JP2016190284A - Manufacturing method of chamfered baseboard and chamfering device used in the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable helical grinding even if a processed material is rectangular or polygonal, to make surface roughness favorable, and to reduce the collapse of a shape.SOLUTION: In a manufacturing method of a chamfered baseboard which grinds an end face of a plate-shaped processed material W by a grinding groove 74 of an external periphery precision grinding wheel 72, a plane of the processed material W is adsorbed to a thickness direction by a chuck table 73 which is smaller than an external peripheral shape of the processed material W, a rotating shaft of the external periphery precision grinding wheel 72 is inclined to an axis in the thickness direction vertical to the plane of the processed material W, the grinding groove 74 is pressed against the end face of the processed material W from a vertical direction, and made to abut thereon, an end face upper part or a lower part of the processed material W is ground by the grinding groove 74, and after that, the external periphery precision grinding wheel 72 is relatively ascended or descended to the thickness direction with respect to the processed material W, and reground.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a highly accurate chamfered substrate manufacturing method and apparatus for various materials such as silicon, sapphire, compound, glass, etc., in particular, end surfaces of plate-like workpieces such as semiconductor wafers and glass panels. It is suitable for end face processing of a workpiece having a straight portion other than a circle.

  In recent years, there has been a strong demand for wafer quality improvement, and the processing state of the wafer end face (edge part) has been regarded as important, and semiconductor wafers such as silicon wafers used in the manufacture of semiconductor devices and the like prevent chipping due to handling. A chamfering process is performed by grinding the edge, and a mirror chamfering process is performed by polishing. That is, in the semiconductor manufacturing process, the quality improvement of the edge characteristics is an indispensable process from the wafer manufacturing to the device manufacturing.

  Silicon and other materials are hard and brittle, and if the edge of the wafer remains sharp during slicing, it can easily crack or chip during handling such as transport and alignment in subsequent processing steps, and fragments can damage or contaminate the wafer surface. Or In order to prevent this, the end face of the cut wafer is chamfered with a chamfering grindstone coated with diamond. At this time, the diameter of the outer periphery with variations is matched to match the width of the orientation flat (OF), and the size of a small notch called a notch is also matched.

  In addition, the glass substrates used in smartphones and tablets that are designed to be thinner and lighter are masked, formed with sensor electrodes, and then cut, resulting in chamfering processing quality, processing surface roughness, The occurrence of micro cracks directly affects the end face strength of the glass substrate.

  Further, in normal grinding, the chamfered portion is ground in a state where the main surface of the wafer W is perpendicular to the rotation axis of the resin grindstone. In this case, circumferential chamfering marks are likely to occur in the chamfered portion. Therefore, it is known to perform so-called helical grinding in which a chamfered portion of a wafer is ground by tilting a resin bond grindstone (resin grindstone) with respect to the wafer, for example.

  When the helical grinding is performed, not only the processing distortion of the chamfered portion is reduced as compared with the normal grinding, but also an effect that the contact area between the chamfered portion of the wafer and the grindstone is increased and the surface roughness of the chamfered portion is improved.

  Furthermore, when the chamfered portion of a semiconductor wafer is helically ground with a resin grindstone or the like, if the chamfered portion is continuously processed, the vertical angle of the groove of the resin grindstone gradually changes, resulting in a further vertical asymmetry of the chamfered portion of the wafer. growing. Therefore, the edge of the disc-shaped truer is ground with the groove of the first grindstone formed with the groove of the asymmetrical shape up and down to form the edge of the truer into the asymmetrical groove shape, and the second A groove is formed around the second whetstone by relatively tilting the whetstone, and a wafer is tilted relative to the groove direction by the second whetstone to obtain a substantially symmetrical resin whetstone, and chamfered. It is known to finely grind parts, and is described in Patent Document 1, for example.

  Further, in a chamfering method in which the rotation axis of the chamfering grindstone is inclined at a predetermined angle with respect to the rotation axis of the wafer, it is known to form a wafer outer peripheral portion and a processing groove for the OF portion on the outer peripheral grinding grindstone. It is described in Document 2.

  Furthermore, in order to make the chamfer width of the notch portion constant, it is known that the grindstone is relatively moved in the thickness direction of the wafer during chamfering, and is described in Patent Document 3.

JP 2007-165712 A JP 2007-21586 A JP 2005-153129 A

  In the above prior art, the one described in Patent Document 1 requires a first grindstone in which a groove having a vertically asymmetric shape is formed around it, and its shape is difficult to determine. In the case of a circular wafer, the same shape can be used for the entire circumference, so it can be determined uniquely, but it can be determined by using a wafer substrate with an OF, a rectangular or polygonal wafer with an arc at a corner, a substrate, a cover glass, etc. If there is a part and a non-circular part, it is not only more difficult, but also the change in the vertical angle of the groove of the resin grindstone becomes larger at the position where it moves from the circular part to the non-circular part, and the entire circumference is helically ground. It was extremely difficult to do. In other words, at the corner portion of the substrate (work) having a corner, one-side contact with only one of the upper surface and the lower surface of the grindstone groove occurred, and good chamfering could not be performed.

  The one described in Patent Document 2 is good when the grinding process is complicated and the main part is a circular part and the number of non-circular parts is small, but application is difficult in the case of a rectangle or a polygon.

  In the thing of patent document 3, since it must carry out, moving a grindstone relatively in the thickness direction of a wafer during chamfering, in order to raise the accuracy of chamfering, control of the thickness direction of a wafer or a grindstone is required. It was complicated and difficult.

  The object of the present invention is to solve the above-mentioned problems of the prior art, and even a wafer substrate with an OF (orientation flat), a rectangular or polygonal wafer, a substrate, a cover glass or the like having a circular portion and a non-circular portion is helical. The object is to make grinding easy and increase the contact area between the workpiece and the grindstone, to improve the surface roughness and to improve the shape collapse.

