JPH11237596A - Inspection stage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make reducible the position deviation between the electrode of a body to be inspected and a probe even when an unbalanced load by the probe is applied onto a receiving base by transmitting a load acting on the receiving base to a supporting means with a first connection means on a rotation center side and plural second connection means around it. SOLUTION: When the electrode of a single tab type liquid crystal substrate is pressed by the probe, since a pressing force acts on the two adjacent edge parts of the liquid crystal substrate, an unbalanced load acts on a Z stage 26 and a receiving base 60. However, in this stage, a Z slider 88 transmits the load acting on it to the receiving base 60 by a Z driving mechanism arranged at the corner part of a virtual square analogous to the liquid crystal substrate, so that inclination and deflection are prevented. Also, since the receiving base 60 transmits the load acting on it to a θ base and Y slider 46 by a bearing 62 on the center side and plural curve guides 64 around it, the inclination and the deflection are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection stage used in a current test apparatus for a flat object to be inspected such as a liquid crystal substrate.

[0002]

2. Description of the Related Art As one type of liquid crystal display panel having a rectangular shape, there is a so-called single tab type in which a plurality of electrodes are provided at two edges corresponding to two adjacent sides of the rectangle.

Such a single-tab liquid crystal display panel generally includes an inspection stage (measurement stage) having a receiving table for directly or indirectly receiving a work table for the liquid crystal display panel to be inspected, and a panel mounting stage. The inspection is performed by an inspection device (measurement device) using a probe unit having a plurality of probe blocks supported at portions corresponding to two adjacent sides.

[0004] In order to position the liquid crystal display panel with respect to the probe unit, the inspection stage moves the liquid crystal display panel in two directions (X and Y directions) orthogonal to each other in a plane parallel to the liquid crystal display panel and at right angles to the panel. Displaced in the Z direction and displaced around the Z axis. Therefore, the inspection stage includes three stages of X, Y, and Z for displacing the pedestal three-dimensionally, and a θ stage for displacing the pedestal angularly around the Z axis.

[0005] The liquid crystal display panel is moved in the X and Y directions by an inspection stage while being separated from the tip (tip) of a probe provided in the probe block by about several mm, and is angularly rotated about the Z axis. , The electrode is positioned with respect to the probe, and then further moved in the direction of the Z-axis, whereby the electrode is pressed against the probe tip of the probe, and electricity is supplied in that state.

In this type of inspection apparatus, at the time of inspection,
Since two adjacent edges of the liquid crystal display panel are simultaneously pressed against the tips of a large number of probes, the pressure applied by one probe to the liquid crystal display panel is small, but the pressure applied by all the probes to the liquid crystal panel is large. Therefore, an unbalanced load resulting from the pressing by the probe acts on the pedestal.

However, in the conventional inspection stage, the pedestal is merely supported on the Z stage by a bearing such as a cross roller at a portion near the center of rotation of the pedestal. As a result, the position where the probe is pressed against the electrode of the liquid crystal display panel is displaced, so that the electrode and the probe often do not come into electrical contact.

The electrical non-contact state between the electrode and the probe is as follows:
Since the electrodes of the liquid crystal display panel are very small, this occurs when the cradle is slightly tilted or bent. Therefore, even if the pedestal is slidably mounted on the Z stage in the Z direction by a guide means such as a linear guide at a plurality of locations on the outer peripheral portion thereof, the inclination of the pedestal may cause a non-contact state between the electrode and the probe. Or the bending and the displacement between the electrode and the probe are caused by a slight play existing in the linear guide.

[0009] The above-mentioned problems are not only an inspection apparatus (test apparatus) for a liquid crystal substrate such as a liquid crystal display panel and a glass substrate before enclosing the liquid crystal, but also an energization test of another flat object to be inspected such as a semiconductor wafer. It also occurs in equipment.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to suppress the inclination or flexure of the pedestal at that time even if the eccentric load by the probe acts on the pedestal, thereby displacing the electrode of the DUT and the probe. Is to be as small as possible.

