JP2014037035A - Grinding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily flatten a plate-like workpiece by removing undulations even when new undulations are formed when a resin is pressed against the plate-like workpiece.SOLUTION: A grinding method includes: a sticking step of allowing a holding table 10a to suck and hold a first surface 2 of a plate-like workpiece 1, and sticking an adhesive tape 5 including a substrate 6 and a paste layer 7 on a second surface 3 of the plate-like workpiece 1; a flattening step of, after the sticking step, clamping and holding side parts 4 of the plate-like workpiece 1, and cutting and flattening an upper surface 6a of the substrate 6 with a cutting tool edge 9; a first grinding step of, after the flattening step, allowing a holding table 10b to suck and hold a lower surface 6b of the substrate 6, and grinding the first surface 2 of the plate-like workpiece 1 with grinding stones 23; a peeling step of, after the first grinding step, peeling the adhesive tape 5 from the plate-like workpiece 1; and a second grinding step of, after the peeling step, allowing the holding table 10b to suck and hold the first surface 2 of the plate-like workpiece 1, and grinding the second surface 3 of the plate-like workpiece 1 with the grinding stones 23. The plate-like workpiece 1 having undulations can be easily flattened by using the grinding method.

Description

  The present invention relates to a grinding method for flattening a plate-like workpiece on which waviness is formed.

  In wafer making, for example, a cylindrical ingot such as silicon is sliced with a wire saw to form a circular plate-shaped workpiece. In this slicing, waviness may be formed in the plate-like workpiece. Therefore, in order to remove this undulation and flatten the plate-like workpiece, a resin is applied to one side of the plate-like workpiece on which the undulation is formed, and the resin is cured by heating or ultraviolet irradiation, and this resin is applied. After grinding the surface on the opposite side of the one side, the resin is peeled off from the one side and the one side is ground (see, for example, Patent Document 1 and Patent Document 2 below).

  Patent Document 3 below discloses a cutting wheel that scrapes off a resin applied to a plate-like workpiece. This cutting wheel includes a ring-shaped base and a cutting blade disposed at least at one location on the base, and can remove the resin while rotating the cutting blade.

JP 2009-148866 A JP 2011-103379 A Japanese Patent Application Laid-Open No. 2000-173954

  In order to uniformly coat the resin on the plate-like workpiece on which the undulations are formed, it is necessary to slightly press the resin against the plate-like workpiece. At this time, the swell of the plate-like workpiece is changed and the resin is cured. Sometimes. Therefore, if the surface of the plate-shaped workpiece on which the resin is not coated is ground, and then the resin is peeled off from the wavy surface of the plate-shaped workpiece, the resin is pressed by the pressing force applied to the plate-shaped workpiece when the resin is pressed. There is a problem that it is not easy to flatten the plate-shaped workpiece because a new undulation different from the undulation formed before coating the plate-shaped workpiece may be formed on the plate-shaped workpiece.

  The present invention has been made in view of the above circumstances, and even if a new swell is formed when a resin is pressed against a plate-like workpiece, the swell can be removed and the plate-like workpiece can be easily flattened. Therefore, the present invention has a problem to be solved.

  The present invention is a grinding method for flattening a plate-like workpiece with waviness by grinding, wherein a holding table sucks and holds the first surface of the plate-like workpiece and becomes a second surface opposite to the first surface. A sticking step of sticking an adhesive tape having a base material and a glue layer on the surface, and after the sticking step, the side of the plate-like workpiece is clamped and held with the adhesive tape facing up, the base A flattening step of flattening the upper surface of the base material by cutting the upper surface of the material with a cutting tool blade, and a holding table after the flattening step, with the flattened base material facing down Is held by suction, and a first grinding step of grinding the upper surface of the first surface of the plate-like workpiece with a grinding wheel, and after the first grinding step, the adhesive tape is peeled from the plate-like workpiece. After the peeling step, and after the peeling step, the first surface with the first surface ground in the first grinding step of the plate-shaped workpiece facing down. Holding table is sucked and held, it is ground and a second grinding step of grinding the surface of the second plate-like workpiece with the grinding wheel, the plate-shaped workpiece by the grinding method comprising a.

  The present invention attaches an adhesive tape along the waviness of the plate-like workpiece in the attaching step, and after cutting the waviness of the substrate constituting the adhesive tape in the flattening step with a cutting bite blade to make the substrate flat. Since the substrate is held by the holding table, the waviness formed on the first surface of the plate-like workpiece in the first grinding step can be removed. Furthermore, after the first grinding step is performed, the adhesive tape is peeled off from the plate-like workpiece in the peeling step, and the undulation formed on the second surface of the plate-like workpiece in the second grinding step can be removed. it can. Therefore, it is possible to easily flatten the plate-shaped workpiece by removing the undulations of the first surface and the second surface of the plate-shaped workpiece.

