JPH10277924A - Temperature holding structure for rotary table - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a uniform temperature distribution of a surface to be polished for a long time by spirally arranging a heating medium conduit for supplying the heating medium from an opening provided in one end in a heating medium storage chamber. SOLUTION: Cooling water in a circular chamber 134 which is heat exchanged with a surface 152 to be polished and is so set as increasing the temperature toward an internal circumferential side is heat exchanged with cooling water in a cooling water conduit 128. The cooling water in the cooling water conduit 128 spirally flows toward the outer circumferential side in the ring chamber 134, while heat exchanged with the cooling water in the ring chamber 134 so that the temperature tends to be increased toward the outer circumference where the temperature of the cooling water in the ring chamber 134 is low. The temperature increase inclination of the cooling water in the ring chamber 134 is thus offset by the temperature increase inclination of the cooling water in the reverse-direction in the cooling water conduit 128. The temperature of the cooling water in the ring chamber 134 becomes approximately uniform in the diametrical direction so that the heat exchange quantity of the cooling water and the surface 152 to be polished can be held approximately uniformly in the diametrical direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a temperature holding structure of a rotary platen used for lapping, polishing and the like.

[0002]

2. Description of the Related Art A lapping process or a polishing process in which an object to be polished is brought into sliding contact with a polishing surface by rotating a disk-shaped polishing surface plate having a flat polishing surface on one surface and rotating the polishing surface around an axis. It has been known. In processing using such a polishing surface plate, polishing heat is likely to be generated because the object to be polished is constantly in contact with the polishing surface. Further, heat generated from a power system or a drive system provided in the lapping device, that is, heat generated by a motor, or heat generated by sliding or friction of a bearing portion is also transmitted to the polishing platen. Therefore, if the polishing platen is thermally expanded by polishing heat or heat generated from a drive system (hereinafter collectively referred to as polishing heat, etc.) and the flatness is reduced, high processing accuracy cannot be obtained. When performing processing or the like, the polishing table is cooled and maintained at a constant temperature in order to maintain a thermal equilibrium state on the polishing surface.

Conventionally, as a method for cooling the above-mentioned polishing table, generally, a cooling chamber having a supply port and a discharge port is provided inside the polishing table, and a cooling liquid such as water or a grinding fluid is provided in the cooling chamber. It is being distributed. In such a cooling method, the temperature of the cooling liquid supplied from the supply port is gradually increased by heat conduction between the cooling liquid and the polishing surface while flowing through the cooling chamber and being discharged from the discharge port. Therefore, the temperature difference from the polished surface near the discharge port becomes smaller,
While a large cooling effect is obtained near the supply port, the cooling effect is small near the discharge port. For example, in a platen with a size of about φ300 (mm) or less, the temperature distribution of the polished surface generated due to the difference in cooling effect remains within a range that does not affect the processing accuracy. In the case of a polishing platen having a size as large as about (mm) or φ1000 (mm), there is a problem that a large temperature distribution is generated on the polished surface and processing accuracy is reduced. Therefore, various cooling structures have been proposed for the purpose of obtaining a uniform cooling effect over the entire polishing surface of a large surface plate.

[0004]

For example, Japanese Utility Model Publication No. 60-
In the surface plate of the lapping device described in Japanese Patent No. 21172, the inside of the surface plate is divided into a plurality of fan-shaped cooling chambers 10 as shown in FIG. A partition 12 for dividing the two chambers 10a and 10b into communication with each other is provided.
A cooling liquid supply port 14 and a cooling liquid discharge port 16 are provided on the inner peripheral side of a and 10b, respectively. This coolant supply port 14
The coolant supplied to the inside of the one chamber 10a flows into the other chamber 10b via the communication portion 18 on the outer peripheral side, and is discharged from the coolant discharge port 16. The plurality of cooling chambers 1
0 and a chamber 10b provided with a coolant supply port 14 and a coolant supply port 16 respectively.
Are arranged every other in the circumferential direction. For this reason,
Since the cooling conditions of the plurality of cooling chambers 10 arranged in the circumferential direction are the same, and the cooling liquid passage is formed so as to reciprocate in the radial direction by the two chambers 10a and 10b, the cooling chamber 10 in each cooling chamber 10 is formed. The cooling conditions in the radial direction are also substantially uniform.

Further, in the surface plate of the flat surface polishing apparatus described in Japanese Patent Publication No. Hei 7-35015, the inside of the surface plate is divided into a plurality of fan-shaped cooling chambers 20 as shown in FIG. A coolant supply port 22 is provided on the outer peripheral side of each cooling chamber 20.
However, a coolant discharge port 24 is provided on the inner peripheral side. For this reason, also in this surface plate, the cooling conditions of the plurality of cooling chambers 20 arranged in the circumferential direction are the same as in the case of the surface plate shown in FIG. In each of the cooling chambers 20, the coolant flows from the outer periphery toward the inner periphery. However, the number of divisions in the circumferential direction and the coolant are set so that the circulation speed of the coolant is sufficiently high. Since the temperature distribution in the radial direction can be suppressed to some extent by appropriately setting the supply amount, this may be performed if the required processing accuracy is not so high.

