KR20060095479A - Visual inspection apparatus and visual inspection method - Google Patents

Abstract

Provided are an appearance inspection apparatus capable of identifying pseudo defects, which are problem components such as a light source and an optical element, and actual defects of the substrate itself, and an appearance inspection method using the same. In the appearance inspection apparatus 1 which inspects the board | substrate 6 by observing the reflected light of the illumination light irradiated to the surface 6a of the board | substrate 6, the light source 2 and the direction of the light radiate | emitted from the light source 2 Optical axis or focal position by oscillating or bending at least one of optical elements such as the second mirror 3 and the first mirror 4 for deflecting the light, or the Fresnel lens 5 for focusing the deflected light By displacing, oscillates the pseudo defects appearing on the substrate 6 due to the problem component of the illumination optical system, thereby identifying the pseudo defects and the actual defects occurring on the substrate 6 itself.

Light source, optical element, substrate, visual inspection, defect, mirror, deflection, optical axis, focus, lens

Description

Appearance Inspection Device and Appearance Inspection Method {VISUAL INSPECTION APPARATUS AND VISUAL INSPECTION METHOD}

1 is a diagram showing an appearance inspection apparatus according to a first embodiment of the present invention.

2 is a diagram showing an appearance inspection apparatus according to a second embodiment of the present invention.

[Description of the code]

1 Appearance inspection device 2 Light source

3 Second reflection mirror (optical element) 4 First reflection mirror (optical element)

5 Focus Lens (Fresnel Lens) (Optical Element)

6 Substrate 6a Surface of the substrate

7 Board Holder 8 Observer

9 Device Enclosure 10 Rotation Drive Means (Drive Means)

11 Control panel 20 Appearance inspection device

21 drive means O2 optical axis

O3 optical axis 04 optical axis

A focus position B focus position

C focus position

[Patent Document 1] Japanese Patent Application Laid-Open No. 2000-97864

TECHNICAL FIELD This invention relates to the external appearance inspection apparatus and external appearance inspection method of a glass substrate used for a liquid crystal display etc.

In the inspection of the conventional liquid crystal glass substrate or the like, the surface of the substrate is irradiated with light, and the observer visually observes the optical change of the reflected light, and there are defects such as film stains, pinholes, etc. of the resist applied to the surface, and presence of dust. Check the back. In the appearance inspection apparatus used for this kind of inspection, a focal point such as a fresnel lens or the like, which focuses and irradiates the surface of the substrate, for example, a fresnel lens, to concentrate the light deflected by the mirror and a mirror for deflecting the light emitted from the light source There exists a lens and the substrate holder which hold | maintains a board | substrate so that the macro illumination light concentrated by the focus lens may be irradiated to the substrate surface (for example, refer patent document 1). In such an appearance inspection apparatus, since the macro illumination light irradiated on the surface of the substrate is reflected while generating minute scattered light at the defect portion, the observer can inspect the defect on the surface of the substrate by visually observing the diffusely reflected reflected light (scattered light).

However, in the conventional visual inspection apparatus, when problems such as unevenness, minute scratches, and dirt adhere to an optical element (lighting optical system) such as a lens or a mirror, illumination light clouded by this problem component is applied to the substrate surface. It is investigated. The observer visually observes the surface of the substrate to which the illumination light is irradiated and detects a defect on the surface of the substrate. Therefore, the observer can identify whether the change of light expressed on the surface of the substrate is caused by a defect of the substrate itself or a problem component of the illumination optical system. There was a problem that could not. For this reason, there existed a problem that the pseudo defect image (pseudo defect) resulting from the problem component of an illumination optical system was mistaken for the defect of the board | substrate itself.

In view of the above circumstances, an object of the present invention is to provide an appearance inspection apparatus capable of identifying pseudo defects caused by problem components such as a light source and an optical element and actual defects of the substrate itself, and an appearance inspection method using the same.

In order to achieve the above object, the present invention provides the following means.

