KR100681885B1 - Profilometry - Google Patents

Abstract

The present invention relates to a surface using a moiré system having a projection device having a projection grid and a light source for projecting light onto a workpiece through the projection grid, and an image forming device for forming a grid image formed by the light projected on the workpiece. A shape measuring method comprising the steps of: calculating reference phase data for a plurality of sample reference planes having different separation distances from the imaging device; Detecting a separation distance between the imaging device and the actual reference plane for the workpiece; Calculating measurement phase data of the surface of the workpiece using the moiré system; And calculating the data on the surface shape of the workpiece based on the reference phase data and the measurement phase data corresponding to the detected separation distance of the actual reference plane among the reference phase data. This makes it possible to measure the surface shape more precisely by using reference phases for a plurality of reference planes, and to lower the price of the moire system.

Description

Surface shape measurement method {PROFILOMETRY}

1 is a view showing the configuration of a moiré system according to the present invention,

2 is a view for explaining a method of obtaining a moire fringe in the surface shape measurement method according to the present invention,

3 is a view for explaining the relationship between the plurality of sample reference planes and the actual reference plane in the surface shape measurement method according to the present invention,

4 is a view for explaining a method for calculating reference phases for a plurality of sample reference planes in the surface shape measurement method according to the first embodiment of the present invention.

FIG. 5 is a diagram for describing a method of calculating reference phases for a plurality of sample reference planes in the surface shape measurement method according to the second embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

10: projection device 11: light source

12: projection grid 20: imaging device

21: imaging lens 22: imaging surface

30: control device 40: displacement measuring device

The present invention relates to a surface shape measurement method, and more particularly, to a surface shape measurement method for measuring the surface shape of the workpiece using reference phase data for a plurality of sample reference planes.

In general, the measurement of a three-dimensional shape having a shape such as a free-form surface is widely applied in various fields such as inspection of various workpieces, CAD / CAM, medical, solid modeling, and solder paste inspection of PCB substrates.

As the measurement technology of the three-dimensional shape, a method of measuring the entire curved shape by measuring one point on the curved surface using a contact type three-dimensional measuring device has been used. However, the method for measuring the curved shape by the contact type 3D measuring device has a disadvantage in that the measurement time is excessively required as a whole because the measuring object of the 3D shape must be measured one by one.

In order to solve the shortcomings of the contact type 3D measuring device, a moire technique for measuring a 3D shape in a non-contact manner using light has recently been applied. This moire technique provides an advantage of significantly reducing the measurement time compared to the conventional contact three-dimensional measurement method. In this case, the moiré technique generates a moire pattern having three-dimensional shape information about the measured object by irradiating light on the measured object to form a linear striped grid having a predetermined interval.

In the moiré technique, light is passed through a stripe grating and is projected onto the workpiece, causing the grid to cast shadows on the workpiece. Here, this shadow is curved according to the shape of the workpiece. Looking at the workpiece in this state, the undeformed straight-lined lattice and the shadows of the lattice overlap, resulting in a wavy contour pattern. This pattern is generally called moire fringe, and this moire fringe has shape information of the workpiece and analyzes it to measure the surface shape of the workpiece.

On the other hand, the projection moiré technique has been proposed for the precise measurement of the workpiece. In the projection moiré technique, the lattice is phase shifted for the precise analysis of the moire fringe, and the measurement result is superior to the previous measurement method, but the optical system has a rather complicated disadvantage.

Accordingly, PMP (Phase Measurement Profilometry) is proposed. The sine wave is illuminated on a fine projection grid, and the light passing through the projection grid is projected onto the measurement object. The phase was subdivided to the maximum. This results in a much more accurate phase than the other methods described earlier, resulting in good measurement results.

In general, in the method of measuring the surface shape using the Moire technique, the reference phase with respect to the reference plane is measured and calculated in advance, stored in a memory, and placed in the measuring device so that the reference plane among the surfaces of the workpiece coincides with the reference plane. The light is projected onto the measurement object to measure and calculate the phase of the surface of the measurement object. The shape information of the surface of the workpiece is obtained by measuring the distance from the reference plane to the surface of the workpiece based on the deviation of the phase of the previously stored reference plane and the surface of the measured workpiece.