Further, as shown in FIG. 3, the interior of the surface plate comprises four fan-shaped cooling chambers A, B, C, and D, respectively, which communicate with each other through a communication hole (not shown).
There is also proposed a structure in which two cooling chamber groups a, b, and c are divided into a total of 12 cooling chambers 26. In the surface plate, the cooling liquid is individually supplied to the cooling chamber groups a, b, and c, and the cooling liquid flows through the cooling chambers A, B, C, and D in order, and is discharged. That is, for example, for the cooling chamber group a, the cooling liquid supplied to the cooling chamber 26aA from a supply port (not shown)
B, 26aC, flows into the cooling chamber 26aD, and is discharged from the cooling chamber 26aD to the outside of the surface plate through a discharge port (not shown). In addition, the relative positions of the plurality of cooling chambers 26 are such that the cooling chambers A and B, which can obtain a high cooling effect because they are on the upstream side, are adjacent to both circumferential sides of the other cooling chamber group D having the lowest cooling effect. It is determined as follows. For this reason, a substantially uniform temperature distribution is also formed in the circumferential direction in the surface plate. In addition, since the cooling chamber 26 is composed of three groups, the number of coolant supply / discharge pipes is smaller than that of the three systems and the number of divisions of the cooling chamber 26, so that the piping structure of the wrapping device and the like is simplified. There is also an advantage.

As shown in FIG. 4, a plurality of outer partition walls 28 are provided alternately in the circumferential direction and extend from the outer peripheral end toward the inner peripheral side. Plural inner peripheral partitions 30 extending toward
A labyrinth that reciprocates in the circumferential direction by meandering over the entire surface of the inside of the surface plate by the intermediate wall 32 that is provided in a meandering manner in the circumferential direction passing between the outer peripheral side partition 28 and the inner peripheral side partition 30. A structure in which the cooling liquid passage 34 is formed has also been proposed.
At both ends of the coolant passage 34, a supply port 36 and a discharge port 3 are provided.
The cooling liquid supplied from the supply port 36 reciprocates in the circumferential direction while meandering inside the surface plate, and is discharged from the discharge port 38. Therefore, the coolant passage 3
4 meanders, the radial temperature distribution becomes substantially uniform at each of the arbitrary circumferential positions, and the coolant passage 3
4 reciprocates in the circumferential direction, so that a substantially uniform temperature distribution is also formed in the circumferential direction.

However, the conventional cooling structure for a surface plate as described above has various disadvantages as described below. First, since the plurality of cooling chambers 10, 20, and 26 are provided in each of the bases shown in FIGS. 1 to 3, a plurality of cooling chambers 10 and the like are required to make the circumferential temperature distribution uniform. The supply and discharge of mutual coolant must likewise be maintained. In other words, it is necessary that the flow resistances of the small coolant supply port 14 and the small coolant discharge port 16 provided in each of the plurality of cooling chambers 10 and the like are kept the same in the cooling chambers 10 and the like. Therefore, the coolant supply port 14 may be damaged by rust or scale (precipitated and fixed matter of impurities) mixed in the coolant.
When the flow resistance is increased due to the blockage or the hole diameter is reduced, the cooling liquid is not sufficiently supplied to some of the cooling chambers 10 and the like, and the cooling effect cannot be obtained partially or may be low. Therefore, there is a problem that a stable cooling effect and a uniform temperature distribution cannot be obtained over a long period of time.
This problem becomes more remarkable because as the number of divisions of the cooling chamber 10 and the like is increased to make the temperature distribution as uniform as possible, the coolant supply port 14 and the like must be smaller.

Further, in the surface plate shown in FIG. 4, since only one cooling liquid passage 34 is provided, the size of the supply port 36 and the discharge port 38 is limited by the above-described blockage and flow resistance. By increasing the temperature to a level that hardly causes a problem, a stable temperature distribution can be obtained over a long period of time. However, in order to form such a complicated coolant passage 34, there is a problem that a complicated mold is required when casting a surface plate, and the production cost is increased. In addition, as another example of the surface plate provided with the coolant passage that reciprocates in the circumferential direction, for example, as shown in FIG. A system for flowing a cooling liquid is disclosed in Japanese Patent Application Laid-Open No. 58-44956. According to this structure, a coolant passage having the same function as that shown in FIG. 4 can be formed at low cost. However, since the pipe 40 is directly cooled by the coolant, a sufficient polishing surface can be obtained. In order to obtain a sufficient cooling effect, it is necessary that the tube 40 and the component on the polishing surface side of the platen be in close contact. Therefore, since the tube 40 is embedded in the surface plate at the time of casting so that the tube 40 is brought into close contact with the structure in the surface plate, repair becomes impossible when the tube 40 is closed, and the polished surface is worn. However, there is a problem that the surface plate can no longer be used. Note that the above problem is not limited to the case where the surface plate is cooled, and may similarly occur when the temperature of the polished surface is maintained at an appropriate temperature by supplying a heating medium having a desired temperature into the surface plate. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rotating mechanism capable of obtaining a uniform temperature distribution of a polished surface over a long period of time with a simple structure. An object of the present invention is to provide a temperature maintaining structure for a panel.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide a disk having a flat polished surface on one side and being driven to rotate around an axis. A rotary platen for processing an object to be polished to be slid in contact with the polishing surface, a temperature holding structure for holding the polishing surface at a predetermined temperature, (a) a predetermined inside the rotary platen A liquid-tight heat medium storage chamber in which a heat medium for maintaining the polishing surface at a predetermined temperature based on heat conduction is stored, the liquid medium being provided continuously in an annular shape with a radial width dimension in the circumferential direction, (b)
A heating medium conduit for supplying a heating medium into the heating medium storage chamber through an opening provided at one end, the heating medium conduit being disposed in a spiral shape continuously in the circumferential direction in the heating medium storage chamber; And a discharge port for discharging the heat medium in the heat medium storage chamber to the outside of the rotary platen.

