, the chuck table 4 is moved along the X-axis. As a result, the chuck table 4 and the cutting blade 10 move relative to each other along the X-axis (machining feed), and the cutting blade 10 cuts into the surface 11a side of the workpiece 11 along the predetermined division line 13. As a result, grooves 11c (cutting grooves) with a depth greater than or equal to the finish thickness are formed on the surface 11a side of the workpiece 11 along the division line 13.

[0036] Subsequently, the same procedure is repeated to cut the workpiece 11 along the other division lines 13. When the workpiece 11 is cut along all the division lines 13, a workpiece 11 with a grid-like groove 11c is obtained (see Figure 4). After the cutting of the workpiece 11 is complete, the tape 19 is peeled off the workpiece 11, and the support of the workpiece 11 by the frame 17 is released.

[0037] The method for forming the groove 11c is not limited to cutting with the cutting blade 10. For example, in the groove formation step S1, the groove 11c (laser-processed groove) may be formed in the workpiece 11 by laser processing.

[0038] Specifically, the workpiece 11 is subjected to ablation by irradiating it with a laser beam. In this case, the laser beam irradiation conditions are set so that the area of ​​the workpiece 11 irradiated with the laser beam is removed by ablation. More specifically, the wavelength of the laser beam is set so that at least a portion of the laser beam is absorbed by the workpiece 11. That is, the workpiece 11 is irradiated with a laser beam of a wavelength that is absorbed by the workpiece 11. Other irradiation conditions of the laser beam are also set as appropriate so that the ablation process is properly performed on the workpiece 11.

[0039] Then, with the laser beam's focusing point positioned on the planned division line 13 of the workpiece 11, the laser beam is irradiated from the surface 11a side of the workpiece 11 along the planned division line 13. As a result, the area of ​​the surface 11a side of the workpiece 11 along the planned division line 13 is removed by ablation, and a groove 11c is formed on the surface 11a side of the workpiece 11. In addition, the groove 11c can also be formed on the workpiece 11 by wet etching or plasma etching.

[0040] Next, protective tape is applied to the surface 11a side of the workpiece 11 (protective tape application step S2). Figure 4 is a perspective view showing the workpiece 11 in protective tape application step S2.

[0041] In the protective tape application step S2, a protective tape 21 is applied to the surface 11a side of the workpiece 11, with a size that can cover the entire surface 11a side of the workpiece 11. For example, a protective tape 21 formed in a circular shape with approximately the same diameter as the workpiece 11 is applied so as to cover multiple devices 15. This protects the surface 11a side of the workpiece 11 and the devices 15.

[0042] The protective tape 21 comprises a film-like base material and an adhesive layer (glue layer) provided on the base material. For example, the base material is made of a resin such as polyolefin, polyvinyl chloride, or polyethylene terephthalate, and the adhesive layer is made of an epoxy, acrylic, or rubber-based adhesive. The adhesive layer may also be made of an ultraviolet-curing resin that hardens when exposed to ultraviolet light.

[0043] The protective tape 21 may be formed into a circular shape after being attached to the workpiece 11. For example, after attaching a rectangular protective tape 21 to the workpiece 11, the protective tape 21 can be cut in a ring shape along the outer edge of the workpiece 11 to obtain a protective tape 21 with approximately the same diameter as the workpiece 11.

[0044] Next, the workpiece 11 is divided into multiple chips by grinding the back surface 11b side of the workpiece 11 to expose the groove 11c (grinding step S3). Figure 5 is a partial cross-sectional front view showing the workpiece 11 in grinding step S3.

[0045] For example, in grinding step S3, the workpiece 11 is ground using a grinding device 20. The grinding device 20 includes a chuck table (holding table) 22 for holding the workpiece 11 and a grinding unit 24 for performing grinding on the workpiece 11.

[0046] The upper surface of the chuck table 22 forms a circular holding surface 22a for holding the workpiece 11. The holding surface 22a is connected to a suction source (not shown), such as an ejector, via a flow path (not shown), a valve (not shown), etc., formed inside the chuck table 22.

[0047] A moving unit (not shown) and a rotational drive source (not shown) are connected to the chuck table 22. The moving unit is composed of, for example, a ball screw type moving mechanism or a turntable, and moves the chuck table 22 along the horizontal direction. The rotational drive source is composed of a motor or the like, and rotates the chuck table 22 around a rotation axis that is approximately perpendicular to the radial direction of the holding surface 22a.

