Processing equipment

Abstract

To provide a processing device that improves the processing quality of wafers. [Solution] The processing device 1 is an apparatus that uses a grinding wheel 10a to process the peripheral portion of a wafer W having a main surface perpendicular to the thickness direction, and is equipped with a wafer holding unit 2 that holds the wafer W, a rotational drive unit 3a that rotates the grinding wheel 10a around a rotation axis 31a parallel to the main surface of the wafer W, an arm unit 4a that holds the rotational drive unit 3a and moves in a first direction that is the thickness direction, a moving mechanism 20 that changes the position of the arm unit 4a relative to the wafer holding unit 2 in a second direction different from the first direction, a grinding fluid discharge device 5a, and a nozzle 50a provided in the grinding fluid discharge device 5a and formed with a grinding fluid discharge port, and is characterized in that the grinding fluid discharge device 5a changes the discharge direction of the grinding fluid from the nozzle 50a depending on the contact position between the grinding wheel 10a and the wafer W.

Description

[Technical Field]

[0001] The present invention relates to a processing device. [Background technology]

[0002] For example, as described in Patent Document 1, a processing device is known that brings a rotating grinding wheel into contact with the peripheral edge of a plate-shaped wafer to shape the peripheral edge into a predetermined shape. To improve wafer quality by preventing scratches, chips, ripples, etc. from occurring on the wafer and to extend the life of the grinding wheel, a grinding fluid is discharged during processing in this processing device. Conventionally, the location where the grinding fluid is sprayed has been fixed to a predetermined position on the grinding wheel away from the contact position with the wafer (for example, a position where the grinding wheel is rotated approximately 180° from the contact position between the rotating grinding wheel and the wafer). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5112703 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the contact position between the grinding wheel and the peripheral edge of the wafer changes as the processing progresses. Despite this, conventional processing equipment, in which the position where the grinding fluid is applied is fixed, does not apply enough grinding fluid to the contact position between the grinding wheel and the wafer, so the grinding fluid is not effective enough. Also, it is possible to increase the number of nozzles that discharge the grinding fluid so that the grinding fluid is applied to the contact position as much as possible even if the contact position between the grinding wheel and the wafer changes, but this increases the complexity of the equipment and causes the problem that the grinding fluid is not applied sufficiently to the contact position.

[0005] The present invention has been made in view of the above circumstances, and has as its object to provide a processing apparatus in which the effect of the grinding fluid is fully exerted and the processed quality of the wafer is improved. [Means for solving the problem]

[0006] The present invention includes the embodiments shown below.

[0007] [1] A processing device for processing and shaping a peripheral portion of a plate-shaped wafer having a predetermined thickness and a main surface perpendicular to the thickness direction by contacting a rotating grinding wheel, the processing device comprising: a wafer holding unit for holding the wafer; a rotation drive unit for holding the grinding wheel and rotating the grinding wheel around a rotation axis extending parallel to the main surface of the wafer; an arm unit for holding the rotation drive unit and movable in a first direction which is the thickness direction; a movement mechanism for changing the position of the arm unit relative to the wafer holding unit in a second direction different from the first direction, thereby being able to bring the grinding wheel into contact with and separate the peripheral portion of the wafer; a grinding fluid discharge device provided on the arm unit for discharging a grinding fluid during processing of the wafer; and a nozzle provided on the grinding fluid discharge device and having a discharge port for the grinding fluid, the grinding fluid discharge device being able to change the discharge direction of the grinding fluid from the nozzle depending on the contact position of the grinding wheel and the wafer. Change to face the contact position , processing equipment.

[0008] [2] The grinding fluid discharge device adjusts the discharge direction from the nozzle depending on the position of the arm unit relative to the wafer holder in the first direction. Change to face the contact position The processing device described in [1].

[0009] [3] The grinding fluid discharge device includes a nozzle moving mechanism that moves the nozzle along an arcuate orbit formed around the rotation axis of the grinding wheel, and the nozzle moves along the arcuate orbit to change the discharge direction. Toward the contact position The processing device according to [1] or [2], which is changed.

[0010] [4] A driving force for changing the position of the arm portion relative to the wafer holder in the first direction is transmitted to the nozzle moving mechanism, whereby the nozzle moves along the arcuate orbit to change the discharge direction. Toward the contact position The processing device according to [3], which is modified.

[0011] [5] The processing apparatus described in [3] or [4], wherein the nozzle moving mechanism comprises a guide member that moves integrally with the nozzle on the arcuate orbit, and a guide member that guides the guide member to move on the arcuate orbit.