  In order to achieve the above object, the present invention provides a method for manufacturing a chamfered substrate in which an end surface of a plate-like workpiece is ground with a grinding groove of a grinding wheel, wherein the plane of the workpiece is in the thickness direction, Adsorbed by a chuck table smaller than the outer peripheral shape of the workpiece, tilting the rotation axis of the grinding wheel with respect to the axis in the thickness direction perpendicular to the plane of the workpiece, and grinding the grinding groove into the workpiece Pressing and contacting the end surface of the material from the vertical direction, grinding the upper or lower portion of the end surface of the workpiece with the grinding groove, and then the grinding wheel relative to the workpiece in the thickness direction Grind again by raising or lowering.

  In the above, it is preferable that the width of the grinding groove is larger than the apparent thickness of the workpiece when the rotation axis of the grinding wheel is tilted.

  Further, in the above, the upper part of the end face of the workpiece is ground with the grinding groove, and then the grinding wheel is raised in the thickness direction relative to the workpiece to be ground again, or It is preferable that the lower part of the end face of the workpiece is ground with the grinding groove, and then the grinding wheel is lowered relative to the workpiece in the thickness direction and is ground again.

  Further, in the above, the upper or lower part of the end face of the workpiece is ground so as to make one round with the grinding groove over the entire circumference, and then the grinding wheel is relatively moved with respect to the workpiece. It is preferable to perform one round grinding by raising or lowering in the thickness direction.

  Furthermore, in the above, it is preferable to tilt the rotation axis of the grinding wheel 3 to 15 °.

  Further, in the above, it is preferable that the processing of the end surface of the workpiece is performed by grinding the upper portion of the end surface of the workpiece, grinding the central portion, and grinding the lower portion, respectively.

  Furthermore, in the above, it is preferable that the grinding of the upper part, the grinding of the central part, and the grinding of the lower part are performed so as to make one round of the end face of the workpiece with the grinding groove over the entire circumference.

  Further, the present invention provides a chamfering device for chamfering an end surface of a plate-shaped workpiece with a grinding groove of a grinding wheel, and adsorbs a plane of the workpiece in the thickness direction, and the outer peripheral shape of the workpiece The grinding table which is also in contact with the smaller chuck table and the axis of rotation with respect to the axis in the thickness direction perpendicular to the plane of the workpiece and pressing the grinding groove against the end face of the workpiece from the perpendicular direction Grinding the upper or lower part of the end face of the workpiece with the grinding groove, and then raising or lowering the grinding wheel relative to the workpiece in the thickness direction. Grind again.

  Furthermore, in the above, it is preferable that the width of the grinding groove is larger than the apparent thickness of the workpiece when the rotation axis of the grinding wheel is tilted.

  Further, in the above, the upper part of the end face of the workpiece is ground with the grinding groove, and then the grinding wheel is raised relative to the workpiece in the thickness direction and is ground again. Alternatively, it is preferable that the lower part of the end face of the workpiece is ground with the grinding groove, and then the grinding wheel is lowered relative to the workpiece in the thickness direction and is ground again.

  Further, in the above, the upper or lower part of the end face of the workpiece is ground so as to make one round with the grinding groove over the entire circumference, and then the grinding wheel is relatively relative to the workpiece. Further, it is preferable to perform one round grinding by raising or lowering in the thickness direction.

  Furthermore, in the above, it is preferable that the rotation axis of the grinding wheel is inclined by 3 to 15 °.

  Furthermore, in the above-mentioned thing, it is preferable that the processing of the end surface of the workpiece is performed by grinding the upper portion of the end surface, grinding the central portion, and grinding the lower portion.

  According to the present invention, even a rectangular or polygonal workpiece can be subjected to helical grinding, the surface roughness can be improved, and the shape collapse can be reduced.

The top view which shows the principal part of the chamfering apparatus which concerns on one Embodiment of this invention. The perspective view which shows the structure of the process part in one Embodiment. (Work material is circular and straight part) The top view in FIG. The perspective view which shows the structure of the process part in one Embodiment. (Work material is mainly straight part) The top view in FIG. The side view which shows the relationship between the grinding groove | channel and workpiece in one Embodiment. (Top surface processing) The side view which shows the relationship between the grinding groove | channel and workpiece in one Embodiment. (Processing of the bottom surface) The top view explaining contact | abutting with a workpiece and the upper-lower-end part of a grinding wheel. The perspective view which shows the helical grinding of the end surface processing of the conventional board | plate material. The side view explaining the difference between the conventional grinding and grinding by one embodiment. The side view which shows the end surface of the workpiece processed by the manufacturing method of the chamfer board | substrate by one Embodiment. The side view which shows the procedure of the manufacturing method of the chamfer board | substrate by other embodiment. The side view which shows the detail of the grinding wheel and workpiece which concern on embodiment of this invention.

  Embodiments of the present invention will be described below in detail with reference to the drawings. The invention is not limited to the embodiments, and constituent elements in the embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

  FIG. 1 is a plan view showing a main part of a chamfering apparatus according to an embodiment of the present invention. The chamfering apparatus mainly includes a supply / recovery unit 20 and a processing unit 10, and includes a pre-alignment unit, a cleaning unit, a post-measurement unit, a transport unit, and the like, although not shown.

  The wafer processing step is performed in the order of slicing → chamfering → lapping → etching → donor killer → fine chamfering, and various cleanings are used to remove dirt between the processes. Silicon and other materials are hard and brittle, and if the edge of the wafer remains sharp during slicing, it can easily crack or chip during handling such as transport and alignment in subsequent processing steps, and fragments can damage or contaminate the wafer surface. Or In order to prevent this, in the chamfering process, the end surface of the cut wafer is chamfered with a chamfering grindstone coated with diamond.