[0048] A grinding unit 24 is positioned above the chuck table 22. The grinding unit 24 includes a cylindrical spindle 26 arranged vertically. A disc-shaped wheel mount 28 made of metal or the like is fixed to the tip (lower end) of the spindle 26. A rotational drive source (not shown), such as a motor, is connected to the base (upper end) of the spindle 26 to rotate the spindle 26.

[0049] A grinding wheel 30 for grinding the workpiece 11 is mounted on the lower side of the wheel mount 28. The grinding wheel 30 is made of a metal such as stainless steel or aluminum and includes an annular wheel base 32 formed to be approximately the same diameter as the wheel mount 28.

[0050] Multiple grinding wheels 34 are fixed to the lower surface of the wheel base 32. The grinding wheels 34 are formed by fixing abrasive grains, such as diamond or cBN (cubic boron nitride), with a binder (bonding material) such as metal bond, resin bond, or vitrified bond. For example, multiple rectangular parallelepiped-shaped grinding wheels 34 are arranged in a ring shape at roughly equal intervals along the outer edge of the wheel base 32.

[0051] The grinding wheel 30 rotates around a rotation axis that is approximately parallel to the vertical direction by power transmitted from a rotational drive source via a spindle 26 and a wheel mount 28. A moving unit (not shown) is also connected to the grinding unit 24. The moving unit is composed of, for example, a ball screw type moving mechanism and moves (raises and lowers) the grinding unit 24 along the vertical direction. Furthermore, a nozzle 36 for supplying a grinding fluid 38 such as pure water is provided near the grinding unit 24.

[0052] When grinding the workpiece 11, the workpiece 11 is first held by the chuck table 22. Specifically, the workpiece 11 is placed on the chuck table 22 such that the front surface 11a (protective tape 21 side) faces the holding surface 22a and the back surface 11b is exposed upwards. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 22a, the workpiece 11 is held by the chuck table 22 through the protective tape 21.

[0053] Next, the chuck table 22 is positioned below the grinding unit 24. Then, while rotating the chuck table 22 and the grinding wheel 30, the grinding wheel 30 is lowered toward the chuck table 22. As a result, multiple grinding wheels 34 rotate and come into contact with the back surface 11b of the workpiece 11, and the back surface 11b of the workpiece 11 is ground away. Consequently, the back surface 11b of the workpiece 11 is ground, and the workpiece 11 is thinned.

[0054] When the workpiece 11 is ground down to its finished thickness, the grooves 11c formed in the workpiece 11 are exposed on the back surface 11b. As a result, the workpiece 11 is divided along the planned division line 13. In this way, the workpiece 11 is divided into multiple chips (device chips) 23, each equipped with a device 15 (see Figure 1). Subsequently, the grinding unit 24 rises, the grinding wheel 34 moves away from the workpiece 11, and grinding of the workpiece 11 stops.

[0055] When the workpiece 11 is ground with the grinding wheel 30, grinding chips are generated in the contact area between the workpiece 11 and the grinding wheel 34. In grinding step S3, the workpiece 11 is ground until the groove 11c is exposed on the back surface 11b, so grinding chips enter the exposed groove 11c towards the end of grinding. As a result, the grinding chips adhere to the adhesive layer of the protective tape 21 that is exposed inside the groove 11c.

[0056] Next, the workpiece 11 is cleaned by supplying cleaning fluid to the back surface 11b side of the workpiece 11 (cleaning step S4). Figure 6(A) is a partial cross-sectional front view showing the workpiece 11 in cleaning step S4, and Figure 6(B) is a plan view showing the workpiece 11 in cleaning step S4.

[0057] In cleaning step S4, the workpiece 11 after grinding is cleaned in a cleaning device (cleaning unit) 40. The cleaning device 40 includes a spinner table (chuck table) 42 that holds and rotates the workpiece 11, and a cleaning fluid supply unit 44 that supplies cleaning fluid. The cleaning device 40 may be installed independently of the grinding device 20 (see Figure 5), or it may be part of the grinding device 20.

[0058] The upper surface of the spinner table 42 is a flat surface that is generally parallel to the horizontal plane and constitutes a circular holding surface 42a for holding the workpiece 11. The holding surface 42a is connected to a suction source (not shown), such as an ejector, via a flow path (not shown), a valve, etc., formed inside the spinner table 42. The spinner table 42 is also connected to a rotational drive source (not shown), such as a motor, which rotates the spinner table 42 around a rotation axis that is generally parallel to the vertical direction.

