KR102337802B1 - Flatness measurement method and pin-height adjustment method - Google Patents

Abstract

[assignment]
It provides a practical technology that can easily measure the flatness of the same plane as the virtual plane formed by the top of a number of pins.
[Solution]
A measuring unit 4 having a flat upper surface and lower surface and having a level 6 attached to a measuring plate 5 having a uniform thickness is placed on three adjacent pins 3 among a plurality of pins 3 . In this state, the inclination of the measuring plate 5 in two orthogonal horizontal directions is measured with 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 with respect to all the pins 3 while repeatedly selecting one of the pins 3 selected up to that point. From the inclination of the measuring plate 5, the difference in height between the pin 3 at the highest position and the pin 3 at the lowest position is calculated as a plan view.

Description

How to measure flatness and how to adjust pin height

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

It is often required as a product performance that any surface is flat with high precision. Any surface in this case may be a virtual surface (virtual surface), or may be the 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 upper end of a plurality of pins has a high planarity. If a more specific example is shown, in manufacture of various electronic products and various display products, photolithography is performed in order to create a microscopic shape on the surface of a board|substrate. In photolithography, an exposure process of irradiating a substrate with light of a predetermined pattern while maintaining the substrate horizontally exists. In the exposure step, in response to a request such as making the contact area to the substrate as small as possible, a structure for holding the substrate by a plurality of pins in a vertical posture is sometimes employed.

Japanese Patent Laid-Open No. 2015-18927

In the exposure apparatus as described above, from the viewpoint of obtaining an exposure pattern with high precision, it is necessary for the substrate to maintain a horizontal posture with high precision. This means that, in the case of a structure for holding a substrate with a plurality of fins, an imaginary surface formed at the top of these fins needs to have a high-precision flatness.

However, from what the inventor has investigated, there is currently no practical technique capable of simply measuring the planarity 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 that can easily measure the flatness of the same plane as the virtual plane formed by the upper ends of a plurality of pins.

In order to solve the above problem, the invention described in claim 1 of this application already knows the horizontal arrangement, and the tip of the plurality of pins forms a difference in the height direction of the upper ends of the plurality of vertically extending pins. A flatness measurement method for measuring as a flatness of an imaginary surface, the method comprising:

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

A three-point measurement step of selecting three adjacent pins from among a plurality of pins and measuring the inclination of the measuring plate in two orthogonal horizontal directions with a level with a measuring unit placed on the selected three pins A method comprising

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

The three-point measurement step after the second time is a step of repeatedly selecting one of the pins selected up to that time and performing measurement,

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

A configuration comprising the step of calculating the difference in height between the pin at the highest position and the pin at the lowest position from the inclination of the two horizontal measuring plates in each of the three-point measuring steps have

Further, in order to solve the above problem, the invention described in claim 2 is a flatness measuring method for measuring the flatness in the horizontal direction of the upper surface of an object provided with a plurality of measurement point marks for which the horizontal arrangement is already known,

A measuring unit having a measuring plate having a flat upper surface, a level attached to the measuring plate, and three leg pins extending vertically downward from the lower surface of the measuring plate and having a uniform length from the upper surface of the measuring plate is used. how to do it,

The arrangement of the plurality of measuring point marks is such that even when any three measuring point marks adjacent to each other are selected, the arrangement of the three leg pins of the measuring unit is the same;

Three measuring point marks adjacent to each other are selected among the plurality of measuring point marks, and the inclination of the measuring plate in two orthogonal horizontal directions is leveled with the leg pins of the measuring unit placed on the selected three measuring point marks, respectively. A method comprising a three-point measurement step of measuring by

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

The three-point measurement step after the second time is a step of repeatedly selecting and measuring one of the three measurement point marks selected up to that point,

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

It has a configuration including the step of calculating the difference in height between 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 .