  The chamfering process may be performed after the lapping process. At this time, the diameter of the outer periphery with variations is matched, the length of the width of the orientation flat (OF) is matched, and the size of a small notch called a notch is also matched.

  The supply / recovery unit 20 supplies the wafer W to be chamfered from the wafer cassette 30 to the processing unit 10 and collects the chamfered wafer to the wafer cassette 30. This operation is performed by the supply / recovery robot 40. The wafer cassette 30 is set on a cassette table 31 and stores a number of wafers W to be chamfered. The supply / recovery robot 40 takes out the wafers W one by one from the wafer cassette 30 and stores the chamfered wafers in the wafer cassette 30.

  The supply / recovery robot 40 includes a three-axis rotation type transfer arm 50, and the transfer arm 50 includes a suction pad (not shown) on an upper surface thereof. The transfer arm 50 holds the wafer W by vacuum suction of the back surface of the wafer W with a suction pad. That is, the transfer arm 50 of the supply / recovery robot 40 can move up and down, move up and down, and turn while holding the wafer W, and the wafer W is transferred by combining these operations.

  The processing unit 10 is disposed in the front portion of the wafer chamfering apparatus, and performs all processing of the outer peripheral chamfering of the wafer W, that is, roughing to finishing. The processing unit 10 includes a wafer feeding device 60, an outer periphery rough grinding device 62, a transfer arm 63 that conveys the wafer W, and an outer periphery fine grinding device 61.

  FIG. 2 is a perspective view showing the configuration of the processing unit 10, FIG. 3 is a plan view, and the wafer feeding device 60 has a chuck table (wafer table) 66 that holds the wafer W by suction. The chuck table 66 is driven by driving means (not shown) to move in the front-rear direction (Y-axis direction), the left-right direction (X-axis direction), and the vertical direction (Z-axis direction). By being driven by the table drive motor 65, it rotates around the central axis (θ axis).

  The outer peripheral rough grinding device 62 is disposed at a position separated from the chuck table 66 of the wafer feeding device 60 by a predetermined distance in the Y-axis direction. This outer peripheral rough grinding device 62 has an outer peripheral rough grinding spindle 68 that is driven by an outer peripheral rough grinding motor 67 to rotate. The outer periphery roughing spindle 68 is configured to be movable in the front-rear direction (Y-axis direction) and the vertical direction (Z-axis direction) by being driven by a driving unit (not shown).

  A peripheral rough grinding spindle 69 for roughing (rough grinding) the outer periphery of the wafer W is mounted on the peripheral rough grinding spindle 68, and serves as a rotation axis thereof. The outer peripheral rough grinding wheel 69 has a plurality of outer peripheral rough grinding grooves formed on the outer peripheral surface thereof (general shape grindstone). By pressing the outer periphery of the wafer W against this groove, the outer periphery of the wafer W is roughened ( Rough grinding).

  The peripheral grinding device 61 is disposed at a position away from the chuck table 66 of the wafer feeding device 60 by a predetermined distance in the X-axis direction. The outer peripheral fine grinding device 61 has an outer peripheral fine grinding spindle 71 that is driven by the outer peripheral fine grinding motor 70 to rotate. The outer peripheral precision spindle 71 is configured to be movable in the left and right direction (X-axis direction) and the vertical direction (Z-axis direction) by being driven by a driving means (not shown). The outer peripheral fine grinding spindle 71 is equipped with an outer peripheral fine grinding wheel 72 for finishing the outer periphery of the wafer W (fine grinding), and serves as a rotating shaft thereof.

  The peripheral grinding wheel 72 has a circumferential grinding groove formed on its outer peripheral surface (total grinding wheel), and the outer circumference of the wafer W is finished by pressing the outer circumference of the wafer W against this groove.

  At this time, the wafer is subjected to helical grinding performed by tilting the rotation axis of the outer peripheral fine spindle 71 with respect to the rotation axis of the chuck table 66 in the tangential direction of the outer periphery of the wafer W by 3 to 15 °, preferably 6 to 10 °. Finish the outer chamfering of W.

  As a result, the movement direction of the abrasive grains intersects with the movement direction of the outer periphery of the wafer W, the contact area increases, etc., so that the wear of the grinding wheel is suppressed and the shape deformation of the outer periphery can be reduced. As a result, the roughness of the processed surface (grind surface) is improved.

  Next, the operation of the processing unit 10 will be described. In the standby state before the start of processing, the wafer W held on the chuck table 66 is arranged so that the center thereof coincides with the rotation axis of the chuck table 66. At this time, the OF portion of the wafer W is disposed so as to face a predetermined direction (in this example, the Y-axis direction).

  Further, the outer peripheral rough grinding wheel 69 and the outer peripheral fine grinding wheel 72 are located at positions away from the wafer W by a predetermined distance. Specifically, the rotation center of the outer peripheral rough grinding wheel 69 is disposed at a position separated from the rotation center of the wafer W by a predetermined distance in the Y-axis direction, and the rotation center of the outer peripheral grinding wheel 72 is relative to the wafer W. It is arranged at a position separated by a predetermined distance in the X-axis direction.

  First, an alignment operation is performed. In this alignment operation, the relative positional relationship between the wafer W held on the chuck table 66, the outer peripheral rough grinding wheel 69, and the outer peripheral fine grinding wheel 72 in the vertical direction (Z-axis direction) is adjusted.

  When the alignment operation is completed, the outer periphery roughing motor 67 is driven. Next, grinding (rough machining) by the outer periphery rough grinding wheel 69 is started. Specifically, a Y-axis motor (not shown) of the outer peripheral rough grinding device 62 is driven, and the outer peripheral rough grinding spindle 68 is fed toward the chuck table 66 along the Y-axis direction.

  As the outer peripheral rough grinding grindstone 69, for example, a diamond bond metal bond grindstone having a diameter of 202 mm and having a particle size of # 800 can be used. The outer periphery roughing spindle 68 is a built-in motor driven spindle using a ball bearing, and is rotated at a predetermined rotational speed, for example, a rotational speed of 8,000 rpm.