It is sectional drawing which shows the sticking process which sticks an adhesive tape to a plate-shaped workpiece. It is sectional drawing which shows the planarization process which clamps the side part of a plate-shaped workpiece | work with a clamp part, removes the wave | undulation of a base material with a cutting blade, and makes it flat. It is sectional drawing which shows the 1st grinding process of grinding the 1st surface of a plate-shaped workpiece. It is sectional drawing which shows the peeling process which peels an adhesive tape from a plate-shaped workpiece. It is sectional drawing which shows the 2nd grinding process which grinds the 2nd surface of a plate-shaped workpiece. It is sectional drawing which shows the state which clamps the side part of a plate-shaped workpiece | work with the clamp part which has a convex part by a half ring shape. It is a perspective view which shows the state which clamps the side part of a plate-shaped workpiece | work with the clamp part which has a convex part by a half ring shape.

The lower surface of the plate-like workpiece 1 shown in FIG. 1 is a first surface 2, and the upper surface on the opposite side of the first surface 2 is a second surface 3. Below, the grinding method of the plate-shaped workpiece | work 1 in which the wave | undulation was formed is demonstrated.
(1) Adhering Step First, as shown in FIG. 1, a rotatable holding table 10 a holds the plate-like workpiece 1. A porous member 12 is formed on the holding table 10a, and the surface thereof serves as a holding surface 11. The holding surface 11 is connected to an air suction source 14 through a suction hole 13.

  When the suction source 14 is activated, the holding surface 11 sucks and holds the first surface 2 of the plate-like workpiece 1 and exposes the second surface 3 of the plate-like workpiece 1 facing upward. Thereafter, the adhesive layer 7 side of the pressure-sensitive adhesive tape 5 formed by the base material 6 and the adhesive layer 7 is attached to the second surface 3 of the plate-like workpiece 1.

  As the substrate 6, for example, a dicing tape that protects the surface of the device when the plate-like workpiece is divided can be used. It is desirable that the base material 6 to be used has a thickness of approximately 100 μm to 150 μm. Note that the plate-like workpiece 1 shown in FIG. 1 has no undulation, but this is because the holding table 10 a is sucked and held, and the glue layer 7 is uniformly bonded to the second surface 3 of the plate-like workpiece 1. Thus, the adhesive tape 5 is stuck along the undulation of the plate-like workpiece 1.

(2) Planarization process After implementing the sticking process, the base material 6 of the adhesive tape 5 is planarized. When the plate-like workpiece 1 is separated from the holding table 10a shown in FIG. 1, the adhesive tape 5 is stuck along the undulation of the plate-like workpiece 1 as shown in FIG. That is, the waviness is formed on the glue layer 3 along the waviness of the second surface 3 of the plate-like workpiece 1, and the waviness is formed on the upper surface 6 a and the lower surface 6 b of the substrate 6.

  Next, as shown in FIG. 2B, the side portion 4 of the plate-like workpiece 1 is clamped and held by using, for example, a ring-shaped clamp portion 8 with the upper surface 6a of the base material 6 facing upward. The clamp portion 8 can be fixed so that the plate-like workpiece 1 does not move.

  Next, the cutting tool blade 9 shown in FIG. 2C scans the upper surface 6a of the substrate 6, and the cutting blade portion 9a provided on the cutting tool blade 9 removes the undulation of the upper surface 6a. When all the undulations are removed, the upper surface 6a of the substrate 6 is formed flat as shown in FIG.

(3) 1st grinding process After implementing a planarization process, as shown in FIG. 3, the 1st surface 2 of the plate-shaped workpiece 1 is ground. First, the plate-like workpiece 1 to which the adhesive tape 5 is attached is reversed, and the upper surface 6a of the substrate 6 is turned down so that the upper surface 6a of the substrate 6 is sucked and held on the holding surface 11 of the holding table 10b. The surface 2 is exposed upward. Next, the holding table 10b rotates in the direction of arrow A, for example. The holding table 10b has the same configuration as the holding table 10a.

  Next, the grinding means 20 for grinding the plate-like workpiece 1 operates to grind the plate-like workpiece 1. The grinding means 20 shown in FIG. 3 includes a rotatable spindle 21, a grinding wheel 22 attached to the lower end of the spindle 21, and a grinding wheel 23 that is annularly fixed to the lower portion of the grinding wheel 22. The grinding means 20 lowers the grinding wheel 23 at a predetermined grinding feed speed until it contacts the first surface 2 of the plate-like workpiece 1 while rotating the grinding wheel 22 in the direction of arrow A, for example.