[0012]

According to the above construction, a circular surface is provided continuously in the circumferential direction with a predetermined radial width inside the rotary platen, and the polished surface is maintained at a predetermined temperature based on heat conduction. A liquid-tight heat medium storage chamber in which the heat medium is stored, and the heat medium storage chamber is disposed in a spiral shape continuously in the circumferential direction in the heat medium storage chamber, and a heat medium is supplied into the heat medium storage chamber from an opening provided at one end. The heat medium conduit for supplying and the opening of the heat medium conduit in the heat medium storage chamber are provided on the opposite side in the radial direction, and an outlet for discharging the heat medium in the heat medium storage chamber out of the rotary platen. And the temperature holding structure of the rotary platen is configured. Therefore, the temperature holding structure of the rotary platen has a simple structure in which an annular heat medium storage chamber is provided in the platen and a spiral heat medium conduit is disposed therein. The polished surface of the rotating platen exchanges heat with the heat medium stored in the heat medium storage chamber. The heat medium is a heat medium spirally disposed in the heat medium storage chamber. The heat is exchanged with the heat medium flowing through the conduit, and the heat medium is replaced by the heat medium supplied from the opening of the heat medium conduit, and is sequentially discharged from the outlet. At this time, since the heat medium conduit is spirally arranged in the heat medium storage chamber,
The heat medium in the heat medium storage chamber is substantially uniformly heat-exchanged with the heat medium in the heat medium conduit in the circumferential direction, and the heat medium storage chamber is formed continuously in the circumferential direction and has a circumferential direction. Is hardly formed, the temperature of the heat medium in the heat medium storage chamber is maintained substantially uniform in the circumferential direction. Further, since the opening of the heat medium conduit and the discharge port are provided on the opposite sides in the radial direction, the heat medium supplied from the opening into the heat medium storage chamber is radially discharged until the heat medium is discharged from the discharge port. The temperature gradient tendency caused by heat exchange with the polishing surface in the process of being moved, and the heat medium in the heat medium conduit being spirally moved and supplied to the heat medium storage chamber through the opening, Since the temperature gradient tendency caused by heat exchange with the heat medium in the storage chamber is opposite to the temperature gradient tendency, the temperature gradient tendency between them is canceled out, and the temperature of the heat medium in the heat medium storage chamber is changed in the radial direction. It is also kept substantially uniform. Further, since the heat medium storage chamber is not divided in the circumferential direction, the flow cross-sectional area of the heat medium, that is, the heat medium conduit, the cross-sectional area of the opening and the discharge port can be formed sufficiently large, and the supply / discharge path is not easily blocked. A temperature holding effect can be obtained over a long period.
Therefore, with a simple structure, the temperature of the heat medium in the heat medium storage chamber is maintained substantially uniform over the entire surface, and the temperature of the polished surface can be uniform over a long period of time. The temperature holding structure of the rotating platen can be obtained.

[0013]

In another embodiment of the present invention, preferably, the heat medium conduit is provided such that portions adjacent in the radial direction over substantially the entire width of the heat medium storage chamber are substantially in close contact with each other. is there.
With this configuration, compared with the case where the heat medium conduits are arranged so that a large gap is formed between them, the heat medium between the heat medium in the heat medium storage chamber and the heat medium in the heat medium conduit is different. Since the amount of heat exchange is sufficiently increased, the temperature distribution in the heat medium storage chamber can be made more uniform.

Preferably, the opening of the heat medium conduit is provided at an outer peripheral position of the heat medium storage chamber, and the discharge port is provided at an inner peripheral position of the heat medium storage chamber. It is. With this configuration, while the heat medium is supplied to the outer circumferential position of the heat medium storage chamber by the heat medium conduit, the heat medium is discharged from the inner circumferential position, so that the heat medium formed in the surface plate is formed. The medium discharge path can be made simple, and the manufacture of the rotary platen having the temperature holding structure is further facilitated.

Preferably, a plurality of the heat medium conduits are provided in the heat medium storage chamber. According to this configuration, since the plurality of heat medium conduits are provided in the heat medium storage chamber, the position of the opening for supplying the heat medium into the heat medium storage chamber may be appropriately set between the plurality of heat medium conduits. By setting, it is easy to secure the balance of the rotary platen. Moreover, since a plurality of heat medium conduits are provided, even when a part of them is closed or the flow resistance of the heat medium becomes high, the heat medium storage chamber is provided by another heat medium conduit. Is supplied to the heat medium, and heat exchange with the heat medium in the heat medium storage chamber is performed substantially uniformly over the entire surface. Therefore, it is possible to maintain a stable temperature for a longer time.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the following examples, the dimensional ratios and the like of each part are not necessarily drawn accurately.