[0011]

An inspection stage according to the present invention comprises a .theta. Stage for displacing a flat object to be inspected around a Z axis perpendicular to the stage, and a support for rotatably receiving the .theta. Stage around the Z axis. Means. The θ stage comprises a receiving table for directly or indirectly receiving the object to be inspected, first connecting means for connecting the receiving table to the support means so as to be rotatable about the Z axis, and first connecting means. A plurality of second coupling means disposed around the means and spaced about the Z axis for coupling the cradle to be angularly rotatable about the Z axis; and Drive mechanism for displacing around the.

The load acting on the cradle is not only transmitted to the support means by the first coupling means on the rotation center side, but also
It is transmitted to the support means by a plurality of second coupling means around it. Therefore, even if the eccentric load acts on the cradle, the inclination or bending of the cradle caused by the eccentric load is caused by the first coupling means on the rotation center side and the one or more second coupling means around the first coupling means.
Are prevented by the connecting means. When the inclination or the bending of the pedestal is suppressed as described above, the relative displacement between the electrode and the probe is reduced, and the contact state between the electrode and the probe is stably maintained.

Each of the second coupling means can be arranged at a corresponding corner corresponding to a corner of the virtual rectangle. Thus, since the electrode portions of the test object are usually provided on two or more adjacent sides of the rectangle, the inclination or bending of the cradle due to the unbalanced load can be further reduced.

Each of the second coupling means is disposed on one of the support means and the pedestal and extends in an arc shape, and is disposed on the other of the support means and the pedestal and slidably engages the guide rail. Guide provided. Thereby, without hindering the rotational movement of the cradle,
The inclination or bending of the cradle due to the unbalanced load can be suppressed to be small.

The .theta. Drive mechanism comprises a .theta. Motor disposed on a support means, a lead screw rotated by the .theta. Motor and extending in a tangential direction of a virtual circle around the Z axis, and a lead screw. A lead nut screwed into the screw and a link connecting the lead nut to a receiving base can be provided. Thus, the pedestal is angularly rotated by the linear movement of the lead nut. For this reason, since most of the θ drive mechanism can be arranged outside the rotation area of the receiving table, maintenance management becomes easy. Further, as compared with a mechanism in which the cradle is rotated by the eccentric cam and the spring force, a cam surface which greatly affects the accuracy of the θ control is not used, so that the accuracy of the θ control is remarkably improved.

The link can be pivotally connected to the cradle and the lead nut at one and the other two spaced apart in the longitudinal direction of the lead screw, respectively, about an axis parallel to the Z axis. This makes it possible to arrange all the remaining portions of the θ drive mechanism except for the vicinity of the link outside the rotation area of the receiving stand, so that maintenance management becomes easier and the accuracy of the rotation angle control of the receiving stand is improved. Is more improved.

Further, the apparatus includes a Z stage for directly or indirectly receiving the object to be inspected, and the Z stage has a Z
A Z slider movably received in the direction of the axis;
A plurality of Z drive mechanisms that are synchronously driven to displace the slider in the direction of the Z axis; and wherein each Z drive mechanism can be arranged at a corner of a virtual rectangle. Thereby, even if an eccentric load caused by the relative pressing of the electrode and the probe acts on the Z slider, the inclination or bending of the Z stage, particularly the Z slider, caused by the bias load is caused by the Z slider disposed at each corner of the rectangle. It is prevented by the drive mechanism.

Each Z drive mechanism has a hollow electric motor arranged in a receiving table, a lead screw whose one end is received in the hollow part of the electric motor and whose other end is connected to the Z slider, and which is screwed to the lead screw. And a lead nut disposed on the cradle or the electric motor. Accordingly, the height of the Z stage and thus the entire inspection stage is reduced by at least the dimension of the lead nut received in the hollow portion.

[0019]

1 to 3, an inspection stage 10 is used for a lighting inspection of a square liquid crystal substrate. In the illustrated example, the liquid crystal substrate is a single-tab liquid crystal display panel having a plurality of electrodes on each of edges corresponding to two adjacent long and short sides of a quadrangle, and is mounted on the work table 12. . The inspection probe unit is arranged above the work table 12 such that the probe faces the electrode of the liquid crystal substrate on the work table 12.

