KR-20260062245-A - OPTICAL COHERENCE TOMOGRAPHY APPARATUS AND METHOD FOR INSPECTING DISPLAY DEVICE USING THE SAME

Abstract

An optical coherence tomography device comprises a source that emits source light, a splitter that splits the source light into a first-1 light and a first-2 light, a reference unit including a mirror that reflects the incident first-1 light to the splitter, a sample unit that inspects a display panel using the incident first-2 light and then reflects the first-2 light reflected from the display panel back to the splitter, a detector that converts an interference signal generated by combining the first-1 light reflected from the splitter and the reflected first-2 light into an electrical signal, and a processing unit that receives the electrical signal received from the detector and generates a tomographic image, wherein the speed at which the sample unit inspects the display panel may be variable.

Inventors

• 황태진
• 전만식
• 한상엽
• 정흥우
• 정기훈

Assignees

• 삼성디스플레이 주식회사
• 경북대학교 산학협력단

Dates

Publication Date

20260507

Application Date

20241028

Claims (20)

1. Source emitting source light; A splitter that divides the above source light into 1-1 light and 1-2 light; A reference section including a mirror that reflects the incident first-1 light to the splitter; A sample unit that inspects a display panel using the incident first and second light, and then reflects the first and second light reflected from the display panel back to a splitter; A detector that converts an interference signal generated by combining the first-1 light reflected from the splitter and the first-2 light reflected from the splitter into an electrical signal; and It includes a processing unit that receives an electrical signal received from the detector and generates a tomographic image, An optical coherence tomography device in which the speed at which the above sample unit inspects the above display panel is variable.
2. In Article 1, The above source is, Optical coherence tomography device for a display device comprising a variable light source that emits source light having different wavelengths over time.
3. In Article 1, The above reference unit is, A first collimator that adjusts the emitted first-1 light to be parallel to each other; A lens for correcting the first-1 light incident from the first collimator; and An optical coherence tomography device further comprising a first circulator that controls the first-1 light reflected from the mirror to be directed toward the splitter.
4. In Article 1, The above sample group is, A second collimator that adjusts the emitted first and second lights to be parallel; A scanning unit that inspects holes defined in the display panel using the first and second light; and An optical coherence tomography device comprising a second circulator that controls the first and second light scattered from the above-mentioned scanning unit to be directed toward the splitter.
5. In Article 4, The above scanning unit is, A rotating mirror that rotates around a rotation axis parallel to the first direction; A stage on which the above-mentioned display panel is positioned and which moves back and forth in the above-mentioned first direction; and An optical coherence tomography device comprising the above-mentioned rotating mirror and a condensing mirror disposed on the above-mentioned stage.
6. In Article 5, An optical coherence tomography device in which the area of the display panel irradiated with the first and second light is defined as inspection points, and the inspection points are arranged in a circular pattern on the area overlapping with the hole.
7. In Article 6, An optical coherence tomography device in which the number of inspection points surrounding the hole once in an area adjacent to the center of the hole is greater than the number of inspection points surrounding the hole once in an area spaced apart from the center of the hole.
8. In Article 6, An optical coherence tomography device in which the time taken for inspection points to surround the center of the hole once in an area adjacent to the center of the hole is longer than the time taken to surround the hole once in an area spaced apart from the center of the hole.
9. In Article 8, An optical coherence tomography device in which the rotation speed of the rotating mirror and the movement speed of the stage become slower as the above inspection points become closer to the center of the above hole.
10. Step of emitting source light from the source; A step of dividing the above source light into a splitter into a first-1 light and a first-2 light; A step of causing the above-mentioned first-1 light to be incident on a reference end, and the mirror of the reference end reflecting the first-1 light toward a splitter; A step of causing the first and second light to be incident on a sample section in which a display panel is placed, and emitting the first and second light scattered by the display panel toward a splitter; A step of combining the first-1 light reflected from the splitter and the first-2 light scattered to form an interference pattern; and The method includes the step of transmitting the above interference pattern to a detector and converting it into an electrical signal, A method for inspecting a display device in which the portion of the display panel irradiated with the first and second light is defined as inspection points, the inspection points are arranged in a plurality of circles, and the speed at which the inspection points are arranged is variable.
11. In Article 10, The above inspection points overlap the holes defined in the above display panel, and A method for inspecting a display device in which the arrangement speed of the inspection points in an area adjacent to the center of the hole is slower than the arrangement speed of the inspection points in an area spaced apart from the center of the hole.
12. In Article 11, The above source is, A method for inspecting a display device comprising a variable light source that emits source light having different wavelengths over time.
13. In Article 11, The above reference unit is, A first collimator that adjusts the emitted first-1 light to be parallel; A lens for correcting the first-1 light incident from the first collimator; and A display device inspection method further comprising a first circulator that controls the first-1 light reflected from the mirror to be directed toward the splitter.
14. In Article 13, The above sample group is, A second collimator that adjusts the emitted first and second lights to be parallel; A scanning unit that scans holes defined in the display panel using the first and second lights; and A method for inspecting a display device comprising a second circulator that controls the first and second light scattered from the above-mentioned scanning unit to be directed toward the splitter.
15. In Article 14, The above scanning unit is, A rotating mirror that rotates around a rotation axis parallel to the first direction to reflect the inspection points of the first and second lights that overlap with the hole, so as to be arranged in a second direction intersecting the first direction; A stage on which the above-mentioned display panel is positioned and which moves back and forth in the above-mentioned second direction; and A method for inspecting a display device comprising the above-mentioned rotating mirror and a light-concentrating mirror placed on the above-mentioned stage.
16. In Article 15, A method for inspecting a display device in which the rotation of the rotating mirror and the movement of the stage are operated simultaneously when the first and second light is irradiated onto the display panel.
17. In Article 15, The time taken for the inspection points to be arranged in a circle once in an area adjacent to the center of the hole is defined as the first period, and The time taken for the inspection points to be arranged in a circular pattern in an area spaced apart from the center of the hole is defined as the second period, and The above first cycle is a display device inspection method that is larger than the above second cycle.
18. In Article 15, The above-mentioned rotating mirror rotates upon receiving an external electrical signal, and A display device inspection method in which the frequency of the electrical signal decreases as the above inspection points are closer to the center of the above hole.
19. In Article 15, The above stage rotates upon receiving an external electrical signal, and A method for inspecting a display device in which the frequency of the electrical signal decreases as the above inspection points are closer to the center of the above hole.
20. In Article 10, A method for inspecting a display device comprising the step of transmitting the electrical signal to a processing unit to generate a cross-sectional image of the electrical signal.