FIG. 6 is a perspective view showing the entirety of a polishing machine 50 having a rotating surface plate having a temperature holding structure according to one embodiment of the present invention. FIG. It is a figure which shows a partial cross section. The polishing machine 50 is for finishing and polishing, for example, a silicon wafer, a glass plate for a liquid crystal panel, a disk for a recording medium, or a quartz plate. In the figure, a polishing machine 50 includes an apparatus main body 56 having a rotating surface plate 54 on which a polishing tool 52 is mounted on an upper surface, a control device 58 mounted on a side portion of the apparatus main body 56, and a constant temperature And a chiller device 60 for supplying the cooling liquid.

In the above-mentioned apparatus main body 56, bearings 62, 6
2 is a rotary spindle 6 rotatably supported about an axis.
4 and a drive motor 66, and the rotation of the drive motor 66 is transmitted to the rotating main shaft 64 by a belt 68 indicated by a chain line in the figure. A flange 70 is provided at an upper end portion of the rotating main shaft 64, and the surface plate 54 is fixed to an upper surface of the flange 70 by a bolt or the like so as not to rotate relatively. The rotating main shaft 64 is provided with a vertical through hole 72 penetrating in the axial direction, and the tubular member 7 is coaxially provided in the vertical through hole 72.
4 are provided. The vertical hole 72 is sealed in a liquid-tight manner in the vicinity of the upper opening 76 by a seal 78 provided between its inner peripheral surface and the tubular member 74. A pair of supply holes 82 each extending in the opposite outer circumferential direction, that is, one diameter direction from the center portion, and having a supply hole 82 for supplying cooling water to the surface plate 54 in the vicinity of the outer peripheral end and opening to the flange surface 80. Are provided branching from the vertical through hole 72. Further, a rotary joint 86 is attached to a lower end of the rotary main shaft 64, and a water supply pipe 88 and a drain pipe 90 extending from the chiller 60 are connected to the vertical through-hole 72 and the tubular member 74 by the rotary joint 86, respectively. I have. Therefore, the vertical hole 72 functions as a water supply channel, and the tubular member 74 functions as a drainage channel.

The platen 54 is, for example, an FCD 70
The base plate 92 is fixed to the flange 70, and bolts 94 (at the outermost periphery in FIG. 7) are provided on the base plate 92 at, for example, a plurality of positions on three positions in a radial direction. (Shown only in one place) is fixed to the surface plate 96, and the entire size is about φ650 × 80 (mm). The base plate 92 is provided with a fitting hole 102 which is fitted on a back surface 98 on the flange 70 side with a fitting projection 100 projecting from the flange surface 80 of the flange 70. A pair of receiving holes 104 that are connected to the pair of supply holes 82 and guide the cooling water into the surface plate 54 are opened on the outer peripheral side of the hole 102. The fitting hole 102 is configured to have a stepped portion 106 by making a part of the inner peripheral side deeper,
In the state fitted with the fitting projection 100, the stepped portion 106 and the flange 7 are provided above the fitting projection 100.
A drainage chamber 108 is formed between the two.

As shown in FIG. 8 corresponding to FIG. 7 and the plan view of the base plate 92, the front surface of the base plate 92 to which the table plate 96 is fixed is, for example, 360 mm in diameter. (mm)
An annular first annular groove 110 having a depth of about 35 (mm) is formed in a range of about 595 (mm) to about 595 (mm).
First at a depth of about 12 (mm) in the range of 5 (mm) to about 305 (mm)
Annular second annular groove 11 smaller in diameter and shallower than annular groove 110
2 are formed. Therefore, when the surface plate 96 is mounted on the base plate 92, the first annular groove 110 and the second annular groove 112 and the substantially flat back surface of the surface plate 96 respectively have an annular shape therebetween. A chamber is formed. The pair of receiving holes 104 extend in the axial direction from the back surface 98 to an intermediate position in the thickness direction of the platen 54, and are bent in opposite directions toward the outer peripheral side along the radial direction. The second annular groove 1
12 and open to the inner peripheral surface 114 of the first annular groove 110. That is, the pair of receiving holes 10
4 are formed so that they are entirely located on opposite sides in the circumferential direction. Further, the first annular groove 110 and the second annular groove 1
12 are separated from each other in the radial direction by a circumferential protrusion 116. The circumferential protrusion 116 has a circumferential length of 20 (mm) over the entire width in the radial direction at four places in the circumferential direction. A notch 118 having a depth of about 5 (mm) is provided. Therefore, the first annular groove 110 and the second annular groove 11
The two annular chambers respectively formed by the two are communicated via the notch portion 118, and are entirely liquid-tight. In addition, the upper surface of the convex portion 120 provided on the inner peripheral side of the second annular groove 112 has four second circumferential portions.
A recess 124 having a length shorter than the radius formed from the inner peripheral surface 122 of the annular groove 112 is provided. This depression 12
4 are through holes 1 penetrating in the axial direction of the base plate 92.
26 communicates with the stepped portion 106 of the fitting hole 102. The notch 118 and the recess 124 are provided at angular positions different from each other by 45 degrees in the circumferential direction, as shown in FIG. 8. It is the same as the notch 118. The peripheral protrusions 116 are provided for the purpose of supporting the front surface plate 96 from the back surface side and supplementing its rigidity.

