This invention relates to a polishing and cleaning compound device which polishes and cleans both surfaces of a thin disc-shaped work piece in series such as a substrate for magnetic discs, a wafer, a glass substrate for a liquid-crystal display and a glass substrate for photomask.
JP 2002-254301 A discloses a polishing device which holds careers having a plurality of holes for holding a plurality of work pieces between upper and lower press pratens and makes them revolve and rotate on its own axis in normal and inverse directions alternatively to polish both sides of a plurality of work pieces.
JP 2001-144057 A discloses that, for example, a process for polishing surfaces of wafers is constituted of a plurality of polishing processes such as a rough polishing process, a precise polishing process, and a finish process, whose problem is to well remove slurry which is clung on wafers when the wafers are moved between the polishing stations. Accordingly, the patent reference discloses that the wafers are washed in a condition held on holding heads and washed in a condition installed on a holding base, and further, that the holding heads are washed independently.
Currently, there is a demand to polish a large number of thin disc-shaped work pieces such as wafers, and up to now, as disclosed in JP 2002-254301 A, a plurality of work pieces are polished once by making a plurality of careers each of which can receive a plurality of work pieces and revolve and rotate on its axis between the upper and the lower press pratens which have polishing surfaces rotating on their axes and on which slurry is supplied. In this case, when the work pieces are taken out after polishing, polished surfaces of the work pieces are changed by the slurry clung thereon, so that a disadvantage arises in that the work pieces must be taken out as soon as possible and qualities of the work pieces are changed according to an order in which the work pieces are taken out.
In addition, as disclosed in JP 2001-144057 A, it is preferable that removal of the slurry is carried out every polishing process, but as a result, a disadvantage arises in that the process is complicated. Furthermore, a disadvantage arises in that abrasive cloth is hardened because of a time interval between the polishing process and the cleaning process, such that a problem of a decrease in a quality of polishing arises.
An object of the invention is to provide a polishing and cleaning compound device in which polishing and cleaning of work pieces can be carried out continuously.
Accordingly, the present invention is that, in a polishing and cleaning compound device in which a polishing device unit for polishing thin disc-shaped work pieces and a cleaning device unit for cleaning the work pieces polished in the polishing device unit are located in series, the polishing device unit is constituted of at least a pair of cylindrical polishing tools on which abrasive cloths are arranged respectively and at least one roller for rotation for limiting an upper position of the work piece and for rotating the work piece on its axis, and further comprises a first holding means for gripping and holding a work piece, which is transported from a container for installing a plurality of work pieces in turn, in a vertical direction by the pair of the cylindrical polishing tools, and a polishing means for making the work piece held by the first holding means rotate in its axis by the roller for rotation and for rotating the pair of the cylindrical polishing tools so as to bring up the work piece.
Besides, the present invention is that, in a polishing and cleaning compound device in which a polishing device unit for polishing thin disc-shaped work pieces and a cleaning device unit for cleaning the work pieces polished in the polishing device unit are located in series, the cleaning device unit comprises second holding means each of which holds a work piece transported from the polishing device unit in turn, a circle-shaped transport means in which the second holding means are arranged equally on circumference thereof, and a cleaning means which comprises a pair of cleaning tools located so as to grip the work piece and make the pair of the cleaning tools rotate and the work piece rotate in its axis.
Furthermore, the present invention is that, in a polishing and cleaning compound device in which a polishing device unit for polishing thin disc-shaped work pieces and a cleaning device unit for cleaning the work pieces polished in the polishing device unit are located in series, the polishing device unit is constituted of at least a pair of cylindrical polishing tools on which abrasive cloth is arranged and at least one roller for rotation for limiting an upper position of the work piece and for rotating the work piece on its axis, and further comprises a first holding means for griping and fixing a work piece, which is transported from a container for installing a plurality of work pieces in turn, in a vertical direction by the pair of the cylindrical polishing tools, and a polishing means for making the work piece held by the first holding means rotate in its axis by the roller for rotation and for rotating the pair of the cylindrical polishing tools so as to bring up the work piece; and the cleaning device unit comprises second holding means each of which holds a work piece transported from the polishing device unit in turn, a circle-shaped transport means in which the second holding means are arranged equally on circumference thereof, and a cleaning means which comprises a pair of cleaning tools located so as to grip the work piece and make the pair of the cleaning tools rotate and the work piece rotate in its axis.
Roughly speaking, in a polishing device unit of a polishing and cleaning compound device, a work piece transported from a container in which a plurality of thin disc-shaped work pieces are installed in turn is gripped and fixed in a vertical direction by a pair of cylindrical polishing tools, being rotated in its axis by the rollers for rotation, being polished by making the pair of the cylindrical polishing tools rotate so as to bring the work piece up. Besides, in a cleaning device unit, the work pieces polished by the polishing device unit are held in turn by a plurality of second holding means arranged on circumference of a circle-shaped transporting mechanism, and then the work pieces are moved to a specific position for cleaning in turn and cleaned by a pair of cleaning tools arranged so as to grip the work piece.
