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WO2006087213A2 - Procede et dispositif pour detecter et/ou classifier des endroits defectueux - Google Patents

Procede et dispositif pour detecter et/ou classifier des endroits defectueux Download PDF

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Publication number
WO2006087213A2
WO2006087213A2 PCT/EP2006/001465 EP2006001465W WO2006087213A2 WO 2006087213 A2 WO2006087213 A2 WO 2006087213A2 EP 2006001465 W EP2006001465 W EP 2006001465W WO 2006087213 A2 WO2006087213 A2 WO 2006087213A2
Authority
WO
WIPO (PCT)
Prior art keywords
light
vorrichtung
vorrichtung according
substrate
workpiece
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/EP2006/001465
Other languages
German (de)
English (en)
Other versions
WO2006087213A3 (fr
Inventor
Klaus Gerstner
Clemens Ottermann
Bernhard Hunzinger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Schott AG
Original Assignee
Schott AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE200510007715 external-priority patent/DE102005007715B4/de
Application filed by Schott AG filed Critical Schott AG
Priority to KR1020077021449A priority Critical patent/KR101332786B1/ko
Publication of WO2006087213A2 publication Critical patent/WO2006087213A2/fr
Publication of WO2006087213A3 publication Critical patent/WO2006087213A3/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/89—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/89—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles
    • G01N21/892—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles characterised by the flaw, defect or object feature examined
    • G01N21/896—Optical defects in or on transparent materials, e.g. distortion, surface flaws in conveyed flat sheet or rod
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/89—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles
    • G01N21/8901—Optical details; Scanning details
    • G01N21/8903—Optical details; Scanning details using a multiple detector array
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y20/00—Nanooptics, e.g. quantum optics or photonic crystals
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/94—Investigating contamination, e.g. dust

Definitions

  • the invention generally relates to the quality control in the production and / or processing of workpieces, in particular the optical detection and / or
  • the invention is therefore based on the object to be able to provide an optical error detection and classification of errors of substrates, which even at high speed error detection meets the highest quality assurance requirements.
  • the invention provides an apparatus and a method for detecting defects, in particular on surfaces of workpieces, preferably plate-shaped workpieces, such as glass plates, in which radiation is directed to a workpiece and is at least partially influenced by the workpiece, preferably by the defect.
  • it is provided to detect at least part of the radiation influenced by the defect from an optical detector.
  • According to one embodiment of the invention is also an apparatus and a method for detecting and / or classification of defects, especially on surfaces of workpieces, in which radiation at least one light source is directed to a workpiece and is at least partially influenced by the workpiece, preferably by the defect , in which a first and a second optical signal is generated and from these signals a distinction of the defect is possible.
  • the invention provides a device for detecting and / or classifying defects, in particular on surfaces of workpieces, wherein radiation of at least one light source is directed to a workpiece and is at least partially influenced by the workpiece, preferably by the defect, in which a first and a second optical signal is generated and from these signals a distinction of the defect is possible.
  • the subsequent processing can be influenced very positively.
  • a substrate may be supplied for further purification, for example.
  • a ' storage of the ' location of one or more detected particles and / or detected scratches in a subsequent data processing system can be carried out, which controls the further processing operations.
  • particles with diameters in a range of one-half to five micrometers are still reliably detectable and distinguishable from scratches and bubbles in the glass.
  • These particles can be both externally introduced solids and remaining residues of a previous cleaning process, such as detergent residues or very fine droplets on the glass surface.
  • the illumination comprises a bright field and a dark field illumination arrangement.
  • the or the optical detectors are arranged so that they detect at least areas of the dark field.
  • one or more lasers are suitable.
  • the light source may comprise a scanning system for scanning the workpiece, in particular in conjunction with a line scan camera or another detector with parallel detection of multiple surface areas or with the scanning system synchronized optical detection.
  • the optical detector preferably comprises a plurality of light-detecting pixels, each. detect light originating from different substrate areas in order to be able to examine large surface areas simultaneously with high accuracy. Different areas of the substrate do not necessarily mean disjoint areas here, but rather the areas may partially overlap, for example. Furthermore, a lighting device is provided which has a plurality of light source points, which are arranged so that falls on each of the substrate regions light from at least two different directions of incidence. This is advantageous for being able to detect elongated structures, such as scratches, since the light scattering on such structures is generally strongly dependent on the angle between scratch and incident light. In this way it is also possible to reliably detect any scratches along the surface and only slight scratches.
  • the directions of incidence include an angle of at least 45 °, preferably of at least 90 °, particularly preferably of at least 120 °.
  • An angle between two directions of incidence of at least 120 ° is particularly favorable when the light from more than two directions on the respective surface area, so for example from at least three directions on the surface falls.
  • a light source does not necessarily have to be a separate light source. Rather, the light of one or more light sources can be divided in a suitable manner.
  • the optical detector comprises a line camera, with which along the surface elongated regions of the substrate to be tested are verifiable in parallel.
  • the optical detector comprises an imaging camera, with which the substrate along the surface sections, or even can be detected at once.
  • the optical detector can be particularly advantageously preceded by a 4f arrangement. It has surprisingly been found that such an arrangement is able to emphasize light scattering effects on defects of the substrate particularly. This is especially the case when the 4F Anor.dnung is arranged such that it performs a filtering of structure sizes, which does not correspond to the structure size of the defects to be detected. Likewise, with the same advantages, alternatively or additionally, the illumination device can be followed by a 4F arrangement.
