TWI685639B - Shape measuring device and coating device equipped with the device - Google Patents

Abstract

The control device 6 of the shape measuring device controls the piezoelectric table 5 and the imaging device 4, while moving the interferometer 3 in the optical axis direction, while taking various images at a plurality of positions h, the brightness distribution of the pixels of each image , The degree of separation R is obtained according to the discriminant analysis method, and then the piezoelectric table 5 is arranged at a position hf corresponding to the image in which the degree of separation R in the plurality of images becomes the maximum value Rmax, whereby the focus P1 of the interferometer 3 Arranged on the surface of the object 7. Therefore, the focus P1 of the interferometer 3 can be easily aligned with the surface of the object 7.

Description

Shape measuring device and coating device equipped with the device

The present invention relates to a shape measuring device and a coating device equipped with the device, and particularly relates to a shape measuring device that uses an interferometer to measure the surface shape of an object. More specifically, it relates to a shape measuring device that measures the surface shape of metals, resins, those processed products, etc., or the surface shape of substrates of semiconductor devices, electronic circuits, flat panel displays, and the like.

Japanese Unexamined Patent Publication No. 2000-56210 (Patent Document 1) discloses an autofocus device that uses a Z stage to move a CCD camera to an object, and at the same time shoots various images at a plurality of positions, and then Calculate the differential value of the brightness of a plurality of pixels included in each image (hereinafter, sometimes referred to as the differential value of the image), and arrange the CCD camera at the position corresponding to the image whose differential value becomes the largest, by which the CCD The focus of the camera is on the object.

【Advanced Patent Literature】 【Patent Literature】

[Patent Document 1] Japanese Patent Laid-Open No. 2000-56210

The differential value of the image becomes a large value where, for example, the light and dark patterns change rapidly as the boundary between the object and the background. Compared with the image taken in the unfocused state, the image captured in the focused state has a clear boundary between the object and the background, and the differential value of the image becomes larger. Therefore, by arranging the CCD camera at the position where the differential value of the image becomes the maximum, the focus of the CCD camera can be focused on the object.

However, in a shape measuring device that uses an interferometer to measure the surface shape of an object, the measurement is generally started after focusing the interferometer on the surface of the object. As the reference surface of the object, a flat portion such as the upper end surface of the object or a vertex portion of the spherical surface is often selected. On this reference plane, the changes in shape and light-dark pattern are alleviated, and the changes in light and dark of interference fringes are also alleviated, and the differential value of the image of interference fringes is small. Therefore, as shown in Patent Document 1, it is difficult to align the focus of the interferometer to the reference plane using only the differential value of the image of the interference fringe. In addition, in the conventional technology (Patent Document 1), a pattern to be a target is required for focusing, and if there is no target, defects may occur in the focusing operation.

Therefore, the main object of the present invention is to provide a shape measuring device that can easily align the focus of the interferometer to the surface of the object.

The shape measuring device of the present invention is a shape measuring device for measuring the surface shape of an object, which includes an interferometer, which separates the white light emitted from the lighting device into first and second light beams, and irradiates the first light beam onto the The surface of the object and the second beam is irradiated to the reference surface, and then the reflected light from the surface of the object is combined with the reflected light from the reference surface to produce interference fringes corresponding to the surface shape of the object; the observation optical system is used To observe interference fringes; camera equipment The first positioning device is to relatively move the object and the interferometer in the optical axis direction; and the control device is to control the imaging device and the first positioning device to perform interference. The focus of the meter is on the first autofocusing action on the surface of the object. The control device moves the object and the interferometer relative to each other in the optical axis direction during the first auto-focusing operation, while shooting each image at a plurality of relative positions, and the brightness of the plurality of pixels included in the image in each image In the distribution map, the degree of separation is determined according to the discriminant analysis method, and then the object and the interferometer are arranged at relative positions corresponding to the images having the largest degree of separation among the plurality of images.

In the shape measuring device of the present invention, the brightness distribution of a plurality of pixels included in the image in each image is determined according to the discriminant analysis method, and then the object and the interferometer are arranged in the plurality of images The degree of separation becomes the relative position corresponding to the image, whereby the focus of the interferometer is aligned with the surface of the object. Therefore, the focus of the interferometer can be easily aligned with the surface of the object. In addition, since the focus of the interferometer can be easily and surely aligned on the surface of the object, the defect of the work performed after the focus is achieved does not occur, and the work efficiency can be improved. Furthermore, the total working time including the processing of the present invention can be shortened, and the manufacturing cost of the product can be reduced.

1‧‧‧Lighting

2‧‧‧Observation optical system

2a‧‧‧ Observation tube

3‧‧‧Mirau interferometer

4‧‧‧Camera device

5‧‧‧ Piezo worktable

6‧‧‧Control device

7‧‧‧Object,

8‧‧‧Laser device for cutting

9‧‧‧ substrate

10‧‧‧Head

11‧‧‧White light source

12‧‧‧ filter

15‧‧‧movable plate

15a‧‧‧Through hole

17‧‧‧Coating unit

19.31‧‧‧Objective

20‧‧‧Light source for ink hardening

21‧‧‧Condenser

22‧‧‧Half mirror

23‧‧‧Imaging lens

32‧‧‧Reflecting mirror

33‧‧‧Semi-transmissive mirror

40‧‧‧Z Workbench

42‧‧‧X Workbench

44‧‧‧Y Workbench

50‧‧‧Ink coating mechanism

70‧‧‧Control computer

72‧‧‧Operation panel

74‧‧‧Monitor

91‧‧‧Metal film

92‧‧‧Coating Department

94‧‧‧Ink

100‧‧‧coating device

170‧‧‧Coating needle

172‧‧‧Ink tank

A1~A3‧‧‧ Optical axis

Fig. 1 is a block diagram showing the configuration of the shape measuring apparatus according to the first embodiment of the present invention.

Figure 2 shows the configuration of the shape measuring device shown in Figure 1 in more detail Figure.

FIG. 3 is a diagram showing the configuration and operation of the Milau interferometer shown in FIG. 2.

Figure 4 is the brightness distribution of the image of the interference fringe generated by the Milau interferometer shown in Figure 3.

