JP4971456B2 - Glass substrate quality inspection apparatus and inspection method thereof - Google Patents

Description

  The present invention relates to a glass substrate quality inspection apparatus for inspecting whether or not a glass substrate has a waveform for forming a thin film transistor (TFT) and a color filter in a thin film transistor liquid crystal display (TFT-LCD), and its It relates to the inspection method.

  The thin film transistor liquid crystal display device is roughly composed of a lower glass substrate on which a thin film transistor is formed, an upper glass substrate on which a color filter is formed, and liquid crystal injected between the lower glass substrate and the upper glass substrate.

  In the case of a glass substrate for forming such a thin film transistor and a color filter, when a waveform phenomenon with a non-uniform thickness occurs on the surface, film deposition or etching is not uniformly formed on the glass substrate, and the thin film transistor liquid crystal An abnormality occurs in the hue expressed by the liquid crystal of the display device, that is, discoloration occurs, resulting in a product defect.

  Thus, conventionally, a general quality inspection is performed on the glass substrate before the glass substrate is placed in the process chamber and a process using plasma such as vapor deposition, etching, or sputtering is performed.

  However, the conventional waveform inspection on the surface of the glass substrate could not perform accurate observation because the observation results were different for each observer.

  As an example, a conventional technique for inspecting the presence or absence of waveform generation on a glass substrate irradiates the glass substrate with a light source in a state where the glass substrate is vertically set, and the glass substrate is slightly tilted in a state parallel to the light source. By doing so, a shadow of the glass substrate is generated on the screen located on the opposite side of the glass substrate.

  Next, a transmittance difference (or light phase difference) occurs between the portion where the waveform is generated and the portion where the waveform is not generated from the shadow projected on the screen, and a white or slightly black bent portion appears. The presence or absence of waveform generation is determined by the eyes of the person.

  However, since the above-mentioned waveform inspection is impossible in-situ inspection, it is necessary to perform 100% inspection, and the waveform inspection is directly determined by the operator's eyes, so the process time is long and the reliability of the waveform inspection is increased. There is a disadvantage that the performance is greatly reduced.

  Accordingly, the present invention has been devised to solve the conventional problems as described above, and the illumination of the illumination unit for inspecting the presence or absence of waveform generation is transmitted only to the glass substrate. An object is to provide a glass substrate quality inspection apparatus and inspection method therefor.

  When the glass substrate quality inspection device for achieving the above object is supplied to the process equipment via the transfer unit, whether the glass substrate is transferred is inspected for the occurrence of waveform by an in situ inspection method in real time, Alternatively, in configuring an inspection unit that checks the presence / absence of waveform generation in real time when the glass substrate stops, the inspection unit includes an illumination unit that emits illumination that is transmitted through the surface of the glass substrate, and the illumination unit A video processing unit that captures a shadow image of the surface of the glass substrate generated from the illumination that is transmitted through the glass substrate, and an inspection of whether the waveform is generated on the surface of the glass substrate by the shadow image captured from the video processing unit. And a control unit.

  As another example, the illumination unit is a xenon lamp.

  As another example, a slit that localizes the illumination direction only to the glass substrate is coupled in front of the illumination unit so that a shadow image of the substrate surface generated through the glass substrate appears more clearly. It is characterized by comprising.

  As another example, the illumination angle θ of illumination applied to only the glass substrate by the slit is in the range of 18 to 22 °.

  An inspection method realized by the glass substrate quality inspection apparatus includes a step of irradiating the glass substrate with illumination at a predetermined angle to acquire a shadow image on the surface of the glass substrate, and corrugating the acquired shadow image. A step of differentiating the waveform-shaped shadow image by a differentiation algorithm and dividing the waveform into equal intervals, and a boundary condition of a reference value for the flatness of the glass substrate in the shadow image divided at equal intervals by the differentiation A step of applying, a step of detecting presence / absence of an image that deviates from the applied boundary condition and determining waveform generation, and a step of selecting a waveform type when a waveform is generated according to the determination result, including.

  The present invention enables a camera to shoot a shadow image of a glass substrate surface more clearly, and further inspects the presence / absence of each waveform type accompanying the shadow image by a differential algorithm, thereby continuously from a transfer unit. In addition, the quality of the glass substrate that is transferred in real time is inspected in real time to improve the quality satisfaction of the product, and the time required for the quality inspection of the glass substrate is saved, continuous deposition, etching, sputtering For example, a process using plasma can be performed quickly.