  • the lighting comprises a
  • the or the optical detectors are arranged so that they detect at least areas of the dark field.
  • a dark field arrangement is just by the elimination of the direct light signal for detecting particularly small errors, so suitable for the highest requirements. According to yet another embodiment of the invention is the
  • the dark field illumination arrangement confocal to the optical axis of the optical detector arranged in reflection to turn off remaining background signal.
  • the dark field illumination arrangement can be arranged confocal to the optical axis of the optical detector in transmission.
  • the illumination may further include a phase contrast illumination arrangement. Even with such an arrangement, the smallest deviations in surface or volume structure can be detected with high contrast.
  • the illumination can be made according to the invention both in transmission, as well as in reflection, as well as in combination of transmission and reflection.
  • the illumination is made with obliquely incident light. It becomes oblique incidentally in the sense of the invention as incident obliquely to the illuminated surface of the substrate understood.
  • the obliquely incident light may advantageously comprise a narrow light beam which illuminates only one of the two main surfaces of a substrate to be tested in the field of view of the camera.
  • the light is focused and irradiated at an oblique incidence on the substrate, wherein the optical axis of the
  • Detector is arranged at an angle ⁇ to the light beam, for which applies:
  • the focus is understood to be the area of smallest expansion perpendicular to the direction of light propagation, at which the intensity of the boundary has dropped to 1 / e relative to the maximum intensity.
  • the focus is particularly preferably within the substrate. In this way, a dark field view is made possible, in which the illuminated by light beam surfaces are adjacent to each other so that they do not overlap from the perspective of the detector. At the same time, the focusing achieves a high light intensity at the substrate surfaces.
  • the distance between the areas illuminated on the surfaces in projection onto the viewing direction of the optical detector is preferably in the range from 100 ⁇ m to 500 ⁇ m.
  • the detector can in particular also be directed perpendicular to the substrate surface.
  • the angle ⁇ then corresponds to the light incidence angle.
  • the detector is further arranged on the light exit side of the substrate and views the illuminated area at an acute angle to the emergent beam.
  • the angle is preferably more than 5 ° and more preferably less than 50 ° to the light-out direction, more preferably in the range of 10 ° to 35 °. More than 5 ° have proven to be beneficial to direct posts
  • the optical detector may comprise a camera with at least two lines. It is positioned with respect to the light source and the substrate so that one of the lines detects the surface area illuminated by the light striking the substrate and the other line detects the surface area illuminated by the light exiting the substrate.
  • a further general improvement of the invention for detecting extremely weak scatterers on the surfaces consists in the use of a signal amplifier for the optical detector, in particular a photomultiplier or a multi-channel plate.
  • the optical detector can then be used in particular in conjunction with a scanning light beam.
  • the light beam can be focused to increase the light intensity and spatial resolution. Particularly suitable is focused laser radiation, which is scanned with a scanning system over the surface of the workpiece.
  • an imaging detector in particular a multi-channel plate can be used, which is the
  • a light source with an irradiance on the substrate of at least 2.5 ⁇ 10 6 watts per square meter and a scattered light detection is used.
  • Such light intensities can be achieved in particular by means of focused light sources.
  • a focused light source having a focus with a minimum extension of at most 200 ⁇ m, preferably at most 150 ⁇ m.
  • the obliquely incident light can also be s-polarized in an advantageous manner.
  • the reflection at defect-free areas of the surface of the substrate to be tested is reduced, so that an improved signal-to-noise ratio of the originating from surface defects scattered light signal is achieved. It is particularly advantageous if the obliquely incident light is irradiated relative to the workpiece under the Brewster angle.
  • the optical detector having a similar effect may comprise a polarizer which polarizes the light substantially perpendicular to the polarization of the light reflected from the workpiece.
  • the term "essentially” means in particular that this applies to the main surface, but not to the defect, for example, In other words, the polarizer is adjusted so that light reflected from defect-free regions of the surface is blocked.
  • the illumination comprises a laterally arranged from the optical detector lighting, which lower or no light components perpendicular to the substrate surface.
  • the illumination means may comprise in vorteilha 'fter further also mirror for beam shaping.
  • the illumination device comprises faceted mirrors for defining a plurality of foci on the workpiece, from which spherical waves emanate. Another way to provide illumination with a variety of individual light sources is.
  • Lighting device with at least one holographic optical element for defining a plurality of foci on the workpiece may comprise a phase hologram, which preferably includes vapor deposition glass.
  • the structures holographically effective structures can be prepared by structured vapor deposition of a vapor-deposited glass.
  • the holographic optical element may be arranged in particular on a refractive element, such that the desired illumination of the substrate can be performed by one or more light sources which irradiate the holographic 'optical element.
  • the holographic optical element is arranged on a reflective element.
  • the light source may advantageously also comprise a holographic optical element and a cylindrical lens in order to achieve the desired angular distribution of the light incident on the workpiece.
  • the one or more light sources used can advantageously also be limited in their bandwidth.
  • the scattering intensity is generally dependent on both the shape and the size of the scattering elements. To be able to detect the smallest possible defects is In this regard, for example, the use of a light source whose spectrum is at wavelengths less than 300 nm, advantageous.
  • the light source can advantageously emit light at a wavelength at which. the workpiece to be tested has only low transmission, in particular a transmission of less than 50%, preferably less than 25%, most preferably less than 15%. In this way, it can also be easily distinguished on detection of a surface defect or a surface contamination on which side of the workpiece the defect found. When using further light sources, in which the workpiece is transparent, it is then also possible to distinguish between surface and volume defects. '
  • one or more lasers are suitable.