The present invention is an appearance inspection apparatus for inspecting the substrate by observing the reflected light from the surface of the substrate, comprising: a substrate holding the substrate at an angle suitable for macro inspection with respect to the light source and the illumination light emitted from the light source; At least one optical element configured to form an illumination optical system together with a holder, the light source and capable of displacing an optical axis or a focal position of the illumination light emitted from the light source, and at least one of the light source or the at least one optical element. And a drive means for swinging the dog to displace the optical axis or the focal position.

Moreover, this invention is the external appearance inspection apparatus which test | inspects the said board | substrate by observing the reflected light from the surface of a board | substrate, WHEREIN: The board | substrate which hold | maintains the said board | substrate at an angle suitable for macro inspection with respect to a light source and the illumination light emitted from the said light source. A macro illumination optical system comprising a holder, a reflection mirror for deflecting the light source and the illumination light emitted from the light source toward the substrate, and a focus lens for concentrating the illumination light reflected by the reflection mirror and irradiating the surface of the substrate. And driving means for oscillating the plate-shaped optical element of the focus lens or the reflecting mirror to shift the optical axis or the focus position of the macro illumination optical system.

In addition, the present invention is the appearance of inspecting the defect on the substrate by irradiating the illumination light emitted from the light source to the surface of the substrate held by the substrate holder at a predetermined incidence angle and visually observing the reflected light from the surface of the substrate. In the inspection method, at least one of the at least one optical element capable of displacing the optical axis of the light source or the illumination light emitted from the light source is oscillated in a direction crossing the optical axis direction of the illumination light to the surface of the substrate By irradiating on, the pseudo defect image resulting from the illumination optical system composed of the light source and the at least one optical element is oscillated on the surface of the substrate, and the pseudo defect and the actual defect appearing fixed on the surface of the substrate are fixed. It is characterized by enabling identification.

In addition, the present invention is the appearance of inspecting the defect on the substrate by irradiating the illumination light emitted from the light source to the surface of the substrate held by the substrate holder at a predetermined incidence angle and visually observing the reflected light from the surface of the substrate. In the inspection method, at least one of the at least one optical element capable of displacing the focal position of the light source or the illumination light emitted from the light source is oscillated in the optical axis direction to displace the focal position of the illumination light on the surface of the substrate. By irradiating, the focus state of the pseudo defect image resulting from the illumination optical system which consists of the said light source and the said at least 1 optical element is changed on the surface of the said board | substrate, and the pseudo defect and the actual defect which appear fixed on the surface of the said board | substrate It is characterized by making it possible to identify.

Hereinafter, an appearance inspection apparatus and an appearance inspection method according to the first embodiment of the present invention will be described with reference to FIG. 1.

As shown in Fig. 1, the first embodiment of the present invention is an appearance inspection apparatus 1 used for inspection of, for example, a liquid crystal glass substrate, and the appearance inspection apparatus 1 is, for example, a metal halide. Light source 2, such as a lamp, the 1st mirror 4 (optical element) which deflects the light radiate | emitted from the light source 2 to the 2nd mirror (2nd reflection mirror) 3 side, and the 1st mirror ( The second mirror 3 (optical element) for deflecting the light deflected by the first reflective mirror 4 to the focal lens 5 side, and the light deflected by the second mirror 3 to concentrate the substrate 6. For example, the focal lens 5 (optical element) to irradiate the entire surface or a part of a large inspection area of the surface 6a of the optical lens 6 and the substrate 6 disposed under the focal lens 5 and subjected to inspection, for example It consists of the board | substrate holder 7 holding a glass substrate for flat panel displays (FPD). Here, the light source 2, the first mirror 4, the second mirror 3, the focusing lens 5, and the substrate holder 7 are provided by the observer 8 with the naked eye on the surface 6a of the substrate 6. It is accommodated in the rectangular box-shaped apparatus outer body 9 which opened a part of one side (front surface) 9a of the observer side so that it may be observed. Reference numeral 9b denotes other side surfaces (back surface, right side surface, left side surface) constituting the device outer body 9 other than the one side surface 9a that becomes the front surface.

