JP6415948B2 - Shape measuring device - Google Patents

Description

  The present invention relates to a shape and the like measuring device, and relates to a technique for measuring the surface of a metal or resin and the surface of a processed product thereof, the surface of a substrate such as a semiconductor, an electronic circuit, or a flat display, and inspecting these surfaces.

  Pattern processing technology using an application needle with a tip diameter of several tens of μm and laser light with a spot diameter of several μm to 10 μm can be used in combination with precision positioning technology on the order of micrometers, so that a predetermined position can be obtained even in a fine pattern. It can be processed accurately. For this reason, the said pattern processing technique has conventionally been utilized for the correction | amendment operation | work of a flat panel display, the scribe operation | work of a solar cell, etc. (for example, refer patent documents 1-3).

  In particular, the processing technique using an application needle can also apply a paste having a high viscosity, which is not good for a dispenser, and has recently been used to form a film having a thickness of 10 μm or more as compared with a flat panel display. For example, it is used for forming electronic circuit patterns and printed circuit board wiring of semiconductor devices such as MEMS and sensors. Patterns produced by printed electronics technology, which is a promising manufacturing technology in the future, are also classified as thick films, and are expected to be used in the future.

  In the fine processing as described above, it is important to determine whether or not the processing is normally performed after the processing. For example, in the correction of the color filter substrate constituting the liquid crystal panel, the quality of the processed portion is inspected after the correction. A technique is proposed in Patent Document 2.

JP 2009-122259 A JP 2009-237086 A JP 2012-6077 A

In Patent Document 2, images of regions including defects before and after the correction process are captured, the brightness of the images before and after the correction process are compared, and abnormality in the correction process is detected based on the comparison result.
However, for example, in the case of a color filter substrate, if ink is excessively applied to the correction portion, a protrusion defect is formed, and bonding to the TFT substrate is impossible. In addition, in the printed circuit board wiring, when the ink is applied to the defective portion of the wiring pattern to correct it, if the coating amount is insufficient, the resistance value increases and the board may not operate normally.

  As for shape measurement, there is a method using a white interferometer having a relatively simple configuration that can perform non-contact measurement. The white interferometer can use a microscope tube of an inspection apparatus and can be easily added to the apparatus. In addition, it is not necessary to use a special illumination device such as a laser, a white light source generally used in a microscope can be used, and an inexpensive shape measurement function can be provided.

  However, when focusing on an object, interference fringes become an obstacle, and appearance inspection using a photographed image is difficult. Moreover, if a microscope tube for visual inspection is added, the price of the apparatus increases.

  An object of the present invention is to provide a measuring apparatus for shape and the like that can measure or inspect the shape and surface of an object while reducing the cost of the apparatus as compared with the prior art.

The shape measuring device of the present invention is a shape measuring device for measuring or inspecting the shape and surface of an object,
A lighting device that outputs broadband light;
An optical system that irradiates the surface of the object with the broadband light output from the illuminating device, branches the reflected light from the surface of the object, and guides it to two optical paths;
Two imaging devices for imaging the reflected light branched by the optical system,
With
The optical system includes an imaging lens that forms an image of reflected light on each imaging surface of the two imaging devices,
The imaging surface of one imaging device in the two imaging devices is arranged at the focal position of the imaging lens corresponding to the one imaging device, and the imaging surface of the other imaging device corresponds to the other imaging device. It is characterized by being shifted in the optical axis direction with respect to the focal position of the imaging lens.

  The optical system has an interference objective lens interposed in the middle of the optical path between the illumination device and the object, and the interference objective lens separates the broadband light emitted from the illumination device into two light beams. A lens that irradiates the surface of the object with one light beam and irradiates the other light beam onto a predetermined reference surface to interfere with reflected light from the surface of the object and the reference surface, The interference light from the interference objective lens may be imaged on the imaging surface of the one imaging device, and the reflected light may be imaged on the imaging surface of the other imaging device.

  In this case, the interference light can be observed when the interference objective lens is focused on the surface of the object. Therefore, on the imaging surface of one imaging device arranged at the focal position of the imaging lens, the interference light can be observed when the distance between the interference objective lens and the object is equal to the working distance of the interference objective lens. On the imaging surface of the other imaging device, the working distance of the interference objective lens is shortened because it is displaced in the optical axis direction from the focal position of the imaging lens, and the interference light is observed at the position where the focused image is captured. Never do. From the above, it is possible to measure the shape of an object using interference light and perform surface inspection of the object using reflected light with only one optical system without using a plurality of optical systems.

