JP5877520B2 - Planarization processing apparatus and planarization processing method for sapphire substrate - Google Patents

Description

  The present invention relates to an apparatus for flattening a surface of a sapphire substrate having a thickness of 400 to 525 μm obtained by wire-cutting a sapphire ingot and a flattening method. As the sapphire substrate to be flattened, there is also an object of a flattening method that reduces the thickness of 400 to 525 μm of the sapphire substrate on the back surface of the optical device substrate in which the optical device layer is formed on the surface of the sapphire substrate to 5 to 30 μm. included.

The sapphire substrate used for the LED is prepared through the following steps S01 to S09 as disclosed in Japanese Patent Application Laid-Open No. 2007-137736 (Patent Document 1).
(S01) Pull up the crystal rod of the sapphire ingot.
(S02) The surface of the ingot is annealed.
(S03) The crystal orientation of the ingot is cut so that the C-axis end face is a vertical plane to form an ingot block.
(S04) The outer peripheral surface of the ingot block is cylindrically ground to obtain a cylindrical block having a smooth surface.
(S05) The crystal orientation of the cylindrical block is measured with an X-ray orientation measuring device (XRD machine), and an orientation flat is formed on the ingot block with a grindstone.
(S06) The ingot block on which the orientation flat is formed is wire-cut into a plane perpendicular to the C axis to obtain a large number of 400 to 525 μm thick sapphire substrates.
(S07) The surface of the sapphire substrate is ground or lapped to flatten the surface. The sapphire substrate whose surface is flattened is etched or annealed.
(S08) The treated sapphire substrate is polished on one side (polished) to flatten the surface.
and,
(S09) The polished sapphire substrate is washed.

JP 2010-514581 A (Patent Document 2) holds a sapphire substrate obtained by wire cutting on a suction chuck and rough-grinds the surface of a sapphire substrate using a rough grinding wheel to increase the surface thickness to 30 μm or more. After removal, the surface of the sapphire substrate is removed by 5 μm or more using a finish grinding wheel to obtain a sapphire substrate having a surface roughness Ra of 0.1 μm or less, and further, the finish grinding surface is subjected to CMP polishing using a polishing pad. A surface having a crystal orientation selected from the group consisting of an r-plane, an m-plane, and a c-plane orientation and having an nTTV of about 0.037 μm / cm ² or less and a roughness Ra of 10.0 mm or less. A method for manufacturing a sapphire substrate is proposed.

  Japanese Unexamined Patent Application Publication No. 2010-46744 (Patent Document 3) is a grinding method for grinding the back surface of a sapphire wafer in which a plurality of optical devices are stacked on a sapphire substrate and divided by lines to be divided. A stress distribution step of cutting the whole or part of the dividing line of the semiconductor layer to disperse the stress, a protective tape attaching step of attaching a protective adhesive easy-release tape to the surface of the semiconductor layer, and the protective tape side A sapphire wafer grinding method is provided, comprising a step of holding a sapphire wafer on a chuck table of a grinding apparatus and grinding a back surface of the sapphire wafer with a grinding wheel.

JP 2011-44473 A (Patent Document 4) discloses a chuck table that can be rotated while holding a sapphire substrate with a protective adhesive easy-release tape affixed to the optical device layer side with the sapphire substrate surface facing upward, A sapphire substrate back surface grinding device comprising a grinding means for rotatably supporting a grinding wheel having a grinding wheel for grinding a sapphire substrate surface held by the chuck table, the chuck table sucking the sapphire substrate A suction plate having a holding surface for holding; and a frame body having a bottom portion that surrounds other than the holding surface of the suction plate and supports the opposite surface of the holding surface; The suction groove is formed so as to be denser in the central portion compared to the outer peripheral portion so that the suction force in the central portion is stronger than the suction force in the outer peripheral portion. Suction plate, characterized in that it communicates with the suction source through a suction groove formed in the frame body, proposes a backside grinding apparatus of the sapphire substrate.

  On the other hand, a lapping machine “SPL15F” (trade name) with a facing device is on the market a lot as described in the semiconductor device catalog (Non-patent Document 1) of the present applicant.

Okamoto Machine Tool Manufacturing Co., Ltd. Semiconductor Related Equipment Catalog, “Precision Wrapping Machine SPL15F”, published in June 2010

JP 2007-137736 A Japanese translation of PCT publication 2010-51481 JP 2010-46744 A JP 2011-44473 A

  Unlike single crystal silicon, which is the material of the silicon substrate, the sapphire substrate is a hexagonal crystal. Therefore, when grinding with a grindstone, the sapphire substrate that has been ground by the frictional heat that the substrate and the grindstone rub against each other tends to warp. is there. Therefore, it is preferable to adopt the two-stage grinding process of the rough grinding process and the finish grinding process described in Patent Document 2 because the warpage of the sapphire substrate obtained by grinding is smaller than the one-stage grinding method of Patent Document 1. .

  The sapphire substrate in which the protective adhesive easy-release tape of Patent Document 3 and Patent Document 4 is attached to the surface of the optical device layer is preferable for further reducing the degree of warpage of the ground sapphire substrate.

  When the backside grinding method of the sapphire substrate with the protective adhesive easy-release tape affixed to the surface of the optical device layer of Patent Literature 3 and Patent Literature 4 is ground so that warpage does not become a problem in the subsequent polishing step, a grinding wheel It is difficult to increase the rotation speed of the sapphire, and there is a drawback that the back grinding time of the sapphire substrate becomes long. Further, even in the subsequent polishing step, there is a drawback that warpage of the sapphire substrate polished by frictional heat when the substrate to be polished is rubbed against a cushioning (elastic) polishing pad is increased. The warp caused by this polishing friction can be solved to some extent by annealing the sapphire substrate.

  With the increase in demand for LED consumption, the emergence of a high productivity sapphire substrate planarization apparatus is desired in the optical device market. Since the grinding time is a rate-determining process in the flattening process of the sapphire substrate, the inventors of the present application can divide the grinding process into three stages: rough grinding process, intermediate finish grinding process, and finish grinding process. In the process, the influence of the thermal history on the sapphire substrate is reduced, and the occurrence of warpage is suppressed with the effect of the protective adhesive easy-release tape. Further, it has been conceived that the occurrence of warpage can be suppressed by adopting a lapping process using a hard metal lapping plate instead of the polishing process.

