KR20190081328A - Method for setting the rotation center of wafer table - Google Patents

Abstract

The present invention relates to a method for setting the rotational center of a wafer table, to set the rotational center of a mounting unit having a wafer mounted thereon. According to the present invention, the method for setting the rotational center of a wafer table comprises: a setting step (S1) of setting an arbitrary point on a wafer ting (10) as temporary center coordinates (Oi); a displacement value measurement step (S2); a deviation calculation step (S3); and a center determination step (S4) of determining rotational central coordinates (Of) of a mounting unit (110).

Description

[0001] The present invention relates to a method of setting a rotation center of a wafer table,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device handler, and more particularly, to a method of setting a rotational center of a wafer table for setting a rotational center of a mounting portion on which a wafer is placed.

The term wafer refers to a process in which a semiconductor process such as deposition or etching is performed for the production of semiconductors and then separated into individual devices.

Specifically, the wafers are typically loaded on a tape & reel, or attached to a seating member such as a blue tape, for discrete individual elements on the wafer to be carried by the device handler for subsequent processing, shipping, and the like.

Here, each of the elements is attached on a so-called wafer ring having a blue tape to which a wafer in a state of being separated into discrete elements after being subjected to a semiconductor process or the like, as shown in Figs. 1 and 2, is attached.

It is generally unloaded by a device handler.

At this time, the element handler must accurately measure elements on the wafer ring in order to accurately pick up the elements on the wafer ring, and moves the wafer ring to the pickup position in the XY-θ direction using the XY-θ table It is common to pick up an element by a post-transfer tool and move the element to a predetermined position.

On the other hand, the size of the wafer ring is increased for mass production, and the size of the device to be manufactured is miniaturized, and a precise X-Y-? Of the wafer ring seated on the X-Y-? Table is required.

However, in the conventional device handler, there is a problem that an error in the manufacturing process and an error due to the decrease in durability due to use occur in the movement of X-Y- &thetas;.

Particularly, the conventional device handler has a problem that it is very difficult to correct the error of? As compared with X-Y.

Therefore, conventionally, there has been a need to correct the rotation center of the XY-theta table. Conventionally, the camera recognizes a ball or a line formed on the surface of the wafer to derive the center line of the wafer, , And aligning the wafers by designating notch points.

However, in the conventional method, there is a problem that the process efficiency is lowered by repeatedly performing the process of aligning the center of rotation of the wafer each time the wafer is placed on the XY-θ table, There is a problem that a recognition error occurs and alignment is impossible.

(Patent Document 1) KR10-1478249 B1

(Patent Document 2) KR1020150183247 A

(Patent Document 3) KR1020170002592 A

(Patent Document 4) KR1020170069687 A

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of setting a rotation center of a wafer table, which can simplify the above problems and effectively improve the operation performance of a device handler by effectively setting the center of rotation of the wafer table.

In order to achieve the above object, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an XY- Wherein at least one arbitrary point on the outside of the wafer ring seated on the seating part is defined as a set coordinate M _i , , the setting step (S1) of setting a temporary center coordinate (O _i) for any point on the wafer ring 10, and; The seating unit 110, the θ as the rotation by measuring the set coordinate value of the displacement measuring step of measuring a measurement XY displacement value (d ₁₎ in accordance with the movement of (M _i) (S2), and; The displacement measuring step (S2) the measured XY displacement value (d ₁₎ and measured at, assuming as the center of rotation the temporary center coordinate (O _i) of the set coordinates (M _i) which is calculated according to θ rotation A deviation calculating step (S3) of calculating a deviation (? _I ) between the calculated XY moving displacement value (d ₂ ); (O _f ) of the seat portion 110 by reflecting the deviation (? _I ) calculated in the deviation calculation step (S3) from the temporary center coordinate (O _i ) S4) of the center of rotation of the wafer table.

The setting step S1 may be performed in a state of being seated on the seating part 110.

The setting step (S1) is the set coordinates (M _i) performed by the n pieces, and the deviation calculating step (S3), the deviation (Δ _n) for all the n set coordinates (M _i) An average of the calculated deviations? _N after calculation can be determined as a deviation? _I for performing the central determination step S4.

