JP2006194819A - Inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection device capable of moving an inspected body at a high straightness and performing accurate inspection. <P>SOLUTION: This inspection device comprises an air slider 51 that is disposed movably in the X direction between a pair of guide shafts 52 and produces a fine clearance between it and guide shafts 52, a straight line driving mechanism 40 for moving the air slider 51 in the X direction, a mask holder 7 that moves with the air slider 51 and holds a mask in the Y direction, a glass rail 71 that is disposed on the upside of the mask holder 7 and disposed along the X direction, a pair of air pads 72 disposed so as to grip the glass rail 71 from the Z direction perpendicular to the X direction, and a pair of holder gripping tools 73 that are disposed correspondingly to the pair of air pads 72 and arranged so as to grip the upper part of the mask holder 7. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inspection apparatus, and more particularly to an inspection apparatus that moves an object to be inspected in the horizontal direction.

  In a semiconductor inspection apparatus, an LCD inspection apparatus, a photomask inspection apparatus, etc., a substrate is monitored by a CCD camera or the like to check for defects. Further, in order to inspect the entire surface of the substrate, the inspection is performed by accurately moving the CCD camera and the mask. In these inspection apparatuses, there are a method of holding a substrate to be inspected horizontally and a method of holding it vertically. The horizontal holding method has an advantage that a structure having a movable structure of a CCD camera or a substrate can be easily designed and manufactured. In the mask inspection apparatus, the detection is performed by only one CCD camera and compared with the CAD data stored in the database, and inspection is performed by the die to database method for inspecting defects and the like, and by the heads of two CCD cameras separated by a fixed interval. The Die to Die method is used in which defects are inspected by comparing the data.

  However, due to the recent increase in substrate size, the mask size also increases, and if the mask is held horizontally, the mask will bend due to its own weight. Also, particles may be generated during inspection and fall on the mask. Since an error may occur in the inspection due to these, an inspection apparatus using a method of holding the mask vertically is disclosed by the applicant of the present application. (Patent Document 1). The vertical holding method can minimize the deflection of the mask to be inspected. Furthermore, the influence of particles can be reduced. In addition, there is an advantage that the mask can be placed vertically to reduce the size, space and weight.

  In this inspection apparatus, first, the mask is held vertically. Imaging means such as a CCD camera for imaging the pattern provided on the mask is fixed at a certain height. Then, the mask is moved in the horizontal direction at a constant speed in front of the CCD camera. As a result, the mask passes in front of the CCD camera, and an image of one line along the horizontal direction is captured. Then, the height of the CCD camera is changed and the horizontal movement of the mask is repeated. Thereby, the entire surface of the mask can be inspected.

  In the method of holding the inspection mask vertically, it is necessary to drive the mask in the horizontal axis direction in order to capture an inspection image. The straightness (straightness, yawing, pitching, rolling) and rigidity of the movement of the substrate are important factors that determine the inspection accuracy of the inspection apparatus, and a higher level is required. Further, with the recent miniaturization of the wiring width, the pattern shape of the mask has been miniaturized, and a higher level of straightness has been required.

  An air slider is used as such a linear guide device (linear guide) for moving the mask horizontally. Specifically, an air slider to which a mask holder for holding a mask is attached is separated from the guide shaft by a minute gap of about 2 to 6 μm by air pressure (Patent Document 2). Thereby, an air slider is supported by non-contact. Then, the air slider is moved in the horizontal direction by a linear drive mechanism such as a linear motor while the air slider is supported in a non-contact manner. As a result, the mask moves smoothly along the horizontal direction. The air slider is provided so as to surround the outer periphery of the guide shaft having a rectangular cross section. In order to improve straightness, air is ejected to the four surfaces of the upper surface, the lower surface, and the two side surfaces of the guide shaft, and an air gap is provided for each surface. And air is ejected so that the air gap with respect to each surface may be kept constant. Therefore, the air slider is separated from the upper, lower and side surfaces of the guide shaft by a predetermined minute gap. As a result, the air slider moves straight along the guide shaft. However, this linear guide device has a problem in that the structure becomes complicated because it is necessary to surround the entire circumference of the guide shaft.

JP 2004-68940 A JP 2004-60833 A

  In the conventional mask inspection apparatus, when the mask is held vertically and moved horizontally, there are the following problems. In a conventional mask inspection apparatus, an air slider is directly mounted on a stage, and the stage surface is used as a pressure surface for air levitation. When attempting to hold the mask vertically with this type of air slider, the mask may fall forward or backward due to its own weight. That is, as the rotational moment load is applied to the air slider, the mask holder falls back and forth. When such forward tilt or backward tilt occurs, the minute gap generated by the air slider becomes partially zero, and so-called galling occurs. In particular, as the mask size increases, such a problem appears more prominently. Therefore, it may be difficult to move the mask horizontally with good straightness. In this case, the inspection accuracy is deteriorated.

This problem is not limited to a mask, but occurs in an inspection apparatus using a linear guide device that holds a substrate vertically and moves it horizontally.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an inspection apparatus capable of moving a substrate horizontally with good straightness.