  Then, by taking the three-stage grinding process, it was conceived that the lapping process was designed to simultaneously lapping two sapphire substrates, thereby providing a highly productive sapphire substrate planarization apparatus.

According to the first aspect of the present invention, the room in which the flattening apparatus is installed is directed from the front part toward the rear part, the front left half part of the room is used as a workpiece transfer chamber / work washing room, and the front right half part is used as a workpiece lapping chamber. The rear part is divided into three sections with the workpiece grinding chamber,
The workpiece transfer chamber / work washing chamber has a plurality of workpiece storage cassettes in the front row from the front to the rear,
In the second row, an articulated arm type work transfer robot in the center,
In the third row, from left to right,
In the first row on the left side, a workpiece suction transporter that can slide the second guide rail on the upper wall of the club room,
A temporary mounting table in front of the second row, a roll rotary work surface washer in the rear of the second row,
An arm washer for an articulated arm type work transfer robot behind the articulated type work transfer robot in the third row,
In the 4th row, there is a spin cleaner on the back side of the lapping workpiece and a Bergrin cleaner for the lapping workpiece surface.
In the fourth row, from left to right,
Provided on the right side of the workpiece adsorption transporter and behind the roll rotary workpiece surface cleaner is a ground workpiece spinner cleaner,
A temporary table with a centering device is provided on the right side of the spinner cleaner for the ground workpiece and behind the arm cleaner for the articulated arm-type workpiece transfer robot,
A work entrance window is provided on the left side wall of the four walls surrounding the lapping chamber in the right front half portion, and a lapping head for a metal rotating surface plate is provided in the lapping chamber. A pair of work pressing means provided so as to be able to swing on the lifting and rotating shafts, a pair of work suction head cleaning devices provided with a rotating brush for cleaning the lower part of the workpiece suction head, and two metal rotating surface plate rings It is equipped with a conditioner, a metal rotating surface plate washing mechanism, and a metal rotating surface plate facing device.
In the rear grinding chamber,
One index table, and a driving means for rotationally driving the rotation shaft of the index table;
Four suction chuck tables provided in four cylindrical punching spaces installed at equal intervals on the same circumference centered on the rotation axis of the index table, and the rotation shafts of the four suction chuck tables are rotated. Driving means for driving,
Of the four suction chuck tables, the first suction chuck table located near the temporary work table with the grinding work washer and centering device in the work transfer chamber / work washing chamber is positioned at the loading / unloading stage (s ₁ ). The L-shaped side wall and the ceiling of the left half of the wall surrounding the loading / unloading stage (s ₁ ) position are deleted, and an up and down arm is provided on the top of the wall. A first work transfer mechanism having a first guide rail capable of moving between a center point and the center point of the temporary table with the centering device is provided, and loading / unloading is performed by the first suction chuck table and the first work transfer mechanism. Configure stage (s ₁ )
Above the second suction chuck table, a rough grinding head in which a cup wheel type rough grinding wheel is supported on the grinding wheel shaft is provided, and the second suction chuck table and the rough grinding head constitute a rough grinding stage (s ₂ ).
The third suction chuck Above the table provided finish grinding head in which the finish grinding wheel in a cup-wheel is journalled in the wheel spindle third suction chuck table and semi-finish grinding head and a medium finish grinding stage (s ₃₎ Configure
and,
Above the fourth suction chuck table, a finish grinding head having a cup wheel type finish grinding wheel supported by a grinding wheel shaft is provided, and the fourth suction chuck table and the finish grinding head constitute a finish grinding stage (s ₄ ). Set up a stage,
Next to the first suction chuck table constituting the loading / unloading stage (s ₁ ), there is provided a pendant swing rotation type work suction transport pad mechanism in which a suction pad is supported by an arm. Installed to swing and rotate between a single chuck table and the spin cleaner of the ground workpiece,
The arm of the articulated arm type workpiece transfer robot in the workpiece transfer chamber / work washing chamber described above includes a storage cassette, a temporary table with a centering device, a grinding workpiece cleaning device, a temporary table, and a lapping workpiece surface cleaning device It is possible to move a trajectory that can transport the workpiece adsorbed to the upper workpiece and the lower part of the pair of workpiece adsorbing heads, and to move a trajectory that can transport the workpiece to these devices,
The workpiece suction and transfer device that can slide on the second guide rail in the workpiece transfer chamber and workpiece cleaning chamber is on the line connecting the center point of the temporary table, the roll rotary workpiece surface cleaner, and the center point of the spinner cleaner. Designed to move,
An apparatus for planarizing a sapphire substrate is provided.