FIG. 5 is a diagram showing the relationship between the position of the piezoelectric table shown in FIG. 1 and the degree of image separation.

FIG. 6 is a diagram illustrating an example of the autofocus operation of the shape measuring device shown in FIGS. 1 to 5.

Fig. 7 is a block diagram showing the configuration of a shape measuring device according to a second embodiment of the present invention.

FIG. 8 is a diagram showing an example of the autofocus operation of the shape measuring device shown in FIG. 7.

Fig. 9 is a perspective view showing the overall configuration of a coating device equipped with a shape measuring device according to this embodiment.

Fig. 10 is a perspective view showing the main part of the observation optical system and the ink application mechanism.

FIG. 11 is a view of the main part viewed from the direction A of FIG. 10.

Fig. 12 is a first diagram for explaining the ink application operation.

Fig. 13 is a second diagram for explaining the ink application operation.

Fig. 14 is a third diagram for explaining the ink application operation.

Fig. 15 is a fourth diagram for explaining the ink application operation.

Fig. 16 is a fifth diagram for explaining the ink application operation.

FIG. 17 is a diagram for explaining the method of inspecting the film thickness.

FIG. 18 is a flowchart for explaining the film thickness inspection process.

[First Embodiment]

Fig. 1 is a block diagram showing the configuration of the shape measuring apparatus according to the first embodiment of the present invention. In FIG. 1, the shape measuring device includes a head 10, which is composed of an illumination device 1, an observation optical system 2, a Milau interferometer 3, an imaging device 4, and a piezoelectric table (first positioning device) 5; And control device 6. The lighting device 1 outputs white light. The observation optical system 2 reflects the white light output from the lighting device 1 and supplies it to the Mirau interferometer 3, and is used to observe the interference fringes generated by the Mirau interferometer 3.

The Milau interferometer 3 separates the white light incident from the illumination device 1 through the observation optical system 2 into first and second light beams, irradiates the first light beam on the surface of the object 7 and irradiates the second light beam On the reference surface, the reflected light from the surface of the object 7 interferes with the reflected light from the reference surface, and interference fringes are generated. The imaging device 4 is controlled by the control device 6 and takes an image of the interference fringe generated by the Milau interferometer 3 via the observation optical system 2. Each image captured by the camera device 4 is stored in the control device 6. The piezoelectric table 5 is controlled by the control device 6 and moves the Milau interferometer 3 to the object 7 in the optical axis direction (vertical direction).

The control device 6 controls the entire shape measuring device. In particular, the control device 6 controls the imaging device 4 and the piezoelectric table 5, while moving the Milau interferometer 3 to the object 7 in the direction of the optical axis, while shooting each image at a plurality of positions, and then according to the plurality of images The focus of the Milau interferometer 3 is on the autofocus operation (first autofocus operation) on the surface of the object 7. About automatic pairing The focus operation will be described in detail later.

FIG. 2 is a diagram showing the configuration of the shape measuring device shown in FIG. 1 in more detail, and FIG. 3 is a diagram showing the configuration and operation of the Milau interferometer 3. In FIGS. 2 and 3, the illumination device 1 is arranged on the side of the observation optical system 2 and includes a white light source 11 and a filter 12. The optical axis A1 of the illumination device 1 (that is, the optical axis of the white light source 11) is arranged in the horizontal direction and is orthogonal to the optical axis A2 of the observation optical system 2. The white light source 11 emits white light. The filter 12 is arranged between the white light source 11 and the observation optical system 2 and passes white light having a predetermined center wavelength λ0 and wavelength range Δλ among the white light emitted from the white light source 11.

The observation optical system 2 includes a condenser lens 21, a half mirror 22, and an imaging lens 23. The optical axis A2 of the observation optical system 2 (that is, the optical axis of the imaging lens 23) is arranged in the vertical direction. The condenser 21 is disposed between the filter 12 and the half mirror 22, and converts the white light emitted from the white light source 11 and passing through the filter 12 into parallel light.

The half mirror 22 is arranged at the intersection of the two optical axes A1 and A2, and is arranged at an angle of 45 degrees to each of the two optical axes A1 and A2. The Milau interferometer 3 is arranged below the half mirror 22, and the imaging lens 23 and the imaging device 4 are arranged above the half mirror 22. The half mirror 22 reflects the white light incident from the illumination device 1 through the condenser 21 to the lower side, and passes the light from the Milau interferometer 3 (that is, the image of the interference fringe) to the upper side. The imaging lens 23 is a light sensor that images the light from the Milau interferometer 3 on the imaging device 4.

The Milau interferometer 3 is installed at the lower end of the observation optical system 2 via the piezoelectric table 5, and includes an objective lens 31, a reflection mirror 32, and a semi-transmissive mirror 33. The optical axis A3 of the Milau interferometer 3 (that is, the optical axis of the objective lens 31) coincides with the optical axis A2 of the observation optical system 2. The piezoelectric table 5 moves the Milau interferometer 3 in the direction of the optical axis A3. As shown in FIGS. 2 and 3, the object 7-based substrate, the optical axis A3 is vertically arranged on the surface of the substrate, and the focal point P1 of the Milau interferometer 3 (that is, the focal point of the objective lens 31) is arranged on the surface of the substrate status.

The reflection mirror 32 has its reflection surface (reference surface) facing down, and is fixed to the center of the lower surface of the objective lens 31. The semi-transmissive mirror 33 is arranged between the reflection surface of the mirror 32 and the focal point P1. Each of the mirror 32 and the semi-transmissive mirror 33 is orthogonal to the optical axis A3.

The white light L0 emitted from the illumination device 1 and incident on the Milau interferometer 3 through the observation optical system 2 is refracted by the objective lens 31 as shown in FIG. 3 to the focus P1. A part of the white light L0 passes through one end of the semi-transmissive mirror 33 to become the first light beam L1, and the remaining part of the white light L0 is reflected at one end of the semi-transmissive mirror 33 to become the second light beam L2. That is, the white light L0 is separated into the first and second light beams L1, L2 by the semi-transmissive mirror 33.