[0059] The cleaning fluid supply unit 44 comprises an L-shaped support arm 46, a rotational drive source 48 such as a motor for rotating the support arm 46, and a nozzle 50 for supplying cleaning fluid 52. The nozzle 50 is fixed to the tip (one end) of the support arm 46, and the rotational drive source 48 is connected to the base (other end) of the support arm 46.

[0060] The nozzle 50 is equipped with a circular nozzle 50a for spraying cleaning fluid 52. The nozzle 50 is also connected to a cleaning fluid supply source (not shown) that supplies cleaning fluid 52 to the nozzle 50. For example, a liquid such as pure water, or a mixed fluid containing a liquid (such as water) and a gas (such as air), is supplied from the fluid supply source to the nozzle 50 and sprayed from the nozzle 50a.

[0061] When the rotary drive source 48 is driven, the support arm 46 and nozzle 50 rotate, and the spinner table 42 and nozzle 50 move relative to each other along a direction parallel to the holding surface 42a (horizontal direction). This allows the nozzle 50 to be positioned in a position that overlaps with the holding surface 42a (supply position) and in a position that does not overlap with the holding surface 42a (retracted position).

[0062] When cleaning the workpiece 11, the workpiece 11 is first held by the spinner table 42. Specifically, the workpiece 11 is placed on the spinner table 42 such that the front surface 11a (protective tape 21 side) faces the holding surface 42a and the back surface 11b is exposed upwards. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 42a, the workpiece 11 is held by the spinner table 42 via the protective tape 21.

[0063] When cleaning the workpiece 11 with the cleaning device 40, the workpiece 11 may be supported by a frame 17 (see Figure 3). In this case, the frame 17 is gripped and fixed by a plurality of clamps (not shown) provided around the spinner table 42.

[0064] Next, the support arm 46 rotates so that the nozzle 50 is positioned to overlap with the workpiece 11, and the nozzle's nozzle opening 50a faces the back surface 11b of the workpiece 11. In this state, when the spinner table 42 is rotated and the cleaning fluid 52 is sprayed from the nozzle opening 50a of the nozzle 50, the cleaning fluid 52 is supplied to the back surface 11b of the workpiece 11. As a result, the workpiece 11 is cleaned, and foreign matter such as grinding chips and particles (dust, etc.) adhering to the workpiece 11 is washed away.

[0065] In addition, during the cleaning step S4, foreign matter such as grinding debris adhering to the adhesive layer of the protective tape 21 exposed inside the groove 11c is also washed away. Here, the cleaning liquid 52 supplied to the groove 11c on the outer circumference of the workpiece 11 is easily discharged from the side of the workpiece 11, while the cleaning liquid 52 supplied to the groove 11c in the center of the workpiece 11 is not easily discharged. Therefore, foreign matter adhering to the center of the protective tape 21 tends to remain without being washed away by the cleaning liquid 52.

[0066] Therefore, in this embodiment, during the cleaning of the workpiece 11, the nozzle 50 is decelerated when it approaches the rotation axis of the workpiece 11, and accelerated when it moves away from the rotation axis of the workpiece 11. As a result, the period during which the nozzle 50 is positioned above the central part of the workpiece 11 is extended, and the central part of the protective tape 21 is cleaned thoroughly. Consequently, the remaining foreign matter adhering to the central part of the protective tape 21 is suppressed.

[0067] In cleaning step S4, while the workpiece 11 is rotated by the spinner table 42, cleaning fluid 52 is supplied from the nozzle 50, and the nozzle 50 is moved in the region overlapping with the workpiece 11. For example, the nozzle 50 reciprocates between a position that overlaps with the outer edge of the workpiece 11 (outer edge overlap position) and a position that overlaps with the axis of rotation of the workpiece 11 (center of the workpiece 11) (axis of rotation overlap position). Figure 6(B) illustrates the nozzle 50 moving along a path (forward path) A from the outer edge overlap position to the axis of rotation overlap position, and a path (forward path) B from the axis of rotation overlap position to the outer edge overlap position. In this case, the nozzle 50 reciprocates such that the direction of movement switches to the opposite direction at the position that overlaps with the axis of rotation of the workpiece 11 (axis of rotation of the spinner table 42).