According to a second aspect of the present invention, the flattening apparatus according to the first aspect is used to flatten the surface of the sapphire substrate through the following steps to reduce the thickness of the sapphire substrate. The present invention provides a chemical processing method.
1) Transfer the sapphire substrate (workpiece) with the easily peelable adhesive tape in the storage cassette on the surface onto a temporary table with a centering device using an articulated arm-type workpiece transfer robot. Place the workpiece on.
2). The workpiece on the temporary table with the centering device is transferred onto the first suction chuck table by using the workpiece first transport mechanism so that the easily peelable adhesive tape surface of the workpiece is the lower surface and the sapphire substrate surface is the upper surface. The workpiece is placed on the first suction chuck table.
3). The index table is rotated 90 degrees to move the first chuck table on which the workpiece at the loading / unloading stage (s ₁ ) position is mounted to the second chuck table position at the rough grinding stage (s ₂ ) position.
4). Rotate the second chuck table, then rotate and lower the rough grinding head to bring the cup wheel type rough grinding wheel into contact with the sapphire substrate surface of the workpiece and rub it to start the rough grinding process. Rough grinding is performed by lowering the rough grinding wheel and performing in-feed grinding of the sapphire substrate surface.
5). The index table is rotated 90 degrees to move the second chuck table at the rough grinding stage (s ₂ ) position to the third chuck table position at the intermediate finish grinding stage (s ₃ ) position.
6). Rotate the third chuck table, then rotate and lower the semi-finishing grinding head to bring the cup wheel type semi-finishing grinding wheel into contact with the sapphire substrate surface of the workpiece and rub it to start the semi-finishing grinding process. The cup wheel type intermediate finishing grinding wheel is lowered to perform intermediate finishing grinding for in-feed grinding of the sapphire substrate surface.
7). The index table is rotated 90 degrees clockwise to move the third chuck table at the intermediate finish grinding stage (s ₃ ) position to the fourth chuck table position at the finish grinding stage (s ₄ ) position.
8). Rotate the fourth chuck table, then rotate and lower the finish grinding head to bring the cup wheel type finish grinding wheel into contact with the sapphire substrate surface of the workpiece and rub it to start the finish grinding process. Finish grinding is performed by lowering the finish grinding wheel and performing in-feed grinding of the sapphire substrate surface.
9). The index table is rotated 90 degrees clockwise or 270 degrees counterclockwise, and the fourth chuck table at the finish grinding stage (s ₄ ) position is positioned at the loading / unloading stage (s ₁ ) position. Move to the chuck table position.
10). After moving the ground workpiece mounted on the first chuck table at the loading / unloading stage (s ₁ ) position onto the workpiece spinner cleaner using the workpiece suction transfer pad mechanism, the workpiece is Place on the work spinner cleaner.
11). The workpiece is spin cleaned while spraying cleaning water onto the workpiece surface ground by the workpiece spinner cleaner.
12). The workpiece suction / conveying device is moved back on the second guide rail and moved onto the spinner cleaner of the workpiece, and the ground and cleaned surface of the workpiece placed on the spinner cleaner is sucked.
13). The work suction / conveyance device is moved back on the second guide rail and passed over the roll rotary work surface cleaning device, and the tape surface on the back surface of the work is roll cleaned.
14). The workpiece suction transporter is further retracted on the second guide rail and stopped on the temporary table, and the workpiece is placed on the temporary table with the tape surface of the workpiece facing down and the grinding / cleaning sapphire substrate surface facing up. Put.
15). Using the articulated arm type work transfer robot, the grinding / cleaning sapphire substrate surface is transferred to a position below the work suction head in the lapping chamber, and the work sticking surface of the work suction head is directed upward. Deliver the work downward.
16). The work arm is rotated onto the metal rotating surface plate by rotating the revolving arm of the work suction head.
17). The workpiece newly placed on the temporary table with the grinding / cleaning sapphire substrate surface facing upward is below the vacant workpiece suction head in the lapping chamber using the articulated arm-type workpiece transfer robot. The workpiece is transferred to a position, and the workpiece is delivered below the workpiece suction head with the tape application surface of the workpiece facing upward.
18). The revolving arm of the work suction head is rotated to position the work on the metal rotating surface plate.
19). A pair of the workpiece suction heads are lowered to bring the sapphire substrate surface of the workpiece into contact with the metal rotating surface plate and rubbed to start lapping of the two workpieces, and a desired lapping allowance amount is obtained. When lapping is performed, the rotation of the metal rotating surface plate is stopped and the pair of the workpiece suction heads are raised, and then the swing arm of the workpiece suction head is rotated in the opposite direction to the workpiece suction head standby position. Return to ending lapping.
20). Move the arm of the articulated arm-type workpiece transfer robot below the workpiece suction head, and then suck the workpiece lapping sapphire substrate sucked below the workpiece suction head with the arm and then suck the workpiece Release the pressure reduction of the head, and then move the arm of the articulated arm type work transfer robot onto the spin cleaner on the back surface of the lapping workpiece, where the pressure reduction of the arm is released and the lapping surface of the workpiece is moved. Place it on the spinner temporary table.
21). The spin cleaning of the workpiece is performed while spraying cleaning water on the front and back surfaces of the workpiece using the spin cleaner and the Berglin cleaner, and the cleaning water adhering to the workpiece is wiped off with Berglin.
22). Using the articulated arm-type workpiece transfer robot, the workpiece on the spin cleaner on the back of the lapping workpiece is gripped or sucked, and then the workpiece is stored in a storage cassette.
23). The arm of the articulated arm type work transfer robot is transferred onto the arm cleaner for the articulated arm type work transfer robot, and the arm is cleaned.
24). Move the arm of the articulated arm-type workpiece transfer robot whose arm has been cleaned to the lower side of the other workpiece suction head, and then wrap the sapphire substrate surface of the workpiece sucked under the workpiece suction head. Then, the arm of the articulated arm type work transfer robot is moved onto the spin cleaner on the back surface of the lapping workpiece, and is placed on the spinner temporary table with the lapping surface of the workpiece facing up.
25). The spin cleaning of the workpiece is performed while spraying the cleaning water on the front and back surfaces of the workpiece using the spin cleaner and the Berglin cleaner, and the cleaning water adhering to the workpiece is wiped off.
26). The arm of the articulated arm type work transfer robot is moved onto a spin cleaner on the back surface of the lapping work, and after gripping or adsorbing the work, the arm of the articulated type arm type work transfer robot is moved to a shelf of a storage cassette. The workpiece is transferred into the storage cassette and stored in the storage cassette.
27). The arm of the articulated arm type work transfer robot is transferred onto the arm cleaner for the articulated arm type work transfer robot, and the arm is cleaned.
28). While the steps 20) to 27) are being performed, the metal rotating surface plate is rotated in the lapping chamber, and the cleaning water is supplied from the metal rotating surface plate washer to the metal rotating surface plate. In addition, the lower part of the workpiece suction head is cleaned by the workpiece suction head cleaner.

  In order to prevent the effect of warping of the workpiece due to the thermal history accumulated in the workpiece in the grinding process stage, the grinding stage is divided into three stages to reduce the initial extinction at each grinding stage and make it easy to peel. The occurrence of warpage is further reduced by backing the workpiece with an adhesive tape.

  Since there is a cleaning process for the surface of the workpiece that is easily contaminated by the processing waste generated in each workpiece conveyance process, grinding process, and lapping process, and an arm cleaning process for the articulated transfer robot, it adheres to the workpiece. The number of foreign particles is extremely small.

  Since rough grinding of workpieces in the grinding machine is the rate-limiting process, the grinding wheel axis is designed to be 3 axes and the lap workpiece suction head is designed to be 2 axes. Lapping can be performed, and the production volume per unit time of the workpiece can be improved.

FIG. 1 is a plan view of a flattening apparatus for a sapphire substrate. FIG. 2 is a right side view of the work suction / conveyor capable of sliding on the first guide rail. FIG. 3 is a right side view of the articulated arm type work transfer robot and the temporary table. FIG. 4 is a right side view of the articulated arm type work transfer robot and the lapping machine. FIG. 5 is a right side view in which a part of the lapping machine in the lapping chamber is cut away. FIG. 6 is a rear view of the lapping machine with a part cut away when viewed from behind. FIG. 7 is a front view in which a part of the grinding apparatus is cut away.