  The inspection apparatus according to the first aspect of the present invention includes an air slider that floats by ejecting air (for example, the air slider 51 according to the embodiment of the present invention), and the air slider is floated. The inspection apparatus detects the light from the object to be inspected (for example, the mask 6 according to the embodiment of the present invention) while moving in the horizontal direction, and is fixed along the first direction. An air slider provided between the pair of guide shafts (for example, the guide shaft 52 according to the embodiment of the present invention) and the pair of guide shafts so as to be movable along the first direction. , An air slider that ejects air to the guide shaft and generates a minute gap between the guide shaft and a drive mechanism that moves the air slider in a first direction (for example, according to an embodiment of the present invention) Linear drive 40), a holder that moves together with the air slider and holds the object to be inspected in the vertical direction (for example, mask holder 7 according to an embodiment of the present invention), and light that detects light from the object to be inspected A detector (for example, the CCD camera head 3a according to the embodiment of the present invention) and a rail (for example, in the embodiment of the present invention) provided on the upper side of the holder and provided along the first direction. The glass rail 71), a pair of air pads (for example, the air pad 72 according to an embodiment of the present invention) provided so as to sandwich the rail from a second direction perpendicular to the first direction, A pair of holder holding tools (for example, a holder holding tool 73 according to an embodiment of the present invention) provided to correspond to the pair of air pads and arranged so as to sandwich the upper part of the holder. It is. As a result, the substrate can be moved horizontally with good straightness, and the inspection can be performed accurately.

  The inspection apparatus according to a second aspect of the present invention is the inspection apparatus described above, wherein at least one of the pair of holder holding tools has a leaf spring, and the leaf spring extends the upper portion of the mask holder in the second direction. By pushing, the holder is moved in a state parallel to the vertical direction. Accordingly, the holder can be moved while being held in a state parallel to the vertical direction.

  The inspection apparatus according to a third aspect of the present invention is the inspection apparatus described above, wherein the holder is arranged at a position different from a portion where the air slider receives a load in the second direction. Thereby, it can prevent effectively that a holder falls down.

  An inspection apparatus according to a fourth aspect of the present invention is the above-described inspection apparatus, the holder support provided on the air slider and supporting the holder (for example, the holder support according to an embodiment of the present invention) 54), the end of the holder support in the second direction is formed so as to protrude upward, and the air slider receives the load by disposing the holder in the protruding portion. The holder is arranged at a different position. Thereby, it is possible to effectively prevent the holder from falling down with a simple configuration.

An inspection apparatus according to a fifth aspect of the present invention is the above-described inspection apparatus, wherein two of the air sliders are provided so as to be arranged at least at the end of the holder, and the connection plate connects the two air sliders. (For example, a connection plate according to an embodiment of the present invention), and the holder support is attached to the connection plate. As a result, the holder can be held horizontally with a simple configuration.
An inspection apparatus according to a sixth aspect of the present invention is the inspection apparatus described above, wherein at least a part of the lower surface of the holder support is a curved surface, and the holder is provided so as to be inclined with respect to the air slider. Is. As a result, the holder support can be prevented from galling.

  The inspection apparatus according to a seventh aspect of the present invention is the above-described inspection apparatus, wherein in the pair of air pads, the air pressure of the air pad disposed on the side where the air slider of the holder receives a load is disposed on the opposite side. The air pressure of the air pad is higher. Thereby, it can prevent effectively that a holder falls down.

  An inspection apparatus according to an eighth aspect of the present invention is the above-described inspection apparatus, wherein the position of at least one of the pair of air pads is displaced in the second direction, and the vertical displacement of the object to be inspected is corrected. A position correcting mechanism is provided. As a result, it is possible to correct a vertical position shift that occurs based on a position shift caused by rail undulation or the like.

  ADVANTAGE OF THE INVENTION According to this invention, the board | substrate can be moved horizontally with sufficient straightness, and the test | inspection apparatus which can test | inspect accurately can be provided.

  Hereinafter, embodiments to which the present invention can be applied will be described. The following description explains the embodiment of the present invention, and the present invention is not limited to the following embodiment. For clarity of explanation, the following description is omitted and simplified as appropriate. Further, those skilled in the art will be able to easily change, add, and convert each element of the following embodiments within the scope of the present invention. In addition, what attached | subjected the same code | symbol in each figure has shown the same element, and abbreviate | omits description suitably.

  A mask inspection apparatus using the linear guide apparatus according to the present invention will be described with reference to FIG. FIG. 1 is a perspective view schematically showing a configuration of a mask inspection apparatus. 1 is a prism for a head, 2 is a surface plate, 3 is a head unit, 3a is a CCD camera head, 4 is a balance weight (counter weight), 5 is a wire, 7 is a mask holder, 8 is a vertical drive mechanism, and 9 is a first Reference numeral 10 is a second reference plane, 11 is an air pad, 12 is a head right-angle stage, 16 is a head motor, 18 is a motor stage, and 30 is a horizontal movement mechanism.

  A rectangular parallelepiped head prism 1 is vertically mounted on a surface plate 2 serving as a stage, and a mask holder 7 is set up vertically on the side. The head prism 1 and the surface plate 2 are made of granite (granite) in order to achieve easy processing and flatness. A material other than granite such as metal or ceramic may be used. A mask as an object to be inspected is attached to the mask holder 7. Here, a mask is attached to the side opposite to the head prism 1. The mask holder 7 is transparent or hollow at the portion corresponding to the mask so that the mask can be inspected. Thus, the mask pattern can be imaged by the CCD camera head 3a. During inspection, the mask holder 7 moves in the X direction (horizontal direction). Head right angle stages 12 are provided on two adjacent surfaces of the head prism 1. A CCD camera head 3a is attached to the right angle stage 12 for the head. An air pad 11 is attached to each of the head prisms 1 on the head right-angle stage 12. A moving unit composed of the CCD camera head 3a, the right angle stage 12 for the head, the air pad 11 and the like moves up and down. The head right-angle stage 12 moves along the first reference surface 9 and the second reference surface 10 of the head prism 1. The CCD camera head 3a detects transmitted light, reflected light, or scattered light from the mask attached to the mask holder 7, and images a predetermined area of the mask.

