TWI586959B - Automatic appearance inspection device - Google Patents

Description

Automatic visual inspection device

The present invention relates to a technique for automatically inspecting a defect such as a circuit pattern formed on an inspection object such as a glass or a semiconductor wafer.

For example, a semiconductor device is formed by arranging a plurality of circuit patterns on a wafer and cutting them into individual pieces to be manufactured. Each of the circuit patterns is formed by laminating a plurality of layers in a wiring or film formation, and whether or not a defect such as a short circuit or a disconnection of a wiring or a foreign matter is mixed is inspected after the formation of the circuit pattern of each layer. (for example, Patent Document 1)

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-224303

In order to increase the number of manufacturing per unit time, the inspection device is also required to have a high throughput. Therefore, in order to shorten each The inspection time taken for one substrate, the speed of the mobile platform, or the configuration of a plurality of imaging units are conceivable. However, even if the mobile platform is speeded up, the time until the next image can be acquired after the acquisition of the image of the camera becomes a bottleneck, and there is still a limit to the speed.

Fig. 10 is a view showing a state in which a transfer data is displayed in time series by a photographing instruction through a photographing instruction in a time chart in the prior art. When the camera is instructed to shoot, it is in a state where the camera can be photographed (in the figure, it is described as "ON"). During this period, the flash is illuminated (indicated as ON in the figure), and the camera is finished (the image is turned OFF in the figure). In the case of a camera, the image data is transferred to an external device or a buffer memory. Cameras are often used with highly versatile cameras that are generally popular, but such cameras are capable of storing images that are not stored, or that are only one of the next images in the transfer of image data. Therefore, with the interval Td at which the image data can be continuously transferred, photographing is sequentially performed at the same interval T1. Therefore, at the time of continuous shooting, the interval T1 becomes a bottleneck for shortening the time.

On the other hand, in order to shorten the inspection time, a configuration in which a plurality of imaging units are arranged (for example, two circuit patterns are simultaneously acquired by two cameras) has been conceived. However, when the inspection object is small, the interval between the imaging units cannot be shortened. When a plurality of circuits cannot be taken at the same time, the time cannot be shortened as expected.

In addition, when there are a plurality of objective lenses having different imaging magnifications in response to a plurality of types, the number of lenses increases, which causes a cost increase. In order to match the inspection quality, it is necessary to correct the difference of the plurality of imaging units. Difference), there are also classes that are more factors that increase costs. question.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an automatic visual inspection apparatus in which the processing capability of a camera can be shortened without limitation.

In order to solve the above problems, the invention of the first aspect of the invention is an automatic visual inspection device, which is an inspection object inspection device for detecting a defect formed in a pattern of an inspection object, and includes: carrying the inspection object a table portion that scans the table portion in a predetermined direction; an illumination portion that illuminates the inspection object toward the inspection object; and light that is reflected by the illumination portion and reflected by the inspection object The light of the object to be inspected is a lens barrel portion that guides light as observation light, and an image capturing portion that is attached to the barrel portion and that images the observation light; and while the scanning platform portion is moved, the illumination unit is caused to emit light. a control unit for observing the image of the light; and an inspection unit for determining the quality of the image of the object to be inspected based on the pre-registered inspection condition, wherein the scanning platform unit includes the current position of the table portion The position measuring means includes a part of the observation light transmitted through the barrel portion, and the angle is changed In a part of the light branching means for reflecting, a plurality of the image capturing units are attached to the barrel portion so that light branched by the light branching means can be photographed, and the control unit includes: In each of the plurality of photographing units, the photographing function is switched to the photographable photographing unit in which the image data transfer is completed, and the photographing function is performed.

Since the apparatus of the above invention is used, the observation light is branched and can be simultaneously photographed by a plurality of photographing sections, and even one of the plurality of photographing sections by the flash light emission cannot be processed in the next one. The state of photography can also be photographed in another photography department.

The invention of the second aspect of the invention is an automatic visual inspection device, which is an inspection object inspection device that detects a defect formed in a pattern of an inspection object, and includes: a table portion that carries the inspection object; The table portion scans the scanning platform portion that moves in a predetermined direction; the illumination portion that illuminates the illumination object toward the inspection object; and the light that is reflected by the illumination portion and reflected by the inspection object or that transmits the inspection object a lens barrel portion that guides light as observation light, an imaging portion that is attached to the barrel portion and that images the observation light, and that causes the illumination unit to emit light while moving the scanning platform portion to control imaging of the observation light And an inspection unit that determines whether the image of the object to be inspected is imaged by the pre-registered inspection condition, and the scanning platform unit includes a position measuring device that measures a current position of the table portion, The barrel portion includes an angle or a direction for changing the aforementioned observation light and In the light reflecting means for reflecting, a plurality of the imaging units are attached to the barrel portion so that the light reflected by the light reflecting means can be captured, and the control unit includes: each of the images is changed in conjunction with the shooting. In the reflection direction of the light reflecting means, and among the plurality of imaging units, the image data is transferred to the photographable photographing unit after the end of the image data transfer, and the photographing function is performed.

Since the apparatus of the above invention is used, the light switching direction can be observed and any one of the plurality of imaging units can be photographed, and even one of the plurality of imaging units can be processed in conjunction with the flash illumination. It is impossible to perform the next shooting state, and it is also possible to switch the shooting direction and take another photography unit.