The first mirror 4 is formed in a rectangular thin plate shape, is installed on the emission light axis of the light source 2 and is inclined so that the mirror surface 4a faces the second mirror 3 side and exits from the light source 2. The illumination light to be reflected is reflected (deflected) toward the second mirror 3 disposed above the device outer body 9. In addition, the first mirror 4 is equipped with rotation drive means 10 such as a motor, for example, and for operation of the drive switch 11a of the operation portion 11 provided on the opening side of the device outer body 9. Therefore, forward rotation and reverse rotation (swing) are repeatedly performed at the center of the axis line O1 of the rotation drive means 10 in a range of a predetermined rotation angle. For example, by periodically reciprocating (swinging) the first mirror 4 at several small ± angles on an axis intersecting with the optical axis of the illumination light, it is reflected by the second mirror 3 and reflected on the substrate 6. The optical axis O2 of the illumination light which is irradiated becomes periodically displaceable in the orthogonal direction of the optical axis O2. The luminous flux of illumination light fluctuates on the surface of the board | substrate 6 by periodic displacement (swing) of the optical axis O2 of this illumination light. Here, the periodic rotation of the first mirror 4 is done so as to rotate the optical axis O2 at a minute angle that can be displaced by about 10 mm to 100 mm from the surface 6a of the substrate 6, and the observer From the viewpoint of the inspection efficiency of (8), it is a periodic movement so that it may displace about 30 mm-70 mm at plane distance, More preferably, about 50 mm at plane distance.

The second mirror 3 is formed in a rectangular thin plate shape and is disposed on the reflected light axis of the first mirror 4 above the light source 2, and is inclined such that the mirror surface 3a faces the focus lens 5. It is installed. Moreover, the 2nd mirror 3 is rotatably supported by the rotating shaft 3b extended in parallel with the one side surface 9a of the observer 8 side of the apparatus outer body 9, This rotating shaft 3b Is connected to rotation drive means 12 such as a motor. The rotation drive means 12 controls the second mirror 3 in accordance with the operation of the operation unit 11 to irradiate the surface 6a of the substrate 6 of the illumination light irradiated through the focus lens 5. For changing the range, for example, the second mirror 3 is rotated at a large angle of ± 30 °.

The focus lens 5 is made of, for example, a Fresnel lens formed in a rectangular plate shape, and is for irradiating the surface 6a of the substrate 6 by concentrating the light reflected from the second mirror 3. In the present embodiment, the focusing lens 5 includes a first Fresnel lens for converting the diffused light emitted from the light source 2 into a parallel light beam, and a light beam disposed close to the first Fresnel lens to concentrate the parallel light beam. Although it is comprised by the 2nd Fresnel lens, it is also possible to comprise one Fresnel lens. Hereinafter, this focusing lens 5 will be referred to as a Fresnel lens.

The board | substrate holder 7 is formed in rectangular plate shape, and can support the board | substrate 6 by the adsorption means (not shown) in the upper surface 7a. Further, the substrate holder 7 is disposed below the Fresnel lens 5 so that the illumination light concentrated by the Fresnel lens 5 is irradiated onto the surface 6a of the substrate 6. In addition, the substrate holder 7 is rotatably supported by a rotating shaft 7b extending in parallel to the one side surface 9a of the observer 8 side of the device outer body 9. Rotation drive means 13, such as a motor, is connected to this rotation shaft 7b, and by the operation of the drive switch 11a of the operation part 11, the board | substrate holder 7 is suitable for macro inspection from a horizontal position under illumination light. Inverts for tilt or backside inspection at a predetermined tilt angle.

Next, the method of inspecting the board | substrate 6 using the external appearance inspection apparatus 1 which consists of said structure is demonstrated.

