JP6583663B2 - Glass substrate grinding method - Google Patents

Description

  The present invention relates to a method for grinding an outer peripheral end of a disk-shaped glass substrate by rotating a grinding tool.

  In recent years, a disk-shaped glass substrate is sometimes used as a support for supporting a semiconductor wafer in a back grinding process of the semiconductor wafer. In the manufacturing process of such a disk-shaped glass substrate, an orientation flat or a notch is formed at the outer peripheral end. And it is customary to perform chamfering such as R chamfering and C chamfering on the formed orientation flat and notch.

  Here, not a disk-shaped glass substrate but a semiconductor wafer is to be processed, a method of forming a notch at the outer peripheral edge of the semiconductor wafer with a grinding tool, and grinding the formed notch An example of a method for chamfering the notch is disclosed in Patent Document 1. In this method, the notch is ground by rotating a grinding tool around an axis extending parallel to the main surface (front and back surfaces) of the semiconductor wafer.

JP-A-2-180554

  However, when the above method, which assumes a semiconductor wafer with high toughness, is applied to the processing of the notch formed on the outer peripheral edge of a disk-shaped glass substrate that is a brittle material, the following problems to be solved occur. is doing. That is, when the same method is applied, the notch formed in the disk-shaped glass substrate is ground along the thickness direction of the disk-shaped glass substrate by the grinding tool. Thereby, the outer peripheral end portion in which the notch is formed is always placed in a state in which force is applied in the thickness direction from the grinding tool. As a result, there is a problem that the disc-shaped glass substrate is damaged, such as the outer peripheral edge swings unduly along the thickness direction due to the force acting from the grinding tool, and this causes cracks and chips. It was.

  Such a problem does not occur only when the above method is applied to chamfering of a notch. For example, by rotating the grinding tool in the same manner as the same method, the outer periphery of the disk-shaped glass substrate is chamfered by grinding the orientation flat formed on the outer peripheral edge of the disk-shaped glass substrate. When the above method is applied when the end portion is ground, the same problem occurs.

  An object of the present invention made in view of the above circumstances is to prevent the disk-shaped glass substrate from being damaged when the outer peripheral end of the disk-shaped glass substrate is ground by rotating a grinding tool.

  The method according to the present invention, which was devised to solve the above-mentioned problems, is a glass substrate grinding method for grinding an outer peripheral end of a disk-shaped glass substrate by rotating a grinding tool, wherein the grinding tool is It is characterized by rotating around an axis extending in the thickness direction of the glass substrate.

  According to such a method, since the grinding tool is rotated about the axis extending in the thickness direction of the disk-shaped glass substrate, the outer peripheral edge of the disk-shaped glass substrate is rotated by the grinding tool. It is ground along a direction parallel to the surface (front and back surfaces). Therefore, it can prevent as much as possible that the force which acts on an outer peripheral edge part from a grinding tool acts on the thickness direction of a disk shaped glass substrate. Thereby, during the grinding of the outer peripheral end by the grinding tool, the occurrence of a situation in which the outer peripheral end swings along the thickness direction is avoided. As a result, it becomes possible to prevent the disk-shaped glass substrate from being damaged, such as cracking or chipping.

  In the above method, the disk-shaped glass substrate is rotated about the axis extending in the thickness direction at the center thereof, and the grinding tool is rotated around the disk-shaped glass substrate against the rotation direction of the disk-shaped glass substrate. It is preferable.

  In this way, the grinding tool turns around the disk-shaped glass substrate against the direction of rotation of the disk-shaped glass substrate in the rotated state. The direction and the traveling direction of the outer peripheral end are opposite to each other. Thereby, the time required for the grinding tool to grind the outer peripheral end can be shortened.

  In the above method, after grinding the outer peripheral edge, the grinding tool or the second grinding tool that rotates about the axis extending in the thickness direction of the disk-shaped glass substrate and is different from the grinding tool is used. Then, a positioning portion obtained by removing a part of the outer peripheral end portion for positioning the disc-shaped glass substrate may be formed at the outer peripheral end portion.

  Since the positioning part is formed by removing a part of the outer peripheral edge of the disk-shaped glass substrate, the disk-shaped glass substrate is damaged when the positioning part is formed on the outer peripheral edge compared to when grinding the outer peripheral edge. It becomes easy. However, if the grinding tool or the second grinding tool is used for forming the positioning portion at the outer peripheral end, both of them rotate about the axis extending in the thickness direction of the disk-shaped glass substrate. Even when the positioning portion is formed, occurrence of a situation in which the outer peripheral end portion swings along the thickness direction is avoided. As a result, it is possible to form the positioning portion at the outer peripheral end without damaging the disk-shaped glass substrate. In addition, since the positioning portion is formed at the outer peripheral end after grinding the outer peripheral end, the positioning portion is formed after the rough shape of the disk-shaped glass substrate is determined by grinding the outer peripheral end. become. For this reason, when mass-producing the disk-shaped glass substrate which has a positioning part in an outer peripheral edge part, generation | occurrence | production of the situation which the variation in the shape produces between the disk-shaped glass substrates produced is prevented. be able to.