Wherein the setting step S1 is performed by setting the set coordinates M _i to n and the displacement value measuring step S2 to the center determining step S4 are performed using the n set coordinates M _i , is corresponding to n times, and perform a sequential, it may be determined by following the provisional center of the coordinate (O _i), the rotation center coordinate determined in the previous center determining step (S4) (O _f).

The method of setting the center of rotation of the wafer table according to the present invention is advantageous in that the center of rotation of the wafer table can be precisely obtained by performing the method by a relatively simple method compared with the conventional method.

In particular, the method of setting the center of rotation of the wafer table according to the present invention is advantageous in that it can be performed more efficiently than the conventional method of repeatedly performing each time the wafer ring is loaded by first setting the center of rotation once.

According to another aspect of the present invention, there is provided a method of setting a wafer table rotation center, comprising: setting arbitrary set coordinates and a temporary rotation center outside a region occupied by a wafer ring; rotating a seat portion on which a wafer ring is seated by a preset angle; There is an advantage that the center of rotation of the seat portion can be more accurately set by correcting the center of gravity of the temporary assembly based on the calculation.

1 is a plan view showing an example of a device handler to which a wafer table rotation center setting method according to the present invention is applied.
Fig. 2 is a conceptual view of the element handler of Fig. 1 viewed from the side. Fig.
3 is an example of a wafer ring supplied to the wafer table of the element handler of Fig.
Figs. 4A and 4B show an example of a wafer ring supplied to the wafer table of the element handler of Fig. 1, wherein Fig. 4A is a perspective view showing a wafer ring and Fig. 4B is a sectional view showing a section of the wafer ring.
Fig. 5 is a plan view showing an example of a wafer table of the element handler of Fig. 1; Fig.
6 is a side view of the wafer table of Fig.
7A and 7B are plan views showing a process of setting the center of rotation of the seating portion of the wafer table of FIG.
FIG. 8 is a flowchart showing a method of setting a wafer table rotation center according to the present invention.

Hereinafter, a method of setting a wafer table rotation center according to the present invention will be described in detail with reference to the accompanying drawings.

The wafer table rotation center setting method according to the present invention includes a seating part 110 to which the wafer ring 10 is seated and fixed and a seating part moving part 120 for driving the XY-θ movement of the seating part 110 A method for setting the center of rotation of the rotation of the seating part 110 by the seating part moving part 120 in a wafer table 100 is described.

Particularly, in the method of setting the center of rotation of the wafer table according to the present invention, all of the device handlers including the wafer table 100 including the seating part 110 and the seating part moving part 120 as well as the patent documents 1 to 4 can be applied Do.

1 and 2, a plurality of wafer rings 10 to which a plurality of devices 1 are attached are mounted on a wafer (wafer) A loading section including at least one wafer table 100 that receives the wafer ring 10 from the ring cassette section 710 and horizontally moves the wafer ring 10; One that moves horizontally from the wafer table 100 and horizontally moves the element stacking member 20 to transfer the element 1 from the wafer ring 10 by one or more transporting tools 400, And an unloading unit including the wafer table 200 described above.

The loading unit is configured to move the wafer ring 10 in the horizontal direction by receiving the wafer ring 10 from the wafer ring cassette unit 710 loaded with the plurality of wafer rings 10 to which the plurality of devices 1 are attached Various configurations are possible as a configuration including one or more wafer tables 100. FIG.

The wafer ring cassette unit 710 can be configured in various configurations as a configuration in which a plurality of wafer rings 10 to which a plurality of devices 1 are attached are stacked.

Here, it is a device that has completed a semiconductor process and sowing process such as a semiconductor device, an LED device, and a solar cell device mounted on the wafer ring 10.

Particularly, the device 1 can be a wafer-level device that has completed a semiconductor process and a packaging process, as well as a semiconductor process and a sowing process.

On the other hand, the wafer ring 10 can be variously configured as a member on which a plurality of elements 1 are mounted, such as a tray and a wafer ring, if the element 1 can be loaded.

