TWI708213B - Apparatus for detecting error of surface - Google Patents

Abstract

The present invention is a detection device for detecting defects on the surface of a measurement object, and relates to a defect detection device on the surface of a thin film, which is generated by generating light and incident the generated light on the surface of the measurement object and acquiring the incident light The pattern acquisition section of the pattern analyzes the acquired pattern and detects defects on the surface of the film, and the central axis of the illumination section is consistent with the central axis of the pattern acquisition section.

Description

Defect detection device on film surface

The present invention relates to a defect detection device for the surface of a thin film, and more particularly, to a defect detection device for irradiating a measurement object as a detection object with oblique illumination to detect defects generated on the surface of the measurement object.

Generally speaking, the types of defects that occur on the film surface of the object to be measured include protrusions, depressions, scratches, etc. In the past, various defect detection systems have been used to confirm the above-mentioned defects.

In order to detect defects, the above-mentioned inspection system installs ring-shaped illumination in the inspection device, and illuminates the surface of the object from various angles to measure the defects.

However, the above-mentioned defect detection can be applied to large-sized measuring objects, but for small-sized measuring objects, ring-shaped illumination cannot be installed because it cannot be installed.

In addition, for the measurement object whose surface forms a low inclination angle, the defects of the normal coaxial optical system technology in which light is incident in the vertical direction cannot be detected.

<Advanced Technical Literature>

<Patent Literature>

(Patent Document 1) Korean Patent Publication Publication No. 10-2007-0024393

In order to solve the above-mentioned problems, the present invention provides an illumination that has the same effect as the annular illumination instead of the ring illumination used to measure defects on the surface of the thin film of the measurement object of larger size.

Therefore, the present invention provides a detection device for detecting defects on the surface of a measurement object, which is provided by an illuminating unit that generates light and makes the generated light incident on the surface of the measurement object and a pattern acquisition portion that acquires a pattern generated by the incident light The obtained pattern is analyzed to detect defects on the surface of the film, and a light separation unit that separates the light generated by the illumination unit is installed between the illumination unit and the measurement object, so that the illumination unit When the generated light is incident on the surface of the measurement object, it can be incident obliquely, so that oblique light is incident from various angles, and defects of the measurement object can be clearly seen.

However, the object of the present invention is not limited to the above-mentioned objects, and those skilled in the technical field of the present invention should understand other objects that are not referred to.

In order to achieve the above-mentioned object, the present invention is used as a detection device for detecting defects on the surface of a measurement object by generating light and incident the generated light on the surface of the measurement object through an illumination unit and acquiring a pattern generated by the incident light The pattern acquisition section analyzes the acquired pattern to detect defects on the surface of the film, and an objective lens is formed on the upper part of the measurement object.

At this time, the vertical center axis passing through the center of the pattern acquisition section and the center of the objective lens and the horizontal center axis passing through the center of the illumination section meet between the pattern acquisition section and the objective lens, and there is also formed A beam splitter is arranged such that the reflecting surface is inclined at 45° by the point where the horizontal central axis meets the vertical central axis, and the light generated by the illuminating unit is reflected by the beam splitter and directed toward the measurement object The light reflected from the measurement object passes through the beam splitter and enters the pattern acquisition part.

In addition, a light separation unit is formed between the illumination unit and the measurement object, which separates the light generated by the illumination unit so that the light generated by the illumination unit can be incident on the surface of the measurement object. Inclined obliquely.

At this time, the light separation part is formed by a circular slit sheet, and the central axis of the circular slit sheet coincides with the central axis of the illuminating part.

In addition, the circular slit sheet is formed with a light passing portion through which the light of the illuminating part passes, and the light passing portion is formed on an outer periphery formed on the basis of the central axis of the circular slit sheet Between the surface and the inner peripheral surface, the inside of the inner peripheral surface and the outside of the outer peripheral surface form a clogging structure.

In addition, the wavefront of the light passing through the light passing portion forms a donut shape having an inner peripheral surface and an outer peripheral surface, and when the donut-shaped light enters the surface of the measurement object through the objective lens, the The diameter of the inner peripheral surface and the outer peripheral surface of the donut-shaped light gradually decreases and enters, so that the image of the donut-shaped light obliquely enters the surface of the measurement object.

In addition, an aperture is arranged between the measurement object and the pattern acquisition unit, and the aperture can adjust the aperture diameter through which light passes.

In addition, the illumination part is formed by a light source and an illumination lens, and the pattern acquisition part is formed by a camera and an imaging lens.

The features and benefits of the present invention will be more clarified by the following detailed description with reference to the drawings.

In addition, the terms and words used in this specification and the entitlement book cannot be interpreted in a lexicographical sense, and must be based on the principle that the inventor can appropriately define the concept of terms in order to explain his own invention in the most preferable way. , To explain in accordance with the meaning and concept of the technical idea of the present invention.