  When the outer periphery roughing spindle 68 is fed toward the chuck table 66, the outer periphery of the wafer W comes into contact with the outer peripheral rough grinding grinding groove formed on the outer peripheral rough grinding wheel 69, and the outer periphery of the wafer W is outer peripheral rough grinding. After being ground by the grindstone 69, rough machining of the outer peripheral chamfer of the wafer W is started.

  Since the wafer W in FIG. 2 is initially circular after the rough machining by the outer peripheral rough grinding wheel 69 is started, the wafer W held on the chuck table 66 starts to rotate in the arrow direction at a constant speed. When this rotational angle, that is, the OF portion where the machining point is a straight line portion, the feed amount in the direction toward the chuck table 66 in the Y direction is increased, and the outer periphery spindle 68 is moved in the X direction. Move the straight line in the direction to process the straight part. Thereafter, when the processing of the linear portion is finished, the plate-like wafer W held on the chuck table 66 is rotated again in the direction of the arrow at a constant speed, the remaining circular portion is ground, and rough processing by the outer peripheral rough grinding wheel 69 is performed. Exit.

  Next, the finishing process by the outer peripheral grinding wheel 72 is performed in the same manner. As the outer peripheral grinding wheel 72, a resin bond grinding wheel of diamond abrasive grains is suitable. Further, the outer circumferential chamfering of the wafer W is performed with the rotation axis of the outer peripheral fine spindle 71 inclined at 3 to 15 °, preferably 6 to 10 °, in the tangential direction of the outer periphery of the wafer W with respect to the rotation axis of the chuck table 66. Finishing is performed.

  Furthermore, the chamfering groove of the outer peripheral grinding wheel 72 is formed by a truer, but detailed description thereof is omitted. Further, as the outer peripheral rough grinding grindstone 69, for example, a material which is mainly composed of metal powder such as Fe, Cr, Cu or the like and mixed with diamond abrasive grains is used. As the material of the truer, a material which can be processed by the outer peripheral rough grinding wheel 69 and can grind the outer peripheral grinding wheel 72 is adopted.

  For example, it is desirable that abrasive grains made of silicon carbide be bonded with a phenol resin with a filler or the like if necessary, and molded into a disk-shaped truer. As the material of the outer peripheral fine grinding stone 72, a material capable of finely grinding a chamfered portion such as a silicon wafer by the formed polishing while the grinding groove 74 can be formed around by grinding with a truer. For example, it is desirable to use a material mainly composed of phenol resin, epoxy resin, polyimide resin, polystyrene resin or polyethylene resin, and formed by mixing diamond abrasive grains or cubic boron nitride abrasive grains.

  Further, as the peripheral fine grinding stone 72, for example, a resin bond grindstone of diamond abrasive grains having a diameter of 50 mm and having a grain size of # 3000 is used. The outer peripheral precision spindle 71 is a built-in motor driven spindle using an air bearing and is rotated at a rotational speed of 35,000 rpm.

  FIG. 4 is a perspective view showing a configuration of a processing portion when the workpiece is not circular but rectangular, and FIG. 5 is a plan view similarly. When the workpiece is not a circle but a rectangle, as shown in FIGS.

  As smartphones and tablets become thinner and lighter, glass substrates, cover glass, sapphire, and ceramics are used on the surface, and end face strength is important. In mirror grinding, chipping suppression and good surface roughness are achieved. Is required. Chamfering processing quality, processing surface roughness, microcracking, etc. directly affect the end face strength of the glass substrate.

  4 and 5 show chamfering processing of a rectangular glass panel in a smartphone or tablet. An X-axis motor (not shown) of the outer peripheral grinding device 61 is driven, and the outer peripheral fine spindle 71 moves along the X-axis direction. It is sent toward the chuck table 73.

  When the outer periphery precision spindle 71 is sent toward the chuck table 73, the straight portion of the glass panel (or wafer) W comes into contact with the outer periphery fine grinding groove, which is a chamfering groove formed in the outer periphery fine grinding wheel 72. The outer peripheral part of the glass panel W is helically ground by the outer peripheral grinding wheel 72, and the processing of the outer peripheral chamfering of the glass panel W is started. After the processing by the outer peripheral grinding wheel 72 is started, the glass panel W of FIGS. 4 and 5 is rectangular, and thus the glass panel W held on the chuck table 73 starts moving at a constant speed in the Y-axis direction. When the processing point reaches the corner portion, the chuck table 73 moves in the Y-axis direction while rotating 90 ° to process the next linear portion. Hereinafter, the entire outer periphery of the glass panel W is processed similarly.

  In addition, the grinding wheel is made of a chamfering wheel material having a porous surface and a lubricant together with a saturated fatty acid solution, and the surface is dried to form a lubricant-impregnated grinding wheel. It is desirable to do. Thereby, the lubricant can be reliably supplied to the cutting point of the grindstone, and the cutting point temperature can be set to a predetermined temperature or lower. Moreover, since the coolant is water, it is possible to prevent environmental pollution due to the coolant. Furthermore, in the wafer chamfering apparatus, since the grindstone is impregnated with the lubricant, the lubricant can be supplied to the cutting point over a long period of time, and the coolant is water, so that processing can be performed at low temperature and in consideration of the environment.

  The chuck table 73 has a shape similar to that of the rectangular glass panel W as shown in FIG. 5, but is more than the glass panel W so that the glass panel W itself is slightly elastically deformed when processed by the peripheral grinding wheel 72. The glass panel W becomes sufficiently small, and is held overhanging from the chuck table 73.