Hereinafter, the present invention will be described in more detail with reference to the drawings.
The sapphire substrate flattening apparatus 1 shown in FIG. 1 has a room 2 in which the flattening apparatus is installed facing from the front part to the rear part, the front left half of the room 2 is the work transfer chamber / work washing room 2a, and the front part. The right half is divided into a lapping chamber 2c for workpieces, and the rear portion is divided into three sections with a workpiece grinding chamber 2b.

  By making the grinding chamber 2b with a large amount of generated grinding scraps backward and bringing the lapping chamber of the final process forward, the chance of processing scraps adhering to the final workpiece is reduced.

From the front to the rear, the workpiece transfer chamber / work washing chamber 2a has a plurality of workpiece storage cassettes 3 and 3 in the front row, and an articulated arm type workpiece transfer in the center in the second row. From the left side to the right side in the third row, the robot 4 is provided with a workpiece suction transfer device 7 having a suction pad 7a that can slide on the second guide rail 7b on the upper wall of the chamber in the first left side column, A temporary table 9 in front of the second row, a roll rotary work surface cleaner 8 in the rear of the second row, and an articulated arm type behind the articulated workpiece transfer robot 4 in the third row. The arm cleaning device 10 for the suction arm 4a of the workpiece transfer robot is provided with a spin cleaning device 11a on the back surface of the lapping workpiece and a berlin cleaning device 11b for the spin cleaning device in the fourth row. The workpiece is attracted from the right side A spinner cleaner 6 for a ground workpiece is provided on the right side of the feeder 7 and behind the roll-rotating workpiece surface cleaner 8, and the spinner cleaner 6 for the ground workpiece is provided. And a temporary table 5 with a centering device is provided behind the arm washer 10 for the articulated arm type work transfer robot. The storage cassettes 3 and 3 are installed on the tilt mechanism base 3a in order to easily carry out and carry in the work by the arm 4a of the articulated arm type work transfer robot 4.

  The workpiece can be gripped by the arm 4a of the articulated arm-type workpiece transfer robot 4 by vacuum suction by the arm 4a having a vacuum hole in the lower surface of the arm, or the workpiece outer periphery can be gripped by both arm claws provided at the tip of the arm 4a. This type of multi-joint arm-type workpiece transfer robot can also be used.

  The spin cleaner 11a rotates the workpiece with a spinner while spraying line clean water from the nozzle to the lower surface and upper surface of the workpiece to clean the front and back of the workpiece, and the Berglin cleaner 11b advances a cleaning brush on the workpiece upper surface to move the workpiece upper surface. Clean the scrub.

The left side wall of the fourth wall surrounding the lapping chamber 2c of the front right half portion, the workpiece carry-in port window 2c _l is provided, this lapping chamber, work for one of the metal rotation plate 21 A pair 24, 24 of work pressing means provided with the suction head 22 so that it can be moved up and down and rotated on the rotary shaft 23, and a pair 25, 25 of a work suction head washer comprising a rotating brush 25a for cleaning the lower part of the work suction head. And a lapping machine 20 having two metal rotating surface plate ring conditioners 26, 26, a metal rotating surface plate cleaning mechanism 27, and a single metal rotating surface plate facing device 28. ing.

  As the metal of the metal rotating surface plate 21 material, there can be used a casting surface plate made of copper, tin, brass, iron or the like, or a mixed casting of these metal powder and resin, for example, a chemet surface plate.

  In the rear grinding chamber 2b, there is one index table 31, driving means 33 for rotationally driving the rotary shaft 32 of the index table, and on the same circumference with the rotational axis of the index table as the center point. Provided with four suction chuck tables 34a, 34b, 34c, 34d provided in four hollow cylindrical spaces installed at equal intervals, and driving means 36 for rotationally driving the rotation shafts 35 of the four suction chuck tables. To do.

Of the four suction chuck tables 34a, 34b, 34c, 34d, the first suction chuck table is located close to the grinding workpiece cleaner 6 and the temporary table 5 with a centering device in the workpiece transfer chamber / work cleaning chamber 2a. 34 a is a loading / unloading stage (s ₁ ) position, and the L-shaped side wall and ceiling of the left half 2 b _l of the wall surrounding the loading / unloading stage (s ₁ ) position are deleted, and the top of the wall Includes a claw that can move back and forth to hold a work that can be moved up and down, or a transport pad mechanism 39 having an arm 39a that includes a suction pad. A second guide rail 39b that moves between the transport pad mechanism 39 and the first suction Make up the the loading / unloading Rohde queuing stage _{(s 1)} in the Yakkuteburu 34a.

Rough grinding with a second suction chuck table 34b second suction chuck table 34b and the rough grinding head 34h _c provided rough grinding head 34h _c with a cup wheel type rough grinding 34g _c is journalled in the wheel spindle 34o above the The stage (s ₂ ) is configured.

As the cup wheel type rough grinding wheel 34g _c , a rough grinding wheel using diamond grains having a grinding number of # 180 to # 380 and CBN grains as a cutting edge material is used. The grindstone shaft 34o is rotationally driven by a built-in motor 34m.

Third and third suction chuck table 34c and the semi-finish grinding head 34h _m finish grinding wheel 34g _m in the cup wheel type provided finish grinding head 34h _m in which is journalled in the wheel spindle 34o above the suction chuck table 34c The intermediate finish grinding stage (s ₃ ) is constituted by

The cup wheel type in the finishing grinding wheel 34g _m, abrasive numbered diamond grains # 660 and # 420, the finishing grinding wheel in which the CBN particles and the cutting edge material is utilized.

Finish grinding with the fourth adsorption fourth suction chuck table 34d above the chuck table 34d provided finish grinding head 34h _f with a cup wheel type finishing grindstone 34g _f is journalled in the wheel spindle 34o and finish grinding head 34h _f The stage (s ₄ ) is configured.

The cup wheel type finishing grindstone 34g _f, abrasive numbered diamond grains # 800 and # 680, the finishing grinding wheel having a CBN particle and the cutting edge material is utilized.

A pendant that can swing and swing an arm 34k that supports a workpiece suction / conveying pad 34p around a rotation axis near the first suction chuck table 34a constituting the loading / unloading stage (s ₁ ) and outside the index table 31. A workpiece suction / transport pad mechanism 34t of the type is provided, and the workpiece suction / transport pad 34t is installed so as to swing and rotate between the first suction chuck table 34a and the spin cleaner 6 of the ground workpiece. To do.