Moreover, it is preferred that the second holding means comprises a plurality of rollers for rotation which are in contact with a circumference edge of the work piece.
Furthermore, it is preferred that the pair of the cylindrical polishing tools are in contact with the work piece linearly at a position with a specific value lower than a horizontal reference line passing through a center point of the work piece and in parallel with the horizontal reference line.
Besides, it is preferred that the pair of the cylindrical polishing tools are in contact with the work piece linearly at a position with a specific value lower than a horizontal reference line passing through a center point of the work piece with inclination to the horizontal reference line at a specific angle, it is preferred that the specific angle is within 5-40°, especially within 10-20°.
It is preferred that at least one roller for rotation in the polishing device unit makes the work piece move (reciprocate) or revolve elliptically so that a center of the work piece passes through an area in contact with the cylindrical polishing tools. Thus, in the case that the work piece is thin disc-shaped and does not have an opening at a center thereof, it is possible to polish evenly as a whole.
Another object of the invention is to provide a polishing and cleaning compound device which can carry on cleaning at the same time that polishing is finished.
Accordingly, the present invention is that a polishing and cleaning compound device comprises at least a transport means for transporting thin disc-shaped work pieces, polishing tools for polishing a work piece transported by the transport means and a drive means for driving the polishing tools to the work piece, driving the polishing tools to the work piece by the drive means, carrying out a polishing process in which abrasive material is poured into the polishing tools and a cleaning process in which cleaning water is poured into the polishing tools continuously.
Therefore, because there is no time interval from the polishing process to the cleaning process, the above problem can be achieved.
Furthermore, it is preferred that the polishing process and the cleaning process are overlapped at a specific time to be carried out. Thus, shift from the polishing process to the cleaning process can be carried out smoothly.
Moreover, the polishing tools are a pair of cylindrical polishing tools in which abrasive cloth is arranged, the work piece transported by the transport means is gripped and fixed in a vertical direction to be rotate, the pair of the cylindrical polishing tools is rotated so as to bring the work piece up, the polishing process is carried out by pouring abrasive material into the pair of the cylindrical polishing tools, and the cleaning process is carried out by pouring cleaning water into the pair of the cylindrical polishing tools.
Besides, it is preferred that the transport means takes out a work piece from a container in which the work pieces are installed in turn to transport it, and transports the polished and cleaned work piece to next processes in turn.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matters in which there are illustrated and described preferred working modes of the invention.
Hereinafter, the best working modes of the invention are explained according to the drawings.
A polishing and cleaning compound device 1 according to a working mode of the present invention includes at least a polishing device unit 2 and a cleaning device unit 3.
A thin disc-shaped work piece 5 such as a substrate for a magnetic disc, a semiconductor wafer, a glass substrate for liquid-crystal display, and a glass substrate for a photomask which is installed in a container 4 is gripped by a grip 6a of a lift mechanism 6 and lifted up from the container 4. A career 7 moves to a position where a first holder 7a of the career 7 reaches under the grip 6a, and in this position, the career 7 moves up to receive the work piece 5 on the first holder 7a from the grip 6a.
After the work piece 5 is set on the first holder 7a, the career 7 moves horizontally to a position where the first holder 7a reaches under a polishing mechanism 20, and in the position, the career moves up. The polishing mechanism 20 holds the work piece moving up with the career
The polishing mechanism 20 comprises, as shown in
In the above constitution, the cylindrical polishing tools 22 grip the work piece at the contact line S and rotate so as to urge the work piece 5 upward, and further, the rollers for rotation 21 make the work piece 5 rotate on its axis, so that both sides of the work piece 5 can be polished. Note that in this polishing process, slurry with specific characteristics is supplied to a polishing cloth provided on the outer surfaces of the cylindrical polishing tools 22.
After the polishing process, the career 7 moves to the left in
The cleaning device unit 3 comprises a circle-shaped transporting mechanism 10 which has a plurality of holding mechanisms 30 arranged at specific intervals on a circumference thereof, and at least one cleaning mechanism 40 (in this working mode, two cleaning mechanisms) which is provided at a specific position of the circle-shaped transporting mechanism 10. The circle-shaped transporting mechanism 10, which is constituted as a Ferris wheel shape, rotates the work pieces 5 gripped by the holding mechanisms 30 at every specific angle (in this working mode, 45°) to transport the work pieces 5 to the cleaning mechanism 40, and after cleaning, further transports the work pieces 5 to the transporting mechanism 9 while drying the work pieces 5 in turn.
Each of the holding mechanisms 30 in the cleaning device unit 3 is constituted of three holding rollers 31 which hold the work piece 5 at at least three points. In this case, a power holding the work piece 5 can be increased by applying a rotation power to the holding rollers 31 located on both sides so as to urge the work piece 5 to the holding roller 31 located in the middle.
The cleaning mechanism 40 is, as shown in
The polished and cleaned work piece 5 transported to a specific position with the circle-shaped transporting mechanism 10 rotating is transferred from the holding mechanism 30 by a grip 9a of the transporting mechanism 9 to be installed into the container 4.
