KR20200083669A - Flatness measurement method and pin-height adjustment method - Google Patents

Abstract

[assignment]
It provides a practical technology that can easily measure the planar view of a face such as a virtual face formed by the top of a plurality of pins.
[Solution]
A measuring unit 4 having a flat top and bottom surface and having a level 6 attached to the measuring plate 5 of uniform thickness is placed on three adjacent pins 3 among the plurality of pins 3 In the state, the inclination of the measuring plate 5 in two orthogonal horizontal directions is measured by the level 6, and this step is sequentially performed for each of the three pins 3. In the second and subsequent steps, the inclination of the measuring plate 5 is selected for all the pins 3 while repeatedly selecting one of the pins 3 selected so far. From the inclination of the measuring plate 5, the difference in height between the pin 3 at the highest position at the top and the pin 3 at the lowest position at the top is calculated as a plan view.

Description

Flatness measurement method and pin height adjustment method {FLATNESS MEASUREMENT METHOD AND PIN-HEIGHT ADJUSTMENT METHOD}

The invention of this application relates to a technique for obtaining a planarity of a surface such as a virtual surface formed by the upper ends of a plurality of pins.

It is often required as a performance of a product that any surface is flat with high precision. In this case, any surface may be a virtual surface (virtual surface) or a surface of an actual member.

It is necessary, for example, in an apparatus for handling an object while holding the object using such a pin that the virtual surface formed by the top of the plurality of pins has a high planarity. To show a more specific example, in the manufacture of various electronic products and various display products, photolithography is performed to make a fine shape on the surface of the substrate. In photolithography, there is an exposure process in which light of a predetermined pattern is irradiated to the substrate while keeping the substrate horizontal. In the exposure process, a structure for holding the substrate by a plurality of pins in a vertical posture may be employed in response to requests such as making the contact area with the substrate as small as possible.

Japanese Patent Publication No. 2015-18927

In the exposure apparatus as described above, from the viewpoint of obtaining a high-precision exposure pattern, the substrate needs to maintain a horizontal attitude with high precision. This means that in the case of a structure in which the substrate is held by a plurality of pins, the virtual surfaces formed at the tops of those pins need to have a high-precision plan view.

However, from the research of the inventor, there is currently no practical technique that can easily measure the planar view of the virtual surface formed by the upper ends of the plurality of pins.

The invention of the present application has been made in consideration of this point, and an object of the present invention is to provide a practical technique capable of easily measuring a plan view of a surface such as a virtual surface formed by the top of a plurality of pins.

In order to solve the above problems, the invention described in claim 1 of this application already knows the arrangement in the horizontal direction and the tip of the plurality of pins forms a difference in the position in the height direction of the top of the plurality of pins extending vertically. A flatness measuring method for measuring as a planar view of a virtual surface,

It is a method of using a measuring unit having a flat upper and lower surfaces and having a uniform thickness and a level attached to the measuring plate.

Three-point measuring step of selecting three pins adjacent to each other among a plurality of pins, and measuring the inclination of the measuring plate in two orthogonal two horizontal directions with a measuring unit on the selected three pins. How to include,

It is a method to measure the top view by sequentially performing the three-point measuring step for each of the three pins.

The three-point measurement step after the second time is a step in which one of the selected pins up to that point is selected and measured.

It is a method to measure the inclination of the measuring plate by the level on all pins by sequentially performing the three-point measuring step.

Comprising the step of calculating the difference between the height of the pin at the highest position and the pin at the highest position from the slope of the two horizontal measuring plate in each three-point measurement step. Have

Moreover, in order to solve the said subject, the invention of Claim 2 is a flatness measuring method which measures the flatness in the horizontal direction of the upper surface of the object with a number of measurement point marks which already knows the arrangement|positioning in a horizontal direction,

A measuring unit having a flat top surface, a level attached to the measuring plate, and vertically extending downwardly from the bottom surface of the measuring plate, and a measuring unit having three leg pins of uniform length from the top surface of the measuring plate are used. How to do it,

The arrangement of the multiple measurement point marks is the same as the arrangement of the three leg pins of the measurement unit even when any three measurement point marks adjacent to each other are selected,

Among the multiple measurement point marks, three measurement point marks which are adjacent to each other are selected, and the leg pins of the measurement unit are raised on the three selected measurement point marks, respectively, and level the inclination of the measurement plate in two orthogonal horizontal directions. Method comprising a three-point measuring step to measure by,

It is a method of measuring a plan view by sequentially performing a three-point measuring step for each of the three measuring point marks,

The third-point measurement step after the second time is a step of repeatedly selecting one of the three measurement point marks selected so far and performing measurement,

It is a method to measure the inclination of the upper surface of the measuring plate by level using all the measuring point marks by sequentially performing the three-point measuring step.

And calculating the difference between the height of the measurement point mark at the highest position and the measurement point mark at the lowest position from the inclinations of the upper surfaces of the two horizontal measurement plates in each three-point measurement step. .