In addition, in order to solve the above problem, the invention described in claim 3 includes a base plate and a plurality of pins attached to the upper surface of the base plate and extending vertically upward, and the protrusion height of each pin is adjustable. In the unit, a pin height adjustment method for adjusting the protrusion height of each pin from a base board, comprising:

a planarity measuring step of measuring the difference in the positions of the upper ends of the plurality of pins in the height direction as a plan view of a virtual surface formed by the tips of the plurality of pins;

It has an adjustment process of adjusting the protrusion height of each pin according to the measurement result of the flatness in the flatness measurement process,

The flatness measurement process is a process using a measurement unit having a flat upper surface and lower surface and having a uniform thickness, and a measurement unit consisting of a level attached to the measurement plate, and selecting three adjacent pins among a plurality of pins, A process comprising a three-point measuring step of measuring the inclination of the measuring plate in two orthogonal horizontal directions with a level with the measuring unit placed on the selected three pins,

The flatness measurement process is a process of measuring the flatness 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 one of the three selected until then and performing the measurement,

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

The flatness measuring step is a step of calculating the difference in height between the pin at the highest position and the pin at the lowest position from the inclination of the two horizontal measuring plates in each of the three-point measuring steps contains,

The adjustment process has the structure of the method of adjusting the protrusion height of each pin so that the difference in height measured in the planarity measurement process may be made small.

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

Moreover, in order to solve the said subject, in the invention of Claim 5, in the structure of the said Claim 3 or 4, after performing the said adjustment process, the said flatness measuring process is performed again, The difference in the height of the upper end of each pin It is determined whether or not is within a certain range, and if not, the adjustment process is performed again.

As will be described below, according to the invention described in claim 1 of this application, it is possible to simply measure the flatness of the virtual surface formed by the upper ends of a plurality of pins. Also about the tool used for measurement, since it is a simple thing combining 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 of Claim 2, the flatness of the upper surface of an object can be measured simply. As for the tool used for measurement, it can be realized at low cost because it is a simple combination of a level, a measuring plate, and a leg pin. For this reason, it becomes an extremely practical measuring method.

Further, according to the invention described in claim 3, the flatness is measured by repeating the measuring step using the 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 when measurement and adjustment are repeated, it does not take effort and does not become complicated.

Moreover, according to invention of Claim 4, in addition to the said effect, since the shim is used, adjustment of the protrusion height of each pin can be performed simply and reliably.

Moreover, according to the invention of Claim 5, in addition to the said effect, the method suitable when especially high flatness is requested|required is provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective schematic diagram of the pin unit to which the planar view measuring method of 1st Embodiment is implemented.
Fig. 2 is a perspective schematic view of a measurement unit used in the method of the first embodiment;
Fig. 3 is a plan schematic view showing the plan view measuring method according to the first embodiment.
Fig. 4 is a plan schematic view showing the plan view measuring method according to the first embodiment.
Fig. 5 is a perspective schematic view showing an essential part of an arithmetic process for calculating a plan view from each measurement data in the plan view measuring method of the embodiment.
Fig. 6 is a diagram schematically showing an example of execution of the arithmetic processing step by the table calculation software.
It is a front schematic diagram which showed the pin height adjustment method which concerns on embodiment.
It is a perspective view which shows the outline of the planar view measuring method of 2nd Embodiment.

Next, an embodiment (hereinafter, an 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, and the embodiment is a method of measuring the flatness with respect to an imaginary surface formed by the upper ends of a plurality of vertically extending pins, and with respect to the upper surface of a certain member It is largely distinguished by the method of measuring the flatness.

Hereinafter, as 1st Embodiment, the method of measuring the planarity of the virtual surface which the upper end of many pins makes is demonstrated. BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective schematic diagram of the pin unit to which the planar view measuring method of 1st Embodiment is implemented.

The pin unit 1 to which the planarity measuring method of embodiment is implemented is provided with the base board 2 and the many pins 3 attached to the upper surface of the base board 2 . As shown in FIG. 1, many pins 3 are vertically erected and attached. The upper surface of the base board 2 is a horizontal and flat surface of the required precision. Each pin 3 is attached so that the protrusion height from the upper surface of the base board 2 may become constant. For example, each pin 3 is all of the same length, and is attached by screw-type insertion. Accordingly, the top of each pin 3 will theoretically be located on the same imaginary horizontal plane. However, as a result of mutual influence of factors, such as dimensional accuracy of each pin 3, attachment precision (insertion depth, etc.), and planar precision of the upper surface of the base board 2, the upper end of each pin 3 is the same It is less likely to be positioned with the precision required for a height position. That is, the virtual surface formed by the upper end of each pin 3 may not have a necessary flatness. The method of the embodiment detects this by measurement.

