CN109073351B

CN109073351B - Flatness measuring method and pin height adjusting method

Info

Publication number: CN109073351B
Application number: CN201880001042.3A
Authority: CN
Inventors: 金内伸朗
Original assignee: Adtec Engineering Co Ltd
Current assignee: Adtec Engineering Co Ltd
Priority date: 2017-03-26
Filing date: 2018-02-21
Publication date: 2021-06-04
Anticipated expiration: 2038-02-21
Also published as: KR20190094447A; WO2018180047A1; KR102013090B1; CN113295077A; JP6392395B1; CN113295077B; CN109073351A; KR102337802B1; KR20200083669A; KR20180119589A; JP2018163033A

Abstract

The invention provides a practical technique capable of simply measuring the flatness of a surface such as an imaginary surface formed by the upper ends of a large number of pins. In a state that a measuring unit (4) provided with a level gauge (6) on a measuring plate (5) which has a flat upper surface and a flat lower surface and has a uniform thickness is placed on three adjacent pins (3) in a large number of pins (3), the inclination of the measuring plate (5) in two orthogonal horizontal directions is measured by the level gauge (6), and the steps are sequentially performed on the three pins (3). In the second and subsequent steps, one of the pins (3) selected before is selected repeatedly, and the inclination of the measurement plate (5) is measured for all the pins (3). The difference in height between the pin (3) having the highest upper end and the pin (3) having the lowest upper end is calculated as the flatness according to the inclination of the measurement plate (5).

Description

Flatness measuring method and pin height adjusting method

Technical Field

The present invention relates to a technique for determining the flatness of a surface such as a virtual surface formed by the upper ends of a large number of pins.

Background

A certain surface becomes a flat surface with high accuracy is often required as a performance of a product. In this case, a certain surface may be a virtual surface (virtual surface) or may be a surface of an actual component.

An imaginary plane formed by the upper ends of a large number of pins has a high flatness, and is required for an apparatus that operates an object while holding the object using such pins, for example. More specifically, in the manufacture of various electronic products and various display products, photolithography is performed to form minute shapes on the surface of a substrate. In photolithography, there is an exposure step in which a substrate is held horizontally and a predetermined pattern of light is irradiated onto the substrate. In the exposure step, a structure for holding the substrate by a large number of pins in a vertical posture is sometimes adopted in accordance with a requirement such as to minimize a contact area with the substrate.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2015-18927

Disclosure of Invention

Problems to be solved by the invention

In the exposure apparatus as described above, the substrate needs to be held in a horizontal posture with high accuracy from the viewpoint of obtaining an exposure pattern with high accuracy. This means that: in the case of a structure in which the substrate is held by a large number of pins, it is necessary for the virtual plane formed by the upper ends of the pins to have a high degree of flatness.

However, the inventors have conducted investigations and have not yet found a practical technique capable of easily measuring the flatness of an imaginary plane formed by the upper ends of a large number of pins.

The present invention has been made in view of the above, and an object thereof is to provide a practical technique capable of easily measuring the flatness of a surface such as an imaginary plane formed by the upper ends of a large number of pins.

Means for solving the problems

In order to solve the above-mentioned problems, the invention described in claim 1 of the present application is a flatness measuring method for measuring, as flatness of a virtual plane formed by the tips of a large number of pins, a difference in the position in the height direction of the upper ends of the large number of pins arranged in the horizontal direction in a known and vertically extending manner,

the flatness measuring method is a method using a measuring unit including a measuring plate having flat upper and lower surfaces and a uniform thickness; and a level gauge mounted above the measuring plate,

the flatness measuring method includes a three-point measuring step of selecting three adjacent pins among a large number of pins, measuring the inclination of a measuring plate in two orthogonal horizontal directions by a level gauge in a state where a measuring unit is placed on the selected three pins,

the flatness measuring method measures the flatness by sequentially performing three-point measuring steps on each of three pins,

the three-point measurement step after the second time is a step of repeating the measurement by selecting one of the pins selected before,

the flatness measuring method is a method for measuring the inclination of a measuring plate by a level for all pins by sequentially performing three-point measuring steps,

the flatness measuring method includes: and calculating a difference in height between the pin having the highest upper end and the pin having the lowest upper end based on the inclination of the side top plate in the two horizontal directions in each three-point measurement step.

In order to solve the above-mentioned problems, the invention according to claim 2 is a flatness measuring method for measuring a flatness in a horizontal direction of an upper surface of an object having a large number of measurement point marks arranged in a horizontal direction,

the flatness measuring method is a method using a measuring unit, the measuring unit including: an assay plate having a flat upper surface; a level mounted above the assay plate; and three leg pins vertically extending downward from the lower surface of the measurement plate and having a uniform length from the upper surface of the measurement plate,

the arrangement of the plurality of measurement point marks is the same as the arrangement of the three leg pins of the measurement unit when any adjacent three measurement point marks are selected,

the flatness measuring method includes a three-point measuring step of selecting three adjacent measuring point marks among a large number of measuring point marks, measuring the tilt of the measuring plate in two orthogonal horizontal directions by a level gauge in a state where leg pins of the measuring unit are placed on the three selected measuring point marks, respectively,

the flatness measuring method measures flatness by sequentially performing three-point measuring steps for each of three measuring point marks,

the three-point measurement step of the second and subsequent times is a step of repeating measurement by selecting one of the measurement point markers selected previously,

the flatness measuring method measures the inclination of the upper surface of the measuring plate by a level for all measuring point marks by sequentially performing three-point measuring steps,

the flatness measuring method includes: and calculating a difference in height between the measurement point mark at the highest position and the measurement point mark at the lowest position based on the inclination of the upper surface of the measurement plate in the two horizontal directions in each three-point measurement step.