  In the above method, it is preferable to use a tool having a smaller diameter than the grinding tool as the second grinding tool.

  If it does in this way, at the time of grinding of the perimeter end part of a disk-like glass substrate, it will become possible to grind the perimeter end part at high speed by using the above-mentioned grinding tool with a comparatively large diameter. On the other hand, when forming the positioning part at the outer peripheral edge where the disk-shaped glass substrate is likely to be damaged, the second grinding tool with a relatively small diameter is used to prevent the disk-shaped glass substrate from being damaged as much as possible. can do. Further, it is possible to form the positioning portion with high accuracy by using the second grinding tool having a relatively small diameter.

  In the above method, when the positioning portion is a notch whose formation width gradually increases from the center side to the outer periphery side of the disk-shaped glass substrate, when the notch is formed, It is preferable to use a second grinding tool having a smaller diameter than a large one.

  In this way, since the notch is formed using the second grinding tool having a diameter smaller than the maximum width of the notch planned to be formed, the disc-shaped glass substrate is damaged as much as possible when the notch is formed. This can be prevented and the notch can be formed with high accuracy.

  In the above method, it is preferable to use a tool having a diameter of 2 mm or less as the second grinding tool.

  As the second grinding tool is used, the smaller the diameter, the higher the effect of preventing the disc-shaped glass substrate from being damaged during the formation of the positioning part and the effect of forming the positioning part with high accuracy. . If a tool having a diameter of 2 mm or less is used as the second grinding tool, both of the above effects can be suitably expressed.

  In the above method, the outer peripheral end portion is chamfered along with the grinding of the outer peripheral end portion, and the chamfering process is performed on the positioning portion when forming the positioning portion. Therefore, it is preferable to use a tool in which the shape and size of the grinding groove formed on the outer peripheral portion of the second grinding tool are the same as the shape and size of the grinding groove formed on the outer peripheral portion of the grinding tool.

  In this case, the chamfered portion between the portion excluding the positioning portion ground by the grinding tool and chamfered and the positioning portion ground by the second grinding tool and chamfered is processed. The cross-sectional shape (the cross-sectional shape when the disk-shaped glass substrate is virtually cut in the thickness direction) is substantially the same. That is, it is possible to avoid a sudden change in the cross-sectional shape between the positioning portion and a portion connected to the positioning portion. Here, when the cross-sectional shape is changing abruptly, stress concentration tends to occur when some external force is applied to the disk-shaped glass substrate, and the risk of damage to the disk-shaped glass substrate increases. However, according to this method, since the cross-sectional shape can be made substantially the same between the positioning portion and the portion connected to the positioning portion, it is possible to accurately eliminate the fear as described above. . Further, in this method, since the outer peripheral end of the disk-shaped glass substrate is ground along a direction parallel to the main surface of the disk-shaped glass substrate with a grinding tool, the front side and the back side of the disk-shaped glass substrate are It is possible to chamfer both at the same time. Thereby, the time which a chamfering process requires can be reduced significantly.

  In the above method, it is preferable that the grinding tool and the second grinding tool share the rotation axis.

  This eliminates the need to separately provide a drive source for operating the grinding tool and a drive source for operating the second grinding tool. Therefore, cost reduction and space saving can be achieved.

  In the above method, it is preferable to fix the disk-shaped glass substrate in a stationary state when forming the positioning portion.

  If it does in this way, since the positioning part is formed under the state where the disk-shaped glass substrate is made stationary, the positioning part can be formed with higher accuracy.

  In the above method, it is preferable to perform an etching process on the outer peripheral end portion after forming the positioning portion.

  When the positioning portion is formed at the outer peripheral end portion of the disk-shaped glass substrate, the strength of the outer peripheral end portion is reduced as compared with the case where the positioning portion is not formed. However, if the outer peripheral end is subjected to an etching process after the positioning portion is formed, defects such as microcracks included in the outer peripheral end can be removed. As a result, the strength of the outer peripheral end portion of the disk-shaped glass substrate can be improved.

  In the above method, after grinding the outer peripheral end portion, a scribe line is formed on the outer peripheral end portion by rolling of the scribe wheel or laser irradiation, and the orientation flat is cut along the scribe line. May be formed.