[0012] [6] The nozzle moving mechanism comprises a rack gear that is independent of the arm portion and extends in the first direction, an arcuate track gear provided on the guide member, and a pinion gear that meshes with the rack gear and the arcuate track gear, and when the arm portion moves in the first direction, the pinion gear and the arcuate track gear rotate, causing the guide member to move on the arcuate track. [5] The processing apparatus described in

[0013] [7] The processing device according to [5] or [6], wherein the ejection direction from the nozzle relative to the predetermined direction of the guide member is changeable. [Effects of the Invention]

[0014] According to this embodiment, the effect of the grinding fluid is fully exerted, and the processed quality of the wafer is improved. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 2 is a view of the processing device according to the embodiment as seen from the right. [Figure 2] FIG. 2 is a top view of the processing apparatus according to the embodiment. [Figure 3] 1 is a cross-sectional view of the peripheral portion of a wafer after shaping. [Figure 4] A top view of the left and right grinding fluid discharge devices and their surroundings. [Figure 5] FIG. [Figure 6]A view of the grinding fluid discharge device on the left from the right. [Figure 7] FIG. 7 is a diagram of FIG. 6 with the screws and arcuate orbital gear of the nozzle holding member removed. [Figure 8] Left view of the coolant discharge device on the right. [Figure 9] FIG. 1 is a block diagram showing a configuration of a processing apparatus according to an embodiment. [Figure 10] A view of the left and right grinding wheels when processing the peripheral edge surface of a wafer, viewed from the right. [Figure 11] Right view of the left and right grinding wheels when processing the slope of a wafer. DETAILED DESCRIPTION OF THE INVENTION

[0016] First, the structure of the processing apparatus 1 of this embodiment will be described. The processing apparatus 1 of this embodiment shown in Figures 1 and 2 is an apparatus that grinds the peripheral edge of a wafer W for semiconductor devices by bringing the outer surfaces of rotating grindstones 10a and 10b into contact with the peripheral edge, thereby shaping the peripheral edge into a predetermined shape.

[0017] The wafer W is a disk-shaped wafer having a predetermined thickness. The wafer W has an upper surface W1 and a lower surface W2 (see FIG. 3) as main surfaces perpendicular to the thickness direction. The upper surface W1 and the lower surface W2 are substantially circular flat surfaces when viewed from above and below. The peripheral edge of the wafer W is shaped into a shape consisting of an upper inclined surface Wa1 that continues from the upper surface W1 and is inclined relative to the upper surface W1, a peripheral edge surface Wb that is the radially outer end surface of the wafer W and is perpendicular to the upper surface W1 and the lower surface W2, an upper arcuate surface Wc1 that smoothly connects the upper inclined surface Wa1 and the peripheral edge surface Wb, a lower inclined surface Wa2 that continues from the lower surface W2 and is inclined relative to the lower surface W2, and a lower arcuate surface Wc2 that smoothly connects the lower inclined surface Wa2 and the peripheral edge surface Wb, as shown in FIG. 3.

[0018] As shown in Figures 1 and 2, the processing device 1 includes a wafer holding unit 2 that holds a wafer W, left and right rotation drive units 3a and 3b that hold and rotate grinding wheels 10a and 10b, left and right arm units 4a and 4b that hold the rotation drive units 3a and 3b and can move in the vertical direction, a movement mechanism 20 that changes the position of the wafer holding unit 2 relative to the arm units 4a and 4b, and left and right grinding fluid discharge devices 5a and 5b that discharge grinding fluid during processing of the wafer W.

[0019] The wafer holding unit 2 includes a circular stage 21 on which the wafer W is placed, a stage rotation device 22 that rotates the stage 21, and a suction device 23 (see FIG. 9) that suction-holds the wafer W onto the stage 21. The wafer W is placed on the stage 21 with its upper surface W1 and lower surface W2 as horizontal planes. The suction device 23 suction-holds the wafer W placed on the stage 21 and holds it on the stage 21. The stage 21 has a smaller radius than the wafer W, and when the wafer W is placed on the stage 21 and its center coincides with the center of rotation of the stage 21, the peripheral edge of the wafer W extends radially outward from the stage 21.

[0020] The moving mechanism 20 changes the horizontal distance between the wafer holder 2 and the arm units 4a and 4b, and more specifically, moves the wafer holder 2 in the horizontal direction. In this way, the moving mechanism 20 brings the peripheral edge of the wafer W held by the wafer holder 2 into contact with or separates the grinding wheels 10a and 10b held by the arm units 4a and 4b. The moving mechanism 20 also moves the contact position between the grinding wheels 10a and 10b and the wafer W in the wafer radial direction. Note that the "wafer radial direction" refers to the radial direction of the wafer W.

[0021] In the following description, the movement direction of the wafer holder 2 is referred to as the front-to-rear direction, the direction in which the wafer holder 2 moves away from the arm portions 4a and 4b is referred to as the front, and the direction in which the wafer holder 2 moves toward the arm portions 4a and 4b is referred to as the rear. Furthermore, the left-to-right direction refers to the left-to-right direction when viewing the arm portions 4a and 4b from the wafer holder 2 side.

[0022] The rotary drive units 3a and 3b are provided on the left and right sides, respectively. As shown in Fig. 4, the rotary drive units 3a and 3b on the left and right sides include spindle motors 30a and 30b and rotary shafts 31a and 31b of the spindle motors 30a and 30b, respectively.