In addition, as shown in FIG. 1, each pin 3 is arrange|positioned at the position of the grid image of a checkerboard (on each intersection of a right-angled grid). All of the adjacent pins (3) have the same spacing.

Fig. 2 is a perspective schematic view of a measurement unit 4 used in the method of the first embodiment. The measuring unit 4 shown in FIG. 2 is equipped with the measuring plate 5 and the level 6 attached on the measuring plate 5. As shown in FIG.

Since the measuring plate 5 is located between each pin 3 which is a measurement object, and the level 6, it is supposed to have the flatness required. That is, the measuring plate 5 is a plate of a constant thickness having a sufficiently flat upper surface and a lower surface. Although there is no restriction|limiting in particular in the material of the measuring plate 5, There are many cases of a metal like stainless steel or aluminum. As shown in FIG. 2, the measuring plate 5 has the shape of a chamfered right isosceles triangle.

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

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

In addition, the measurement unit 4 is used together with the arithmetic processing unit 7 which performs arithmetic processing for the measurement of a plan view. As the arithmetic processing unit 7, although various structures can be assumed, in this embodiment, the general-purpose computer like 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. In the arithmetic processing unit 7 , a program for calculating a plan view by processing the measurement data output from the level 6 is mounted.

Next, the plan view measuring method using the measuring unit 4 is demonstrated using FIG.3 and FIG.4. 3 and 4 are plan schematic views showing the plan view measurement method according to the first embodiment.

The flatness measuring method of the embodiment selects three adjacent fins 3 among a plurality of fins 3 so that the inclination of the measuring plate 5 in two orthogonal horizontal directions can be measured, A method of sequentially measuring the inclination of the measuring plate 5 with the level 6 with the measuring unit 4 placed on the selected three pins 3 (hereinafter referred to as the three-point measuring step) to be. "Perform sequentially" means to perform sequentially with respect to each of the three pins 3 . The three-point measurement step after the second time is a step of performing a measurement in which one of the three pins 3 selected up to that point is overlapped (commonly) selected.

In FIG. 3, the arrangement direction of each pin is set to an X direction and a Y direction. It is assumed that the number of pins is m in the X direction and n in the Y direction. In addition, in order to simplify description, the measurement direction (two-axis direction) of the level 6 shall be the same thing as an X-direction and a Y-direction. Accordingly, the base board 2 is precisely arranged (positioned) in advance so that the arrangement direction of the pins coincides with the measurement direction of the level 6 .

In the arrangement of pins shown in FIG. 3 , in order to identify each pin, the lower left pin is referred to as P ₁₁ , and the upper right pin is _referred to as P mn . And, set the lowest column to P ₁₁ , P ₂₁ ,… Let P _m1 , and the column above it, P ₁₂ , P ₂₂ , ... Let it be _{P m2.} In the same way, the top row is P _1n , P _2n , … Let it be _{P mn.}

In the planarity measurement method of the embodiment, while selecting one pin 3 overlappingly, three pins 3 adjacent to each other are sequentially selected to measure the inclination of the measurement plate 5. At this time, it is important to It is to be able to specify the selected three pins (3). As this method, it is also possible to implement by software, but in this embodiment, the order of selecting the three pins 3 is determined, and it is performed by making sure that this order is not wrong.

To explain a more specific example, as shown in Fig. 3(1), in the first three-point measurement step, the three pins on the lower left, that is, P ₁₁ , P ₂₁ , P ₁₂ are selected, and the three-point measurement step is performed. . Raise the measuring unit 4 so as to span P ₁₁ , P ₁₂ , and P ₂₁ , and operate the level 6 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 is sent from the reception unit 62 to the arithmetic processing unit 7 . With this, the first three-point measurement step is finished.