  A wire is attached to the upper portion of the right-angle stage 12 for the head, and a balance weight 4 that is balanced with the moving portion is provided at the tip through the pulley as shown in FIG. The head right-angle stage 12 is moved up and down by a vertical driving mechanism 8 including a motor stage 18 and a rack and pinion. Specifically, the head motor 16 attached to the motor stage 18 is rotated to move the head right-angle stage 12 in the vertical direction. Therefore, it is desirable that the wire 5 is provided at the center of gravity position of the moving portion including the CCD camera head 3a, the right-angle stage 12 for head, the air pad 11, and the like. Thereby, the vertical movement can be performed with high straightness. This vertical movement control is performed by a control processing apparatus provided outside, and the CCD camera head 3a can be moved to a mask inspection position. In addition, clean air is flowing down in the apparatus to suppress the generation of particles.

  While the CCD camera head 3a is held at a predetermined position, the mask holder 7 is moved at a constant speed in the X direction by the horizontal movement mechanism 30 to pass the mask in front of the CCD camera head 3a. The horizontal movement mechanism 30 includes a linear guide device (linear guide) having an air slider and the like, and a linear drive mechanism having a linear motor and the like. The horizontal movement mechanism 30 will be described later. In order to make the mask horizontal, the mounting angle between the mask and the mask holder 7 can be adjusted. Then, images from the CCD camera are detected at regular time intervals. With this image, the mask is inspected for defects and abnormalities. Then, after moving the CCD camera head 3a by a certain distance in the vertical direction, the mask is moved again in the X direction to detect the mask image. By repeating this operation, the entire surface of the mask can be inspected. For example, in the Die To Database method, data stored in a database of a processing device is compared with a detected image to determine the presence or absence of a defect. Of course, the inspection may be performed by the Die to Die method using the heads of two CCD cameras that are spaced apart from each other at a constant interval. The movement step in the vertical direction and the movement speed in the horizontal direction of the mask are adjusted according to the visual field range and performance of the CCD camera. The CCD camera is provided with an autofocus mechanism. Therefore, even when the position of the mask holder 7 in the Z direction is shifted, the inspection can be performed accurately. In addition, since the method similar to the past can be used about the detection method of a defect etc., detailed description is abbreviate | omitted. In FIG. 1, the detailed shape and the like of the linear guide device of the horizontal movement mechanism are not shown.

  Next, the horizontal movement mechanism 30 will be described with reference to FIG. As described above, the horizontal movement mechanism 30 includes the linear guide device 50 and the linear drive mechanism disposed below the mask holder 7. Here, the illustration of the linear drive mechanism is omitted because it will be described later. Further, the horizontal movement mechanism 30 includes a fall prevention mechanism 70 and a position correction mechanism 80 disposed on the upper part of the mask holder 7.

  First, the linear guide device 50 will be described. The linear guide device 50 includes an air slider 51, a guide shaft 52, a connecting plate 53, and a holder support 54. An air slider 51 is disposed on the surface plate 2. The air slider 51 ejects air to the surface plate 2 and slides in a state where it floats from the surface plate 2. On both sides of the air slider 51, L-shaped guide shafts 52 are provided. The guide shaft 52 is provided so as to surround the air slider 51 having a convex cross section. And it arrange | positions so that the center upper part of the air slider 51 may open | release. That is, the guide shaft 52 is disposed so as to sandwich the air slider 51 along the side surface of the air slider 51, that is, along the X direction. A guide shaft 52 having an L-shaped cross section is disposed on the upper side of the air slider 51 so as to protrude inward from the side surface so as to cover a part of the upper surface of the air slider 51. The air slider 51 has an exhaust hole for discharging air introduced from an external air line (not shown). The air slider 51 is made of, for example, a sintered body such as ceramic, and exhaust holes are provided on the upper surface, the lower surface and the side surface. The air slider 51 ejects air from the lower surface, the side surface, and the upper surface. Therefore, a minute gap is generated by the air pressure between the outer side surface of the air slider 51 and the inner side surface of the guide shaft 52 and between the upper surface of the air slider 51 and the lower surface of the protruding portion of the guide shaft 52. Further, a minute gap is generated between the upper surface of the surface plate 2 and the lower surface of the air slider 51. Thereby, since the air slider 51 floats with respect to the surface plate 2, it is hold | maintained in a non-contact state. Thereby, the air slider 51 is supported by non-contact. Therefore, the mask holder 7 can be smoothly moved along the X direction. The air slider 51 moves between the guide shafts 52. That is, the guide shaft 52 becomes the guide shaft of the air slider 51. The guide shaft 52 is fixed to the surface plate 2.

  The length of the guide shaft 52 is determined by the size of the mask and the mask holder 7. That is, the length of the guide shaft 52 is set to be within a movable range in which the entire mask surface of the mask holder 7 can be inspected. For example, the guide shaft 52 has such a length that the stroke of the air slider 51 in the X direction is about 1800 mm. As shown in FIG. 3, the air slider 51 is disposed at each end of the mask holder 7. That is, the two air sliders 51 are provided apart from each other so as to correspond to both ends of the mask holder 7. Each air slider 51 has a length of about 300 mm in the X direction. A connecting plate 53 that connects the two air sliders 51 is provided on the air slider 51. That is, the two air sliders 51 are connected by the connecting plate 53 and move integrally along the X direction.

  A holder support 54 is provided on the connecting plate 53. As shown in FIG. 2, the mask holder 7 is disposed on the upper surface of the end of the holder support 54 in the −Z direction. In order to attach the mask holder 7, the holder support 54 protrudes upward at the −Z side end of the holder support 54. Then, the mask holder 7 is attached at a portion protruding above the holder support 54. Further, the central portion of the holder support 54 in the Z direction protrudes downward. The portion protruding downward is attached to the connecting plate 53. Accordingly, the air slider 51, the connecting plate 53, the holder support 54, and the mask holder 7 are integrally moved along the X direction.