[0068] Then, as the nozzle 50 moves along path A and approaches the rotation axis overlap position from the outer edge overlap position, the moving speed (swivel speed) of the nozzle 50 is reduced. For example, the nozzle 50 may be gradually decelerated over the entire length of path A, or the nozzle 50 may be decelerated only during the period after the nozzle 50 is positioned within a predetermined range from the rotation axis overlap position. As a result, while the nozzle 50 is moving along path A, the amount of cleaning fluid 52 supplied to the central part of the workpiece 11 and protective tape 21 is greater than the amount of cleaning fluid 52 supplied to the outer periphery of the workpiece 11 and protective tape 21.

[0069] Furthermore, as the nozzle 50 moves along path B and away from the rotation axis superimposed position, the movement speed (swivel speed) of the nozzle 50 is increased. For example, the nozzle 50 may be gradually accelerated over the entire length of path B, or it may be accelerated only during the period after the nozzle 50 is positioned outside a predetermined range from the rotation axis superimposed position. This ensures that while the nozzle 50 is moving along path B, the amount of cleaning fluid 52 supplied to the central part of the workpiece 11 and protective tape 21 is greater than the amount of cleaning fluid 52 supplied to the outer periphery of the workpiece 11 and protective tape 21.

[0070] As described above, by moving the nozzle 50 and supplying the cleaning solution 52, the central parts of the workpiece 11 and the protective tape 21 are cleaned intensively. This makes it easier to remove foreign matter that is stuck to the central part of the protective tape 21.

[0071] The supply conditions for the cleaning solution 52 can be appropriately set according to the material, shape, size, etc., of the workpiece 11 and the protective tape 21. For example, a mixed fluid containing pure water and air can be used as the cleaning solution 52. Also, for example, the pressure of the cleaning solution 52 can be set to 0.2 MPa or more and 0.6 MPa or less, the flow rate of the cleaning solution 52 to 150 ml / min or more and 250 ml / min or less, the rotation speed of the support arm 46 and nozzle 50 to 18° / s or more and 36° / s or less, and the cleaning time to 20 seconds or more and 40 seconds or less.

[0072] Furthermore, in the cleaning step S4, the nozzle 50 may be temporarily stopped at a position that coincides with the rotation axis of the workpiece 11, or at a position within a predetermined distance from the rotation axis of the workpiece 11. This allows the cleaning fluid 52 to be supplied intensively to the central part of the workpiece 11 and the protective tape 21 for a certain period of time, making it easier to remove foreign matter adhering to the central part of the protective tape 21. However, in order to ensure that the outer periphery of the workpiece 11 and the protective tape 21 is not insufficiently cleaned, the stopping time of the nozzle 50 is preferably 1 / 5 or less of the total cleaning time of the workpiece 11, and preferably 1 / 10 or less.

[0073] Next, the protective tape 21 is peeled off the workpiece 11 (protective tape peeling step S5). The workpiece 11 and protective tape 21 in protective tape peeling step S5 are shown in Figures 7(A) and 7(B). Figure 7(A) is a cross-sectional view showing the workpiece 11 supported by the frame 25, and Figure 7(B) is a cross-sectional view showing the workpiece 11 from which the protective tape 21 has been peeled off.

[0074] When peeling the protective tape 21 from the workpiece 11, the workpiece 11 is first supported by an annular frame 25. A circular opening 25a is provided in the center of the frame 25. Tape 27 is attached to the frame 25 so as to cover the opening 25a. The shape, structure, and material of the frame 25 and tape 27 are the same as those of the frame 17 and tape 19 (see Figure 3).

[0075] The workpiece 11, which has been cleaned in cleaning step S4, is positioned so that its back surface 11b is in contact with the adhesive layer of the tape 27, which is exposed inside the opening 25a of the frame 25. As a result, the tape 27 is attached to the back surface 11b of the workpiece 11, and the workpiece 11 is supported by the frame 25 via the tape 27.

[0076] Next, with the frame 25 fixed in place, one end of the protective tape 21 attached to the workpiece 11 is grasped and moved to the other end of the protective tape 21. This causes the protective tape 21 to peel off and be removed from the surface 11a side of the workpiece 11. Note that the adhesive force of the protective tape 21 to the workpiece 11 is weaker than the adhesive force of the tape 27 to the workpiece 11. Therefore, no chips 23 remain on the peeled protective tape 21.

[0077] Here, any foreign matter adhering to the protective tape 21 is removed by the protective tape peeling step S5 described above (see Figures 6(A) and 6(B)). Therefore, when peeling the protective tape 21 from the workpiece 11, there is no need to worry about foreign matter adhering to the protective tape 21 falling off and adhering to the chip 23. This prevents a deterioration in the quality of the chip 23 due to the adhesion of foreign matter.

