JP3935911B2 - Board inspection equipment - Google Patents

Description

  The present invention relates to a substrate inspection apparatus used for defect inspection of, for example, a glass substrate of a liquid crystal display (LCD).

  Conventionally, for inspection of defects in glass substrates used in LCDs, illumination is applied to the surface of the glass substrate, and the defect is detected using a macro observation that observes defect portions such as scratches on the substrate surface from optical changes in the reflected light. Some of the micro-observations for magnifying and observing the defective portion are made possible.

  Therefore, conventionally, as disclosed in Patent Document 1, a micro observation system and a micro observation system are provided corresponding to an XY stage that is horizontally movable in the X and Y directions, and an inspection target is provided on the XY stage. Inspected by moving the XY stage in a two-dimensional direction in the X and Y directions from the state where the substrate is placed and positioning the inspection site of the inspection substrate in the observation area of the micro observation system or micro observation system There is one that enables macro observation or micro observation on a defect portion of a substrate surface.

Further, as disclosed in Patent Document 2, the stage is horizontally moved in one direction of the XY direction intersecting on a plane orthogonal to the optical axis of the objective lens, and the objective lens is moved in the other direction. Some have made it possible to observe the entire range of the sample on the stage.
JP-A-5-322783 Japanese Patent Laid-Open No. 5-127088

  By the way, recently, the size of the glass substrate tends to increase with the increase in the size of the LCD. However, Patent Document 1 discloses that the X-Y stage is used as the X-Y stage in the defect inspection of such a large size glass substrate. Since it moves horizontally in the two-dimensional direction of the Y direction, a moving range that is four times the substrate area is required, and thus the size of the substrate and the size of the apparatus cannot be avoided. In addition, since the spot illumination for identifying the defective portion on the glass substrate must be positioned near the center of the XY stage to cover the entire surface of the substrate, the spot illumination is far away from the observer. It is difficult to visually position minute scratches.

  Further, in Patent Document 2, since the stage can be moved only in one direction in the X and Y directions, the size can be reduced as compared with the above-described conventional one. However, since the stage is arranged horizontally, the substrate area is doubled. A moving range is required, and it is impossible to further reduce the size. The objective lens that can be moved in the other directions in the XY directions is connected to an eyepiece lens attached to the observation barrel on the base via a relay lens, and the objective lens is fixed in a state where the position of the eyepiece lens is fixed. Therefore, the defect position on the sample observed by the objective lens may be far from the observation position by the eyepiece.

  This is because, for example, when the spot illumination is matched with the defect portion while confirming the defect portion on the sample by visual observation, or when micro observation with an eyepiece lens is performed, the observer is far from the sample. Since it moves to the position of the defective part far away and confirms the defect state by visual observation, it returns to the eyepiece lens position again and confirms the observation image, so troublesome movement is necessary, and accurate observation of the defective part In addition to causing problems, there was a problem of enormous effort on the observer. In addition, this has become a bigger problem as the distance that the observer moves is further increased as the glass substrate, which is a recent sample, is enlarged.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a substrate inspection apparatus capable of accurately observing a defective portion and realizing reduction in observation work.

According the invention a first aspect, a substrate holding device which is set to a predetermined inclination angle, and the substrate holding unit light source substrate to be inspected Ru macro irradiation Aquiraz retained on the macro illumination emitted from the light source A reflection mirror that deflects light so as to have a predetermined irradiation angle with respect to the surface of the substrate to be inspected;
The reflection mirror is rotatably supported, mirror angle adjusting means for adjusting the rotation angle of the reflection mirror, a drive unit for rotating the reflection mirror, and a rotation of the reflection mirror set by an observer. A control unit that stores moving angle data in a storage unit, reads the rotation angle data from the storage unit, controls the drive unit, and automatically sets the rotation angle of the reflection mirror. It is a feature.

  According to the present invention, the observer can alternately perform microscopic observation by looking into the eyepiece lens and visual observation with the eyes away from the eyepiece lens while staying in the same place, and visually inspecting the defect portion. The state of the defective portion can be accurately grasped by performing the microscope observation while comparing with the state in the above, and the observation work can be reduced by eliminating the unnecessary movement of the observer.

  In addition, the observer can set the observation position to an arbitrary position, for example, by setting the position at the time of microscopic observation to a place where visual observation of the defective portion is easy. Further, the irradiation condition of the macro illumination on the surface of the substrate to be inspected can be set to a state that best suits the observer, and defect detection with high accuracy can be performed.