  The configuration of the linear guide device 50 will be described with reference to FIG. FIG. 4 is a cross-sectional view showing a configuration of the linear guide device 50. FIG. 4 is a cross-sectional view in the YZ plane. In FIG. 4, the mask holder 7 is omitted for illustration.

  An air slider 51 is placed directly on the surface plate 2. Therefore, the air slider 51 uses the upper surface of the surface plate 2 as one of the pressure surfaces for air levitation. Guide shafts 52a and 52b are arranged on both sides of the air slider 51 having a convex cross section. The guide shafts 52a and 52b are fixed to the surface plate 2. A minute gap is generated between the air slider 51 and the guide shaft 52 by the air ejected from the air slider 51. A connecting plate 53 having a rectangular cross section is provided at a portion protruding above the air slider 51. As described above, the connecting plate 53 is for connecting the two air sliders 51. The number of air sliders 51 may be other than two. A central portion in the Z direction of the connecting plate 53 is supported by the air slider 51. That is, the portion protruding above the air slider 51 supports the central portion of the connecting plate 53 in the Z direction.

  Further, a holder support 54 is attached to the upper side of the connecting plate 53. A central portion in the Z direction of the holder support 54 protrudes downward. Therefore, the protruding portion of the holder support 54 is attached to the connecting plate 53. In other words, the holder support 54 is attached to the central portion of the connecting plate 53 in the Z direction. Further, the holder support 54 protrudes upward in the −Z direction. As described above, the mask holder 7 is placed on the portion protruding upward. In the present invention, even when the connecting plate 53 receives a force in the direction of the arrow 62, the inclination of the holder support 54 with respect to the connecting plate 53 can be changed in the θ direction. Accordingly, the mask 6 and the mask holder 7 are inclined with respect to the air slider 51, and the position of the mask 6 can be displaced by ΔY.

Note that the holder support 54 may be attached to the connecting plate 53 as shown in FIG. That is, the positioning pin 54 b is provided on the protruding portion 54 a that protrudes downward from the holder support 54. A positioning hole is provided at a position corresponding to the positioning pin 54 b on the upper surface of the connecting plate 53. The holder support 54 can be attached to the connecting plate 53 by fitting the positioning pins 54b with the positioning holes. Thereby, it can attach to an exact position easily. Here, the lower surface of the protruding portion 54a of the holder support 54 is formed in a spherical shape. Thereby, the holder support 54 can be attached to an accurate position with a simple configuration.
In this way, at least a part of the lower surface of the holder support 54 is formed as a downwardly convex curved surface. And the holder support 54 and the connection board 53 are made to contact in this curved surface. Here, the positioning pin 54b is formed smaller than the positioning hole, and the positioning pin 54b is inserted into the positioning hole with a certain gap. With such a configuration, the holder support 54 is disposed so as to be inclined with respect to the connecting plate 53. In other words, the holder support 54 is held tiltably by rolling contact with the air slider 51 and the connecting plate 53. In other words, the curved surface of the holder support 54 and the upper surface of the connecting plate 53 can be tilted by rolling contact, so that the contact surface can be prevented from galling. In this way, the lower surface of the protruding portion 54a is a spherical surface, and this spherical surface is a contact surface. Thereby, the holder support tool 54 is tiltably held. With such a configuration, even when a force is applied in a direction in which the mask holder 7 is inclined, it is possible to prevent galling on the contact surface.

  Thus, the connecting plate 53 is supported by the air slider 51 at the center of the air slider 51 in the Z direction. Further, the holder support 54 is supported by the connecting plate 53 at the center in the Z direction of the connecting plate 53. Therefore, the load from the holder support 54 is applied to the connecting plate 53 at the center in the Z direction of the connecting plate 53 as indicated by an arrow 62. Further, the load from the connecting plate 53 is applied to the air slider 51 at the center in the Z direction of the air slider 51 as indicated by an arrow 61. That is, the upper surface of the portion protruding upward of the air slider 51 is a portion that receives a load. On the other hand, the mask holder 7 is supported by the holder support 54 at the end in the Z direction.

  If a rotational moment load as shown by an arrow 63 is applied to the mask holder or the like, the mask holder 7 will fall back and forth (Z direction). Then, as shown in FIG. 4, when tilted by the angle θ, a deviation in the Y direction by ΔY = 1 · sin θ occurs. Here, l is the distance between the pattern surface of the mask and the center of the connecting plate 53 in the Z direction. That is, l is the distance between the pattern surface of the mask and the position where the load in the vertical direction of the air slider 51 is applied to the connecting plate 53. If the mask is inspected with a positional shift in the Y direction, the mask pattern is imaged at different positions. Therefore, there is a risk of erroneous detection. Furthermore, if the mask holder 7 falls down beyond the allowable range, the gap between the air slider 51 and the guide shaft 52 disappears, and so-called galling occurs. In addition, in the above description, although the description has been given of the back-falling in which the mask holder 7 is tilted backward, the same problem may occur in the case of the front-falling in which the mask holder 7 is tilted forward. Unless otherwise specified, the −Z direction is the forward direction and the + Z direction is the backward direction. Therefore, in the mask holder, the CCD camera head side in FIG. 1 is the rear surface, and the opposite side to the CCD camera head 3a is the front surface. 4 and 5 can prevent galling occurring between the connecting plate 53 and the holder support 54. Therefore, the inclination angle θ can be easily adjusted.

  In the present invention, in order to prevent the mask holder from falling forward and backward, a fall prevention mechanism 70 is provided as shown in FIG. The fall prevention mechanism 70 will be described below. The fall prevention mechanism 70 includes a glass rail 71, an air pad 72, a holder clamping tool 73, a prism 77 and a rail support 78. The configuration of the fall prevention mechanism 70 will be described with reference to FIGS. FIG. 6 shows an example in which the mask 6 is disposed on the front surface of the mask holder 7.