Initially, the substrate 6 is mounted and adsorbed and held at the reference position of the upper surface 7a of the substrate holder 7, the origin coordinates of the substrate 6 are acquired, and the substrate holder 7 is at a predetermined inclination angle. Raise up. Then, the illumination light emitted from the light source 2 is irradiated to the substrate 6 mounted on the substrate holder 7 via the first mirror 4, the second mirror 3, and the Fresnel lens 5. . As shown in FIG. 1, when the board | substrate 6 mounted in the board | substrate holder 7 is large, and the illumination light concentrated by the Fresnel lens 5 cannot irradiate the board | substrate 6 whole surface, a 2nd mirror (3) is rotationally driven, and the illumination light reflected by the 2nd mirror 3 is scanned on the board | substrate 6 in the up-down direction of the board | substrate 6 which produced | generated at the predetermined inclination-angle. The observer 8 observes the reflected light of the light irradiated onto the surface 6a of the substrate 6, and inspects the presence or absence of a defect on the surface 6a of the substrate 6. Here, when damage occurs, for example, on the surface 6a of the board | substrate 6, the irradiated illumination light is diffusely reflected in the defect, and looks different from other normal parts.

During this macro inspection, the observer 8 operates the joystick 11b of the operation unit 11 to rotate the rotation drive means 13 forward and backward, so that the substrate holder (at an inclination angle at which the defect on the substrate 6 is easily visible under illumination) is observed. 7) Rotate After setting the substrate holder 7 to an inclination angle suitable for the observation of the observer 8, the joystick 11b is moved back and forth to rock the substrate holder 7 back and forth, thereby allowing the surface 6a of the substrate 6 to be moved. It becomes possible to detect the defect which generate | occur | produced at satisfactorily.

When a defect is detected on the surface 6a of the substrate 6 by this visual observation, the observer 8 stops the fine movement of the substrate holder 7. In this step, the rotation driving means 10 mounted on the first mirror 4 is driven to periodically reciprocally rotate (slightly swing) the first mirror 4 within a predetermined angle range. By the periodic rocking motion of the first mirror 4, the optical axis O2 of the illumination light irradiated onto the surface 6a of the substrate 6 is driven by the rocking motion and is from the optical axis O3 to the optical axis O4. Displace within the range. The observer 8 observes whether the defect detected by visual observation according to the periodic displacement of this optical axis is moved or fixed on the surface 6a of the substrate 6. That is, if it is a practical defect which arose in the board | substrate 6 itself, even if the optical axis O2 of illumination light is displaced from optical axis O3 to optical axis O4, the position will not change, but the problem component of an illumination optical system (for example, For example, in the case of a pseudo defect projected onto the surface 6a of the substrate 6 by foreign matter adhering to the surface of the optical element, the pseudo defect is oscillated on the substrate 6 by displacement of the optical axis. Therefore, when the defect detected by visual observation is fluctuating periodically, it is judged that it is a pseudo defect by the problem component of an illumination optical system, and can identify that it is an actual defect on the board | substrate 6. As shown in FIG. On the other hand, if it is not driven by the periodic displacement of the optical axis and the defect detected by visual observation does not move, it is determined that the detected defect is an actual defect of the substrate 6 itself, for example, using a laser pointer or the like. To obtain (register) the position coordinates of the actual defect.

When the board | substrate 6 to be inspected is large and it does not irradiate light to the whole surface, and is inspecting by dividing an inspection range, the angle of the 2nd mirror 3 is adjusted and an illumination light is irradiated to each division range, The same operation as that described above is repeatedly performed to inspect the entire surface of the substrate 6.

Therefore, in the external appearance inspection apparatus 1 which consists of said structure, by providing the rotation drive means 10 in the 1st mirror 4 smaller than the 2nd mirror 3, the axis of the rotation drive means 10 is provided. (01) It is possible to periodically rotate the first mirror 4 reciprocally at a slight angle by periodically repeating the forward rotation and the reverse rotation (swing) about the center, and concentrated by the Fresnel lens 5 to The optical axis O2 of the illumination light irradiated to the surface 6a can be periodically displaced within the range from the optical axis O3 to the optical axis O4. Thereby, among the defects detected by visual observation, it is driven by the periodic displacement of the optical axis O2 and periodically fluctuates on the substrate 6 to cause the pseudo defects caused by the problem components of the illumination optical system and the actual occurrence of the substrate 6 itself. Defects can be identified.