In the first annular groove 110, a pair of cooling water conduits 128a made of copper (for example, C1020 or the like) having an outer diameter of about 12 (mm) and an inner diameter of about 10 (mm) are provided. 1
28b (hereinafter, unless otherwise specified, simply the cooling water conduit 1
28) is provided so as to draw a spiral in the direction opposite to the rotation direction R of the surface plate 54 shown in FIG. The pair of cooling water conduits 128
The inner peripheral end portions 130 are respectively inserted and fixed in a pair of openings of the pair of receiving holes 104 on the first annular groove 110 side, and the outer peripheral end openings 132 are respectively formed in the inner peripheral end portions 1.
It is located at a circumferential position substantially similar to 30. That is, the outer peripheral end opening 132 is provided with the cooling water conduit 128a,
128b are located on mutually opposite sides in the circumferential direction.
The portion near the inner peripheral side end portion 130 is the first annular groove 11.
After extending from the inner peripheral surface 114 toward the outer peripheral side, it is bent at the outermost peripheral position and returned to the inner peripheral side. This is to reduce the bending angle of the cooling water conduit 128 as much as possible. It is formed for the purpose of making it small and keeping the flow resistance in the pipe accompanying the bending low. For this reason, the whole other spirally formed portion of the cooling water conduit 128 is located above the bent portion as shown in FIG. Also, in FIG. 8, for ease of understanding, the middle part of the cooling water conduit 128b is omitted and only a part of the innermost peripheral part and the outermost peripheral part is shown.
a and 128b are alternately arranged in the radial direction in the first annular groove 110 and provided substantially in close contact with each other, and are integrally fixed at several places in the circumferential direction with an adhesive (not shown) or the like. In the present embodiment, the annular plate 134 formed by the first annular groove 110 in the table plate 96 corresponds to a heat medium storage chamber, and the cooling water conduit 128 corresponds to a heat medium conduit.

For this reason, the water supply pipe 88 from the chiller device 60
When the cooling water is supplied to the main body 56 through the
2, cooling water conduit 12 through branch hole 84, receiving hole 104
8, flows through the cooling water conduit 128 spirally arranged in the first annular groove 110, and is discharged from the outer peripheral end opening 132, so that the first
Cooling water is supplied into the annular groove 110. First annular groove 11
The cooling water supplied into the inner space 0 flows toward the inner peripheral side according to the pressure given from the new cooling water sequentially supplied to the outer peripheral position from the cooling water conduit 128 while flowing along the circumferential direction of the surface plate 54, The gas enters the second annular groove 112 through the notch 118, flows further inward, and flows from the recess 124 through the through hole 126 into the drainage chamber 108. Then, the water is collected from the drain pipe 90 to the chiller device 60 through the inside of the tubular member 74. Therefore, in this embodiment,
The notch 118 corresponds to a discharge port, and the discharge port is provided on a side opposite to the outer peripheral end opening 132 of the cooling water conduit 128 in the radial direction. When using the surface plate 54,
Although the above-mentioned water supply and drainage will be performed continuously, the inner diameter of the cooling water conduit 128 is as large as about 10 (mm) as described above,
The opening cross-sectional area of the notch 118 corresponding to the discharge port is also 10
Since the cooling water flow path is increased to about 20 (mm ² ), clogging of the cooling water flow path due to rust, scale, and the like is less likely to occur.

The polishing tool 52 has a size of, for example, an outer diameter of φ600 (mm) × a thickness of 50 (mm), and has a thickness of, for example, an aluminum alloy or stainless steel. Is about 40 (mm) and the outer diameter is 600 (m
m) × inner diameter 200 (mm) × abrasive layer 140 having a dimension of about 10 (mm) and fixed on substrate 138. The abrasive layer 140 is formed by, for example, bonding diamond abrasive grains with a resin binder such as phenol resin. The polishing tool 52 includes a platen 5
4 is fixed to the front surface of the surface plate 96 with bolts 136 at the center so that the back surface thereof is in close contact with the front surface.

Returning to FIG. 6, a table 142 is provided at an upper portion of the main body 56 at a position on the outer peripheral side of the polishing tool 52 and the surface plate 54.
The correction ring 14 is provided on the table 142.
4 and a plurality of arms 150 for suppressing circumferential movement of the work holder 154 (see FIG. 7) and rotating or swinging the correction ring 144 etc. according to the driving force of the motors 146 and 148. ing. In the figure, motors 146, 1 corresponding to one arm 150 are shown.
Although only 48 are shown, in practice,
The motors 146, 148 are provided in each of the 50.

When performing polishing using the polishing machine 50 configured as described above, first,
After the polishing tool 152 mounted on the surface plate 54 is conditioned using a correction ring 144 to remove the polishing debris and form a predetermined flatness, the polishing tool 52 is rotated about an axis. 7, the workpiece 156 attached to the work holder 154 is brought into sliding contact with the polishing surface 152 as shown in FIG. At this time, when the conditioning and polishing are performed, the cooling water maintained at a constant temperature by the chiller device 60 is supplied into the surface plate 54 through the path, and the spiral cooling water conduit 128a, 128b, and the annular chamber 1
34. Therefore, the platen 54 is the base plate 9
The annular chamber 134 between the table 2 and the table 96 is filled with the cooling water discharged from the cooling water conduit 128.