  • the light source may comprise a scanning system for scanning the workpiece, in particular in conjunction with a line scan camera or another detector with parallel detection of multiple surface areas or with the scanning system synchronized optical detection.
  • a laser diode array is used, which for example, includes a collimator assembly which generates a single light beam.
  • a light source is advantageous, inter alia, in conjunction with a line scan camera as an optical detector.
  • a laser or laser diode array may further be defined to adapt the longitudinal coherence to a plurality of longitudinal. Emit fads. It is further contemplated that the laser or laser diode array may be short pulsed, or operable to define desired longitudinal coherence characteristics.
  • the laser diode array may comprise at least one FAC and preferably additionally at least one SAC lens which generates at least one focus on the workpiece.
  • the light source may also include a phase framer to define desired transverse coherence. This makes it possible, in particular, to switch off unwanted interference effects that cause false signals.
  • the light source may also comprise a fluorescent or fluorescent tube.
  • a fluorescent or fluorescent tube With such a light source, a plurality of surface areas can be illuminated in particular in an arrangement parallel to the surface of the workpiece so that the respective surface areas are illuminated in each case by light from different directions.
  • a fluorescent tube with several spectral emission bands can also be used.
  • a fluorescent or fluorescent tube is arranged parallel to a line scan camera as part of the optical detector.
  • the workpiece comprises glass, or glass is examined as a workpiece.
  • the invention thin glass can be examined with the invention thin glass.
  • the invention is suitable in this respect for checking the quality of floated thin glass, downdraw thin glass, downdraw fusion thin glass, in particular overfiow downdraw glass.
  • Glass inspection apparatus for a display in particular a TFT display.
  • such glasses are subject to particularly stringent requirements, since even the smallest scratches, which can occur during polishing or during handling in the production process, can adversely affect the coatings applied to the glass.
  • Substrates such as thin glass with a width of more than 1.8 meters and / or a length of more than 2.0 meters according to the invention can be checked so quickly that the production process in the production of TFT displays such substrates is not or only slightly slowed down.
  • Thin glass which has been tested with a device according to the invention and sorted using the test results, has in this way a significantly reduced error concentration or number of errors.
  • concentration itself of scratches having a depth of 3 ' to 30 nanometers should be less than 5, preferably less than 3, more preferably less than 1 per square meter.
  • Fig. 'L in a schematic view a device for detecting flaws on thin glass according to an embodiment of the invention
  • FIG. 2 shows a variant of the device shown in Fig. 1, 3A, 3B parts of developments of devices according to the invention
  • Fig. 4 shows a further embodiment of the invention with
  • Fig. 6 shows an embodiment with straightening
  • Fig. 8 shows a variant of that shown in Fig. 7
  • Fig. 9 shows a development of the invention with a plurality of juxtaposed optical
  • a receptacle with an optical detector such as can be obtained with a device according to Fig. 7 Fig. 10 ⁇ .
  • Fig. 11 is a greatly simplified schematic
  • FIG. 12 is a greatly simplified schematic
  • Fig. 13 shows a preferred embodiment of the device according to the invention.
  • FIG. 1 shows a schematic view of a device for detecting defects on and / or in workpieces 3.
  • the apparatus of this exemplary embodiment designated as a whole by the reference numeral 1
  • thin-glass substrates 3 are checked for the presence of defects.
  • Typical errors can be detected, such as those caused by the manufacturing process, for example with downdraw thin glass, downdraw fusion thin glass, in particular overflow downdraw glass or float glass, as well as due to postprocessing.
  • the device is also surprisingly suitable for rapid testing of very large substrates, such as thin glass with a width of more than 1.8 m. and / or a length of more than 2, 0 m.
  • the device 1 for detecting defects radiation is directed by means of a lighting device 11 on the workpiece and at least partially influenced by the workpiece, in particular by the defect. At least part of the radiation influenced by the defect is then detected by an optical detector 5.
  • the optical detector comprises in particular a line camera 7.
  • a Focusing optics of the line scan camera is designed so that each pixel of the camera 7 detects a different surface area of the thin-glass substrate 3, or from this outgoing light. The totality of the detected surface areas gives an elongated
  • the surface region 20 extends in particular along the entire width of the substrate 3, so that the entire surface 31 or the entire substrate 3 can be detected by a single pass from the substrate at the optical detector 5. For this purpose, both the substrate 3, and the detector can be moved.
  • the illumination device 11 is formed so as to form a plurality of light source spots arranged so that light from at least two different directions of incidence falls on each of the substrate regions which detect the individual pixels of the line scan camera.
  • the light source comprising a fluorescent tube 13.
  • This extends parallel to the line scan camera. And is suitably collimated and focused by means of a cylindrical lens 15, so that substantially only the narrow surface area 20 is illuminated.
  • the illumination is made with obliquely incident light, while the line scan camera looks substantially perpendicular to the surface, so that no directly reflected light can enter the line scan camera 7.
  • the fluorescent tube emits its light isotropically, so that any longitudinal section of the fluorescent tube forms a light source. In this way, light falls from many different directions on each of the detected substrate areas. For example, in the case of the arrangement shown in FIG.
  • an area at the very edge of the substrate 3 is covered by light under all possible directions of incidence, which differ at most by an angle .alpha.