The first light beam L1 is reflected on the surface of the object 7 as the first reflected light L1r, and goes to the other end of the semi-transmissive mirror 33. The second light beam L2 is reflected on the reflecting surface of the reflecting mirror 32, becomes the second reflected light L2r, and goes to the other end of the semi-transmitting mirror 33. The first and second reflected lights L1r and L2r merge at the other end of the semi-transmissive mirror 33, interfere with each other, and become interference light L3.

When the phase difference between the two reflected lights L1r and L2r is 0 degrees, the amplitude of the interference light L3 becomes the maximum, and the brightness of the interference light L3 becomes the maximum. When the phase difference between the two reflected lights L1r and L2r is 180 degrees, the amplitude of the interference light L3 becomes the smallest, and the brightness of the interference light L3 becomes the smallest. With the first beam L1 in focus The Milau interferometer 3 is designed such that the difference in the optical path lengths of the reflected lights L1r and L2r becomes zero when reflected at the point P1.

Therefore, when the focus P1 of the Milau interferometer 3 coincides with the surface of the object 7 (that is, when it is in focus), the phase difference of the reflected light L1r and L2r and the difference in the optical path length become 0, and the interference light L3 becomes the brightest As the distance between the focal point P1 and the surface of the object 7 becomes longer, the interference light L3 becomes darker. At the half mirror 33, interference fringes corresponding to the surface shape of the object 7 appear. Based on this interference fringe, the surface shape of the object 7 can be measured.

In order to obtain clear interference fringes, it is necessary to make the focal point P1 of the Milau interferometer 3 coincide with the surface of the object 7. In the following, an auto-focusing operation for matching the focus P1 of the Milau interferometer 3 with the surface of the object 7 will be described.

The control device 6 controls the imaging device 4 and the piezoelectric table 5 during the autofocus operation, and while moving the Milau interferometer 3 in the direction of the optical axis A3, shoots a plurality of images at a plurality of positions. The brightness distribution maps of the plurality of images taken are produced, and the separation value R is obtained for each brightness distribution map by discriminant analysis, and the Milau interferometer 3 is arranged at the position where the separation value R becomes the largest.

Figure 4 is the brightness distribution of the image of an interference fringe. The image contains a plurality of pixels arranged in a plurality of columns and rows. Each pixel displays the brightness of one of a plurality of stages (for example, 256 stages) of luminance. The horizontal axis of Fig. 4 represents the brightness of plural stages, and the vertical axis represents the number of pixels displaying each brightness. When the focal point P1 of the Milau interferometer 3 is brought close to the surface of the object 7, as shown in FIG. 4, the brightness distribution diagram shows bimodality.

In the discriminant analysis method, the brightness distribution map of the image is divided into two levels CL1 and CL2 by the brightness threshold Lth. The level CL1 is a group of pixels whose luminance is smaller than the luminance threshold Lth. The level CL2 is a group of pixels whose luminance is greater than the luminance threshold Lth. The brightness threshold Lth is set such that the intra-level dispersion σ _W ² becomes the smallest, and the inter-level dispersion σ _B ² becomes the maximum, and the ratio of the inter-level dispersion σ _B ² to the intra-level dispersion σ _W ² σ _B ² /σ _W ² as the resolution R.

The intra-level dispersion σ _W ² is the degree of expansion of the distribution graph within the level, and the inter-level dispersion σ _B ² is the degree of expansion between the two levels CL1 and CL2. The intra-level dispersion σ _W ² and the inter-level dispersion σ _B ² are expressed by mathematical formulas (1) and (2), respectively.

σ _W ² =(n ₁ ×σ ₁ ² +n ₂ ×σ ₂ ² )/(n ₁ +n ₂ )...(1)

σ _B ² = (n ₁ (μ ₁ -μ ₀ ) ² +n ₂ (μ ₂ -μ ₀ ) ² )/(n ₁ +n ₂ )...(2)

Among them, σ ₁ ² and σ ₂ ² are the dispersion of brightness in the levels CL1 and CL2 respectively, μ ₀ is the average value of the brightness of all pixels, μ ₁ and μ ₂ are the average value of the brightness in the levels CL1 and CL2, n ₁ and n ₂ are the number of pixels in levels CL1 and CL2, respectively.

FIG. 5 is a diagram exemplifying the relationship between the position h of the piezoelectric table 5 and the degree of separation R. FIG. Fig. 5 shows that while changing the position h of the piezoelectric table 5 (coordinates in the height direction of the movable part of the piezoelectric table 5) from 0 μm to 20 μm, multiple images are taken while generating the brightness distribution map of each pixel , And find the degree of separation R of each brightness profile. In Figure 5, the resolution R system rises from 0 at the time point of h≒7.5μm, and becomes the maximum value (about 0.105) at the time point of h≒9.2μm, then decreases, and becomes at the time point of h≒10.7μm. 0. By arranging the piezoelectric table 5 at the position (h≒9.2 μm) when the degree of separation R becomes the maximum value (about 0.105), the focal point P1 of the Milau interferometer 3 can be matched with the surface of the object 7.

Secondly, the auto focus of the shape measuring device will be specifically explained action. The control device 6 controls the imaging device 4 and the piezoelectric table 5 during the autofocus operation, while moving the Milau interferometer 3 in the direction of the optical axis A3 at a fixed speed V1, while shooting various images at a plurality of positions h . If the image capturing period of the camera 4 is taken as T1 (seconds) and the center wavelength of the white light emitted from the lighting device 1 is taken as λ0 (μm), then the moving speed V1 of the Milau interferometer 3 is set During the taking-in period T1 (seconds), the Milau interferometer 3 moves only by λ0/8 (μm). The initial moving direction of the Milau interferometer 3 is regarded as one of the direction in which the Milau interferometer 3 approaches the object 7 and the direction away from it.

Between moving the Milau interferometer 3 at a fixed speed V1 by the piezoelectric table 5, the control device 6 takes in images from the imaging device 4 at a predetermined period T1 (seconds). The control device 6 calculates the degree of separation R of the image every time the capturing of the image is completed, and obtains the position hf of the piezoelectric table 5 when the image with the maximum degree of separation R is captured. Finally, the control device 6 sets the position h of the piezoelectric table 5 to the position hf at the time when the image at which the degree of separation R is maximized is captured, and the autofocus operation ends.