During conditioning and polishing, the correction ring 144 or the object to be polished 156 is brought into sliding contact with the polishing surface 152, so that frictional heat (polishing heat) is generated on the polishing surface 152. Also, heat is generated from the motors and bearings that constitute the power system and the drive system, and the heat is transmitted to the polishing surface 152 (hereinafter, referred to as “the polishing surface”).
These heats are collectively called frictional heat, etc.). Therefore, the surface plate 96, the polishing tool 52 (the substrate 138 and the abrasive layer) are formed based on the temperature difference between the polishing surface 152 where the frictional heat or the like is generated and the cooling water filled in the surface plate 54. 140)
, And the polished surface 152 is cooled.
At this time, the cooling water in the annular chamber 134 is
Flows from the outer peripheral side discharged from 28 toward the inner peripheral side while being exchanged with the polishing surface 152, and flows into the second inner peripheral side.
Since the gas passes through the annular groove 112 and is discharged from the through hole 126, the amount of heat exchange with the polishing surface 152 increases toward the inner peripheral side on the downstream side, and the temperature tends to increase. However, the cooling water in the annular chamber 134 whose temperature tends to increase toward the inner peripheral side due to the heat exchange with the polishing surface 152 is the cooling water provided in the annular chamber 134. Heat is exchanged also with the cooling water in the conduit 128 based on their temperature difference. Therefore, the cooling water in the cooling water conduit 128 is spirally circulated in the annular chamber 134 while exchanging heat with the cooling water in the annular chamber 134 toward the outer peripheral side toward the outer peripheral side. The temperature on the outer peripheral side where the cooling water temperature in the annular chamber 134 is lower tends to increase. Therefore, the tendency of the temperature of the cooling water in the annular chamber 134 to rise is offset by the tendency of the temperature of the cooling water in the cooling water conduit 128 in the opposite direction to increase. Since it is substantially uniform in the radial direction, the amount of heat exchange between the cooling water and the polishing surface 152 is maintained substantially uniform in the radial direction, and the temperature of the polishing surface 152 is uniform and constant in the radial direction. It will be kept at the temperature.

Further, since the cooling water in the cooling water conduit 128 flows in the circumferential direction while exchanging heat with the cooling water in the annular chamber 134, a temperature gradient may also occur in the circumferential direction. However, since the cooling water conduits 128 are spirally provided in multiple layers from the inner peripheral side to the outer peripheral side, 1
The temperature gradient is compensated for by the mutually adjacent portions of the cooling water conduit 128, such as the second and third rounds and the second and third rounds. In addition, since the annular chamber 134 is formed as a single chamber that is continuous in the circumferential direction, the generation of a temperature gradient in the circumferential direction is also suppressed by the movement of the cooling water flowing inside the annular chamber 134. Therefore, a large temperature gradient is not formed in the circumferential direction. Further, in this embodiment, two cooling water conduits 128a, 128b are provided such that their inner peripheral ends 130 start at circumferential positions different from each other by 180 degrees and are alternately located in the radial direction. Therefore, since the temperature rising tendency of the cooling water flowing therethrough differs by a half cycle, the heat exchange amounts with the cooling water in the annular chamber 134 are complemented by each other, and the annular chamber 134
The temperature distribution of the cooling water inside becomes more uniform in the circumferential direction. Therefore, since the temperature of the cooling water in the annular chamber 134 is uniform in both the radial direction and the circumferential direction,
A uniform temperature distribution is obtained in the surface of the surface plate 54 and in the polished surface 152, and the processing accuracy of the object 156 to be polished is enhanced. For example, with the structure of the present embodiment,
If it is less than about m), an extremely small temperature distribution of about ± 0.5 (° C) can be obtained.

As is apparent from the dimensions of the above-described parts and FIG. 7, the polishing surface 152 of the polishing tool 52 is provided in a range from the inner peripheral surface 114 of the first annular groove 110 to the inner peripheral side. Therefore, the cooling effect of the cooling water in the annular chamber 134 cannot be obtained in a portion on the inner peripheral side of the inner peripheral surface 114. However, a second annular groove 112 is provided in the inner peripheral portion in a range further from the inner peripheral end of the polishing surface 152 to the inner peripheral side.
The cooling water discharged through the second annular groove 112 is stored in an annular chamber formed between the second annular groove 112 and the surface plate 96, and is sequentially discharged from the recess 124 and the through hole 126. The inner peripheral portion of the polishing surface 152 is sufficiently cooled by the cooling water in the process. Therefore, the polishing surface 1
Sufficient cooling effect is given to the whole 52, and a substantially uniform temperature distribution can be obtained in the inner peripheral portion as well as in the outer peripheral portion.

In short, in this embodiment, the platen 54
Is provided continuously in the circumferential direction in an annular shape inside the
An annular chamber 134 for storing cooling water for maintaining the temperature of the fuel cell 52 at a predetermined temperature based on heat conduction;
A pair of cooling water conduits 128a, 128b, which are arranged spirally continuously in the circumferential direction and supply cooling water from the outer peripheral end opening 132 into the annular chamber 134;
The opening 13 of the cooling water conduit 128 in the annular chamber 134
2 is provided on the opposite side in the radial direction, and the annular chamber 134
Notch 1 for discharging cooling water inside the rotary platen 54
The cooling structure of the rotary platen 54 is configured to include the cooling plate 18.