Next, as shown in FIG.3(2), three pins of a group adjacent to the right are selected. That is, P ₂₁ , P ₃₁ , and P ₂₂ are selected and the same three-point measurement step is performed. 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 the group adjacent to the right are selected to perform a three-point measurement step. If the same operation is repeated and _{the three-point measurement step is performed for P (m-1)1} , P _m1 , P _(m-1)2 , the three-point measurement step for the pin 3 in the lowest row ends .

Next, a three-point measurement step is performed for the pins in the second row from the bottom. That is, as shown in FIG. 4( 1 ), the measuring unit 4 is moved upward as it is, and a three-point measurement step is performed for _P(m-1)2 , _Pm2 , P _{(m-1)3 .} In this case, P _(m-1)2 is a pin overlapping with that in 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, while sequentially shifting to the left, 3 Perform 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 pins in the second column is finished.

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

In this way, as indicated by arrows in Fig. 4(2), the three-point measurement step is performed for each of the three pins while changing the direction (in a zigzag pattern) whenever the column changes. Then, after performing the three-point measurement step to the end of the uppermost column (the right end in this example), as shown in Fig. 4(3), the direction of the measurement plate 5 is changed 180 degrees to perform the three-point measurement step. . This is to measure the pin at the end of the topmost column (pin P _{mn in this example).} This is the last three-point measurement step, with which the acquisition of measurement data is entirely ended. In the last three-point measurement step, two pins of the pin P _(m-1)n and the pin Pm _(n-1) overlap with the three-point measurement step of the previous three-point measurement step. Therefore, in the last three-point measurement step, there are two pins overlapping with the previous three-point measurement step.

In this way, a three-point measurement step is performed for all pins while selecting three adjacent pins one by one, and each measurement data is obtained. And a target plan view is obtained by performing an arithmetic processing step of applying an appropriate arithmetic process to the obtained measurement data. Next, this point is demonstrated.

Fig. 5 is a perspective schematic view showing an essential part of an arithmetic process for calculating a plan view from each measurement data in the plan view measuring method of the embodiment. In Fig. 5, processing of the measurement data obtained in the first three-point measurement step is shown.

5, and each pin P _11, P _21, P ₁₂ to the height of the top of the _{H 11, H 21, H 12} . Although the height needs a horizontal plane used as a reference|standard, it can be set as the upper surface of the base board 2, for example. 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, the pin P ₂₁ is on the same straight line in the X direction with respect to the pin P _{11 , and the pin P 12} is on the same straight line in the Y direction with respect to the pin P _{11 .} is displayed

In Equation 1, dH ₁ is the difference between _{H 21} with respect to _{H 11 , and dH 2} is the difference between _{H 21} with respect to H _{11 .} θ _xi is an inclination angle in the X direction, θ _Y1 is an inclination angle in the Y direction, and is measurement data in the three-point measurement step, respectively. w is the spacing in the XY direction of each pin.

When explaining the positive and negative of the inclination angle, in Fig. 5, with the pin P ₁₁ as the origin, the X direction facing the right side on the paper plane of Fig. 3 is the + side, and the counterclockwise direction based on this is the inclination angle of the X direction. be a positive angle in . Also in the Y direction, the pin P ₁₁ is taken as the origin, and the Y direction obliquely upward on the paper plane of FIG. 3 is taken as the + side, and this is a positive angle in the inclination angle of the counterclockwise Y direction based on this.

In this way, _{the difference between the height H 21} and the height H ₁₂ with respect to the _{height H 11} is calculated, respectively.

Next, the measurement data of the three adjacent pins P ₂₁ , P ₃₁ , and P _{22 are examined.} In this case, the difference between the height H ₂₂ of the difference of height H ₃₁ of heights H _21, H ₂₁ in height is calculated respectively by the equation 3 or 4.