According to the external appearance inspection method using the external appearance inspection apparatus 1 which consists of said structure, the pseudo defect resulting from the trouble component of the illumination optical system and the actual defect of the board | substrate 6 itself which cannot be performed by the conventional method are reliably ensured. It can identify and improve the detection precision of the defect in an external inspection.

By oscillating the illumination optical system in this manner, it is possible to reliably identify pseudo defects caused by the illumination optical system and actual defects on the substrate 6, so that only the actual defects on the substrate 6 can be detected, for example, The trouble of detailed observation of the defect using the microscope etc. which are performed in the next process can be reduced, and the time required for board | substrate inspection can be reduced.

In addition, this invention is not limited to said 1st Example, It can change suitably in the range which does not deviate from the meaning. For example, as a means for periodically displacing the optical axis O2 of the illumination light irradiated onto the surface 6a of the substrate 6 or the focal position of the illumination light, in addition to the first mirror 4, the light source 2, or the first What is necessary is just to oscillate at least one of the two mirrors 3, the lens arrange | positioned near the light source 2, and the optical element arrange | positioned at illumination optical systems, such as the Fresnel lens 5 and the like. For example, the periphery of the plate-shaped optical elements such as the first mirror 4, the second mirror 3, and the Fresnel lens 5 is periodically pressed to bend to displace the optical axis or the focus position A of the illumination light. Alternatively, the optical axis of the illumination light may be displaced by moving at least one optical element constituting the illumination optical system continuously or intermittently in one direction or the other in the plane crossing the optical axis O2. In addition, although each optical element was made to rock | flux periodically by the rotation drive means 10, if the pseudo defect which appears on the board | substrate 6 due to the illumination optical system can be recognized visually by the observer 8, it will periodically. It is not necessary to rock it, and it may be made to swing it irregularly. In the first embodiment, the first and second mirrors 4 and 3 are used to deflect the illumination light emitted from the light source 2, but without using the first mirror 4. It is good also as a structure which irradiates the 2nd mirror 3 with the illumination light from the light source 2 directly. In these configurations, by oscillating at least one optical element constituting the illumination optical system and providing driving means for displacing the optical axis of the illumination light irradiated onto the substrate 6 or displacing the focal position A of the illumination light, It is possible to identify whether a pseudo defect is due to a problem component of the illumination optical system.

Next, with reference to FIG. 2, the external appearance inspection apparatus and external appearance inspection method which concerns on the 2nd Example of this invention are demonstrated.

The second embodiment of the present invention, like the first embodiment shown in FIG. 1, relates to an appearance inspection apparatus 20 used for inspection of a glass substrate for FPD, for example. Here, about the structure similar to the appearance inspection apparatus 1 which concerns on 1st Example, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted. In addition, in FIG. 2, the form at the time of seeing the inside of the external appearance inspection apparatus 20 from the observer 8 (not shown in FIG. 2) is shown. In addition, in FIG. 2, the board | substrate 6 has shown the state rotated centering on the axis line O5 so that it may become predetermined angle of inclination (45 degrees-60 degrees) suitable for macro inspection.

Unlike the first embodiment, the appearance inspection apparatus 20 shown in FIG. 2 is not provided with a mirror for deflecting the optical axis of the light emitted from the light source 2. On the other hand, two Fresnel lenses 5 fixed at a predetermined angle to enable illumination of light to the surface 6a of the substrate 6, and two Fresnel lenses 5 for irradiating light to the respective Fresnel lenses 5 The light source 2 is provided. In addition, each light source 2 is provided opposite to the Fresnel lens 5, and is disposed at an upper position of the device outer body 9 than the Fresnel lens 5. The light source 2 is also equipped with drive means 21 such as a linear actuator, for example, and the light source 2 reciprocates in the X direction (optical axis direction) by this drive means 21. It is supposed to slow down periodically. And the drive means 21 is controlled by operation of the drive switch 11a (not shown in FIG. 2) of the operation part 11 shown in FIG. 1, for example. Here, the periodic fine movement of the light source 2 is performed so that the focal position of the Fresnel lens 5 is shifted, for example, about 50 mm to 150 mm on the optical axis O2 line, from the viewpoint of the inspection efficiency of the observer. Preferably, the light source 2 is periodically reciprocated along the line of the optical axis 02 so as to displace about 100 mm as the displacement distance of the focal position. Reference numeral 2b denotes a cover of the light source 2.

