JP2021094693A - Manufacturing method of chamfered baseboard and chamfering device used in the same - Google Patents

Abstract

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 method and an apparatus for manufacturing a highly accurate chamfered substrate on the end face of various materials such as silicon, sapphire, compound, and glass, particularly a plate-shaped workpiece such as a semiconductor wafer and a glass panel. It is suitable for end face processing of a work material having a straight portion other than a circular portion.

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

Silicone is hard and brittle, and if the end face of the wafer remains sharp during slicing, it will easily crack or chip during handling such as transportation and alignment in the subsequent processing process, and fragments will damage or contaminate the wafer surface. Or something. To prevent this, the end face of the cut wafer is chamfered with a chamfering grindstone coated with diamond. At this time, it is also included to match the diameters of the outer circumferences with variations, to match the width of the orientation flat (OF), and to match the dimensions of a minute notch called a notch.

In addition, the glass substrate used for smartphones and tablets, which has been pursued to be thinner and lighter, is subjected to masking printing, sensor electrode formation, and then cutting. The generation of microcracks 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, but in this case, grinding marks in the circumferential direction are likely to occur in the chamfered portion. Therefore, it is known to perform so-called helical grinding in which, for example, a resin bond grindstone (resin grindstone) is tilted with respect to the wafer to grind the chamfered portion of the wafer.

When helical grinding is performed, not only the processing strain of the chamfered portion is reduced as compared with normal grinding, but also 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 machined, the vertical angle of the groove of the resin grindstone gradually changes, and as a result, the vertical asymmetry of the chamfered portion of the wafer is further increased. growing. Therefore, the edge of the disc-shaped tool is ground by the groove of the first grindstone in which a groove having an asymmetrical shape is formed around the groove, and the edge of the tool is formed into a groove shape that is asymmetrical in the vertical direction. A groove is formed around the second grindstone by tilting the grindstone relatively, and the wafer is tilted relative to the groove direction by the second grindstone to obtain a resin grindstone that is substantially symmetrical in the vertical direction and chamfered. It is known to finely grind a portion, and is described in, for example, Patent Document 1.

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

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

JP-A-2007-165712 Japanese Unexamined Patent Publication No. 2007-21586 Japanese Unexamined Patent Publication No. 2005-153129

In the above-mentioned prior art, the one described in Patent Document 1 requires a first grindstone in which a groove having a vertically asymmetrical shape is formed around it, and it is difficult to determine the shape thereof. In the case of a circular waiha, the same shape can be used for the entire circumference, so it can be uniquely determined. However, a waiha substrate with an OF, a rectangular or polygonal waiha with an arc at the corner, a substrate, a cover glass, etc. are circular. If there is a part and a non-circular part, not only is it more difficult, but also the change in the vertical angle of the groove of the resin grindstone becomes large at the position where the circular part shifts to the non-circular part, and the corner part, and the entire circumference is helically ground. It was extremely difficult to do. That is, at the corners of the substrate (work) having corners, only one of the upper surface and the lower surface of the groove of the grindstone was hit, and good chamfering could not be performed.

In the case described in Patent Document 2, the grinding process is complicated, and it is good when the grinding process is mainly circular and the number of non-circular portions is small, but it is difficult to apply in the case of a rectangle or a polygon.

In the case described in Patent Document 3, the grindstone must be moved relatively in the thickness direction of the wafer during chamfering. Therefore, in order to improve the accuracy of chamfering, the thickness direction of the wafer or the grindstone must be controlled. It was complicated and difficult.

An object of the present invention is to solve the above-mentioned problems of the prior art, and even a wafer substrate with OF (orifura), 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 purpose is to facilitate grinding, increase the contact area between the workpiece and the grindstone, improve the surface roughness, and improve the shape loss.

In order to achieve the above object, the present invention is a method for manufacturing a chamfered substrate in which the end face of a plate-shaped work material is ground by a grinding groove of a grinding wheel, and the plane of the work material is oriented in the thickness direction. It is attracted by a chuck table smaller than the outer peripheral shape of the work material, the rotation axis of the grinding wheel is tilted with respect to the axis in the thickness direction perpendicular to the plane of the work material, and the grinding groove is formed into the work work. It is pressed against the end face of the material from the vertical direction to abut, and the upper or lower part of the end face of the work material is ground by the grinding groove, and then the grinding wheel is placed in the thickness direction relative to the work material. Grind again by raising or lowering.

Further, in the above, it is preferable that the width of the grinding groove is made larger than the apparent thickness of the work material when the rotation axis of the grinding wheel is tilted.

Further, in the above, the upper part of the end face of the work material is ground by the grinding groove, and then the grinding wheel is raised relative to the work material in the thickness direction to grind or grind again. It is preferable to grind the lower part of the end face of the work material in the grinding groove, and then lower the grinding wheel in the thickness direction relative to the work material to grind again.

Further, in the above, the upper part or the lower part of the end face of the work material is ground so as to make one round in the grinding groove over the entire circumference, and then the grinding wheel is placed relative to the work material. It is preferable to raise or lower in the thickness direction and further grind one round.

Further, in the above, it is preferable to incline the rotation axis of the grinding wheel by 3 to 15 °.

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

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

Further, according to the present invention, in a chamfering device for chamfering the end face of a plate-shaped work material with a grinding groove of a grinding wheel, the flat surface of the work material is adsorbed in the thickness direction, and the outer peripheral shape of the work material is used. The grinding is such that the rotation axis is tilted with respect to the small chuck table and the axis in the thickness direction perpendicular to the plane of the work material, and the grinding groove is pressed against the end face of the work material from the vertical direction to come into contact with the grinding. A grindstone is provided, and an upper part or a lower part of an end surface of the work material is ground by the grinding groove, and then the grinding grindstone is raised or lowered in the thickness direction relative to the work material. It is to be ground again.

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

Further, in the above, the upper part of the end face of the work material is ground by the grinding groove, and then the grinding wheel is raised relative to the work material in the thickness direction to grind again. Alternatively, it is preferable to grind the lower part of the end face of the work material in the grinding groove, and then lower the grinding wheel in the thickness direction relative to the work material to grind again.

Further, in the above, the upper part or the lower part of the end face of the work material is ground so as to make one round in the grinding groove over the entire circumference, and then the grinding wheel is relative to the work material. It is preferable to raise or lower the thickness in the thickness direction and further grind one round.

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

Further, in the above, it is preferable that the end face of the work piece is ground by grinding the upper part of the end face, grinding the central part, and grinding the lower part, respectively.

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 loss can be reduced.

The plan view which shows the main part of the chamfering apparatus which concerns on one Embodiment of this invention. The perspective view which shows the structure of the processed part in one Embodiment. (The work material is circular and straight) The plan view in FIG. The perspective view which shows the structure of the processed part in one Embodiment. (Mainly the straight part of the work material) The plan view in FIG. The side view which shows the relationship between the grinding groove and the work material in one Embodiment. (Processing of the upper surface) The side view which shows the relationship between the grinding groove and the work material in one Embodiment. (Processing of the lower surface) The plan view explaining the contact between the work material and the upper and lower ends of a grinding wheel. The perspective view which shows the helical grinding of the end face processing of the conventional plate material. The side view explaining the difference between the conventional grinding and the grinding by one Embodiment. A side view showing an end face of a work material processed by the method for manufacturing a chamfered substrate according to an embodiment. The side view which shows the procedure of the manufacturing method of the chamfered substrate by another embodiment. The side view which shows the detail of the grinding wheel and the work material which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The invention is not limited by this embodiment, and the components in the embodiment 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 device according to an embodiment of the present invention. The chamfering device mainly has a supply / recovery unit 20 and a processing unit 10, and is further composed of a pre-alignment unit, a cleaning unit, a post-measurement unit, a transport unit, and the like, although not shown.

The wafer processing process is performed in the order of slicing → chamfering → wrapping → etching → donor killer → fine chamfering, and various cleanings are used to remove stains between the processes. Silicone is hard and brittle, and if the end face of the wafer remains sharp during slicing, it will easily crack or chip during handling such as transportation and alignment in the subsequent processing process, and fragments will damage or contaminate the wafer surface. Or something. In order to prevent this, in the chamfering process, the end face of the cut wafer is chamfered with a chamfering grindstone coated with diamond.

The chamfering step may be performed after the wrapping step. At this time, the diameters of the outer circumferences that vary are matched, the width of the orientation flat (OF) is matched, and the dimensions of a minute notch called a notch are matched.

The supply / recovery unit 20 supplies the chamfered wafer W from the wafer cassette 30 to the processing unit 10 and collects the chamfered wafer into the wafer cassette 30. This operation is performed by the supply / recovery robot 40. The wafer cassette 30 is set on the cassette table 31 and contains a large number of wafers W to be chamfered. The supply / recovery robot 40 takes out 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 is provided with a 3-axis rotary type transfer arm 50, and the transfer arm 50 is provided with a suction pad (not shown) on the upper surface thereof. The transfer arm 50 holds the wafer W by vacuum suctioning the back surface of the wafer W with a suction pad. That is, the transport arm 50 of the supply / recovery robot 40 can move back and forth, move up and down, and turn while holding the wafer W, and transports the wafer W by combining these operations.