[0078] In the above description, we explained an example in which the protective tape 21 is peeled off while the frame 25 supporting the workpiece 11 is fixed. However, there are no restrictions on how the workpiece 11 is fixed. For example, instead of supporting the workpiece 11 with the frame 25, the workpiece 11 may be held in place by suction using a chuck table.

[0079] As described above, in the chip manufacturing method according to this embodiment, in the cleaning step S4 in which cleaning liquid 52 is supplied from the nozzle 50 to the back surface 11b side of the workpiece 11 where the groove 11c is exposed, the nozzle 50 is decelerated when it approaches the rotation axis of the workpiece 11, and the nozzle 50 is accelerated when it moves away from the rotation axis of the workpiece 11. As a result, the central part of the protective tape 21 attached to the workpiece 11 is cleaned intensively, and the remaining foreign matter adhering to the central part of the protective tape 21 is suppressed.

[0080] In the above embodiment, a configuration was described in which the direction of movement of the nozzle 50 is switched at a position that coincides with the rotation axis of the workpiece 11 (see Figure 6(B)). However, there are no restrictions on the movement path of the nozzle 50 as long as the cleaning fluid 52 can be supplied to the entire workpiece 11.

[0081] For example, the nozzle 50 may be moved back and forth along an arc-shaped path that passes through two different points on the outer edge of the workpiece 11 (first outer edge overlapping position and second outer edge overlapping position) and a position that overlaps with the rotation axis of the workpiece 11 (rotation axis overlapping position). In this case, the nozzle 50 moves in an arc from the first outer edge overlapping position, through the rotation axis overlapping position, to the second outer edge overlapping position (forward path), and then moves in an arc from the second outer edge overlapping position, through the rotation axis overlapping position, to the first outer edge overlapping position (return path).

[0082] When cleaning the workpiece 11 with the nozzle 50 moving as described above, the nozzle 50 decelerates as it approaches the rotation axis overlap position from the first outer edge overlap position, and as it approaches the rotation axis overlap position from the second outer edge overlap position. In addition, the nozzle 50 accelerates as it moves away from the rotation axis overlap position to the second outer edge overlap position, and as it moves away from the rotation axis overlap position to the first outer edge overlap position.

[0083] Furthermore, the structures, methods, etc., according to the above embodiments can be modified as appropriate without departing from the scope of the objectives of the present invention. [Explanation of Symbols]

[0084] 11 Workpiece 11a Surface (first side) 11b Back side (2nd side) 11c groove 13 planned division lines (street) 15 devices 17 frames 17a aperture 19 Tape (Dicing Tape) 21 Protective Tape 23 Chips (Device Chips) 25 frames 25a opening 27 Tapes 2 Cutting equipment 4. Chuck table (holding table) 6 Cutting Units 8 Housing 10 cutting blades 12 Blade Covers 14 Connection part 16 nozzles 20 Grinding equipment 22 Chuck table (holding table) 22a Holding surface 24 Grinding Units 26 spindles 28 Wheel Mount 30 grinding wheels 32 Wheel base 34 Grinding Wheels 36 nozzles 38. Grinding fluid 40. Cleaning device (cleaning unit) 42 Spinner Table (Chuck Table) 42a Holding surface 44 Cleaning fluid supply unit 46 Support Arm 48 Rotary drive source 50 nozzles 50a nozzle 52 Cleaning solution

Claims

1. A method for manufacturing chips, which divides a workpiece partitioned into multiple regions by a planned division line into multiple chips, A groove forming step in which grooves are formed on the surface side of the workpiece along the planned division line, After the groove forming step, a protective tape application step is performed in which protective tape is applied to the surface side of the workpiece. A grinding step is performed after the protective tape application step, in which the back side of the workpiece is ground to expose the groove, thereby dividing the workpiece into a plurality of chips. The process includes, after the grinding step, a cleaning step in which the workpiece is cleaned by supplying a cleaning solution to the back side of the workpiece from a nozzle that moves over the area overlapping the workpiece while the workpiece is rotating, A method for manufacturing a chip, characterized in that, in the cleaning step, the nozzle is decelerated when it approaches the rotation axis of the workpiece, and the nozzle is accelerated when it moves away from the rotation axis of the workpiece.

2. The method for manufacturing a chip according to claim 1, characterized in that, in the cleaning step, the nozzle is moved back and forth such that the direction of movement of the nozzle is switched at a position that overlaps with the rotation axis of the workpiece.

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