By the way, for example, when measuring the shape of the solder paste formed on the PCB substrate, the surface of the PCB substrate is installed so as to match the reference plane, the height of the solder paste relative to the surface of the PCB substrate is measured, at this time When supporting both sides of the PCB board to fix the position of the PCB board, the PCB board may be bent. In this case, inconsistency between the surface of the PCB substrate and the reference surface becomes deeper toward the center of the plate surface of the PCB substrate, resulting in an error in the shape information of the solder paste formed on the PCB substrate. In addition, because of the π ambiguity, only the height of one phase of the grating can be measured, which limits the height that can be measured from the reference plane.When the PCB substrate is severely warped, the absolute height of the solder paste is beyond the measurable range This may happen.

In order to solve such a problem, in the surface shape measurement system using the conventional moire technique, the absolute position of the measurement object, that is, the separation distance between the measurement device and the measurement object is measured, and the measuring device itself is moved by using a driving means such as a servomotor. The error was compensated for by doing so. In this method, a separate transfer device for moving the measuring instrument has to be added, which requires an accuracy comparable to the measuring accuracy of the measuring instrument, which increases the price of the entire measuring system and increases the volume. There are disadvantages.

Accordingly, it is an object of the present invention to provide a surface shape measurement method that enables more accurate surface shape measurement by using reference phases for a plurality of reference planes and lowers the price of the moire system.

The object is, according to the present invention, a projection apparatus having a projection grid and a light source for projecting light onto the workpiece through the projection grid, and an imaging device for forming a grid image formed by the light projected on the workpiece A method of measuring a surface shape using a moiré system comprising: calculating reference phase data for a plurality of sample reference planes having different separation distances from the imaging device; Detecting a separation distance between the imaging device and the actual reference plane for the workpiece; Calculating measurement phase data of the surface of the workpiece using the moiré system; And calculating data on the surface shape of the workpiece based on the reference phase data and the measured phase data corresponding to the detected separation distance of the actual reference plane among the reference phase data. Is achieved by the method.

The calculating of the reference phase data for the plurality of sample reference planes may include: preparing a plurality of reference plane measurement objects that may be positioned at different distances from the imaging device in correspondence to each of the sample reference planes; ; Calculating reference phase data for the surface of each reference plane workpiece using the moiré system; And storing the calculated reference phase data for the surface of each reference plane measurement object as the reference phase data for each corresponding sample reference plane.

The calculating of the reference phase data for the plurality of sample reference planes may include: a sample reference plane measurement object which may be positioned at a distance corresponding to at least one sample reference plane of the plurality of sample reference planes from the imaging device; Providing a step; Calculating sample reference phase data on the surface of the sample reference plane measurement using the moiré system; Storing the calculated sample reference phase data as the reference phase data for the corresponding sample reference plane; Calculating and storing deviation information between the remaining sample reference plane and the sample reference plane corresponding to the sample reference phase data and the reference phase data for the remaining sample reference plane based on the sample reference phase data. Can also be.

Wherein the deviation information includes information on a separation distance δ _h between the remaining sample reference plane and the sample reference plane corresponding to the sample reference plane; The reference phase data for the remaining sample reference planes is

는 나머지 상기 표본 기준면에 대한 기준위상,

은 상기 표본 기준위상, g는 상기 투영격자의 격자간격, L_P는 상기 영사장치의 광원과 상기 표본 기준위상에 대응하는 상기 표본 기준면 간의 이격거리, f_P는 상기 광원과 상기 투영격자 사이의 이격거리, d는 상기 영사장치의 광축과 상기 결상장치의 광축 간의 이격거리이다)에 의해 산출될 수 있다.(here,

Is the reference phase for the remaining sample reference planes,

Is the sample reference phase, g is the lattice spacing of the projection lattice, L _P is the separation distance between the light source of the projection apparatus and the sample reference plane corresponding to the sample reference phase, f _P is the separation between the light source and the projection lattice Distance, d is the separation distance between the optical axis of the projection device and the optical axis of the imaging device.