The invention of the third aspect of the invention is the automatic visual inspection device according to the second aspect of the invention, wherein the actuator unit is further provided with an actuator unit for changing the position or angle of the light reflecting means. The actuator unit drives the actuator unit in conjunction with the photographing to perform the photographing.

According to the apparatus of the above invention, the position or angle of the light reflecting means can be controlled by the actuator portion, and the displacement of the position or angle of the light reflecting means can be prevented.

The invention described in the fourth aspect of the patent application is the automatic visual inspection device described in claim 3, wherein the actuator portion is In the aforementioned photographing, the position or the angle of the light reflecting means is also in a moving state.

According to the apparatus of the above invention, the position or angle of the light reflecting means is continuously changed before and after the photographing, and the inertial force generated by the stationary or re-moving can be eliminated, and the time required for the bottleneck of continuous photographing can be reduced.

The invention of claim 5 is the automatic visual inspection device according to the fourth aspect of the invention, wherein the moving speed of the actuator unit in the photographing is slower than the moving speed in the non-photographing.

According to the apparatus of the above invention, the position or angle of the light reflecting means is continuously changed before and after the photographing, and the image blurring at the time of photographing can be reduced while reducing the inertial force caused by the stationary or re-moving.

The invention of claim 6 is the automatic visual inspection device according to any one of claims 3 to 5, wherein the actuator portion or the light reflecting means is mounted with the detection current position. The position detector or the angle detector that detects the current angle performs the aforementioned photographing based on the position detector or the information of the angle detector.

According to the apparatus of the above aspect of the invention, the angle of the observation light reflected by the light reflecting means in the lens barrel can be managed, and the inspection target area of the inspection object can be prevented from deviating from the visual field of the imaging unit.

The invention of claim 7, wherein the illumination unit that illuminates the illumination light is a flash unit that illuminates the flash, and the photographing is performed in the seventh aspect of the invention. It is performed by the light emission of the flash lamp.

According to the apparatus of the above aspect of the invention, since the flash of high illuminating energy can be relatively easily irradiated, the present invention can be applied even in the case where a camera used for photographing uses a low-cost camera having high versatility.

The processing power of the camera can be shortened without limitation.

The embodiment for carrying out the invention will be described with reference to the drawings. In the following description, the inspection object of the present invention will be described based on an example in which a plurality of circuit patterns are formed on the semiconductor wafer 10.

Fig. 1 is a perspective view showing an example of a mode embodying the present invention. Hereinafter, in each of the figures, the three axes of the orthogonal coordinate system are X, Y, and Z, and the XY plane is a horizontal plane, and the Z direction is a vertical direction. In particular, the Y direction is the inner side of the arrow direction, and the reverse direction is the front side, and the Z direction is the direction of the arrow, and the reverse direction is the lower side. Further, the rotation direction with the Z axis as the center of rotation is expressed in the θ direction.

The automatic visual inspection device 1 includes a transport unit 2 that is attached to the apparatus base 11 , a flash unit 3 that emits light toward the inspection object, and a lens barrel unit 4 that is attached to the apparatus base 11; The photographing unit 5 that observes the light guided by the barrel portion 4; the control unit 9. Each component is attached through an apparatus frame (not shown), a fixed bracket, or the like so as to be placed at the position shown in FIG.

The transport unit 2 includes a member that is mounted on the device base 11 The upper X-axis platform 21; the Y-axis platform 22 mounted on the X-axis platform 21; the rotating platform 23 mounted on the Y-axis platform 22; and the table portion 25 mounted on the rotating platform 23.

The X-axis stage 21 can move the Y-axis stage 22 mounted thereon in the X direction, and the Y-axis stage 22 can move the rotating platform 23 mounted thereon in the Y direction, and the rotating platform 23 can be mounted on the stage The portion 25 is rotated in the θ direction. Further, the X-axis stage 21, the Y-axis stage 22, and the rotating platform 23 constitute the scanning platform portion of the present invention.

The table portion 25 is formed with a groove or a hole on the surface, and the groove or hole is connected to the vacuum source via a switch control valve. The semiconductor wafer 10 carried on the stage portion 25 is held by the negative pressure adsorption so as not to be displaced in the movement of the stage portion 25.

The X-axis stage 21 includes an X-axis position detector, and can obtain current position information in the X direction of the Y-axis stage 22 mounted on the X-axis stage 21. Similarly, the Y-axis stage 22 includes a Y-axis position detector, and the current position information in the Y direction of the rotating platform 23 mounted on the Y-axis stage 22 can be obtained. Further, the rotating platform 23 includes a rotation angle detector, and can obtain current angle information in the θ direction of the table portion 25 attached to the rotating platform 23.

Since the transport unit 2 has the above configuration, the semiconductor wafer 10 placed on the stage portion 25 can be moved in the XY direction or rotated in the θ direction, and the scan can be moved in a predetermined direction. Moreover, the current position information and the rotation angle information in the XY direction of the table portion can be obtained.