In Equations 3 and 4, dH ₃ is the difference between _{H 31} with respect to H _{21 , and dH 4} is the difference between _{H 22} with respect to H _{21 .} Similarly, θ _X2 is measurement data of an inclination angle in the X direction, and θ _Y2 is measurement data of an inclination angle in the Y direction. With respect to Expressions 3 and 4, when the calculation results of Expressions 1 and 2 are substituted, the two pins P ₃₁ , P ₂₂ height H ₃₁ and H ₂₂ height H ₁₁ measured in the second three-point measurement step are The difference is found for

Hereinafter, although description is abbreviate|omitted, the difference with respect to the height H _{11 of the height of pin P 41} and pin P ₃₂ is calculated|required by the measurement data in the 3rd 3-point measurement step, and the measurement in the 4th 3-point measurement step The difference between the heights of pins P ₅₁ and P _{42 with respect to the height H 11} is obtained from the data.

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

By doing so, it becomes possible to specify the pin with the highest position and the lowest pin among all the pins, so that the difference in height between the two can be obtained, and the measurement result of the flatness can be obtained.

In addition, in the processing of each measurement data, the measurement data in the last three-point measurement step is measured while the direction of the measurement unit 4 is reversed. Determine the positive and negative of each.

When a more specific example is described about the calculation processing step, the above calculations can be performed simply by using so-called table calculation software. An example of this point is demonstrated using FIG. Fig. 6 is a diagram schematically showing an example of execution of an arithmetic processing step by the table calculation software.

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

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

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

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 input pin P ₂₁ in the cell D3, it is a link of the cell set to be a value of the cell as the copy E2 each formula. The height of pin P ₃₁ is input to cell E3, and the height of pin P ₂₂ is input to cell F3. Cell E3 is a value calculated by applying the measurement data of cell B3 to Equation 1 (result of the interpolation calculation), and cell F3 is a value calculated by applying the measurement data of cell C3 to Equation 2. A link or a calculation expression is set in advance so that this calculation is performed automatically. In addition, FIG. 6 sets it as the example in the case where the separation distance w of each pin 3 is 100 mm.

Hereinafter, although a description is omitted, links and calculation formulas are preset in the same way for cells in each row, and when measurement data is input to cell columns B and C, the links and calculations of cells in cell columns D to F are updated. Thus, the difference in height of each pin is automatically calculated.

In addition, in the measurement data in the last three-point measurement step, about the calculation of the height of _{fin P mn} , you may calculate on the basis of the height of _{fin P m(n-1) , and fin P(m-1)n} It may be calculated on the basis of the height of , or one of them is preset.

In the calculation processing using the table calculation software as described above, by appropriately setting links and calculation formulas for each cell, the height of the upper end of all pins 3 is obtained based on _{pin P 11 at the lower left corner,} 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 arithmetic processing unit 7 via USB. If a 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, when the measurement data is received, the inclination angle in the X direction is input to the active cell in cell column B, the inclination angle in the Y direction is input to the active cell in cell column C, and then cell column B and cell column C in the lower row. A macro program that activates .

According to the planarity measuring method of the above-described embodiment, the planarity of the virtual surface formed by the upper ends of the plurality of pins 3 can be simply measured. Also about the tool used for a measurement, since it is the simple thing which combined the level 6 and the measuring plate 5, it can implement|achieve at low cost. For this reason, it becomes an extremely practical measuring method.

In the planarity measurement method of the above embodiment, the order of selecting each of the three pins 3 may be other than that described above. After the measurement is performed for the lowest column, the measurement unit 4 may be sequentially moved in the same direction by returning to the left end for the second column from the bottom. Therefore, there are cases where the duplicated pin is not the pin selected in the previous 3-point measurement step. What is important is to make sure that the measurement for the set of the three pins 3 is not wrong, select the set of each three pins 3 in a predetermined order, and measure all the pins 3 .

From the above point of view, it is also possible to always have the two pins 3 to be selected overlappingly, but since the calculation tends to be complicated, it is preferable to make a pattern in which the number of overlapping three-point measurement steps is as many as possible. . In addition, in the above example, although there are many pins 3 by which the calculation of the height of an upper end is performed overlappingly, you may overwrite and you may make it calculate it, and you may make it hold|maintain the initial calculation result.