First, reference examples necessary for describing the embodiment of the present invention will be described.
FIG. 1 shows a schematic configuration of a substrate inspection apparatus as a reference example . In the figure, reference numeral 1 denotes a gantry, and the gantry 1 supports a base 2 in an inclined manner. In this case, the inclined surface of the base 2 is inclined between 45 ° and a state almost parallel to the direction of gravity. In the illustrated example, it is inclined at 60 °.

  A holder 3 is provided on the inclined surface of the base 2 as the inspected substrate holding means. The holder 3 is used to place and hold a large inspected substrate 4 such as a glass substrate used in an LCD. Here, the lower end of the inspected substrate 4 is supported by positioning pins 5, and the base 2. It can be linearly moved in one direction of the XY direction intersecting on the inclined surface, here the Y direction. The base 2 is provided with a Y scale 6 for detecting the position coordinates of the holder 3 in the Y direction.

  An X guide 7 is provided on the base 2 across the holder 3 in a direction orthogonal to the moving direction of the holder 3. The X guide 7 supports the micro observation unit 9 having the spot illumination 8 so as to be movable along the X guide 7 in the other direction of the XY direction described above, in this case, the X direction. Here, the spot illumination 8 projects visible light collected by a laser or optically onto the surface of the inspected substrate 4 on the holder 3. The reflected light on the surface of the substrate 4 to be inspected by this light projection is brighter than the reflected light of the macro illumination unit 11 to be described later, and can be visually observed even during macro observation. The micro observation unit 9 is provided with a microscope function having an objective lens 91 and an eyepiece lens 92, and an observer can observe an observation image obtained from the objective lens 91 by the eyepiece lens 92. In this case, the objective lens 91 and the eyepiece 92 of the micro observation unit 9 are arranged close to each other. Further, the X stage 7 is provided with an X scale 10 for detecting the position coordinates of the micro observation unit 9 in the X direction.

  On the other hand, a macro illumination unit 11 is provided above the gantry 1. This macro illumination unit 11 has a large-diameter lens, and uniformly illuminates the surface of the inspected substrate 4 on the holder 3. That is, the surface light source by such a macro illumination unit 11 uniformly illuminates the surface of the substrate 4 to be inspected on the holder 3, and a change in reflected light on the surface of the substrate 4 to be inspected by the observer's visual observation is regarded as a defective portion. Detected. Specifically, the defect portion is recognized by observing an interference pattern due to unevenness in the film thickness of the substrate, pinholes on the transparent film, dust under the film, etc. by the observer's eyes.

  And the control part 12 is connected to the board | substrate inspection apparatus main body 100 comprised in this way. The control unit 12 manages position coordinates from the Y scale 6 and the X scale 10, controls the movement of the micro observation unit 9, the spot illumination 8, and the holder 3. Further, the irradiation range of the spot illumination 8 and the micro observation unit The relative distance between the centers of each of the nine observation ranges is stored in advance, and a predetermined instruction is given in a state where the irradiation range of the spot illumination 8 is located at a defective portion on the substrate 4 to be inspected. 6 and X scale 10 data, the position coordinates of the defect portion are stored in the storage unit 121, and based on the position coordinates, the relative distance data between the centers of the irradiation range of the spot illumination 8 and the observation range of the micro observation unit 9. Thus, the movement control is performed so that the defect portion designated on the inspected substrate 4 matches the observation range of the objective lens 91 of the micro observation unit 9.

Next, the operation of the thus constructed substrate inspection apparatus will be described. First, the observer gives an instruction to the control unit 12 using a joystick or a keyboard (not shown), moves the holder 3 upward to move it away from the X guide 7, and moves the micro observation unit 9 and the spot illumination 8 to the end of the X guide 7. Is moved away from the holder 3. FIG. 1 shows this state.

  Next, the substrate to be inspected 4 is supported by the positioning pins 5 on the holder 3, the substrate to be inspected 4 is placed on the inclined surface of the holder 3, and the substrate to be inspected 4 is securely held by a suction means (not shown). After that, the defect inspection is started.

  In this case, as shown in FIG. 2, the surface of the inspected substrate 4 on the holder 3 is uniformly illuminated by the macro illumination unit 11. Then, from this state, an interference pattern due to unevenness in the film thickness of the substrate 4 to be inspected, pinholes on the transparent film, dust under the film, etc. is observed by an observer to recognize a defective portion.

  In this case, the macro illumination unit 11 illuminates a range wider than the width dimension of the substrate 4 to be inspected, but if the range is narrower than the length dimension of the substrate 4 to be inspected, the holder 3 is moved up and down by the base 2. Thus, the entire surface of the inspected substrate 4 is covered.