  Specifically, the size of the chuck table 73 is Q = (1) where Q is the distance from the center of the glass panel W in the X-axis direction and P is the distance from the center of the chuck table 73 in the X-axis direction. .3 to 1.7) P, more preferably, Q = 1.5P is preferable from the viewpoint of fixing and grinding by adsorption of the glass panel W. That is, while avoiding the influence on processing accuracy such as deformation, bending, and distortion of the glass panel W, the workpiece, the glass panel W itself is slightly elastically deformed during processing, and the outer peripheral grinding wheel 72 is a soft resin bond wheel. Combined with this, it reduces the impact of such vibration. The same applies to the Y-axis direction, and it is desirable to set N = (1.3 to 1.7) H in FIG. 5, more preferably N = 1.5H. That is, the shape of the chuck table 73 is smaller than the outer peripheral shape of the workpiece, and is preferably 0.6 to 0.8 times larger than the planar shape of the glass panel W in both length and width. The rectangular glass panel W is preferably about 120 mm × 60 mm in length and width and about 0.5 to 1.5 mm in thickness, and the rectangular chuck table 73 is preferably about 80 mm × 40 mm.

  Since the rotation axis of the outer peripheral fine spindle 71 is inclined with respect to the chuck table 73 in the tangential direction of the outer periphery of the glass panel W by θ = 3 to 15 °, preferably 6 to 10 °, the glass panel W is subjected to the outer peripheral fine grinding. The grinding groove 74 of the grindstone 72 abuts at this angle θ, and the movement direction of the abrasive grains intersects with the movement direction of the glass panel W. Further, if the inclination angle is too large, it is not preferable in terms of increase in grinding resistance, chipping of upper and lower corners on the end face, scratches, and the like.

  FIG. 6 is a side view showing the relationship between the grinding groove 74 of the peripheral grinding wheel 72 and the workpiece W. As shown in FIG. When the grinding groove 74 of the grinding wheel 72 is inclined at an angle θ, the lower surface of the workpiece W comes closest to the lower end of the grinding groove 74 from the position where the upper end of the grinding groove 74 contacts the upper surface of the workpiece W. The distance to the non-contact position, that is, the apparent thickness of the workpiece when the grinding groove 74 is inclined by the angle θ, is larger than the dimension y0 from the right end to the left end in FIG. 6, and y> y0. y0 is approximately Dtan θ + t / cos θ, where D is the diameter of the grinding groove 74 and t is the thickness of the workpiece W. The method of widening the width of the grinding groove 74 may be to widen the transfer groove when tooling in advance, or the grinding groove 74 may be processed widely by moving the tooling tool up and down in the Z-axis direction. May be.

Next, the processing procedure of helical grinding will be described below.
FIG. 6 is a side view showing a state in which the upper surface of the glass panel W is being processed. When the outer peripheral precision spindle 71 is fed toward the chuck table 73, the upper surface slope 72u at the upper right end of the grinding groove 74 is shown. The upper surface of the glass panel W, the upper right end portion in FIG. 6 abuts, and processing starts, and then the glass panel W held on the chuck table 73 moves at a constant speed in the Y-axis direction to perform chamfering.

  Since the grinding groove 74 is wider than the apparent thickness of the glass panel W, the lower surface of the glass panel W does not contact. The central portion and the main portion of the glass panel W in the thickness direction are contacted with the circumferential portion of the grinding groove 74 of the outer peripheral grinding wheel 72 and are subjected to helical grinding. When the processing point reaches the corner R portion of the glass panel W, the chuck table 73 rotates to process the corner R. At this time, it becomes the same as grinding of the circular portion, and the contact area becomes small. Therefore, the contact of the upper surface slope of the grinding groove 74 becomes weak, and the central portion in the thickness direction is mainly ground. Hereinafter, the glass panel W is similarly processed until it makes one round.

  FIG. 7 is a side view showing a state in which the lower surface of the glass panel is being processed. At the point where the above processing is performed once, the outer peripheral grinding wheel 72 is raised in the Z-axis direction from the state of FIG. Is lowered in the Z-axis direction so that the lower surface slope of the grinding groove 74 is in contact with the lower surface of the glass panel W and the lower surface slope 72d at the lower left end of FIG. That is, the grinding wheel is raised relative to the workpiece in the thickness direction. Thereafter, the glass panel W held on the chuck table 73 moves at a constant speed in the X-axis direction to perform chamfering on the second round.

  Since the grinding groove 74 is wider than the apparent thickness of the glass panel W, the upper surface of the glass panel W does not contact. The central portion and the main portion of the glass panel W in the thickness direction are contacted with the circumferential portion of the grinding groove 74 of the outer peripheral grinding wheel 72 and are subjected to helical grinding.

  As described above, the grinding groove 74 of the outer peripheral fine grinding wheel 72 is brought into contact with the glass panel W at an angle θ, the movement direction of the abrasive grains intersects with the movement direction of the glass panel W, and The width of the grinding groove 74 of the outer peripheral grinding wheel 72 is made wider than the apparent thickness of the workpiece when the outer circumferential grinding wheel 72 is tilted at an angle θ with respect to the workpiece. By moving up and down in the axial direction, helical grinding can be applied to chamfering of a linear portion such as OF or a material such as a rectangle or a polygon. Thereby, the surface roughness of the end face and the processing distortion are reduced, and even a high count grindstone can be used for a long time.

  Here, the inventor increases the angle θ in FIG. 6 so that the upper right end portion of the upper surface of the glass panel W comes into contact with the upper surface inclined surface 72u, and the lower surface inclined surface is in contact with the lower left end portion of the lower surface of the glass panel W. An evaluation was performed in which grinding was performed so that 72d abuts. Then, when grinding R of the corner | angular part of the glass panel W, it discovered that the situation where the glass panel W can always contact | abut only one of the upper surface inclined surface 72u and the lower surface inclined surface 72d generate | occur | produced. For this reason, in the corner | angular part of the glass panel W, it turned out that the part which grinding | polishing is not enough in any one of an upper surface or a lower surface occurs.