In addition, the deviation information includes information on the separation distance δ _h between the remaining sample reference plane and the sample reference plane corresponding to the sample reference phase, and the reference phase data for the remaining sample reference plane is

는 나머지 상기 표본 기준면에 대한 기준위상, g는 상기 투영격자의 격자간격, f_P는 상기 영사장치의 광원과 상기 투영격자 사이의 이격거리, d는 상기 영사장치의 광축과 상기 결상장치의 광축 간의 이격거리, L_P는 상기 광원과 상기 표본 기준위상에 대응하는 상기 표본 기준면 간의 이격거리, L_C는 상기 결상장치의 결상렌즈와 상기 표본 기준위상에 대응하는 상기 표본 기준면 간의 이격거리, f_C는 상기 결상렌즈와 상기 결상장치의 수광면 간의 이격거리, x_i는 상기 영사장치의 광축과 상기 표본 기준위상에 대응하는 상기 표본 기준면 상의 한 점 간의 거리, △는 상기 투영격자의 초기위치이다)에 의해 산출될 수도 있다.(here,

Is a reference phase with respect to the remaining sample reference plane, g is a lattice spacing of the projection grating, f _P is a separation distance between the light source of the projection device and the projection grating, d is between the optical axis of the projection device and the optical axis of the imaging device The separation distance, L _P is the separation distance between the light source and the specimen reference plane corresponding to the specimen reference phase, L _C is the separation distance between the imaging lens of the imaging device and the specimen reference plane corresponding to the specimen reference phase, f _C is The separation distance between the imaging lens and the light receiving surface of the imaging device, x _i is the distance between the optical axis of the projection device and a point on the sample reference plane corresponding to the sample reference phase, Δ is the initial position of the projection lattice) May be calculated.

On the other hand, the object, according to another application of the present invention, in the method for measuring the surface shape of the substrate on which the solder paste is formed, partitioning the substrate into a plurality of measurement areas; Calculating data for the surface shape of the substrate on each measurement area using the surface shape measurement method for each measurement area; The surface shape of the substrate may be achieved by a method of measuring the surface shape of the substrate, based on data of the surface shape of the substrate on each measurement area. The measuring method is effective when applied to the shape measurement of the solder paste formed on the substrate.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In addition, the embodiment of the present invention will be described by using a phase measurement profile (PMP) as an example.

The moiré system, which is a measurement system for measuring the surface shape, has a projection apparatus 10 for projecting light onto the measurement object O through the projection grid 12, as shown in FIGS. 1 and 2, and a measurement object. An imaging device 20 for forming a grating image formed by the light projected on (O), and controlling the projection device 10 and the imaging device 20, and from the projection device 10 and the imaging device 20. And a control device 30 for calculating various data based on the data. In addition, a displacement measuring device 40 for measuring the displacement of the separation distance from the imaging device 20 to the measurement object (O).

The projection device 10 is disposed with a light source 11 for generating light at a position spaced apart from the reference plane RP on which the measurement object O is placed by a predetermined distance, and stripes between the reference plane RP and the light source 11. The grid is engraved projection grid 12. An imaging lens 21 is disposed at a position separated by a predetermined distance from the optical axis formed by the light source 11 and the projection grid 12 so that the light reflected from the measurement object O passes, and the light passing through the imaging lens 21 passes through the imaging lens 21. The light receiving unit is provided at one side of the imaging lens 21 to receive the light.

In general, it is preferable to use white light as the light source 11, and it is preferable to use a laser diode or a halogen light source 11 called a small size, light weight and relatively inexpensive semiconductor laser. Light generated from the light source 11 according to the present invention has a sine wave waveform.

Between the light source 11 and the projection lattice 12, a condenser lens (not shown) may be disposed to uniformly concentrate the light from the light source 11 on the projection lattice 12, and may be disposed close to the projection lattice 12. Between the projection grid 12 and the measurement object O, an unillustrated projection lens for projecting light passing through the projection grid 12 onto the measurement object O may be disposed.