  The arm of the articulated arm-type workpiece transfer robot 4 in the workpiece transfer chamber / work washing chamber 2a described above includes a storage cassette 4, a temporary table 5 with a centering device, a grinding workpiece cleaner 6, a temporary table 9, and It is possible to move the trajectory on which the workpiece on the cleaner 25 on the lapping workpiece surface and the workpiece adsorbed to the lower part of the pair of workpiece suction heads 22 and 22 can be transported, and the trajectory on which the workpiece can be transferred to these devices. Is.

  The above-described workpiece adsorption / conveyance device capable of sliding on the second guide rail in the workpiece conveyance chamber / work washing chamber 2a is the center point of the temporary table 9, the center of the roll rotary type workpiece surface cleaning device 8, and the center of the spinner cleaning device 6. It is designed to be able to move on the line connecting the points.

  The step of flattening the sapphire substrate surface of the sapphire substrate to which the easily peelable adhesive tape is attached using the sapphire substrate flattening apparatus 1 of the present invention is performed through the following steps.

A workpiece is prepared by attaching an easily peelable adhesive tape to the surface of a 6-inch diameter sapphire substrate wire-cut to a thickness of 550 μm. Easy-release adhesive tapes include Q-chuck (trade name) of Maruishi Sangyo Co., Ltd., FIXFILM (trade name) series of Fuji Copian Co., Ltd. The peel force (conforming to JIS K-6854) is 10 mN / 12.7 mm width or less, and the shear force between the sapphire substrate and the adhesive layer when the suction pad that adsorbs the workpiece is shifted laterally is 1.0 N / What is cm < ² > or more is preferable.

1) The sapphire substrate (work) w with the easily peelable adhesive tape in the storage cassette 3 attached to the surface is adsorbed to the arm 4a of the articulated arm type work transfer robot 4 and placed on the temporary table 5 with a centering device. The arm is depressurized and the work is placed on the temporary table 5 with the centering device.

  2). After lowering the arm of the work first transport mechanism 39 to suck the work on the temporary table 5 with the centering device by the suction pad 39a, the arm is lifted. Next, after the arm that sucks the workpiece is moved on the first guide rail 39b and is positioned above the center point of the first suction chuck table 34a, the suction pad 39a that sucks the workpiece is lowered and the first suction chuck table is lowered. The workpiece w is placed so that the easily peelable adhesive tape surface is on the lower surface and the sapphire substrate surface is the upper surface. Thereafter, the vacuuming of the suction pad is stopped, and the suction pad is lifted away from the workpiece surface.

3). The index table 31 is rotated 90 degrees to move the first chuck table 34a mounted with the workpiece at the loading / unloading stage (s ₁ ) position to the second chuck table 34b position at the rough grinding stage (s ₂ ) position. .

4). The second chuck table 34b is rotated at 300 rpm, and then the rough grinding head 34h _c is rotated and lowered at 3,000 rpm to bring the cup wheel type rough grinding wheel 34g _c into contact with and rub against the sapphire substrate surface of the workpiece. By starting the rough grinding process, lowering the cup wheel type rough grinding wheel 34g _c to infeed grinding the sapphire substrate surface, and raising the rough grinding head 34h _c when the rough grinding allowance of 100 μm thickness is reached. Finish the rough grinding process away from the workpiece surface. Next, the rotation of the second chuck table 34b is stopped. While this rough grinding is being performed, a new workpiece is placed on the first chuck table 34a at the loading / unloading stage (s ₁ ) position.

5). The index table 31 is rotated 90 degrees to move the second chuck table 34b at the rough grinding stage (s ₂ ) position to the third chuck table 34c position at the intermediate finish grinding stage (s ₃ ) position.

6). Third chuck table 34c is rotated at 280 rpm, then contact the rotation and descent is allowed by the cup wheel type in the finishing grinding wheel 34g _m the semi-finish grinding head 34h _m at 3,000rpm the sapphire substrate surface of the work, rubbing It is allowed to start the semi-finish grinding, the the infeed grinding of the sapphire substrate surface by further lowering the cup wheel type in the finishing grinding wheel 34g _m, the semi-finish grinding head When a finish grinding allowance in the 70μm thick The intermediate finish grinding process is finished by moving it away from the workpiece surface. Next, the rotation of the third chuck table 34c is stopped. While the intermediate finish grinding is being performed, a new workpiece is placed on the first chuck table 34a at the loading / unloading stage (s ₁ ) position, and is placed at the rough grinding stage (s ₂ ) position. On a certain second chuck table 34b, rough grinding of the workpiece is performed.

7). The index table 31 is rotated 90 degrees in the clockwise direction to move the third chuck table 34c at the intermediate finish grinding stage (s ₃ ) position to the fourth chuck table position at the finish grinding stage (s ₄ ) position.

8). The fourth chuck table 34d is rotated at 280 rpm, and then the finish grinding head 34h _f is rotated and lowered at 3,000 rpm so that the cup wheel type finish grinding wheel 34g _f comes into contact with and rubs against the sapphire substrate surface of the workpiece. start the finish grinding, by further infeed grinding the sapphire substrate surface lowers the cup wheel type finishing grindstone 34g _f, increasing the finish grinding head 34h _f If a finish grinding allowance of 50μm thickness Finish grinding by moving away from the workpiece surface. Next, the rotation of the fourth chuck table 34d is stopped. While this finish grinding is being performed, a new workpiece is placed on the first chuck table 34a at the loading / unloading stage (s ₁ ) position and is at the rough grinding stage (s ₂ ) position. The rough grinding of the workpiece is performed on the second chuck table 34b, and the semi-finished grinding of the workpiece is performed on the third chuck table 34c at the position of the intermediate finish grinding stage (s ₃ ).

9). The index table is rotated 90 degrees clockwise or 270 degrees counterclockwise to move the fourth chuck table 34d at the finish grinding stage (s ₄ ) position to the loading / unloading stage (s ₁ ) position. One chuck table 34a is moved to the position.