  Therefore, when measuring or inspecting the shape and surface of the object, for example, the cost can be reduced as compared with the prior art in which a microscope tube for appearance inspection needs to be added.

You may provide the position adjustment means which shifts the imaging lens corresponding to the said other imaging device relatively to an optical axis direction with respect to the imaging surface of said other imaging device.
The position adjusting means may be a spacer disposed between the other imaging device and the optical system. For example, when the other imaging device is attached to the optical system, the position can be easily adjusted by providing a spacer such as a close-up ring on the mounting portion of the imaging device in the optical system.

  The position adjusting unit may be a stage capable of adjusting the position of the imaging lens relative to the imaging surface in the optical axis direction. In this case, the imaging lens can be arranged close to the imaging surface as well as relatively far away.

  The shape and the like measuring device of the present invention is a shape and the like measuring device for measuring or inspecting the shape and surface of an object, the lighting device outputting broadband light, and the broadband light output from the lighting device as the target An optical system that irradiates the surface of the object, divides the reflected light from the surface of the object and guides it to the two optical paths, and two imaging devices that respectively image the reflected light branched by the optical system, The optical system includes an imaging lens that forms an image of reflected light on each imaging surface of the two imaging devices, and the imaging surface of one imaging device in the two imaging devices is connected to the one imaging device. The imaging lens of the other imaging device is arranged at the focal position of the corresponding imaging lens, and the imaging surface of the other imaging device is arranged shifted in the optical axis direction with respect to the focal position of the imaging lens corresponding to the other imaging device. For this reason, it is possible to measure the shape and the surface of the object while reducing the cost of the apparatus as compared with the prior art.

It is a figure which shows roughly the structure of the shape etc. measuring apparatus which concerns on embodiment of this invention. It is a figure which shows the example which changed the working distance of a target object and an optical system with the same shape etc. measuring apparatus. It is a figure which shows schematically the structure of the shape etc. measuring apparatus which concerns on other embodiment of this invention. It is a figure which shows schematically the structure of the shape etc. measuring apparatus which concerns on other embodiment of this invention. It is a figure which shows schematically the structure of the shape etc. measuring apparatus which concerns on other embodiment of this invention. It is a figure which shows schematically the structure of the shape etc. measuring apparatus which concerns on other embodiment of this invention.

A shape measuring apparatus according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, this shape measuring device is a device that measures the shape and surface of an object and inspects the surface of the object. Examples of the object include substrates such as metals and resins and processed products thereof, semiconductors and electronic circuits, substrates serving as materials for solar cells, and flat displays. However, it is not limited to these objects.

  This measuring apparatus for shape and the like includes an illumination device 1, an optical system 15, two imaging devices 10 and 11, and a position adjusting unit 16. The lighting device 1 includes a white light source. This white light source outputs broadband light that uniformly includes frequency components in the visible light range.

<The optical system 15 is demonstrated. >
The optical system 15 irradiates the surface of the object 14 with the broadband light output from the illumination device 1, branches the reflected light from the surface of the object 14, and guides it to two optical paths. This optical system 15 is an optical system for infinity correction configured such that the reflected light of the object 14 that has passed through the objective lens 5 described later enters the imaging lenses 8 and 9 described later as a parallel light flux. The optical system 15 includes a condenser lens 2, a reflecting mirror 3, a half mirror 4, an objective lens 5, a half mirror 6, an imaging lens 8, a reflecting mirror 7, and an imaging lens 9. The condenser lens 2 is provided in the middle of the optical path between the illuminating device 1 and the reflecting mirror 3, and condenses the broadband light output from the illuminating device 1.

  The reflection mirror 3 reflects the light that has passed through the condenser lens 2 toward the half mirror 4. The half mirror 4 reflects the light from the reflection mirror 3 in the direction of the objective lens 5, transmits the reflected light of the object 14 that has passed through the objective lens 5, and guides it to the half mirror 6. The objective lens 5 irradiates the object 14 with the reflected light of the half mirror 4 and guides the reflected light of the object 14 to the half mirror 4.