The flash unit 3 includes a coaxial episcopic illumination 31 and an illumination light-emitting device 31s, which can be extremely short. Time causes a high amount of light to illuminate (so-called flash illuminating). The coaxial epi-illumination illumination 31 is attached to the barrel portion 4, which will be described later in detail, and can be passed through a half mirror or the like in the barrel portion 4 so that an optical path coaxial with the observation light is approximately perpendicular to the semiconductor wafer 10. Ground light.

Further, the flash unit 3 may be configured by the ring type illumination 33, the illumination light-emitting device 33s, the surface-emission type illumination 35, the illumination light-emitting device 35s, or the like, and may be used instead of or in combination with the coaxial epi-illumination device 31 and the illumination light-emitting device 31s. The ring type illumination 33 is attached to the outside of the barrel portion 4, and illuminates the semiconductor wafer 10 obliquely with illumination light.

The surface-emitting illumination 35 is embedded in the stage portion 25, and the illumination light is emitted upward from the bottom surface of the semiconductor wafer 10.

The barrel portion 4 is configured to be guided by light that is irradiated to the semiconductor wafer 10 by the flash unit 3 and that is reflected by or transmitted through the semiconductor wafer 10 as light.

The lens branching unit 4 includes a light branching means 45 in the middle of observing the path in which the light is guided, and allows a part of the observation light to be transmitted, and the angle is changed to partially reflect it. Further, the barrel portion 4 is preferably configured to include a photographic mirror 42, and is configured to change the direction of the observation light to guide light.

The optical branching means 45 can exemplify an optical element such as a half mirror or a beam splitter.

In the photographing unit 5, a plurality of cameras 51a and 51b are attached to the barrel portion 4, and each of the cameras 51a and 51b can image the light guided and branched. Further, the objective lenses 55a and 55b are attached to the barrel portion 4, and the observation light can be imaged at a predetermined observation magnification.

The cameras 51a and 51b can be exemplified by a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor), or a camera using another imaging element, and if the captured image is used as an image signal, It is sufficient if it is output to the control unit 9. Further, it is preferable that the cameras 51a and 51b are high-sensitivity photographers. According to this, even if the observation light 40v is branched into the two observation lights 45v1 and 45v2 by the light branching means 45, the amount of light is half as compared with the observation light 40v before the branching, and the image can be sufficiently captured. Alternatively, the sensitivity of the cameras 51a, 51b may be maintained, and the illuminating energy of the flash lamp may be increased to ensure the brightness of the observed light.

Fig. 2 is a system configuration diagram showing an example of a mode embodying the present invention. As shown in FIG. 2, each of the above-described transport unit 2, the flash unit 3, and the photographing unit 5 is connected to each device of the control unit 9.

The control unit 9 is connected to include a control computer 90, an information input means 91, an information output means 92, a warning means 93, an information recording means 94, and a machine control unit 95.

The control computer 90 can be exemplified by a numerical calculation unit equipped with a microcomputer, a personal computer, a work station, or the like. The information input means 91 can exemplify a keyboard or a mouse or a switch. The information output means 92 can exemplify an image display display or a lamp or the like.

The warning means 93 can exemplify a device such as a buzzer or a speaker, a lamp, or the like that can alert the operator. The information recording means 94 can be exemplified by a semiconductor recording medium such as a memory card or a data disk, a magnetic recording medium, a magneto-optical recording medium or the like. machine The controller control unit 95 can exemplify a programmable controller or a machine called a motion controller.

The video signals output from the cameras 51a and 51b are input to the control computer 90 via the image processing unit 96. The image processing unit 96 is generally referred to as a GPU (Graphic Processing Unit), and can be exemplified by a form of the outside of the control computer 90 and a form connected to the inside of the control computer 90. The image processing unit of the computer 90 or the like.

The observation image input to the image processing unit 96 can be judged by the control computer 90 (i.e., inspection) as will be described later in detail.

The machine control unit 95 is connected to the X-axis stage 21, the Y-axis stage 22, and the rotating platform 23. Further, the machine control unit 95 is connected to the illumination light-emitting devices 31s, 33s, and 35s of the flash unit 3. The manner of adjusting the amount of illumination of the illumination in the illumination lighting devices 31s, 33s, 35s may exemplify the manner of adjusting the applied voltage or current, or adjusting the application time of the voltage or current, according to the illumination command signal from the machine control unit 95, the flash The pre-set conditions are illuminated.

The machine control unit 95 is connected to another control device (not shown), and the respective devices can be operated or quenched by giving control signals to the control devices.

[Action flow]

Fig. 3 is a flow chart showing an example of a mode embodying the present invention. In FIG. 3, in order to inspect the semiconductor wafer 10 in its entirety, photography is performed by each camera. A series of processes are shown in each step. First, the semiconductor wafer 10 is placed on the stage portion 25 of the automatic visual inspection device 1 (s101), and the inspection conditions and the like registered in advance are read (s102). Next, the reading position of the reference mark 10m formed on the semiconductor wafer 10 is moved (s103), and alignment is performed (s104).