Hereinafter, the method of inspecting the board | substrate 6 using the external appearance inspection apparatus 20 which consists of said structure is demonstrated.

Light is emitted from each light source 2, and light is irradiated to the substrate 6 mounted on the substrate holder 7 via each Fresnel lens 5. Illumination light concentrated by two Fresnel lenses 5 is irradiated onto the substrate 6 mounted on the substrate holder 7. The focal positions of the illumination light by the Fresnel lens 5 when the drive means 21 attached to the light source 2 are not driven are the focal positions B, respectively.

Then, in the state in which the substrate holder 7 is rotationally driven at an inclination angle suitable for observation, the surface 6a of the substrate 6 is observed under illumination light, and each light source 2 when a defect is detected. The drive means 21 mounted in the drive unit is driven to periodically swing the light source 2 on the optical axis O2 line and to reciprocate in a small range. By the reciprocating movement of this light source 2, the focus position B of illumination light irradiated to the surface 6a of the board | substrate 6 displaces to the focal position C, maintaining the direction of the optical axis O2. The observer observes that, in accordance with the periodic displacement of the focal position C from this focal position B, the defects appearing on the substrate 6 are changed on the surface 6a of the substrate 6, for example, in small and large variations (magnification, reduction). Or if the focus state such as the change in sharpness is changing, or if there is little or no change at all. When a change is recognized, it is judged that it is a pseudo defect projected on the board | substrate 6 by the problem component of the optical element of the illumination optical system. On the other hand, when the defect detected by visual observation does not change on the surface 6a of the board | substrate 6, and is not driven by the reciprocating movement of the light source 2, the defect detected by this visual observation is the board | substrate 6 It is determined that the image is an actual defect, and the position coordinates of the actual defect are acquired (registered) using, for example, a laser pointer.

Therefore, in the external appearance inspection apparatus 20 which consists of the said structure, the illumination means concentrated by the Fresnel lens 5 by providing the drive means 21 in the light source 2, and repeating reciprocating movement periodically on an optical axis. The focal position of can be periodically displaced between B and C. Thereby, the pseudo defect by the problem component of the illumination optical system which changes and follows the periodic displacement of a focal position among the defect which appeared in the surface 6a of the board | substrate 6, and the board | substrate 6 itself which does not follow and does not change The actual defect of can be identified.

In addition, this invention is not limited to said 2nd Example, It can change suitably in the range which does not deviate from the meaning. For example, although the driving means 21 is provided in the light source 2 as a means for periodically displacing the focal position (focal length) of the light irradiated onto the surface 6a of the substrate 6, the light source 2 The lens 2a or Fresnel lens 5 in the optical axis (O2) to reciprocate to shift the focus position of the illumination light, or periodically curved the Fresnel lens (5) while maintaining the optical axis (O2) direction It is also possible to shift the focus position of the illumination light. In the second embodiment, the light source 2 and the Fresnel lens 5 are provided in plural, but the respective quantities are not particularly limited. In addition, a mirror for deflecting the illumination light emitted from the light source 2 may be provided, and the mirror may be reciprocated or bent in the optical axis direction to displace the focus position. Further, the second embodiment is not limited to periodically shifting the focus position of the illumination light by moving at least one optical element constituting the illumination optical system, and the observer identifies a pseudo defect due to a problem component of the illumination optical system. The focal position may be shifted as much as possible.