Then, a projection unit (not shown) is coupled to the projection lattice 12 to micro-transfer the projection lattice 12 to increase the phase shift of the projection lattice 12. Here, it is preferable to use the PZT actuator which can move the projection grid 12 minutely as a conveyance part.

The optical axis of the projection optical system formed by the light source 11 and the projection grid 12 and the optical axis of the imaging optical system formed by the imaging lens 21 and the light receiving unit are parallel to each other, and the distance from the reference plane RP to the light source 11 and the reference plane ( It is preferable that the distance from the RP) to the imaging lens 21 is the same, since the calculation of the controller 30 can be simplified. In addition, the optical axis of the projection optical system and the optical axis of the imaging optical system are perpendicular to the reference plane RP.

The light receiving unit preferably uses a CCD (charge coupled device) camera as the image sensor, and the condenser lens, the projection lens, and the imaging lens 21 may be known lenses.

Displacement measuring device 40 measures the actual separation distance between the actual reference plane (RP) and the moire system, for example the imaging device 20 for the workpiece (O). As the displacement measuring device 40, a non-contact displacement measuring instrument such as a contact displacement measuring instrument, a linear variable differential transformer (LVDT), a laser displacement measuring instrument, or the like may be used.

According to the above structure, the light from the light source 11 is condensed by the condensing lens, passed through the projection grid 12, reflected from the measurement object O, and then reaches the light receiving portion through the imaging lens 21 to form an image. do. Accordingly, the moire fringe is obtained by the light formed in the light receiving unit. At this time, in order to implement algorithms such as 2, 3, 4 buckets or N buckets, the projection grid 12 is transferred at equal intervals through the transfer unit to shift the phase of the moire pattern. In a preferred embodiment of the present invention a four bucket algorithm is used.

Hereinafter, with reference to FIG. 2, the algorithm for measuring the height of the measured object O from the actual reference plane RP of the measured object O is demonstrated formally.

First, the distance between the light receiving surface 22 and the imaging lens 21 of the light receiving unit along the optical axis of the imaging optical system is referred to as f _C , and the distance from the imaging lens 21 to the reference surface RP is referred to as L _C. A distance between the light source 11 and the projection lattice 12 along the optical axis of the optical system is referred to as f _P , a distance from the light source 11 to the reference plane RP is referred to as L _P , and an arbitrary distance on the projection lattice 12 Points and corresponding points on the light receiving surface 22 are denoted by xg and xi, respectively.

Light incident from the light source 11 at a point xg on the projection grid 12 passes through the projection grid 12 and then enters a point (xo, h (xo)) on the measurement object O. The reflected light reflected from the point (xo, h (xo)) on the measurement object O passes through the center of the imaging lens 21 and reaches a point xi on the light receiving surface 22 of the light receiving portion.

At this time, the light transmittance T (xg) of the projection lattice 12 is expressed by Equation 1 below when the grating pitch is g.

[Equation 1]

, (△는 투영격자(12)의 초기위치)

, (△ is the initial position of the projection grid 12)

On the other hand, when the brightness of the light incident on the point xg of the projection grid 12 is I _P (xg), the light incident on the point (xo, h (xo)) of the measurement object passing through the projection grid 12 is measured. The brightness I _P (xo, h (xo)) is expressed as in Equation 2.

[Equation 2]

Here, using the geometrical relationship as in Equation 3, I _P (xo, h (xo)) can be represented as in Equation 4.

[Equation 3]

[Equation 4]

On the other hand, when the reflectance of one point (xo, h (xo)) of the measurement object O is R (xo, h (xo)), the brightness I of light incident on one point xi on the light receiving surface 22 of the light receiving unit (xi) can be expressed as in Equation 5.

[Equation 5]

Here, using the geometric relationship as shown in Equation 6, I (xi) can be represented as shown in Equation 7.

[Equation 6]

[Equation 7]

only,

는 식 8과 같이 나타낼 수 있다.Thus, phase

Can be expressed as shown in Equation 8.

[Equation 8]

과, 기준면(RP)에 대한 기준위상

은 각각 식 9 및 식 10에서와 같이 표현된다.Here, the measurement phase for the measured object (O) based on Equation 8

And the reference phase for the reference plane (RP)

Are expressed as in Equations 9 and 10, respectively.