Therefore, the cooling structure of the platen 54 is
4 has a simple structure in which an annular chamber 134 is provided and a spiral cooling water conduit 128 is provided therein.
Then, the polishing surface 1 of the polishing tool 52 fixed to the surface plate 54
The heat exchange is performed between the cooling water stored in the annular chamber 134 and the cooling water stored in the annular chamber 134.
4, heat is exchanged with the cooling water flowing in the cooling water conduit 128 spirally disposed in the cooling water conduit 4, and is replaced by the cooling water supplied from the opening 132 of the cooling water conduit 128 to form the cutout. It is sequentially discharged from 118. At this time,
Since the cooling water conduit 128 is helically disposed in the annular chamber 134, the cooling water in the annular chamber 134 is substantially uniform in the circumferential direction with the cooling water in the cooling water conduit 128. The annular chamber 134 is formed continuously in the circumferential direction, and a temperature gradient in the circumferential direction is difficult to be formed. Therefore, the temperature of the cooling water in the annular chamber 134 is substantially uniform in the circumferential direction. Will be maintained. Also, the opening 1 of the cooling water conduit 128
32 and the notch 118 are provided on the opposite side in the radial direction, so that the cooling water supplied from the opening 132 into the annular chamber 134 is moved in the radial direction until the cooling water is discharged from the notch 118. Temperature gradient generated by heat exchange with the polishing surface 152 in the process of cooling, and the cooling water in the cooling water conduit 128 is spirally moved and supplied while the cooling water is supplied from the opening 132 into the annular chamber 134. Since the temperature gradient tendency caused by heat exchange with the cooling water in the annular chamber 134 is opposite to the temperature gradient tendency, the temperature gradient tendency therebetween is canceled, and the cooling water in the annular chamber 134 is canceled. The temperature is maintained substantially uniform in the radial direction. Further, since the annular chamber 134 is not divided in the circumferential direction, the flow cross-sectional area of the cooling water, that is, the inner diameter of the cooling water conduit 128, the inner diameter of the opening 132, and the cross-sectional area of the notch 118 can be formed sufficiently large, and the supply / discharge path can be formed. Is hardly clogged, so that a high cooling effect can be obtained over a long period of time. Therefore, the annular chamber 1 has a simple structure.
34, the temperature of the cooling water in the polishing surface 152 is maintained substantially uniform over the entire surface, and the temperature of the polishing surface 152 is uniform over a long period of time.
The cooling structure of the surface plate 54 capable of obtaining the temperature distribution of

According to the present embodiment, the cooling water conduit 12
Numeral 8 is provided so that portions adjacent to each other in the radial direction are substantially in close contact with each other over substantially the entire radial width of the annular chamber 134. Therefore, since the gap between the cooling water conduits 128 is sufficiently small, the contact area between the cooling water in the annular chamber 134 and the cooling water in the cooling water conduit 128 is sufficiently increased,
Since the amount of heat exchange between them is sufficiently increased, the temperature distribution in the annular chamber 134 can be made more uniform.

In the present embodiment, the cooling water conduit 1
The opening 132 is provided at an outer peripheral position of the annular chamber 134, and the cutout portion 118 functioning as a discharge port is provided at an inner peripheral position of the annular chamber 134.
Therefore, while the cooling water is supplied to the outer peripheral position of the annular chamber 134 by the cooling water conduit 128, the cooling water is discharged from the inner peripheral position, and as shown in FIG. Notch 1
18, the second annular groove 112, the depression 124, and the through-hole 126 can be formed into a simple structure, and the manufacture of the surface plate 54 having the cooling structure is further facilitated.

In this embodiment, the cooling water conduit 1
28 are provided in the annular chamber 134. Therefore, since the position of the opening 132 for supplying the cooling water into the annular chamber 134 is set at a position opposite to the two cooling water conduits 128a and 128b in the circumferential direction, the balance of the surface plate 54 is maintained. It is easy to secure. Moreover, even if one of the two cooling water conduits 128 is closed or the flow resistance of the cooling water increases, the other cooling water conduit 128 supplies the cooling water into the annular chamber 134, and The heat exchange with the cooling water in the annular chamber 134 is performed substantially uniformly over the entire surface. Therefore, stable cooling can be performed for a longer time. Further, since the cooling water conduits 128a and 128b are provided so as to draw spirals different from each other by a half period in the circumferential direction, the temperature gradients in the respective circumferential directions are compensated for each other, so that a more uniform temperature distribution in the circumferential direction. Can be obtained.

While the embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be embodied in still another embodiment.

For example, in the embodiment, the case where cooling water is used as the heat medium has been described. However, other liquids such as a polishing liquid cooled to an appropriate temperature may be used or cooled. The present invention is similarly applied to a case where heating or heat is maintained by using a heat medium maintained at an appropriate temperature.

In the embodiment, the cooling water conduit 12
Although two 8s are provided in the annular chamber 134, the number thereof may be changed as appropriate and may be one or three or more. However, in order to increase the balance during rotation of the surface plate 54 as much as possible, and to make the temperature distribution in the circumferential direction as uniform as possible, it is desirable to provide at least two or more.