Description

Optical Coherence Tomography Apparatus and Method for Inspecting Display Device Using the Same The present invention relates to an optical coherence tomography device and a method for inspecting a display device using the same. Optical Coherence Tomography (OCT) is a technology that utilizes optical interference phenomena to image the internal structure of a sample in high resolution without contact. Recently, OCT technology is also being utilized for defect inspection of electronic components, such as semiconductors and displays. FIG. 1 is a schematic diagram of an optical coherence tomography device according to one embodiment of the present invention. FIG. 2 is a perspective view for explaining the scanning unit illustrated in FIG. 1. Figure 3 is a perspective view of a display device examined by the optical coherence tomography device shown in Figure 1. Figure 4 is an exploded perspective view of the display device shown in Figure 3. Figure 5 is a block diagram of the display device shown in Figure 3. FIG. 6a is a plan view of the display unit shown in FIG. 5. Figure 6b is a signal circuit diagram of any one of the pixels shown in Figure 6a. Figure 7 is a plan view illustrating a method for inspecting a hole using the optical coherence tomography device shown in Figure 1. FIG. 8 is a plan view illustrating the inspection of a hole according to a comparative example. Figure 9a is a graph showing the rotation of the rotating mirror shown in Figure 2 as a frequency. Figure 9b is a graph showing the movement of the support plate shown in Figure 2 as a frequency. FIG. 9c is a plan view of the part corresponding to the first region (A1) of FIG. 7. Fig. 9d is an image generated through the processing unit of Fig. 2. FIG. 10a is a graph showing the rotation as frequency according to a comparative example of a rotating mirror. FIG. 10b is a graph showing the movement of a support plate according to a comparative example as a frequency. FIG. 10c is a plan view illustrating inspection points arranged by the frequencies of FIG. 10a and FIG. 10b. Fig. 10d is an image generated through the processing unit of Fig. 2. FIG. 10e is an image generated using a frequency according to a comparative example. FIG. 10f is an enlarged plan view of the second region shown in FIG. 10d. In this specification, where a component (or region, layer, part, etc.) is described as being “on,” “connected,” or “joined” another component, it means that it may be directly placed/connected/joined on the other component, or that a third component may be placed between them. Identical reference numerals denote identical components. Additionally, in the drawings, the thicknesses, proportions, and dimensions of components are exaggerated for the effective illustration of the technical content. “And/or” includes all one or more combinations that the associated components may define. Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. A singular expression includes a plural expression unless the context clearly indicates otherwise. Additionally, terms such as “below,” “lower,” “above,” and “upper” are used to describe the relationships between the components depicted in the drawings. These terms are relative concepts and are described based on the directions indicated in the drawings. Terms such as "include" or "have" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Furthermore, terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an overly ideal or overly formal sense unless explicitly defined herein. Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of an optical coherence tomography (OCT) device according to one embodiment of the present invention. FIG. 2 is a perspective view for explaining a scanning unit (SCP) shown in FIG. 1. Referring to FIG. 1, an optical coherence tomography (OCT) device may include a source (SOU), a splitter (SPL), a reference unit (STP), a sample unit (S