10). The ground workpiece surface mounted on the first chuck table 34a at the loading / unloading stage (s ₁ ) position is adsorbed by the adsorption pad 34p of the workpiece adsorption / transfer pad mechanism 34t, and then the arm of the workpiece adsorption / transfer pad mechanism 34k is turned leftward and moved to the spinner cleaner 6 for the workpiece that has been ground, and then the work suction spinner cleaner is released by releasing the pressure reduction of the workpiece suction transfer pad 34p and releasing the suction of the workpiece. 6 is mounted. Then, the arm of the work suction / transport pad mechanism 34t is rotated rightward to return the arm of the work suction / transport pad mechanism to the standby position.

  11). The workpiece is spin cleaned while spraying cleaning water onto the workpiece surface ground by the workpiece spinner cleaner 6. If this spin cleaning is started before returning the arm of the workpiece suction transfer pad mechanism 34t to the standby position, the workpiece suction transfer pad 34p can be washed with water together with the workpiece spin cleaning.

  12). The suction pad 7a of the workpiece suction / conveyor 7 is retracted on the second guide rail 7b and moved onto the spinner cleaner 6 of the workpiece, and the workpiece placed on the spinner cleaner 6 is ground and cleaned. Adsorb the surface.

  13). The suction pad 7a of the workpiece suction / conveying device 7 is retracted on the second guide rail and passed over the roll-rotating workpiece surface cleaning device 8, and the easily peelable adhesive tape surface on the back surface of the workpiece is cleaned with roll rotation water.

  14). The suction pad 7a of the workpiece suction transporter 7 is further retracted on the second guide rail 7b and stopped on the temporary placement table 9, and then the pressure reduction of the suction pad 7a of the workpiece suction transporter 7 is released to release the temporary placement table 9. The workpiece is placed with the tape surface of the workpiece facing down and the grinding / cleaning sapphire substrate surface facing upward.

  15). The grinding / cleaning sapphire substrate surface is attracted to the arm 4a of the articulated arm-type workpiece transfer robot 4, and the workpiece w is attached to the tape while the workpiece is transferred to a position below the workpiece suction head 22 in the lapping chamber 2c. After the arm 4a is turned so that the surface faces upward, the work is positioned below the work suction head 22 in the lapping chamber, and the work suction head is depressurized to suck and fix the tape application surface of the work.

  16). The revolving arm of the work adsorption head 22 is rotated about the rotation axis 23 to position the work on the metal rotating surface plate 21.

17). The workpiece w newly placed on the temporary table 9 with the grinding / cleaning sapphire substrate surface facing upward is adsorbed to the arm 4a of the articulated arm type work transfer robot 4 to adsorb the workpiece in the lapping chamber. While the workpiece is being transferred to a position below the head 22, the arm is turned so that the tape application surface of the workpiece faces upward, and then the workpiece is positioned below the empty workpiece suction head 22 in the lapping chamber. Then, the work suction head is depressurized to fix the tape application surface of the work by suction.

  18). The revolving arm of the work suction head 22 is rotated to position the work on the metal rotating surface plate 21.

  19). A pair of the workpiece suction heads 22 and 22 are lowered and the sapphire substrate surface of the workpiece is brought into contact with and slid on the metal rotating surface plate 21 rotating at a speed of 180 mm / min. Is started, and when the lapping process has a lapping amount of 20 μm, the rotation of the metal rotating surface plate 21 is stopped and the pair of workpiece suction heads 22 and 22 are raised, and then the workpiece suction is performed. The revolving arm of the head 22 is rotated in the opposite direction to the above and returned to the workpiece suction head standby position, and the lapping process is completed.

20). The arm 4a of the articulated arm-type workpiece transfer robot 4 is moved below the workpiece suction head 22, and the lap sapphire substrate surface of the workpiece sucked below the workpiece suction head 22 is moved by the arm 4a. After the suction, the pressure reduction of the workpiece suction head 22 is released, and then the arm of the articulated arm type work transfer robot 4 is moved onto the spin cleaner 11a on the back surface of the lapping workpiece, where the pressure of the arm 4a is reduced. cancel placed on the spinner provisional table 11a _t toward the lapping surface of the workpiece to above.

  21). The spin cleaning of the workpiece is performed while spraying cleaning water on the front and back surfaces of the workpiece using the spin cleaning device 11a and the Bergrin cleaning device 11b, and the cleaning water adhering to the workpiece is wiped off with Berglin.

  22). After moving the arm 4a of the articulated arm-type workpiece transfer robot 4 onto the spin cleaner 11a on the back surface of the lapping workpiece, the arm is decompressed to adsorb the lapping surface of the workpiece, and then the articulated arm type The arm of the workpiece transfer robot is transferred into the shelf of the storage cassette 3, where the pressure of the arm 4 a is released and a workpiece having a sapphire substrate thickness of 310 μm is stored in the storage cassette 3.

  23). The arm of the articulated arm type work transfer robot 4 is transferred onto the arm cleaner 10 for the articulated arm type work transfer robot, and the arm 4a is cleaned.

24). The arm 4a of the articulated arm-type workpiece transfer robot 4 with the arm cleaned is moved below the other workpiece suction head 22, and then the workpiece lapping sapphire sucked below the workpiece suction head. After the substrate surface is adsorbed by the arm 4a, the pressure reduction of the work adsorption head 22 is released, and then the arm 4a of the articulated arm type work transfer robot is moved onto the spin cleaner 11a on the back surface of the lapping work, , placed on a spinner provisional table 11a _t toward the lapping surface of the workpiece upward by releasing the vacuum of the arm.

  25). The spin cleaning of the work is performed while spraying the cleaning water on the front and back surfaces of the work using the spin cleaning device 11a and the Berglin cleaning device 11b, and the cleaning water adhering to the work is wiped off with Berglin.

26). After moving the arm 4a of the articulated arm-type workpiece transfer robot 4 onto the spin cleaner 11a on the back surface of the lapping workpiece, the arm is decompressed to adsorb the lapping surface of the workpiece, and then the articulated arm type The arm 4a of the workpiece transfer robot is transferred into the shelf of the storage cassette 3, where the decompression of the arm 4a is released and a workpiece having a sapphire substrate thickness of 310 μm is stored in the storage cassette 3.

  27). The arm 4a of the articulated arm type work transfer robot 4 is transferred onto the arm cleaner 10 for the articulated arm type work transfer robot, and the arm is cleaned. After cleaning, the arm 4a is returned to the arm standby position of the articulated arm type work transfer robot.