  Next, when the observer visually recognizes a defective portion on the inspected substrate 4, the holder 3 is moved up and down along the base 2, and the micro observation unit 9 is moved left and right along the X guide 7. Then, the defective portion on the inspected substrate 4 is positioned in the spot irradiation range of the spot illumination 8. From this state, when the observer performs a key operation and gives a predetermined instruction to the control unit 12, the position coordinates of the defective portion are obtained based on the data of the Y scale 6 and the X scale 10 and stored in the storage unit 121. Is done. Subsequently, the control unit 12 uses the position coordinate data and the data of the relative distance between the centers of the irradiation range of the spot illumination 8 and the observation range of the micro observation unit 9 stored in advance, and the holder 3 and the micro The movement of the observation unit 9 is controlled, and the defective part on the inspected substrate 4 visually confirmed is moved to the observation range of the objective lens 91 of the micro observation unit 9. When micro observation is performed immediately after macro observation with respect to each defect portion, the defect portion is moved by moving the holder 3 by the distance between the spot illumination 8 and the lens 91 in a state where the defect position is designated by the spot illumination 8. Can be matched with the observation range of the objective lens 91. Accordingly, the observer can observe the defect portion on the inspected substrate 4 obtained through the objective lens 91 with a microscope by looking into the eyepiece lens 92 of the micro observation unit 9.

  Further, when macro observation is instructed again by a key operation (not shown), the defective portion on the inspected substrate 4 is returned to the irradiation range of the spot illumination 8 and can be reconfirmed by the interference pattern. And when continually observing another defective part, the operation mentioned above will be repeated.

  Thereafter, when the defect inspection is completed, the observer again gives a predetermined instruction to the control unit 12 with a joystick or a keyboard (not shown), moves the holder 3 above the X guide 7, and further, the micro observation unit 9, the spot The illumination 8 is moved to the end of the X guide 7 and returned to the initial position so that the inspected substrate 4 can be replaced from the holder 3.

  Then, in a state where the suction of the substrate 4 to be inspected on the holder 3 is released, the substrate 4 is caused to be vertical or close to an angle and removed from the holder 3. When removing from the holder 3, the lower end of the substrate 4 to be inspected is supported by the positioning pins 5 and there is no danger of dropping, so it can be changed to both ends of the substrate 4.

  Therefore, in this way, the holder 3 on which the substrate to be inspected 4 is placed is moved up and down along the base 2 in order to position the defective portion on the substrate to be inspected 4 in the spot irradiation range of the spot illumination 8. Since the micro observation unit 9 moves left and right along the X guide 7, the holder 3 can be moved about twice the area of the substrate 4 to be inspected, and the installation area can be reduced by tilting the holder 3. And increase in size of the apparatus can be minimized.

  Further, the defect portion on the inspection substrate 4 is further moved to the observation range of the objective lens 91 of the micro observation unit 9 from the state where the defect portion on the inspection substrate 4 is positioned in the irradiation range of the spot illumination 8. However, in this state, the eyepiece 92 of the micro observation unit 9 is positioned near the defect on the substrate 4 to be inspected, so that the observer looks into the eyepiece 92 while staying in the same place. Since the observation by the microscope and the visual observation with the eyes away from the eyepiece 92 can be performed alternately, the state of the defective portion can be accurately grasped by performing the microscopic observation while comparing with the visual state of the defective portion. Furthermore, it is possible to reduce the labor of observation work by eliminating unnecessary movement of the observer. In addition, by tilting the holder 3, in particular, tilting in a state almost parallel to the direction of gravity makes it easier for the substrate to be inspected 4 to be close to the observer and to see the defective portion, and positioning of the spot illumination. In addition, since the substrate to be inspected 4 held by the holder 3 can be visually observed and observed with a microscope at the height of the eyes of the observer, the workability can be further improved.

Figure 3 schematically shows the structure of the implementation of the present invention, the same parts as in FIG. 1 are denoted by the same reference numerals. In this case, the macro illumination unit 41 for the holder 3 surface on the base 2 has a light source 411 and a reflection mirror 42, and the rotation angle of the reflection mirror 42 can be varied by the drive unit 40, so that the holder 3 surface The illumination angle of the macro illumination with respect to can be changed. A control unit 401 is connected to the drive unit 40. The control unit 401 includes a storage unit 402. The storage unit 402 stores the rotation data of the reflection mirror 42 set for each observer, and when the same observer uses the second and subsequent times. In this case, only by designating an observer, the previous data is read, and the rotation angle of the reflection mirror 42 can be automatically set with respect to the drive unit 40.