  A glass rail 71 is provided on the upper side of the mask holder 7 along the X direction. A pair of air pads 72 are provided to face the XY plane of the glass rail 71. The air pads 72 are provided on both the front side and the rear side, respectively. That is, the air pad 72 is disposed so as to sandwich the glass rail 71 in the Z direction. The air pad 72 can eject air to the glass rail 71. That is, the air pad 72 ejects air from the side surface to the glass rail. Due to the air ejected from the air pad 72, a minute gap is generated between the glass rail 71 and the air pad 72. Thereby, the air pad 72 is supported by non-contact. The air pad 72 slides in the X direction while maintaining this minute gap. A holder clamping tool 73 is attached to the front side, that is, the air pad 72 in the −Z direction. This holder clamping tool 73 is attached to the front surface of the mask holder 7. A lever 74 is attached to the rear side, that is, the air pad 72 in the + Z direction. A holder clamping tool 73 is attached to the side surface of the lever 74 with a screw 79. That is, the mask holder 7 is held between the holder holding tool 73a and the holder holding tool 73b.

  Thus, the air pad 72b and the holder clamping tool 73b are provided on the front surface of the mask holder 7. An air pad 72a and a holder holding tool 73a are provided on the rear surface of the mask holder 7. That is, the holder clamping tool 73 is attached to each of the pair of air pads 72. And the upper part of the mask holder 7 is clamped by a pair of holder clamping tools 73. The air pad 72 blows air toward the glass rail 71. The position where the force pushing the glass rail 71 by the air from the air pad 72 a and the force pushing the glass rail 71 by the air from the air pad 72 b balance is the upper position of the mask holder 7. Therefore, it is possible to prevent the mask holder 7 from falling as shown in FIG. That is, when the mask holder 7 is about to fall forward, the gap between the air pad 72a and the glass rail 71 is narrowed. The air pressure in the space between the glass rail 71 and the air pad 72a increases. Therefore, the force from which the air from the air pad 72a pushes the glass rail 71 becomes strong, and the force that the mask holder 7 tends to fall forward can be supported. Thereby, it is possible to prevent the mask holder 7 from falling forward.

  On the other hand, when the mask holder 7 is about to fall backward, the gap between the air pad 72b and the glass rail 71 is narrowed. The air pressure in the space between the glass rail 71 and the air pad 72b increases. Therefore, the force from which the air from the air pad 72b pushes the glass rail 71 becomes strong, and the force that the mask holder 7 tends to fall backward can be supported. Thereby, it is possible to prevent the mask holder 7 from falling backward. As described above, the air ejected from the air pad 72 generates a force between the air pad 72 and the glass rail 71 to support the mask holder 7 to fall down due to the rotational moment load. And if the gap between the air pad 72 and the glass rail 71 becomes narrow, this supporting force will become strong. By utilizing the force generated by the jet of air, it is possible to effectively prevent the mask holder 7 from falling down. Furthermore, by providing the air pads 72 on the front side and the rear side of the mask holder 7, it is possible to prevent the front and rear falls.

  In the present invention, the mask holder 7 is disposed on the front side (−Z side) of the holder support 54. A structure that is supported by the air slider 51 and moves as the air slider 51 moves is referred to as a moving body. That is, the moving body includes a connecting plate 53, a holder support 54, a mask holder 7, a mask 6, an air pad 72, a holder holding tool 73, a lever 74, a correction motor 75, a cam 76, and a screw 79. Of course, the moving body may include other components. Here, the mask holder 7 is disposed in the −Z direction with respect to the portion receiving the load of the air slider 51. Therefore, the center of gravity of the moving body is in front of the center of the air slider 51 in the Z direction. That is, the position of the center of gravity of the moving body in the Z direction is in front of the position of the load applied to the air slider 51. In this case, the mask holder 7 tends to fall forward. Therefore, it is preferable that the air pressure of the air pad 72a is higher than the air pressure of the air pad 72b. Thereby, it can prevent effectively that the mask holder 7 falls down. Thus, it is preferable to increase the air pressure of the air pad 72 corresponding to the direction in which the mask holder 7 easily falls. In other words, in the pair of air pads 72, it is preferable that the air pressure of the air pad 72a on the side where the air slider 51 of the mask holder 7 receives the load is higher than the air pressure of the air pad 72b on the opposite side.

  The force for supporting the mask holder 7 to fall is determined by the air pressure from the air pad 72 and the air ejection area of the air pad. The air pressure is determined by the amount of air ejected from the air pad and the gap between the air pad 72 and the glass rail. The air ejection area is determined by the size and number of exhaust holes. For example, when the gap between the air pad 72a and the glass rail 71 is 3 μm, the air ejection amount and the ejection area are set so that the supporting force is 5 kgf. Thereby, even when a rotational moment load is applied, the mask holder 7 can be supported. Of course, the force for supporting the mask holder 7 to fall can be set to a desired value according to the weight and size of the mask holder 7 and the like.

  Thus, in the present invention, the two air pads 72 are provided on the top of the mask holder 7 so as to sandwich the glass rail 71 provided along the traveling direction. In other words, two air pads 72 that face in a direction (Z direction) perpendicular to the traveling direction (X direction) are provided, and these two air pads 72 are arranged on both sides of the glass rail 71. Holder holding tools 73 for holding the mask holder 7 are attached to the two air pads 72, respectively. Therefore, the mask holder 7 is moved along the glass rail 71. Thereby, the mask holder 7 can be moved with high linearity by the linear guide device 50 provided in the lower part of the mask holder 7. Therefore, an accurate inspection can be performed.