In addition, in order to solve the above problems, the invention described in claim 3 is provided with a base plate and a plurality of pins which are attached to the upper surface of the base plate and extend vertically upward, and the protrusion height of each pin is adjustable. In the unit, as a pin height adjustment method for adjusting the protruding height of each pin from the base panel,

A planarity measuring process for measuring a difference in position in the height direction of the upper end of the plurality of pins as a plan view of a virtual surface formed by the tip of the plurality of pins

In the flatness measurement process, there is an adjustment process for adjusting the protruding height of each pin according to the measurement result of the flatness,

The planarity measuring process is a process using a measuring unit having a flat upper surface and a lower surface and having a uniform thickness and a level attached to the measuring plate, and among the multiple pins, three adjacent pins are selected, It is a process including a three-point measuring step of measuring the inclination of the measuring plate in two orthogonal two horizontal directions with the measuring unit on the three selected pins, by a level,

The plan view measurement process is a process of measuring a plan view by sequentially performing a three-point measurement step for each of the three pins,

The three-point measurement step after the second time is a step of repeatedly selecting and measuring one of the three selected so far,

The planarity measurement process is a process of sequentially measuring the inclination of the measuring plate by a level on all pins by sequentially performing a three-point measurement step.

The plan view measuring process calculates a difference between the heights of the pins at the highest position and the pins at the lowest position at the top from the inclinations of the two horizontal measurement plates in each three-point measurement step. It contains,

The adjustment process has a structure called a method of adjusting the protruding height of each pin so as to reduce the difference in height measured in the flatness measurement process.

Moreover, in order to solve the said subject, the invention of Claim 4 WHEREIN: In the structure of Claim 3, the said adjustment process is a process which interposes a shim between the said base board and the said pin, and in the said flatness measurement process It has a configuration called the process of selecting the thickness of the shim according to the measurement result.

Moreover, in order to solve the said subject, the invention of Claim 5 WHEREIN: In the structure of Claim 3 or Claim 4, after performing the said adjustment process, the said planarity measurement process is performed again, and the difference in height of the upper end of each pin It is configured to judge whether it is within a certain range and, if not, to perform the adjustment step again.

As described below, according to the invention described in claim 1 of this application, it is possible to easily measure the plan view of the virtual surface formed by the upper ends of the plurality of pins. As for the tool used for measurement, since it is a simple combination of a level and a measuring plate, it can be realized at low cost. For this reason, it becomes an extremely practical measuring method.

Moreover, according to the invention described in claim 2, it is possible to easily measure the top view of the upper surface of the object. As for the tool used for measurement, it is a simple combination of a spirit level, a measuring plate, and a leg pin, so it can be realized at low cost. For this reason, it becomes an extremely practical measuring method.

In addition, according to the invention described in claim 3, the flatness is measured by repeating the measuring step using a measuring unit, and the pin height is adjusted based on this, so that the measurement result can be obtained and adjusted by a simple procedure. For this reason, even if measurement and adjustment are repeated, no effort is required and troublesome.

Moreover, according to the invention described in claim 4, in addition to the above effects, since a shim is used, it is possible to easily and reliably adjust the protruding height of each pin.

Moreover, according to the invention described in claim 5, in addition to the above effects, a method suitable for a case where a particularly high planarity is required is provided.

1 is a perspective schematic view of a pin unit in which the plan view measuring method of the first embodiment is implemented.
2 is a perspective schematic view of a measurement unit used in the method of the first embodiment.
3 is a schematic plan view showing a plan view measuring method of the first embodiment.
4 is a plan schematic view showing a plan view measuring method of the first embodiment.
Fig. 5 is a perspective schematic view showing the main parts of a calculation process for calculating a plan view from each measurement data in the plan view measurement method of the embodiment.
6 is a diagram schematically showing an example of execution of the calculation processing step by the table calculation software.
7 is a front schematic view showing a pin height adjustment method according to an embodiment.
8 is a perspective view schematically illustrating a plan view measuring method of a second embodiment.

Next, a form (hereinafter, embodiment) for carrying out the invention of this application will be described.

The invention of this application is a method of measuring the flatness of a certain surface, the embodiment of which is a method of measuring the flatness of a virtual surface formed by the upper ends of a plurality of vertically extending pins, and the upper surface of a certain member. It is largely distinguished by the method of measuring the flatness.

Hereinafter, as a first embodiment, a method of measuring a plan view of a virtual surface formed by the upper ends of a plurality of pins will be described. 1 is a perspective schematic view of a pin unit in which the plan view measuring method of the first embodiment is implemented.