In the above description, it has been described that the measurement unit 4 is picked up by an operator and placed at each position, however, there may be cases where it is automated by a robot or the like. For example, there may be a case where the robot is taught the position of the arrangement of the measurement unit 4 and its routine.

Moreover, about the measurement unit 4, although a 2-axis type level machine is preferable, implementation is possible also with a 1-axis type. In the case of a single-axis type, the level 6 is configured so that the direction can be changed by 90 degrees on the measuring plate 5 . And with respect to each of the three pins 3, two measurements are performed in which the direction of the level 6 is changed by 90 degrees. In addition, the arithmetic processing unit 7 may have a structure in which the level 6 is built-in or is attached to the level 6 , and the arithmetic 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 a part of a substrate processing apparatus like an exposure apparatus.

As a shape of the measuring plate 5, other shapes, such as an L-shape other than a triangle, are also conceivable. However, if a space for fixing the level 6 is required, and if the level 6 is not fixed at the center position of the measurement plate 5, the measurement plate 5 will float (from the upper end of any one pin 3). A triangle is preferable from the thing which is easy to generate|occur|produce and the like.

Moreover, it is also conceivable to measure in the state where the measuring unit 4 is raised with respect to the four pins 3, and although calculation of a planar view is also possible theoretically, the measuring plate 5 is four pins 3 It is difficult to make contact with all the upper ends of the , but since the calculation process becomes complicated, the structure in which the measuring unit 4 is mounted on the three pins 3 is preferable.

In addition, in the said description, although it demonstrated that the two axes in the level 6 and XY of the arrangement direction of the pin 3 coincide, even if they do not coincide, if the shift|offset|difference is already known, a measurement is possible. What is necessary is just to apply the said arithmetic process after making a correction|amendment at the time of planar view according to the deviation angle of the measuring direction in the level 6 and the arrangement direction of the pin 3 . However, the arithmetic processing is simplified when the two axes in the level 6 and the arrangement direction of the pins 3 coincide.

Next, embodiment of the invention of the pin height adjustment method is described. Fig. 7 is a schematic front view showing a fin height adjustment method according to the embodiment.

The fin height adjustment method of embodiment uses the flatness measuring method of embodiment mentioned above. That is, after measuring the planarity as described above, the difference in the height of the upper end of each pin 3 is suppressed within a certain range by adjusting the protrusion height of each pin 3 according to the measurement result.

In this embodiment, the shim (precision spacer) 8 is used for adjustment of the projection height of each pin 3 . The shim 8 is, for example, an annular member with a high thickness and known with high precision. As described above, each pin 3 is fixed by threaded insertion with respect to the base plate 2, and the thread cutting portion at the lower end of each pin 3 is thinner than the central opening of the shim 8, and is threaded. The body portion above the portion is smaller than the central opening of the shim 8 . Accordingly, each pin 3 can be screwed into the base plate 2 with the shim 8 sandwiched therein. By appropriately selecting the type (thickness) and number of shims 8 , the protrusion height of the pins 3 from the base board 2 is adjusted.

In the fin height adjustment method of embodiment, the flatness measuring method mentioned above is implemented, and the difference in the height of an upper end is measured on the basis of the _{specific fin 3 (pin P 11 in the above example).} Next, the difference is calculated again based on the highest pin 3 at the top. Since the differences are all negative, the type and number of shims 8 are selected accordingly (so that the difference becomes zero). At this time, there is often no combination of shims 8 that fits the difference, and in that case, the closest (closest) shim 8 combination is selected.

For example, if the difference in height of a certain fin 3 is -69 μm, and there are a 10 μm thick core 8 and a 50 μm thick core 8, two 10 μm cores 8 are One shim 8 is prepared, and the said pin 3 is screw-inserted into the base board 2 by overlapping them. In this way, so that the position of the upper end is aligned with the highest pin 3, the pin 3 is inserted again while inserting the shim 8 as much as the difference for all the other pins 3.