  Note that there may be a displacement in the Z direction between the glass rail 71 and the linear guide device 50. That is, there may be a difference in the position in the Z direction above and below the mask holder 7 due to the difference between the position of the glass rail 71 in the Z direction and the position of the linear guide device 50. In this case, the upper and lower portions of the mask holder 7 move in a state where they are in different positions in the Z direction. The mask holder 7 moves in a state where it is inclined by a certain angle. That is, the mask holder 7 moves in a state where it is tilted forward or backward by an angle based on the positional deviation in the Z direction. In order to prevent this, in the present invention, a holder holding tool 73b having a leaf spring is provided on the front side of the glass rail 71.

  The leaf spring constituting the holder clamping tool 73b is attached so as to push the air pad 72b and the mask holder 7 by its elastic force. And this leaf | plate spring functions as a parallel link. The leaf spring is not deformed when the upper and lower sides of the mask holder 7 are at the same position. In this case, the mask holder 7 is arranged in parallel with the vertical direction in a normal state where the leaf spring is not deformed. When a difference occurs in the position in the Z direction above and below the mask holder 7, the leaf spring is deformed. In this case, the side surface of the glass rail 71 and the side surface of the mask holder 7 are made parallel by the elastic force of the leaf spring. The side surface of the mask holder 7 is pushed by the elastic force of the leaf spring, and the mask holder 7 is in a state parallel to the vertical direction. Thereby, the mask holder 7 can be moved in the X direction in a state where the side surface of the glass rail 71 and the side surface of the mask holder 7 are parallel.

  Further, in the present invention, a position correction mechanism 80 that corrects a positional deviation in the Y direction caused by the undulation of the glass rail 71 is provided. That is, if the side surface of the glass rail is not exactly parallel to the X axis, the mask holder 7 cannot move parallel to the X axis. In other words, when the glass rail 71 is bent, if the position of the mask holder 7 in the X direction is changed, the position of the upper portion of the mask holder 7 in the Z direction is changed. At this time, the mask holder 7 moves in a state where the mask holder 7 is inclined by a minute angle in accordance with the positional deviation. In this case, as shown in FIG. 4, a positional shift occurs in the Y direction. A position correction mechanism for correcting this displacement will be described with reference to FIG. The position correction mechanism 80 includes a lever 74 attached to the holder holding tool 73a, a correction motor 75, a cam 76, and a screw 79.

  A lever 74 is attached to the air pad 72 a on the rear side of the glass rail 71. The air pad 72 a is attached to the top of the lever 74. The lever 74 extends below the air pad 72a and is bent once in the middle thereof. That is, the lever 74 attached to the air pad 72a extends downward, bends in the + Z direction once in the middle, and extends downward again.

  A cam 76 is attached below the portion bent in the + Z direction. The cam 76 is an eccentric cam or a constant velocity cam, and changes the rotational motion of the correction motor 75 to a reciprocating motion. The cam 76 is attached so as to contact the side surface of the lever 74. Thereby, the position of the lower portion of the lever 74 is regulated by the rotation of the cam 76. The cam 76 is provided with a correction motor 75. By driving the correction motor 75, the cam 76 rotates. When the cam 76 rotates, the position of the lever 74 in the Z direction is displaced. That is, when the cam 76 is rotated by the correction motor, the contact position between the cam 76 and the lever 74 is shifted in the Z direction. Thereby, the lower part of the lever 74 can be displaced in the + Z direction and the −Z direction.

The lever 74 is attached to the holder holding tool 73a with a screw 79 at the bent portion. The lever 74 rotates around the screw 79 with respect to the holder holding tool 73a. That is, when the lower portion of the lever 74 is pushed in the + Z direction, the upper portion of the lever 74 is displaced in the −Z direction. On the other hand, when the lower portion of the lever 74 is pulled in the −Z direction, the upper portion of the lever 74 is displaced in the + Z direction. Therefore, the position of the upper portion of the lever 74 is displaced according to the rotation of the correction motor 75. When the position of the upper portion of the lever 74 is displaced, the gap between the air pad 72a attached to the lever 74 and the glass rail 71 changes. That is, the air pad 72a follows the displacement of the upper portion of the lever 74 and moves in the Z direction. Thereby, the gap between the air pad 72a and the glass rail 71 changes. Due to the change in the gap, the undulation of the glass rail 71 is canceled. That is, when the air pad 72 moves to a position where the glass rail 71 shifts in the −Z direction, the cam 76 is rotated so as to move the air pad 72a in the −Z direction. Thereby, the air pressure between the air pad 72 a and the glass rail 71 becomes higher than the air pressure between the air pad 72 b and the glass rail 71. Therefore, the air pad 72a has a stronger force to press the glass rail 71 than the air pad 72b. Thereby, the upper part of the mask holder 7 is displaced to the rear side (+ Z side). Therefore, the undulation of the glass rail 71 can be corrected. It is possible to prevent the rearward tilt that occurs when the glass rail 71 is displaced in the -Z direction.

  On the other hand, when the glass rail 71 is displaced in the + Z direction, the cam 76 is rotated so as to move the air pad 72a in the + Z direction. Thereby, the air pressure between the air pad 72 a and the glass rail 71 becomes lower than the air pressure between the air pad 72 b and the glass rail 71. Therefore, the force with which the air pad 72a pushes the glass rail 71 is weaker than that of the air pad 72b. Thereby, the upper part of the mask holder 7 is displaced to the front side (−Z side). Therefore, the undulation of the glass rail 71 can be corrected. It is possible to prevent the forward tilt that occurs when the glass rail 71 is displaced in the + Z direction.