In order to solve the above-mentioned problems, the invention according to claim 3 is a pin height adjusting method for adjusting a protrusion height of each pin from a base in a pin unit including the base and a large number of pins attached to an upper surface of the base and extending vertically upward and capable of adjusting a protrusion height of each pin, the method including:

a flatness measuring step of measuring a difference in height direction positions of the upper ends of the plurality of pins as a flatness of a virtual plane formed by the tips of the plurality of pins; and

an adjustment step of adjusting the projecting height of each pin based on the measurement result of the flatness in the flatness measurement step,

the flatness measuring step is a step of using a measuring unit including a measuring plate having a flat upper surface and a flat lower surface and a uniform thickness and a level gauge attached to the measuring plate, and includes a three-point measuring step of selecting three adjacent pins among a large number of pins, measuring the inclination of the measuring plate in two orthogonal horizontal directions by the level gauge in a state where the measuring unit is placed on the three selected pins,

the flatness measuring step is a step of measuring flatness by sequentially performing three-point measuring steps for each of the three pins,

the three-point measurement step after the second time is a step of repeating the measurement by selecting one of the pins selected previously,

the flatness measuring step is a step of measuring the inclination of the measuring plate by the level with respect to all the pins by sequentially performing three-point measuring steps,

the flatness measurement process includes: a step of calculating the difference in height between the pin having the highest upper end and the pin having the lowest upper end based on the inclination of the measurement plate in the two horizontal directions in each three-point measurement step,

the adjustment step is a method of adjusting the projecting height of each pin so that the difference in height measured in the flatness measurement step is reduced.

In order to solve the above problem, in addition to the above technical means 3, the invention according to claim 4 is: the adjusting step is a step of interposing a spacer between the base plate and the pin, and is a step of selecting a thickness of the spacer based on a measurement result in the flatness measuring step.

In order to solve the above problem, an invention according to claim 5 is, in addition to the

above claim

3 or 4, characterized in that: after the adjustment step, the flatness measurement step is performed again, and it is determined whether or not the difference in height between the upper ends of the pins falls within a predetermined range, and if not, the adjustment step is performed again.

Effects of the invention

As will be described below, according to the invention described in claim 1 of the present application, the flatness of the virtual plane formed by the upper ends of a large number of pins can be easily measured. The tool used for measurement is also a simple tool in which a level gauge and a measurement plate are combined, and therefore can be realized at low cost. Therefore, this method is an extremely practical measurement method.

In addition, according to the invention described in claim 2, the flatness of the upper surface of the object can be easily measured. The tool used for measurement is also a simple tool in which the level gauge, the measurement plate, and the leg pin are combined, and therefore can be realized at low cost. Therefore, this method is an extremely practical measurement method.

Further, according to the invention described in claim 3, since the flatness is measured by repeating the measurement step using the measurement unit, and the pin height is adjusted based on this, the measurement result can be obtained and adjusted by a simple procedure. Therefore, even when the measurement and adjustment are repeated, it is not troublesome and troublesome.

In addition to the above-described effects, according to the invention of claim 4, since the spacer is used, the projecting height of each pin can be adjusted easily and reliably.

Further, according to the invention recited in claim 5, in addition to the above-described effects, there is provided a method which is applicable to a case where a high degree of flatness is particularly required.

Drawings

Fig. 1 is a schematic perspective view of a pin unit for implementing the flatness measuring method according to the first embodiment.

Fig. 2 is a schematic perspective view of a measurement unit used in the method of the first embodiment.

Fig. 3 is a schematic plan view illustrating the flatness measuring method according to the first embodiment.

Fig. 4 is a schematic plan view illustrating the flatness measuring method according to the first embodiment.

Fig. 5 is a schematic perspective view showing a main part of an arithmetic process for calculating the flatness from each measurement data in the flatness measuring method according to the embodiment.

Fig. 6 is a diagram schematically showing an example of execution of the operation processing procedure by the table calculation software.

Fig. 7 is a schematic front view illustrating a pin height adjusting method according to an embodiment.

Fig. 8 is a perspective view showing an outline of the flatness measuring method according to the second embodiment.

Detailed Description

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

The invention of this application is a method for measuring the flatness of a certain surface, but its embodiments are roughly divided into: a method of measuring the flatness of a virtual plane formed by the upper ends of a large number of vertically extending pins, and a method of measuring the flatness of the upper surface of a member.

Hereinafter, a method of measuring the flatness of a virtual plane formed by the upper ends of a large number of pins will be described as a first embodiment. Fig. 1 is a schematic perspective view of a pin unit for implementing the flatness measuring method according to the first embodiment.