In the embodiment, the cooling water conduit 12
8 is formed in a spiral shape to allow the cooling water to flow from the inner peripheral side to the outer peripheral side. Conversely, it is connected to the receiving hole 104 formed in the base plate 54 on the outer peripheral side, and the inner peripheral side is opened. 132 may be located.

In the embodiment, the abrasive tool 52 of the fixed abrasive type having the abrasive layer 140 on the surface plate 54 is fixed and used. However, free abrasive grains are used. The polishing tool may be fixed and used. Also,
The present invention is similarly applied to a case where the polishing tool is constituted by the surface plate 54 itself and the object 156 to be polished is processed on the surface of the surface plate 96. That is, even if the polishing surface 152 is provided integrally with the surface plate 54, it is provided on the surface of the polishing tool 52 which is formed separately and fixed to the surface plate 54. It may be something.

In the embodiment, the first annular groove 11
0 is provided with a circumferential projection 116 and a second annular groove 112, and the cooling water conduit 1 is provided only in the first annular groove 110.
Although 28 is provided, the first annular groove 110 and the second annular groove 112 may be formed in one annular groove without providing the circumferential protrusion 116, and the cooling water conduit 128 may be provided as a whole. Further, even when the circumferential protrusion 116 is provided, the cooling water conduit 128 is provided in the second annular groove 112,
Cooling water conduit 128 and circumferential projection 11 in first annular groove 110
6, or may be connected separately to the water supply path. In this case, the first annular groove 1
The cooling water stored in the first annular groove 11 can be discharged through the second annular groove 112 similarly to the embodiment.
There is no need to separately provide a discharge path from zero.

The width of the first annular groove 110 in the radial direction is appropriately changed according to the diameter of the polishing surface 152, the rigidity of the platen 54, and the like. That is, in order to maintain the temperature distribution of the polishing surface 152 more uniformly, it is desirable that the first annular groove 110 and the cooling water conduit 128 be provided on the entire rear surface side of the polishing surface 152. When the rigidity of the platen 96 is sufficiently high, the first annular groove 110 may be formed to a position on the inner peripheral side as shown in the embodiment, and the polished surface 152 may be formed as compared with the case shown in the embodiment. If it is provided only on a part of the outer circumference that is sufficiently small, the inner circumference 1
The first annular groove 110 may be formed with a smaller width so that 14 is located on the outer peripheral side as shown in the embodiment. Also,
The groove depth and the like are also appropriately changed according to the amount of cooling water that is desirably stored.

In the embodiment, the cooling water conduit 12
8 was formed four times, but the number of windings and cooling water conduit 12
The size and the like of 8 are appropriately changed according to the size and purpose of the surface plate 54 and the like. Further, the cooling water conduit 128 is not provided substantially in close contact as shown in the embodiment, and may be provided at an appropriate interval.

Although not specifically exemplified, the present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a view illustrating an example of a conventional cooling structure of a surface plate.

FIG. 2 is a diagram illustrating another example of a conventional cooling structure for a surface plate.

FIG. 3 is a view for explaining still another example of the conventional cooling structure for a surface plate.

FIG. 4 is a view for explaining still another example of the conventional cooling structure for a surface plate.

FIG. 5 is a diagram illustrating still another example of the conventional cooling structure for a surface plate.

FIG. 6 is a perspective view showing an entire structure of a polishing machine to which a surface plate having a cooling structure according to an embodiment of the present invention is applied.

FIG. 7 is a view showing a cross section of a main part of the polishing machine of FIG. 6;

FIG. 8 is a diagram illustrating an internal structure of a surface plate used in the polishing machine of FIG. 6;

[Explanation of symbols]

 54: rotary platen 118: notch (discharge port) 128: cooling water conduit (heat medium conduit) 132: opening 134: annular chamber (heat medium storage chamber) 152: polishing surface 156: polished object

Claims (4)

[Claims] 1. A rotary platen for processing an object to be polished which is formed into a disk shape with a flat polishing surface on one surface and which is slidably contacted with the polishing surface by being rotationally driven around an axis. A temperature holding structure for holding a polished surface at a predetermined temperature, wherein the polished surface is provided in a continuous annular shape with a predetermined radial width in a circumferential direction inside the rotary platen, and the polished surface is used for heat conduction. A liquid-tight heat medium storage chamber for storing a heat medium for maintaining the heat medium at a predetermined temperature based on the heat medium storage chamber; the heat medium storage chamber is spirally disposed continuously in the circumferential direction in the heat medium storage chamber; A heat medium conduit for supplying a heat medium into the heat medium storage chamber, and an opening of the heat medium conduit in the heat medium storage chamber is provided on a side opposite to a radial direction, and the heat medium in the heat medium storage chamber is And a discharge port for discharging to outside of the turntable. Rotating platen temperature holding structure. 2. The rotary platen according to claim 1, wherein the heat medium conduit is provided such that portions that are radially adjacent to each other over substantially the entire width of the heat medium storage chamber are substantially in close contact with each other. Temperature holding structure. 3. An opening of the heat medium conduit is provided at an outer peripheral position of the heat medium storage chamber, and the discharge port is provided at an inner peripheral position of the heat medium storage chamber. 1
Temperature holding structure of rotary platen. 4. The temperature holding structure for a rotary platen according to claim 1, wherein a plurality of said heat medium conduits are provided in said heat medium storage chamber.