  28). During the steps 20) to 27), the metal rotating surface plate 21 is rotated in the lapping chamber 2c, and cleaning water is supplied from the metal rotating surface plate cleaning device 27. The metal rotating surface plate is cleaned, and the lower part of the workpiece suction head 22 is cleaned by the workpiece suction head cleaner 25. Further, the grooving repair processing of the surface of the metal rotating surface plate 21 is performed by the facing device 28 while the workpiece is not lapping.

  The warping of the 6-inch sapphire substrate having a thickness of 310 μm, which was flattened and the easy-release tape was removed, was about 1.2 mm.

  The flattening apparatus for a sapphire substrate according to the present invention can perform grinding and polishing of a sapphire substrate surface with high throughput without causing cracks. Further, the warping of the flattened sapphire substrate obtained is small, and an annealing process step conventionally performed after grinding or lapping is not necessary.

DESCRIPTION OF SYMBOLS 1 Substrate flattening processing device 2a Work conveyance / work washing chamber 2b Grinding chamber Lapping chamber 2c Lapping chamber 3 Storage cassette 4 Articulated transfer robot 5 Temporary table 20 with centering device Lapping machine 21 Metal rotating surface plate 22 Workpiece suction head 30 Grinding device 31 Index tables 34a, 34b, 34c, 34d Suction chuck table s ₁ Loading / unloading stage s ₂ Coarse grinding stage s ₃ Medium finish grinding stage s ₄ Finish grinding stage 34h _c Coarse grinding wheel Head 34h _m Finishing grinding wheel head 34h _f Finishing grinding wheel head

Claims (2)