In detail, when the driving speed of the piezoelectric table 5 reaches a fixed speed V1, the control device 6 calculates the separation R of the image while taking the image from the imaging device 4 at T1 (second) intervals, and takes When the position h of the piezoelectric table 5 at the time of image input is associated, the degree of separation R is stored in the memory portion (not shown).

After memorizing the separation R and position h of a complex array (for example, 3 groups), as shown in (a) and (b) of FIG. 6, plot the position h and the separation axis R on the vertical axis, and draw Approximate straight line connecting multiple points. In FIG. 6(a), the piezoelectric table 5 can move from the position h1 to the position h2, and shows the state in which the piezoelectric table 5 moves in the direction from h2 to h1.

For example, as shown in FIG. 6(a), when the separation value R in the moving direction of the position h of the piezoelectric table 5 decreases, and the piezoelectric table 5 is once stopped, as shown in FIG. 6(b) , The piezoelectric table 5 is moved in the opposite direction, and the piezoelectric table 5 is moved to the position h to become h2 while taking images at a predetermined period T1 (seconds). At the beginning, when the moving direction separation value R of the position h of the piezoelectric table 5 increases, the image is captured at a predetermined period T1 (second) while moving the piezoelectric table 5 to the position h to be h1.

While taking in the image, the degree of separation R of the image is obtained, and the position hf of the piezoelectric table 5 corresponding to the image where the degree of separation R becomes the maximum value Rmax is obtained. That is, after memorizing the separation R and the position h of a complex array (for example, 8 groups), the maximum value Rmax of the plurality of separation values R is obtained. Next, the absolute value of the difference between the maximum value Rmax and the separation value Rs of the first group △Rs=|Rmax-Rs|, and the absolute value of the difference between the maximum value Rmax and the separation value Re of the last group △Re=| Rmax-Re|, when both △Rs and △Re are greater than the predetermined threshold Rth, the position hf of the piezoelectric table 5 corresponding to the image where the separation R becomes the maximum value Rmax is obtained, and the piezoelectric is operated The table 5 moves to this position hf. At this time, the position of the focal point P1 of the Milau interferometer 3 coincides with the surface of the object 7.

When at least one of ΔRs and ΔRe is smaller than the threshold Rth, the search is continued until the position of the piezoelectric table reaches h1 or h2. When h1 or h2 cannot be detected and △Rs and △Re both become Rmax greater than the predetermined threshold Rth, the piezoelectric table 5 is returned to the search start position, and the search continues until the piezoelectric table is in the opposite direction The location reaches h1 or h2. Between h1 and h2, when it cannot be detected that both △Rs and △Re become Rmax greater than the predetermined threshold Rth As if the autofocus action failed, and ended.

Specifically, in Fig. 6(a), the image is taken from the position of N=1, after the image is taken from the position of N=3, an approximate straight line connecting 3 points is obtained, and the approximate straight line to the moving direction is determined The slope is negative, as shown in Figure 6(b), the search starts in the opposite direction. In the search in the opposite direction, the image is taken from the position of M=1, after the image is taken at the position of M=8, the peak value judgment is started, and the separation R at the position of M=5 is determined to be the maximum value Rmax, and It is judged that both ΔRs and ΔRe are greater than the threshold value Rth, the piezoelectric table 5 is arranged at a position hf corresponding to M=5, and the focus P1 of the Milau interferometer 3 is aligned with the surface of the object 7 .

As described above, in the first embodiment, the piezoelectric table 5 and the imaging device 4 are controlled to move the Milau interferometer 3 in the direction of the optical axis, while shooting each image at a plurality of positions h, and then to each The brightness distribution of the pixels of the image, the resolution R is obtained by discriminant analysis, and then the position h of the piezoelectric table 5 is arranged at a position hf corresponding to the image where the separation R of the plurality of images becomes the maximum value Rmax As a result, the focal point P1 of the Milau interferometer 3 is arranged on the surface of the object 7. Therefore, the focus P1 of the Milau interferometer 3 can be easily aligned with the surface of the object 7 and the work efficiency can be improved.

In addition, in the first embodiment, the object 7 is fixed and the Milau interferometer 3 is moved by the piezoelectric table 5, but it is not limited to this, as long as the object 7 and the Milau interferometer 3 are relatively moved Alternatively, it can be moved by any method. For example, the Milau interferometer 3 may be fixed and the object 7 may be moved, or both the Milau interferometer 3 and the target 7 may be moved in opposite directions.

In addition, in the first embodiment, the use of the Milau interferometer 3 However, other types of interferometers can also be used. For example, a Michelson interferometer or Linnik type interferometer can also be used.

[Second Embodiment]

Fig. 7 is a block diagram showing the configuration of a shape measuring device according to a second embodiment of the present invention, and is a diagram compared with Fig. 1. Referring to FIG. 7, a Z table (second positioning device) 40 is added to the difference between this shape measuring device and the shape measuring device of FIG. 1. The illumination device 1, the observation optical system 2, the Milau interferometer 3, the imaging device 4, and the piezoelectric table 5 constitute one optical unit, and this optical unit is mounted on the Z table 40. The Z table 40 is controlled by the control device 6 to move the optical unit in the height direction.

The stroke of the Z table 40 is longer than that of the piezoelectric table 5. In the first embodiment, while moving the Milau interferometer 3 by the piezoelectric table 5 only, a plurality of images are taken, and then the focus is made according to the separation R of the plurality of images taken (the first autofocus operation), However, in the second embodiment, before the first autofocus operation is performed, a plurality of images are taken while the Milau interferometer 3 is moved by the Z table 40, and then the focus point is based on the differential value D of the plurality of images taken. Perform coarse adjustment of the position (2nd AF operation). This is effective when the piezoelectric table 5 cannot be in focus during the stroke.

Next, the second AF operation in this measurement will be specifically described. The control device 6 controls the imaging device 4 and the Z table 40 during the second autofocus operation, while moving the Milau interferometer 3 in the direction of the optical axis A3 at a fixed speed V2, and at the same time shooting each of them at a plurality of positions H image. The moving speed V2 of the Z table 40 is faster than the moving speed V1 of the piezoelectric table 5. The initial movement direction of the Milau interferometer 3 is regarded as the approach of the Milau interferometer 3 to the object 7 One of the direction and the direction away from.