Next, the table portion 25 is moved toward the measurement start position of the first row (s107), the scanning platform portion 2 is moved at a predetermined speed, and the movement of the table portion 25 is started (s108). While moving the table portion 25, it is determined whether or not the position to be captured by the camera 1 is based on the current position information of the table portion obtained by the X-axis position detector and the Y-axis position detector of the scanning platform portion (s110). At the photographing position of the camera 1, the flash is illuminated and photographed by the camera 1 (s112), and the movement of the table portion 25 is continued. Further, it is judged whether or not the current position information of the table portion is a position to be photographed by the camera 2 (s114), and if it is the photographing position of the camera 2, the flash is illuminated and photographed by the camera 2 (s115), and the table portion 25 is continued. mobile. On the other hand, if the current position information of the table portion is not the position photographed by any of the cameras, the movement of the table portion 25 is continued.

Then, it is judged whether or not the photographing of the first column is completed based on the current position information of the table portion (s116), and if it is determined that the photographing of the first row is completed, the movement of the table portion is stopped (s117). On the other hand, if it is determined that the photographing of the first column is not completed, the above steps s110 to s116 are repeated.

Next, it is judged whether or not all the photographs have been completed by the above-described photographing (s118), and if it is determined that all the photographing is completed, the inspection unit is taken out by the table portion 25. On the other hand, if it is determined that all of the above steps s118 are not completed In the photographing, the table portion 25 is moved toward the measurement start position of the next row, and the series of photographing steps (s107 to 118) are repeated.

[Timing chart]

4 is a timing chart showing an example of an embodiment of the present invention, and is a view showing the operation of each unit of the automatic visual inspection device 1 described with reference to FIGS. 1 to 3 in time series. In the figure, the horizontal axis represents the time t, and the dotted line is used as the auxiliary line so that the state before and after the operation of each part at each time is clear. The same dotted line above means the same moment.

According to the current position information of the aforementioned table, the photographing instruction is issued for each interval T2. First, the camera used for photographing is switched to the side of the camera 51a (i.e., the camera 1), and the photographing instruction is issued, and the photographing is performed by the camera 1. The flash light is emitted during the shooting of the camera 1, and after the shooting of the camera 1 is completed, the image data is transferred.

In the data transfer of the camera 1, the camera used for photography is switched to the side of the camera 51b (i.e., the camera 2). Then, as soon as the photographing instruction is issued, photographing is performed by the camera 2. The flash light is emitted during the shooting of the camera 2, and after the photographing of the camera 2 is completed, the image data is transferred. In the data transfer of the camera 2, the camera used for photography is switched to the camera 1 side. By repeating the series of operations, continuous shooting can be performed at every interval T2, and continuous shooting can be performed in half the time as compared with the conventional photographing interval T1. Further, if the number of cameras is increased, the interval of continuous shooting can be shortened. At this time, the cameras 51a and 51b use the same camera as in the related art, and the processing capability of the camera can be shortened without limitation.

Further, even in the case where the objective lenses 55a and 55b having different imaging magnifications are provided for the corresponding varieties, the number of the respective objective lenses is not required to be increased in accordance with the number of the cameras. Therefore, the cost increase factor caused by the increase of the objective lens disappears. Further, compared with the configuration in which the plurality of cameras and the plurality of objective lenses constitute the inspection device, the distortion or aberration of the circuit patterns which are caused by the individual differences of the objective lenses disappears, and it is easy to make Check the quality is consistent. Moreover, it is not necessary to separately perform image correction for matching the inspection quality, and various cost increase factors can be eliminated.

[Another form 1]

In the above description, the observation light is branched by the light branching means 45, and the inspection object is imaged by using a plurality of cameras. However, by arranging the light reflecting means 47, the position or angle of the light reflecting means 47 is changed, and the angle at which the observation light is guided is switched so as to replace the form of the light branching means 45. Fig. 5 is a perspective view showing another example of the embodiment of the present invention, showing an automatic visual inspection device 1a including a lens barrel portion 4a of another embodiment, in place of the lens barrel portion 4 of the automatic visual inspection device 1 described with reference to Fig. 1 . . Hereinafter, the difference between the barrel portion 4a and the barrel portion 4 will be described, and the other common points will not be described.

The lens tube portion 4 is provided with a light reflecting means 47 in the middle of observing the path in which the light is guided, and the direction (i.e., the angle) of the observation light can be changed and reflected. The light reflecting means 47 can be arranged such that its position or angle is changed, and can be switched to a position indicated by a symbol 47 and arranged at a to-be-avoided position 47a indicated by a broken line. For example, as shown in FIG. 5, if the light reflecting means 47 intersects the optical axis of the observation light When the fork is arranged to be inclined by 45°, the observation light guided in the Z direction is changed by 90°, and is guided in the X direction, and the observation light is captured by the camera 51b. On the other hand, when the position where the light reflecting means and the optical axis of the observation light do not intersect with each other, the observation light guided in the Z direction is guided in the Z direction as it is, and the observation light is guided by the camera 51a. Shooting.

The light reflecting means 47 can be exemplified by an optical element such as a mirror or a prism, and it is only necessary to change the direction of the incident light and reflect it. The light reflecting means 47 is attached to the hinge through the barrel portion 4a so that one end thereof becomes a center of rotation and is rotatably coupled to the movable member of the actuator portion 60 attached to the barrel portion 4a. Then, the ON/OFF operation of the actuator unit 60 is switched to the position indicated by the symbol 47 and the position indicated by the symbol 47a.