3 and 4A and 4B, the wafer ring 10 is a structure in which a device 1 having completed a preceding process such as a semiconductor process and a sowing process is mounted, And a frame member 12 for fixing the tape 11 and the tape 11 to each other.

The tape 11 can be any member as long as the elements 1 can be attached thereto, and a so-called blue tape can be used.

The frame member 12 can have various configurations such as a square ring, a circular ring (wafer ring), and the like for fixing the tape 11 to which the elements 1 are attached.

The wafer ring cassette portion 710 can be configured as long as the wafer rings 10 can be stacked up and down as a configuration for loading a plurality of wafer rings 10. [

The wafer table 100 receives the wafer ring 10 from the wafer ring cassette 710 and holds the wafer ring 10 horizontally so as to pick up the element 1 by the transfer tool 400, So that various configurations are possible.

Particularly, the wafer table 100 receives the wafer ring 10 from the wafer ring cassette unit 710 by means of a wafer ring loading unit (not shown) so that the transfer tool 400 can pick up the device 1 Various arrangements such as an XY table, particularly an XY-θ table capable of rotating θ, are possible as a configuration for moving the wafer ring 10 in the horizontal direction.

More specifically, the wafer table 100 is configured to move the wafer ring 10 in the XY-θ direction so that the element 1 on the wafer ring 10 is positioned at the pick-up position to pick up the element 1 of the transfer tool 400 Movement.

1, 5, and 6, the wafer table 100 includes a seating portion 110 to which the wafer ring 10 is seated and fixed, a holding portion 110 that holds the seating portion 110 in XY- and a seat moving portion 120 for driving the? movement.

The seating part 110 is configured to be fixed after the wafer ring 10 is seated, and various configurations are possible according to the loading and fixing method of the wafer ring 10. [

The seating part moving part 120 is configured to drive the seating part 110 to move in the X-Y- &thetas; and may have various configurations according to the driving method of the seating part 110. [

For example, the seating part moving part 120 includes a? -Rotating part 121 for driving rotation of the seating part 110 with the Z axis as a rotation axis, i.e.? Rotation, in a state of supporting the seating part 110, an X axis linear movement section 122 for linearly moving the rotation section 121 in the X axis direction and a Y axis linear movement section 123 for linearly moving the X axis linear movement section 122 in the Y axis direction .

The? -Rotating portion 121 is configured to drive the rotation of the seat portion 110 with the Z-axis as a rotation axis, that is,? Rotation in a state of supporting the seat portion 110, Various configurations are possible depending on the rotation structure.

The X-axis linear moving part 122 can be variously configured as a configuration for linearly moving the? -Rotating part 121 in the X-axis direction.

For example, the X-axis linear moving part 122 includes a first body provided with a guide member for guiding a linear movement of the movable member provided with the? -Rotating portion 121 in the X-axis direction, And a first linear driving unit for driving linear movement in the X-axis direction.

The Y-axis linear motion unit 123 can be variously configured as a configuration for linearly moving the X-axis linear motion unit 122 in the Y-axis direction.

For example, the Y-axis linear motion unit 123 may include a second body provided with a guide member for guiding linear movement of the first body in the Y-axis direction, and a second body including a Y- And a second linear driving unit.

On the other hand, at the time of element pickup by the picker 410 of the transfer tool 400 located at the element pickup position at a position corresponding to the lower middle element pickup position in the wafer ring 10 horizontally moved by the wafer table 100, A needle pin 190 for pushing up the image forming apparatus 1 upward can be provided.

The wafer ring loading section for transferring the wafer ring 10 from the wafer ring cassette section 710 to the wafer table 100 draws the wafer ring 10 from the wafer ring cassette section 710, Any configuration is possible as long as it can transmit the wafer 10 to the wafer table 100.

At this time, in order to smoothly exchange the wafer ring 10 having completed element pickup between the wafer table 100 and the wafer ring cassette unit 710 and the wafer ring 10 to be subjected to element pickup, A wafer ring buffer unit 810 in which the wafer 10 is temporarily stored can be provided.