It is a whole block diagram with respect to the quality inspection apparatus of the glass substrate which concerns on embodiment of this invention. It is a front view in the state where a slit was applied to an illumination part concerning an embodiment of the present invention. It is a plane schematic diagram of the state which test | inspects the quality of a glass substrate from the horizontal direction which concerns on embodiment of this invention. FIG. 5 is a waveform diagram of a streak-like waveform as a type of waveform inspected by the present invention. FIG. 5 is a waveform diagram of a waveform of a waveform inspected according to the present invention and having a thick band shape. FIG. 4 is a waveform diagram of a waveform of a waveform that is a type of waveform inspected by the present invention. It is a detection waveform figure by experiment which shows the state where the streak-like waveform generate | occur | produced in the glass substrate which concerns on embodiment of this invention. It is a detection waveform figure by the experiment which shows the state which the waveform of a band shape generate | occur | produced in the glass substrate which concerns on embodiment of this invention. It is a detected waveform figure by experiment which shows the state where the code-like waveform generate | occur | produced in the glass substrate which concerns on embodiment of this invention. It is a detection waveform figure by experiment which shows the state where the streak-like waveform and the band-like waveform occurred simultaneously on the glass substrate according to the embodiment of the present invention. It is a flowchart which shows the quality inspection method of the glass substrate which concerns on embodiment of this invention. It is a plane schematic diagram of the state which test | inspects the quality of a glass substrate from the vertical direction which concerns on other embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is an overall configuration diagram for a glass substrate quality inspection apparatus according to an embodiment of the present invention, and FIG. 2 is a front view of a state where a slit is applied to an illumination unit according to an embodiment of the present invention. These show the plane schematic of the state which test | inspects the quality of a glass substrate from the horizontal direction which concerns on embodiment of this invention.

  FIG. 4 is a waveform diagram of a streak-like waveform that is inspected according to the present invention, and FIG. 5 is a waveform diagram of a waveform that is inspected according to the present invention, and is a waveform diagram of a quadrant waveform. FIG. 6 is a waveform diagram of the waveform of the code-like waveform to be inspected according to the present invention.

  FIG. 7 is a detected waveform diagram based on an experiment showing a state in which a streak-like waveform is generated on the glass substrate according to the embodiment of the present invention, and FIG. 8 is a quadband-shaped waveform generated on the glass substrate according to the embodiment of the present invention. FIG. 9 is a detection waveform diagram based on an experiment showing a state in which a code-like waveform is generated on a glass substrate according to an embodiment of the present invention, and FIG. 10 is a diagram illustrating an implementation of the present invention. The detected waveform figure by experiment which shows the state in which the streak-like waveform and the band-like waveform generate | occur | produced simultaneously on the glass substrate which concerns on a form is shown.

  As shown in FIGS. 1 to 10, the organic substrate quality inspection apparatus according to the embodiment of the present invention includes respective inflows of process equipment using plasma such as vapor deposition, etching, and sputtering processes for manufacturing a thin film transistor liquid crystal display device. In front of the side gate valve, the presence or absence of waveform generation of the glass substrate 2 transferred by the transfer unit 1 made of rollers is inspected in real time by an in situ inspection method, or the presence or absence of waveform generation when the glass substrate 2 is stopped The inspection unit is for inspecting in real time, and includes an inspection unit including an illumination unit 10, a video processing unit 20, and a control unit 30.

  The illumination unit 10 is a xenon lamp that emits illumination that is transmitted through the surface of the glass substrate 2, and has a predetermined angle θ on the lower side of the transfer unit 1 configured by rollers so that the glass substrate 2 can be transferred. A slit 11 is provided in front of the glass substrate 2 to guide the illumination so that only the surface of the glass substrate 2 is irradiated.

  The image processing unit 20 is a CCD camera module, and the glass substrate 2 generated from the illumination transmitted through the surface of the glass substrate 2 when the illumination unit 10 performs illumination transmission on the surface of the glass substrate 2. It is configured above the transfer unit 1 so that a shadow image of the surface is taken.

  The control unit 30 controls the illumination unit 10 and the video processing unit 20, and after inputting the shadow video taken from the video processing unit 20, as shown in FIGS. The configuration is such that the presence / absence of the waveform generation on the surface of the glass substrate 2 and the type of the waveform are inspected by a differential algorithm, and the criteria for applying the boundary conditions S and S ′ for the flatness of the glass substrate 2 to the internal memory. The value is set and saved.

  The operation of the embodiment of the present invention configured as described above will be described with reference to the attached FIG. 11 showing the glass substrate quality inspection method together with the attached FIGS.

  First, the glass substrate 2 is transferred or stopped to process equipment using plasma such as vapor deposition, etching, and sputtering for manufacturing a thin film transistor liquid crystal display device through a multistage transfer unit 1 composed of rollers. .

  At this time, a predetermined irradiation angle (θ; 20 °) is provided at the lower end of the transfer unit 1, and illumination is performed from the illumination unit 10 of the xenon lamp to which the slit 11 is coupled in front of the illumination unit 10. Since the illumination is performed only on the surface of the glass substrate 2 by the slit 11, it is transmitted to the opposite surface.

  As a result, a shadow image appears by illumination transmitted through the upper surface of the glass substrate 2, and the shadow image is photographed by the image processing unit 20 located above the transfer unit 1, that is, a CCD camera, and is sent to the control unit 30. Is transmitted.

  Next, the control unit 30 converts the captured shadow image into a waveform, differentiates it with a differentiation algorithm and divides it into equal intervals, and calculates the flatness of the glass substrate 2 from the waveformd shadow image. By applying the boundary values S and S ′ of the reference value to the image, it is detected whether or not there is an image that deviates from the applied boundary conditions S and S ′, and the generation of the waveform is determined. The type will be selected.