According to the appearance inspection apparatus which concerns on this invention, at least 1 of a light source and an optical element can be rocked | shifted, and an optical axis or a focal position can be displaced. Thereby, among the defects detected by visual observation, it is possible to identify pseudo defects projected on the substrate which is driven by the displacement of the optical axis or the focal position and the actual defects generated on the substrate itself.

Claims (10)

In the appearance inspection apparatus which inspects the said board | substrate by observing the reflected light from the surface of a board | substrate, Light Source, A substrate holder for holding the substrate at an angle suitable for macro inspection with respect to the illumination light emitted from the light source, At least one optical element that constitutes an illumination optical system together with the light source and capable of displacing an optical axis or focal position of the illumination light emitted from the light source, and Drive means for displacing the optical axis or the focal position by oscillating at least one of the light source or the one or more optical elements Appearance inspection device comprising a. The method of claim 1, And the driving means oscillates at least one of the light source or the one or more optical elements in a direction crossing the optical axis of the illumination light to displace the optical axis of the illumination optical system. The method of claim 1, And the driving means shifts the focal position by swinging at least one of the light source or the one or more optical elements in the direction of the optical axis. The method according to any one of claims 1 to 3, And the driving means periodically fine-tunes at least one of the light source and the one or more optical elements. In the appearance inspection apparatus which inspects the said board | substrate by observing the reflected light from the surface of a board | substrate, Light Source, A substrate holder for holding the substrate at an angle suitable for macro inspection with respect to the illumination light emitted from the light source, A macro illumination optical system comprising a reflection mirror for deflecting the light source and the illumination light emitted from the light source toward the substrate, and a focus lens for concentrating the illumination light reflected by the reflection mirror and irradiating the surface of the substrate; Drive means for oscillating the plate-shaped optical element of the focus lens or the reflecting mirror to shift the optical axis or the focal position of the macro illumination optical system Appearance inspection device comprising a. The method of claim 5, The reflecting mirror is disposed between the light source and the focus lens, and comprises a first reflecting mirror that refracts an optical axis of the macro illumination optical system and a second reflecting mirror larger than the first reflecting mirror, The driving means oscillates one of the first reflecting mirror and the second reflecting mirror. Appearance inspection apparatus, characterized in that. The method according to claim 5 or 6, And said driving means oscillates said reflection mirror within a range of a predetermined rotational angle such that the reflection angle of said illumination light is displaced. The method of claim 5, And the drive means is configured to periodically bend one of the plate-shaped optical elements to displace the focal position. In the external appearance inspection method which inspects the defect on the said board | substrate by irradiating the illumination light radiate | emitted from a light source with a predetermined incidence angle with respect to the surface of the board | substrate hold | maintained at the board | substrate holder, and visually observing the reflected light from the said board | substrate surface, Irradiating the surface of the substrate with the illumination light by oscillating at least one of the light source or one or more optical elements capable of displacing the optical axis of the illumination light emitted from the light source in a direction crossing the optical axis direction of the illumination light. And a pseudo defect image caused by the illumination optical system consisting of the one or more optical elements is oscillated on the surface of the substrate, so that the pseudo defect and the actual defect appearing fixed on the surface of the substrate can be identified. Letting Appearance inspection method. In the external appearance inspection method which inspects the defect on the said board | substrate by irradiating the illumination light radiate | emitted from a light source with a predetermined incidence angle with respect to the surface of the board | substrate hold | maintained at the board | substrate holder, and visually observing the reflected light from the said board | substrate surface, At least one of the light source or one or more optical elements capable of displacing the focal position of the illumination light emitted from the light source is oscillated in the optical axis direction to irradiate the surface of the substrate while displacing the focal position of the illumination light, thereby causing the light source and the The focal state of the pseudo defect caused by the illumination optical system composed of one or more optical elements is changed on the surface of the substrate, so that the pseudo defect and the actual defect appearing fixed on the surface of the substrate can be identified. Appearance inspection method.

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