The wafer ring buffer unit 810 includes a wafer ring 10 configured to be installed for smoothly performing the wafer ring 10 between the wafer table 100 and the wafer ring cassette 710 by the wafer ring loading unit The wafer ring 10 may be transferred to the wafer ring cassette 710 after temporary storage, and may be positioned at various positions in various configurations depending on the moving structure.

The transfer tool 400 may be configured to transfer the element 1 from the wafer table 100 of the loading part to the unloading part, and may have various configurations according to the pickup and moving structure of the element 1. [

In one example, the transport tool 400 includes a plurality of pickers 410 sequentially positioned at an element pick-up position and an element unloading position, and a plurality of pickers 410 along a circumferential direction And a rotation driving unit 430 for rotating the rotary arm 420 such that each of the plurality of pickers 410 is sequentially positioned at the element pickup position and the element unloading position.

The picker 410 is configured to be coupled to the rotary arm 420 to pick up the element 1, and various configurations are possible.

For example, the picker 410 has a structure similar to that of the pickup unit disclosed in Patent Document 4, and includes a main body coupled to the rotary arm 420, a pickup member coupled to the main body movably up and down, A rotation preventing portion for transmitting the air pressure to the pick-up member and preventing the rotation of the pick-up member, and a vertical drive portion for driving up and down movement of the pick-up member.

1 and 2, the picker 410 may be arranged such that the horizontal arrangement is at an angle difference of 90 degrees with respect to the rotation axis.

One or more image acquisition units 770 and 780 for measuring the pickup state of the element 1 picked up by the picker 410 during rotation of the picker 410 and the rotational position of the picker 410 are installed .

The image obtaining units 770 and 780 detect the picked-up state of the element 1 picked up by the picker 410 during rotation and the rotational position of the picker 410, And a camera for acquiring an image from the bottom side of the display unit 410, as shown in FIG.

Here, the image obtained by the image acquisition units 770 and 780 can measure the pick-up state of the element 1 picked up according to the image analysis, the rotational position of the picker 410, and the like.

For example, the image of the element 1 picked up by the picker 410 may be transmitted to the picker 410 for stable positioning on the unloading member 20 of the unloading portion, That is, the displacement in the X-axis direction, the displacement in the Y-axis direction, and the longitudinal direction of the picker 410 can be measured.

The image of the picker 410 obtained by the image acquiring units 770 and 780 is transmitted to the picker 410 rotated by the rotation driving unit 430 such as a motor to a predetermined design position, It is possible to measure the total rotation error about the rotation axis of the pickers 410. [

The unloading unit can be configured in various configurations as a structure in which the element loading member 20 is installed to be spaced from the wafer table 100 in the horizontal direction and to transfer the element 1 from the wafer ring 10

By way of example, the unloading section can be used for unloading the element 1, such as a wafer ring, such as a wafer ring, as shown in FIGS. 2, 3A, and 3B, a combination of a carrier tape and a cover tape The configuration of the element mounting member 20 can be determined according to the configuration of the element mounting member 20 for the element mounting member 20.

Meanwhile, the element mounting member 20 may have a configuration similar to that of FIGS. 3, 4A and 4B, and the unloading unit may have the same or similar configuration as the wafer table 10 of the loading unit described above.

More specifically, the unloading unit includes an element loading member 20 (hereinafter, referred to as an " unloading unit ") which is installed in the wafer table 100 in the horizontal direction and which receives the element 1 from the wafer ring 10 by one or more transfer tools 400 The wafer table 200 may include one or more wafer tables 200 that move the wafer table 200 in the horizontal direction.

That is, the unloading unit may have substantially the same configuration as that of the loading unit described with reference to FIGS. 1, 2, 5, and 6. FIG.

Here, the unloading unit may be disposed symmetrically with respect to the respective members and structures of the loading unit, and the bar member and the structure that are opposed to the loading unit with the transfer tool 400 as a center.