[Equation 9]

[Equation 10]

은 측정위상과 기준위상 간의 차에 의해 식 11과 같이 나타낼 수 있다.Therefore, interference pattern phase for moiré pattern

Can be expressed as in Equation 11 by the difference between the measured phase and the reference phase.

[Equation 11]

If L _P = L _C , Equation 11 can be expressed as Equation 12.

[Equation 12]

Here, the height hi of the measurement object O from the reference plane RP is expressed as in Equation 13.

[Equation 13]

, (단,

)

, (only,

)

Meanwhile, in the moire system according to the present invention, reference phase data for a plurality of sample reference planes R1, R2, R3, R4, and R5 having different separation distances from the imaging device 20 is calculated in advance, so that the control device 30 It is stored in advance in a memory not shown. For example, the reference phase for each separation distance L _C is calculated in advance so that the separation distance L _C between the imaging lens 21 and the reference plane of the imaging device 20 has a plurality of values. Here, the distance L _P from the light source 11 also changes with respect to the plurality of sample reference planes R1, R2, R3, R4, and R5.

In addition, when the measurement object O is installed in the moire system to measure the surface shape, the actual reference plane RP of the imaging lens 21 and the measurement object O, for example, the measurement object using the displacement measuring device 40, is measured. Measure the actual separation distance from (O) to the reference surface, and apply the reference phase calculated by the L _C value corresponding to the measured actual separation distance to Eq. For example, the hi value of Equation 13 is calculated. Accordingly, in the case of measuring the surface shape of the workpiece O using the moiré system, an error generated when the measurement object O is installed on a specific reference plane of the moire system, or the corresponding object O of the moire system Even if correctly installed on a specific reference plane can be compensated for the error of the reference plane occurs when the measured object (O) bent.

For example, the surface shape measurement method according to the present invention for compensating for an error occurring when the measurement object O is bent will be described with reference to FIG. 3. Here, it is assumed that the measurement object O is a PCB substrate having a thin and wide plate shape, for example. In addition, the moire system is a PCB substrate having a plate area such that the entire surface of the PCB substrate cannot be measured by one shot. Therefore, the moire system allows the PCB substrate to have a plurality of measurement areas A1, A2, A3,. It is assumed that each of the measurement areas A1, A2, A3, ...., An is sequentially measured.

First, the surface of the PCB substrate is installed so as to match the sample reference plane R1 among the sample reference planes R1, R2, R3, R4, and R5 of the moire system. At this time, the PCB substrate is supported at both edges and installed in the moiré system, and the PCB substrate is bent by its own load so that the surface of the PCB substrate, that is, the actual reference plane RP, does not partially coincide with the sample reference plane R1. do. 3 is a diagram illustrating a relationship between a cross section of a portion of the PCB substrate and the sample reference planes R1, R2, R3, R4, and R5.

For example, when the area A3 is measured among the measurement areas A1, A2, A3, ...., An, the actual reference plane RP of the PCB substrate located on the area A3 is not the sample reference plane R1 but the sample reference plane. It can be seen that it is located closer to R2. In this case, when the reference phase for the specimen reference plane R1 is applied to Equation 12, the solder paste on the PCB substrate located between the actual reference plane RP in the A3 region and the specimen reference plane R1 is measured as being recessed from the PCB substrate, or The measurement itself may not be made outside the measurement range for reference plane R1.

Therefore, in the case of measuring the area A3, the displacement measuring device measures the displacement of the sample reference plane R1 in the area A3, that is, the actual reference plane RP of the PCB substrate in the area A3, and the information on the measured actual reference plane RP. Therefore, in the area A3, the surface shape is measured using the reference phase for the sample reference plane R2. Here, each sample reference plane (R1, R2, R3, R4, R5) has a predetermined distance range from the imaging device 20, the actual reference plane (RP) of the measurement object (O) is located within the distance The corresponding sample reference planes (R1, R2, R3, R4, R5) are applied. For example, as shown in FIG. 3, the sample reference plane R2 has a separation distance range HL, and when the actual reference plane RP is located between the separation distance H and the separation distance L, corresponding measurement areas A1, A2, A3,. ..., An) is applied to the measurement of surface shape.