During the movement of the Milau interferometer 3 at a fixed speed V2 by the Z table 40, the control device 6 takes in images from the imaging device 4 at a predetermined period T2 (seconds). The control device 6 calculates the differential value D of the image every time the image capturing is completed, and obtains the position Hf of the Z table 40 (the height of the movable part of the Z table 40) when the image with the maximum differential value D is captured Direction coordinates). Finally, the control device 6 sets the position H of the Z table 40 to the position Hf when the image where the differential value D is maximized is captured, and the second autofocus operation ends. The differential value D of the image is expressed by mathematical formulas (3), (4), and (5).

Among them, F represents the taken image, (x, y) represents the position of the pixel of the image F, dx represents the differential value in the horizontal direction, and dy represents the differential value in the vertical direction.

In detail, when the driving speed of the Z table 40 reaches a fixed speed V2, the control device 6 calculates the differential value D of the image from the side where the image is taken in by the camera device 4 at T2 (second) intervals, and the The position H of the Z stage 40 at the time of imaging is correlated, and the differential value D is stored in the memory (not shown).

After memorizing the differential value D and position H of a complex array (for example, 3 groups), as shown in (a) and (b) of FIG. 8, plot the horizontal axis to indicate the position H and the vertical axis to indicate the differential value D, and draw Approximate straight line connecting multiple points. In FIG. 8(a), the Z table 40 can move from the position H1 to the position H2, and shows the state in which the Z table 40 moves in the direction from H2 to H1.

For example, as shown in FIG. 8(a), when the differential value D in the moving direction of the position H of the Z table 40 decreases, after stopping the Z table 40 once, as shown in FIG. 8(b), make The Z table 40 is moved in the opposite direction, and the Z table 40 is moved to the position H to become H2 while taking images at a predetermined period T2 (seconds). At the beginning, when the differential value D of the moving direction of the position H of the Z table 40 increases, the image is captured at a predetermined period T2 (second) while moving the Z table 40 to the position H to become H1.

While taking in the image, the differential value D of the image is obtained, and the position Hf of the Z table 40 corresponding to the image whose differential value D becomes the maximum value Dmax is obtained. That is, after memorizing the differential value D and the position H of a complex array (for example, 8 sets), the maximum value Dmax among the plurality of differential values D is obtained. Next, the absolute value ΔDs=|Dmax-Ds| of the difference between the maximum value Dmax and the differential value Ds of the first group, and the absolute value ΔDe=| of the difference between the maximum value Dmax and the differential value De of the last group Dmax-De|, when both △Ds and △De are greater than the predetermined threshold Dth, find the position Hf of the Z table 40 corresponding to the image where the differential value D becomes the maximum value Dmax, and make the Z table 40 Move to this position Hf. At this time, the position of the focal point P1 of the Milau interferometer 3 substantially coincides with the surface of the object 7.

When at least one of ΔDs and ΔDe is smaller than the threshold Dth, the search is continued until the position of the Z table reaches H1 or H2. When H1 or H2 is reached, it cannot be detected that both △Ds and △De become larger than the predetermined threshold Dth At Dmax, the Z table 40 is returned to the search start position, and the search is continued in the opposite direction until the position of the Z table reaches H1 or H2. Between H1 and H2, when it is impossible to detect that both △Ds and △De become Dmax greater than the predetermined threshold Dth, it is regarded as the failure of the autofocus operation and ends.

Then, the Z table 40 is fixed to the position Hf corresponding to the image where the differential value D becomes the maximum value Dmax, and then the focus of the Milau interferometer 3 is made according to the method described in the first embodiment (first autofocus operation). P1 precisely matches the surface of the object 7.

Specifically, in Fig. 8(a), the image is taken from the position of N=1, after the image is taken from the position of N=3, an approximate straight line connecting 3 points is obtained, and the approximate straight line to the moving direction is determined The slope is negative, as shown in Figure 8(b), the search starts in the opposite direction. In the search in the opposite direction, the image is taken from the position of M=1, after the image is taken at the position of M=8, the peak value judgment is started, and the differential value D at the position of M=5 is determined to be the maximum value Dmax, and It is determined that both ΔDs and ΔDe are greater than the threshold value Dth, and the Z table 40 is arranged at a position Hf corresponding to M=5, so that the focal point P1 of the Milau interferometer 3 and the surface of the object 7 substantially coincide.

As described above, in the second embodiment, before focusing on the method according to the method of the first embodiment (first autofocus operation), the Z table 40 and the imaging device 4 are controlled so that the Milau interferometer 3 is Moving in the optical axis direction, while shooting each image at a plurality of positions H, the differential value D of each image is obtained, and then the Z table 40 is arranged to correspond to the image where the differential value D among the plurality of images becomes the maximum value Dmax The position Hf of this makes the focal point P1 of the Milau interferometer 3 substantially coincide with the surface of the object 7. Therefore, in borrowing only the piezoelectric table 5. When the focus P1 cannot be aligned, the focus P1 of the Milau interferometer 3 can be easily aligned with the surface of the object 7 and the work efficiency can be improved.

In addition, in the second embodiment, the object 7 is fixed and the Milau interferometer 3 is moved by the Z table 40, but it is not limited to this, as long as the object 7 and the Milau interferometer 3 are relatively moved. , Can be moved by any method. For example, the Milau interferometer 3 may be fixed and the object 7 may be moved, or both the Milau interferometer 3 and the target 7 may be moved in opposite directions.

In addition, in the second embodiment, the case of using the Milau interferometer 3 has been described, but it is not limited to this, and other types of interferometers may be used. For example, a Michelson interferometer or Linnik type interferometer can also be used.

[Configuration of coating device]

Finally, as an example of an apparatus to which the shape measuring apparatus according to this embodiment is applied, the outline of the coating apparatus will be described.