Alternatively, the light reflecting means 47 may be attached to the movable member of the actuator portion 60 in a state where the mounting angle is fixed, and may be mounted by switching the position in the X direction by the ON/OFF operation of the actuator portion 60. The actuator unit 60 is connected to the machine control unit 95, and can be configured to perform an ON/OFF operation based on a command signal from the machine control unit 95.

[Another form 2]

The actuator unit 60 is not limited to the direct-acting type, and may be of a rotary type. The direction of the light-guiding observation light 40v may be changed by changing the position, angle or direction of the light reflecting means 47. Further, it is also possible to arrange the number of cameras as appropriate.

Fig. 6A is a perspective view showing still another example of the embodiment of the present invention, showing the use of the rotary actuator portion 60a and the two cameras 51a, The shape of 51b. Fig. 6B is a plan view showing still another example of the embodiment of the present invention, which is a cross-sectional view taken along line A-A of the plan view 6A.

The observation light passes through the opening 40h of the barrel portion 4b, and is guided to the light reflecting means 48. The light reflecting means 48 is coupled to the rotary actuator portion 60a attached to the barrel portion 4b so as to rotate in the direction of the arrow 60v. The current state is that the observation light 40v guided in the Z direction is changed in the direction indicated by the arrow 48v and guided on the X-direction arrow side, and is reflected by the mirror 43a to be guided in the Z direction. The image taken by the camera 51a. Further, an angle detector 67 (a so-called rotary encoder) (not shown) is attached to the rotary actuator unit 60a, and angle information of the rotary actuator unit 60a can be obtained. The light reflecting means 48 is further rotated in the form shown in Figs. 6A and 6B. When the reflected observation light 48v is directed in the direction of the mirror 43b, the observation light 40v is guided to the side opposite to the X direction arrow. It is reflected by the mirror 43b and guided in the Z direction, and can be observed by the camera 51b. Further, the light reflecting means 48 is further rotated, and if the reflected light 48v which is reflected again is directed in the direction of the mirror 43a, it can be observed by the camera 51a, and the present invention can be repeatedly observed by repeating the above-described series of operations.

Fig. 7 is a timing chart showing still another example of the embodiment of the present invention, and is a view showing the operation of each unit of the automatic visual inspection device described with reference to Figs. 6A and 6B in time series. The horizontal axis in the figure indicates the time t, and a dotted line is used as an auxiliary line in order to make the state before and after the operation of each unit at each time clear. The same dotted line above means the same moment.

According to the current position information of the aforementioned section, the photography indicates each interval T2. Was issued. First, the camera used for photographing is switched to the side of the camera 51a (i.e., the camera 1), and the photographing instruction is issued, and the photographing is performed by the camera 1. The flash light is emitted during the shooting of the camera 1, and the photographing data is transferred after the photographing of the camera 1 is completed.

In the data transfer of the camera 1, the camera used for photography is switched to the side of the camera 51b (i.e., the camera 2). Then, as soon as the photographing instruction is issued, photographing is performed by the camera 2. The flash light is emitted during the shooting of the camera 2, and after the photographing of the camera 2 is completed, the image data is transferred. In the data transfer of the camera 2, it is switched to the side of the camera 1 which is then used for photography. By repeating the series of operations, continuous photographing can be performed every interval T2, and continuous photographing can be performed in 1/2 time as compared with the conventional photographing interval T1. Further, if the number of cameras is increased, the interval of continuous shooting can be shortened.

Further, the encoder portion 65 is attached to the movable member of the actuator portions 60, 60a or the light reflecting means 47 attached to the front end thereof so that the current position of the actuator portion 60, 60a or the light reflecting means 47 can be detected, The angle or direction is now better.

The encoder portion 65 can exemplify a linear scale in which a plurality of optical or electromagnetic pores (so-called slits) are engraved in a rod-shaped, ribbon-shaped member extending in one direction. ), or a circular encoder or a cylindrical member with the same slit rotary encoder or the like.

In the form of the light reflection means 48 as described above, it is possible to prevent a decrease in the amount of light of the observation light caused by the use of the light branching means 45 and the increase in the number of cameras. Therefore, there is no need to increase the sensitivity of the camera, or Using a flash with a higher luminous energy, it is possible to shorten the inspection time by using a camera with the same sensitivity as the conventional one and a flash of the same luminous energy.

[Another form 3]

Fig. 8 is a timing chart showing still another example of the embodiment of the present invention, and is a view showing the operation of each unit of the automatic visual inspection device in time series, similarly to the timing chart described with reference to Fig. 7 . In this embodiment, unlike the automatic visual inspection device described with reference to Fig. 7, the light reflecting means 48 for changing the direction of the observation light in the barrel portion main body 40 does not become completely stopped at the time of light emission of the flash lamp, and the position is a little Change a little. In other words, the light reflecting means 48 is continuously moved by the actuator portion 60a, and is photographed through the respective observation cameras without being completely stopped. When the position and angle of the specific mirror are illustrated, the trajectory shown by the broken line A in FIG. 8 is a state in which the light reflecting means 48 is rotated at a constant number of revolutions. That is, it will not be stationary toward the cameras 1, 2, but will continue to move. At this time, since the illumination light uses a flash having a very short lighting time, it can be handled as blur without observing the image. According to this, in order to strictly switch the direction of the observation light, it is not necessary to completely stop the actuator portion 60a, and the influence of the inertia applied to stop or re-shift is reduced, and the burden on the actuator portion 60a is also reduced. Therefore, continuous shooting can be performed at a higher speed.