Hereinafter, in order to facilitate understanding, in both the inspection stage 10 and the liquid crystal substrate, the direction of the long edge (left-right direction) of the liquid crystal substrate is referred to as the X direction, and the axis thereof is referred to as the X axis. The direction of the short edge of the substrate is Y
The direction and the axis are called the Y-axis, the direction perpendicular to the liquid crystal substrate is called the Z-direction, and the axis is called the Z-axis.

The liquid crystal substrate is mounted on a work table 12, and the work table 12 is moved by the inspection stage 10 in three directions of X, Y and Z and angularly about the Z axis. By being rotated, the probe unit is three-dimensionally moved and rotated with respect to the probe unit.

The work table 12 has a chuck top 14 on which a liquid crystal substrate is releasably vacuum-sucked, on a backlight unit 16 supported by the inspection stage 10. The upper surface of the work table 12 (the upper surface of the chuck top 14) is a rectangular mounting surface slightly larger than the liquid crystal substrate.

The inspection stage 10 includes a work table 12
An X stage 20 for moving the work table 12 in the X direction, a Y stage 22 for moving the work table 12 in the Y direction, a θ stage 24 for rotating the work table 12 around the Z axis, and a Z direction And a Z-stage 26 for moving the Z stage.

The Y stage 22, the θ stage 24 and the Z stage 26 are movably supported by the X stage 20, the Y stage 22 and the θ stage 24, respectively.
The stage is moved with the movement of the corresponding stage.
The work table 12 is supported by a Z stage 26.

The X stage 20 is a frame 2 of the inspection apparatus.
8, a rectangular flat X-shaped base (X base) 30 for receiving an X-axis base (X base) 30 and a Y-stage 22.
The shaft slider (X slider) 32 is coupled to the Z-direction by a pair of X-axis linear guides spaced in the Y-direction. Each linear guide for the X axis is provided near the end of the X base 30 and the X slider 32 in the Y direction.

Among the members constituting each linear guide for the X-axis, a long guide rail 34 is attached to the upper side of the X base 30 so as to extend in the X direction, and is slidably fitted to the guide rail 34. A pair of guides 36 each having a U-shaped groove are attached to the lower side of the X slider 32 at intervals in the X direction.

An X drive mechanism for moving the Y stage 22 in the X direction includes an X axis motor 38 disposed on the X base 30.
And a lead screw 40 rotatably supported by the X base 30 so as to extend the side of the X slider 32 in the X direction.
And a lead nut 42 attached to the side of the X slider 32 and screwed to the lead screw 40. The electric motor 38 and the lead screw 40 are assembled to the X base 30 by a bracket 44 including a pedestal portion.

This X drive mechanism is composed of a lead screw 40
Is rotated by the electric motor 38 to move the lead nut 42 in the X direction.
The stage 22 is moved in the X direction. Therefore, the X slider 32 also serves as a Y-axis base (Y base) of the Y stage 22.

The Y stage 22 has a rectangular flat Y-axis slider (Y slider) 46 for receiving the θ stage 24 in the Z direction of the X slider 32 by a pair of Y-axis linear guides spaced in the X direction. It is connected in a spaced state. Each linear guide for the Y-axis is provided near the end of the X slider 32 and the Y slider 46 in the X direction.

Among the members constituting each linear guide for the Y axis, a long guide rail 48 is attached to the upper side of the Y base and X slider 32 so as to extend in the Y direction, and is slidable with the guide rail 48. A pair of guides 50 having a U-shaped groove that fits into
6 are attached to the lower side at intervals in the Y direction.

The Y drive mechanism for moving the Y slider 46 and hence the θ stage 24 in the Y direction includes a Y axis motor 52 disposed on the X slider 32 and a Y base for extending the side of the Y slider 46 in the Y direction. A lead screw 54 rotatably arranged on the X slider 32 and a lead nut 56 attached to the side of the Y slider 46 and screwed with the lead screw 54 are provided. The electric motor 52 and the lead screw 54 are attached to the X slider 32 by a bracket 58 including a pedestal portion.