FIG. 9 is a perspective view showing the overall configuration of the coating device 100 including the shape measuring device according to this embodiment. The coating device 100 is configured to apply transparent ink (liquid material) to the main surface of the substrate 9 in multiple layers. Referring to FIG. 9, the coating device 100 includes a coating head, which is composed of an observation optical system 2, a CCD camera 4, a laser device for cutting 8, an ink coating mechanism 50, and a light source 20 for ink curing; Z The table 40 moves the coating head to the substrate 9 to be coated in the vertical direction (Z-axis direction); the X table 42 carries the Z table 40 and moves it in the X-axis direction; Y works The stage 44 mounts the substrate 9 and moves it in the Y-axis direction; the control computer 70 controls the overall operation of the device; the monitor 74 displays images captured by the CCD camera 4; and the operation panel 72 controls the system Used to input commands from the operator Making computer 70.

The observation optical system 2 includes a light source for illumination (illumination device 1 in FIG. 1), and observes the surface state of the substrate 9 or the state of ink applied by the ink application mechanism 50. The image observed by the observation optical system 2 is converted into an electrical signal by the CCD camera 4 and displayed on the monitor 74. The dicing laser device 8 irradiates and removes unnecessary parts on the substrate 9 through the observation optical system 2 by laser light.

The ink application mechanism 50 applies ink to the main surface of the substrate 9. The light source 20 for ink hardening contains, for example, CO ₂ laser, and irradiates the laser light on the ink applied by the ink application mechanism 50 to make it hard.

In addition, this device configuration is an example, and for example, it may be called an overhead configuration. This configuration is to mount the Z table 40 with the observation optical system 2 and the like on the X table, and then mount the X table on the Y table. The Z table 40 can be moved in the XY direction, as long as the Z table 40 equipped with the observation optical system 2 or the like can relatively move the target substrate 9 in the XY direction, any structure can be used.

Next, an example of the ink application mechanism 50 using a plurality of application needles will be described. FIG. 10 is a perspective view showing the main parts of the observation optical system 2 and the ink application mechanism 50. Referring to FIG. 10, the coating device 100 includes: a movable plate 15; a plurality of (for example, five) objective lenses 19 with different magnifications; and a plurality of (for example, five) coating units 17 for coating Ink composed of different materials.

The movable plate 15 is provided between the lower end of the observation lens barrel 2a of the observation optical system 2 and the substrate 9 so as to be movable in the X-axis direction and the Y-axis direction. In addition, for the movable plate 15, for example, five through holes 15a are formed.

The objective lens 19 is fixed to the lower surface of the movable plate 15 at predetermined intervals in the Y-axis direction so as to correspond to the through holes 15a. The five coating units 17 are arranged adjacent to the five objective lenses 19, respectively. By moving the movable plate 15, the desired coating unit 17 can be arranged above the target substrate 9.

Figures 11 (a) to (c) are views of the main part viewed from the direction A of Figure 10, and are diagrams showing the ink application operation. The coating unit 17 includes a coating needle 170 and an ink tank 172. As shown in FIG. 11(a), the coating needle 170 of the desired coating unit 17 is positioned above the target substrate 9. At this time, the tip of the application needle 170 is immersed in the ink in the ink tank 172.

Next, as shown in FIG. 11( b ), the application needle 170 is lowered, and the tip of the application needle 170 protrudes from the hole at the bottom of the ink tank 172. At this time, ink adheres to the tip of the application needle 170. Then, as shown in FIG. 11( c ), the application needle 170 and the ink tank 172 are lowered, the tip of the application needle 170 is brought into contact with the substrate 9, and ink is applied to the substrate 9. Then, return to the state of Fig. 11 (a).

The ink coating mechanism using a plurality of coating needles is also known for various techniques, so detailed description is omitted. It is disclosed in Patent Document 1, for example. The coating apparatus 100 can use the mechanism shown in, for example, FIG. 10 as the ink coating mechanism 50 to coat the desired ink among the plurality of types of ink, and can also use the coating required among the plurality of coating needles Diameter of the coating needle to apply ink.

The head 10 (FIG. 1) of the shape measuring device according to the present invention is provided in, for example, the observation optical system 2 of the coating device 100. The control computer 70 controls the ink application mechanism 50, and after performing the ink application operation, moves the Z table 40, thereby positioning the head 10 above the surface of the ink application portion Established location. The control computer 70 further moves the Z table 40 relative to the substrate 9 while taking images of interference light by the CCD camera 4. The control computer 70 detects the position of the Z table where the intensity of the interference light peaks for each pixel, and then uses the detected position of the Z table to calculate the film thickness of the ink application portion or the height of the uneven portion.

[Explanation of ink application operation]

Next, the details of the ink application operation performed by the coating device 100 will be described using FIGS. 12 to 16.

The coating apparatus 100 uses the Z table 40 to relatively move the Milau interferometer 3 to the object, and then automatically detects the focus according to the method shown in the first embodiment, and uses the detected focus position as a reference To perform ink application.

The interference fringes generated by the Milau interferometer 3 appear when the focus is on the surface to be detected. Therefore, as the reference plane in the height direction of the coating operation, for example, when a smooth surface without unevenness such as a surface of glass, a metal thin film, or a chromium film is used, it is effective when focusing. When the coating device 100 is used in the assembly process of an electronic component, etc., as a reference surface in the height direction of the coating operation, a smooth surface such as a metal thin film is selected.

Moreover, as shown in FIG. 5, since the width of the foothills of the mountain-shaped waveform of the separation degree is as small as a few μm and sharp peaks clearly appear, the focus position can be detected with high accuracy.

Here, as shown in FIG. 12, an example of the operation in the case where the ink is applied to the application section 92 will be described using the area AR on the surface of the metal thin film 91 on the substrate 9 as the reference plane in the height direction. In addition, the metal film 91 is coated with The part 92 is regarded as the same height.

The offset between the coating portion 92 and the front end of the coating needle 170 is obtained in advance and stored in the control computer 70 of the coating device 100. The offset amount is obtained as shown below.

As shown in FIG. 13, the computer 70 for control uses the method shown in the first embodiment to focus on the area AR set on the surface of the metal thin film 91 which is the reference plane. Specifically, a brightness distribution map is obtained for the pixels in the area AR, and then the degree of separation R is calculated based on the brightness distribution map, and the autofocus operation is performed.