In this case, the extent to which the moving speed of the actuator portion 60a when the flash is illuminated is allowed to be the moving distance or angle of the actuator portion 60a when the flash is illuminated, that is, by being practical. It is determined by observing the degree to which the image is processed without blurring. That is to say, the flash light has a very short lighting time, or the number of cameras that are switched is small and the interval between the photos can be lengthened. In the shape, the actuator portion 60a may be driven at the same moving speed as when the flash is illuminated or when the flash is not illuminated.

On the other hand, there is a need for a large number of cameras to be switched to shorten the interval of photographing, or, if it is related to the flashing time of the flash, to be actuated at the same moving speed as when the flash is illuminated or when the flash is not illuminated. When the device 60a is driven to cause blurring of the observed image, it may be performed by slowing down the moving speed of the actuator portion 60a at the time of flash light emission as compared with the case of flashing non-lighting. When the position and angle of the specific mirror are illustrated, the trajectory indicated by the solid line B in FIG. 8 indicates a state in which the light reflecting means 48 is rotated while changing the number of revolutions. In other words, the light reflecting means 48 is directed toward the cameras 1 and 2 while passing through the cameras 1, 2, but is not completely still before and after the light reflecting means 48, and decelerates and continues compared with when the flash is not illuminated (that is, when not observed). Rotate. Then, after the acceleration is performed outside the deceleration interval before and after the shooting, the rotation is performed at a constant speed, and the series of operations before the deceleration before the shooting is repeated.

(Embodiment 1)

Hereinafter, an embodiment in still another example of the embodiment of the present invention described with reference to Figs. 1 to 7 will be described.

The cameras 51a and 51b of the photographing unit 5 are electronic shutter type cameras using a black and white CMOS having a grid-like pixel of 5 μm in pixel pitch as a maximum frame rate of 140 fps of the photographing element. . In the cameras 51a and 51b, about 1600 pixels are arranged in the moving direction of the inspection object 10, and an area sensor of about 1600 pixels is also arranged in the direction orthogonal to the moving direction. (area sensor) is used. Further, the magnification of the objective lens is set so as to obtain an observation area having a length of 4.0 mm in the moving direction of the inspection object 10. Then, the inspection object 10 is moved by 3.0 mm each time, and the illumination is illuminated, and the cameras 51a and 51b perform imaging in an interactive manner. At this time, the scanning platform portion for moving the inspection object 10 is set to 720 mm/sec. Then, the illumination unit 3 is repeatedly illuminated at 240 Hz. In this case, if it is a conventional technique, it is not possible to perform continuous shooting with image transfer at a frame rate of 140 fps. However, by applying the present invention, it is possible to perform photography and video transfer at substantially 120 fps.

Further, the illumination unit 3 is preferably in the form of using a flash lamp using a halogen or a xenon lamp. In the case of a flash lamp, it is possible to relatively easily illuminate a flash having a high luminescence energy (for example, a half-value of energy necessary for photography is 3 μsec wide) in a very small amount of time. Therefore, even in the case of using an inexpensive camera which is not suitable for high-sensitivity photography with a high shutter speed, the energy of the irradiated light can be sufficiently obtained. Therefore, the inspection object that moves at a high speed can be continuously photographed, and the automatic visual inspection can be performed by applying the present invention.

Further, since the observation light 2 is branched by a half mirror and observed by two cameras, the amount of light of the flash lamp is doubled as usual. According to this, the amount of light observed by the respective cameras becomes the same as usual.

When the image blur at this time is focused on, when the flash light is emitted for 3 μsec, the distance at which the inspection object 10 moves is 2.16 μm, which corresponds to blurring of photography. The image blur is about 1/1850 in length of the entire viewing field: 4.0 mm, and is converted into a pixel of the imaging element. Approximately 0.86 pixels. The amount of image blurring also depends on how closely the object is observed. For example, if the minimum line width to be observed is 22 μm (that is, 10 pixels) or more, it can be regarded as a degree that is not considered to be a problem. It is not a problem in applying the present invention. On the other hand, even if the minimum line width to be observed is less than 22 μm, the present invention can be applied by adapting an image processing or an inspection algorithm.

In the above description, an example has been described in which the flash is in a light-emitting state within a predetermined shooting time. However, the present invention is not limited to such a form, and the form in which the illumination light is irradiated for only a predetermined period of time and the photographing is instantaneously performed may be performed by the following embodiment.

Fig. 9 is a timing chart showing a modification of the embodiment of the present invention, and is a modification of the form shown in Fig. 7; That is, in this modification, after the photographing instruction is turned on, the illumination is turned ON only for a predetermined period of time, and the photographing is instantaneously performed during this period. If a specific example is displayed, set the electronic shutter of the camera to 1/100,000 sec (that is, the shooting time is 10 μsec) to 1/500,000 sec (that is, the shooting time is 2 μsec), and the shutter time is set after the shooting instruction is turned ON. The illumination required for the photography is illuminated for 1/100 second (ie, 10 msec) to 1/1000 second (ie, 1 msec), during which time the camera is photographed. Thus, the present invention can be applied to perform an automatic visual inspection.