[0023] The rotation shafts 31a, 31b extend in a direction parallel to the upper surface W1 and the lower surface W2 of the wafer W, i.e., in the horizontal direction. The rotation shafts 31a, 31b also extend in the left-right direction. Disk-shaped grinding wheels 10a, 10b are provided at the tips of the rotation shafts 31a, 31b and are rotatable around the rotation shafts 31a, 31b. The rotation shafts 31a, 31b of the spindle motors 30a, 30b can also be referred to as the rotation shafts 31a, 31b of the grinding wheels 10a, 10b.

[0024] The left and right rotational drive units 3a and 3b are arranged with the grinding wheels 10a and 10b facing each other. As shown in FIG. 4, the left and right grinding wheels 10a and 10b are adjacent to each other with their surfaces perpendicular to the rotation shafts 31a and 31b facing each other. The pair of left and right spindle motors 30a and 30b rotate the left and right grinding wheels 10a and 10b in opposite directions around the rotation shafts 31a and 31b. On the left side, the grinding wheel 10a rotates so that it strikes the peripheral edge of the wafer W from top to bottom. On the right side, the grinding wheel 10b rotates so that it strikes the peripheral edge of the wafer W from bottom to top. The rotational directions of the grinding wheels 10a and 10b are indicated by dashed arrows in FIGS. 6, 8, and 11.

[0025] In the following description, the space between the left and right grindstones 10a and 10b is referred to as the center in the left-right direction, and the side opposite to the center in the left-right direction is referred to as the outer side in the left-right direction.

[0026] The arm portions 4a and 4b are also provided on the left and right sides. Each of the left and right arm portions 4a and 4b extends vertically and has a grip portion 40a or 40b extending forward from its lower end. The grip portions 40a and 40b hold the rotation drive portions 3a and 3b on the outside of the grinding wheels 10a and 10b in the left-right direction.

[0027] A vertical movement device 41 (see FIG. 9) is provided as a device for moving the arm units 4a, 4b in the thickness direction of the wafer W, i.e., in the vertical direction. The vertical movement device 41 moves the left and right arm units 4a, 4b separately in the vertical direction. When the arm units 4a, 4b move in the vertical direction, the rotation drive units 3a, 3b and grinding wheels 10a, 10b held by the arm units 4a, 4b also move in the vertical direction integrally with the arm units 4a, 4b.

[0028] The grinding fluid discharge devices 5a, 5b are provided on the left and right arm portions 4a, 4b, respectively. As shown in Figures 4 to 8, the left and right grinding fluid discharge devices 5a, 5b each include a nozzle 50a, 50b having a grinding fluid discharge port formed therein, and a nozzle moving mechanism 51a, 51b for moving the nozzle 50a, 50b. The nozzle moving mechanism 51a, 51b includes guide members 52a, 52b, guide members 53a, 53b, arcuate track gears 57a, 57b, rack gears 54a, 54b, and pinion gears 55a, 55b.

[0029] First, the nozzle moving mechanism 51a provided on the left arm portion 4a will be described with reference to FIGS.

[0030] As shown in Figures 4 and 5, the guide member 52a is provided at a location further outward in the left-right direction than the grindstone 10a. A plate-shaped member 43a is fixed to the end face of the gripping portion 40a of the arm portion 4a at the center in the left-right direction, and the guide member 52a is provided on the end face of the plate-shaped member 43a at the center in the left-right direction. As shown in Figure 7, the guide member 52a is a member shaped to describe an arc around the rotation shaft 31a of the spindle motor 30a, and the center of the arc coincides with the rotation center of the rotation shaft 31a. The radius of the arc of the guide member 52a is larger than the radius of the grindstone 10a.

[0031] The guide member 52a moves on an arcuate path Aa (see FIGS. 6, 7, etc.) around the rotation axis 31a of the grinding wheel 10a. The guide member 52a moves mainly above the rotation axis 31a of the grinding wheel 10a. The arcuate path Aa has the same radius and center position as the guide member 52a. The arcuate path Aa is not an actual member such as a rail, but is the movement path of the guide member 52a.

[0032] A plurality of guide members 53a are used to move the guide member 52a along the arcuate path Aa. As shown in FIGS. 4 and 5, the guide member 53a is a rotating member that protrudes toward the center in the left-right direction from the plate-shaped member 43a and can rotate around a left-right rotation axis. The guide member 53a is, for example, a bearing, and the outer ring of the bearing is rotatable. A plurality of guide members 53a are provided on the plate-shaped member 43a and support the guide member 52a by sandwiching it from the radially inner side and the radially outer side of the grinding wheel. The guide member 52a moves along the arcuate path Aa while being supported and guided by the rotating guide members 53a.

[0033] Although not shown, it is preferable that the shapes of the guide members 53a and 52a are devised so that the guide member 52a does not move toward the center in the left-right direction relative to the guide member 53a and fall off.

[0034] A nozzle holding member 56a is provided at the front portion (on the wafer holder 2 side) of the guide member 52a, and an arcuate track gear 57a is provided at the rear portion. The location where the nozzle holding member 56a is provided is also the end of the guide member 52a on the side facing the rotation direction of the grindstone 10a. The location where the arcuate track gear 57a is provided is also the side of the guide member 52a opposite the rotation direction of the grindstone 10a. The nozzle holding member 56a and the arcuate track gear 57a are provided on the surface of the guide member 52a on the center side in the left-right direction (on the grindstone 10a side).