The pin unit 1 to which the plan view measurement method of the embodiment is carried out includes a base plate 2 and a plurality of pins 3 attached to the upper surface of the base plate 2. As shown in Fig. 1, the plurality of pins 3 are vertically attached. The upper surface of the base plate 2 is a horizontal and flat surface with required precision. Each pin 3 is attached so that the protruding height from the upper surface of the base plate 2 becomes constant. For example, each pin 3 is of the same length, and is attached by a threaded insert. Thus, the top of each pin 3 will theoretically be located on the same imaginary horizontal plane. However, as a result of factors affecting each other, such as dimensional accuracy of each pin 3, attachment accuracy (insertion depth, etc.), and plane precision of the upper surface of the base plate 2, the top of each pin 3 is the same. It is less likely to be positioned at the required precision for the height position. That is, the virtual surface formed by the upper end of each pin 3 may not have the necessary plan view. The method of the embodiment is intended to detect this by measurement.

Moreover, as shown in FIG. 1, each pin 3 is arrange|positioned at the position on the scale of a checkerboard (on each intersection of a right angle grid). The intervals between the adjacent pins 3 are all the same.

2 is a perspective schematic view of the measurement unit 4 used in the method of the first embodiment. The measurement unit 4 shown in FIG. 2 includes a measurement plate 5 and a level 6 attached to the measurement plate 5.

Since the measuring plate 5 is located between each pin 3 and the level 6 to be measured, it has a required flatness. That is, the measuring plate 5 is a plate of a constant thickness having a sufficiently flat upper and lower surfaces. The material of the measuring plate 5 is not particularly limited, but is often a metal such as stainless steel or aluminum. As shown in Fig. 2, the measurement plate 5 has a chamfered right-angled isosceles triangle shape.

As the level 6, in this embodiment, a digital 2-axis level is used. That is, the level 6 is capable of measuring the inclination of the measuring plates 5 in two orthogonal horizontal directions.

In this embodiment, the level 6 is supposed to send data by wireless communication. The level 6 is equipped with a built-in transmitter 61 and a receiver 62 that receives measurement data transmitted from the transmitter 61. The receiving unit 62 functions as a remote controller that controls the level 6. The transmitting unit 61 and the receiving unit 62 are intended to perform wireless communication by appropriate standards such as specific low-power radio, infrared communication, and Bluetooth (registered trademark). As the level 6, for example, SEL-121BM manufactured by Sakamoto Electric Co., Ltd. can be used.

Moreover, the measurement unit 4 is used together with the calculation processing unit 7 which performs calculation processing for measurement of a plan view. Various configurations can be assumed as the calculation processing unit 7, but in this embodiment, a general-purpose computer such as a desktop PC is used. The receiver 62 of the level 6 and the general-purpose computer as the arithmetic processing unit 7 are connected via a cable 71 of a general-purpose interface such as USB. The arithmetic processing unit 7 is equipped with a program that processes measurement data output from the level 6 to calculate a plan view.

Next, a plan view measuring method using the measuring unit 4 will be described with reference to FIGS. 3 and 4. 3 and 4 are plan schematic views showing a plan view measuring method of the first embodiment.

In the plan view measuring method of the embodiment, three pins 3 adjacent to each other among a plurality of pins 3 are selected so that the inclination of the measuring plate 5 in two orthogonal horizontal directions can be measured, A method of sequentially performing a step (hereinafter referred to as a three-point measuring step) of measuring the inclination of the measuring plate 5 by the level 6 with the measuring unit 4 on the three selected pins 3 to be. The "sequentially performed" means sequentially performed on each of the three pins 3. The three-point measurement step after the second time is a step of performing a measurement of selecting (over) one of the three pins 3 selected so far.

3, the arrangement direction of each pin is set to the X direction and the Y direction. It is assumed that the number of pins is m in the X direction and n in the Y direction. In addition, for simplicity, the measurement direction of the level 6 (the direction of the two axes) is assumed to be the same in the X direction and the Y direction. Therefore, the base plate 2 is precisely arranged (positioned) so that the alignment direction of the pins in advance coincides with the measurement direction of the level 6.

In the arrangement of the pins shown in Fig. 3, in order to identify each pin, the lower left pin is set to P ₁₁ and the upper right pin is set to P _mn . And, the bottom row is P ₁₁ , P ₂₁ ,… Let P _m1 , and the column above it, P ₁₂ , P ₂₂ ,… Let P _m2 . In the same way, the top row is P _1n , P _2n ,… Let P _mn .

In the plan view measuring method of the embodiment, while the one pin 3 is repeatedly selected, the three adjacent pins 3 are sequentially selected to measure the inclination of the measuring plate 5. It is to be able to specify the selected three pins (3). As this method, it is also possible to implement it in software, but in this embodiment, the order of selecting the three pins 3 is determined, and the order is made not to be wrong.

To illustrate a more specific example, as shown in Fig. 3(1), in the first three-point measurement step, three lower-left pins, namely P ₁₁ , P ₂₁ , and P ₁₂ are selected to perform the three-point measurement step. . P ₁₁ , P ₁₂ , P ₂₁ are stretched over them to raise the measuring unit 4 and the level 6 is operated to measure the inclination of the measuring plate 5. The measurement data is the inclination of the measurement plate 5 in the XY direction, and this data is transmitted from the transmission unit 61 to the reception unit 62 and sent from the reception unit 62 to the arithmetic processing unit 7. With this, the first three-point measurement step ends.