FIG. 4 shows a drive unit for driving the reflection mirror 42 by manual operation. In this case, the reflecting mirror 42 rotatably supports the lower edge of the side surface opposite to the reflecting surface by the hinge 43. Further, a slide bar 45 protrudes from the upper edge of the side opposite to the reflecting surface of the reflecting mirror 42 by a block 44. The slide bar 45 is supported by a ball bush 46 so as to be slidable in the axial direction. The slide bar 45 is provided with a spring 451 between the ball bush 46 and the block 44. The spring 451 always acts on an elastic force in a direction of pressing the reflection mirror 42.

  The ball bushing 46 has a hole portion through which the slide rod 45 is inserted, and a large number of balls are rotatably supported on the inner surface of the hole portion. The slide rod 45 inserted into the hole portion is inserted into the hole portion by a ball. By supporting it, it slides along the axial direction of the hole. Further, the ball bush 46 is rotatably supported by a bush support portion 47 attached to a fixed portion (not shown) so as to be able to cope with the rotation operation of the reflection mirror 42 according to the slide of the slide bar 45.

  A first belt 48 is connected to the tip of the slide bar 45. The first belt 48 has a tooth portion 481 on one surface, changes the 90 ° direction via a pulley 49 meshed with the tooth portion 481, and has a tooth portion 511 via a joint 50. The second belt 51 is connected.

  Then, the pulley 52 is engaged with the tooth portion 511 of the second belt 51, and the lever 54 is attached to the shaft 53 of the pulley 52, whereby the second belt is rotated via the pulley 52 by the turning operation of the lever 54. By moving 51 and sliding the slide bar 45, the reflecting mirror 42 can be rotated around the hinge 43. In this case, the lever 54 has a ratchet mechanism (not shown), so that the ratchet mechanism can be released and locked by an operation in a direction perpendicular to the operation direction for rotating the reflection mirror 42 so that the operation of the reflection mirror 42 can be regulated. It is also.

  In such a configuration, when the observer manually releases the ratchet mechanism of the lever 54 and then rotates in the direction of the arrow in the drawing, the pulley 52 rotates according to the amount of rotation of the lever 54 at this time. The second belt 51 is linearly moved, the slide bar 45 is slid along the ball bushing 46 via the first belt 48, and the reflection mirror 42 rotates around the hinge 43 according to the slide amount of the slide bar 45. Moved.

  In this case, when the second belt 51 is linearly moved upward in the figure by operating the lever 54, the reflecting mirror 42 is rotated clockwise by the elastic force of the spring 451 according to the sliding amount of the slide bar 45. When the second belt 51 is linearly moved downward in the figure, the reflecting mirror 42 is rotated counterclockwise against the elastic force of the spring 451 in accordance with the sliding amount of the slide bar 45. .

  Thereby, by adjusting the rotation angle of the reflection mirror 42 of the macro illumination unit 41 by the rotation operation of the lever 54 by the observer, the irradiation condition of the macro illumination on the surface of the holder 3 is optimized for each observer. Can be set.

  Further, the data of the rotation angle of the reflection mirror 42 set by the observer is sent to the control unit 401 and stored in the storage unit 402 for each observer. The data stored in the storage unit 402 is read from the storage unit 402 only by designating the observer when the same observer uses the data thereafter, and the reflection mirror is driven by the drive unit 40 based on this data. The rotation angle of 42 is automatically set to the optimum state.

  Therefore, in this way, the observer manually operates the lever 54 to adjust the macro illumination irradiation angle with respect to the surface of the holder 3, so that the irradiation condition of the macro illumination with respect to the surface of the holder 3 is the best for the observer. Since it can be set to a suitable state, it is possible to detect defects with higher accuracy. Moreover, the data of the irradiation angle of the macro illumination set by the observer is stored in the storage unit 402, and when the same observer uses the second and subsequent times, only by designating the observer, based on the previous data, Since the macro illumination angle can be automatically set, usability is further improved.

In the above description, the case where the reflection mirror 42 is manually operated by the observer has been described. However, the rotation angle of the reflection mirror 42 can be automatically set. In this case, as shown in FIG. 5 (a) (b), a reflecting mirror 42 is rotatably supported by the lower edge of the opposite side and the reflective surface hinge 43. Further, the tip of the pressing rod 55 is in contact with the upper edge of the reflecting surface of the reflecting mirror 42. In this case, a roller 551 as shown in FIG. 5B is provided at the tip of the pressing rod 55 so that the reflecting mirror 42 is pressed smoothly.