The pin unit 1 for implementing the flatness measuring method of the embodiment includes: a base plate 2, and a large number of pins 3 mounted on the upper surface of the base plate 2. As shown in fig. 1, a large number of pins 3 are installed to stand vertically. The upper surface of the base 2 is a flat surface with a required level of accuracy. Each pin 3 is mounted as: the height of the protrusion from the upper surface of the base plate 2 is constant. For example, each pin 3 is of the same length and is mounted by screwing. Therefore, the upper ends of the pins 3 should theoretically be located on the same imaginary horizontal plane. However, as a result of the dimensional accuracy and mounting accuracy (e.g., screwing depth) of each pin 3 and the flatness accuracy of the upper surface of the base 2 affecting each other, the upper ends of the pins 3 are rarely located at the same height with the required accuracy. That is, the virtual plane formed by the upper ends of the pins 3 may not have a desired flatness. The method of an embodiment detects this by measurement.

As shown in fig. 1, the pins 3 are arranged at positions on the checkerboard (at intersections of the squares). The adjacent pins 3 are all equally spaced.

Fig. 2 is a schematic perspective view of the measurement unit 4 used in the method of the first embodiment. The measurement unit 4 shown in fig. 2 includes: a measuring plate 5, and a level 6 mounted on the measuring plate 5.

The measurement plate 5 is positioned between each pin 3 to be measured and the level gauge 6, and thus has a required flatness. That is, the measurement plate 5 has a substantially flat upper surface and a substantially flat lower surface, and has a constant thickness. The material of the measurement 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 shape of a right-angled isosceles triangle which is chamfered.

As the level 6, a digital two-axis level is used in this embodiment. That is, the level 6 can measure the tilt of the measurement plate 5 in two orthogonal horizontal directions.

In this embodiment, the level 6 communicates data via wireless communication. The level 6 includes: a built-in transmission unit 61, and a reception unit 62 that receives the measurement data transmitted from the transmission unit 61. The receiver 62 functions as a remote controller for controlling the level gauge 6. The transmission unit 61 and the reception unit 62 perform wireless communication by specifying appropriate specifications such as low-power wireless, infrared communication, and Bluetooth (registered trademark). The level 6 can be produced by using, for example, a sakuba motor as a manufactured SEL-121 BM.

The measurement unit 4 is used together with an arithmetic processing unit 7 that performs arithmetic processing for measuring flatness. Various configurations can be assumed as the arithmetic processing unit 7, but in this embodiment, a general-purpose computer such as a desktop personal computer is used. The receiving unit 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 provided with a program for processing the measurement data output from the level gauge 6 to calculate the flatness.

Next, a flatness measuring method using the measuring unit 4 will be described with reference to fig. 3 and 4. Fig. 3 and 4 are schematic plan views illustrating a flatness measuring method according to the first embodiment.

The flatness measuring method of the embodiment is as follows: in order to be able to measure the inclination of the measurement plate 5 in two orthogonal horizontal directions, the following are performed in order: a step of selecting three adjacent pins 3 out of the large number of pins 3, and measuring the inclination of the measurement plate 5 with the level 6 in a state where the measurement unit 4 is placed on the selected three pins 3 (hereinafter, referred to as a three-point measurement step). "sequentially" means sequentially for each of the three pins 3. The second and subsequent three-point measurement steps are the steps of performing measurement in which one of the three pins 3 selected previously is selected repeatedly (in common).

In fig. 3, the arrangement direction of the pins is defined as the X direction and the Y direction. The number of pins is m in the X direction and n in the Y direction. For simplicity of explanation, the measurement direction (the directions of both axes) of the level 6 is the same as the X direction and the Y direction. Therefore, the base 2 is disposed in advance with high accuracy so that the pin arrangement direction coincides with the measurement direction of the level 6 (positioning).

In the pin arrangement shown in fig. 3, the lower left pin is denoted as P for identifying each pin₁₁Let the upper right pin be P_mn. Then, the lowest column is designated as P₁₁、P₂₁、···P_m1Its upper column is set to P₁₂、P₂₂、···P_m2. Similarly, the uppermost row is P_1n、P_2n、···P_mn。

In the flatness measuring method according to the embodiment, the inclination of the measuring plate 5 is measured by repeatedly selecting one pin 3 and sequentially selecting three adjacent pins 3, but in this case, it is important to be able to identify the three selected pins 3. Although the method can be realized in software, in this embodiment, the order of selecting three pins 3 is determined and the order is not mistaken.

To explain a more specific example, as shown in fig. 3 (1), in the first three-point measurement step, three pins P at the bottom left are selected₁₁、P₂₁、P₁₂To perform a three-point measurement procedure. Relative to P₁₁、P₁₂、P₂₁The measurement unit 4 is placed so as to straddle them, and the level 6 is operated to measure the tilt of the measurement plate 5. The measurement data is the inclination of the measurement plate 5 in the XY direction, and the data is transmitted from the transmission unit 61 to the reception unit 62, from the receiving section 62 to the arithmetic processing unit 7. Then, the first three-point measurement step is ended.