This Y drive mechanism is composed of a lead screw 54
Is rotated by the electric motor 52 to move the lead nut 56 in the Y direction.
The stage 24 is moved in the Y direction. For this reason, the Y slider 46 also serves as a base for the θ axis of the θ stage 24 (θ base).

The .theta. Stage 24 includes a cradle 60 on a Y-slider 46, a bearing 62 disposed at the center, and a plurality of curved guides 64 disposed circumferentially around the bearing 62 at angular intervals. , And the Z stage 26 is rotatably supported around the Z axis.
Is receiving. The cradle 60 also serves as a Z-axis base (Z base) of the Z stage 26.

The cradle 60 has a short shaft portion 60a and a rectangular flat plate portion 60b which are non-displaceably connected. The Y-slider is mounted on the shaft portion 60a by a bearing 62 so that the flat plate portion 60b faces upward. 46 and a plurality of curved guides 64 in the flat plate portion 60b.
To the Y slider 46.

In the illustrated example, Z 62 is used as the bearing 62.
Although a cross roller ring that receives a load in the direction is used, a general thrust bearing may be used. Each curved guide 64 includes a guide rail 66 extending in an arc shape and one or more guides 68 having a U-shaped groove extending in an arc shape to be slidably fitted with the guide rail 66.
This is a so-called R guide.

In the illustrated example, each of the R guides 64 is arranged at a corner of a virtual rectangle similar to the liquid crystal substrate around the bearing 62, but the center of the radius of curvature is coincident. May be coaxially arranged around the Z axis. Guide rail 66 and guide 68 of each R guide 64
Are coaxially mounted on the upper side of the Y slider 46 and the lower side of the cradle 60 so as to be located on the same imaginary line. As a result, the R guide 64 becomes
Does not hinder the rotation of

The θ drive mechanism for angularly rotating the cradle 60 and thus the Z stage 26 around the Z axis includes a θ axis motor 70 disposed on the Y slider 46, a lead screw 72 rotated by the motor 70, , A lead nut 74 screwed to the lead screw 72, and a link 76 for connecting the lead nut 74 to the receiving stand 60. The electric motor 70 and the lead screw 72 are attached to the Y slider 46 by a bracket 78 such that the lead screw 72 extends in a tangential direction of a virtual circle around the Z axis and is rotatable.

As shown in FIGS. 4 and 5, the lead nut 74 has a plate-like portion 80, and is pivotally movable about an axis extending in the Z direction by a pin 82 at the plate-like portion 80. It is connected to one end of a link 76. The other end of the link 76 is connected to the lower side of the flat plate portion 60b by a pin 84 so as to be pivotable about an axis extending in the Z direction.

The .theta. Drive mechanism converts the rotational movement of the electric motor 70 into linear movement of the lead nut 74 by the lead screw 72 and the lead nut 74, and transmits this linear movement to the pedestal 60 by the link 76 so that the pedestal 60 To the angular rotational motion of. Thereby, the accuracy of the control of the angular rotation movement (θ control) of the cradle 60 is remarkably improved as compared with the mechanism for rotating the cradle by the eccentric cam and the spring force.

As shown in FIG. 6A, for example, when the edge of the flat plate portion 60b of the receiving table 60 is parallel to the lead screw 72, the lead nut 74 is moved in the direction of the arrow by the forward rotation of the electric motor 70. Then, the cradle 60 moves to the position shown in FIG.
As shown in (B), the edge is slightly rotated so that the edge thereof has a small angle with respect to the lead screw 72. When the motor 70 is reversed, the cradle 60 is angularly rotated in the opposite direction.