  The proximal end portion of the pressing rod 55 is fixed to the fixing member 56. The fixing member 56 has a pair of arms 561, and these arms 561 are movably supported by the sliding member 57, and the amount of rotation of the reflection mirror 42 is determined according to the amount of movement of the fixing member 56. ing. A ball screw 59 is connected to the fixing member 56 via a nut portion 58, and a stepping motor 61 is connected to the ball screw 59 via a coupling 60. Reference numeral 62 denotes a spring that always exerts an elastic force for attracting the reflecting mirror 42 to the fixing member 56.

  Thus, when the stepping motor 61 is driven according to the observer's instruction, the ball screw 59 rotates, and the fixing member 56 is moved along the sliding member 57 via the nut portion 58, and according to the movement amount of the fixing member 56. Thus, the reflection mirror 42 is rotated around the hinge 43. In this case, when the fixing member 56 is moved in the direction toward the reflection mirror 42 by the stepping motor 61, the reflection mirror 42 is rotated counterclockwise according to the movement amount of the fixing member 56, and the fixing member 56 is reflected. When moved in a direction away from the mirror 42, the reflecting mirror 42 is rotated counterclockwise.

  Accordingly, even in this case, by operating the rotation amount of the stepping motor 61 according to the instruction of the observer, the irradiation condition of the macro illumination on the surface of the holder 3 can be set to an optimum state for each observer. The same effect can be expected. Further, instead of the stepping motor 61, an encoder that detects the rotation amount of the AC servo motor as the number of pulses may be combined, or a DC servo motor and an encoder may be combined in the same manner.

  In addition, this invention is not limited to the said embodiment, In the implementation stage, it can change variously in the range which does not change the summary.

  Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and is described in the column of the effect of the invention. If the above effect is obtained, a configuration from which this configuration requirement is deleted can be extracted as an invention.

The figure which shows schematic structure of the reference example required in order to demonstrate this invention. The figure for demonstrating operation | movement of the reference example . Shows a schematic configuration of implementation of the embodiment of the present invention. The figure which shows schematic structure of the operation mechanism of the reflective mirror used for embodiment of this invention . The figure which shows schematic structure of the other example of the operation mechanism of the reflective mirror used for embodiment of this invention .

Explanation of symbols

1 ... Stand, 2 ... Base, 3 ... Holder,
4 ... Board to be inspected, 5 ... Positioning pin,
6 ... Y scale, 7 ... X guide, 8 ... spot lighting,
9 ... micro observation unit, 91 ... objective lens, 92 ... eyepiece,
10 ... X scale, 11 ... macro lighting unit, 12 ... control unit,
121 ... Storage unit, 100 ... Substrate inspection apparatus body ,
40 ... Drive unit, 401 ... Control unit, 402 ... Storage unit,
41 ... Macro lighting unit, 42 ... Reflection mirror,
43 ... Hinge, 44 ... Block, 45 ... Slide bar,
451 ... Spring, 46 ... Ball bushing, 47 ... Bush support,
48 ... first belt, 49 ... pulley, 50 ... joint,
51 ... second belt, 52 ... pulley, 53 ... shaft,
54 ... Lever, 55 ... Pressing bar, 56 ... Fixing member,
561 ... arm, 57 ... sliding member, 58 ... nut portion,
59 ... Ball screw, 60 ... Coupling, 61 ... Stepping motor.

Claims (2)

Substrate holding means set at a predetermined inclination angle;
A light source Ru macro irradiation Aquiraz be inspected substrate held on the substrate holding unit,
A reflection mirror for deflecting the macro illumination light emitted from the light source so as to have a predetermined irradiation angle with respect to the surface of the substrate to be inspected;
Mirror angle adjusting means for rotatably supporting the reflection mirror and adjusting the rotation angle of the reflection mirror;
A drive unit for rotationally driving the reflection mirror;
The rotation angle data of the reflection mirror set by the observer is stored in a storage unit, the rotation angle data is read from the storage unit, and the drive unit is controlled to automatically set the rotation angle of the reflection mirror. A control unit to be set;
A board inspection apparatus comprising: Wherein the control unit, the illumination condition of the illumination macro is stored in the storage unit of the rotation angle data of the reflecting mirror to be optimum state, the observer is specified from the storage unit by specifying for each observer automatically board inspection apparatus according to claim 1, wherein the setting by reading the rotation angle data corresponding to the observer by controlling the driving unit rotation angle of the reflecting mirrors.

Images