The processing portion 10 is arranged on the front portion of the wafer chamfering device, and performs all processing of the outer peripheral chamfering of the wafer W, that is, from roughing to finishing. The processing section 10 includes a wafer feed device 60, an outer peripheral rough grinding device 62, a transfer arm 63 for transporting the wafer W, and an outer peripheral fine grinding device 61.

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

The outer peripheral rough grinding device 62 is arranged at a position separated by a predetermined distance in the Y-axis direction with respect to the chuck table 66 of the wafer feeding device 60. The 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 and rotates. The outer peripheral rough grinding spindle 68 is configured to be movable in each of the front-rear direction (Y-axis direction) and the up-down direction (Z-axis direction) by being driven by a driving means (not shown).

An outer peripheral rough grinding wheel 69 that roughens (roughly grinds) the outer periphery of the wafer W is mounted on the outer 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 (total shape grindstone), and by pressing the outer periphery of the wafer W against these grooves, the outer periphery of the wafer W is roughened (the outer circumference of the wafer W is roughened. Rough grinding).

The outer peripheral fine grinding device 61 is arranged at a position separated by a predetermined distance in the X-axis direction from the chuck table 66 of the wafer feed device 60. The outer peripheral fine grinding device 61 has an outer peripheral fine grinding spindle 71 that is driven by an outer peripheral fine grinding motor 70 and rotates. The outer peripheral refined spindle 71 is configured to be movable in each of the left-right direction (X-axis direction) and the up-down direction (Z-axis direction) by being driven by a driving means (not shown). An outer peripheral fine grinding wheel 72 that finishes (finely grinds) the outer periphery of the wafer W is mounted on the outer peripheral fine grinding spindle 71, and serves as a rotation axis thereof.

The outer peripheral grinding wheel 72 has a groove for outer peripheral grinding formed on the outer peripheral surface thereof (total shape grindstone), and the outer periphery of the wafer W is finished by pressing the outer periphery of the wafer W against the groove.

At this time, the wafer is subjected to helical grinding in a state where the rotation axis of the outer peripheral refined spindle 71 is tilted 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. Finish the chamfering of the outer circumference of W.

As a result, the movement direction of the abrasive grains intersects with the movement direction of the outer circumference of the wafer W, and the contact area is increased, so that the wear of the grindstone can be suppressed and the shape of the outer circumference can be reduced. The roughness of the machined surface (ground surface) is improved.

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

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

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

When the alignment operation is completed, the outer peripheral rough grinding motor 67 is driven. Next, grinding (roughing) with the outer peripheral 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 wheel 69, for example, a metal bond grindstone having diamond abrasive grains having a diameter of 202 mm and having a particle size of # 800 can be used. Further, the outer peripheral rough grinding spindle 68 is a spindle driven by a built-in motor using ball bearings, and is rotated at a predetermined rotation speed, for example, a rotation speed of 8,000 rpm.

When the outer peripheral rough grinding spindle 68 is sent toward the chuck table 66, the outer periphery of the wafer W comes into contact with the grinding groove for outer peripheral rough grinding formed on the outer peripheral rough grinding wheel 69, and the outer peripheral portion of the wafer W is rough ground. Grinding is performed by the grindstone 69, and roughing of the outer peripheral chamfer of the wafer W is started.

After the rough machining by the outer peripheral rough grinding wheel 69 is started, since the wafer W in FIG. 2 is circular at first, the wafer W held by the chuck table 66 starts rotating in the arrow direction at a constant speed. When this rotation angle, that is, the OF portion where the machining point is a straight portion is reached, the feed amount in the direction toward the chuck table 66, which is the Y direction of the outer peripheral rough grinding spindle 68, is increased, and the outer peripheral rough grinding spindle 68 is X. Process the straight part by moving it linearly in the direction. After that, when the machining of the straight portion is completed, the plate-shaped wafer W held by the chuck table 66 is rotated again in the direction of the arrow at a constant speed, the remaining circular portion is ground, and the rough machining by the outer peripheral rough grinding wheel 69 is performed. To finish.

Next, the finishing process by the outer peripheral fine grinding wheel 72 is performed in the same manner. As the outer peripheral fine grinding wheel 72, a resin bond grindstone having diamond abrasive grains is suitable. Further, the outer peripheral chamfer of the waha W is performed in a state where the rotation axis of the outer circumference refined spindle 71 is tilted by 3 to 15 °, preferably 6 to 10 ° in the tangential direction of the outer circumference of the waha W with respect to the rotation axis of the chuck table 66. Finishing is done.

Further, the chamfering groove of the outer peripheral fine grinding wheel 72 is formed by a truer, but detailed description thereof will be omitted. Further, as the outer peripheral rough grinding wheel 69, for example, one in which metal powder such as Fe, Cr, Cu or the like is used as a main component and diamond abrasive grains are mixed and formed is used. As the material of the turret, a material capable of grinding the outer peripheral fine grinding wheel 72 while being able to be processed by the outer peripheral rough grinding wheel 69 is adopted.

For example, it is desirable that abrasive grains made of silicon carbide are bonded with a phenol resin by adding a filler or the like as necessary, and this is formed into a disk-shaped turret. As the material of the outer peripheral fine grinding wheel 72, a grinding groove 74 can be formed around the grinding wheel by grinding with a truer, while a chamfered portion such as a silicon wafer can be finely ground by the formed polishing. For example, it is desirable that a phenol resin, an epoxy resin, a polyimide resin, a polystyrene resin, a polyethylene resin or the like is used as a main component, and a diamond abrasive grain or a cubic boron nitride abrasive grain is mixed and molded.

Further, as the outer peripheral fine grinding wheel 72, for example, a resin bond grindstone having diamond abrasive grains having a diameter of 50 mm and having a particle size of # 3000 is used. The outer peripheral Seiken spindle 71 is a built-in motor-driven spindle that uses air bearings and is rotated at a rotation speed of 35,000 rpm.

FIG. 4 is a perspective view showing the configuration of the processed portion when the material to be processed is not circular but rectangular, and FIG. 5 is similarly a plan view. When the work material is not circular but rectangular, as shown in FIGS. 4 and 5, the processing of the straight portion is mainly performed.

As smartphones and tablets become thinner and lighter, glass substrates, cover glass, sapphire, and ceramics are used for the surface, and end face strength becomes important. In mirror grinding, chipping due to abrasive grains is suppressed and good surface roughness is achieved. Is required. Chamfering processing quality, processed surface roughness, occurrence of microcracks, etc. directly affect the end face strength of the glass substrate.

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

When the outer peripheral fine grinding 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 peripheral fine grinding groove, which is a chamfering processing groove formed on the outer peripheral grinding grindstone 72. , The outer peripheral portion of the glass panel W is helically ground by the outer peripheral fine grinding grind 72, and the outer peripheral chamfering process of the glass panel W is started. Since the glass panel W in FIGS. 4 and 5 is rectangular after the machining by the outer peripheral grinding wheel 72 is started, the glass panel W held by the chuck table 73 starts moving at a constant speed in the Y-axis direction. When the machining point reaches the corner portion, the chuck table 73 moves in the Y-axis direction while rotating 90 ° to machine the next straight portion. Hereinafter, the entire outer circumference of the glass panel W will be processed in the same manner.

Further, the grinding wheel is used by impregnating a chamfering wheel material having a porous surface with a lubricant together with a saturated fatty acid solution and drying the surface to obtain a lubricant-impregnated grindstone. It is desirable to do. As a result, the lubricant is reliably supplied to the cutting point of the grindstone, and the cutting point temperature can be lowered to a predetermined temperature or lower. Moreover, since the coolant is water, environmental pollution by the coolant can be prevented. Further, in the waiha chamfering device, since the abrasive stone is impregnated with the lubricant, the lubricant can be supplied to the cutting point for a long period of time, and since the coolant is water, low temperature and environment-friendly processing becomes possible.

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

Specifically, for the size of the chuck table 73, 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, Q = (1). It is preferable to set .3 to 1.7) P, more preferably Q = 1.5P, from the viewpoint of fixing and grinding by adsorption of the glass panel W. That is, while avoiding the influence of deformation, bending, and distortion of the glass panel W on the processing accuracy, the material to be processed and the glass panel W itself are slightly elastically deformed during processing, and the outer peripheral fine grinding wheel 72 is a soft resin bond grindstone. Coupled with that, the impact such as the runout is mitigated. The same applies to the Y-axis direction, and it is desirable that N = (1.3 to 1.7) H in FIG. 5, and more preferably N = 1.5H. That is, the shape of the chuck table 73 is smaller than the outer peripheral shape of the work material, and it is desirable that the shape of the chuck table 73 is 0.6 to 0.8 times larger than the planar shape of the glass panel W in both vertical and horizontal directions. The shape of the rectangular glass panel W is preferably about 120 mm × 60 mm in length × 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 refined spindle 71 is tilted 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 finely ground on the outer circumference. It abuts on the grinding groove 74 of the grindstone 72 at this angle θ, and the moving direction of the abrasive grains intersects with the moving direction of the glass panel W. Further, if the inclination angle is too large, it is not preferable in terms of an increase in grinding resistance, chipping of vertical 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 outer peripheral grinding wheel 72 and the workpiece W. As shown in the figure, the width y of the grinding groove 74 of the outer peripheral grinding wheel 72 is the outer peripheral grinding wheel 72. When the grinding groove 74 of the grinding wheel 72 is tilted by 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 comes into contact with the upper surface of the workpiece W. The distance to the non-contact position, that is, the apparent thickness of the work piece when the grinding groove 74 is tilted by an angle θ, y> y0 wider than the dimension y0 from the right end to the left end in FIG. y0 is approximately Dtanθ + t / cosθ, where D is the diameter of the grinding groove 74 and t is the thickness of the workpiece W. As a method of widening the width of the grinding groove 74, the groove for transfer at the time of tooling may be widened in advance, or the tooling at the time of tooling is moved up and down in the Z-axis direction to widen the grinding groove 74. You may.