Thus, in the polishing and cleaning compound device 1 according to the present invention, the work pieces 5 installed in the container 4 can be polished and cleaned in series, and then, installed into the container 4 again, so that constant quality can be maintained and productivity can be increased.
The polishing mechanism 20 according to another working mode shown in
This shows, for instance, as shown in
Due to the above factors, because swinging of the work piece 5 can be prevented, polishing precision can be increased more than the above mentioned first working mode and polishing performance can be steadied. It is preferred that the angle a is within 5-40°, and especially within 10-20°.
In a polishing mechanism 20 according to a third working mode as shown in
Furthermore, in a polishing mechanism according to a fourth working mode as shown in
Also, by moving the rollers for rotation 21 so as to push the work piece 5 down against a rotation power of the cylindrical polishing tools 22 and then return to the original positions thereof at the moment, the center of the work piece 5 can be passed through the polishing area of the cylindrical polishing tools 22. Furthermore, at this time, though the work piece 5 moves horizontally at the moment, the horizontal movement of the work piece 5 can make a polished condition near the center of the work piece 5 better.
A polishing and cleaning compound system 1 according to the fifth working mode is constituted of at least a polishing and cleaning compound device 2, a device for cleaning only 3 and transport devices (6,7,8,9,10) the same as mentioned above.
In the polishing and cleaning compound system 1 according to the fifth working mode, the polishing/cleaning mechanism 20 is provided with a tank for hosing abrasive 23 with an on-off valve 24 and a tank for washing water 25 with an on-off valve 25, wherein a polishing process is carried out when the abrasive with any specific characteristics is supplied to polishing cloths provided on side surfaces of the cylindrical polishing tools 22 by turning the on-off valve 24 on and a cleaning process is carried out when the washing water is supplied to the polishing cloths by turning the on-off valve on.
After processes in the polishing/cleaning mechanism 20, cleaning the work piece 5 is carried out in the device for cleaning only 3 similarly to the above working modes, and finally the work piece 5 is installed in the container 4. Hereinafter, in this working mode, the same reference numbers are marked on parts in this working mode similar to ones in the above working modes to omit explanation thereof, and actions of the polishing/cleaning mechanism 20 are explained especially.
In the polishing and cleaning compound system 1 according to the fifth working mode, an operation, for instance, as shown in a flowchart of
Firstly, the cylindrical polishing tools 22 is driven at a low rotation speed in step 100, and then, in step 120, the transporting devices 6, 7 are driven in order to hold the work piece 5 between the cylindrical polishing tools 22 rotating at the low rotation speed. These steps 110 and 120 constitute a preparation stage 100.
After holding the work piece 5, the cylindrical polishing tools 22 are driven at a high rotation speed in step 210, the abrasive is poured on the polishing cloths of the cylindrical polishing tools 22 by turning on the on-off valve 24 in step 220, so that a polishing stage 200 of the work piece 5 is carried out. The polishing stage 200 is terminated by turning off the on-off valve 24 to stop pouring the abrasive, and a cleaning stage 300 is started by turning on the on-off valve 26 to pour washing water. The cleaning stage 300 is terminated by turning off the on-off valve 26 to stop pouring the washing water.
Thus, the present invention is characterized in that the polishing stage is carried out by pouring the abrasive and the cleaning stage is carried out by pouring the washing water while the cylindrical polishing tools 22 rotate, that is to say, the cleaning stage is started while the polishing stage is being terminated. Accordingly, a disadvantage which arises from a time gap between the termination of the polishing stage and the start of the cleaning stage, such as to change the polished surface by the abrasive clung on the work piece, can be prevented, so that a quality thereof can be increased.
Next, a continuation of working in step 410 is judged, and in the case that the working is continued (Y), the processes from step 110 to step 320 are carried out repeatedly by returning to step 110, so that polishing of the work pieces 5 is carried out in series. In step 410, in the case that it is judged that working is not continued (N), the cylindrical polishing tools are driven at a low rotation speed in step 420, the transporting device 6, 7 are driven in step 430 to transport the last working piece 5 to the next process, and then the cylindrical polishing tools 22 are stopped in step 440 to terminate the working in the polishing/cleaning mechanism 20.
In
As explained above, according to this invention, the polishing device unit and the cleaning device unit are arranged in series and the polishing process and the cleaning process are carried out in series in turn, so that continuous workings become possible, as a result, the quality and the productivity of the work pieces can be increased.
In addition, in the cleaning process, the front and the back surface of the polished work piece are not gripped, but the circumferential edge of the work piece is held at points thereof, so that the quality of the work piece can be increased.
Furthermore, according to this invention, because the cleaning process is started by changing from pouring the abrasive to pouring the washing water without stopping machines from the polishing process, the abrasive does not remain on the polished surfaces thereof, so that a disadvantage by clinging of the abrasive can be avoided. In addition, dressing of the polishing cloths can be carried out by pouring the washing water at the same time, and a surface of the polishing cloth can be held in a good condition. As a result, quality of polishing can be maintained for a long time.
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2002-345348 | Nov 2002 | JP | national |
2003-026759 | Feb 2003 | JP | national |
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