Next, as shown in (2) of fig. 3, three pins of the right-side adjacent group are selected. I.e. selecting P₂₁、P₃₁、P₂₂The three-point measurement procedure was also performed. In this case, P₂₁Is a pin that is repeated with one pin in the previous three-point measurement step. Three pins P of a group adjacent to the right are likewise selected₃₁、P₄₁、P₃₂And carrying out a three-point measurement step. Repeating the same action on P_(m-1)1、P_m1、P_(m-1)2After the three-point measurement step, the three-point measurement step for the lowermost pin 3 is completed.

Next, a three-point measurement step was performed for the pins in the second row from the bottom. That is, as shown in (1) of FIG. 4, the measurement unit 4 is shifted upward as it is, and P is set_(m-1)2、P_m2、P_(m-1)3A three-point measurement procedure was performed. In this case, P_(m-1)2Is a duplicate of one pin in the previous three-point measurement step.

Then, three pins P for the left side thereof_(m-2)2、P_(m-1)2、P_(m-2)3The three-point measuring step is performed, and thereafter the three-point measuring step is performed while sequentially shifting the position to the left side. Then, three pins P at the leftmost side₁₂、P₂₂、P₁₃After the three-point measurement step is performed, the three-point measurement step for the second row of pins is completed.

Thereafter, the measurement unit 4 is shifted upward in the original posture, and the three pins P immediately above the measurement unit are aligned₁₃、P₂₃、P₁₄A three-point measurement procedure was performed. Then, the three-point measurement step is performed for each of the three pins while sequentially shifting the pins to the right side this time.

Thus, as indicated by arrows in fig. 4 (2), the three-point measurement process is performed for each of the three pins while changing the direction (zigzag shape) every time the row is changed. After the three-point measurement step is performed up to the uppermost end (right end in this example), the orientation of the measurement plate 5 is changed by 180 degrees as shown in fig. 4 (3)And a three-point measurement step is performed. This is for the pin at the end of the uppermost column (pin P in this example)_mn) And (4) carrying out measurement. This is the final three-point measurement step, and thus the acquisition of measurement data ends as a whole. In addition, in the final three-point measuring step, the pin P is positioned with respect to the three-point measuring step immediately before the final three-point measuring step_(m-1_)nAnd a pin P_m(n-1)These two pins are repeated. Therefore, in the last three-point measuring step, two pins are repeated with respect to the previous three-point measuring step.

In this way, the three-point measurement step is performed for all the pins while selecting every three adjacent pins, and measurement data is obtained. Then, the target flatness is obtained by performing an arithmetic processing step of applying an appropriate arithmetic processing to the obtained measurement data. This point will be explained below.

Fig. 5 is a schematic perspective view showing a main part of an arithmetic process for calculating the flatness from each measurement data in the flatness measuring method according to the embodiment. Fig. 5 shows the processing of the measurement data obtained in the first three-point measurement step.

In FIG. 5, each pin P is inserted₁₁、P₂₁、P₁₂Is set to be H₁₁、H₂₁、H₁₂. As for the height, a horizontal plane as a reference is required, and may be, for example, the upper surface of the base 2. In FIG. 5, the pin P₁₂Height H of₁₂Top, pin P₂₁Is the lowest, but this is only one example of a measurement result.

Now, with the pin P₁₁Height H of₁₁As a reference, the difference in height is made positive in the case of being higher than that, and negative in the case of being lower than that. In this case, the pin P₂₁Relative to the pin P₁₁And on the same line in the X direction, the pin P₁₂Relative to the pin P₁₁On the same straight line in the Y direction, the differences are represented by the following

formulas

1 and 2.

dH₁＝w·tanθ_x1(formula 1)

dH₂＝w·tanθ_γ1(formula 2)

In formula 1, dH₁Is H₂₁Relative to H₁₁Difference of (2), dH₂Is H₂₁Relative to H₁₁The difference in (a). Theta_X1Is the angle of inclination in the X direction, theta_Y1The inclination angle in the Y direction is the measurement data in the three-point measurement step. w is the separation interval in the XY direction of each pin.

The positive and negative of the inclination angle will be described, and in fig. 5, the pin P is used₁₁The origin is defined as the positive angle of the X-direction inclination angle, which is defined as the counterclockwise direction with respect to the X-direction on the right side of the drawing sheet of fig. 3. For the Y direction, the pin P is also used₁₁The origin is a positive angle in which the direction toward the upper side on the paper surface of fig. 3 is defined as a plus side and the counterclockwise direction with respect to the plus side is defined as an inclination angle in the Y direction.

In this manner, the heights H are calculated separately₂₁Relative to height H₁₁Difference in height H of₁₂Relative to height H₁₁The difference in (a).