  • the length of the fluorescent tube and its distance to the region 20 can then be chosen so that the different directions of incidence make an angle of at least 45 °, preferably at least 90 °, more preferably even at least 120 °. In this way, scratches that run along any direction of the surface can be reliably detected.
  • FIG. 1 which is arranged laterally from the optical detector, wherein the illumination by the illumination device 11 has lower or, in particular, no light components perpendicular to the substrate surface 31.
  • the fluorescent tube can have multiple spectral emission bands. In this way, for example, in conjunction with appropriate
  • the illumination of this embodiment particularly represents a dark field illumination arrangement.
  • FIG. 2 shows a variant of the device 1 shown in FIG.
  • the optical detector 5 comprises, in a modification of the embodiment shown in Fig. 1, an image-recording camera 17, the pixels of a grasp square or rectangular area 20 on the surface.
  • the illumination device 11 comprises a plurality of fluorescent tubes 13 configured in accordance with the exemplary embodiment shown in FIG. 1, which are also arranged to illuminate the surface 31 of the substrate 3, in particular the surface area 20 covered by the pixels, under oblique incidence of light Achieve dark field illumination.
  • the light source points are arranged along the fluorescent tubes so that light falls from at least two different directions of incidence on each of the substrate regions, the directions of incidence for each of the surface regions within the region 20 detected by the respective pixels being at an angle ⁇ of at least 45 °, preferably at least 90 °, more preferably at least 120 °.
  • the thin glass substrate 3 is guided along a feed direction 100 by means of a feed device, not shown, so that the substrate 3 is checked its length.
  • FIGS. 1 and 2 can be arranged side by side and transverse to the feed direction 33 in the embodiments shown in FIGS. 1 and 2 also several optical detectors.
  • an arrangement with a plurality of transverse to the feed direction optical detectors, which detect the substrate in its entire width across the feed direction, in particular. Preferred, in particular for wide substrates 3 in order to check their surface with high resolution can.
  • Fig. 3A and 3B parts of developments of inventive devices.
  • 3A shows an optical detector 5 with a line scan camera 7, wherein the optical detector 5 is preceded by a 4F arrangement 25.
  • the 4F arrangement comprises two cylindrical lenses 26, 27, in whose common focal plane a diaphragm 30 is arranged.
  • the illumination device 1 1 with a collimated and focused fluorescent tube 13 is followed by a structure corresponding to a 4F arrangement.
  • Such lighting devices and optical detectors with subsequent or upstream 4F arrangement can be used for example in the embodiments shown in FIG. 1 or 2.
  • the 4F arrangement 25 can effect a filtering of structure sizes which do not correspond to the structure size of the defects to be detected.
  • FIG. 4 shows a further exemplary embodiment of a device 1 according to the invention for detecting defects. This embodiment of the
  • the invention is based on phase contrast detection of defects, such as, in particular, scratches on the surface 31 of a thin glass substrate for TFT displays.
  • the basic structure is similar to the example shown in FIG. 1, however, the optical detector is constructed so that its optical axis lies in the light beam of the illumination arrangement reflected by the surface 31.
  • a slit diaphragm and a cylindrical lens is arranged, which focuses the light of the slit diaphragm 30 onto the substrate surface 31.
  • a further cylindrical lens 36 and a phase plate 38 having a linear light-attenuating region 39 are arranged in front of the line camera 7 of the optical detector 5.
  • the phase plate 38 is arranged so that the directly reflected light is attenuated by the line-shaped region 39.
  • the scattered light then has a direction deviating from the mirror beam and passes laterally past the line-shaped attenuating region 39 of the plate 38 into the line scan camera. On the respective pixels of the line scan camera 7 there is then an interference of the scattered with the attenuated direct light beam, so that defects due to the occurring
  • any arbitrary longitudinal portion of the aperture 30 forms again a light source point, so that each illuminated through the slot of the aperture 30 surface area is illuminated from several different directions.
  • the directions of incidence include an angle of at least 45 °, preferably of at least 90 °, particularly preferably of at least 120 °.
  • advantageously polarized light can also be used. Is, as measured in these embodiments in reflection, it offers It is also intended to use a lighting device 11 which emits s-polarized light with respect to the surface 31. Thus, the reflection is suppressed at error-free surface areas and achieved an improved signal-to-background ratio.
  • the illumination device 11 can then be advantageously arranged so that the light falls in or around the Brewster angle on the surface.
  • the lighting devices on the side 31 opposite side 32 of the substrate 3 can be arranged so that the light is not reflected, but is transmitted through the substrate 3.
  • the position of the illumination adjustment 11 is mirrored in each case on the substrate 3 with respect to the position shown in FIGS. 1, 2, 4.
  • the areas illuminated by the illumination device linear areas can be kept so narrow by means of appropriate collimation and / or focusing at oblique incidence that in the field detected by the line camera 20, or in the image field only one of both main surfaces, so one of the surfaces 31, 32 is illuminated.
  • Such an arrangement is outlined in Fig. 5, which illustrates the beam path according to this embodiment of the invention.
  • the arrangement of the optical detector 5 and the illumination device, not shown here, can correspond, for example, to the example shown in FIG.
  • the obliquely incident light beam 40 illuminates a region 41 on the surface 31 and a region 42 on the opposite surface 32.
  • the refraction of the light beam was not considered in the illustration.
  • the one of the Line detector 7 of the optical detector 5 detected area 20 is within the range 41, but outside the range 42. Accordingly, in the field of view of the camera 7 only one of the two. Illuminated surfaces. This is particularly useful because in this way signals due to stray light from defects on the surface 32 are suppressed.