Meanwhile, the element mounting member 20 of the unloading portion corresponds to the wafer ring 10 of the loading portion, and the wafer table 200 of the unloading portion corresponds to the wafer table 100 of the loading portion and has the same or similar configuration Detailed explanations are omitted.

The element loading member 20 after the loading of the element 1 at the unloading portion can be transferred to the wafer ring cassette 720 positioned adjacent to the wafer ring table 200 by the member unloading portion .

The wafer ring cassette 720 is a structure in which the empty element mounting members 20 to be transferred to the wafer table 200 of the unloading portion to load the element 1 are loaded, The wafer is transferred to the wafer table 200 and can be reloaded after completion of device loading.

On the other hand, in the wafer table 100 of the loading section, the wafer table 200 of the pick-up and unloading section of the element 1 at the pick-up position is smoothly loaded on the wafer ring 10 Or the element mounting member 20 needs to be moved more precisely.

Particularly, as the size of the element 1 becomes smaller, the movement error of the wafer ring 10 or the element mounting member 20 acts as an obstacle to element pickup or device loading, resulting in malfunction of the apparatus, Process and so on.

In particular, when the element 1 is in the horizontal rotation state of the element 1 preset through the? Rotation of the wafer rings 100 and 200 when the element pickup or the element loading, for example, when the element 1 is rectangular, It is preferable that pickup or loading is performed.

Here, the correction of the horizontal rotation state of the element 1 is required to precisely set the rotation axis of the wafer rings 100 and 200 for image acquisition of the image acquisition units 770 and 780 located at the pickup position and the loading position, .

As shown in FIGS. 4A, 4B and 5, the present invention is characterized in that the wafer ring 10 includes a seating part 110 to which the wafer ring 10 is seated and fixed, a seat for moving the seating part 110 in the XY- The buoyant portion 120 is arranged on the wafer table 100 so that at least one arbitrary point outside the wafer ring 10 seated on the seating portion 110 is set on the wafer ring 10 at the set coordinates M _i setting for setting an arbitrary point of the temporary center coordinate (O _i) step (S1) and; A displacement value measuring step (S2) of measuring a measured XY displacement displacement value (d ₁ ) according to the movement of the set coordinate ( _Mi ) measured by rotating the seat part (110) by?; Calculating XY movement of the displacements measured the measured XY displacement value measured in the step (S2) (d ₁₎ and a temporary center coordinate (O _i) the set coordinates (M _i) is calculated based on the assumption about the rotational center in the θ rotation A deviation calculating step (S3) of calculating a deviation (? _I ) between the displacement values (d ₂ ); A central determination step of determining the rotation to the coordinates (O _f) (S4), the temporary center coordinate (O _i) the deviation of the receiving portions 110 is corrected to reflect the (Δ _i) calculated in the deviation calculating step (S3) from A wafer table rotation center setting method is provided.

The setting step S1 may set one or more arbitrary points outside the seating part 110 on the wafer table 100 including the seating part 110 to the set coordinates M _i .

For example, as shown in FIG. 7, the setting step S1 is a step of setting one or more arbitrary set coordinates outside the wafer ring 10 placed on the mount 110, for example, four set coordinates The accuracy of the rotation center coordinate O _f determined in the center determining step S4 described later can be increased by setting the coordinates M1, M2, M3, and M4.

On the other hand, it is needless to say that only one of the set coordinates M _i may be set, or a plurality of the set coordinates M _i may be set to two or more, or four or more.

The process of setting the set coordinates M _i may be performed by displaying an image of the seating unit 10 on a display for controlling the apparatus and controlling the operation of the seating unit 10 by a user's operation, The control unit is set outside the wafer ring 10 and the control unit is recognized as the set coordinate M _i in accordance with the user's setting.

The setting step (S1) is, on the wafer ring 10 can be set to the temporary center coordinate (O _i) for any point.

For example, as shown in FIG. 7, the setting step S1 is a step of setting the position of the wafer ring 100 at a position determined to be the center of rotation of the wafer table 100 by using the naked eye while viewing the image of the wafer ring 10 displayed on the display to be set to the temporary center coordinate (O _i), and can serve as a starting point for determining a rotational center coordinate (O _f).