Next, as shown in Fig. 3(2), three pins of adjacent jaws are selected to the right. That is, P ₂₁ , P ₃₁ and P ₂₂ are selected and the three-point measurement step is performed in the same manner. In this case, pin P ₂₁ overlaps with that in the three-point measurement step up to that point. Similarly, three pins P ₃₁ , P ₄₁ , and P ₃₂ of adjacent groups are selected to the right, and a three-point measurement step is performed. By repeating the same operation, if a three-point measuring step is performed on P _(m-1)1 , P _m1 , and P _(m-1)2 , the three-point measuring step on the pin 3 in the bottom row is ended. .

Next, a three-point measuring step is performed on the second row of pins from the bottom. That is, as shown in FIG. 4(1), the measurement unit 4 is moved upward as it is, and _three- step measurement steps are performed for P _(m-1)2 , _Pm2 , and P _(m-1)3 . In this case, P _(m-1)2 is a pin overlapping with that of the previous three-point measurement step.

Then, a three-point measurement step is performed on the three pins P _(m-2)2, P _{(m-1)2, and} P _(m-2)2 on the left side, and thereafter sequentially shifting to the left, 3 Do the point measurement step. Then, when the three-point measurement step is performed on the three leftmost pins P ₁₂ , P ₂₂ , and P ₁₃ , each three-point measurement step for the second row of pins ends.

Thereafter, the measurement unit 4 is moved upward in the unchanged posture, and a three-point measurement step is performed for the three pins P ₁₃ , P ₂₃ and P ₁₄ immediately above. Then, this time sequentially shifting to the right, a three-point measurement step is performed for each of the three pins.

In this way, as shown by the arrow in Fig. 4(2), the three-point measuring step is performed for each of the three pins by changing the direction each time the column changes (zigzag). Then, after performing the three-point measuring step to the end of the top row (the right end in this example), as shown in Fig. 4(3), the direction of the measuring plate 5 is changed by 180 degrees to perform the three-point measuring step. . This is to measure the pin at the end of the top row (pin P _{mn in} this example). This is the last three-point measurement step, and with this, the acquisition of the measurement data is entirely ended. In the last three-point measurement step, two pins, pin P _(m-1)n and pin Pm _(n-1) , overlap with respect to the three-point measurement step immediately before. Therefore, in the last three-point measurement step, two pins overlap with the previous three-point measurement step.

In this way, for all the pins, three points of measurement are performed while three adjacent pins are selected to obtain respective measurement data. Then, by performing an arithmetic processing step of applying a suitable arithmetic processing to the obtained measurement data, a desired plan view is obtained. Next, this point will be described.

Fig. 5 is a perspective schematic diagram showing the main parts of a calculation process for calculating a plan view from each measurement data in the plan view measurement method of the embodiment. In FIG. 5, processing of the measurement data obtained in the first three-point measurement step is shown.

In FIG. 5, the heights of the upper ends of the pins P ₁₁ , P ₂₁ , and P ₁₂ are H ₁₁ , H ₂₁ , and H ₁₂ . The height requires a horizontal surface as a reference, and can be, for example, an upper surface of the base plate 2. In Figure 5, the pin has a height H ₁₂ of the high P _12, P ₂₁ the pin, but the height of the low, this is an example of the measurement results.

Now, the pin relative to the height of the P ₁₁ H _11, and the amount of the difference in height is higher than that, a negative difference in height of lower than it. In this case, since pin P ₂₁ is on the same straight line in the X direction with respect to pin P ₁₁ and pin P ₁₂ is on the same straight line in the Y direction with respect to pin P ₁₁ , each difference is expressed by the following equations 1 and 2 Is displayed.

In the formula 1, dH is _1, the difference between H ₂₁ to H _11, H ₂₁ in dH ₂ is a difference for the ₁₁ H. θ _xi is the inclination angle in the X direction, θ _Y1 is the inclination angle in the Y direction, and is measured data in the corresponding three-point measurement step. w is a separation interval in the XY direction of each pin.

When the positive and negative of the tilt angle is described, in FIG. 5, the pin P ₁₁ is used as the origin, the X direction toward the right side on the paper plane of FIG. 3 is set to the + side, and the counterclockwise direction based on this is the tilt angle in the X direction. Let it be a positive angle in. Also in the Y direction, the pin P ₁₁ is used as the origin, and the Y direction directed toward the oblique upper side on the paper plane in FIG. 3 is set to the + side, and is set as a positive angle in the inclined angle in the counterclockwise Y direction based on this.

In this way, the difference in height H ₂₁ with respect to the height H ₁₁ and the difference in height H ₁₂ are respectively calculated.

Next, the measurement data of the three adjacent pins P ₂₁ , P ₃₁ , and P ₂₂ are examined. Also in this case, the difference of the height H ₃₁ with respect to the height H ₂₁ and the difference of the height H ₂₂ with respect to the height H ₂₁ are computed by Formula 3 and Formula 4, respectively.