  • a substrate 3 for the manufacture of TFT displays may still be used if there are no scratches on the coating side, although there may possibly be a scratch on the opposite side which would cause the coatings to be contaminated but optically completely inconspicuous is. By an arrangement, as shown in FIG. 5, therefore, the committee ⁇ can be considerably reduced.
  • a light source that emits light at a wavelength at which the workpiece transmits only little, in particular a transmission less than 50%, preferably less than 25%, most preferably less than 15%.
  • an optical detector 5 as shown in FIG. 5 can be provided with a polarizer 45 which transmits the light essentially perpendicular to the polarization of the reflected light from the substrate 3 polarized. Accordingly, using s-polarized light, one would adjust the polarizer so that reflected s-polarized light is blocked by the polarizer 45.
  • FIG. 6 shows a further variant of the example shown in FIG. 1.
  • a laser in particular a laser bar 50, for example a laser diode array with a plurality of linearly arranged in the direction parallel to the surface 31 laser diodes used.
  • the laser diode array may comprise at least one FAC, and preferably additionally at least one SAC lens, which generate at least one focus on the workpiece.
  • a phase framer scrambler may additionally be provided.
  • the "laser diode array may continue to adjust the longitudinal coherence at multiple longitudinal modes defined emit and / or desirable to define the longitudinal coherence properties notedzeitgepulst be operated.
  • the laser is a. corresponding jet-forming device downstream.
  • the illumination device 11 comprises holographic optical elements for defining a plurality of foci on the substrate.
  • the holographic optical element comprises a phase hologram.
  • a phase hologram plate 52 is disposed in front of the laser bar 50.
  • the phase hologram can advantageously be produced by structured deposition of vapor-deposited glass on a glass plate as a refractive element.
  • the light beams are also deflected and focused in the direction of the surface, so that again falls on each of the detected surface areas of the pixels light from different directions of incidence.
  • a glass plate can be used as a refractive element and a cylindrical lens.
  • the focusing in the lateral direction through the cylindrical lens and the focusing under different directions of incidence along the surface 31 can be effected by the phase hologram.
  • the illumination device also includes mirrors for beam shaping in this example.
  • a faceted mirror 54 with concave facets is provided which also serves to define a plurality of foci on the workpiece. This is arranged in the mirror beam so that the light is just reflected back to increase the light intensity on the illuminated surface area.
  • the mirror 54 may also be designed as a reflective element and support for holographic optical elements in order to reflect back light onto the detected surface area under different directions of incidence.
  • Fig. 7 shows a further embodiment of the invention, in which focused laser light is used for the detection of defects.
  • a lens 56 By means of a lens 56, a light beam 40 incident in the direction of the surface 32 of the thin-glass substrate 3 is focused so that the focus F lies within the substrate 3.
  • the light is focused by means of the lens 56 so that the focus has an extension of at most 200 microns, preferably at most 150 microns.
  • the aim is in particular a minimum extension of the focus in the range of about 50 microns to 100 microns.
  • a light source this is not shown in Fig. 7 for clarity - preferably a laser or a laser bar is used with a plurality of laser sources.
  • the detector 7 is disposed opposite to the light incident direction with respect to the substrate 3, so that the light scattered on the surface region 42 is detected by the detector 5 in transmission.
  • the detector is also arranged so that ' the area 41 on the detector 5 side facing 31 of the substrate 3 from Detector 5 is detected.
  • the optical axis 58 and the center beam 60 of the emergent light beam are also arranged at an acute angle ⁇ . This angle ⁇ is chosen so that the two areas 41, 42 do not overlap from the perspective of the detector 5. This is guaranteed if the angle ⁇ is:
  • n s is the refractive index of the substrate
  • b is the smallest dimension of the focus of the light beam
  • d is the thickness of the substrate.
  • the angle is more than 5 ° in the example shown. This lower limit is useful in order to avoid the detection of direct light from the peripheral areas of the light bundle during short focal length focusing.
  • the angle ⁇ is preferably at least 10 °, particularly preferably in the range of 10 ° to 30 °.
  • the regions 41, 42 at a given angle ⁇ in the projection move closer together as viewed from the detector 5 with a higher refractive index.
  • the regions 41, 42 for the detector can be detected separately.
  • the angle ⁇ here also corresponds to the light incident angle.
  • 71 and 71 comprise a line camera 7 with at least two lines of an embodiment of the invention, the optical detector. This is arranged with respect to the light source and the substrate 3 so that by means of the optics 63 of the detector 5 one of the rows 72 illuminated surface area 42 illuminated by the substrate on the substrate and the other line 71 the surface area illuminated by the light emerging from the substrate 41 recorded.
  • the arrangement with a measurement in transmission, or with a detector arranged opposite to the incident light beam, as shown in FIG. 7, is preferred to an arrangement in which the detector is arranged on the light incident side.
  • Fig. 7 allows observation of the surface portions 41, 42 at acute angles without causing problems with the arrangement of the light source and the detector 5 due to their dimensions. Such problems may arise in particular because of the preferred short focal length lens or lenses for focusing. Short focal length lenses are advantageous for producing small foci and thus high light intensities on the surfaces 31, 32 of the substrate. This is accompanied by the fact that the focusing lens 56 is to be arranged very close to the substrate surface 32 in order to achieve a position of the focus in the region of the substrate, preferably within the substrate. In addition, in many scattering structures, the forward scattering predominates, resulting in a better signal-to-noise ratio.