  Therefore, when the present inventor performs the helical polishing, the relationship between θ, y and the thickness t of the glass panel W in FIG. 6 is “only one of the upper surface or the lower surface of the glass panel W is the grinding groove 74. It has been found that θ, y, and t must be selected so as to contact one end (upper surface inclined surface 72u or lower surface inclined surface 72d) and the other does not contact the end portion (condition 1). Therefore, if any of these parameters is determined, the above condition 1 must be satisfied by adjusting the changeable parameters. At this time, it was found that it is preferable that y0 in FIG. This is because most of the grinding groove 74 can be used, so that the life of the grindstone is extended.

  FIG. 8 is a plan view for explaining the difference in contact between the peripheral grinding wheel 72 and the grinding groove 74 at the upper and lower ends in the thickness direction of the glass panel W between the processing of the circular portion and the processing of the straight portion. The contact area between the cylindrical portion of the grinding groove 74 of the fine grinding wheel 72 and the linear workpiece W1 is not only larger than the contact area between the cylindrical portion and the circular workpiece W2, but also the upper surface slope 72u or the lower surface slope 72d at the upper and lower ends of the grinding groove 74. The contact area L of the straight workpiece W1 is larger than the contact area M of the circular workpiece W2.

  Therefore, not only the grinding resistance of the linear workpiece W1 is larger than the grinding resistance of the circular workpiece W2, but also the chamfering of the linear workpiece W1 can be performed by chamfering the width in the thickness direction of the grinding groove 74 to the circular workpiece W2. become unable. Even if the grinding groove 74 is formed so that the chamfering can be performed symmetrically with respect to the circular workpiece W2, if the chamfering is performed on the straight workpiece W1, the shapes of the upper and lower surfaces are different.

  FIG. 9 shows an example of helical grinding by an axis inclination method in which one axis is added to the surface grinder 80 in contrast to the conventional end face processing of a plate material. As shown in FIG. 9, the precision stage 81 is arranged at an inclination angle α so that the workpiece 83 passes through the lowest point of the grindstone 82. The grindstone 82 is wider than the workpiece 83, and both surfaces are fixed to the vicinity of the machining surface by the vise 84.

  In this method, as shown in FIG. 10 (a), the grindstone 82 is fixed because the workpiece 83 is firmly fixed by the vise 84, the rotation axis of the grindstone 82 is horizontal with the machining surface, and the like. When pressed as indicated by the arrow V, the wobbling of the grindstone 82 impacts the workpiece 83 and damages the processed surface. Further, since the ground metal falls to the processed surface, scratches and scratches due to the scratch are generated on the processed surface.

  On the other hand, as shown in FIGS. 6 and 7, in the present invention, the grinding groove 74 of the outer peripheral grinding wheel 72 is inclined at an angle θ with respect to the workpiece W. The chuck table 73 mounts a flat surface of the glass panel W, and the surface is decompressed by an air compressor, a blower or the like, and the glass panel W is sucked and fixed. In the case of FIG. 10B in which the glass panel W is overhanged from the chuck table 73 and sucked and held in the vertical direction, the grinding groove 74 of the outer peripheral grinding wheel 72 comes into contact with the processing surface perpendicularly, The pressing force by the grinding wheel 72 works as shown by an arrow H.

  Therefore, a workpiece, for example, the glass panel W itself is slightly elastically deformed during processing, and coupled with the fact that the outer peripheral precision grinding stone 72 is a soft resin bond grinding stone, the impact such as runout is reduced. Therefore, there is no damage such as scratches on the machined surface, and the ground metal is discharged as shown by the arrow, and it does not fall on the machined surface, causing scratches and scratches on the machined surface. There is no.

  FIG. 11 is a side view showing an end face of a workpiece processed by the above-described method for manufacturing a chamfered substrate, and shows the state of the streak after grinding with a peripheral grinding wheel 72 which is a resin grindstone. . The grinding groove 74 has a sufficiently large width with respect to the thickness of the workpiece (substrate, workpiece) and is brought into contact with the workpiece at an oblique angle of 6 to 10 °. Chamfering was performed so that only one side was in contact with the work and not the other side. Actually, grinding with the upper surface abutting was performed once for the entire circumference of the end surface of the workpiece, then the lower surface was abutted, and further one round was performed for a total of two rounds of polishing and chamfering. .

  In conventional chamfering by helical grinding, a workpiece having a corner and a straight part was hit by only one of the upper and lower surfaces of the grinding groove of the grindstone, and good chamfering was not possible. In this way, the central portion C in the thickness direction becomes a characteristic streak of helical grinding according to the angle at which the grindstone is inclined, and the shape is not deformed with good surface roughness.

  In addition, both the upper and lower ends are symmetrical in angle and size, and the widths of Tu and Td are uniform in the drawing, and the corners of the end face of the work material at the end of the grinding groove are helically ground, the angle, The direction differs as much as the end of the grinding groove hits, which clearly appears.

  Furthermore, along with the thinning and weight reduction of smartphones and tablets, conventionally, the glass substrate was cut into a predetermined size and then chemically strengthened, followed by masking printing to form sensor electrodes. . On the other hand, according to the method for manufacturing a chamfered substrate, after performing chemical strengthening treatment with a large glass substrate, masking printing, forming a sensor electrode, and then performing cutting and chamfering, That is, even when the end face is not chemically strengthened, a good machined surface roughness can be obtained, and the occurrence of microcracks can be suppressed. As a result, the production efficiency is greatly improved, and a practically sufficient end face strength can be obtained.

  Furthermore, not only the surface roughness and shape symmetry, but also after the grinding groove is corrected (tooling) once, it continues until the grinding ability declines, the predetermined outer peripheral surface width, outer peripheral angle, and outer peripheral shape are not satisfied. The number of sheets that can be processed can be increased. Further, when the chamfering process is repeated by repeating the tooling of the outer peripheral grinding wheel 72 which is a resin grindstone, the number of sheets that can be machined before the resin grindstone becomes smaller than a predetermined diameter due to wear and becomes unusable is increased. be able to.