In the method of embodiment, after adjusting a height in this way, a flatness is measured once more. That is, the measurement unit 4 is sequentially mounted on each of the three pins 3, and each three-point measurement step is performed. And the obtained measurement result, ie, the difference in the height of the upper end of each pin 3, is confirmed. In this case, if the difference in height falls within a certain range, this will end adjustment, but in most cases, it does not fall within a certain range. A certain range is a required precision of flatness, and relates to how much the difference in the height of the upper end of the pin 3 is permissible. Reasons for not falling within a certain range include errors at the time of initial measurement, influence by the selection of the approximate shim 8, slight variation in the thickness of the shim 8, variation in insertion depth at the time of screw insertion after adjustment, etc. to be. In many cases, they interact with each other, resulting in a deviation in the height of the top.

In any case, if it does not fall within a certain range, it will be adjusted again. In adjustment again, it is preferable to remove or add the shim 8, and to set it as necessary minimum adjustment. That is, the average value of the height of the upper end of each pin 3 is computed, and the adjustment amount of plus or minus is computed with it as a reference|standard. And, if it is a positive adjustment amount, the type and number of shims 8 closest to it are determined and added. If it is a negative adjustment amount, the long-lived shim 8 of the closest type is removed.

Then, the flatness is measured once more, and if it is within a certain range, the adjustment is completed. If it does not, remove and insert the shim (8) again, and adjust it, and repeat measurement and adjustment until it enters a certain range. Usually, adjustment is completed by measuring 2-3 times and removing and inserting.

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. can For this reason, even when measurement and adjustment are repeated, it does not take effort and does not become complicated.

Moreover, since the shim 8 is used, adjustment of the protrusion height of each pin 3 can be performed easily and reliably. As another method, the insertion depth of each pin 3 may be adjusted.

In addition, the method of the said embodiment which repeats measurement and adjustment is suitably employ|adopted especially when a high flatness is requested|required.

Next, the planarity measuring method of 2nd Embodiment is demonstrated. 8 is a perspective view schematically illustrating a plan view measurement according to the second embodiment.

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

The measurement unit 4 used in the second embodiment is slightly different from the first embodiment. That is, in 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 three leg pins ( 51) is vertically extended downwards.

The measuring plate 5 has at least a flat upper surface. The flatness is defined in relation to the precision of the flatness to be measured.

The measuring plate 5 is similarly triangular (here right-angled isosceles triangular shape), and the level 6 is being fixed to the center of the measuring plate 5. As shown in FIG. As the level 6, a digital wireless two-axis level level is preferably used similarly.

The three leg pins 51 extending downward must have at least a uniform length from the upper surface of the measuring plate 5 . Typically, this is achieved by making the lower surface of the measuring plate 5 a flat surface the same as the upper surface, making the thickness of the measuring plate 5 uniform, and making all 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. The method of the embodiment places the measurement unit 4 on the upper surface of the object to measure, and the measurement point mark is a mark at that time. Since it is often difficult to directly install the mark on the upper surface of the object, in this embodiment, the measurement sheet 9 is placed over the upper surface of the object, and the measurement point mark 91 is provided on the measurement sheet 9. .

The measurement sheet 9 may be in the form of a film or a thin plate, and may not be flexible. The measurement point mark 91 is a recess provided in the measurement sheet 9 in this example. For example, it is conceivable to precisely cut a thin metal plate and form a recess 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 placed. Accordingly, a plurality of measurement point marks 91 are provided 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 the right isosceles triangle, the measurement point marks 91 are respectively provided at positions corresponding to the intersections of the right-angled grid. The vertical and horizontal separation distances (distance between the centers of the recesses) of the respective measurement point marks 91 are equal to the spacing between the three leg pins 51 .

The depth of the concave portion as each measurement point mark 91 is precisely uniform. The opening of the concave portion is slightly larger than the thickness of the leg pin 51 . In addition, there is a case where the lower end of each leg pin 51 is conical, and each measuring point mark 91 is pivoted (triggered).