  As described above, the tilt prevention mechanism 70 and the position correction mechanism 80 can correct the positional deviation of the upper portion of the mask holder due to the undulation of the glass rail 71. Therefore, it is possible to prevent the mask from collapsing due to the positional deviation of the upper part of the mask holder. Therefore, the vertical displacement of the mask can be prevented and the inspection can be performed accurately.

  The glass rail 71 can be attached, for example, as shown in FIG. FIG. 8 is a diagram for explaining a configuration for attaching the glass rail 71, and is a schematic view of the surface plate 2 as viewed from above. The glass rail 71 is provided in the center of the surface plate 2 along the X direction. Square columns 77 are provided at both ends and the center in the X direction. That is, three prisms 77 are provided at substantially equal intervals. A glass rail fixture 78 is provided on the top of the prism 77 as shown in FIG. The glass rail 71 and the prism 77 are fixed by the glass rail fixture 78. The prisms 77 are preferably arranged on both sides of the glass rail 71 in the Z direction. Thereby, the curvature of the glass rail 71 can be prevented. The prism 77 is made of granite or the like, like the prism 1 for the head.

  The control of the fall prevention mechanism 70 and the position correction mechanism 80 will be described with reference to FIG. FIG. 9 is a diagram schematically illustrating a control system of the linear guide device, the fall prevention mechanism, and the position correction mechanism. 41 is a processing device, 42 is a linear motor driver, 43 is a linear motor controller, 44 is a linear motor yoke, 45 is a linear motor coil, 82 is a correction motor driver, 83 is a gear, 84 is a correction motor controller, and 85 is a memory. .

  As described above, in order to move the mask holder 7 using the linear guide device 50, a linear drive mechanism including the linear motor yoke 44, the linear motor coil 45, and the linear motor driver 42 is provided. The linear motor yoke 44 is fixed to the surface plate 2 along the X direction. In the linear motor yoke 44, N poles and S poles are alternately arranged at a predetermined pitch along the X direction. A current flows through the linear motor coil 45 by the current supplied from the linear motor driver 42. The magnetic field generated in the linear motor coil 45 changes according to this current, and the linear motor coil 45 moves along the X direction based on the magnetic field in the linear motor yoke 44. The linear motor coil 45 is attached to the mask holder 7 or the like, for example. Therefore, when the linear motor coil 45 moves, the mask holder 7 moves. In addition, since the same thing as the conventional can be used about a linear motor, it abbreviate | omits about detailed description.

  The processing device 41 is a normal personal computer or the like, and includes a central processing unit (CPU) that performs predetermined processing and a storage device such as a memory or a hard disk that stores captured image data. The processing device 41 includes a linear motor controller 43 that controls the linear motor driver 42, a correction motor controller 84 that controls the correction motor driver 82, and a memory 85 that stores correction information. The processing device 41 can control the linear motor driver 42 to move the mask holder 7 to a predetermined position. For example, when the mask holder 7 is moved in the + X direction, a CW pulse is output to the motor driver 42, and when the mask holder 7 is moved in the -X direction, a CCW pulse is output. The linear motor driver 42 controls the current that flows through the linear motor coil 45 based on the CW pulse or the CCW pulse. The linear motor coil 45 is driven by the CW pulse or the CCW pulse, and the mask holder 7 moves to a predetermined position. Further, the processing device 41 stores the current position of the mask holder 7 in the X direction.

  The processing device 41 further includes a correction motor controller 84. The correction motor controller 84 of the processing device 41 controls the correction motor driver 82 based on the position of the mask holder 7 in the X direction. That is, the side surface of the glass rail 71 may not be flat due to the undulation. In this case, when the position of the mask holder 7 in the X direction changes, the position of the glass rail in the Z direction changes. The correction motor controller 84 of the processing device 41 controls the correction motor driver 82 so as to cancel this swell and move the mask holder 7 with high straightness. Specifically, the memory 85 of the processing device 41 stores the position of the mask holder 7 in the X direction and the positional deviation at that position in association with each other. This positional deviation amount is a value to be corrected. Here, the displacement in the Z direction is corrected by rotating the correction motor 75 as described above.

  A gear 83 is provided between the correction motor 75 and the cam 76. The gear 83 changes the rotation speed of the correction motor 75. The rotation of the correction motor 75 is transmitted to the cam 76 with the rotation speed changed by the gear 83. As a result, the cam 76 can move the upper portion of the lever 74 in the Z direction as shown in FIG. For example, the processing device 41 outputs a CW pulse when moving the upper portion of the lever 74 in the + Z direction, and outputs a CCW pulse when moving the upper portion of the lever 74 in the −Z direction. Here, the correction motor driver 82 can change the rotation direction of the correction motor 75 and change the moving direction of the lever 74 depending on whether it is a CW pulse or a CCW pulse. Then, the correction motor driver 82 drives the correction motor 75 according to the number of pulses. Thereby, rotation of the cam 76 can be controlled. Here, the number of pulses corresponding to the positional deviation in the Z direction is stored in the processing device 41. Therefore, the processing device 41 outputs a control pulse corresponding to the position of the mask holder 7 in the X direction.

  In this way, correction information in which the position in the X direction and the number of pulses corresponding to the amount of displacement at that position are associated with each other is stored in the processing device 41. The processing device 41 controls the linear motor driver 42 and the correction motor driver 82 based on the correction information. Specifically, the correction motor 75 is controlled to rotate in a predetermined manner according to the position moved by the linear motor driver 42. That is, the correction motor driver 82 rotates the correction motor 75 so that the position of the lever 74 in the Z direction is determined according to the position moved by the linear motor driver 42. Thereby, according to the position in the X direction, the position in the Z direction is determined so that the undulation of the glass rail is canceled.