  In this way, after the outer peripheral end is ground, the orientation flat is formed at the outer peripheral end, so that after the outline shape of the disk-shaped glass substrate is determined by grinding of the outer peripheral end, the orientation flat is Will be formed. For this reason, when mass-producing a disk-shaped glass substrate having an orientation flat at the outer peripheral end, it is possible to prevent the occurrence of a situation in which the shape of the disk-shaped glass substrates varies between each other. be able to.

  According to the method for grinding a glass substrate according to the present invention, when the outer peripheral end of the disk-shaped glass substrate is ground by rotating the grinding tool, it is possible to prevent the disk-shaped glass substrate from being damaged.

It is a top view which shows the grinding method of the glass substrate which concerns on embodiment of this invention. It is a vertical side view which shows the grinding method of the glass substrate which concerns on embodiment of this invention. It is a vertical side view which expands and shows the E section in FIG. It is a vertical side view which shows the disk shaped glass substrate ground by the grinding method of the glass substrate which concerns on embodiment of this invention. It is a top view which shows the grinding method of the glass substrate which concerns on embodiment of this invention. It is a top view which shows the grinding method of the glass substrate which concerns on other embodiment of this invention.

  Hereinafter, a glass substrate grinding method according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  In the method for grinding a glass substrate according to the embodiment of the present invention, first, a chamfering process for grinding the outer peripheral end 2a of the disk-shaped glass substrate 2 and chamfering it is performed using the grinding tool 1. (FIGS. 1-3). Next, using a second grinding tool 3 different from the grinding tool 1, a notch forming step for forming the chamfered notch 4 on the outer peripheral end 2 a of the disk-shaped glass substrate 2 is performed ( FIG. 5). Finally, an etching process is performed on the outer peripheral end 2a of the disk-shaped glass substrate 2 to execute a processing step for improving the strength of the outer peripheral end 2a.

  In this glass substrate grinding method, the grinding tool 1 and the second grinding tool 3 are rotated about axes 5 and 6 extending in the thickness direction of the disk-shaped glass substrate 2 (hereinafter simply referred to as the thickness direction), respectively. Let Here, the disk-shaped glass substrate 2 to be ground in the present embodiment is a glass substrate that serves as a support for supporting the semiconductor wafer in the back grinding process of the semiconductor wafer.

  First, the chamfering process will be described.

  As shown in FIGS. 1 and 2, the disc-shaped glass substrate 2 is placed in a flat position on a table 8 that can be rotated (spinned) in the A direction about an axis 7 extending along the thickness direction. It is placed. The disc-shaped glass substrate 2 is placed on the table 8 so that the position of the center 2b of the disc-shaped glass substrate 2 coincides with the position of the axis 7 in plan view.

  The table 8 has a support portion 8a that supports the disk-shaped glass substrate 2 from below, and the support portion 8a is formed in a circle having a smaller diameter than the disk-shaped glass substrate 2 in plan view. Thereby, the outer peripheral end 2a of the disc-shaped glass substrate 2 placed on the table 8 is in a state of protruding from the outer peripheral end of the support portion 8a. The support portion 8a is formed with a large number of holes 8aa, and each of the large number of holes 8aa is connected to negative pressure generating means (for example, a vacuum pump or the like) (not shown). Thereby, the support part 8a can adsorb | suck the disk shaped glass substrate 2 because a negative pressure generation means produces | generates a negative pressure to the disk shaped glass substrate 2 through many holes 8aa.

  From the above, when the table 8 is rotated in the A direction while the disk-shaped glass substrate 2 is attracted to the support portion 8a, the disk-shaped glass substrate 2 placed on the table 8 rotates the axis 7. It rotates (spins) in the A direction without being eccentric as the center.

  The grinding tool 1 rotates (spins) in the B direction around the axis 5 as the center of rotation, and turns around the disk-shaped glass substrate 2 in the C direction against the rotation direction (A direction) of the disk-shaped glass substrate 2. Is possible. The grinding tool 1 rotates (spins) in a direction to grind the outer peripheral end 2a of the disk-shaped glass substrate 2 by a down cut method. As a modification, the grinding tool 1 may be rotated (rotated) in the direction of grinding the outer peripheral end 2a of the disk-shaped glass substrate 2 by an up-cut method.