As described above, when most of the θ drive mechanism is arranged outside the rotation area of the receiving table, maintenance management becomes easy. Further, the link 76 is provided at one of the two positions in the longitudinal direction and at the other, at the receiving stand 60 and the lead nut 7 respectively.
4 so as to be pivotable about an axis parallel to the Z axis, all parts of the θ drive mechanism can be located outside the rotation area of the cradle 60, except near the link 74, Maintenance becomes easier, and the accuracy of the rotation angle control, that is, the θ control, is significantly improved.

The pedestal 60 is connected to the lead screw 7.
2. The θ drive mechanism that rotates using the lead nut 74 and the link 76 does not use a cam surface that greatly affects the accuracy of θ control as compared with the θ drive mechanism that rotates the receiving table by an eccentric cam and a spring force. Therefore, the cradle 60 can be angularly rotated with high accuracy, and the accuracy of θ control is significantly improved.

The Z stage 26 includes a pair of plate-like frames 86 assembled in parallel to the receiving table 60 at intervals in the Y direction and a box-shaped Z slider 88 disposed between the frames 86. With a pair of Z-axis linear guides 90,
The Z slider 88 is connected so as to open downward. As the frame 86, a rectangular tubular member that is open in both the up and down directions may be used.

Of the members constituting each linear guide for the Z-axis, the long guide 92 is attached to the inside of the frame 86 so as to extend in the Z direction, and is fitted to the guide 92 in a slidable manner. A pair of guide rails 94 having a letter-shaped groove are mounted inside a rectangular Z slider 88 at intervals in the Z direction.

The Z slider 88 is displaced in the Z direction with respect to the cradle 60 and the frame 86 by a plurality of Z drive mechanisms driven in synchronization with each other. Each Z drive mechanism is
The slider 88 is disposed at a position corresponding to a corner of a virtual rectangle similar to the liquid crystal substrate in the slider 88. Each Z drive mechanism has an electric motor 96 mounted on the cradle 60.
And a lead screw 98 rotated by an electric motor 96
And a lead nut 10 screwed with the lead screw 98
0.

The electric motor 96 is a so-called hollow servo motor having a hollow rotor, and is assembled to the cradle 60 by the bracket 102. Lead screw 9
Numeral 8 is inserted into the hollow portion of the rotor of the hollow servomotor at one end so as to extend in the Z direction, and is connected to the lower surface of the upper plate portion of the Z slider 88 at the other end. The lead nut 100 is coaxially mounted on the rotor of the electric motor 96. However, the lead nut 100 may be rotatably disposed on the cradle 60 by the bracket 102.

In the Z drive mechanism, when the lead nut 100 is synchronously rotated by the electric motor 96 driven in synchronization, the lead screw 98 is synchronously moved in the Z direction, and the Z slider 88 is synchronized. To move in the Z direction.

At the time of inspection, the liquid crystal substrate is first placed on the work table 12 and then the X stage 20 and the Y stage 2
It is moved in three directions of X, Y and Z by the 2 and Z stages 26 and is rotated angularly about the Z axis by the θ stage 24. As a result, the liquid crystal substrate is three-dimensionally moved with respect to the probe unit and angularly rotated to be positioned. Next, the liquid crystal substrate is raised by the Z stage 26, and each electrode portion is pressed by the probe above it.

When the electrode of the single-tab liquid crystal substrate is pressed by the probe, the pressing force acts on two adjacent edges of the liquid crystal substrate, so that an uneven load acts on the Z stage 26 and the receiving table 60.

However, since the Z slider 88 transmits the load acting thereon to the cradle 60 by the Z drive mechanism disposed at the corner of a virtual square similar to the liquid crystal substrate,
Tilt and deflection are prevented. Further, the pedestal 60 applies the load acting thereon to the θ base / Y slider 4 by the center bearing 62 and a plurality of curved guides 64 therearound.
6, the inclination and the bending are prevented.

As a result, according to the inspection stage 10,
Even if an eccentric load acts on the cradle 60 and the Z slider 88, their inclination and bending are kept small, the relative displacement between the electrode and the probe is reduced, and the contact state between the electrode and the probe is stable. Is maintained. Further, since the Z drive mechanism receives one end of the lead screw 98 in the hollow portion of the hollow motor, the height of the Z stage and thus the entire inspection stage is reduced.