  The correction information in which the position in the X direction described above is associated with the number of pulses corresponding to the displacement amount at the position can be obtained by inspecting a reference mask. That is, the inspection is performed once or a plurality of times without correction. Then, when a positional deviation in the Y direction has occurred in the captured image, the X coordinate and the positional deviation amount in the Y direction at that position are obtained. From the positional deviation amount in the Y direction, the positional deviation amount in the Z direction of the glass rail 71 is calculated. That is, when the glass rail 71 is displaced in the Z direction, the position of the inspection target mask in the Y direction is displaced as shown in FIG. Therefore, the positional deviation in the Z direction of the glass rail 71 can be calculated from the positional deviation in the Y direction of the image captured without correction. Then, the mask holder 7 is moved by one stroke in the X direction, and the positional deviation in the Y direction is calculated at predetermined intervals. Then, the change in the position in the Z direction for one stroke is sequentially calculated from the position shift in the Y direction thus calculated. Then, the change in the position in the Z direction during one stroke and a value obtained by converting the position change into an output pulse are stored in the processing device 41. This position change and the value converted into the output pulse are stored in the memory 85 in association with the position in the X direction. The correction motor is controlled based on the correction information stored in the memory 85. By controlling in this way, the mask holder 7 can be moved with good straightness. Therefore, an accurate inspection can be performed.

  In the present invention, the object to be inspected may be other than a mask and used in an inspection apparatus other than a mask inspection apparatus. For example, a semiconductor device substrate or a display device substrate can be inspected. That is, the present invention can be used for an inspection apparatus having a linear guide device that slides horizontally in a state where the substrate is vertically arranged. The linear guide device 50, the linear drive mechanism, the fall prevention mechanism 70, and the position correction mechanism 80 illustrated in the above description are examples, and configurations other than those illustrated may be used. The gas supplied to the air slider 51 and the air pad 72 may be a gas other than air.

It is a perspective view which shows typically the structure of the test | inspection apparatus concerning this invention. It is a perspective view which shows typically the structure of the test | inspection apparatus concerning this invention. It is a side view which shows typically the structure of the air slider used for the linear guide apparatus of the test | inspection apparatus concerning this invention, and the component attached to it. It is sectional drawing which shows typically the structure of the linear guide apparatus used for the test | inspection apparatus concerning this invention. It is sectional drawing which shows a part of structure in the inspection apparatus concerning this invention. It is sectional drawing which shows typically the structure of the test | inspection apparatus concerning this invention. It is a top view which shows typically the structure of the test | inspection apparatus concerning this invention. It is a figure for demonstrating the structure for attaching the glass rail of the test | inspection apparatus concerning this invention. It is a figure which shows typically the control system of the inspection apparatus concerning this invention.

Explanation of symbols

1 prism for head, 2 surface plate, 3a CCD camera head,
4 Balance weight (counter weight), 5 wires, 6 masks,
7 mask holder, 9 first reference surface, 10 second reference surface, 11 air pad,
12 right-angle stage for head, 16 head motor, 18 motor stage 30 horizontal movement mechanism, 40 linear drive mechanism, 41 processing device,
42 linear motor driver, 43 linear motor controller,
44 linear motor yoke, 45 linear motor coil, 50 linear guide device,
51 air slider, 52 guide shaft, 53 connecting plate, 54 holder support,
70 fall prevention mechanism, 71 glass rail, 72 air pad,
73 Holder clamping tool, 74 lever, 75 correction motor, 76 cam, 77 prism 78 rail support, 79 screw, 80 position correction mechanism, 82 correction motor driver 83 gear, 84 correction motor controller, 85 memory

Claims (8)

An inspection apparatus that has an air slider that floats by ejecting air, and that performs inspection by detecting light from an object to be inspected while moving the air slider in a horizontal direction while floating.
A pair of guide shafts fixed along the first direction;
An air slider provided between the pair of guide shafts so as to be movable along the first direction, wherein the air is jetted to the guide shafts to generate a minute gap between the guide shafts. A slider,
A drive mechanism for moving the air slider in a first direction;
A holder that moves together with the air slider and holds the object in a vertical direction;
A photodetector for detecting light from the inspected object;
A rail provided on an upper side of the holder and provided along the first direction;
A pair of air pads provided so as to sandwich the rail from a second direction substantially perpendicular to the first direction;
An inspection apparatus provided with a pair of holder clamping tools provided corresponding to the pair of air pads and arranged so as to sandwich the upper part of the holder. At least one of the pair of holder clamping tools has a leaf spring,
The inspection apparatus according to claim 1, wherein the leaf spring pushes the upper part of the mask holder in the second direction to move the holder in a state parallel to the vertical direction.   The inspection apparatus according to claim 1, wherein the holder is disposed at a position different from a portion where the air slider receives a load in the second direction. A holder support that is provided above the air slider and supports the holder;
An end of the holder support in the second direction is formed so as to protrude upward,
The inspection apparatus according to claim 3, wherein the holder is disposed at a position different from a portion where the air slider receives a load by disposing the holder in the protruding portion. Two air sliders are provided so as to be arranged at least at the end of the holder, respectively.
A connecting plate for connecting the two air sliders;
The inspection apparatus according to claim 4, wherein the holder support is attached to the connection plate. At least part of the lower surface of the holder support is a curved surface;
The inspection apparatus according to claim 4, wherein the holder is provided so as to be inclined with respect to the air slider.   The air pressure of an air pad arranged on the side of the pair of air pads on which the air slider of the holder receives a load is higher than the air pressure of an air pad arranged on the opposite side. The inspection device according to claim 1. The position correction mechanism which displaces the position in the said 2nd direction of at least one of a pair of said air pad, and correct | amends the position shift of the said to-be-tested object to the perpendicular direction is provided. Inspection device.

Images