[0035] The nozzle holding member 56a is provided with an inlet 58 through which grinding fluid sent from a location distant from the arm portion 4a is introduced, a nozzle 50a that discharges the grinding fluid, and a flow path for the grinding fluid from the inlet 58 to the nozzle 50a (not shown because it is inside the nozzle holding member 56a). As can be seen from FIG. 6 and other figures, the nozzle 50a is located radially outward of the outer circumferential surface of the grinding wheel 10a. The discharge port of the grinding fluid from the nozzle 50a faces the outer circumferential surface of the grinding wheel 10a. The nozzle 50a is also located further in the rotational direction of the grinding wheel 10a than the guide member 52a.

[0036] The radial direction of the disk-shaped grinding wheels 10a and 10b is referred to as the "grinding wheel radial direction," the side of the rotation axes 31a and 31b of the grinding wheels 10a and 10b is referred to as the "grinding wheel radial inner side," and the side away from the grinding wheels 10a and 10b is referred to as the "grinding wheel radial outer side."

[0037] As shown in Fig. 7, the nozzle holder 56a is provided with a threaded hole 59 that is closer to the nozzle 50a and an elongated hole 60 that is farther from the nozzle 50a as holes that penetrate the nozzle holder 56a in the left-right direction. The elongated hole 60 has an arc shape with the threaded hole 59 as its center and extends long in the radial direction of the grinding wheel 10a.

[0038] Although not shown, two screw holes are formed in the surface of the guide member 52a at the center in the left-right direction. One screw 61 (see FIG. 6) is screwed into the screw hole 59 of the nozzle holding member 56a and the first screw hole of the guide member 52a, and one screw 61 is screwed into the elongated hole 60 of the nozzle holding member 56a and the second screw hole of the guide member 52a, thereby fixing the nozzle holding member 56a to the guide member 52a. This fixation fixes the direction in which the grinding fluid is discharged from the nozzle 50a relative to the extension direction of the guide member 52a (extension direction of the arcuate orbit Aa).

[0039] The attachment angle of the nozzle holder 56a to the guide member 52a can be changed by changing the location of the screw 61 in the elongated hole 60 of the nozzle holder 56a, which in turn changes the direction in which the grinding fluid is discharged from the nozzle 50a relative to the extension direction of the guide member 52a (extension direction of the arcuate trajectory Aa).

[0040] The arcuate track gear 57a is fixed to the guide member 52a with screws (not shown). As shown in FIG. 6, the arcuate track gear 57a is an arc-shaped member with the same radius as the guide member 52a. Spur gear teeth are formed on the surface of the arcuate track gear 57a radially outward from the grinding wheel. The arcuate track gear 57a is connected to the arm portion 4a via the plate-shaped member 43a and the guide member 52a, and therefore moves integrally with the arm portion 4a in the same direction as the arm portion 4a moves up and down.

[0041] As shown in Figures 5 and 6, the rack gear 54a extends in the vertical direction at a location rearward of the grinding wheel 10a and the arcuate track gear 57a. The rack gear 54a is provided by, for example, being fixed to the floor or a rear structure, and is separate and independent from the arm unit 4a. Therefore, even if the arm unit 4a moves, the rack gear 54a does not move. A plurality of teeth are formed on the surface of the rack gear 54a facing the grinding wheel 10a.

[0042] The pinion gear 55a is a spur gear. The pinion gear 55a is provided on a rotation shaft 62 (see FIG. 4) that extends from the arm portion 4a toward the center in the left-right direction, and can rotate around the rotation shaft 62. When the arm portion 4a moves up and down, the pinion gear 55a also moves in the same direction as the arm portion 4a.

[0043] The pinion gear 55a meshes with the rack gear 54a at its rear and with the arcuate track gear 57a at its front. Therefore, when the arm unit 4a moves up and down, the pinion gear 55a rotates and moves up and down along the rack gear 54a, and the arcuate track gear 57a meshing with the pinion gear 55a moves along the arcuate track Aa, and the guide member 52a moves along the arcuate track Aa together with the arcuate track gear 57a. As the guide member 52a moves along the arcuate track Aa, the nozzle 50a provided on the guide member 52a moves along the arcuate track Aa, and the direction in which the grinding fluid is discharged from the nozzle 50a changes.

[0044] In this way, the driving force that changes the vertical position of the arm portion 4a is transmitted to a nozzle moving mechanism 51a consisting of a rack gear 54a, a pinion gear 55a, an arcuate track gear 57a, etc., thereby changing the position of the nozzle 50a and the direction in which the grinding fluid is discharged from the nozzle 50a.

[0045] The nozzle 50a moves at a location forward of the rotation axis 31a of the grinding wheel 10a. The direction in which the grinding fluid is discharged from the nozzle 50a is inclined backward and downward with respect to the horizontal direction. As the nozzle 50a moves along the arcuate trajectory Aa, the angle of inclination of the discharge direction from the nozzle 50a with respect to the horizontal direction changes.