Here, for the other measurement areas A1, A2, A3, ...., An, the actual reference plane RP is detected by the same method as described above, and the sample corresponding to the detected actual reference plane RP. The surface shape of each measurement area A1, A2, A3, ..., An is measured by using reference phases with respect to the reference planes R1, R2, R3, R4, and R5.

Hereinafter, in the surface shape measuring method according to the present invention, a method of calculating reference phase data for each sample reference plane (R1, R2, R3, R4, R5) will be described.

A method of calculating reference phase data for each point of each sample reference plane R1, R2, R3, R4, and R5 according to the first embodiment of the present invention will be described with reference to FIG. Reference surface measurement objects RO1, RO2, RO3, RO4, and RO5, which can be positioned at the above-described distances from the imaging device 20, respectively, correspond to R2, R3, R4, and R5. When each reference plane measurement (RO1, RO2, RO3, RO4, RO5) is installed in the moiré system, the distance from the surface of each reference plane measurement (RO1, RO2, RO3, RO4, RO5) to the imaging lens 21 is Corresponds to the L _C values for each sample reference plane R1, R2, R3, R4, R5.

Then, the reference plane measurements (RO1, RO2, RO3, RO4, RO5) are sequentially installed in the moiré system to calculate the phase data for the surface of each reference plane measurement (RO1, RO2, RO3, RO4, RO5). The phase data of the calculated surface of each reference plane measurement object (RO1, RO2, RO3, RO4, RO5) is stored in the memory as reference phase data of each corresponding reference plane (R1, R2, R3, R4, R5). .

이라 하고, 식 14와 같이 표시한다.A method of calculating reference phase data for each sample reference plane (R1, R2, R3, R4, R5) according to a second embodiment of the present invention will be described with reference to FIG. 5, according to the first embodiment of the present invention. Unlike the calculation method of the reference phase data, only the reference plane measurement object RO corresponding to any one of the sample reference planes R1, R2, R3, R4, and R5, for example, the sample reference plane R1, is prepared. Then, the reference plane measurement object RO1 corresponding to the sample reference plane R1 is installed in the moire system to calculate the reference phase data for the sample reference plane R1 as in the first embodiment. Here, the reference phase for the sample reference plane R1 is calculated through Equation 10, and the reference phase for the sample reference plane R1 is calculated according to the sample reference phase.

This is represented by Equation 14.

[Equation 14]

는 식 15와 같이 표현될 수 있다.Then, the remaining sample reference planes (R2, R3, R4, R5) are calculated based on the reference phase data for the sample reference plane R1 and the reference phase data for the sample reference plane R1. As shown in FIG. 5, the incident angle at which light from the projector 10 is incident on each of the sample reference planes R1, R2, R3, R4, and R5 is called θ, and the distance between the sample reference plane R1 and the sample reference plane R2 is If δh, reference phase with respect to sample reference plane R2

Can be expressed as shown in Equation 15.

[Equation 15]

는 식 13 및 식 14에 기초해서, 식 16과 같이 기재될 수 있다.Where the reference phase

Can be described as in Equation 16 based on Equations 13 and 14.

[Equation 16]

Reference phase data for the sample reference planes R3, R4, R5, ....., Rn can also be calculated in the same way.

In the above embodiment, the surface shape measurement method according to the phase measurement profile (PMP: Phase Measurement Profilometry) has been described as an example, but the technical concept of the present invention is applicable to the moire method using the reference plane (RP). .