10: Object

11: camera

12: imaging lens

20: Objective

30: beam splitter

40: lighting

41: Illumination lens

110: Pattern Acquisition Department

111: camera

112: imaging lens

120: Objective

130: beam splitter

140: Aperture

200: Lighting Department

210: light source

220: Illumination lens

230: circular slit sheet

231: Optical separation part

240: Light Passing Department

241: inner circumference

242: Outer peripheral surface

300: Measured object

CA1: vertical center axis

CA2: Horizontal central axis

r1, r2: distance

L1, L2: length

Figure 1 is a schematic diagram showing a conventional defect detection device on the surface of a film; Figure 2 is a schematic diagram showing a detection device according to an embodiment of the present invention; Figure 3 is a schematic diagram showing a detection device according to an embodiment of the present invention; 4 is a schematic diagram showing the circular slit sheet formed in the detection device of the embodiment of the present invention; and Fig. 5 is a schematic diagram showing an aperture formed in the detection device of the embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In this process, the thickness of the line or the size of the constituent element illustrated in the drawing can be exaggeratedly shown for clear and convenient explanation.

In addition, the terms described later are terms defined according to the functions of the present invention, and they may be different according to the intention or convention of the user. Therefore, the above terms should be defined based on the content of the entire description.

Therefore, the following embodiments do not limit the scope of the patent application of the present invention, but are merely exemplary matters of the constituent elements proposed in the scope of the patent application of the present invention, and are included in the technical idea of the entire specification of the present invention, and Examples of constituent elements that include equivalents of constituent elements that can be substituted for the scope of the patent application all belong to the scope of patent application of the present invention.

The following describes in detail the defect detection device on the film surface of the preferred embodiment of the present invention with reference to the drawings, but the present invention is not limited to the following embodiments.

Fig. 1 is a schematic diagram showing a conventional defect detection device on a film surface; Fig. 2 is a schematic diagram showing a detection device according to an embodiment of the present invention; Fig. 3 is a schematic diagram showing a detection device according to an embodiment of the present invention; 4 is a schematic diagram showing the circular slit sheet formed in the detection device of the embodiment of the present invention; and FIG. 5 is a schematic diagram showing the aperture formed in the detection device of the embodiment of the present invention.

1, the conventionally used surface defect detection device is formed by a camera 11, an imaging lens 12, a beam splitter 30, an illumination lens 41, an illumination 40 from a light source, and an objective lens 20 located on the upper part of the object. Surface defects.

However, the light source of the detection device used in the past is only incident from the vertical direction, so it is not suitable for detecting defects with a lower angle.

In order to solve the above-mentioned problems, the defect detection device on the film surface of the present invention is formed as follows.

2 and 3, as a detection device for detecting defects on the surface of a measurement object, an illumination unit 200 that generates light and makes the generated light incident on the surface of the measurement object and a pattern acquisition unit 110 that acquires a pattern generated by the incident light To analyze the acquired pattern, detect defects on the surface of the film, and an objective lens is formed on the upper part of the measurement object.

At this time, the film surface is a film formed on the surface of the measurement object 300 to be detected, the illumination unit 200 is composed of a light source 210 and an illumination lens 220, and the pattern acquisition unit 110 is composed of a camera 111 and an imaging lens 112.

In addition, a vertical central axis CA1 passing through the center of the pattern acquiring unit 110 and the center of the objective lens 120 and a horizontal central axis CA2 passing through the center of the illuminating unit 200 intersect between the pattern acquiring unit 110 and the objective lens 120.

In addition, a beam splitter 130 is also formed, which passes through the intersection of the horizontal central axis CA2 and the vertical central axis CA1, and makes the reflection surface inclined by 45°. The light generated by the illuminating unit 200 is reflected from the beam splitter 130 to the measurement object 300 The light reflected from the measurement object 300 passes through the beam splitter 130 and enters the pattern acquisition unit 110.

At this time, a light separating section 231 is formed between the illuminating unit 200 and the measurement object 300, which separates the light generated by the illuminating unit 200 so that the light generated by the illuminating unit 200 enters the surface of the measurement object 300 obliquely Injection.

The light separation part 231 is composed of a circular slit sheet 230, and the central axis of the circular slit sheet 230 coincides with the central axis of the illumination unit 200.

In addition, the circular slit sheet 230 is formed with a light passing portion 240 that allows the light of the illuminating unit 200 to pass. The light passing portion 240 is located on the outer peripheral surface 242 and the inner peripheral surface formed based on the central axis of the circular slit sheet 230. Between 241, the inner side of the inner circumferential surface 241 and the outer side of the outer circumferential surface 242 form a clogging structure.

At this time, the size of the light separation part 231 can be adjusted.

The distance r1 of the light separation part and the length L1 of the circular slit formed in FIG. 2 are different from the distance r2 of the light separation part and the length L2 of the circular slit illustrated in FIG. 3.

At this time, the distances r1 and r2 of the light splitting part differ according to the lengths L1 and L2 of the circular slit sheet. With the difference in the distances r1 and r2 of the light splitting part, the light incident on the objective lens 120 is reflected by the beam splitter 130 The slope is different.

Therefore, by adjusting the distance length of the light separating portion 231, the angle of the light source incident on the measuring object 300 through the illumination lens 220 is formed differently, and the surface of the film can be observed from various angles to accurately measure the surface of the film. defect.