  As described above, in FIGS. 6 and 7, the helical grinding using the outer peripheral fine grinding wheel 72 has been described. However, during the rough grinding, that is, when the outer peripheral coarse grinding wheel 69 is used, the helical grinding that makes two rounds may be performed similarly. . According to this, at the time of fine grinding, it is possible to prevent wear, clogging, and deformation of the groove shape of the grinding groove 74 of the outer peripheral fine grinding wheel 72 and perform better chamfering.

  Further, the upper part of the end surface of the workpiece is ground so as to make one round with the grinding groove 74 over the entire circumference (upper grinding), and then the grinding wheel 69 or 72 is relatively relative to the thickness direction of the workpiece. In this case, the lower part is ground once (lower part grinding), but this order may be reversed, and the upper surface slope which is the end part of the grinding groove 74 at the upper part and the lower part of the end face of the workpiece. You may grind separately the center part which neither 72u nor the lower surface inclined surface 72d touches.

  FIG. 12 shows center grinding (a), upper grinding (b), and lower grinding (c). In the central grinding (a), when the chuck table 73 is fed toward the outer peripheral precision spindle 71, the upper surface slope 72u at the upper right end portion and the lower surface slope 72d at the lower left end portion of the grinding groove 74 are both glass panels. Machining is started without coming into contact with the upper and lower surfaces of W, and thereafter, the glass panel W held on the chuck table 73 is moved at a constant speed in the Y-axis direction to perform chamfering. When the grinding groove 74 has an apparent thickness y0 of the glass panel W (see FIG. 6), that is, when the grinding groove 74 of the outer peripheral grinding wheel 72 is tilted at an angle θ, the diameter of the grinding groove 74 is D, and the glass panel that is the workpiece It is at least 20-30% wider than the thickness considering both the thickness t of W.

  The central portion and the main portion of the glass panel W in the thickness direction are contacted with the circumferential portion of the grinding groove 74 of the outer peripheral grinding wheel 72 and are subjected to helical grinding. When the processing point reaches the corner R, the chuck table 73 is rotated to process the corner R. Since the end in the thickness direction of the glass panel W is not ground by the upper and lower slopes (or upper and lower ends) of the grinding groove 74, it is suitable for processing regardless of the outer peripheral shape of the glass panel W without affecting the vertical asymmetry. It is convenient to cut out the shape when the circular part as shown in 2 is the main part and there is a straight part such as the OF part.

    FIG. 12B shows the upper grinding. From the state of FIG. 12A, the outer peripheral grinding wheel 72 is lowered in the Z-axis direction or the chuck table 73 is raised in the Z-axis direction, and the upper right end of the grinding groove 74 is shown. The upper surface of the glass panel W, the upper right end in the figure, is brought into contact with the upper surface slope 72u of the unit. That is, the grinding wheel is lowered relative to the workpiece in the thickness direction. Thereafter, the glass panel W held on the chuck table 73 is moved at a constant speed in the Y-axis direction to perform chamfering by helical grinding.

  FIG. 12C shows the grinding of the lower part. From the state of FIG. 12B, the outer peripheral grinding wheel 72 is raised in the Z-axis direction or the chuck table 73 is lowered in the Z-axis direction, and the lower surface slope of the grinding groove 74 Is in contact with the lower surface of the glass panel W, the lower surface slope 72d at the lower left end in the figure. That is, the grinding wheel is raised relative to the workpiece in the thickness direction. Thereafter, the glass panel W held on the chuck table 73 moves at a constant speed in the Y-axis direction, and chamfering on the third round is performed following FIGS. 12A and 12B.

  Although FIG. 12 demonstrated center part grinding (a), upper part grinding (b), and lower part grinding (c) in this order, it is not restricted to this, Upper part grinding (b), Central part grinding ( The order of a) and lower grinding (c) may be arbitrary. However, the point that grinding (a) at the center portion can be performed first, the shape can be cut out first, and then the upper portion grinding (b) and the lower portion grinding (c) can be performed more carefully and accurately. Is excellent.

  Further, as the work material, particularly when the circular portion as shown in FIG. 2 is mainly used and there is a straight portion such as the OF portion, the grinding of the central portion (a), the grinding of the upper portion (b), Each grinding (c) does not require one round of the outer periphery of the workpiece. For example, if the circular portion is subjected only to the upper grinding (b) and the lower grinding (c), the straight portion is subjected to the central grinding (a), the upper grinding (b), and the lower grinding (c). The surface roughness is good, the processing time is shortened without causing the shape collapse, and the grinding groove 74 can be prevented from being worn, clogged and deformed.

  6, 7, and 12 describe the rising or lowering in the thickness direction of the workpiece, but FIG. 13 illustrates the relationship between the upper surface inclined surface 72 u and the lower surface inclined surface 72 d of the grinding groove 74 of the outer peripheral grinding wheel 72. The relationship between the slope of the grinding groove 74 and the chamfer angle will be described. FIG. 13A shows a state in which the peripheral grinding wheel 72 is not tilted but is in contact with the workpiece W, and the chamfering angles coincide with the angles of the upper and lower slopes 72u and 72d of the grinding groove 74. FIG. .

  In order to perform helical grinding, the state in which the outer peripheral grinding wheel 72 is tilted is shown in FIG. 13B, which is 3 to 15 °, preferably 6 to 10 °. The contact area between 72u and the upper surface of the workpiece W is not significantly different from FIG. Accordingly, as already shown in FIG. 11, the upper and lower ends (Tu and Td regions) of the workpiece W are also inclined in a different direction as compared with the central portion C, so that the effect of helical grinding is achieved. Is sufficiently obtained, and the processing distortion and surface roughness are improved in the same manner as the central portion. The appearance of these three streaks is also a feature of the above embodiment.