Next, the control computer 70 moves the movable plate 15 of the ink application mechanism 50 of the application device 100 in the X-axis direction or the Y-axis direction in FIG. 10, and moves the application needle 170 above the application portion 92 . Then, as shown in FIG. 14, the control computer 70 controls the ink application mechanism 50 after lowering the Z table 40 by only Δz, and after the application operation described in FIG. 11 is performed, causes the movable plate 15 Go back to the original position.

Confirm that the monitor 74 of the coating apparatus 100 changes Δz when the ink is not applied to the coating section 92, and then execute the above steps. This operation is repeated until the ink is applied to the application section 92, and Δz at the time of the initial application is stored in the control computer 70.

In the actual coating operation, using the method shown in the first embodiment, after focusing on the surface of the metal thin film 91 that is the reference plane, the movable plate 15 of the ink coating mechanism 50 of the coating device 100 is placed on the In the X-axis direction or the Y-axis direction of FIG. 10, the coating needle 170 is moved above the coating portion 92. Then, after lowering the Z stage 40 by only Δz, the ink application mechanism 50 is controlled, After performing the coating operation, the movable plate 15 is returned to the original position.

In the above description, the metal thin film 91 and the coating portion 92 are described as being at the same height. However, as shown in FIG. 15, when the coating portion 92 is higher than the metal thin film 91, the Z table 40 is used. Move only those that subtract △d from △z (△z-△d). In addition, as shown in FIG. 16, when the coating portion 92 is lower than the metal thin film 91, the Z table 40 is moved only by (Δz+Δd) added to the Δz by the step difference Δd. In addition, here, the descending direction of the Z table 40 is regarded as positive.

[Explanation of film thickness inspection method]

In the above method, after the ink is applied to the application section 92, the film thickness of the applied ink is checked. As a method of measuring the film thickness, for example, the method described in Japanese Patent Laid-Open No. 2015-007564 can be used to measure the surface shape. As shown in FIG. 17, the step Δt between the apex portion of the metal thin film 91 and the applied ink 94 is obtained.

When the obtained step difference Δt is smaller than the lower limit value TL stored in the control computer 70 of the coating device 100 in advance, the ink is applied again. At this time, if the film thickness of the applied ink is Δt, the offset amount of the Z table 40 is set to (Δz-Δt), and the ink is applied. This action is repeatedly performed until the ink film thickness Δt exceeds the lower limit value TL. However, the number of coating times i is counted, and the coating operation is interrupted when i exceeds the predetermined maximum number of times N.

When the coating operation is interrupted, the operator confirms the state of the coating unit 92 on the monitor 74, and determines whether or not the coating is correctly performed.

Fig. 18 is a flowchart for explaining the film thickness inspection process executed by the control computer 70.

Referring to FIG. 18, when starting to perform the coating operation, the control computer 70 is in step (hereinafter abbreviated as S) S100, focusing on the predetermined reference surface of the metal thin film 91 as shown in FIG. 12 (No. 13) Figure), based on the focal distance to the reference surface at this time, and the preset offset of the height direction of the objective lens 19 and the coating needle 170, the control computer 70 calculates the height △ from the reference surface to the front end of the coating needle 170 z.

Then, the computer 70 for control moves the X stage 42 and the Y stage 44 and the application needle 170 moves above the application unit 92.

Next, the control computer 70 initializes the count value i indicating the number of coatings to i=1 at S110, and moves the process to S120. In S120, the control computer 70 determines whether the count value i is equal to or less than a predetermined maximum number of times N.

When the count value i is equal to or less than the predetermined maximum number of times N (i≦N) (Yes at S120), the process is moved to S130, and the control computer 70 causes the Z table 40 to be lowered by only △z, and the coating is applied. The portion 92 is coated with ink (Figure 14).

Then, the computer 70 for control raises the Z table 40 by Δz only, returns to the initial position, and then positions the objective lens 19 above the coating section 92. Next, the control computer 70 is at S140, and while moving the Z stage 40 relative to the substrate 9 in the height direction, the CCD camera 4 is used to capture the image of the interference light, and the intensity of the interference light becomes the peak Z stage 40 Measure the height Δt from the reference surface of the vertex of the applied ink (Figure 17).

The control computer 70 determines whether the measured film thickness Δt of the ink portion is equal to or greater than the predetermined lower limit TL (Δt≧TL) at S150.

In the case where the film thickness Δt is less than the lower limit value TL (NO in S150), since the coating amount is insufficient, the computer 70 for control increases the count value i in S160 Add and return the process to S120, and then perform the coating operation, at this time, the amount of descent of the coating needle 170 is corrected to (Δz-Δt).

In addition, in the process of repeatedly performing the above coating operation, when the count value i exceeds the predetermined maximum number N (i>N) (NO at S120), the control computer 70 interrupts the coating operation.

In addition, when the film thickness Δt is equal to or higher than the lower limit value TL (YES in S150), the coating computer 70 ends the coating operation as if the coating is completed.

As described above, using the shape measuring device according to the present embodiment, the coating device 100 is controlled according to the above-described processing, whereby the height of the applied ink can be measured with high accuracy and high efficiency, so the work efficiency can be improved . In addition, by first performing the coating operation after focusing on the reference plane, since the positional relationship between the coating needle and the coating portion is stable, the amount of ink adhering to the coating portion can be stabilized.

Furthermore, the film thickness after coating is measured, and the coating operation is repeatedly performed until the film thickness exceeds a predetermined amount, thereby reducing the defect of the product caused by the insufficient coating amount. In addition, the manpower and time for correcting defective products can be omitted, so the manufacturing cycle can be improved.

It should be considered that the embodiment disclosed this time is an example on all matters, not a limitation. The scope of the present invention is not the above description, but is expressed by the scope of patent application, and the plot includes the same meaning as the scope of patent application and all changes within the scope.