[0046] The meshing structure of the three gears, the rack gear 54a, the pinion gear 55a, and the arcuate orbit gear 57a, correlates the movement direction of the arm unit 4a with the movement direction of the nozzle 50a. Specifically, as will be described later, when the arm unit 4a rises, the nozzle 50a moves in the rotation direction of the grinding wheel 10a.

[0047] Next, the nozzle moving mechanism 51b provided on the right arm portion 4b will be described.

[0048] 8, the nozzle movement mechanism 51b on the right side also includes a guide member 52b, a guide member 53b, an arcuate track gear 57b, a rack gear 54b, and a pinion gear 55b. As with the left side, the guide member 52b is supported by a guide member 53b provided on a plate-shaped member 43b and is movable along the arcuate track Ab.

[0049] The main differences between the right and left sides of the grinding fluid discharge devices 5a and 5b are as follows: First, in the left-side nozzle movement mechanism 51a, the guide member 52a moves mainly above the rotation axis 31b of the grinding wheel 10b, whereas in the right-side nozzle movement mechanism 51b, the guide member 52b moves mainly below the rotation axis 31b of the grinding wheel 10b. Also, in the left-side grinding fluid discharge device 5a, the nozzle 50a discharges the grinding fluid obliquely downward, whereas in the right-side grinding fluid discharge device 5b, the nozzle 50b discharges the grinding fluid obliquely upward. In addition, in the left-side nozzle movement mechanism 51a, the nozzle 50a is provided at a position farther than the guide member 52a in the direction of movement of the guide member 52a when the arm unit 4a is raised, whereas in the right-side nozzle movement mechanism 51b, the nozzle 50b is provided at a position farther than the guide member 52b in the direction of movement of the guide member 52b when the arm unit 4b is lowered (Note that the nozzles 50a, 50b are provided at positions farther than the guide members 52a, 52b in the direction of rotation of the grindstones 10a, 10b on both the left and right sides.) In addition, on the left side, when the arm unit 4a is raised, the nozzle 50a moves in the direction of rotation of the grindstone 10a, whereas on the right side, when the arm unit 4b is lowered, the nozzle 50b moves in the direction of rotation of the grindstone 10b.

[0050] The start and stop of the discharge of the grinding fluid from the left and right nozzles 50a, 50b is controlled by a grinding fluid discharge control device 63.

[0051] The processing apparatus 1 is provided with a control unit 7. As shown in Fig. 9, the control unit 7 is connected to spindle motors 30a, 30b, a moving mechanism 20, a suction device 23, a stage rotation device 22, a vertical movement device 41, a grinding fluid discharge control device 63, etc. The control unit 7 processes the peripheral portion of the wafer W by controlling the connected devices, etc.

[0052] Next, processing in the processing device 1 of this embodiment will be described.

[0053] When the peripheral edge of the wafer W is processed in the processing apparatus 1 configured as described above, the wafer W is first placed on the stage 21 of the wafer holder 2 and held by suction. At this time, the center of the wafer W coincides with the center of rotation of the stage 21, and the peripheral edge of the wafer W is located radially outward from the stage 21, as shown in Fig. 1. Also, at this time, the wafer holder 2 is separated from the arm portions 4a and 4b, as shown in Fig. 1.

[0054] Next, the control unit 7 controls the vertical movement device 41 to move the left and right arm units 4a, 4b up and down, thereby setting the left and right grinding wheels 10a, 10b to predetermined heights. The control unit 7 also controls the spindle motors 30a, 30b of the rotation drive units 3a, 3b to rotate the left and right grinding wheels 10a, 10b. The control unit 7 also controls the stage rotation device 22 to rotate the stage 21 of the wafer holder 2, thereby rotating the wafer W held by suction on the stage 21.

[0055] Next, the control unit 7 controls the movement mechanism 20 to move the wafer holder 2, so that the wafer W held and rotating by the wafer holder 2 comes into contact with the outer circumferential surfaces of the left and right grinding wheels 10a, 10b, which are gripped and rotated by the arm units 4a, 4b. The control unit 7 then controls the contact positions of the grinding wheels 10a, 10b on the wafer W while simultaneously bringing the left and right grinding wheels 10a, 10b into contact with the wafer W, thereby processing the entire peripheral edge of the wafer W into the shape shown in FIG.

[0056] Specifically, when processing the peripheral end surface Wb of the wafer W, the left and right grindstones 10a and 10b are arranged at the same height as shown in FIG.

[0057] On the other hand, when processing the area radially inward of the peripheral end surface Wb of the wafer, the left grinding wheel 10a is positioned on top and the right grinding wheel 10b is positioned on the bottom, as shown in Fig. 11. The wafer W is sandwiched between the left and right grinding wheels 10a and 10b from above and below, with the left grinding wheel 10a processing the top surface W1 of the wafer W and, simultaneously and in parallel, the right grinding wheel 10b processing the bottom surface W2 of the wafer W. As shown in Fig. 3, the peripheral edge of the wafer W is thicker toward the inside in the wafer radial direction, so as the processing position moves toward the inside in the wafer radial direction, the left grinding wheel 10a moves up and the right grinding wheel 10b moves down. The control unit 7 continues to rotate the left and right grinding wheels 10a, 10b and the wafer W while gradually changing the contact positions between the left and right grinding wheels 10a, 10b and the wafer W, thereby shaping the peripheral portion of the wafer W into a shape having an upper inclined surface Wa1, an upper arcuate surface Wc1, a lower inclined surface Wa2, and a lower arcuate surface Wc2 as shown in Figure 3.