As such, calculating and storing reference phase data for the plurality of sample reference planes R1, R2, R3, R4, and R5 having different separation distances from the imaging device 20, and the imaging device 20 and the measured object. Detecting a separation distance between the actual reference planes (RP) of (O), calculating measurement phase data on the surface of the workpiece (O) using a moiré system, and detecting the actual reference planes detected among the reference phase data. Calculating data on the surface shape of the workpiece O based on the reference phase data and the measurement phase data corresponding to the separation distance of RP, thereby collecting the workpiece O by a specific reference plane ( Error in the installation of RP) or reference phase RP relative to the reference plane RP caused by the warp of the workpiece O even if the measurement object O is correctly installed on the specific reference plane RP of the moire system. Error in surface profile measurement Being able to be compensated, it is possible to implement a system with less moiré than moiré system with a conventional error compensation method.

As described above, according to the present invention, there is provided a surface shape measurement method that enables more accurate surface shape measurement by using reference phases for a plurality of reference planes and lowers the price of the moire system.

Claims (6)

Method of measuring the surface shape using a moiré system having a projection device having a projection grid and a light source for projecting light onto the workpiece through the projection grid, and an imaging device for forming a grid image formed by the light projected on the workpiece To Calculating a plurality of reference phase data for a plurality of sample reference planes having different separation distances from the imaging device; Detecting a separation distance between the imaging device and the actual reference plane on which the workpiece is placed; Calculating measurement phase data of the surface of the workpiece using the moiré system; Calculating data on the surface shape of the workpiece based on reference phase data and the measured phase data corresponding to the detected separation distance of the actual reference plane among the plurality of reference phase data; Shape measuring method. The method of claim 1, Computing the plurality of reference phase data for the plurality of sample reference planes, Providing a plurality of reference plane workpieces that can be positioned at different distances from the imaging device in correspondence with each of the specimen reference planes; Calculating reference phase data for the surface of each reference plane workpiece using the moiré system; And storing the calculated reference phase data for the surface of each reference plane workpiece as the reference phase data for each corresponding sample reference plane. The method of claim 1, Computing the plurality of reference phase data for the plurality of sample reference planes, Providing a sample reference plane measurement object which can be positioned from the imaging device at a distance corresponding to at least one sample reference plane of the plurality of sample reference planes; Calculating sample reference phase data on the surface of the sample reference plane measurement using the moiré system; Storing the calculated sample reference phase data as the reference phase data for the corresponding sample reference plane; Calculating and storing deviation information between the remaining sample reference plane and the sample reference plane corresponding to the sample reference phase data and the reference phase data for the remaining sample reference plane based on the sample reference phase data. Surface shape measurement method characterized in that. The method of claim 3, wherein The deviation information includes information on a separation distance δ _h between the remaining sample reference plane and the sample reference plane corresponding to the sample reference plane; The reference phase data for the remaining sample reference planes is

(here,

Is the reference phase for the remaining sample reference planes,

Is the sample reference phase, g is the lattice spacing of the projection lattice, L _P is the separation distance between the light source and the sample reference plane corresponding to the sample reference phase, f _P is the separation distance between the light source and the projection lattice, d Is a separation distance between the optical axis of the projection device and the optical axis of the imaging device). The method of claim 3, wherein The deviation information includes information on the separation distance δ _h between the remaining sample reference plane and the sample reference plane corresponding to the sample reference plane, The reference phase data for the remaining sample reference planes is

(here,

Is a reference phase with respect to the remaining sample reference plane, g is a lattice spacing of the projection lattice, f _P is a separation distance between the light source and the projection lattice, d is a separation distance between the optical axis of the projection apparatus and the optical axis of the imaging device, L _P is the separation distance between the light source and the sample reference plane corresponding to the sample reference phase, L _C is the separation distance between the imaging lens of the imaging device and the sample reference plane corresponding to the sample reference phase, f _C is the imaging lens And the separation distance between the light receiving surface of the imaging device, x _i is the distance between the optical axis of the projection device and a point on the sample reference plane corresponding to the sample reference phase, Δ is the initial position of the projection lattice) Surface shape measurement method characterized in that. In the method of measuring the surface shape of the substrate on which the solder paste is formed, Partitioning the substrate into a plurality of measurement regions; Calculating data for the surface shape of the substrate on each measurement area by using the surface shape measurement method according to any one of claims 1 to 4 for each measurement area; And displaying the surface shape of the substrate based on data on the surface shape of the substrate on each measurement area.

Images