When the image blurring at this time is focused, when the flash light is emitted for 2 μsec, the distance at which the inspection object 10 moves is 1.44 μm, which corresponds to blurring of photography. The image blurs the length of the entire field of view Degree: 4.0 mm is about 1/2780, and when converted into pixels of the imaging element, it is about 0.57 pixel parts. Further, when the flash light is emitted for 10 μsec, the distance at which the inspection object 10 moves is 7.2 μm, which corresponds to blurring of photography. The length of the image blur to the entire field of view is 4.0 mm, which is about 1/560. When converted to pixels of the image pickup element, it is about 1.44 pixels. The amount of image blurring also depends on how closely the object is observed. For example, if the minimum line width to be observed is 15 to 72 μm (that is, 10 pixels) or more, it can be regarded as substantially not considered a problem. The extent of this is not a problem in the application of the present invention. On the other hand, even if the minimum line width to be observed is less than 15 to 72 μm, the present invention can be applied by adapting the image processing or the inspection algorithm.

(Embodiment 2)

Hereinafter, an embodiment in still another example of the embodiment of the present invention described with reference to FIGS. 6A, 6B, and 7 will be described.

When the two cameras 51a, 51b are used, the rotary actuator portion 60a is driven to rotate the light reflecting means 48 at 120 revolutions per second (i.e., 7200 rpm). Then stagger the half cycle and repeat the photography. According to this, it is the same as the following: Each of the cameras 51a and 51b is photographed at 120 fps, and the actual photographing side is repeated at 240 fps.

(Embodiment 3)

An embodiment of still another example embodying the embodiment of the present invention described with reference to Fig. 8 will be described below.

When the camera is two cameras and is photographed at 120 fps, the rotary actuator is rotated at 360 rpm (ie, 21600 rpm) at 3 times speed. Turning, while rotating at 30 revolutions per second (ie, 1800 rpm) in a decelerating state, it is rotated only 10 degrees before and after the photographing angle, and each of the front and rear 10 degrees is regarded as an acceleration/deceleration region. According to this, the mirror rotation speed in photography is reduced to 1/4, and the amount of image blur is also reduced. Further, when the rotation speed at the time of photographing is increased and the mirror rotation speed during shooting is lowered, the amount of image blurring is further reduced.

(Example of increase in the number of cameras)

In the above description, the form in which two cameras are used has been exemplified, but the present invention is also applicable to a form in which two or more cameras are used. For example, in addition to the form shown in FIGS. 6A and 6B, a mirror for photography and a camera are disposed on the side of the Y-direction arrow on which the light reflecting means 48 is rotated by 90 degrees and on the opposite side. As a result, a total of four cameras can be used with the rotation speed (720 rpm) of the light reflecting means 48 and the shooting rate (120 fps) as they are, and imaging of substantially 480 fps can be performed. In addition, the flash is illuminated at 480 fps.

Further, when the rotation angle is decelerated before and after the photographing, the present invention can be applied by making the angle defined for every 10 degrees to be 5 degrees.

On the other hand, if it is a half mirror branch, the branching light can be branched to four cameras by further branching the branched light. Then, if the flash lamp is illuminated with a normal amount of light of four times and the flash light is emitted at 480 fps, the present invention can be applied.

1, 1a‧‧‧ automatic visual inspection device

2‧‧‧Scanning Platform Department

3‧‧‧Lighting Department

4, 4a, 4b‧‧‧ lens tube

5‧‧‧Photography Department

9‧‧‧Control Department

10‧‧‧Inspection object (wafer)

10m‧‧‧ benchmark mark

10p‧‧‧ circuit pattern

10v‧‧‧ arrow

11‧‧‧ device framework

21‧‧‧X-axis platform

22‧‧‧Y-axis platform

23‧‧‧Rotating platform

25‧‧‧Department of Taiwan

31‧‧‧Coaxial epi-illumination (positive reflection)

31s, 33s, 35s‧‧‧ illumination lighting device

33‧‧‧Ring illumination (slanted light)

35‧‧‧Spot-illuminated illumination (transmitted light)

40‧‧‧Mirror tube body

40h‧‧‧ openings

40v‧‧‧ observation light

41‧‧‧Lighting half mirror

42‧‧‧Photographic mirror

43a, 43b‧‧‧ mirror

45‧‧‧Light branching means (half mirror, etc.)

45v1, 45v2‧‧‧ arrows (direction after branching)

47‧‧‧Light reflection means (mirror, etc.)

47a‧‧‧Light reflection means (to be avoided)

48‧‧‧Light reflection means

48v‧‧‧ arrows (direction of reflection)

51a, 51b‧‧‧ camera

55a, 55b‧‧‧ objective lens

57a, 57b‧‧‧Photo field of view

60‧‧‧Activity Department

60a‧‧‧Actuator section (rotary)

60v‧‧‧arrow (rotation direction)

65‧‧‧Encoder Department

67‧‧‧ Angle detector

90‧‧‧Control computer

91‧‧‧Information input means

92‧‧‧Information output means

93‧‧‧Warning means

94‧‧‧Information Recording Means

95‧‧‧ machine control unit

96‧‧‧Image Processing Unit

T1, T2, Td‧‧‧ interval

Fig. 1 is a perspective view showing an example of a mode embodying the present invention.