Next, the machining 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 processed, and when the outer peripheral refined spindle 71 is sent toward the chuck table 73, the upper surface slope 72u of the upper right end portion of the grinding groove 74 is formed. The upper surface of the glass panel W and the upper right end portion in FIG. 6 come into contact with each other to start machining, 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.

The lower surface of the glass panel W does not come into contact with the lower surface of the glass panel W because the grinding groove 74 is wider than the apparent thickness of the glass panel W. The central portion and the main portion of the glass panel W in the thickness direction are helically ground in contact with the circumferential portion of the grinding groove 74 of the outer peripheral grinding wheel 72. When the processing point reaches the corner radius portion of the glass panel W, the chuck table 73 rotates to process the corner radius portion. At this time, it is the same as grinding a circular portion, and the contact area becomes smaller, so that the contact on the upper slope of the grinding groove 74 becomes weaker, and the central portion in the thickness direction is mainly ground. Hereinafter, in the same manner, processing is performed until the outer circumference of the glass panel W makes one round.

FIG. 7 is a side view showing a state in which the lower surface of the glass panel is processed. At the point where the above processing makes one round, the outer peripheral grinding wheel 72 is raised in the Z-axis direction from the state of FIG. 6, or the chuck table 73 is formed. Is lowered in the Z-axis direction so that the lower surface slope of the grinding groove 74 comes into 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 in the thickness direction relative to the work piece. After that, the glass panel W held on the chuck table 73 moves at a constant speed in the X-axis direction to chamfer the second lap.

The upper surface of the glass panel W does not come into contact with the upper surface of the glass panel W because the grinding groove 74 is wider than the apparent thickness of the glass panel W. The central portion and the main portion of the glass panel W in the thickness direction are helically ground in contact with the circumferential portion of the grinding groove 74 of the outer peripheral grinding wheel 72.

As described above, the grinding groove 74 of the outer peripheral fine grinding grindstone 72 is tilted at an angle θ to come into contact with the glass panel W so that the moving direction of the abrasive grains intersects with the moving direction of the glass panel W. Make the width of the grinding groove 74 of the outer peripheral fine grinding grindstone 72 wider than the apparent thickness of the work piece when the outer peripheral fine grinding grindstone 72 is tilted by an angle θ with respect to the work material. By moving up and down in the axial direction, it becomes possible to apply helical grinding to chamfering a straight portion such as OF or a material such as a rectangle or a polygon. As a result, the surface roughness and processing distortion of the end face are reduced, and even a high-count grindstone can be used for a long time.

Here, the present inventor increases the angle of θ in FIG. 6, so that the upper right end of the upper surface of the glass panel W abuts on the upper surface slope 72u, and the lower surface slope is on the lower left lower end of the lower surface of the glass panel W. An evaluation was carried out in which grinding was performed so that 72d was in contact with each other. Then, when grinding the R at the corner of the glass panel W, it was found that the glass panel W always comes into contact with only one of the upper surface slope 72u and the lower surface slope 72d. For this reason, it has been found that at the corners of the glass panel W, there is always a portion on either the upper surface or the lower surface where grinding is insufficient.

Therefore, the present inventor has a relationship of θ, y, and the thickness t of the glass panel W in FIG. 6 when performing helical polishing, “only one of the upper surface and the lower surface of the glass panel W is the grinding groove 74. It has been found that θ, y, t must be selected so that the end (upper slope 72u or lower slope 72d) is in contact and the other is not in contact with the end ”(Condition 1). Therefore, if any of these parameters is determined, the above condition 1 must be satisfied by adjusting the changeable parameter. At that time, it was found that it is preferable that y0 in FIG. 6 has a value as close to y as possible within the range satisfying condition 1. As a result, 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 outer peripheral fine grinding grindstone 72 and the grinding groove 74 at the upper and lower ends of the glass panel W in the thickness direction 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 precision grinding wheel 72 and the straight work W1 is not only larger than the contact area between the cylindrical portion and the circular work W2, but also the upper and lower end slopes 72u or the lower surface slope 72d of the upper and lower ends of the grinding groove 74. The contact area L of the linear work W1 with is larger than the contact area M of the circular work W2.

Therefore, not only the grinding resistance of the straight work W1 is larger than the grinding resistance of the circular work W2, but also when the width of the grinding groove 74 in the thickness direction is chamfered according to the circular work W2, the straight work W1 can be chamfered. become unable. Further, even if the grinding groove 74 is created so that the circular work W2 can be chamfered vertically symmetrically, the shapes of the upper and lower surfaces will be different if the grinding groove 74 is chamfered with respect to the straight work W1.

FIG. 9 shows an example of helical grinding by an axial tilting method in which one axis is added to the surface grinding machine 80 as opposed to the conventional end face machining of a plate material. As shown in FIG. 9, the precision stage 81 is arranged at an inclination angle α so that the work piece 83 passes through the lowest point of the grindstone 82. The grindstone 82 is wider than the work piece 83, and both sides are fixed close to the machined surface by the vise 84.

In this method, as shown in FIG. 10A, the grindstone 82 is formed from the point that the work piece 83 is firmly fixed by the vise 84 and the rotation axis of the grindstone 82 is horizontal to the machining surface. It is pressed as shown by the arrow V, and the runout of the grindstone 82 causes an impact on the work piece 83, causing damage to the machined surface. In addition, since the ground chirico falls on the machined surface, scratches due to the chirico and streaks due to scratches are generated on the machined 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 tilted by an angle θ with respect to the work piece W. Further, a flat surface of the glass panel W is placed on the chuck table 73, and the surface of the chuck table 73 is depressurized by an air compressor, a blower, or the like to attract and fix the glass panel W. In the case of FIG. 10B in which the glass panel W is overhung from the chuck table 73 and is attracted and held in the vertical direction, the grinding groove 74 of the outer peripheral grinding wheel 72 abuts perpendicularly to the machined surface, and the outer peripheral grinding wheel 72 is vertically contacted. The pressing force of the grinding wheel 72 works as shown by the arrow H.

Therefore, the material to be processed, for example, the glass panel W itself is slightly elastically deformed during processing, and the outer peripheral fine grinding wheel 72 is a soft resin bond grindstone to alleviate the impact such as runout. Therefore, there is no damage such as scratches on the machined surface, and the chirico produced by grinding is discharged like an arrow, does not fall on the machined surface, and causes scratches and streaks due to scratches on the machined surface. There is no.

FIG. 11 is a side view showing the end surface of the work material processed by the above method for manufacturing a chamfered substrate, and shows the state of the streaks after grinding with the outer peripheral fine grinding wheel 72, which is a resin grindstone, with diagonal lines. .. The width of the grinding groove 74 is sufficiently large with respect to the thickness of the work material (board, work), and the grinding groove 74 is brought into contact with the work material at an oblique angle of 6 to 10 °. The work was chamfered so that only one side was in contact with the work and the other side was not touched. In practice, grinding with the upper surface in contact was performed once with respect to the entire circumference of the end face of the material to be processed, then the lower surface was brought into contact with the surface, and another round was performed for a total of two rounds of polishing and chamfering. ..

In the conventional chamfering by helical grinding, good chamfering was not possible due to the strong contact of only one of the upper and lower surfaces of the grinding groove of the grindstone with the work material having corners and straight parts. As described above, the central portion C in the thickness direction becomes a peculiar streak of helical grinding according to the angle at which the grindstone is tilted, and the shape is not deformed with good surface roughness.

In addition, both the upper and lower ends are symmetrical in angle and size, the widths of Tu and Td are even in the figure, and the streaks and angles due to helical grinding of the corners of the end face of the work material at the ends of the grinding groove, The direction is different by the amount that the end of the grinding groove hits, which is clearly visible.

Further, as smartphones and tablets have become thinner and lighter, conventionally, a glass substrate has been cut to a predetermined size, then chemically strengthened, and then masking printing is performed to form a sensor electrode. .. On the other hand, according to the above-mentioned method for manufacturing a chamfered substrate, even if the large glass substrate is chemically strengthened, masked printing and sensor electrode formation are formed, and then cutting and chamfering are performed. That is, good processed surface roughness can be obtained even when the end face is not chemically strengthened, and the occurrence of microcracks can be suppressed. As a result, the production efficiency is extremely improved, and a practically sufficient end face strength can be obtained.

Further, not only the surface roughness and the symmetry of the shape, but also the grinding groove is corrected once (tooling), and then the grinding ability is lowered, the predetermined outer peripheral surface width, the outer peripheral angle, and the outer peripheral shape are not satisfied continuously. The number of sheets that can be processed can also be increased. Further, when the tooling of the outer peripheral fine grinding wheel 72, which is a resin grindstone, is repeated and the chamfering process is continued, the number of sheets that can be processed before the resin grindstone becomes smaller than the 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, but the helical grinding may be similarly performed twice during rough grinding, that is, when the outer peripheral rough grinding wheel 69 is used. .. According to this, during fine grinding, wear, clogging, and deformation of the groove shape of the grinding groove 74 of the outer peripheral fine grinding wheel 72 can be prevented, and better chamfering can be performed.