  • a configuration with a detector on the light incidence side also makes sense, for example if the signal of particularly small scattering structures is to be emphasized in comparison to the scatter signals of larger structures.
  • the intensities of forward and in this case the detector detected backward scattering are similar according to the intensity distribution of the Rayleigh scattering.
  • the detector can also include a signal amplifier to detect individual scattered photons with the highest sensitivity and security for the detection of the smallest defects.
  • a signal amplifier to detect individual scattered photons with the highest sensitivity and security for the detection of the smallest defects.
  • photomultipliers or multi-channel plates An exemplary embodiment is shown in FIG. 8. In the
  • Fig. 8 shown device 1 is a variant of the embodiment shown in Fig. 7. Again, the substrate portions 41, 42 are detected separately, so that it is distinguishable on which of the substrate sides 31, 32 is a defect. Unlike the in
  • photomultipliers 61, 62 are provided as components of the optical detector.
  • the optics 63 of the detector similar to the embodiment shown in Fig. 7 is formed so that each of one of the areas 41, 42 outgoing light beams are each focused on one of the photomultipliers 61, 62.
  • a scanning system with a scan Unit 65 is used with which the substrate 3 is scanned across the feed direction 33 by means of a laser beam.
  • the scanning unit 65 may be, for example, a Galvo scanner.
  • the entire substrate surface can be detected in this way.
  • the substrate is moved past the device 1 as in the examples shown in FIGS. 1 and '2 embodiments, along the feed direction 33.
  • the detected regions 41, 42 extending across the width transversely to the feed direction cover the entire surfaces 31, 32 or at least the regions of the thin-glass substrate to be checked.
  • an edge region of the substrate is not used for the production of display glass, this region does not necessarily have to be scanned with it.
  • this also applies to all other embodiments described here.
  • the detectors are arranged side by side along the width of the thin-glass substrate 3 perpendicular to the feed direction 33.
  • On the opposite side are several likewise juxtaposed lighting devices.
  • laser bars 50 are used for illumination.
  • Also shown on the side facing the detectors 5 side 31 of the substrate 3 each detected, transverse to the feed direction and along the entire width of the substrate 3 extending surface region 41, which is illuminated by the exiting, perpendicular to the feed direction 33 laser light.
  • an advancing and holding device In order to hold the substrate in its intended for the measurement position and to move the substrate along the feed direction, an advancing and holding device is provided.
  • this comprises rollers 55 on which the substrate 3 rests and is moved along the feed direction 33 by the rotation of the rollers.
  • a feed and holding device can also be provided in the other embodiments shown in order to keep the substrate in the intended position.
  • FIG. 10 shows a receptacle as can be obtained with an arrangement according to FIG. 7 or FIG. 8.
  • the image was not taken with a line camera or photomultipliers in conjunction with a scanning system, but with a matrix camera.
  • the image is shown in negative so that spots emitting stray light appear dark in FIG.
  • the illuminated strip-shaped surface regions 41, 42 are identified by dashed lines. In the surface area 41, some punctiform scattering structures can be recognized. These are due to particles 66 on the surface.
  • the opposite surface of the substrate 3 with the Illuminated area 42 has a fine scratch 67, which is clearly visible in the recording.
  • Concentration of scratches can be significantly reduced by sorting out as defective detected glasses.
  • concentration of scratches having a depth of 3 to 30 nanometers can be reduced to less than 5, preferably less than 3, more preferably less than 1 per square meter.
  • a production line, in particular for the production of TFT displays, which comprises such device according to the invention is thus able to quickly provide high-quality end products.
  • Manufacturing process can be controlled and optimized directly using the device for detecting defects.
  • German Patent and Trademark Office German patent application 10 2005 007715.3 entitled “Method and apparatus for detecting defects” fully made the content of the disclosure of this application.
  • the incorporated arrangement can be supplemented or combined with the device described below.
  • FIG. 11 shows a greatly simplified schematic representation of a flat glass substrate 3 from the side, on which a particle 162 and in which a scratch 162 is located.
  • the particle 162 which typically has a size of 0.5 ⁇ m and more, for example, up to 5 ⁇ m or more
  • Diameter both in viewing the " substrate from above with a bright field arrangement, as will be described in more detail below as well as when viewed with a dark field arrangement, as will also be described below, ' good to see.
  • Reference numeral 166 schematically indicates the optical signal, thus the image of a line-shaped defect, ie one
  • This optical signal has much less contrast in the bright field than in the dark field, and it can thus by subtracting the locally resolved optical signals of a bright field array of the locally resolved
  • Signals of a dark field arrangement of the particulate portion of the defects of scratches or bubbles in the glass can be distinguished.
  • the maximum or average intensity of the respective image can be normalized so that a value in the vicinity of the intensity zero value results for areas which are without defects.
  • FIG. 13 shows a schematic view of the device for detecting defects on and / or in workpieces 3.
  • Device of this embodiment in particular thin glass substrates 3 are checked for the presence of defects.
  • Typical defects can be detected, such as those caused by the manufacturing process, for example with downdraw thin glass, downdraw fusion thin glass, in particular overflow downdraw glass or float glass, as well as due to post-processing.
  • the device is suitable in a surprising manner and in a rapid testing of even very large substrates, 'as thin glass with a width of more than 1.8 m and / or a length of more than 2.0 m.
  • Polishing scratches on the surface 31 of the thin glass substrate 3, as in the surface treatment. remain behind or can arise.