The setting step S1 may change the order of setting the one or more set coordinates M _i and setting the temporary center coordinates O _i and may be set to the set coordinates M _i and the temporary center coordinates O _i ) can be arbitrarily set by the user.

The setting step S1 may be performed while the wafer ring 10 is seated on the seating part 110. [

The displacement value measuring step S2 is a step of measuring a measured XY displacement displacement value d ₁ in accordance with the movement of the set coordinate M _i measured by rotating the seat cushion 110 by? .

More specifically, the displacement value measuring step S2 moves the position of the set coordinate M _i corresponding to the rotation of the seating part 110 when the seating part 110 is rotated by? The XY moving displacement value (d ₁ ) can be measured.

Said deviation calculating step (S3), the measured measured in displacement measuring step (S2) XY displacement value (d ₁₎ and the set that is calculated in accordance with the θ rotation, assuming as the center of rotation the temporary center coordinate (O _i) The deviation? _I between the calculated XY movement displacement value d ₂ of the coordinates (M _i ) can be calculated.

At this time, the calculated XY movement displacement value d ₂ can be calculated as a displacement value of the set coordinate M _i calculated according to the rotation θ, assuming that the temporary center coordinate O _i is the actual rotation center.

Wherein the displacement value is set prior to the rotating coordinate (M _i), and a temporary center coordinate (O _i) the set coordinates (M _i) which is calculated according to θ rotation, assuming the actual center of rotation of the set coordinates (M _i) And is calculated as a deviation from the new coordinate.

The calculated XY displacement displacement value (d ₂ ) calculated according to the above method is compared with the measured XY displacement displacement value (d ₁ ) measured in the displacement measurement step (S2) to calculate the deviation (Δ _i ) Can be calculated.

At this time, the deviation? _I can be calculated by dividing by the X value deviation and the Y value deviation, respectively.

A rotation center coordinate (O _f) of the central decision step (S4), the temporary center coordinate (O _i) the deviation (Δ _i) to reflect the correction to the receiving portions (110) by calculating from the deviation calculating step (S3) from You can decide.

More specifically, the deviation (? _I ) calculated through the deviation calculation step (S3) can be corrected by reflecting the temporary center coordinate (O _i ), and the resultant value can be determined as the rotation center coordinate (O _f ).

On the other hand, it is difficult to accurately set the center of rotation of the wafer table by performing the above-described method of setting the center of rotation of the wafer table once. Embodiments of the method of setting the center of rotation of the wafer table by performing a plurality of times will be described.

As a first embodiment according to the present invention, the setting step S1 is performed with n sets of the set coordinates M _i , and the deviation calculating step S3 is performed with respect to all of the n set coordinates M _i deviation may be determined as a deviation (Δ _i) for the implementation of the central decision step (S4) the average of the deviation (Δ _n) calculated after calculating the (Δ _n).

More specifically, in the setting step S1, n (n is a natural number of 1 or more) set coordinates M _i and temporary center coordinates O _i are set.

Thereafter, the displacement value measurement step S2 may be performed for each of the set coordinates M ₁ , M ₂ , M ₃ , M _4, ..., and M _n .

That is, the measured XY moving displacement values d ₁ corresponding to the movement of each of the plurality of set coordinates are measured by rotating the seating part 110 by θ with respect to each set coordinate, and the set temporary center coordinates (O _i ) The computed XY displacement values d ₂ are computed such that each set coordinate is calculated corresponding to the rotation according to the result of rotation by θ.

Comparing the calculated XY displacement value (d ₂₎ corresponding to each rescued measured XY displacement value (d _1), for each set coordinate _{(M 1, M 2, M} 3, M 4 ... M n) The deviations (Δ ₁ , Δ ₂ , Δ ₃ , Δ ₄ ... Δ _n ) can be found and the average of each deviation can be calculated.

Then, the rotation center coordinates O _f can be obtained by correcting the average of the calculated deviations by reflecting the temporary center coordinates O _i .