Fig. 2 is a system configuration diagram showing an example of a mode embodying the present invention.

Fig. 3 is a flow chart showing an example of a mode embodying the present invention.

Fig. 4 is a timing chart showing an example of a mode embodying the present invention.

Fig. 5 is a perspective view showing another example of the embodiment embodying the present invention.

Fig. 6A is a perspective view showing still another example of the embodiment of the present invention.

Fig. 6B is a cross-sectional view showing still another example of the embodiment of the present invention.

Fig. 7 is a timing chart showing still another example of the embodiment of the present invention.

Fig. 8 is a timing chart showing still another example of the embodiment of the present invention.

Fig. 9 is a timing chart showing a modification of the embodiment of the present invention.

Figure 10 is a timing diagram in the prior art.

1‧‧‧Automatic visual inspection device

2‧‧‧Scanning Platform Department

3‧‧‧Lighting Department

4‧‧‧Mirror tube

5‧‧‧Photography Department

10‧‧‧Inspection object (wafer)

11‧‧‧ device framework

21‧‧‧X-axis platform

22‧‧‧Y-axis platform

23‧‧‧Rotating platform

25‧‧‧Department of Taiwan

31‧‧‧Coaxial epi-illumination (positive reflection)

33‧‧‧Ring illumination (slanted light)

35‧‧‧Spot-illuminated illumination (transmitted light)

40‧‧‧Mirror tube body

40v‧‧‧ observation light

41‧‧‧Lighting half mirror

42‧‧‧Photographic mirror

45‧‧‧Light branching means (half mirror, etc.)

45v1, 45v2‧‧‧ arrows (direction after branching)

51a, 51b‧‧‧ camera

55a, 55b‧‧‧ objective lens

57a, 57b‧‧‧Photo field of view

Claims (7)

An automatic visual inspection device for inspecting a defect of a pattern formed on an inspection object, comprising: a table portion that carries the inspection object; and a scanning platform that scans the table portion in a predetermined direction a illuminating unit that illuminates the illuminating light toward the object to be inspected; and a lens barrel that is guided by the illuminating unit and that is reflected by the object to be inspected or that passes through the object to be inspected as light. a photographing unit that is attached to the barrel portion and that captures the observation light, and that causes the illumination unit to emit light while moving the scanning platform unit, and performs a control unit for photographing the observation light; and performs inspection based on pre-registered inspection conditions. The inspection unit for determining the quality of the image of the inspection target object includes a position measuring means for measuring the current position of the table portion, and the lens barrel portion includes a portion of the observation light that is transmitted through the lens barrel portion. And changing the angle to partially reflect the light branching means, and mounting the plurality of the photographing portions in the barrel portion so as to be able to photograph each of the branches by the light An optical branching section, the control section comprises: a plurality of each of the photography section of the photography in the photographic image data after the transfer, can be sequentially switched to the photographing unit photographing images and transmit the information to the end of the photographing function. An automatic visual inspection device for detecting an object to be inspected The inspection object inspection device of the defective pattern includes a table portion that carries the inspection object, a scanning platform portion that scans the table portion in a predetermined direction, and an illumination portion that illuminates the inspection object with illumination light. a lens barrel portion that is guided by the illumination unit and that reflects light by the inspection object or light that has passed through the inspection object as light, and is attached to the barrel portion to capture the observation light. a photographing unit that controls the photographing unit to emit light while moving the scanning unit, and performs a photographing control unit for photographing the observation light; and performs image quality of the photographed object to be inspected based on pre-registered inspection conditions. The inspection unit includes a position measuring means for measuring a current position of the table portion, and the lens barrel portion includes a light reflecting means for changing an angle or a direction of the observation light and reflecting the same a plurality of the photographing portions are mounted on the barrel portion so as to be able to respectively capture the light reflected by the light reflecting means, and the control portion includes: each of the photographing and the photographing being linked and changing Reflection direction of the reflection means, and a portion of the plurality of photography among the photographic image data after the transfer, can be sequentially switched to the photographing unit photographing images and transmit the information to the end of the photographing function. The automatic visual inspection device according to claim 2, wherein the lens barrel portion is further provided with a position or an angle for changing the light reflecting means. The actuator unit drives the actuator unit in conjunction with the photographing to perform the photographing. An automatic visual inspection device according to claim 3, wherein the position or the angle of the light reflecting means is in a moving state even if the actuator portion is in the photographing. The automatic visual inspection device according to claim 4, wherein the moving speed of the actuator portion in the photographing is slower than the moving speed at the time of non-photographing. The automatic visual inspection device according to any one of claims 3 to 5, wherein a position detector for detecting a current position or an angle detector for detecting a current angle is mounted on the actuator portion or the light reflecting means The photographing is performed based on the information of the position detector or the angle detector. The automatic visual inspection device according to any one of claims 1 to 5, wherein the illumination portion that illuminates the illumination light is a flash unit that illuminates the flash, and the photographing is performed by light emission from the flash lamp.