  As shown in FIG. 3 (an enlarged view of the E portion circled in FIG. 2), the outer peripheral portion 1a of the grinding tool 1 has a number of abrasives fixed by an adhesive (for example, a metal bond). It is composed of grains. In this outer peripheral portion 1a, grinding grooves 9 for grinding the outer peripheral end portion 2a of the disc-shaped glass substrate 2 are formed in a plurality of upper and lower stages. Each grinding groove 9 includes a bottom portion 9a for grinding the outer peripheral end surface 2aa of the disc-shaped glass substrate, and a pair of side walls for grinding the upper surface 2c and the lower surface 2d of the disc-shaped glass substrate 2 respectively. Part 9b. Each grinding groove 9 is formed such that the groove width gradually increases as the grinding tool 9 moves to the outer peripheral side of the grinding tool 1. Both the bottom 9a and the side wall 9b are smoothly connected by a curved surface curved with a constant curvature. Similarly, both the side wall portion 9b and the outer peripheral end surface 1aa of the grinding tool 1 are smoothly connected by a curved surface curved with a constant curvature.

  From the above, the grinding groove formed on the outer peripheral portion 1a of the grinding tool 1 as shown in FIG. 4 by grinding the outer peripheral end portion 2a while turning around the disc-shaped glass substrate 2 by the grinding tool 1 The outer peripheral end 2a is formed in a cross-sectional shape corresponding to 9, and the chamfering process is completed.

  Next, the notch formation process will be described.

  When the chamfering process is completed, the rotation of the table-like glass substrate 2 is stopped by stopping the rotation of the table 8, and the disc-like glass substrate 2 is fixed in a stationary state. In addition, adsorption | suction of the disk shaped glass substrate 2 by the support part 8a of the table 8 is performed continuously.

  And as shown in FIG. 5, while rotating the 2nd grinding tool 3 to F direction (autorotation) and moving along the track | orbit S set beforehand, an outer periphery is carried out from the center 2b side of the disk shaped glass substrate 2. As shown in FIG. A notch 4 whose formation width gradually increases toward the side is formed in the outer peripheral end 2a. The notch 4 is formed by removing a part of the outer peripheral end 2a of the disc-shaped glass substrate 2 and, when the disc-shaped glass substrate 2 is viewed in plan, a positioning portion for determining the orientation and positioning the disc-shaped glass substrate 2 It is.

  In forming the notch 4, a tool having a diameter D2 smaller than the maximum width W of the notch 4 scheduled to be formed is used as the second grinding tool 3. The diameter D2 of the second grinding tool 3 is smaller than the diameter D1 of the grinding tool 1 used in the chamfering process, and a tool having a diameter D2 of 2 mm or less is used. Preferably, a tool having a diameter D2 of 1.5 mm or less is used as the second grinding tool 3.

  Similar to the grinding tool 1 used in the chamfering process, the outer peripheral portion 3a of the second grinding tool 3 is composed of a large number of abrasive grains fixed by an adhesive (for example, a metal bond). Furthermore, the outer peripheral part 3a is formed with a plurality of upper and lower grinding grooves for forming a notch 4 in which the outer peripheral end part 2a of the disk-shaped glass substrate 2 is ground and chamfered. The shape and dimensions of the grinding grooves are the same as the grinding grooves 9 formed on the outer peripheral portion 1 a of the grinding tool 1.

  From the above, the notch 4 having a shape following the track S is formed by grinding the outer peripheral end 2a of the disc-shaped glass substrate 2 while the second grinding tool 3 moves along the track S. The notch 4 is chamfered to complete the notch formation process.

  Finally, the processing process will be described.

  When the notch formation process is completed, the entire periphery of the outer peripheral end 2a of the disc-shaped glass substrate 2 is etched. This etching process is performed, for example, by spraying hydrogen fluoride (HF) onto the outer peripheral end 2a. When this processing step is completed, all the steps of the glass substrate grinding method according to this embodiment are completed.

  Hereinafter, main actions and effects of the above glass substrate grinding method will be described.

  According to the above glass substrate grinding method, since the grinding tool 1 and the second grinding tool 3 are rotated about the axes 5 and 6 extending in the thickness direction of the disc-shaped glass substrate 2, the disc-shaped glass substrate 2 is rotated. The outer peripheral edge 2a is ground along a direction parallel to the main surface (upper surface 2c, lower surface 2d) of the disk-shaped glass substrate 2 by the grinding tool 1 or the second grinding tool 3. Therefore, it is possible to prevent as much as possible that the force acting from the grinding tool 1 or the second grinding tool 3 to the outer peripheral end 2 a acts in the thickness direction of the disk-shaped glass substrate 2. This avoids occurrence of a situation in which the outer peripheral end 2a swings in the thickness direction during grinding of the outer peripheral end by the grinding tool 1 and during formation of the notch 4 by the second grinding tool 3. Is done. As a result, it becomes possible to prevent the disk-shaped glass substrate 2 from being damaged, such as cracking or chipping.