[0058] While the left and right grinding wheels 10a, 10b are in contact with and processing the peripheral edge of the wafer W, grinding fluid is discharged from the nozzles 50a, 50b. As the processing position of the wafer W moves toward the inside in the wafer radial direction, the left and right grinding wheels 10a, 10b move up and down, and the position of the nozzles 50a, 50b and the direction of discharge of the grinding fluid from the nozzles 50a, 50b change due to the action of the nozzle moving mechanisms 51a, 51b. Specifically, the position and discharge direction of the nozzles 50a, 50b change so that the grinding fluid is always applied to the contact position between the grinding wheels 10a, 10b and the wafer W from a direction tangential to the grinding wheels 10a, 10b at the contact position or a direction close to that.

[0059] As a specific example of such a change, we will explain the changes in the position and discharge direction of the nozzles 50a, 50b when the contact position between the grinding wheels 10a, 10b and the wafer W moves radially inward of the wafer, the left arm 4a rises, and the right arm 4b descends. The movement directions of each component during this change are indicated by black arrows in Figures 6, 8, and 11. The discharge direction of the grinding fluid is also indicated by white arrows in Figures 10 and 11.

[0060] On the left side, when the arm 4a rises, the pinion gear 55a rotates and rises between the arcuate track gear 57a and the rack gear 54a. At the same time, the arcuate track gear 57a and the guide member 52a move along the arcuate track Aa in the rotational direction of the grinding wheel 10a on the left side. As the guide member 52a moves, the nozzle 50a, which is fixed in position relative to the guide member 52a, also moves along the arcuate track Aa in the rotational direction of the grinding wheel 10a. This movement causes the nozzle 50a to be positioned further forward and lower than before the movement. Furthermore, as the nozzle 50a moves, the direction in which the grinding fluid is discharged from the nozzle 50a also changes, and the angle of the discharge direction relative to the horizontal becomes smaller than before the movement.

[0061] Also, on the right side, when the arm portion 4b descends, the pinion gear 55b rotates and descends between the arcuate track gear 57b and the rack gear 54b. At the same time, the arcuate track gear 57b and the guide member 52b move along the arcuate track Ab in the rotational direction of the grinding wheel 10b on the right side. As the guide member 52b moves, the nozzle 50b, which is fixed in position relative to the guide member 52b, also moves along the arcuate track Ab in the rotational direction of the grinding wheel 10b. This movement causes the nozzle 50b to be positioned further forward and upward than before the movement. Furthermore, as the nozzle 50b moves, the direction in which the grinding fluid is discharged from the nozzle 50b also changes, and the angle of the discharge direction relative to the horizontal becomes smaller than before the movement.

[0062] When the left arm 4a descends and the right arm 4b ascends, the positions and discharge directions of the nozzles 50a and 50b change due to the action of the pinion gears 55a and 55b, the arcuate orbital gears 57a and 57b, etc. Specifically, the nozzles 50a and 50b move in the direction opposite to the rotation direction of the grinding wheels 10a and 10b, and the angle of inclination of the discharge direction of the grinding fluid from the nozzles 50a and 50b relative to the horizontal increases.

[0063] In this way, on both the left and right sides, the arm units 4a, 4b move up and down, thereby moving the contact positions between the grinding wheels 10a, 10b and the wafer W in the up and down direction, and the positions and discharge directions of the nozzles 50a, 50b change automatically in conjunction with the up and down movement of the arm units 4a, 4b. As a result, on both the left and right sides, the positions and discharge directions of the nozzles 50a, 50b change depending on the contact positions between the grinding wheels 10a, 10b and the wafer W, and the grinding fluid is always sprayed onto the contact positions between the grinding wheels 10a, 10b and the wafer W or the surrounding areas from a direction close to the tangential direction of the grinding wheels 10a, 10b at the contact positions.

[0064] When the processing of the peripheral edge of the wafer W is completed, the control unit 7 controls the movement mechanism 20 to move the wafer holder 2, and the wafer W held by the wafer holder 2 is separated from the grinding wheels 10a, 10b held by the arm units 4a, 4b. The wafer W is then removed from the wafer holder 2. The wafer W is then subjected to cleaning, drying, inspection, and the like.

[0065] Incidentally, the grinding wheels 10a, 10b wear and their radii become smaller as they are used for a longer period of time, and therefore, even if the positions of the nozzles 50a, 50b remain the same, the optimum direction in which the grinding fluid should be discharged from the nozzles 50a, 50b (the direction of the contact position between the grinding wheels 10a, 10b and the wafer W as seen from the nozzles 50a, 50b) changes as the grinding wheels 10a, 10b are used for a longer period of time. However, it is time-consuming and undesirable for an operator to change the attachment angle of the nozzle holder member 56a to the guide members 52a, 52b to change the discharge direction from the nozzles 50a, 50b every time the radius of the grinding wheels 10a, 10b changes to some extent.