Next, for its adjacent three pins P₂₁、P₃₁、P₂₂The measured data of (2) were investigated. In this case, the height H is defined by the

expressions

3 and 4₃₁Relative to height H₂₁Difference in height H of₂₂Relative to height H₂₁The difference of (a) is calculated separately.

dH₃＝dH₁+W·tanθ_X2(formula 3)

dH₄＝dH₂+w·tanθ_Y2(formula 4)

In the

formulas

3 and 4, dH₃Is H₃₁Relative to H₂₁Difference of (2), dH₄Is H₂₂Relative to H₂₁The difference in (a). Also, theta_X2Is measured data of the inclination angle in the X direction, theta_Y2The measured data is the tilt angle in the Y direction. When the calculation results of

expressions

1 and 2 are substituted for

expressions

3 and 4, the two measured values in the second three-point measurement step are obtainedA pin P₃₁、P₂₂Height H of₃₁、H₂₂Relative to the height H of₁₁A difference.

Hereinafter, although the description will be omitted, the pin P is obtained from the measurement data in the third three-point measurement step₄₁Pin P₃₂Height of (D) relative to height H₁₁The pin P is obtained from the measurement data in the fourth three-point measurement step₅₁Pin P₄₂Height of (D) relative to height H₁₁The difference in (a).

By applying the calculation result to the measurement data in the next three-point measurement step in this way, the height of all the pins is determined for the lower left pin P₁₁Height H of₁₁The difference in (a).

In this way, the pin with the highest position at the upper end and the pin with the lowest position can be identified from all the pins, and the difference in height between the two can be used as the measurement result of the flatness.

In the above-described processing of the measurement data, the measurement is performed by reversing the orientation of the measurement unit 4 with respect to the measurement data in the last three-point measurement step, and therefore the positive and negative of the inclination angle are determined by reversing the positive and negative with respect to the X direction and the Y direction, respectively.

A more specific example will be described with respect to the calculation processing step, and the above-described calculation can be easily performed by using so-called table calculation software. In this regard, an example will be described with reference to fig. 6. Fig. 6 is a diagram schematically showing an example of execution of the operation processing procedure by the table calculation software.

In fig. 6, the three-point measurement step number is input to a certain cell row a, the X-direction inclination angle in the measurement data of the corresponding three-point measurement step is input to a certain cell row B, and the Y-direction inclination angle is input to another cell row C.

Further, the pin heights (strictly speaking, differences in height) calculated in accordance with the measurement data in the three-point measurement step are input to the other cell rows D to F. In fig. 6, in each three-point measurement step, a pin located at the apex angle (angle of 90 degrees) of the right isosceles triangle is referred to as a "triangle origin pin", and the height of the upper end of this pin is input to the cell row D. The pin located in the X direction with respect to the triangular origin pin is referred to as an "X-direction pin", and the height of the upper end of the pin is input to the cell row E. The pin located in the Y direction with respect to the triangular origin pin is referred to as a "Y-direction pin", and the height of the upper end of the pin is input to the cell row F.

More specifically, in the example of FIG. 6, pin P is input at cell D2₁₁Is equal to 0, pin P is input at element E2₂₁At the height of the input pin P of unit F2₁₂Of (c) is measured. Cell E2 is a value calculated by applying the measurement data of cell B2 to equation 1 (embedding calculation result), and cell F2 is a value calculated by applying the measurement data of cell C2 to equation 2. In order to automatically perform such calculation, calculation expressions are input in advance to the units E2 and F2.

The measurement data in the second three-point measurement step is input to the third cell row and calculated. In this case, the pin P is input at the unit D3₂₁The link of the cell is set so that the value of the cell E2 is copied as it is for each calculation formula. Inputting the pin P at element E3₃₁At the height of the input pin P of unit F3₂₂Of (c) is measured. Cell E3 is a value calculated by applying the measurement data of cell B3 to equation 1 (embedding calculation result), and cell F3 is a value calculated by applying the measurement data of cell C3 to equation 2. In order to automatically perform such calculation, a link and a calculation formula are set in advance. Fig. 6 shows an example in which the separation distance w of each pin 3 is 100 mm.

Hereinafter, although description will be omitted, links and calculation expressions are similarly set in advance for the cells in each row, and when measurement data is input to the cell row B and the cell row C, the links and calculation of the cells in the cell rows D to F are updated, and the difference in the pin heights is automatically calculated.

In addition, in the measurement data in the last three-point measurement step, the pins P are measured_mnCalculation of the height of (A), the pin P may be_m(n-1)The height of (2) may be calculated as a reference, and the pin P may be used_(m-1)nThe height of (d) is calculated as a reference, and any one of the heights is set in advance.

In the arithmetic processing using the table calculation software, the links and the calculation expressions are appropriately set for the respective cells, and the lower left pin P is used₁₁The heights of the upper ends of all the pins 3 are determined as a reference, and the difference between the highest value and the lowest value of the upper ends is determined as a flatness.

The measurement data is transmitted from the receiving unit of the level 6 to the arithmetic processing unit 7 via the USB, but it is preferable to appropriately set a microprogram in the table calculation software so that the measurement data is sequentially input to the cell row B and the cell row C. In other words, a microprogram is provided for inputting the inclination angle in the X direction to the effective cell of the cell column B and the inclination angle in the Y direction to the effective cell of the cell column C when the measurement data is received, and then enabling the cell column B and the cell column C in the next row.