  Here, the grinding method of the glass substrate which concerns on this invention is not limited to the aspect demonstrated by said embodiment. In the above embodiment, the grinding tool is used for the chamfering process and the second grinding tool different from the grinding tool is used for the notch forming process. However, the chamfering process and the notch forming process are performed. The same grinding tool may be used for execution. Moreover, in said embodiment, although it becomes the aspect which forms a notch in the outer peripheral edge part of a disk shaped glass substrate as a positioning part, as shown in FIG. 6, the outer peripheral edge of the disk shaped glass substrate 2 as a positioning part It is good also as an aspect which forms the orientation flat 10 in the part 2a.

  Furthermore, in said embodiment, after performing the chamfering process which grinds the outer peripheral edge part of a disk shaped glass substrate, and performs a chamfering process, the notch formation process is performed, However, It is not this limitation. After performing the chamfering process, a scribe line is formed on the outer peripheral edge of the disk-shaped glass substrate by rolling of the scribe wheel or laser irradiation, and the orientation flat is formed by cleaving along the scribe line. May be formed. In this case, it is preferable to chamfer the formed orientation flat by grinding it with a grinding tool. In addition, as a grinding tool used for this chamfering process, the said grinding tool and the 2nd grinding tool may be used, and grinding tools other than these may be used. And also when performing this chamfering process, it is preferable to rotate a grinding tool centering on the axis line extended in the thickness direction of a disk shaped glass substrate.

  In addition, as a modification of the above embodiment, the grinding tool and the second grinding tool may share the rotation axis. That is, both grinding tools may be attached to the same rotating shaft, for example, in a state of being separated from each other in the axial direction.

DESCRIPTION OF SYMBOLS 1 Grinding tool 1a Outer peripheral part 1aa Outer peripheral end surface 2 Disc-shaped glass substrate 2a Outer peripheral end part 2aa Outer peripheral end face 2b Center 2c Upper surface 2d Lower surface 3 Second grinding tool 3a Outer peripheral part 4 Notch 5 Axis 6 Axis 7 Axis 8 Table 8a Support part 8aa Hole 9 Grinding groove 9a Bottom portion 9b Side wall portion 10 Orientation flat A Rotating direction B Rotating direction C Turning direction D1 diameter D2 diameter F Rotating direction S Orbit W Maximum width

Claims (7)

A method of grinding an outer peripheral edge of a disk-shaped glass substrate by rotating a grinding tool,
As the grinding tool, a tool that rotates about the axis extending in the thickness direction of the disk-shaped glass substrate as a rotation center,
After grinding the outer peripheral edge,
Rotating the axis extending in the thickness direction before SL disk-shaped glass substrate as the center of rotation, the and the grinding tool with a different second grinding tool,
A positioning part formed by removing a part of the outer peripheral end part for positioning the disk-shaped glass substrate is formed on the outer peripheral end part ,
The positioning portion is a notch whose formation width gradually increases from the center side of the disk-shaped glass substrate toward the outer peripheral side,
When forming the notch, using the second grinding tool having a diameter smaller than the maximum width of the notch planned to be formed,
When forming the notch, fix the disk-shaped glass substrate in a stationary state,
A method for grinding a glass substrate , wherein the notch is formed by moving the second grinding tool along a V-shaped track following the shape of the notch planned to be formed . When grinding the outer peripheral end,
The disk-shaped glass substrate is rotated with an axis extending in the thickness direction at the center thereof as a rotation center,
The method for grinding a glass substrate according to claim 1, wherein the grinding tool is rotated around the disk-shaped glass substrate against the rotation direction of the disk-shaped glass substrate.   The glass substrate grinding method according to claim 1 or 2, wherein a tool having a smaller diameter than the grinding tool is used as the second grinding tool. The glass substrate grinding method according to any one of claims 1 to 3, wherein a tool having a diameter of 2 mm or less is used as the second grinding tool. When chamfering the outer peripheral end part with grinding of the outer peripheral end part, and chamfering the notch when forming the notch ,
As the second grinding tool, the shape and size of the grinding groove formed on the outer peripheral portion of the second grinding tool for grinding are the shape and size of the grinding groove formed on the outer peripheral portion of the grinding tool. The same tool is used, The grinding method of the glass substrate in any one of Claims 1-4 characterized by the above-mentioned. The said grinding tool and said 2nd grinding tool share the rotating shaft, The grinding method of the glass substrate in any one of Claims 1-5 characterized by the above-mentioned. After forming the notches, grinding method for a glass substrate according to any one of claims 1 to 6, characterized in that etching is performed on the outer peripheral edge.

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