*

* The procedure for measuring the flatness of an object is basically the same as in the first embodiment. For example, the measuring unit 4 is mounted on the upper surface of the object with the lower end of the leg pin 51 entering the three measuring point marks 91 in the lower left at first. In this state, a three-point measurement step is performed. That is, the level 6 is operated to transmit the measurement data to the arithmetic processing unit 7 via wireless. Next, the measuring unit 4 is placed so that the lower end of the leg pin 51 enters the three measuring point marks 91 on the right side, and the measurement is performed in the same manner. Thereafter, the measurement is performed for all the measurement point marks 91 while changing the direction of shifting the measurement point unit in a zigzag manner similar to that shown in FIG. 4 . And about the measurement point mark 91 on the upper right, the direction of the measurement unit 4 is changed 180 degrees, and a measurement is performed.

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

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

The flatness measuring method of this embodiment is suitably performed, when the roughness of the upper surface is checked, when the base board 2 is produced, for example. In addition, if a mechanism is made for the base board 2 to constitute a certain device and used for a certain period of time, the base board 2 deteriorates and curvature or the like may occur in the upper surface. ) is also suitably performed when checking the deterioration of

In this embodiment, the term "leg pin" is widely interpreted. Since the leg pin 51 is for securing a certain distance with respect to the upper surface of the measuring plate 5, it is not necessarily a thing which can be called a "pin", and may be, for example, a protrusion such as a hemispherical shape.

In addition, the measurement point mark does not necessarily need to be a recessed part, and may be a simple mark formed by methods, such as printing. However, the structure in which the leg pins 51 are fitted in the recessed portion is suitable because it is easy to accurately position the measurement unit 4 . Also, there is a case where the measurement point mark is provided directly on the upper surface of the object.

In addition, with respect to the calculation processing for calculating the flatness from the measurement result of each three-point measurement step, not only the case where it is automatically performed by software or hardware, but the case where an operator may perform it by hand calculation may also be possible. When the number of pins is small, there may be cases where it is more convenient.

In addition, in each of the above methods, the arrangement of the pins 3 and the measurement point marks 91 may be already known, and the grid pattern may not be necessary. For example, the separation distance may be different from the X direction and the Y direction. 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 otherwise, the same can be performed. Moreover, it may be a case where it is not the intersection of a right-angled grid|lattice, for example, a rhombic grid type may be sufficient. In this case, the angle of the grid is given as a constant, and after correction is made to the angle with respect to the measurement direction of the level 6, arithmetic processing is performed, and the flatness is measured.

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 exposure apparatus mentioned above.

1 pin unit 2 base board
3 pin 4 measuring unit
5 Measuring plate 51 Leg pins
6 Level 61 Transmitter
62 Receiver 7 arithmetic processing unit
8 core 9 measurement sheet
91 Measuring Point Mark

Claims (1)

A planarity measuring method of measuring the flatness of the upper surface of the object in the horizontal direction by covering the upper surface of the object with a measurement sheet having a plurality of measurement point marks for which the horizontal arrangement is already known,
A measuring unit having a measuring plate having a flat upper surface, a level attached to the measuring plate, and three leg pins extending vertically downward from the lower surface of the measuring plate and having a uniform length from the upper surface of the measuring plate is used. how to do it,
The arrangement of the plurality of measuring point marks is such that even when any three measuring point marks adjacent to each other are selected, the arrangement of the three leg pins of the measuring unit is the same;
Three measuring point marks adjacent to each other are selected among the plurality of measuring point marks, and the inclination of the measuring plate in two orthogonal horizontal directions is leveled with the leg pins of the measuring unit placed on the selected three measuring point marks, respectively. A method comprising a three-point measurement step of measuring by
It is a method of measuring the flatness by sequentially performing the three-point measuring step for each of the three measuring point marks,
The three-point measurement step after the second time is a step of repeatedly selecting and measuring one of the measurement point marks selected up to that point, - the overlapping selected measurement point mark is a measurement point mark other than the measurement point mark selected in the immediately preceding three-point measurement step Rado -
It is a method of measuring the inclination of the upper surface of the measuring plate by means of a level for all the measuring point marks by sequentially performing the three-point measuring steps,
Comprising the step of calculating the difference in height between 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,
The measuring point mark is composed of a concave portion of a guiding type, and the lower end of the leg pin facing the measuring point mark is conical.

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