  In order to make the explanation easy to understand, by not tilting the peripheral grinding wheel 72 of FIG. 13A, the peripheral grinding wheel 72 is tilted with reference to the fact that the slope of the grinding groove 74 coincides with the chamfering angle. This is shown in FIG. On the contrary, the inclined surface may be matched with the chamfering angle of the workpiece W in FIG. Thereby, even when the amount of grinding is small at the start of processing, the contact area between the upper surface slope 72u and the upper surface of the workpiece W is increased, and the surface roughness of the upper and lower ends of the workpiece W is improved.

DESCRIPTION OF SYMBOLS 10 ... Processing part, 20 ... Supply / recovery part, 30 ... Wafer cassette, 31 ... Cassette table, 40 ... Supply / recovery robot, 50 ... Transfer arm, 60 ... Wafer feeder, 61 ... Fine outer peripheral grinding device, 62 ... Coarse peripheral grinding 65, chuck table drive motor, 66 ... chuck table, 67 ... outer periphery roughing motor, 68 ... outer periphery roughing spindle (rotating shaft), 69 ... outer periphery rough grinding wheel, 70 ... outer periphery fine grinding motor, 71 ... outer periphery precision Sharpening spindle (rotating shaft), 72 ... fine grinding wheel for outer periphery, 72d ... lower slope, 72u ... upper slope, 73 ... chuck table, 74 ... grinding groove, 80 ... surface grinding machine, 81 ... precision stage, 82 ... grinding wheel, 83 ... Work material, 84 ... Vise, W ... Wafer, glass panel, work material, y0 ... Apparent thickness of work material

Claims (13)

A method for manufacturing a chamfered substrate in which an end face of a plate-like workpiece is ground with a grinding groove of a grinding wheel,
Adsorb the plane of the workpiece in the thickness direction with a chuck table smaller than the outer peripheral shape of the workpiece,
Inclining the rotation axis of the grinding wheel with respect to the axis in the thickness direction that is perpendicular to the plane of the workpiece, and pressing the grinding groove against the end surface of the workpiece from the vertical direction to contact the grinding wheel,
Grinding the upper or lower part of the end face of the workpiece with the grinding groove,
Then, the grinding wheel is raised or lowered in the thickness direction relative to the workpiece and then ground again. A method for manufacturing a chamfered substrate according to claim 1,
A method for manufacturing a chamfered substrate, characterized in that the width of the grinding groove is larger than the apparent thickness of the workpiece when the rotation axis of the grinding wheel is tilted. A method for manufacturing a chamfered substrate according to claim 1 or 2,
Grinding the upper part of the end face of the workpiece with the grinding groove, then raising the grinding wheel relative to the workpiece in the thickness direction and grinding again;
Alternatively, the lower part of the end face of the workpiece is ground with the grinding groove, and then the grinding wheel is lowered relative to the workpiece in the thickness direction and is ground again. Chamfer substrate manufacturing method. A method for producing a chamfered substrate according to any one of claims 1 to 3,
The upper or lower part of the end face of the workpiece is ground so as to make one round with the grinding groove over the entire circumference, and then the grinding wheel is raised relative to the workpiece in the thickness direction. Alternatively, the chamfered substrate is manufactured by lowering and grinding one round. A method for manufacturing a chamfered substrate according to any one of claims 1 to 4,
A method for manufacturing a chamfered substrate, wherein a rotating shaft of the grinding wheel is inclined by 3 to 15 degrees. A method for producing a chamfered substrate according to claim 2,
The method of manufacturing a chamfered substrate, wherein the processing of the end surface of the workpiece is performed by grinding the upper portion of the end surface of the workpiece, grinding the central portion, and grinding the lower portion. A method for manufacturing a chamfered substrate according to claim 6,
The method of manufacturing a chamfered substrate, wherein the upper grinding, the central grinding, and the lower grinding are performed so that the end face of the workpiece is made to make one round with the grinding groove over the entire circumference. In a chamfering device that chamfers the end face of a plate-shaped workpiece with a grinding groove of a grinding wheel,
A chuck table that adsorbs the plane of the workpiece in the thickness direction and is smaller than the outer peripheral shape of the workpiece;
The grinding wheel that inclines the rotation axis with respect to the axis in the thickness direction that is perpendicular to the plane of the workpiece, and presses the grinding groove against the end surface of the workpiece from the vertical direction to contact the grinding wheel,
And grinding the upper or lower portion of the end face of the workpiece with the grinding groove, and then grinding the grinding wheel again by raising or lowering the grinding wheel relative to the workpiece in the thickness direction. A chamfering device characterized by that. The chamfering device according to claim 8,
The chamfering device according to claim 1, wherein a width of the grinding groove is larger than an apparent thickness of the workpiece when the rotation axis of the grinding wheel is tilted. The chamfering device according to claim 8 or 9,
The upper part of the end face of the workpiece is ground with the grinding groove, and then the grinding wheel is raised in the thickness direction relative to the workpiece and ground again, or the workpiece A chamfering apparatus, wherein a lower part of an end face is ground with the grinding groove, and then the grinding wheel is lowered relative to the workpiece in the thickness direction and ground again. The chamfering device according to any one of claims 8 to 10,
The upper or lower part of the end face of the workpiece is ground so as to make one round with the grinding groove over the entire circumference, and then the grinding wheel is raised relative to the workpiece in the thickness direction. Alternatively, the chamfering apparatus is characterized in that the chamfering apparatus is lowered and further ground once. The chamfering device according to any one of claims 8 to 11,
A chamfering apparatus characterized in that a rotating shaft of the grinding wheel is inclined by 3 to 15 degrees. The chamfering device according to claim 8,
The chamfering apparatus is characterized in that the end surface of the workpiece is ground by grinding an upper portion of the end surface, a central portion, and a lower portion.