According to the flatness measuring method of the above embodiment, the flatness of the virtual plane formed by the upper ends of the large number of pins 3 can be easily measured. The tool used for measurement is a simple tool in which the level gauge 6 and the measurement plate 5 are combined, and therefore can be realized at low cost. Therefore, this method is an extremely practical measurement method.

In the flatness measuring method of the above embodiment, the order of selecting each of the three pins 3 may be other than the above. After the measurement is performed with respect to the lowermost column, the measurement unit 4 may be shifted in the same direction in order from the second column from the bottom toward the left end. Therefore, the repeated pins are sometimes not the pins selected in the three-point measurement step immediately before. It is important not to mistake which group of three pins 3 is to be measured, and the group of three pins 3 is selected in accordance with a predetermined order and the measurement is performed for all the pins 3.

In the above-described viewpoint, two pins 3 can be selected repeatedly at all times, but the calculation is easily complicated, and therefore, it is preferable to make the number of three-point measurement steps repeated only one as large as possible. In the above example, the number of the pins 3 for repeating the calculation of the height at the upper end is considerably large, but the calculation may be performed by overwriting, or the initial calculation result may be retained.

In the above description, the measurement unit 4 is disposed at each position while being held by the operator, but the measurement unit may be automated by a robot or the like. For example, the robot may learn the position of the arrangement of the measurement unit 4 and the program thereof.

The measuring unit 4 is preferably a biaxial level meter, but may be implemented by a single axis type. In the case of the single axis type, the orientation of the level 6 can be changed by 90 degrees on the measurement plate 5. Then, two measurements were performed with the orientation of the level 6 changed by 90 degrees with respect to each of the three pins 3. The arithmetic processing unit 7 may be built in the level gauge 6 or may be attached to the level gauge 6, and the arithmetic processing unit 7 may not be provided separately from the level gauge 6. The arithmetic processing unit 7 may be provided as a part of a substrate processing apparatus such as an exposure apparatus.

As the shape of the measurement plate 5, other shapes such as an L-shape may be considered in addition to the triangular shape. Among these, a triangular shape is preferable because a space for fixing the level 6 is required, and if the level 6 is not fixed to the center of gravity of the measurement plate 5, the measurement plate 5 is likely to float (move away from the upper end of any one of the pins 3).

Further, although measurement may be performed in a state where the measurement unit 4 is placed on four pins 3, and calculation of flatness is theoretically possible, it is difficult to bring the measurement plate 5 into contact with all the upper ends of the four pins 3, and calculation processing becomes complicated, and therefore a structure where the measurement unit 4 is placed on three pins 3 is preferable.

In the above description, the XY coincidence between the two axes of the level 6 and the arrangement direction of the pins 3 was described, but even if the XY coincidence is not coincident, the XY coincidence can be measured as long as the deviation is known. The above-described calculation process may be applied after correction in a plan view is performed based on the deviation angle between the measurement direction of the level 6 and the arrangement direction of the pins 3. Among them, the arithmetic processing is easier when the two axes of the level 6 coincide with the arrangement direction of the pins 3.

Next, an embodiment of the invention of the pin height adjusting method will be explained. Fig. 7 is a schematic front view illustrating a pin height adjusting method according to an embodiment.

The pin height adjusting method of the embodiment is a method using the flatness measuring method of the above-described embodiment. That is, after the flatness is measured as described above, the difference in height of the upper ends of the pins 3 can be suppressed within a certain range by adjusting the projecting height of each pin 3 based on the measurement result.

In this embodiment, a spacer (fine spacer) 8 is used to adjust the projecting height of each pin 3. The spacer 8 is a part having a thickness of a high accuracy and known, for example, a ring shape. As described above, each pin 3 is fixed to the base plate 2 by screwing, but the screw portion at the lower end of each pin 3 is smaller than the central opening of the spacer 8, and the body portion above the screw portion is smaller than the central opening of the spacer 8. Therefore, each pin 3 can be screwed into the base plate 2 with the spacer 8 interposed therebetween. By appropriately selecting the kind (thickness) and the number of the spacers 8, the protruding height of the pin 3 from the base plate 2 can be adjusted.

In the pin height adjusting method of the embodiment, the above-described flatness measuring method is performed to specify the pin 3 (the pin P in the above-described example)₁₁) The difference in height of the upper ends was measured as a reference. Next, the difference is recalculated with the pin 3 having the highest height at the upper end as a reference. Since the differences are all negative values, the type and number of the pads 8 are selected based on this (so that the differences become zero). In this case, there is often no combination of pads 8 that exactly matches the difference, and in this case, the combination of the closest (approximate) pads 8 is selected.

For example, when the difference in height of a certain pin 3 is-69 μm and a spacer 8 having a thickness of 10 μm and a spacer 8 having a thickness of 50 μm are present, two spacers 8 having a thickness of 10 μm and one spacer 8 having a thickness of 50 μm are prepared, and the pin 3 is screwed into the base plate 2 while they are sandwiched by overlapping. In this way, the pin 3 is re-screwed into all the other pins 3 while sandwiching the different amount of the shim 8 so that the position of the upper end matches the highest pin 3.