Further, the upper part of the end face of the work material is ground so as to make one round in the grinding groove 74 over the entire circumference (grinding of the upper part), and then the grinding wheel 69 or 72 is relative to the thickness direction of the work material. It was decided to grind the lower part once more (grinding the lower part), but the order may be reversed, and the upper surface slope which is the end part of the grinding groove 74 is on the upper part and the lower part of the end face of the work material. Grinding of the central portion where neither the 72u nor the lower surface slope 72d is applied may be performed separately.

FIG. 12 shows the grinding of the central portion (a), the grinding of the upper portion (b), and the grinding of the lower portion (c). In the central grinding (a), when the chuck table 73 is sent toward the outer peripheral refined spindle 71, the upper surface slope 72u at the upper right end of the grinding groove 74 and the lower surface slope 72d at the lower left end are both glass panels. Machining is started without abutting on the upper and lower surfaces of W, 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. When the grinding groove 74 tilts the apparent thickness y0 of the glass panel W (see FIG. 6), that is, the grinding groove 74 of the outer peripheral grinding wheel 72 by an angle θ, the diameter of the grinding groove 74 is D, and the glass panel which is the work material. It is at least 20 to 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 helically ground in contact with the circumferential portion of the grinding groove 74 of the outer peripheral grinding wheel 72. When the processing point reaches the R portion of the corner, the chuck table 73 is rotated to process the R portion of the corner portion. Since the end portion of the glass panel W in the thickness direction is not ground on the upper and lower slopes (or upper and lower end portions) 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. When the circular portion as shown in 2 is the main body and there is a straight portion such as the OF portion, it is convenient to carve out the shape.

FIG. 12B shows the upper grinding, and from the state of FIG. 12A, the outer peripheral fine 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 formed. The upper surface of the glass panel W, the upper right end portion in the drawing, is brought into contact with the upper surface slope 72u of the portion. That is, the grinding wheel is lowered in the thickness direction relative to the work piece. After that, the glass panel W held on the chuck table 73 is moved in the Y-axis direction at a constant speed, and chamfering is performed by helical grinding.

FIG. 12 (c) shows the grinding of the lower portion, and from the state of FIG. 12 (b), the outer peripheral fine 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 of the grinding groove 74 is sloped. Is in contact with the lower surface of the glass panel W, the lower surface slope 72d of the lower left portion in the figure. That is, the grinding wheel is raised in the thickness direction relative to the work piece. After that, the glass panel W held on the chuck table 73 moves at a constant speed in the Y-axis direction, and chamfering is performed on the third lap following FIGS. 12 (a) and 12 (b).

In FIG. 12, the central portion grinding (a), the upper grinding portion (b), and the lower portion grinding (c) are described in this order, but the upper portion grinding (b) and the central portion grinding (c) are not limited to this. The order of a) and grinding (c) at the bottom may be arbitrary. However, if the central portion is ground (a) first, the shape can be cut out first, and then the upper grinding (b) and the lower grinding (c) can be performed more carefully and accurately. Is excellent.

Further, as the material to be processed, particularly when the circular portion as shown in FIG. 2 is the main body and there is a straight portion such as the OF portion, the central portion is ground (a), the upper portion is ground (b), and the lower portion is ground. It is not necessary to go around the outer circumference of the work piece once for each grinding (c). For example, if the circular portion is subjected to only the upper grinding (b) and the lower grinding (c), and the straight portion is subjected to the central portion grinding (a), the upper grinding (b), and the lower grinding (c), respectively. It is good, the surface roughness is good, the machining time is shortened without causing shape collapse, and the grinding groove 74 can be prevented from being worn, clogged, and deformed.

Although FIGS. 6, 7 and 12 have described the rise or fall in the thickness direction of the work material, FIG. 13 shows the relationship between the upper surface slope 72u and the lower surface slope 72d of the grinding groove 74 of the outer peripheral grinding wheel 72. The relationship between the slope of the grinding groove 74 and the chamfering angle will be described in detail. FIG. 13A shows a state in which the outer peripheral grinding wheel 72 is brought into contact with the work piece W without being tilted, and the chamfering angle coincides with the angles of the upper surface slope 72u and the lower surface slope 72d of the grinding groove 74. ..

FIG. 13 (b) shows a state in which the outer peripheral fine grinding wheel 72 is tilted for helical grinding, which is 3 to 15 °, preferably 6 to 10 °. The contact area between 72u and the upper surface of the work piece W is not significantly different from that in FIG. 13A. Therefore, as already shown in FIG. 11, the upper and lower ends (Tu and Td regions) of the work material W also have streaks in different directions due to the slope as compared with the central portion C, and the effect of helical grinding is obtained. Is sufficiently obtained, processing distortion and surface roughness are improved as much as the central part. The appearance of these three streaks is also a feature of the above embodiments.

In order to make the explanation easier to understand, the outer peripheral grinding wheel 72 is tilted based on the fact that the slope of the grinding groove 74 is matched with the chamfer angle by not tilting the outer peripheral grinding wheel 72 in FIG. 13 (a). This is shown in FIG. 13 (b). On the other hand, on the contrary, the slope may be made to match the chamfer angle of the work piece W in FIG. 13B in which the outer peripheral grinding wheel 72 is tilted. As a result, even when the amount of grinding is small at the start of processing, the contact region between the upper surface slope 72u and the upper surface of the work material W increases, and the surface roughness at both the upper and lower ends of the work material W is improved.

10 ... Machining unit, 20 ... Supply and recovery unit, 30 ... Weiha cassette, 31 ... Cassette table, 40 ... Supply and recovery robot, 50 ... Transfer arm, 60 ... Weiha feed device, 61 ... Outer peripheral fine grinding device, 62 ... Outer peripheral rough grinding Equipment, 65 ... Chuck table drive motor, 66 ... Chuck table, 67 ... Outer peripheral grinding motor, 68 ... Outer peripheral grinding spindle (rotary shaft), 69 ... Outer peripheral grinding wheel, 70 ... Outer peripheral grinding motor, 71 ... Outer peripheral grinding Grinding spindle (rotating shaft), 72 ... outer circumference fine grinding wheel, 72d ... lower surface slope, 72u ... upper surface slope, 73 ... chuck table, 74 ... grinding groove, 80 ... surface grinding machine, 81 ... precision stage, 82 ... grindstone, 83 ... Work material, 84 ... Vise, W ... Waha, glass panel, Work material, y0 ... Apparent thickness of work material

The present invention relates to a method and an apparatus for manufacturing a highly accurate chamfered substrate on the end face of various materials such as silicon, sapphire, compound, and glass, particularly a plate-shaped workpiece such as a semiconductor wafer and a glass panel. It is suitable for end face processing of a work material having a straight portion other than a circular portion.

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

Silicone is hard and brittle, and if the end face of the wafer remains sharp during slicing, it will easily crack or chip during handling such as transportation and alignment in the subsequent processing process, and fragments will damage or contaminate the wafer surface. Or something. To prevent this, the end face of the cut wafer is chamfered with a chamfering grindstone coated with diamond. At this time, it is also included to match the diameters of the outer circumferences with variations, to match the width of the orientation flat (OF), and to match the dimensions of a minute notch called a notch.

In addition, the glass substrate used for smartphones and tablets, which has been pursued to be thinner and lighter, is subjected to masking printing, sensor electrode formation, and then cutting. The generation of microcracks 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, but in this case, grinding marks in the circumferential direction are likely to occur in the chamfered portion. Therefore, it is known to perform so-called helical grinding in which, for example, a resin bond grindstone (resin grindstone) is tilted with respect to the wafer to grind the chamfered portion of the wafer.

When helical grinding is performed, not only the processing strain of the chamfered portion is reduced as compared with normal grinding, but also 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 machined, the vertical angle of the groove of the resin grindstone gradually changes, and as a result, the vertical asymmetry of the chamfered portion of the wafer is further increased. growing. Therefore, the edge of the disc-shaped tool is ground by the groove of the first grindstone in which a groove having an asymmetrical shape is formed around the groove, and the edge of the tool is formed into a groove shape that is asymmetrical in the vertical direction. A groove is formed around the second grindstone by tilting the grindstone relatively, and the wafer is tilted relative to the groove direction by the second grindstone to obtain a resin grindstone that is substantially symmetrical in the vertical direction and chamfered. It is known to finely grind a portion, and is described in, for example, Patent Document 1.

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

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

JP-A-2007-165712 Japanese Unexamined Patent Publication No. 2007-21586 Japanese Unexamined Patent Publication No. 2005-153129

In the above-mentioned prior art, the one described in Patent Document 1 requires a first grindstone in which a groove having a vertically asymmetrical shape is formed around it, and it is difficult to determine the shape thereof. In the case of a circular waiha, the same shape can be used for the entire circumference, so it can be uniquely determined. However, a waiha substrate with an OF, a rectangular or polygonal waiha with an arc at the corner, a substrate, a cover glass, etc. are circular. If there is a part and a non-circular part, not only is it more difficult, but also the change in the vertical angle of the groove of the resin grindstone becomes large at the position where the circular part shifts to the non-circular part, and the corner part, and the entire circumference is helically ground. It was extremely difficult to do. That is, at the corners of the substrate (work) having corners, only one of the upper surface and the lower surface of the groove of the grindstone was hit, and good chamfering could not be performed.