[0066] Therefore, it is preferable that the operator adjust the attachment angle of the nozzle holder 56a to the guide members 52a, 52b so that the grinding fluid is applied to the contact position between the grinding wheels 10a, 10b and the wafer W when the grinding wheels 10a, 10b have a radius intermediate between the expected maximum radius and the expected minimum radius and are attached to the rotation shafts 31a, 31b. This adjustment can be made by the operator changing the position through which the screw 61 passes in the elongated hole 60 of the nozzle holder 56a. Furthermore, the operator may adjust the spreading of the grinding fluid discharged from the nozzles 50a, 50b so that the grinding fluid continues to be applied to the contact position between the grinding wheels 10a, 10b and the wafer W even when the radius of the grinding wheels 10a, 10b changes.

[0067] Next, the effects of this embodiment will be described.

[0068] According to the processing apparatus 1 of this embodiment, the direction of the grinding fluid discharged from the nozzles 50a, 50b changes depending on the contact position between the grinding wheels 10a, 10b and the wafer W. Therefore, the grinding fluid can always be discharged aimed at the contact position between the grinding wheels 10a, 10b and the wafer W, thereby fully demonstrating the effect of the grinding fluid and improving the quality of the wafer W. Furthermore, since a sufficient amount of grinding fluid is applied to the grinding wheels 10a, 10b, the life of the grinding wheels 10a, 10b is extended. Furthermore, even if the contact position between the grinding wheels 10a, 10b and the wafer W changes, there is no need to take measures such as increasing the number of nozzles 50a, 50b that discharge the grinding fluid so that the grinding fluid is applied to the contact position as much as possible.

[0069] Furthermore, the arm sections 4a, 4b hold and move the grinding wheels 10a, 10b, and as the arm sections 4a, 4b move in the vertical direction, the contact positions in the vertical direction between the grinding wheels 10a, 10b and the wafer W also move. The grinding fluid discharge devices 5a, 5b have a structure that changes the discharge direction of the grinding fluid from the nozzles 50a, 50b depending on the vertical position of the arm sections 4a, 4b. Therefore, even if the contact positions between the grinding wheels 10a, 10b and the wafer W change, the grinding fluid can be automatically discharged targeting the contact positions.

[0070] In the grinding fluid discharge devices 5a and 5b, the nozzles 50a and 50b move along arcuate tracks Aa and Ab formed around the rotation axes 31a and 31b of the grinding wheels 10a and 10b. Therefore, the nozzles 50a and 50b can easily discharge the grinding fluid by targeting the contact positions between the grinding wheels 10a and 10b and the wafer W.

[0071] Furthermore, in the grinding fluid discharge devices 5a, 5b, the nozzles 50a, 50b are moved by using a driving force that changes the vertical position of the arm units 4a, 4b, thereby changing the direction of discharge of the grinding fluid. Therefore, there is no need to add a dedicated driving force for changing the direction of discharge from the nozzles 50a, 50b. Furthermore, since the vertical positions of the arm units 4a, 4b and the direction of discharge from the nozzles 50a, 50b are related to each other, the direction of discharge from the nozzles 50a, 50b can be reliably changed depending on the vertical positions of the arm units 4a, 4b.

[0072] Furthermore, nozzle movement mechanisms 51a and 51b for moving the nozzles 50a and 50b include guide members 52a and 52b, rack gears 54a and 54b, arcuate track gears 57a and 57b, and pinion gears 55a and 55b. The pinion gears 55a and 55b mesh with the rack gears 54a and 54b and the arcuate track gears 57a and 57b, respectively. The rack gears 54a and 54b extend in the vertical direction independently of the arm portions 4a and 4b. The arcuate track gears 57a and 57b are provided on the guide members 52a and 52b. Based on this structure, when the arm units 4a, 4b move up and down, the pinion gears 55a, 55b rotate while moving along the rack gears 54a, 54b, and the arcuate track gears 57a, 57b and guide members 52a, 52b move along the arcuate tracks Aa, Ab. As a result, the driving force that changes the up and down positions of the arm units 4a, 4b can be used to change the discharge direction of the grinding fluid from the nozzles 50a, 50b provided on the guide members 52a, 52b.

[0073] Furthermore, the attachment angle of the nozzle holder 56a equipped with the nozzles 50a and 50b to the guide members 52a and 52b can be changed, and by changing the attachment angle, the direction in which the grinding fluid is discharged from the nozzles 50a and 50b relative to the extension direction of the guide members 52a and 52b can be changed. Therefore, the operator can adjust the direction in which the grinding fluid is discharged.

[0074] Next, a modification of this embodiment will be described.

[0075] The structure, operation, arrangement, etc. of each part constituting the processing apparatus 1, such as the wafer holder 2 and the arm units 4a, 4b, may be different from those in the above embodiment. For example, the movement direction of the arm units 4a, 4b may be the thickness direction of the wafer W, and the movement direction of the arm units 4a, 4b may be a direction other than up and down depending on the orientation of the wafer W. If the movement direction of the arm units 4a, 4b is a first direction, the wafer holder 2 may move in a second direction different from the first direction, so long as it can bring the grinding wheels 10a, 10b and the wafer W into contact with and separate them from each other.