In the method of the embodiment, after the height is adjusted in this manner, the flatness is measured again. That is, the measurement units 4 are sequentially placed on the three pins 3, and three-point measurement steps are performed. Then, the difference in the height of the upper end of each pin 3, which is the measurement result obtained, was confirmed. In this case, if the difference in height falls within a certain range, the adjustment is completed, but in many cases, the difference does not fall within the certain range. A certain range is the required accuracy of the flatness and refers to the extent to which the difference in height of the upper ends of the pins 3 is allowed. The reason why the range is not entered is as follows: an error in initial measurement, an influence due to selection of the approximate spacer 8, a slight variation in thickness of the spacer 8, a variation in the screw-in depth at the time of screw-in after adjustment, and the like. These interactions often result in inconsistent heights of the upper ends.

In any case, if the range is not within a certain range, the adjustment is performed again. In the next adjustment, it is preferable to remove or add the spacer 8 to make a minimum adjustment necessary. That is, the average value of the heights of the upper ends of the pins 3 is calculated, and the positive and negative adjustment amounts are calculated based on the average value. Then, if the adjustment amount is positive, the type and number of the pads 8 closest to the adjustment amount are determined and added. If the adjustment amount is negative, the number of spacers 8 that is similar to the negative adjustment amount is removed.

Further, the flatness is measured again, and when the flatness falls within a certain range, the adjustment is completed. If the measurement is not performed, the spacer 8 is inserted and removed again to perform adjustment, and the adjustment and measurement are repeated until the measurement is performed within a predetermined range. The adjustment is usually completed by about 2 to 3 times of measurement and insertion/extraction.

According to the pin height adjusting method of the embodiment, since the flatness is measured by repeating the three-point measuring step using the measuring unit 4 and the pin height is adjusted based on the flatness, the measurement result can be obtained and adjusted by a simple procedure. Therefore, even when the measurement and adjustment are repeated, it is not troublesome and troublesome.

Further, since the spacer 8 is used, the projecting height of each pin 3 can be adjusted easily and reliably. As another method, the depth of screwing of each pin 3 may be adjusted.

Further, the method of the above embodiment in which measurement and adjustment are repeated is suitable for use in a case where flatness requirements are particularly high.

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

The first embodiment is a method of measuring the flatness of an imaginary plane formed by the upper ends of a large number of pins 3, but the second embodiment is a method of measuring the flatness of the surface (actual surface) of an object. This method is suitably performed, for example, when measuring the flatness of the upper surface of a member that provides a horizontal plane as a reference on a mechanical structure such as the base 2.

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

At least the upper surface of the measurement plate 5 is a flat surface. Flatness is defined by the relationship with the accuracy of the measured flatness.

The measuring plate 5 is likewise triangular (here, right-angled isosceles triangle shaped), and the level 6 is fixed to the center of the measuring plate 5. As the level 6, a digital wireless type two-axis level is also suitably used.

The three leg pins 51 extending downward need to be uniform in length at least from the upper surface of the measuring plate 5. Typically, the bottom surface of the measurement plate 5 is made flat as in the upper surface, so that the thickness of the measurement plate 5 is uniform and the length of the leg pins 51 is all the same.

On the other hand, the object to be measured has a measurement point mark on the surface. The method of the embodiment is to place the measurement unit 4 on the upper surface of the object to perform measurement, and the measurement point mark is a mark in this case. Since it is often difficult to provide the mark directly on the upper surface of the object, in this embodiment, the measurement piece 9 is covered on the upper surface of the object, and the measurement point mark 91 is provided on the measurement piece 9.

The measurement piece 9 may be film-shaped or thin plate-shaped, and may not have flexibility. The measurement point mark 91 is a recess provided in the measurement piece 9 in this example. For example, it is conceivable to form a concave portion as the measurement point mark 91 by cutting a thin metal plate with high accuracy.

The measurement point mark 91 is provided at a position on which each leg pin 51 of the measurement unit 4 is placed. Therefore, the measurement point marks 91 are provided in a large number at the same interval as 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 isosceles triangle, the measurement point marks 91 are provided at positions corresponding to the intersections of squares. The vertical and horizontal separation distances (distances between the centers of the concave portions) of the measurement point marks 91 are the same as the arrangement intervals of the three leg pins 51.

The depth of the concave portion of each measurement point mark 91 is uniform with high accuracy. The opening of the recess is slightly larger than the thickness of the leg pin 51. Further, the lower end of each leg pin 51 may be tapered, and each measurement point mark 91 may be pivoted (mortar-shaped).

The procedure for measuring the flatness of the object is basically the same as that of the first embodiment. For example, the measurement unit 4 is initially placed on the upper surface of the object so that the lower end of the leg pin 51 enters the three lower left measurement point marks 91. In this state, a three-point measurement step was performed. That is, the level 6 is operated, and the measurement data is transmitted to the arithmetic processing unit 7 via wireless. Next, the measurement unit 4 is placed so that the lower end of the leg pin 51 enters the right three measurement point marks 91, and measurement is performed in the same manner. Thereafter, measurement is performed for all the measurement point marks 91 while changing the direction in which the measurement point elements are displaced in a zigzag manner as shown in fig. 4. Then, the measurement is performed with the orientation of the measurement unit 4 changed by 180 degrees with respect to the measurement point mark 91 on the upper right.