In the case described in Patent Document 2, the grinding process is complicated, and it is good when the grinding process is mainly circular and the number of non-circular portions is small, but it is difficult to apply in the case of a rectangle or a polygon.

In the case described in Patent Document 3, the grindstone must be moved relatively in the thickness direction of the wafer during chamfering. Therefore, in order to improve the accuracy of chamfering, the thickness direction of the wafer or the grindstone must be controlled. It was complicated and difficult.

An object of the present invention is to solve the above-mentioned problems of the prior art, and even a wafer substrate with OF (orifura), 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 purpose is to facilitate grinding, increase the contact area between the workpiece and the grindstone, improve the surface roughness, and improve the shape loss.

In order to achieve the above object, the present invention is a method for manufacturing a chamfered substrate in which an end surface of a plate-shaped work material having corners and straight parts is ground by a grinding groove of a grinding wheel, and is a method of manufacturing a chamfered substrate of the work material. The flat surface is attracted in the thickness direction by a chuck table smaller than the outer peripheral shape of the work material, and the rotation axis of the grinding wheel is tilted with respect to the thickness direction axis perpendicular to the flat surface of the work material. , The grinding groove is pressed against the end surface of the work material from the vertical direction to abut, the chamfered portion on the upper part of the work material comes into contact with the upper surface slope of the grinding groove, and the chamfered portion on the lower part of the work material Grinding the upper chamfered portion on the upper surface slope so as not to contact the lower surface slope of the grinding groove is continuously performed on the entire circumference including the corner portion of the end surface of the work material, and then the grinding grindstone. Is raised in the thickness direction relative to the work material so that the lower chamfered portion of the work material comes into contact with the lower surface slope and the upper chamfered part does not come into contact with the upper surface slope. The lower chamfered portion is ground on the lower surface slope continuously over the entire circumference including the corners of the end faces of the work material, or the lower chamfered portion of the work material is on the lower surface slope. To contact and grind the lower chamfered portion on the lower surface slope so that the upper chamfered portion of the work material does not come into contact with the upper surface slope, the entire circumference including the corner portion of the end surface of the work material is to be ground. After that, the grinding wheel is lowered in the thickness direction relative to the work material so that the chamfered portion of the upper part of the work material comes into contact with the upper surface slope and the lower part is chamfered. Grinding the chamfered portion of the upper portion on the upper surface slope so that the portion does not come into contact with the lower surface slope is continuously performed on the entire circumference including the corner portion of the end surface of the work material .

Further, in the above, it is preferable that the width of the grinding groove is made larger than the apparent thickness of the work material when the rotation axis of the grinding wheel is tilted.

Further, in the above, the upper part of the end face of the work material is ground by the grinding groove, and then the grinding wheel is raised relative to the work material in the thickness direction to grind or grind again. It is preferable to grind the lower part of the end face of the work material in the grinding groove, and then lower the grinding wheel in the thickness direction relative to the work material to grind again.

Further, in the above, the upper part or the lower part of the end face of the work material is ground so as to make one round in the grinding groove over the entire circumference, and then the grinding wheel is placed relative to the work material. It is preferable to raise or lower in the thickness direction and further grind one round.

Further, in the above, it is preferable to incline the rotation axis of the grinding wheel by 3 to 15 °.

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

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

Further, according to the present invention, in a chamfering device for chamfering the end surface of a plate-shaped work material having corners and straight parts with a grinding groove of a grinding wheel, the flat surface of the work material is adsorbed in the thickness direction. The rotation axis is tilted with respect to the chuck table smaller than the outer peripheral shape of the work material and the axis in the thickness direction perpendicular to the plane of the work material, and the grinding groove is perpendicular to the end face of the work material. The chamfered portion on the upper part of the work material comes into contact with the upper surface slope of the grinding groove, and the chamfered part on the lower part of the work material is the lower surface slope of the grinding groove. The chamfered portion of the upper portion is continuously ground on the upper surface slope so as not to come into contact with the material, and the entire circumference including the corner portion of the end surface of the work material is continuously formed. On the other hand, the chamfered portion of the lower portion of the work material is relatively raised in the thickness direction so that the chamfered portion of the lower portion of the work material comes into contact with the lower surface slope and the chamfered portion of the upper portion does not contact the upper surface slope. Is continuously ground on the lower surface of the work material over the entire circumference including the corners of the end faces of the work material, or the chamfered portion of the lower part of the work material comes into contact with the lower surface of the work material to be processed. Grinding the lower chamfered portion on the lower surface slope so that the upper chamfered portion of the material does not come into contact with the upper surface slope is continuously performed on the entire circumference including the corner portion of the end surface of the work material, and then. The grinding wheel is lowered in the thickness direction relative to the work material so that the upper chamfered portion of the work material comes into contact with the upper surface slope, and the lower chamfered portion is brought to the lower surface slope. Grinding the chamfered portion of the upper portion on the upper surface slope without contact is continuously performed on the entire circumference including the corner portion of the end surface of the work material .

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

Further, in the above, the upper part of the end face of the work material is ground by the grinding groove, and then the grinding wheel is raised relative to the work material in the thickness direction to grind again. Alternatively, it is preferable to grind the lower part of the end face of the work material in the grinding groove, and then lower the grinding wheel in the thickness direction relative to the work material to grind again.

Further, in the above, the upper part or the lower part of the end face of the work material is ground so as to make one round in the grinding groove over the entire circumference, and then the grinding wheel is relative to the work material. It is preferable to raise or lower the thickness in the thickness direction and further grind one round.

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

Further, in the above, it is preferable that the end face of the work piece is ground by grinding the upper part of the end face, grinding the central part, and grinding the lower part, respectively.

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 loss can be reduced.

Top view showing the main part of the chamfering apparatus which concerns on one Embodiment of this invention Perspective view showing the configuration of the processed portion in one embodiment (the work material is a circular portion and a straight portion). Top view in FIG. Perspective view showing the configuration of the processed portion in one embodiment (the material to be processed is mainly a straight portion). Top view in FIG. Top view explaining the contact between the work material and the upper and lower ends of the grinding wheel Perspective view showing helical grinding of end face processing of conventional plate material Side view explaining the difference between the conventional grinding and the grinding by one embodiment A side view showing an end face of a work material processed by the method for manufacturing a chamfered substrate according to an embodiment. Side view showing a manufacturing how the chamfering substrate according to another embodiment A side view showing details of the grinding wheel and the material to be processed according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The invention is not limited by this embodiment, and the components in the embodiment 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 device according to an embodiment of the present invention. The chamfering device mainly has a supply / recovery unit 20 and a processing unit 10, and is further composed of a pre-alignment unit, a cleaning unit, a post-measurement unit, a transport unit, and the like, although not shown.

The wafer processing process is performed in the order of slicing → chamfering → wrapping → etching → donor killer → fine chamfering, and various cleanings are used to remove stains between the processes. Silicone is hard and brittle, and if the end face of the wafer remains sharp during slicing, it will easily crack or chip during handling such as transportation and alignment in the subsequent processing process, and fragments will damage or contaminate the wafer surface. Or something. In order to prevent this, in the chamfering process, the end face of the cut wafer is chamfered with a chamfering grindstone coated with diamond.

The chamfering step may be performed after the wrapping step. At this time, the diameters of the outer circumferences that vary are matched, the width of the orientation flat (OF) is matched, and the dimensions of a minute notch called a notch are matched.

The supply / recovery unit 20 supplies the chamfered wafer W from the wafer cassette 30 to the processing unit 10 and collects the chamfered wafer into the wafer cassette 30. This operation is performed by the supply / recovery robot 40. The wafer cassette 30 is set on the cassette table 31 and contains a large number of wafers W to be chamfered. The supply / recovery robot 40 takes out 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 is provided with a 3-axis rotary type transfer arm 50, and the transfer arm 50 is provided with a suction pad (not shown) on the upper surface thereof. The transfer arm 50 holds the wafer W by vacuum suctioning the back surface of the wafer W with a suction pad. That is, the transport arm 50 of the supply / recovery robot 40 can move back and forth, move up and down, and turn while holding the wafer W, and transports the wafer W by combining these operations.

The processing portion 10 is arranged on the front portion of the wafer chamfering device, and performs all processing of the outer peripheral chamfering of the wafer W, that is, from roughing to finishing. The processing section 10 includes a wafer feed device 60, an outer peripheral rough grinding device 62, a transfer arm 63 for transporting the wafer W, and an outer peripheral fine grinding device 61.

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

The outer peripheral rough grinding device 62 is arranged at a position separated by a predetermined distance in the Y-axis direction with respect to the chuck table 66 of the wafer feeding device 60. The 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 and rotates. The outer peripheral rough grinding spindle 68 is configured to be movable in each of the front-rear direction (Y-axis direction) and the up-down direction (Z-axis direction) by being driven by a driving means (not shown).

An outer peripheral rough grinding wheel 69 that roughens (roughly grinds) the outer periphery of the wafer W is mounted on the outer 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 (total shape grindstone), and by pressing the outer periphery of the wafer W against these grooves, the outer periphery of the wafer W is roughened (the outer circumference of the wafer W is roughened. Rough grinding).