The room in which the flattening machine is installed is directed from the front part to the rear part, the front left half of the room is divided into the work transfer room and work washing room, the front right half is divided into the work lapping room, and the rear part is divided. Three sections with the workpiece grinding room
The workpiece transfer chamber / work washing chamber has a plurality of workpiece storage cassettes in the front row from the front to the rear,
In the second row, an articulated arm type work transfer robot in the center,
In the third row, from left to right,
In the first row on the left side, a workpiece suction transporter that can slide the second guide rail on the upper wall of the club room,
A temporary mounting table in front of the second row, a roll rotary work surface washer in the rear of the second row,
An arm washer for an articulated arm type work transfer robot behind the articulated type work transfer robot in the third row,
In the 4th row, there is a spin cleaner on the back side of the lapping workpiece and a Bergrin cleaner for the lapping workpiece surface.
In the fourth row, from left to right,
Provided on the right side of the workpiece adsorption transporter and behind the roll rotary workpiece surface cleaner is a ground workpiece spinner cleaner,
A temporary table with a centering device is provided on the right side of the spinner cleaner for the ground workpiece and behind the arm cleaner for the articulated arm-type workpiece transfer robot,
A work entrance window is provided on the left side wall of the four walls surrounding the lapping chamber in the right front half portion, and a lapping head for a metal rotating surface plate is provided in the lapping chamber. A pair of work pressing means provided so as to be able to swing on the lifting and rotating shafts, a pair of work suction head cleaning devices provided with a rotating brush for cleaning the lower part of the workpiece suction head, and two metal rotating surface plate rings It is equipped with a conditioner, a metal rotating surface plate washing mechanism, and a metal rotating surface plate facing device.
In the rear grinding chamber,
One index table, and a driving means for rotationally driving the rotation shaft of the index table;
Four suction chuck tables provided in four cylindrical punching spaces installed at equal intervals on the same circumference centered on the rotation axis of the index table, and the rotation shafts of the four suction chuck tables are rotated. Driving means for driving,
Of the four suction chuck tables, the first suction chuck table located near the temporary work table with the grinding work washer and centering device in the work transfer chamber / work washing chamber is positioned at the loading / unloading stage (s ₁ ). The L-shaped side wall and the ceiling of the left half of the wall surrounding the loading / unloading stage (s ₁ ) position are deleted, and an up and down arm is provided on the top of the wall. A first work transfer mechanism having a first guide rail capable of moving between a center point and the center point of the temporary table with the centering device is provided, and loading / unloading is performed by the first suction chuck table and the first work transfer mechanism. Configure stage (s ₁ )
Above the second suction chuck table, a rough grinding head in which a cup wheel type rough grinding wheel is supported on the grinding wheel shaft is provided, and the second suction chuck table and the rough grinding head constitute a rough grinding stage (s ₂ ).
The third suction chuck Above the table provided finish grinding head in which the finish grinding wheel in a cup-wheel is journalled in the wheel spindle third suction chuck table and semi-finish grinding head and a medium finish grinding stage (s ₃₎ Configure
and,
Above the fourth suction chuck table, a finish grinding head having a cup wheel type finish grinding wheel supported by a grinding wheel shaft is provided, and the fourth suction chuck table and the finish grinding head constitute a finish grinding stage (s ₄ ). Set up a stage,
Next to the first suction chuck table constituting the loading / unloading stage (s ₁ ), there is provided a pendant swing rotation type work suction transport pad mechanism in which a suction pad is supported by an arm. Installed to swing and rotate between one suction chuck table and the spin cleaner of the ground workpiece,
The arm of the articulated arm type workpiece transfer robot in the workpiece transfer chamber / work washing chamber described above includes a storage cassette, a temporary table with a centering device, a grinding workpiece cleaning device, a temporary table, and a lapping workpiece surface cleaning device. It is possible to move a trajectory that can transport the workpiece adsorbed to the upper workpiece and the lower part of the pair of workpiece adsorbing heads, and to move a trajectory that can transport the workpiece to these devices,
The workpiece suction and transfer device that can slide on the second guide rail in the workpiece transfer chamber and workpiece cleaning chamber is on the line connecting the center point of the temporary table, the roll rotary workpiece surface cleaner, and the center point of the spinner cleaner. Designed to move,
A flattening apparatus for a sapphire substrate. A flattening method for a sapphire substrate, characterized by using the flattening apparatus according to claim 1 to flatten the surface of the sapphire substrate through the following steps to reduce the thickness of the sapphire substrate.
1) Transfer the sapphire substrate (workpiece) with the easily peelable adhesive tape in the storage cassette on the surface onto a temporary table with a centering device using an articulated arm-type workpiece transfer robot. Place the workpiece on.
2). The workpiece on the temporary table with the centering device is transferred onto the first suction chuck table by using the workpiece first transport mechanism so that the easily peelable adhesive tape surface of the workpiece is the lower surface and the sapphire substrate surface is the upper surface. The workpiece is placed on the first suction chuck table.
3). The index table is rotated 90 degrees to move the first chuck table on which the workpiece at the loading / unloading stage (s ₁ ) position is mounted to the second chuck table position at the rough grinding stage (s ₂ ) position.
4). Rotate the second chuck table, then rotate and lower the rough grinding head to bring the cup wheel type rough grinding wheel into contact with the sapphire substrate surface of the workpiece and rub it to start the rough grinding process. Rough grinding is performed by lowering the rough grinding wheel and performing in-feed grinding of the sapphire substrate surface.
5). The index table is rotated 90 degrees to move the second chuck table at the rough grinding stage (s ₂ ) position to the third chuck table position at the intermediate finish grinding stage (s ₃ ) position.
6). Rotate the third chuck table, then rotate and lower the semi-finishing grinding head to bring the cup wheel type semi-finishing grinding wheel into contact with the sapphire substrate surface of the workpiece and rub it to start the semi-finishing grinding process. The cup wheel type intermediate finishing grinding wheel is lowered to perform intermediate finishing grinding for in-feed grinding of the sapphire substrate surface.
7). The index table is rotated 90 degrees clockwise to move the third chuck table at the intermediate finish grinding stage (s ₃ ) position to the fourth chuck table position at the finish grinding stage (s ₄ ) position.
8). Rotate the fourth chuck table, then rotate and lower the finish grinding head to bring the cup wheel type finish grinding wheel into contact with the sapphire substrate surface of the workpiece and rub it to start the finish grinding process. Finish grinding is performed by lowering the finish grinding wheel and performing in-feed grinding of the sapphire substrate surface.
9). The index table is rotated 90 degrees clockwise or 270 degrees counterclockwise, and the fourth chuck table at the finish grinding stage (s ₄ ) position is positioned at the loading / unloading stage (s ₁ ) position. Move to the chuck table position.
10). After moving the ground workpiece mounted on the first chuck table at the loading / unloading stage (s ₁ ) position onto the workpiece spinner cleaner using the workpiece suction transfer pad mechanism, the workpiece is Place on the work spinner cleaner.
11). The workpiece is spin cleaned while spraying cleaning water onto the workpiece surface ground by the workpiece spinner cleaner.
12). The workpiece suction / conveying device is moved back on the second guide rail and moved onto the spinner cleaner of the workpiece, and the ground and cleaned surface of the workpiece placed on the spinner cleaner is sucked.
13). The work suction / conveyance device is moved back on the second guide rail and passed over the roll rotary work surface cleaning device, and the tape surface on the back surface of the work is roll cleaned.
14). The workpiece suction transporter is further retracted on the second guide rail and stopped on the temporary table, and the workpiece is placed on the temporary table with the tape surface of the workpiece facing down and the grinding / cleaning sapphire substrate surface facing up. Put.
15). Using the articulated arm type work transfer robot, the grinding / cleaning sapphire substrate surface is transferred to a position below the work suction head in the lapping chamber, and the work sticking surface of the work suction head is directed upward. Deliver the work downward.
16). The work arm is rotated onto the metal rotating surface plate by rotating the revolving arm of the work suction head.
17). The workpiece newly placed on the temporary table with the grinding / cleaning sapphire substrate surface facing upward is below the vacant workpiece suction head in the lapping chamber using the articulated arm-type workpiece transfer robot. The workpiece is transferred to a position, and the workpiece is delivered below the workpiece suction head with the tape application surface of the workpiece facing upward.
18). The revolving arm of the work suction head is rotated to position the work on the metal rotating surface plate.
19). A pair of the workpiece suction heads are lowered to bring the sapphire substrate surface of the workpiece into contact with the metal rotating surface plate and rubbed to start lapping of the two workpieces, and a desired lapping allowance amount is obtained. When lapping is performed, the rotation of the metal rotating surface plate is stopped and the pair of the workpiece suction heads are raised, and then the swing arm of the workpiece suction head is rotated in the opposite direction to the workpiece suction head standby position. Return to ending lapping.
20). Move the arm of the articulated arm-type workpiece transfer robot below the workpiece suction head, and then suck the workpiece lapping sapphire substrate sucked below the workpiece suction head with the arm and then suck the workpiece Release the pressure reduction of the head, and then move the arm of the articulated arm type work transfer robot onto the spin cleaner on the back surface of the lapping workpiece, where the pressure reduction of the arm is released and the lapping surface of the workpiece is moved. Place it on the spinner temporary table.
21). The spin cleaning of the workpiece is performed while spraying cleaning water on the front and back surfaces of the workpiece using the spin cleaner and the Berglin cleaner, and the cleaning water adhering to the workpiece is wiped off with Berglin.
22). Using the articulated arm-type workpiece transfer robot, the workpiece on the spin cleaner on the back of the lapping workpiece is gripped or sucked, and then the workpiece is stored in a storage cassette.
23). The arm of the articulated arm type work transfer robot is transferred onto the arm cleaner for the articulated arm type work transfer robot, and the arm is cleaned.
24). Move the arm of the articulated arm-type workpiece transfer robot whose arm has been cleaned to the lower side of the other workpiece suction head, and then wrap the sapphire substrate surface of the workpiece sucked under the workpiece suction head. Then, the arm of the articulated arm type work transfer robot is moved onto the spin cleaner on the back surface of the lapping workpiece, and is placed on the spinner temporary table with the lapping surface of the workpiece facing up.
25). The spin cleaning of the workpiece is performed while spraying the cleaning water on the front and back surfaces of the workpiece using the spin cleaner and the Berglin cleaner, and the cleaning water adhering to the workpiece is wiped off.
26). The arm of the articulated arm type work transfer robot is moved onto a spin cleaner on the back surface of the lapping work, and after gripping or adsorbing the work, the arm of the articulated type arm type work transfer robot is moved to a shelf of a storage cassette. The workpiece is transferred into the storage cassette and stored in the storage cassette.
27). The arm of the articulated arm type work transfer robot is transferred onto the arm cleaner for the articulated arm type work transfer robot, and the arm is cleaned.
28). While the steps 20) to 27) are being performed, the metal rotating surface plate is rotated in the lapping chamber, and the cleaning water is supplied from the metal rotating surface plate washer to the metal rotating surface plate. In addition, the lower part of the workpiece suction head is cleaned by the workpiece suction head cleaner.

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