[0076] In the above embodiment, the wafer holder 2 that holds the wafer W moves in the front-to-rear direction to bring the grinding wheels 10a, 10b into contact with and separate from the wafer W. However, the arm units 4a, 4b that hold the grinding wheels 10a, 10b may also move in the front-to-rear direction. Alternatively, both the wafer holder 2 and the arm units 4a, 4b may move in the front-to-rear direction.

[0077] The left and right sides may be interchanged in the above-described processing apparatus 1. Specifically, the grinding wheels 10a and 10b on the left side may process the lower inclined surface Wa2 and the lower arcuate surface Wc2 of the wafer W, and the grinding wheels 10a and 10b on the right side may process the upper inclined surface Wa1 and the upper arcuate surface Wc1 of the wafer W, and the structures of the nozzle movement mechanisms 51a and 51b may also be interchanged.

[0078] In addition to the above, various modifications are possible without departing from the spirit of the present invention, and such modified forms are also considered to be included in the scope of the present invention. [Explanation of symbols]

[0079] Aa...circular orbit, Ab...circular orbit, W...wafer, W1...upper surface, W2...lower surface, Wa1...upper inclined surface, Wa2...lower inclined surface, Wb...peripheral end surface, Wc1...upper arc surface, Wc2...lower arc surface, 1...processing device, 2...wafer holder, 3a...rotation drive unit, 3b...rotation drive unit, 4a...arm unit, 4b...arm unit, 5a...grinding fluid discharge device, 5b...grinding fluid discharge device, 7...control unit, 10a...grinding wheel, 10b...grinding wheel, 20...movement mechanism, 21...stage, 22...stage rotation device, 23...suction device, 30a...spindle motor, 30b...spindle motor, 31a...rotation shaft, 31b...rotation Rotating shaft, 40a...gripping portion, 40b...gripping portion, 41...up-and-down movement device, 43a...plate-shaped member, 43b...plate-shaped member, 50a...nozzle, 50b...nozzle, 51a...nozzle moving mechanism, 51b...nozzle moving mechanism, 52a...guide member, 52b...guide member, 53a...guide member, 53b...guide member, 54a...rack gear, 54b...rack gear, 55a...pinion gear, 55b...pinion gear, 56a...nozzle holding member, 57a...circular orbit gear, 57b...circular orbit gear, 58...inlet, 59...screw hole, 60...long hole, 61...screw, 62...rotating shaft, 63...grinding fluid discharge control device

Claims

1. A processing device that processes and shapes a peripheral portion of a plate-shaped wafer having a predetermined thickness and a main surface perpendicular to the thickness direction by contacting the peripheral portion with a rotating grindstone, a wafer holder that holds the wafer; a rotation drive unit that holds the grindstone and rotates the grindstone about a rotation axis that extends parallel to the main surface of the wafer; an arm portion that holds the rotation drive portion and is movable in a first direction that is the thickness direction; a movement mechanism that can change the position of the arm portion relative to the wafer holder in a second direction different from the first direction, thereby bringing the grinding stone into contact with and separating the peripheral portion of the wafer; a grinding fluid discharge device provided on the arm portion and configured to discharge a grinding fluid during processing of the wafer; a nozzle provided in the grinding fluid discharge device and having a discharge port for the grinding fluid formed therein; The grinding fluid discharge device changes the discharge direction of the grinding fluid from the nozzle according to the contact position between the grindstone and the wafer so that the discharge direction is directed toward the contact position.

2. The processing apparatus according to claim 1 , wherein the grinding fluid discharge device changes the discharge direction from the nozzle to face the contact position in accordance with the position of the arm portion relative to the wafer holder in the first direction.

3. the grinding fluid discharge device includes a nozzle moving mechanism that moves the nozzle along an arcuate path formed around the rotation axis of the grindstone, The processing device according to claim 2 , wherein the nozzle changes the discharge direction to face the contact position by moving along the arcuate trajectory.

4. 4. The processing device according to claim 3, wherein a driving force for changing the position of the arm portion in the first direction relative to the wafer holding portion is transmitted to the nozzle moving mechanism, thereby moving the nozzle along the arcuate orbit and changing the discharge direction to face the contact position.

5. 5. The processing device according to claim 3, wherein the nozzle moving mechanism comprises a guide member that moves integrally with the nozzle on the arcuate track, and a guide member that guides the guide member to move on the arcuate track.

6. 6. The processing device of claim 5, wherein the nozzle movement mechanism comprises a rack gear that is independent of the arm portion and extends in the first direction, an arcuate track gear that is provided on the guide member, and a pinion gear that meshes with the rack gear and the arcuate track gear, and when the arm portion moves in the first direction, the pinion gear and the arcuate track gear rotate, causing the guide member to move on the arcuate track.

7. The processing device according to claim 5 , wherein the ejection direction from the nozzle relative to the predetermined direction of the guide member is changeable.

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