The outer peripheral fine grinding device 61 is arranged at a position separated by a predetermined distance in the X-axis direction from the chuck table 66 of the wafer feed device 60. The outer peripheral fine grinding device 61 has an outer peripheral fine grinding spindle 71 that is driven by an outer peripheral fine grinding motor 70 and rotates. The outer peripheral refined spindle 71 is configured to be movable in each of the left-right direction (X-axis direction) and the up-down direction (Z-axis direction) by being driven by a driving means (not shown). An outer peripheral fine grinding wheel 72 that finishes (finely grinds) the outer periphery of the wafer W is mounted on the outer peripheral fine grinding spindle 71, and serves as a rotation axis thereof.

The outer peripheral grinding wheel 72 has a groove for outer peripheral grinding formed on the outer peripheral surface thereof (total shape grindstone), and the outer periphery of the wafer W is finished by pressing the outer periphery of the wafer W against the groove.

At this time, the wafer is subjected to helical grinding in a state where the rotation axis of the outer peripheral refined spindle 71 is tilted 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. Finish the chamfering of the outer circumference of W.

As a result, the movement direction of the abrasive grains intersects with the movement direction of the outer circumference of the wafer W, and the contact area is increased, so that the wear of the grindstone can be suppressed and the shape of the outer circumference can be reduced. The roughness of the machined surface (ground surface) is improved.

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

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

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

When the alignment operation is completed, the outer peripheral rough grinding motor 67 is driven. Next, grinding (roughing) with the outer peripheral 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 wheel 69, for example, a metal bond grindstone having diamond abrasive grains having a diameter of 202 mm and having a particle size of # 800 can be used. Further, the outer peripheral rough grinding spindle 68 is a spindle driven by a built-in motor using ball bearings, and is rotated at a predetermined rotation speed, for example, a rotation speed of 8,000 rpm.

When the outer peripheral rough grinding spindle 68 is sent toward the chuck table 66, the outer periphery of the wafer W comes into contact with the grinding groove for outer peripheral rough grinding formed on the outer peripheral rough grinding wheel 69, and the outer peripheral portion of the wafer W is rough ground. Grinding is performed by the grindstone 69, and roughing of the outer peripheral chamfer of the wafer W is started.

After the rough machining by the outer peripheral rough grinding wheel 69 is started, since the wafer W in FIG. 2 is circular at first, the wafer W held by the chuck table 66 starts rotating in the arrow direction at a constant speed. When this rotation angle, that is, the OF portion where the machining point is a straight portion is reached, the feed amount in the direction toward the chuck table 66, which is the Y direction of the outer peripheral rough grinding spindle 68, is increased, and the outer peripheral rough grinding spindle 68 is X. Process the straight part by moving it linearly in the direction. After that, when the machining of the straight portion is completed, the plate-shaped wafer W held by the chuck table 66 is rotated again in the direction of the arrow at a constant speed, the remaining circular portion is ground, and the rough machining by the outer peripheral rough grinding wheel 69 is performed. To finish.

Next, the finishing process by the outer peripheral fine grinding wheel 72 is performed in the same manner. As the outer peripheral fine grinding wheel 72, a resin bond grindstone having diamond abrasive grains is suitable. Further, the outer peripheral chamfer of the waha W is performed in a state where the rotation axis of the outer circumference refined spindle 71 is tilted by 3 to 15 °, preferably 6 to 10 ° in the tangential direction of the outer circumference of the waha W with respect to the rotation axis of the chuck table 66. Finishing is done.

Further, the chamfering groove of the outer peripheral fine grinding wheel 72 is formed by a truer, but detailed description thereof will be omitted. Further, as the outer peripheral rough grinding wheel 69, for example, one in which metal powder such as Fe, Cr, Cu or the like is used as a main component and diamond abrasive grains are mixed and formed is used. As the material of the turret, a material capable of grinding the outer peripheral fine grinding wheel 72 while being able to be processed by the outer peripheral rough grinding wheel 69 is adopted.

For example, it is desirable that abrasive grains made of silicon carbide are bonded with a phenol resin by adding a filler or the like as necessary, and this is formed into a disk-shaped turret. As the material of the outer peripheral fine grinding wheel 72, a grinding groove 74 can be formed around the grinding wheel by grinding with a truer, while a chamfered portion such as a silicon wafer can be finely ground by the formed polishing. For example, it is desirable that a phenol resin, an epoxy resin, a polyimide resin, a polystyrene resin, a polyethylene resin or the like is used as a main component, and a diamond abrasive grain or a cubic boron nitride abrasive grain is mixed and molded.

Further, as the outer peripheral fine grinding wheel 72, for example, a resin bond grindstone having diamond abrasive grains having a diameter of 50 mm and having a particle size of # 3000 is used. The outer peripheral Seiken spindle 71 is a built-in motor-driven spindle that uses air bearings and is rotated at a rotation speed of 35,000 rpm.

FIG. 4 is a perspective view showing the configuration of the processed portion when the material to be processed is not circular but rectangular, and FIG. 5 is similarly a plan view. When the work material is not circular but rectangular, as shown in FIGS. 4 and 5, the processing of the straight portion is mainly performed.

As smartphones and tablets become thinner and lighter, glass substrates, cover glass, sapphire, and ceramics are used for the surface, and end face strength becomes important. In mirror grinding, chipping due to abrasive grains is suppressed and good surface roughness is achieved. Is required. Chamfering processing quality, processed surface roughness, occurrence of microcracks, etc. directly affect the end face strength of the glass substrate.

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

When the outer peripheral fine grinding 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 peripheral fine grinding groove, which is a chamfering processing groove formed on the outer peripheral grinding grindstone 72. , The outer peripheral portion of the glass panel W is helically ground by the outer peripheral fine grinding grind 72, and the outer peripheral chamfering process of the glass panel W is started. Since the glass panel W in FIGS. 4 and 5 is rectangular after the machining by the outer peripheral grinding wheel 72 is started, the glass panel W held by the chuck table 73 starts moving at a constant speed in the Y-axis direction. When the machining point reaches the corner portion, the chuck table 73 moves in the Y-axis direction while rotating 90 ° to machine the next straight portion. Hereinafter, the entire outer circumference of the glass panel W will be processed in the same manner.

Further, the grinding wheel is used by impregnating a chamfering wheel material having a porous surface with a lubricant together with a saturated fatty acid solution and drying the surface to obtain a lubricant-impregnated grindstone. It is desirable to do. As a result, the lubricant is reliably supplied to the cutting point of the grindstone, and the cutting point temperature can be lowered to a predetermined temperature or lower. Moreover, since the coolant is water, environmental pollution by the coolant can be prevented. Further, in the waiha chamfering device, since the abrasive stone is impregnated with the lubricant, the lubricant can be supplied to the cutting point for a long period of time, and since the coolant is water, low temperature and environment-friendly processing becomes possible.

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

Specifically, for the size of the chuck table 73, 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, Q = (1). It is preferable to set .3 to 1.7) P, more preferably Q = 1.5P, from the viewpoint of fixing and grinding by adsorption of the glass panel W. That is, while avoiding the influence of deformation, bending, and distortion of the glass panel W on the processing accuracy, the material to be processed and the glass panel W itself are slightly elastically deformed during processing, and the outer peripheral fine grinding wheel 72 is a soft resin bond grindstone. Coupled with that, the impact such as the runout is mitigated. The same applies to the Y-axis direction, and it is desirable that N = (1.3 to 1.7) H in FIG. 5, and more preferably N = 1.5H. That is, the shape of the chuck table 73 is smaller than the outer peripheral shape of the work material, and it is desirable that the shape of the chuck table 73 is 0.6 to 0.8 times larger than the planar shape of the glass panel W in both vertical and horizontal directions. The shape of the rectangular glass panel W is preferably about 120 mm × 60 mm in length × 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 refined spindle 71 is tilted 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 finely ground on the outer circumference. It abuts on the grinding groove 74 of the grindstone 72 at this angle θ, and the moving direction of the abrasive grains intersects with the moving direction of the glass panel W. Further, if the inclination angle is too large, it is not preferable in terms of an increase in grinding resistance, chipping of vertical corners on the end face, scratches, and the like.

Width y of the grinding groove 74 of the outer ShuTadashi grinding wheel 72, the grinding groove 74 of the outer periphery fine grinding wheel 72 when the inclined angle theta, from the position where the upper end portion of the grinding groove 74 is in contact with the upper face of the workpiece W the distance to the position where the lower surface of the workpiece W is not closest but abutting the lower end of the grinding groove 74, i.e., the apparent thickness of the workpiece when tilting the grinding groove 74 angle theta, the left end from the right end portion Y> y0, which is wider than the dimensions y0 up to. y0 is approximately Dtanθ + t / cosθ, where D is the diameter of the grinding groove 74 and t is the thickness of the workpiece W. As a method of widening the width of the grinding groove 74, the groove for transfer at the time of tooling may be widened in advance, or the tooling at the time of tooling is moved up and down in the Z-axis direction to widen the grinding groove 74. You may.

Next, the machining procedure of helical grinding will be described below.
With reference to FIG. 10, when the outer peripheral refined spindle 71 is sent toward the chuck table 73, the upper surface slope 72u of the upper right end portion of the grinding groove 74 comes into contact with the upper surface and the upper right end portion of the glass panel W for processing. Is started, 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.