The measurement data obtained in each three-point measurement step is subjected to arithmetic processing, and the flatness of the upper surface of the object is calculated. The arithmetic processing is basically the same as that of the first embodiment. In this embodiment, the arrangement interval of the measurement point marks 91 (i.e., the arrangement interval of the leg pins 51) is a constant (known value), and the flatness is measured by performing an arithmetic process in a form in which the above-mentioned constant is substituted.

The flatness in this embodiment is expressed as a difference in height between points directly below the measurement point marks 91, and may be said to be equivalent to the surface roughness.

The flatness measuring method according to this embodiment is suitable for use in inspecting the roughness of the upper surface of the base 2 when the base is manufactured, for example. Further, if a mechanism part is attached to the base 2 to construct a certain apparatus, and the apparatus is used for a certain period of time, the base 2 may be deteriorated and the upper surface may be bent, and the apparatus is suitable for use in inspecting the deterioration of the base 2.

In this embodiment, the term "leg pin" can also be broadly interpreted. The leg pin 51 is a member for securing a constant distance from the upper surface of the measurement plate 5, and therefore does not necessarily need to be called a "pin", and may be a protrusion such as a hemispherical shape, for example.

The measurement point mark does not necessarily need to be a recessed portion, and may be a simple mark formed by a method such as printing. Among these, the structure in which the leg pin 51 is fitted into the recess is preferable because the measurement unit 4 can be more easily and accurately disposed. Further, the measurement point mark may be provided directly on the upper surface of the object.

The calculation process for calculating the flatness from the measurement results of the three-point measurement steps may be performed not only automatically by software or hardware but also manually by an operator. In the case where the number of pins is small, manual calculation is sometimes simpler.

In each of the above methods, the arrangement of the pins 3 and the measurement point marks 91 may be known, and may not be checkered. For example, the separation distances may be different in the X direction and the Y direction. In this case, only the separation distance w1 in the X direction and the separation distance w2 in the Y direction are given different constants, and the other operations are performed in the same manner. Further, the intersection points may not be square grids, and may be, for example, a diamond grid. In this case, the angle of the grid is given as a constant, and the flatness is measured by correcting the angle with respect to the measurement direction of the level 6 and performing calculation processing.

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

Description of the reference symbols

A pin unit; a base plate; a pin; an assay unit; measuring a plate; a leg pin; a level; 61.. a transmitting part; a receiving portion; an arithmetic processing unit; a gasket; measuring a sheet; measuring point markers.

Claims

1. A flatness measuring method for measuring the flatness of a virtual plane formed by the top ends of a large number of pins arranged in a horizontal direction and extending vertically with a known position in the height direction, the method comprising the steps of,

the flatness measuring method is a method using a measuring unit including a measuring plate having flat upper and lower surfaces and a uniform thickness and a level gauge mounted on the measuring plate,

the flatness measuring method includes a three-point measuring step of selecting three adjacent pins from a large number of pins, measuring the inclination of the measuring plate in two orthogonal horizontal directions with a level gauge in a state where a measuring unit is placed on the selected three pins,

the flatness measuring method is a method for measuring flatness by sequentially performing three-point measuring steps for each of three pins,

the flatness measuring method includes: and calculating a difference in height between the pin having the highest upper end and the pin having the lowest upper end based on the inclinations of the two measurement plates in the horizontal direction in each three-point measurement step.

2. A pin height adjusting method for adjusting the protruding height of each pin from a base plate in a pin unit having the base plate and a large number of pins attached to the upper surface of the base plate and extending vertically upward,

it is characterized by comprising:

a flatness measuring step of measuring a difference in the height direction position of the upper ends of the plurality of pins as the flatness of a virtual plane formed by the tips of the plurality of pins; and

an adjustment step of adjusting the projecting height of each pin according to the measurement result of the flatness in the flatness measurement step,

the flatness measuring step is a step of using a measuring unit including a measuring plate having a flat upper surface and a flat lower surface and a uniform thickness and a level gauge attached to the measuring plate, and includes a three-point measuring step of selecting three adjacent pins among a large number of pins and measuring the inclination of the measuring plate in two orthogonal horizontal directions by the level gauge in a state where the measuring unit is placed on the selected three pins,

the flatness measuring step is a step of measuring the inclination of the measuring plate by the level for all the pins by sequentially performing three-point measuring steps,

the flatness measurement process includes: calculating a difference in height between the pin having the highest upper end and the pin having the lowest upper end based on the inclinations of the two measurement plates in the horizontal direction in each three-point measurement step,

3. The pin height adjustment method according to claim 2,

the adjusting step is a step of interposing a spacer between the base plate and the pin, and is a step of selecting a thickness of the spacer in accordance with a measurement result in the flatness measuring step.

4. The pin height adjusting method according to claim 2 or 3,

after the adjustment step, the flatness measuring step is performed again, and it is determined whether or not the difference in height between the upper ends of the pins falls within a predetermined range, and if not, the adjustment step is performed again, the predetermined range being the required precision of flatness.