  As shown in FIG. 3, when the grinding wheel 23 comes into contact with the first surface 2, the grinding means 20 applies a predetermined grinding load to the first surface 2 of the plate-like workpiece 1 by the grinding wheel 23. The waviness formed on the surface 2 is removed. In this way, the first surface 2 of the plate-like workpiece 1 is formed flat.

(4) Peeling Step After performing the first grinding step, the adhesive tape 5 is peeled from the plate-like workpiece 1 as shown in FIG. Thereby, the waviness formed on the second surface 3 of the plate-like workpiece 1 is exposed. In addition, the method of peeling the adhesive tape 5 is not specifically limited, For example, it is possible to peel the adhesive tape 5 from the plate-shaped workpiece 1 using the tape for peeling.

(5) 2nd grinding process After implementing a peeling process, as shown in FIG. 5, the 2nd surface 3 of the plate-shaped workpiece 1 is ground. First, as shown in FIG. 5A, the plate-like workpiece 1 is reversed, and the second surface 3 is formed by sucking and holding the flatly formed first surface 2 to the holding surface 11 of the holding table 10b. Expose upwards. Next, the holding table 10b rotates in the direction of arrow A, for example.

  Next, the grinding means 20 is actuated, and the grinding wheel 23 is lowered at a predetermined grinding feed rate until it contacts the second surface 3 of the plate-like workpiece 1 while rotating the grinding wheel 22 in the direction of arrow A, for example.

  As shown in FIG. 5A, when the grinding wheel 23 comes into contact with the second surface 3, the grinding means 20 applies a predetermined grinding load to the second surface 3 of the plate-like workpiece 1 by the grinding wheel 23. The waviness formed on the second surface 3 is removed. In this way, as shown in FIG. 5B, the plate-like workpiece 1 is flattened by removing the undulations of the first surface 2 and the second surface 3 of the plate-like workpiece 1.

  In the planarization step shown in the above embodiment, the device for clamping the side portion 4 of the plate-like workpiece 1 is not limited to the clamp portion 8. For example, as shown in FIG. 6, it is possible to use the clamp part 30 which provided the convex part toward the inner peripheral side so that the plate-shaped workpiece 1 can be supported from the lower side. As shown in FIG. 7, the at least two clamp portions 30 can be divided into two starting from the groove 31, and each is formed in a semi-ring shape. And it can clamp so that the plate-shaped workpiece | work 1 may be surrounded by the two clamp parts 30. FIG.

  As described above, the adhesive tape 5 is attached along the undulation of the plate-like workpiece 1 in the attaching step, and the undulation of the base material 6 constituting the adhesive tape 5 is cut with the cutting tool blade 9 in the flattening step. After the substrate 6 is flattened and the holding table 10b holds the substrate 6, the waviness formed on the first surface 2 of the plate-like workpiece 1 in the first grinding step is removed, and in the second grinding step Since the waviness formed on the second surface 3 of the plate-like workpiece 1 can be removed, the plate-like workpiece 1 can be easily flattened.

1: Plate workpiece 2: First surface 3: Second surface 4: Side portion 5: Adhesive tape 6: Base material 6a: Upper surface 6b: Lower surface 7: Adhesive layer 8: Clamping portion 9: Cutting tool blade 9a: Cutting blades 10a, 10b: holding table 11: holding surface 12: porous member 13: suction hole 14: suction source 20: grinding means 21: spindle 22: grinding wheel 23: grinding wheel 30: clamp part 31: groove

Claims (1)

A grinding method for flattening a plate-like workpiece with waviness by grinding,
An adhering step in which a holding table sucks and holds the first surface of the plate-like workpiece, and an adhesive tape including a base material and a glue layer is attached to a second surface that is the opposite surface of the first surface;
After the adhering step, the side of the plate-like workpiece is clamped and held with the adhesive tape facing up, and the upper surface of the substrate is cut with a cutting tool blade to flatten the upper surface of the substrate. A planarization process;
After the flattening step, a holding table sucks and holds the lower surface of the base material with the flattened base material down, and the upper surface of the first surface of the plate workpiece is ground with a grinding wheel. 1 grinding process;
After the first grinding step, a peeling step for peeling the pressure-sensitive adhesive tape from the plate-like workpiece;
After the peeling step, a holding table sucks and holds the first surface with the first surface ground in the first grinding step of the plate-like workpiece, and the plate-like workpiece is A second grinding step of grinding the surface of 2 with a grinding wheel.

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