Instead of arranging the R guides at the corners of the square, the R guides may simply be arranged at angular intervals around the Z-axis.
A similar R guide may be further arranged between the four. Similarly, instead of disposing the Z drive mechanism at the corner of the square,
It may only be spaced around the Z axis, and for example, a similar Z drive may be further arranged between the illustrated Z drives.

The present invention is not limited to the above embodiment. For example, the θ stage 24 may be arranged on the Z stage 26. The present invention is applicable not only to a liquid crystal substrate such as a liquid crystal display panel or a transparent substrate (glass substrate) for the same, but also to a display substrate such as a glass substrate for another display panel and an inspection stage of a substrate such as a semiconductor wafer. Can be applied.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of an inspection stage according to the present invention.

FIG. 2 is a plan view of the inspection stage shown in FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is an enlarged plan view near the θ drive mechanism.

FIG. 5 is a sectional view taken along the line 5-5 in FIG. 4;

FIG. 6 is a diagram for explaining a rotation state of a receiving table.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 inspection stage 12 work table 14 backlight unit 16 chuck top 20 X stage 22 Y stage 24 θ stage 26 Z stage 28 frame 30 X base 32 Y base and X slider 46 θ base and Y slider 60 pedestal 60 a pedestal axis Part 60b Flat part of cradle 62 Bearing 64 Curve guide 66 Curve guide guide 68 Curve guide guide rail 70 Electric motor for θ axis 72 Lead screw for θ axis 74 Lead nut for θ axis 76 Link for θ axis 82 84 Pin for pivot connection 86 Frame of Z stage 88 Slider for Z axis 90 Linear guide for Z axis 96 Motor for Z axis (hollow servomotor) 98 Lead screw for Z axis 100 Lead nut for Z axis

Claims (7)

[Claims] 1. A θ stage for displacing a flat object to be inspected around a Z axis orthogonal to the plate, and support means for rotatably receiving the θ stage around the Z axis. A pedestal for directly or indirectly receiving an object to be inspected, first coupling means for coupling the pedestal to the support means so as to be angularly rotatable about the Z axis, and the first coupling A plurality of second coupling means around the means and spaced apart about the Z axis for coupling the cradle to be angularly rotatable about the Z axis; and An inspection stage comprising: a θ drive mechanism for displacing the Z-axis. 2. Each of the second coupling means is arranged at a corresponding corner corresponding to a corner of the virtual rectangle.
The inspection stage according to claim 1. 3. Each of the second coupling means is disposed on one of the support means and the pedestal and extends in an arc shape, and the second coupling means is disposed on the other of the support means and the pedestal and is provided with the guide. The inspection stage according to claim 1, further comprising a guide slidably engaged with the rail. 4. The θ drive mechanism comprises a θ motor disposed on the support means, and a lead screw rotated by the θ motor, the lead extending in a tangential direction of a virtual circle around the Z axis. 4. A screw, a lead nut screwed to the lead screw, and a link connecting the lead nut to the cradle.
Inspection stage described in. 5. The link is pivotally movable about an axis parallel to the Z-axis at one of the two locations spaced apart in the longitudinal direction of the lead screw and at the other, respectively, at the pedestal and the lead nut. Linked,
The inspection stage according to claim 4. 6. A Z slider which directly or indirectly receives the object to be inspected, wherein the Z stage is displaceably received in the direction of the Z axis by the receiving table; A plurality of Z drive mechanisms that are driven synchronously to displace the Z slider in the direction of the Z axis,
The inspection stage according to any one of claims 1 to 5, wherein each Z drive mechanism is disposed at a corner of a virtual rectangle. 7. Each Z drive mechanism includes: a hollow electric motor disposed in the cradle; a lead screw having one end received in the hollow of the electric motor and the other end connected to the Z slider; The inspection stage according to claim 6, further comprising: a lead nut screwed into the lead screw and disposed on the cradle or the electric motor.