The lower surface of the glass panel W does not come into contact with the lower surface of the glass panel W because the grinding groove 74 is wider than the apparent thickness of the glass panel W. The central portion and the main portion of the glass panel W in the thickness direction are helically ground in contact with the circumferential portion of the grinding groove 74 of the outer peripheral grinding wheel 72. When the processing point reaches the corner radius portion of the glass panel W, the chuck table 73 rotates to process the corner radius portion. At this time, it is the same as grinding a circular portion, and the contact area becomes smaller, so that the contact on the upper slope of the grinding groove 74 becomes weaker, and the central portion in the thickness direction is mainly ground. Hereinafter, in the same manner, processing is performed until the outer circumference of the glass panel W makes one round.

In that the machining of the upper SL has one turn, increase the outer ShuTadashi grinding wheel 72 in the Z-axis direction, or the chuck table 73 is moved down to the Z-axis direction, the lower surface of the lower surface slopes glass panel W of the grinding groove 74, the left The lower surface slope 72d of the lower end is brought into contact with the lower surface. That is, the grinding wheel is raised in the thickness direction relative to the work piece. After that, the glass panel W held on the chuck table 73 moves at a constant speed in the X-axis direction to chamfer the second lap.

The upper surface of the glass panel W does not come into contact with the upper surface of the glass panel W because the grinding groove 74 is wider than the apparent thickness of the glass panel W. The central portion and the main portion of the glass panel W in the thickness direction are helically ground in contact with the circumferential portion of the grinding groove 74 of the outer peripheral grinding wheel 72.

As described above, the grinding groove 74 of the outer peripheral fine grinding grindstone 72 is tilted at an angle θ to come into contact with the glass panel W so that the moving direction of the abrasive grains intersects with the moving direction of the glass panel W. Make the width of the grinding groove 74 of the outer peripheral fine grinding grindstone 72 wider than the apparent thickness of the work piece when the outer peripheral fine grinding grindstone 72 is tilted by an angle θ with respect to the work material. By moving up and down in the axial direction, it becomes possible to apply helical grinding to chamfering a straight portion such as OF or a material such as a rectangle or a polygon. As a result, the surface roughness and processing distortion of the end face are reduced, and even a high-count grindstone can be used for a long time.

Here, the present inventor increases the angle of θ so that the upper right end of the upper surface of the glass panel W abuts on the upper surface slope 72u, and the lower surface slope 72d hits the lower left lower end of the lower surface of the glass panel W. An evaluation was carried out in which grinding was performed so as to be in contact with each other. Then, when grinding the R at the corner of the glass panel W, it was found that the glass panel W always comes into contact with only one of the upper surface slope 72u and the lower surface slope 72d. For this reason, it has been found that at the corners of the glass panel W, there is always a portion on either the upper surface or the lower surface where grinding is insufficient.

Therefore, the present inventor has a relationship between θ , y, and the thickness t of the glass panel W when performing helical polishing, “only one of the upper surface and the lower surface of the glass panel W is the end portion (upper surface) of the grinding groove 74. It has been found that θ, y, t must be selected so that it touches the slope 72u or the lower slope 72d) and the other does not touch the end ”(Condition 1). Therefore, if any of these parameters is determined, the above condition 1 must be satisfied by adjusting the changeable parameter. At that time, in the range satisfying the condition 1, Narube rather y 0 is found to be more preferable a value close to y. As a result, most of the grinding groove 74 can be used, so that the life of the grindstone is extended.

FIG. 6 is a plan view for explaining the difference in contact between the outer peripheral fine grinding grindstone 72 and the grinding groove 74 at the upper and lower ends of the glass panel W in the thickness direction 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 precision grinding wheel 72 and the straight work W1 is not only larger than the contact area between the cylindrical portion and the circular work W2, but also the upper and lower end slopes 72u or the lower surface slope 72d of the upper and lower ends of the grinding groove 74. The contact area L of the linear work W1 with is larger than the contact area M of the circular work W2.

Therefore, not only the grinding resistance of the straight work W1 is larger than the grinding resistance of the circular work W2, but also when the width of the grinding groove 74 in the thickness direction is chamfered according to the circular work W2, the straight work W1 can be chamfered. become unable. Further, even if the grinding groove 74 is created so that the circular work W2 can be chamfered vertically symmetrically, the shapes of the upper and lower surfaces will be different if the grinding groove 74 is chamfered with respect to the straight work W1.

FIG. 7 shows an example of helical grinding by an axial tilting method in which one axis is added to the surface grinding machine 80 as opposed to the conventional end face machining of a plate material. As shown in FIG. 7 , the precision stage 81 is arranged at an inclination angle α so that the work piece 83 passes through the lowest point of the grindstone 82. The grindstone 82 is wider than the work piece 83, and both sides are fixed close to the machined surface by the vise 84.

In this method, as shown in FIG. 8 (a), the workpiece 83 is vice 84, that it is firmly fixed, from such a point that the rotation shaft of the grinding wheel 82 is machined surface and the horizontal, the grinding wheel 82 is It is pressed as shown by the arrow V, and the runout of the grindstone 82 causes an impact on the work piece 83, causing damage to the machined surface. In addition, since the ground chirico falls on the machined surface, scratches due to the chirico and streaks due to scratches are generated on the machined surface.

On the other hand , in the present invention, the grinding groove 74 of the outer peripheral grinding wheel 72 is tilted by an angle θ with respect to the work piece W. Further, a flat surface of the glass panel W is placed on the chuck table 73, and the surface of the chuck table 73 is depressurized by an air compressor, a blower, or the like to attract and fix the glass panel W. For Figure 8 which holds the glass panel W is adsorbed in the vertical direction to overhang from the chuck table 73 (b) is a grinding groove 74 of the outer periphery fine grinding wheel 72 abuts perpendicularly to the processing surface, the outer peripheral seminal The pressing force of the grinding wheel 72 works as shown by the arrow H.

Therefore, the material to be processed, for example, the glass panel W itself is slightly elastically deformed during processing, and the outer peripheral fine grinding wheel 72 is a soft resin bond grindstone to alleviate the impact such as runout. Therefore, there is no damage such as scratches on the machined surface, and the chirico produced by grinding is discharged like an arrow, does not fall on the machined surface, and causes scratches and streaks due to scratches on the machined surface. There is no.

FIG. 9 is a side view showing the end surface of the work material processed by the above method for manufacturing a chamfered substrate, and shows the state of the streaks after grinding with the outer peripheral fine grinding wheel 72, which is a resin grindstone, with diagonal lines. .. The width of the grinding groove 74 is sufficiently large with respect to the thickness of the work material (board, work), and the grinding groove 74 is brought into contact with the work material at an oblique angle of 6 to 10 °. The work was chamfered so that only one side was in contact with the work and the other side was not touched. In practice, grinding with the upper surface in contact was performed once with respect to the entire circumference of the end face of the material to be processed, then the lower surface was brought into contact with the surface, and then one round was performed for a total of two rounds of polishing and chamfering. ..

In the conventional chamfering by helical grinding, good chamfering was not possible due to the strong contact of only one of the upper and lower surfaces of the grinding groove of the grindstone with the work material having corners and straight parts. As described above, the central portion C in the thickness direction becomes a peculiar streak of helical grinding according to the angle at which the grindstone is tilted, and the shape is not deformed with good surface roughness.

In addition, both the upper and lower ends are symmetrical in angle and size, the widths of Tu and Td are even in the figure, and the streaks and angles due to helical grinding of the corners of the end face of the work material at the ends of the grinding groove, The direction is different by the amount that the end of the grinding groove hits, which is clearly visible.

Further, as smartphones and tablets have become thinner and lighter, conventionally, a glass substrate has been cut to a predetermined size, then chemically strengthened, and then masking printing is performed to form a sensor electrode. .. On the other hand, according to the above-mentioned method for manufacturing a chamfered substrate, even if the large glass substrate is chemically strengthened, masked printing and sensor electrode formation are formed, and then cutting and chamfering are performed. That is, good processed surface roughness can be obtained even when the end face is not chemically strengthened, and the occurrence of microcracks can be suppressed. As a result, the production efficiency is extremely improved, and a practically sufficient end face strength can be obtained.

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

Has been described as a helical grinding using an outer ShuTadashi grinding wheel 72, during rough grinding, i.e., may also be performed helical grinding to 2 weeks in the same manner when using outer periphery rough grinding 69. According to this, during fine grinding, wear, clogging, and deformation of the groove shape of the grinding groove 74 of the outer peripheral fine grinding wheel 72 can be prevented, and better chamfering can be performed.

Further, the upper part of the end face of the work material is ground so as to make one round in the grinding groove 74 over the entire circumference (grinding of the upper part), and then the grinding wheel 69 or 72 is relative to the thickness direction of the work material. It was decided to grind the lower part once more (grinding the lower part), but the order may be reversed, and the upper surface slope which is the end part of the grinding groove 74 is on the upper part and the lower part of the end face of the work material. Grinding of the central portion where neither the 72u nor the lower surface slope 72d is applied may be performed separately.