In equations 3 and 4, dH ₃ is the difference of H ₃₁ to H ₂₁ , and dH ₄ is the difference of H ₂₂ to H ₂₁ . Similarly, θ _X2 is measurement data of the tilt angle in the X direction, and θ _Y2 is measurement data of the tilt angle in the Y direction. Substituting the results of Equation 1 and Equation 2 for Equations 3 and 4, the height H ₃₁ of the two pins P ₃₁ and P ₂₂ measured in the second three-point measurement step is increased to the height H ₁₁ of H ₂₂ . For the difference.

Thereafter, although the description is omitted, the difference in height H ₁₁ of the heights of the pins P ₄₁ and P ₃₂ is determined by the measurement data in the third three-point measurement step, and the measurement in the fourth three-point measurement step is obtained. The difference between the heights H ₁₁ of the heights of the pins P ₅₁ and P ₄₂ is obtained from the data.

In this way, by substituting and applying the calculation result to the measurement data in the next three-point measurement step, the difference of the height H ₁₁ of the pin P _{11 in} the lower left is obtained for all the pin heights.

Then, among all the pins, the pin with the highest position and the lowest pin can be specified, and the difference between the heights of the pins can be used to make the measurement result of the plan view.

In addition, in the processing of each measurement data, since the measurement data in the last three-point measurement step is measured by reversing the direction of the measurement unit 4, it is inclined by reversing positive and negative for each of the X and Y directions. Judging each positive and negative sound.

When a more specific example is explained with respect to the calculation processing step, the calculation as described above can be easily performed by using so-called surface calculation software. An example of this will be described with reference to FIG. 6. 6 is a diagram schematically showing an example of execution of the calculation processing step by the table calculation software.

In FIG. 6, the number of the three-point measurement step is input to one cell column A, and the inclination angle in the X direction is input from the measurement data of the corresponding three-point measurement step to the other cell column B, and to the other cell column C, The tilt angle in the Y direction is input.

In addition, the pin heights (strictly, the difference in height) calculated according to the measurement data in the three-point measurement step are input to other cell columns D to F. In Fig. 6, the pin located at the apex angle (angle of 90 degrees) in a right-angled isosceles triangle in each three-point measurement step is called a "triangular origin pin", and the height of the top of the pin is input to the cell column D. Moreover, the pin located in the X direction with respect to the triangular origin pin is called a "X direction pin", and the height of the upper end of the pin is input to the cell string E. In addition, the pin located in the Y direction with respect to the triangular origin pin is called a "Y direction pin", and the height of the top of the pin is input to the cell column F.

More specifically, in the example of FIG. 6, the height of the pin P ₁₁ (=0) is input to the cell D2, the height of the pin P ₂₁ is input to the cell E2, and the height of the pin P ₁₂ is input to the cell F2. . Cell E2 is a value calculated by applying the measurement data of cell B2 to Equation 1 (the result of the interpolation calculation), and cell F2 is a value calculated by applying the measurement data of cell C2 to Equation 2. In order to automatically perform this calculation, the calculation formulas are pre-entered in cells E2 and F2.

In the third cell row, measurement data in the second three-point measurement step is input and calculated. In this case, since the height of the pin P ₂₁ is input to the cell D3, the link of the cell is set so that the value of the cell E2 is copied for each calculation formula. The height of the pin P ₃₁ is input to the cell E3, and the height of the pin P ₂₂ is input to the cell F3. Cell E3 is a value calculated by applying the measurement data of cell B3 to Equation 1 (the result of the interpolation calculation), and cell F3 is a value calculated by applying the measurement data of cell C3 to Equation 2. In order for this calculation to be performed automatically, a link or a calculation expression is set in advance. 6 is an example in the case where the separation distance w of each pin 3 is 100 mm.

Hereinafter, although the description is omitted, the link or calculation formula is set in the same way for the cells in each row, and when measurement data is input to the cell columns B and C, the link or calculation of each cell in the cell columns D to F is updated. The difference in height of each pin is automatically calculated.

In addition, in the measurement data at the last three-point measurement step, the calculation of the height of the pin P _mn may be calculated based on the height of the pin P _m(n-1) , or the pin P _{(m-1) n} You may calculate based on the height of, and either one is previously set.

In the calculation processing using the table calculation software in this way, by setting the link or calculation formula appropriately for each cell, the height of the top of all the pins 3 is obtained based on the pin P ₁₁ in the lower left, The difference between the highest value and the lowest value is obtained as a plan view.

In addition, the measurement data is sent from the receiver of the level 6 to the operation processing unit 7 via USB. When the macro program is properly installed in the table calculation software so that the measurement data is sequentially input to the cell column B and the cell column C, Suitable. That is, upon receiving the measurement data, the inclination angle in the X direction is input to the active cell in the cell column B, the inclination angle in the Y direction is input to the active cell in the cell column C, and the cell column B and the cell column C in one row below are entered. A macro program that activates is installed.