  • radiation by means of a lighting device, in particular a laser 170 on directed the workpiece and at least partially influenced by the workpiece, in particular by the defect.
  • radiation is directed at least one light source, in particular a laser 170 to a workpiece 3 and is at least partially influenced by the workpiece 3, preferably by the defect 160, 162, 164, 166, wherein a first and a second optical signal generated which is detected in each case with an optical detector 180, 188 and wherein, v from these signals, a distinction of the defect is possible.
  • the first optical signal is a bright field signal which is obtained in a bright field arrangement.
  • This bright-field arrangement comprises a laser 170, of which at least one light beam passes through a beam splitter 172 onto a galvanometer scanner 182, which detects it
  • a galvanometer scanner does not necessarily mean a galvanically operated scanner, but generally a scanner for deflecting light rays.
  • the pivot point of the galvanometer scanner 182 from which the reflected laser beam propagates lies approximately in the left-side focal point of the converging lens 184, which is also referred to as F- ⁇ lens. Consequently, the right side 'emerging from the condenser lens 184, light rays are substantially parallel to each other and spread upon a pivotal movement of the mirror of the galvanometer scanner 182 on the surface 31 of the workpiece. 3
  • the laser beams pass through a beam splitter 174, which is substantially of the below-described detailed Bisfeldan order assigned '.
  • From the workpiece 3 is either from the front or. also reflects back light from the back and passes through the galavanometer scanner 182 in the beam splitter 172, from which this is directed into the photodetector 180.
  • the intensity or the spatially resolved contrast of this optical signal light reflected into the photodetector 180 depends on the surface contrast of the workpiece 3, which in the bright field is regularly higher for particles than for scratches or line-shaped defects.
  • the photodetector 180 preferably comprises a PIN diode or a photodiode with a high cutoff frequency.
  • the second optical signal is a dark field signal which is obtained in the dark field arrangement described below.
  • This dark-field arrangement comprises, in addition to the converging lens 184, the beam splitter 174, a line-shaped aperture 186, the further converging lens 178 and the photodetector 188.
  • the light reflected by the workpiece 3 is directed, after passing through the converging lens 184 through the beam splitter 174, not only into the bright field arrangement but also to the aperture 186 of the dark field arrangement.
  • the scattered light which contains the information of the second optical signal has a higher contrast with respect to the bright field optical signal, even with scratches or line-shaped defects, this means greater brightness differences.
  • the photodetector 188 is a photomultiplier.
  • the first optical signal includes spatially resolved information about defects containing particles
  • the second optical signal comprises spatially resolved information about defects including scratches, particles, glass defects.
  • Classification into particles or scratches or bubbles can thus be carried out by subtracting the two optical signals, wherein the
  • Subtraction of the optical signals takes place after their detection by detectors and conversion into electrical signals by electronic means in a downstream data processing system.
  • a dark-field illumination arrangement can be provided confocal to the optical axis of the optical detector 88, which is arranged in transmission.
  • the laser 170 or a laser diode array may emit for adjusting the longitudinal coherence to a defined plurality of longitudinal modes.
  • laser 170 or the laser diode array may be pulsed short-term.
  • the laser 170 may include a ⁇ Phasenfrontscrambler.
  • the concentration of scratches can be significantly reduced by sorting out glasses identified as defective.
  • the concentration of scratches with a depth of 3 to 30 nanometers can thus be reduced to less than 5, preferably less than 3, more preferably less than. 1 per square meter be lowered.
  • a production line, in particular for the production of TFT displays, which comprises such device according to the invention is thus able to quickly provide high-quality end products.

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Abstract

L'invention concerne un dispositif pour détecter des endroits défectueux, en particulier sur des surfaces de pièces à usiner. Selon l'invention, un rayonnement est dirigé vers une pièce à usiner, et est au moins partiellement modifié par la pièce à usiner, de préférence par l'endroit défectueux.
PCT/EP2006/001465 2005-02-18 2006-02-17 Procede et dispositif pour detecter et/ou classifier des endroits defectueux Ceased WO2006087213A2 (fr)

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DE200510007715 DE102005007715B4 (de) 2005-02-18 2005-02-18 Vorrichtung zur Erfassung von Fehlstellen und Verwendung der Vorrichtung
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DE102005062146 2005-12-22

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009021136A1 (de) * 2009-05-13 2010-12-16 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Regelvorrichtung
NL1039263C2 (nl) * 2011-12-23 2013-06-26 Zevenaar Elektronica & Sensoren B V Apparaat en werkwijze voor het tellen en bemeten van deeltjes.