In addition, if the circular slit sheet 230 is removed from the defect detection device on the film surface, it can be used for coaxial illumination. If the circular slit sheet 230 is formed, it can be used for oblique illumination, and it can be used for coaxial illumination or oblique illumination as needed. .

4, the wavefront of the light passing through the light passage portion 240 forms a donut shape having an inner peripheral surface 241 and an outer peripheral surface 242, and the donut-shaped light passes through the objective lens 120 toward the surface of the measurement object 300 When incident, the inner peripheral surface 241 and the outer peripheral surface 242 of the donut-shaped light gradually decrease in diameter and enter, so that the image of the donut-shaped light enters the surface of the measurement object 300 obliquely.

In addition, by adjusting the distance length of the light separating portion 231, the sizes of the inner peripheral surface 241 and the outer peripheral surface 242 are changed, and the amount of the light source passing through the light passing portion 240 can be adjusted.

In addition, an aperture 140 is arranged between the measurement object 300 and the pattern acquisition unit 110, and the aperture 140 can adjust the aperture of the aperture 140 through which light passes.

5, by adjusting the size of the aperture 140 to change the depth of focus, it is possible to adjust the blur or sharpness of the object.

At this time, the smaller the size of the aperture 140, the deeper the focal depth.

Thus, by adjusting the size and angle of the aperture 140 and the inclination angle by the defect detection device on the film surface of the present invention, the defects formed on the surface of the measurement object can be detected more accurately and finely.

The present invention has been explained in detail through detailed embodiments above, but it is only for explaining the present invention in detail, and the present invention is not limited thereto. Those with ordinary knowledge in the technical field to which the present invention belongs can be within the scope of the technical idea of the present invention. Change or improve it.

Simple modifications to changes of the present invention belong to the scope of the present invention, and the detailed protection scope of the present invention will be more clarified by referring to the appended patent scope.

The beneficial effects of the present invention are:

According to the present invention as described above, there is an effect that when detecting a defect formed on the surface of the measurement object, the light generated from the illuminating unit is incident obliquely, and the defect formed on the surface of the measurement object can be detected.

In addition, it is possible to freely adjust the length of the light separation portion in which the light generated from the illuminating unit obliquely enters the measurement object, so that the light can be incident at various angles.

In addition, an aperture that changes the depth of focus according to the size is also formed, so that the blur or sharpness of the object can be adjusted, the size and angle of the aperture and the tilt angle can be adjusted, and the defects formed on the surface of the measurement object can be detected more clearly and precisely.

110: Pattern Acquisition Department

111: camera

112: imaging lens

120: Objective

130: beam splitter

140: Aperture

200: Lighting Department

210: light source

220: Illumination lens

230: circular slit sheet

231: Optical separation part

300: Measured object

CA1: vertical center axis

CA2: Horizontal central axis

Claims (6)

A defect detection device on the surface of a thin film, which is a detection device for detecting defects on the surface of a measuring object, comprising: an illuminating part to generate light and incident the generated light on the surface of the measuring object; and a pattern acquisition part to acquire A pattern generated by incident light, the pattern obtained is analyzed to detect defects on the surface of a thin film; an objective lens is formed on the upper part of the measurement object; and a light separation part is between the illumination part and the measurement object , Which separates the light generated by the illuminating unit so that the light generated by the illuminating unit can be incident obliquely when incident on the surface of the measurement object. The device for detecting defects on the surface of the film as described in claim 1, wherein a vertical central axis passing through the center of the pattern acquisition part and the center of the objective lens and a horizontal central axis passing through the center of the illuminating part are in the The pattern acquisition part intersects the objective lens, and the defect detection device on the surface of the film further includes a beam splitter configured to incline a reflective surface by 45° through the intersection of the horizontal central axis and the vertical central axis. The light generated by the illumination unit is reflected by the beam splitter and enters the surface of the measurement object, and the light reflected from the measurement object passes through the beam splitter and enters the pattern acquisition unit. The device for detecting defects on the surface of the film as described in the first item of the scope of patent application, wherein the light separating portion is formed by a circular slit sheet, and the central axis of the circular slit sheet is consistent with the central axis of the illuminating portion. In the device for detecting defects on the surface of a film as described in the scope of the patent application, wherein a light passing portion for passing the light of the illuminating part is formed in the circular slit sheet, and the light passing portion is formed in the Between an outer circumferential surface and an inner circumferential surface formed on the basis of the central axis of the circular slit piece, the inner side of the inner circumferential surface and the outer side of the outer circumferential surface form a clogging structure. The device for detecting defects on the surface of a thin film as described in any one of items 1 to 4 of the scope of the patent application, wherein an aperture is arranged between the measuring object and the pattern acquisition part, and the aperture can be adjusted to allow light to pass The aperture of one aperture. The device for detecting defects on the surface of the film as described in the first item of the scope of patent application, wherein the illuminating part is formed by a light source and an illuminating lens, and the pattern acquiring part is formed by a camera and an imaging lens.

Images