1‧‧‧Lighting

2‧‧‧Observation optical system

3‧‧‧Mirau interferometer

4‧‧‧Camera device

5‧‧‧ Piezo worktable

6‧‧‧Control device

7‧‧‧Object

10‧‧‧Head

Claims (11)

A shape measuring device for measuring the surface shape of an object, including an interferometer, which separates the white light emitted from the lighting device into first and second light beams, and irradiates the first light beam on the surface of the object And irradiate the second light beam to the reference surface, and then combine the reflected light from the surface of the object with the reflected light from the reference surface to produce interference fringes corresponding to the surface shape of the object; the observation optical system is used To observe the interference fringes; an imaging device to capture the image of the interference fringes via the observation optical system; a first positioning device to relatively move the object and the interferometer in the optical axis direction; and a control device to control The imaging device and the first positioning device perform a first auto-focusing operation that focuses the interferometer on the surface of the object; the control device causes the object and the first auto-focusing operation during the first auto-focusing operation The interferometer moves relatively in the direction of the optical axis, while shooting each image at a plurality of relative positions, the brightness distribution map of the plurality of pixels included in the image in each image, the resolution is obtained according to the discriminant analysis method, and then The object and the interferometer are arranged at relative positions corresponding to the image having the largest degree of separation among the plurality of images. A shape measuring device as claimed in item 1 of the patent application, wherein in the discriminant analysis method, the brightness distribution map of the plurality of pixels is divided into two levels according to the brightness threshold, and the brightness threshold is set within the level The dispersion becomes the smallest, and the dispersion between the levels becomes the largest, and the dispersion between the levels is within the level The ratio of dispersion is used as the degree of separation. The shape measuring device according to item 1 or 2 of the patent application scope, wherein the interferometer is a Milau interferometer, and the milau interferometer includes: an objective lens, which is arranged to face the surface of the object; a semi-transmissive mirror , Which is arranged between the objective lens and the surface of the object; and the mirror, which is opposite to the semi-transmissive mirror, and has the reference plane arranged at the central part of the objective lens; emitted from the illumination device The white light is refracted by the objective lens, enters the semi-transmissive mirror, and is separated into the first light beam passing through the semi-transmissive mirror and the second light beam reflected by the semi-transmissive mirror; the first light beam is irradiated on The surface of the object and the second light beam irradiates the reference surface, the reflected light from the surface of the object and the reflected light from the reference surface are synthesized at the semi-transmissive mirror to become interference light, and then the interference light The interference fringes are generated; the optical axis and focal point of the Milau interferometer are the optical axis and focal point of the objective lens, respectively. For example, the shape measuring device according to item 3 of the patent application scope includes a second positioning device that moves the interferometer relative to the object in the optical axis direction; the stroke of the second positioning device is higher than that of the first positioning device The stroke is longer; the control device controls the imaging device and the second positioning device before performing the first autofocusing action, and performs the second autofocusing action for coarsely adjusting the position of the focus of the interferometer; In the second autofocus operation, while moving the object and the interferometer relative to each other in the optical axis direction, each image is captured at a plurality of relative positions, and the plurality of pixels included in the image in each image is obtained The differential value of the brightness, and then the object and the interferometer are arranged at a relative position corresponding to the image having the largest differential value among the plurality of images. A shape measuring device as claimed in item 4 of the patent application, wherein the first positioning device is fixed to the observation optical system and moves the interferometer; at least the first positioning device, the observation optical system and the interferometer system An optical unit is formed; the second positioning device moves the optical unit. For example, the shape measuring device according to item 1 or 2 of the patent application includes a second positioning device that moves the interferometer relative to the object in the optical axis direction; the stroke of the second positioning device is greater than that of the first The stroke of the positioning device is longer; the control device controls the imaging device and the second positioning device before performing the first auto-focusing operation, and performs the second auto-focusing operation for coarsely adjusting the position of the focus of the interferometer ; In the second autofocus operation, while moving the object and the interferometer relative to each other in the optical axis direction, while shooting each image at a plurality of relative positions, the plurality of images contained in each image is obtained The differential value of the brightness of the pixel, and then the object and the interferometer are arranged at a relative position corresponding to the image having the largest differential value among the plurality of images. For example, the shape measuring device according to item 6 of the patent application, in which the first positioning The device is fixed to the observation optical system and moves the interferometer; at least the first positioning device, the observation optical system, and the interferometer constitute an optical unit; and the second positioning device moves the optical unit. A coating device for coating a liquid material on a surface of an object, including: a coating unit having an application needle and applying the liquid material attached to the front end of the application needle to the object The surface of the object; the head consists of the following components. The interferometer separates the white light emitted from the lighting device into the first and second light beams, and irradiates the first light beam on the surface of the object And irradiate the second light beam to the reference surface, and then combine the reflected light from the surface of the object with the reflected light from the reference surface to produce interference fringes corresponding to the surface shape of the object; the observation optical system is used To observe the interference fringes; an imaging device to capture an image of the interference fringes via the observation optical system; and a first positioning device to relatively move the object and the interferometer in the optical axis direction; a second positioning device, The head and the object are relatively moved in a direction orthogonal to the optical axis direction, and the head is positioned at a desired position above the surface of the object; and the control device is located at the first Autofocus action, while moving the object and the interferometer relatively in the direction of the optical axis, while shooting each image at a plurality of relative positions, the brightness distribution map of the plurality of pixels included in the image in each image, according to The discriminant analysis method is used to obtain the degree of separation, and then the object and the interferometer are arranged at a relative position corresponding to the image having the largest degree of separation among the plurality of images. For example, the coating device according to item 8 of the patent application, in which the control device is in the first autofocus operation, after focusing on the reference plane set on the object, the coating needle The liquid material is applied to the surface of the object. For example, the coating device according to item 9 of the patent application, in which the control device determines the step difference between the reference plane and the vertex of the applied liquid material after applying the liquid material, and overlaps the application Operate until the calculated difference exceeds the preset lower limit. For example, the coating device according to any one of claims 8 to 10, wherein the stroke of the second positioning device is longer than the stroke of the first positioning device; the control device is performing the first autofocusing action Previously, the imaging device and the second positioning device were controlled to perform a second autofocus operation that coarsely adjusts the position of the focus of the interferometer; in the second autofocus operation, the object and the interferometer are The direction of the optical axis is relatively moved, while each image is taken at a plurality of relative positions, the differential value of the brightness of the plurality of pixels included in the image in each image is obtained, and then the object and the interferometer are arranged in the The differential value in the plurality of images becomes the relative position corresponding to the image with the largest value.

Images