  The half mirror 6 branches a part of the reflected light of the object 14 transmitted through the half mirror 4 to the imaging lens 8 and the rest to the reflecting mirror 7. The imaging lens 8 forms an image of the reflected light of the object 14 on the imaging surface 12 of one imaging device 10. The reflection mirror 7 reflects the reflected light of the object 14 branched from the half mirror 6 in the direction of the imaging lens 9. The imaging lens 9 images the reflected light of the object 14 on the imaging surface 13 of the other imaging device 11. The same lens is applied as the imaging lenses 8 and 9.

<The imaging devices 10 and 11 will be described. >
The two imaging devices 10 and 11 respectively capture the reflected light branched by the optical system 15 described above. These imaging devices 10 and 11 are attached to the optical system 15 in this example. The imaging surface 12 of one of the imaging devices 10 and 11 is arranged at the focal position of the imaging lens 8 corresponding to the imaging device 10. Furthermore, the imaging surface 13 of the other imaging device 11 is disposed away from the focal position of the imaging lens 9 corresponding to the imaging device 11 by a distance “D” in the optical axis direction. As a result, the imaging surface 13 of the other imaging device 11 can capture a short distance in which the working distance between the object 14 and the objective lens 5 is shorter than the imaging surface 12 of the one imaging device 10.

<The position adjustment means 16 etc. are demonstrated. >
As shown in FIGS. 1 and 2, the position adjusting unit 16 is a unit that shifts the imaging lens 9 relative to the imaging surface 12 of the imaging device 11 in the optical axis direction. In this example, a spacer such as a close-up ring is applied as the position adjusting means 16. Specifically, when the imaging device 11 is attached to the optical system 15, a spacer such as the close-up ring is inserted into a mounting portion of the imaging device 11 in the optical system 15. Thereby, the imaging surface 13 of the imaging device 11 can be disposed away from the focal position of the imaging lens 9 in the optical axis direction.

  FIG. 1 shows the positional relationship between the object 14 and the shape measuring device when a focused image is being picked up on the imaging surface 12 of the imaging device 10 on the left side of the figure, and the imaging device 11 on the right side of the figure. The imaging surface 13 is not in focus.

On the other hand, FIG. 2 shows the positional relationship between the object 14 and the shape measuring device when a focused image is captured on the imaging surface 13 of the imaging device 11 on the right side of the figure, and the imaging on the left side of the figure. The imaging surface 12 of the device 10 is not in focus. Further, the working distance between the object 14 and the objective lens 5 is shorter in the case of FIG. 2 than in the case of FIG. The working distance is a distance in the optical axis direction from the front surface (the lower surface in this example) of the objective lens 5 to the in-focus position.
Although the distance between the imaging surface 13 and the imaging lens 9 has been changed so far, the distance between the imaging surface 12 and the imaging lens 8 may be changed.

  According to the shape measuring apparatus described above, for example, when the surface property of the object 14 is inspected after the surface of the object 14 is corrected, the other imaging device is used for a portion where the working distance between the object 14 and the objective lens 5 becomes long. Inspection can be performed using one imaging device 10 that can ensure a working distance longer than 11. Conversely, a portion where the working distance is shortened can be inspected using the other imaging device 11. As described above, the surface property can be inspected with high accuracy and at low cost by selectively using one or the other imaging device 10 or 11 according to the difference in working distance.

Another embodiment will be described.
In the following description, the same reference numerals are given to the portions corresponding to the matters described in the preceding forms in each embodiment, and the overlapping description is omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in advance unless otherwise specified. The same effect is obtained from the same configuration. Not only the combination of the parts specifically described in each embodiment, but also the embodiments can be partially combined as long as the combination does not hinder.

  As shown in FIG. 3, instead of the position adjusting means 16 such as the spacer of FIG. 1, a stage capable of adjusting the position of the imaging lens 9 relative to the imaging surface 13 in the optical axis direction is used as the position adjusting means 16A. It may be provided. In this case, the imaging lens 9 can be arranged close to the imaging surface 13 as well as relatively far away.

  FIG. 4 is a diagram schematically illustrating the configuration of a shape measuring apparatus according to another embodiment. In this shape measuring apparatus, the objective lens 5 in FIG. 1 is changed to a Mirau-type interference objective lens 22. The interference objective lens 22 includes an objective lens 17, a reference mirror 18, and a beam splitter 19. The light incident on the objective lens 17 is divided by the beam splitter 19 into light that passes in the direction of the object 14 and light that reflects in the direction of the reference mirror 18, that is, two lights.