According to the plan view measuring method of the above-described embodiment, the plan view of the virtual surface formed by the upper ends of the plurality of pins 3 can be easily measured. The tool used for the measurement is also a simple combination of the level 6 and the measurement plate 5, and thus can be realized at low cost. For this reason, it becomes an extremely practical measuring method.

In the plan view measuring method of the above-described embodiment, the procedure of selecting each of the three pins 3 may be other than those described above. After the measurement is performed on the lowest column, the measurement unit 4 may be sequentially moved in the same direction as the left end for the second column from the bottom. Therefore, the overlapped pin may not be the pin selected in the previous three-point measurement step. The important thing is not to be wrong about the measurement of the set of the three pins 3, and it is to select all the sets of the three pins 3 in a predetermined order and measure all the pins 3.

From the above point of view, it is possible to always select the two pins 3 repeatedly, but since it is easy to complicate the calculation, it is preferable to set the three-point measuring step with only one overlapping number as much as possible. . In addition, in the above example, there are a large number of pins 3 in which the height of the upper end is repeatedly calculated, but may be overwritten to calculate, or the initial calculation result may be maintained.

In the above description, the measurement unit 4 has been described to be picked up by an operator by hand and placed at each position, but may be automated with a robot or the like. For example, there may be a case where the position of the arrangement of the measurement unit 4 and its routine are taught by teaching the robot.

Moreover, about the measurement unit 4, although a biaxial level level is preferable, it can also be implemented by a single axis type. In the case of the uniaxial type, the level 6 is configured to change the 90 degree direction on the measuring plate 5. Then, for each of the three pins 3, two measurements are made with the level 6 changed by 90 degrees. In addition, the calculation processing unit 7 may have a structure in which the level 6 is built-in or is attached to the level 6, and the calculation processing unit 7 is not provided separately from the level 6 There may be cases. Moreover, the arithmetic processing unit 7 may be provided as part of a substrate processing apparatus such as an exposure apparatus.

As the shape of the measuring plate 5, other shapes, such as an L shape, are also conceivable besides a triangle. However, if a space for fixing the level 6 is required, and the level 6 is not fixed at the center position of the measurement plate 5, the rise of the measurement plate 5 (from the top of either pin 3) A triangle is preferable from things that are likely to fall off).

It is also possible to measure the four pins 3 in a state where the measuring unit 4 is raised, and theoretically, it is also possible to calculate the plan view, but the measuring plate 5 has four pins 3 It is difficult to keep all of the upper ends in contact with each other, but the calculation processing is complicated, so a structure in which the measurement unit 4 is placed on the three pins 3 is preferable.

In addition, in the above description, although the XY in the arrangement direction of the two axes in the level 6 and the pin 3 are coincident, measurement can be performed if the misalignment is already known even if they are not. According to the misalignment angle between the measurement direction in the level 6 and the arrangement direction of the pins 3, correction when viewed from a plane is performed, and then the above calculation processing may be applied. However, the calculation processing is simplified when the alignment directions of the two axes and the pins 3 in the level 6 coincide.

Next, an embodiment of the invention of the pin height adjustment method will be described. 7 is a front schematic diagram showing a pin height adjustment method according to an embodiment.

The pin height adjustment method of the embodiment uses the plan view measurement method of the above-described embodiment. That is, after measuring the plan view as described above, by adjusting the protruding height of each pin 3 according to the measurement result, the difference in the height of the top of each pin 3 is suppressed to within a certain range.

In this embodiment, a shim (precision spacer) 8 is used for adjustment of the protruding height of each pin 3. The shim 8 is, for example, an annular member, which is already known for its high thickness and precision. As described above, each pin 3 is fixed by a threaded insertion with respect to the base plate 2, wherein the thread cutting portion at the bottom of each pin 3 is thinner than the central opening of the shim 8, and thread cutting The trunk portion above the portion is smaller than the central opening of the shim 8. Therefore, each pin 3 can be screwed into the base plate 2 with the shim 8 inserted. By appropriately selecting the type (thickness) and the number of sheets of the shim 8, the protruding height of the pin 3 from the base plate 2 is adjusted.

In the pin height adjustment method of the embodiment, the above-described flatness measurement method is performed, and the difference in height at the top is measured based on the specific pin 3 (pin P _{11 in the} above example). Next, the difference is recalculated based on the pin 3 having the highest height. Since the differences are all negative values, the type and number of shims 8 are selected accordingly (so that the difference is zero). At this time, there are often no combinations of shims 8 that fit the difference, and in that case, the combination of the closest (approximate) shims 8 is selected.

For example, if the difference in height of a pin 3 is -69 μm, and there is a shim 8 having a thickness of 10 μm and a shim 8 having a thickness of 50 μm, two 10 μm shims 8 are stacked at 50 μm. A single shim 8 is prepared, and the pins 3 are screwed into the base plate 2 by overlaying them. In this way, the pins 3 are reinserted while the shims 8 of a different amount are inserted into all the other pins 3 so that the position of the upper end fits the highest pin 3.