  That is, the control unit 30 detects whether or not there is a portion that has deviated from the preset boundary conditions S and S ′ in the shadow image that is differentiated and divided at equal intervals, and then detects the detected boundary. The number of equal intervals is calculated in regions other than the conditions S and S ′, and as shown in FIGS. 4 to 6, the surface of the glass substrate 2 has a streak-like waveform (Streak Type Waveness), a square-band waveform (Thick Band Type Waveness) or chord waveform (Cord Waveness) is checked for occurrence.

  This will be described in more detail. First, as a test when a streak-like waveform is generated on the surface of the glass substrate 2, as shown in FIGS. 4 to 10, the control unit 30 is differentiated and divided into equal intervals. If the shadow image includes a portion that has deviated from the preset boundary conditions S and S ′, the control unit 30 counts equal intervals of the differentiated shadow image by deviating from the boundary conditions S and S ′. become.

  At this time, as shown in FIG. 4 and FIG. 7, when the width of the entire equal interval of the shadow image from which the boundary conditions S and S ′ are removed from the counted number is narrow, the controller 30 controls the surface of the glass substrate 2. This is detected as a streak-like waveform.

  Next, as shown in FIG. 5 and FIG. 8, when the entire equidistant width of the shadow image from which the boundary conditions S and S ′ are removed from the counted number is wide, the control unit 30 may It is detected that a square band waveform is generated.

  Next, as shown in FIG. 6 and FIG. 9, when the entire equal interval width of the shadow image that deviates the boundary conditions S and S ′ from the counted number has a repetition cycle, the control unit 30 is detected as a code-like waveform generated on the surface of the glass substrate 2.

  At this time, as shown in FIGS. 4, 5, and 10, the entire equal interval width of the shadow image that deviates from the boundary conditions S and S ′ from the counted number is distributed narrowly, or the entire equal interval When the phenomenon that the width is widely distributed appears at the same time, the control unit 30 detects that the streak-like waveform and the squiband-like waveform are generated on the surface of the glass substrate 2 at the same time.

  On the other hand, FIG. 12 is another embodiment of the present invention showing a schematic plan view in the case of inspecting the quality of the glass substrate from the vertical direction, which is a multistage transfer unit 1 comprising rollers for transferring the glass substrate 2. After removing the first stage, the removed unit is provided with the inspection unit 100 including the illumination unit 10, the image processing unit 20, and the control unit 30 from the vertical direction. It is possible to detect from the vertical direction.

  That is, according to the present invention, as shown in FIGS. 3 and 12, the presence / absence of waveform generation on the surface of the glass substrate 2 can be detected from the horizontal direction and the vertical direction, so that the quality inspection of the glass substrate 2 can be performed more precisely. It can be carried out.

  As described above, the same parts as those of the embodiment of the present invention are denoted by the same reference numerals, and the description thereof is omitted.

  According to the present invention, the shadow image of the glass substrate surface can be clearly captured by the camera, and the presence / absence of occurrence of each waveform type by the shadow image can be inspected more precisely by a differentiation algorithm.

DESCRIPTION OF SYMBOLS 1 Transfer unit 2 Glass substrate 10 Illumination part 11 Slit 20 Image processing part 30 Control part

Claims (1)

Illuminating the glass substrate at a predetermined angle to obtain a shadow image on the surface of the glass substrate; and corrugating the acquired shadow image;
Differentiating the waveform-shaped shadow image with a differentiation algorithm and dividing it into a predetermined interval;
Applying a boundary condition of a reference value for the flatness of the glass substrate to shadow images divided at equal intervals via the differentiation;
Detecting whether there is a video that deviates from the applied boundary condition and determining waveform generation;
A result of the determination, see contains the steps of selecting the waveform type when the waveform is generated, and
The selection of the waveform type is as follows:
A certain distance of the shadow from the video that has been divided by differentiating of escape from the boundary conditions to count,
If the width of the fixed interval within the waveform range of the shadow image transmitted through the upper surface of the glass substrate by the illumination of the shadow image that deviates from the boundary condition from the counted number is narrow, it is selected as a streak-like waveform ,
The selection of the waveform type is as follows:
A certain distance of the shadow from the video that has been divided by differentiating of escape from the boundary conditions to count,
If the width of a certain interval within the waveform range of the shadow image transmitted through the upper surface of the glass substrate by the illumination of the shadow image that deviates from the boundary condition from the counted number is wide, the waveform is selected as a band-like waveform , or ,
The selection of the waveform type is as follows:
A certain distance of the shadow from the video that has been divided by differentiating of escape from the boundary conditions to count,
If the width of a certain interval within the waveform range of the shadow image transmitted through the upper surface of the glass substrate by the illumination of the shadow image that deviates from the boundary condition from the counted number has a repetition period, the code-like waveform A glass substrate quality inspection method characterized by sorting as:

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