  The lights reflected from the surfaces of the object 14 and the reference mirror 18 are merged again by the beam splitter 19 and collected by the objective lens 17. Thereafter, the light emitted from the objective lens 17 passes through the half mirror 4 and is then guided to the imaging lens 8 and the imaging lens 9 in the same manner as in the above-described embodiment, and the imaging surfaces of the imaging devices 10 and 11 are detected. 12 and 13 respectively.

  FIG. 4 shows the positional relationship between the object 14 and the shape measuring device when a focused image is captured on the imaging surface 12 of the imaging device 10 on the left side of the figure, and the imaging device on the right side of the figure. 11 is not in focus. The interference light is designed to be observed when the interference objective lens 22 is focused on the surface of the object 14.

Therefore, the interference light can be observed on the imaging surface 12 when the distance between the objective lens 17 and the object 14 is equal to the working distance of the objective lens 17. Since the imaging surface 13 is arranged away from the focal position of the imaging lens 9 corresponding to the imaging device 11 by a distance “D” in the optical axis direction, the working distance of the objective lens 17 is short. The interference light is not observed at the position where the focused image is captured.
From the above, the height measurement of the object 14 using the interference light of the imaging surface 12 and the appearance inspection using the image of the imaging surface 13 are performed with only one optical system without using a plurality of optical systems. It can be carried out.

  As shown in FIG. 5, a stage 20 that relatively moves the interference objective lens 22 and the object 14 in the optical axis direction may be provided. The stage 20 is configured so that the entire optical system 15 can be moved relative to the object 14.

  As shown in FIG. 6, a stage 21 that relatively moves the interference objective lens 22 and the object 14 in the optical axis direction may be arranged in a portion where the interference objective lens 22 is attached in the optical system 15. In this case, it is possible to reduce the cost by reducing the size of the stage as compared with the configuration of FIG. Note that it is desirable that the stage 20 in FIG. 5 and the stage 21 in FIG. 6 use piezo stages capable of obtaining sufficient positioning resolution.

  As mentioned above, although the form for implementing this invention based on embodiment was demonstrated, embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 ... Illuminating device 8, 9 ... Imaging lens 10, 11 ... Imaging device 12, 13 ... Imaging surface 14 ... Object 15 ... Optical system 16, 16A ... Position adjustment means 22 ... Interference objective lens

Claims (5)

A shape measuring device for measuring or inspecting the shape and surface of an object,
A lighting device that outputs broadband light;
An optical system that irradiates the surface of the object with the broadband light output from the illuminating device, branches the reflected light from the surface of the object, and guides it to two optical paths;
Two imaging devices for imaging the reflected light branched by the optical system,
With
The optical system includes an imaging lens that forms an image of reflected light on each imaging surface of the two imaging devices,
The imaging surface of one imaging device in the two imaging devices is arranged at the focal position of the imaging lens corresponding to the one imaging device, and the imaging surface of the other imaging device corresponds to the other imaging device. An apparatus for measuring a shape or the like, wherein the measuring device is arranged so as to be shifted in an optical axis direction with respect to a focal position of an imaging lens.   The shape measurement apparatus according to claim 1, wherein the optical system includes an interference objective lens interposed in the optical path between the illumination device and the object, and the interference objective lens is emitted from the illumination device. The broadband light is separated into two light beams and one light beam is irradiated onto the surface of the object, and the other light beam is irradiated onto a predetermined reference surface and reflected from the surface of the object and the reference surface. An interference light that interferes with light, and forms an image of the interference light from the interference objective lens on the imaging surface of the one imaging device and an image of the reflected light on the imaging surface of the other imaging device Shape measuring device.   3. The shape adjusting device according to claim 1 or 2, wherein a position adjusting unit that shifts an imaging lens corresponding to the other imaging device relative to the imaging surface of the other imaging device in the optical axis direction. Measuring device for shape etc.   4. The shape or the like measuring apparatus according to claim 3, wherein the position adjusting means is a spacer disposed between the other imaging device and the optical system. 4. The shape etc. measuring apparatus according to claim 3, wherein the position adjusting means is a stage capable of adjusting the position of the imaging lens relative to the imaging surface in the optical axis direction.

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