In the method of the embodiment, after adjusting the height in this way, the plan view is measured once more. That is, the measurement unit 4 is sequentially placed on each of the three pins 3, and each three-point measurement step is performed. Then, the difference between the heights of the upper ends of the respective pins 3 is confirmed. In this case, if the difference in height falls within a certain range, adjustment is terminated with this, but in most cases, it does not fall within a certain range. The predetermined range is the required precision of the plan view, and relates to the extent to which the difference in height of the upper end of the pin 3 is allowed. Reasons not to fall within a certain range include errors in the initial measurement, influence by the selection of the approximate shim 8, slight deviation in the thickness of the shim 8, and deviation in the insertion depth when the thread is inserted after adjustment. to be. As they work together, as a result, there is often a deviation in the height of the top.

Anyway, if it is not within a certain range, it is adjusted again. In the adjustment again, it is preferable to remove or add the shim 8 to make the necessary minimum adjustment. That is, the average value of the height of the upper end of each pin 3 is calculated, and an adjustment amount of plus or minus is calculated on the basis of it. Then, if it is a positive adjustment amount, the type and number of the shims 8 closest to it are judged and added. If the adjustment amount is negative, the longest shim 8 of the kind closest thereto is removed.

Then, the flatness is measured once more, and if it is within a certain range, the adjustment is terminated. If not, remove the shim 8 and adjust it again, and repeat the measurement and adjustment until it enters a certain range. Normally, the adjustment is completed by measuring and subtracting about 2-3 times.

According to the pin height adjustment method of the embodiment, the flatness is measured by repeating the three-point measurement step using the measurement unit 4, and the pin height is adjusted based on this, so that measurement results can be obtained and adjusted by a simple procedure. Can. For this reason, even if measurement and adjustment are repeated, no effort is required and troublesome.

Moreover, since the shim 8 is used, it is possible to easily and surely adjust the protruding height of each pin 3. Alternatively, the insertion depth of each pin 3 may be adjusted.

Moreover, the method of the said embodiment which repeats a measurement and adjustment is employ|adopted suitably especially when a high planarity is calculated|required.

Next, a method of measuring a plan view of the second embodiment will be described. 8 is a perspective view showing an outline of a plan view measurement of the second embodiment.

The first embodiment was a method of measuring the planar view of the virtual surface formed by the upper ends of the plurality of pins 3, but the second embodiment was a method of measuring the planar view of the surface (real surface) of the object. . This method is suitably performed, for example, when measuring the planar view of the upper surface of a member that provides a horizontal surface that is a mechanical structural reference such as the base plate 2 described above.

The measurement unit 4 used in the second embodiment is slightly different from the first embodiment. That is, the measuring unit 4 used in this method, as shown in Fig. 8, the level 6 is fixed to the upper surface of the measuring plate 5, and the three leg pins from the lower surface of the measuring plate 5 ( 51) is configured to extend vertically downward.

At least the upper surface of the measuring plate 5 is a flat surface. Flatness is defined in relation to the accuracy of the flatness to be measured.

The measuring plate 5 is similarly triangular (here, a right angle isosceles triangle shape), and the level 6 is fixed to the center of the measuring plate 5. As the level 6, a digital wireless two-axis level is suitably used.

It is necessary that the three leg pins 51 extending downward have a uniform length from at least the upper surface of the measuring plate 5. Typically, it is achieved by making the lower surface of the measuring plate 5 the same as the upper surface, making the thickness of the measuring plate 5 uniform, and making the lengths of the leg pins 51 the same. .

On the other hand, the object to be measured has a measurement point mark on its surface. In the method of the embodiment, the measurement unit 4 is placed on the upper surface of the object and measured, but the measurement point mark is an indication at that time. Since it is often difficult to directly attach the mark to the upper surface of the object, in this embodiment, the measurement sheet 9 is placed on the upper surface of the object, and the measurement point mark 91 is provided on the measurement sheet 9. .

The measurement sheet 9 is a film or thin plate, and may not be flexible. The measurement point mark 91 is a concave portion provided in the measurement sheet 9 in this example. For example, it is conceivable to cut a thin metal plate with precision and form a concave portion as the measurement point mark 91.

The measurement point mark 91 is provided as a position on which each leg pin 51 of the measurement unit 4 is raised. Therefore, a number of measurement point marks 91 are provided at intervals equal to the arrangement interval of the three leg pins 51. In the example of FIG. 8, since the three leg pins 51 are provided at positions corresponding to the vertices of a right-angled isosceles triangle, the measurement point marks 91 are provided at positions corresponding to the intersection points of the right-angled grids, respectively. The distance between the vertical and horizontal distances (distance between the centers of the concave portions) of each measurement point mark 91 is equal to the spacing between the three leg pins 51.

The depth of the concave portion as each measurement point mark 91 is made to be uniform with precision. The opening of the recess is slightly larger than the thickness of the leg pin 51. In addition, the lower end of each leg pin 51 may be a conical shape, and the respective measurement point marks 91 may be pivoted (triggered).