Figure 10 shows the cutting Lab central portion. Grinding is the central portion, when the chuck table 73 is sent toward the periphery fine Lab spindle 71, both the lower surface slopes 72d of the upper surface slopes 72u and left lower ends of the upper right end of the grinding groove 74 of the glass panel W Machining is started without contacting the upper and lower surfaces, 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. Grinding grooves 74, apparent thickness y 0 of the glass panel W, that is, when grinding grooves 74 of the outer periphery fine grinding wheel 72 is inclined an angle theta, the thickness of the diameter of the grinding groove 74 D, the glass panel W is a workpiece It is at least 20 to 30% wider than the thickness considering both t and t.

The central portion and the main portion of the glass panel W in the thickness direction are helically ground in contact with the circumferential portion of the grinding groove 74 of the outer peripheral grinding wheel 72. When the processing point reaches the R portion of the corner, the chuck table 73 is rotated to process the R portion of the corner portion. Since the end portion of the glass panel W in the thickness direction is not ground on the upper and lower slopes (or upper and lower end portions) 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. When the circular portion as shown in 2 is the main body and there is a straight portion such as the OF portion, it is convenient to carve out the shape.

From the state of FIG. 10, the outer peripheral fine 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 surface of the glass panel W is on the upper right slope 72u of the upper right end of the grinding groove 74, and the upper right in the figure. Bring the ends into contact. That is, the grinding wheel is lowered in the thickness direction relative to the work piece. After that, the glass panel W held on the chuck table 73 is moved in the Y-axis direction at a constant speed, and chamfering is performed by helical grinding.

Increasing the outer ShuTadashi grinding wheel 72 in the Z-axis direction, or the chuck table 73 is lowered in the Z axis direction, the lower surface slopes of the grinding groove 74, the lower surface of the glass panel W, the lower surface slopes 72d of the left lower portion in FIG person Try to touch. That is, the grinding wheel is raised in the thickness direction relative to the work piece. After that, the glass panel W held by the chuck table 73 moves at a constant speed in the Y-axis direction to chamfer the third lap.

Grinding Hisashi Naka portion (a), top grinding (b), has been described in the order of the lower portion of the grinding (c), without being limited thereto, the upper portion of the grinding (b), the central portion grinding (a), The order of grinding (c) at the bottom may be arbitrary. However, if the central portion is ground (a) first, the shape can be cut out first, and then the upper grinding (b) and the lower grinding (c) can be performed more carefully and accurately. Is excellent.

Further, as the material to be processed, particularly when the circular portion as shown in FIG. 2 is the main body and there is a straight portion such as the OF portion, the central portion is ground (a), the upper portion is ground (b), and the lower portion is ground. It is not necessary to go around the outer circumference of the work piece once for each grinding (c). For example, if the circular portion is subjected to only the upper grinding (b) and the lower grinding (c), and the straight portion is subjected to the central portion grinding (a), the upper grinding (b), and the lower grinding (c), respectively. It is good, the surface roughness is good, the machining time is shortened without causing shape collapse, and the grinding groove 74 can be prevented from being worn, clogged, and deformed.

FIG. 11 shows details of the relationship between the upper surface slope 72u and the lower surface slope 72d of the grinding groove 74 of the outer peripheral grinding wheel 72, and describes the relationship between the slope of the grinding groove 74 and the chamfering angle. FIG. 11 shows a state in which the outer peripheral fine grinding wheel 72 is brought into contact with the work piece W without being tilted, and the chamfering angle coincides with the angles of the upper surface slope 72u and the lower surface slope 72d of the grinding groove 74.

To perform the helical grinding angles by tilting the periphery fine grinding wheel 72, 3 to 15 °, preferably because it is 6 to 10 °, if the processing is slightly starts, the upper surface slopes 72u and the workpiece W contact area between the upper surface of FIG. 11 and there is no big difference. Therefore, as already shown in FIG. 9 , the upper and lower ends (Tu and Td regions) of the work material W also have streaks in different directions due to the slope as compared with the central portion C, and the effect of helical grinding is obtained. Is sufficiently obtained, processing distortion and surface roughness are improved as much as the central part. The appearance of these three streaks is also a feature of the above embodiments.

Incidentally, for ease of explanation, by not tilting the periphery fine grinding wheel 72 of Figure 11, the slope of the ground grooves 74 can be equal to the bevel angle. On the other hand, conversely, the outer peripheral grinding wheel 72 may be tilted so that the slope matches the chamfer angle of the work piece W. As a result, even when the amount of grinding is small at the start of processing, the contact region between the upper surface slope 72u and the upper surface of the work material W increases, and the surface roughness at both the upper and lower ends of the work material W is improved.

10 ... Machining unit, 20 ... Supply and recovery unit, 30 ... Weiha cassette, 31 ... Cassette table, 40 ... Supply and recovery robot, 50 ... Conveyor arm, 60 ... Weiha feed device, 61 ... Outer peripheral fine grinding device, 62 ... Outer peripheral rough grinding Equipment, 65 ... Chuck table drive motor, 66 ... Chuck table, 67 ... Outer peripheral grinding motor, 68 ... Outer peripheral grinding spindle (rotary shaft), 69 ... Outer peripheral grinding wheel, 70 ... Outer peripheral grinding motor, 71 ... Outer peripheral grinding Grinding spindle (rotary axis), 72 ... outer circumference fine grinding wheel, 72d ... lower surface slope, 72u ... upper surface slope, 73 ... chuck table, 74 ... grinding groove, 80 ... surface grinding machine, 81 ... precision stage, 82 ... grindstone, 83 ... Work material, 84 ... Vise, W ... Waha, glass panel, work material

Claims (13)

A method for manufacturing a chamfered substrate that grinds the end face of a plate-shaped work piece with a grinding groove of a grinding wheel.
The flat surface of the work material is attracted in the thickness direction by a chuck table smaller than the outer peripheral shape of the work material.
The rotation axis of the grinding wheel is tilted with respect to the axis in the thickness direction perpendicular to the plane of the work material, and the grinding groove is pressed against the end face of the work material from the vertical direction to abut.
The upper part or the lower part of the end face of the work material is ground by the grinding groove,
After that, a method for manufacturing a chamfered substrate, which comprises raising or lowering the grinding wheel in the thickness direction relative to the material to be processed and grinding again. The 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 made larger than the apparent thickness of the work material when the rotation axis of the grinding wheel is tilted. The method for manufacturing a chamfered substrate according to claim 1 or 2.
The upper part of the end face of the work material is ground by the grinding groove, and then the grinding wheel is raised in the thickness direction relative to the work material and ground again.
Alternatively, the lower portion of the end face of the work material is ground in the grinding groove, and then the grinding wheel is lowered relative to the work material in the thickness direction and ground again. Manufacturing method of chamfered substrate. The method for manufacturing a chamfered substrate according to any one of claims 1 to 3.
The upper or lower part of the end face of the work material is ground so as to make one round in the grinding groove over the entire circumference, and then the grinding wheel is raised in the thickness direction relative to the work material. Alternatively, a method for manufacturing a chamfered substrate, which comprises lowering the surface and grinding it once more. The method for manufacturing a chamfered substrate according to any one of claims 1 to 4.
A method for manufacturing a chamfered substrate, which comprises tilting the rotation axis of the grinding wheel by 3 to 15 °. The method for manufacturing a chamfered substrate according to claim 2.
A method for manufacturing a chamfered substrate, wherein the processing of the end face of the work material is performed by grinding the upper part of the end face of the work material, grinding the central part, and grinding the lower part, respectively. The method for manufacturing a chamfered substrate according to claim 6.
A method for manufacturing a chamfered substrate, wherein the upper grinding, the central grinding, and the lower grinding are performed so as to make one round of the end face of the work piece in the grinding groove over the entire circumference. In a chamfering device that chamfers the end face of a plate-shaped work piece with a grinding groove of a grinding wheel.
A chuck table that adsorbs the flat surface of the work material in the thickness direction and is smaller than the outer peripheral shape of the work material.
The grinding wheel that tilts the rotation axis with respect to the axis in the thickness direction perpendicular to the plane of the work material and presses the grinding groove against the end face of the work material from the vertical direction to come into contact with the grinding wheel.
The upper part or the lower part of the end face of the work material is ground by the grinding groove, and then the grinding wheel is raised or lowered in the thickness direction relative to the work material to be ground again. A chamfering device characterized by the fact that. In the chamfering device according to claim 8.
A chamfering device characterized in that the width of the grinding groove is made larger than the apparent thickness of the work material when the rotation axis of the grinding wheel is tilted. In the chamfering device according to claim 8 or 9.
The upper part of the end face of the work material is ground by the grinding groove, and then the grinding wheel is raised relative to the work material in the thickness direction and ground again, or the work material is A chamfering device characterized in that the lower portion of an end surface is ground by the grinding groove, and then the grinding wheel is lowered relative to the work piece in the thickness direction and ground again. In the chamfering device according to any one of claims 8 to 10.
The upper or lower part of the end face of the work material is ground so as to make one round in the grinding groove over the entire circumference, and then the grinding wheel is raised in the thickness direction relative to the work material. Alternatively, a chamfering device characterized in that it is lowered and further ground once. In the chamfering device according to any one of claims 8 to 11.
A chamfering device characterized in that the rotation axis of the grinding wheel is tilted by 3 to 15 °. In the chamfering device according to claim 8.
A chamfering device characterized in that the end face of the work material is ground by grinding the upper part of the end face, grinding the central part, and grinding the lower part, respectively.

Images