CN109564170A (zh) * 2016-05-25 2019-04-02 康宁股份有限公司 检测玻璃的上表面上的颗粒的方法和装置以及照射入射光的方法
US10481053B2 (en) 2016-11-17 2019-11-19 Samsung Display Co., Ltd. Method for detecting defects of glass substrates
CN110672618A (zh) * 2019-09-25 2020-01-10 上海智觉光电科技有限公司 一种基于多角度光源的部件外观亮面检测系统及方法
CN114088665A (zh) * 2021-11-24 2022-02-25 广东医科大学 一种可用于透光率检测的光学测量装置
WO2023199265A1 (fr) * 2022-04-15 2023-10-19 3M Innovative Properties Company Systèmes et procédés d'inspection d'une surface de travail

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100890647B1 (ko) * 2008-06-27 2009-03-27 와이즈플래닛(주) 실린드리컬 렌즈 어레이 및 로드렌즈를 이용한 디스플레이검사장치
US8315453B2 (en) * 2010-07-27 2012-11-20 Applied Materials Israel, Ltd. Defect classification with optimized purity
KR101303602B1 (ko) * 2011-11-15 2013-09-11 주식회사 미르기술 비접촉식 발광다이오드 검사장치
WO2015000898A1 (fr) * 2013-07-01 2015-01-08 Sac Sirius Advanced Cybernetics Gmbh Procédé et dispositif de détection optique de la forme d'un objet et/ou de contrôle optique d'un objet
JP6476580B2 (ja) * 2014-04-21 2019-03-06 株式会社山梨技術工房 平板基板の表面状態検査装置及びそれを用いた平板基板の表面状態検査方法
KR101694379B1 (ko) 2014-12-29 2017-01-09 강우성 광학렌즈 자동 분류장치 및 이의 광학렌즈 자동분류 방법
KR101678169B1 (ko) * 2015-05-08 2016-11-21 주식회사 나노프로텍 초박판 투명기판 상면 이물 검출 장치
TWI604907B (zh) 2016-10-11 2017-11-11 財團法人工業技術研究院 雷射均勻加工裝置及其方法
US10681344B2 (en) * 2017-12-15 2020-06-09 Samsung Display Co., Ltd. System and method for mura detection on a display
TWI658266B (zh) * 2018-04-03 2019-05-01 中國鋼鐵股份有限公司 評測工輥表面品質之方法及系統
WO2021118838A1 (fr) * 2019-12-13 2021-06-17 Corning Incorporated Système et procédés de détection d'inclusion à base de laser
TWI807567B (zh) * 2021-12-30 2023-07-01 致茂電子股份有限公司 多功能標準校正片及光學檢測設備的檢測方法
KR102772754B1 (ko) * 2022-08-23 2025-02-24 한국로봇융합연구원 가중치를 고려한 레이저 스캐너 오염도 측정 장치 및 방법

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2078535A5 (fr) * 1970-02-16 1971-11-05 British Aircraft Corp Ltd
US3814946A (en) * 1972-12-04 1974-06-04 Asahi Glass Co Ltd Method of detecting defects in transparent and semitransparent bodies
FR2500630A1 (fr) * 1981-02-25 1982-08-27 Leser Jacques Procede pour la recherche des defauts des feuilles de verre et dispositif mettant en oeuvre ce procede
DE3534019A1 (de) * 1985-09-24 1987-04-02 Sick Optik Elektronik Erwin Optische bahnueberwachungsvorrichtung
EP0315697B1 (fr) * 1987-05-27 1993-08-04 Nippon Sheet Glass Co., Ltd. Detecteur discriminateur de defauts pour materiaux translucides en feuilles
DE3800053A1 (de) * 1988-01-04 1989-07-13 Sick Optik Elektronik Erwin Optische fehlerinspektionsvorrichtung
GB2219394B (en) * 1988-05-06 1992-09-16 Gersan Ets Sensing a narrow frequency band of radiation and examining objects or zones
DE3926349A1 (de) * 1989-08-09 1991-02-14 Sick Optik Elektronik Erwin Optische fehlerinspektionsvorrichtung
FR2697086B1 (fr) * 1992-10-20 1994-12-09 Thomson Csf Procédé et dispositif d'inspection de matériau transparent.
JPH10160683A (ja) 1996-11-29 1998-06-19 Matsushita Electric Ind Co Ltd 異物検査方法とその装置
GB9812091D0 (en) * 1998-06-05 1998-08-05 Glaverbel Defect detecting unit
CA2252308C (fr) * 1998-10-30 2005-01-04 Image Processing Systems, Inc. Systeme d'inspection de vitrage
KR20010055184A (ko) * 1999-12-09 2001-07-04 구자홍 유리기판의 패턴 검사용 광학 장치
US6731384B2 (en) * 2000-10-10 2004-05-04 Hitachi, Ltd. Apparatus for detecting foreign particle and defect and the same method
US6833913B1 (en) * 2002-02-26 2004-12-21 Kla-Tencor Technologies Corporation Apparatus and methods for optically inspecting a sample for anomalies
US6809808B2 (en) * 2002-03-22 2004-10-26 Applied Materials, Inc. Wafer defect detection system with traveling lens multi-beam scanner

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009021136A1 (de) * 2009-05-13 2010-12-16 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Regelvorrichtung
NL1039263C2 (nl) * 2011-12-23 2013-06-26 Zevenaar Elektronica & Sensoren B V Apparaat en werkwijze voor het tellen en bemeten van deeltjes.
CN109564170A (zh) * 2016-05-25 2019-04-02 康宁股份有限公司 检测玻璃的上表面上的颗粒的方法和装置以及照射入射光的方法
US10481053B2 (en) 2016-11-17 2019-11-19 Samsung Display Co., Ltd. Method for detecting defects of glass substrates
CN110672618A (zh) * 2019-09-25 2020-01-10 上海智觉光电科技有限公司 一种基于多角度光源的部件外观亮面检测系统及方法
CN114088665A (zh) * 2021-11-24 2022-02-25 广东医科大学 一种可用于透光率检测的光学测量装置
WO2023199265A1 (fr) * 2022-04-15 2023-10-19 3M Innovative Properties Company Systèmes et procédés d'inspection d'une surface de travail

Also Published As

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WO2006087213A3 (fr) 2007-03-29
KR101332786B1 (ko) 2013-11-25
TW200636230A (en) 2006-10-16

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