In the second embodiment of the present invention, the setting step (S1) is performed with n number of setting coordinates ( _Mi ), and the displacement value measuring step (S2) and of set coordinate is corresponding to (M _i) performing an n-times successively, it is possible to determine the next temporary coordinates of the center of the (O _i), the rotation center coordinate (O _f) determined in the previous center determining step (S4).

More specifically, in the setting step S1, n set coordinates (M _i ) and temporary center coordinates (O _i ) are set.

Subsequently, for each set coordinate (M ₁ , M ₂ , M ₃ , M _4, ..., M _n ), for one set coordinate (M ₁ ) The rotational center coordinate O _f determined in the center determining step S4 may be sequentially set to the next set coordinates M ₂₎ it may be repeated by setting the temporary center coordinate (O _i) of, where the last set coordinates (M _n) in the displacement measuring step (S2), the deviation calculating step (S3) and the center determining step for (S4) The rotational center coordinate (O _f ) obtained as a result of the execution is set as the center of rotation of the wafer table.

On the other hand, with respect to the embodiment of the wafer table rotation center setting method according to the present invention, all of the θ values can be obtained, and the displacement value measuring step (S2), the deviation calculating step (S3) It is of course possible to carry out the decision step S4.

That is, a plurality of θ values of the displacement value measuring step (S2) and the deviation calculating step (S3) of the first embodiment are set and the displacement value measuring step (S2) and the deviation calculating step (S3) (M _i ), and the rotation center coordinates (O _f ) can be set using the average value of the deviations.

In the second embodiment, it is also possible to perform the displacement value measuring step S2, the deviation calculating step S3 and the center determining step S4 for a plurality of theta values according to the respective set coordinates M _i Of course.

Meanwhile, it is preferable that the step of setting the center of rotation of the wafer table according to the present invention is performed immediately after the assembly of the apparatus, immediately after the disassembly, and after the disassembly for maintenance, taking into account the error caused by assembly or the like.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It is to be understood that both the technical idea and the technical spirit of the invention are included in the scope of the present invention.

1: element 10: wafer ring
100: Wafer table

Claims (4)

A wafer table (100) having a seating part (110) in which a wafer ring (10) is seated and fixed and a seating part moving part (120) for driving XY -? Movement of the seating part (110)
One or more arbitrary points outside the wafer ring 10 seated in the seating part 110 are set as the set coordinates M _i and arbitrary points on the wafer ring 10 are set as the temporary center coordinates O _i , (S1);
By rotating the mounting part 110 as θ, a measured value of the set coordinates displacement measurement step of measuring a measurement XY displacement value (d ₁₎ in accordance with the movement of (M _i) (S2), and;
The displacement measuring step (S2) the measured XY displacement value (d ₁₎ and measured at, assuming as the center of rotation the temporary center coordinate (O _i) of the set coordinates (M _i) which is calculated according to θ rotation A deviation calculating step (S3) of calculating a deviation (? _I ) between the calculated XY moving displacement value (d ₂ );
Corrected to reflect a deviation (Δ _i) calculated by the deviation calculating step (S3) from the temporary central coordinates (O _i), central determination step of determining a rotation center coordinate (O _f) of the seating portion 110 (S4). ≪ / RTI > The method according to claim 1,
Wherein the setting step (S1) is performed in a state of being seated on the seating part (110). The method of claim 2,
The setting step (S1) is performed by setting the set coordinates ( _Mi ) to n,
It said deviation calculating step (S3) is performed for the n set coordinates (M _i) the deviation (Δ _n) of the deviation average of the central decision step (S4) of the (Δ _n) calculated after calculating the for both the Is set to a deviation (? _I ) for the wafer table rotation center. The method of claim 2,
The setting step (S1) is performed by setting the set coordinates ( _Mi ) to n,
The displacement value measuring step (S2) to the center determining step (S4) are sequentially performed n times corresponding to the n set coordinates ( _Mi )
Then the provisional center of the coordinate (O _i), the rotation center coordinate (O _f) of the wafer table and up the center of rotation, characterized in that determined in the previous center determining step (S4).

Images