*

* The procedure for measuring the flatness of the object is basically the same as in the first embodiment. For example, the measurement unit 4 is placed on the upper surface of the object by first allowing the lower end of the leg pin 51 to enter the three lower measurement point marks 91. In this state, a three-point measurement step is performed. That is, the level 6 is operated, and the measurement data is transmitted to the arithmetic processing unit 7 via radio. Next, the measurement unit 4 is placed so that the lower end of the leg pin 51 enters the three measurement point marks 91 on the right, and the measurement is carried out in the same manner. Thereafter, the measurement is performed on all the measurement point marks 91 while changing the direction in which the measurement point units are shifted in a zigzag manner as shown in FIG. 4. The measurement point mark 91 on the upper right is measured by changing the direction of the measurement unit 4 by 180 degrees.

In this way, the measurement data obtained in each of the three-point measurement steps are subjected to arithmetic processing to calculate the top view of the upper surface of the object. The calculation processing is also basically the same as in the first embodiment. In this embodiment, the arrangement interval of the measurement point mark 91 (that is, the arrangement interval of the leg pins 51) becomes a constant (a value that is already known), and calculation processing is performed in the form of incorporation thereof to measure the flatness.

In addition, the plan view in this embodiment is displayed as the difference in the height of the point immediately below each measurement point mark 91, and can also be said to be the same effect as the surface roughness.

The flatness measurement method of this embodiment is suitably performed, for example, when manufacturing the base plate 2 and checking the roughness of the upper surface. In addition, when the device is made by making a mechanism portion with respect to the base plate 2, and when used for a certain period of time, the base plate 2 may deteriorate, resulting in curvature or the like on the upper surface. ) Is also performed suitably when deterioration is checked.

In this embodiment, the term "leg pin" is widely interpreted. Since the leg pins 51 are for securing a certain distance to the upper surface of the measuring plate 5, they do not necessarily need to be called "pins", and may be, for example, protrusions such as a hemispherical shape.

Moreover, the measurement point mark does not necessarily need to be a recess, and may be a simple mark formed by a method such as printing. However, the structure in which the leg pin 51 is fitted into the concave portion is suitable because it is easy to accurately position the measurement unit 4. In addition, the measurement point mark may be directly provided on the upper surface of the object.

In addition, the calculation process for calculating the flatness from the measurement result of each three-point measurement step may be performed by the operator by hand calculation, not only by software or by hardware. When the number of pins is small, there may be cases where it is convenient.

In addition, in each of the above methods, the arrangement of the pin 3 and the measurement point mark 91 need only be known, and it is not necessary to be the scale of the checkerboard. For example, the separation distances in the X direction and the Y direction may be different. In this case, the separation distance w1 in the X-direction and the separation distance w2 in the Y-direction are only given as different constants, and can be performed similarly otherwise. Moreover, it may be the case where it is not the intersection point of a right angle grid, for example, it may be a rhombic grid shape. In this case, the angle of the grating is given as a constant, correction is made to the angle with respect to the measuring direction of the level 6, and then arithmetic processing is performed to measure the flatness.

Moreover, as an apparatus to which each method is applied, there may be other apparatuses, such as a photo-alignment apparatus, in addition to the above-described exposure apparatus.

1 pin unit 2 base board
3 pin 4 measuring unit
5 Measuring plate 51 Leg pin
6 level 61 transmitter
62 Receiver 7 Operation processing unit
8 core 9 measurement sheet
91 measuring point mark

Claims (1)

A flatness measuring method for covering a top surface of an object with a measurement sheet having a plurality of measurement point marks already known in a horizontal arrangement, and measuring a flatness in the horizontal direction of the top surface of the object,
A measuring unit having a flat upper surface, a level attached to the measuring board, and vertically extending downwardly from the lower surface of the measuring board, and a measuring unit having three leg pins of uniform length from the upper surface of the measuring board are used. How to do it,
The arrangement of the multiple measurement point marks is the same as the arrangement of the three leg pins of the measurement unit even when any three measurement point marks adjacent to each other are selected,
Among the multiple measurement point marks, three measurement point marks that are adjacent to each other are selected, and the level of the inclination of the measurement plate in two orthogonal two horizontal directions is leveled, with the leg pins of the measurement unit raised on the three selected measurement point marks. Method comprising a three-point measuring step to measure by,
It is a method of measuring a plan view by sequentially performing a three-point measuring step for each of the three measuring point marks,
The second and subsequent three-point measurement step is a step of repeatedly selecting and measuring one of the selected measurement point marks, and the measurement point mark selected above is a measurement point mark other than the measurement point mark selected in the previous three-point measurement step. May be-
It is a method to measure the inclination of the upper surface of the measuring plate by the level for all the measuring point marks by sequentially performing the three-point measuring step.
And calculating the difference between the height of the measurement point mark at the highest position and the measurement point mark at the lowest position from the inclination of the upper surfaces of the two horizontal measurement plates in each three-point measurement step. Floor plan measurement method.

Images