JP2000147044A - Device and method for inspecting plate-shaped object to be inspected - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent unbalanced load generated by the probe pressure of a probe unit from acting on a measurement stage by raising a Z-stage by means of a Z-drive source provided on the outside of the measurement stage, by not incorporating the drive mechanism of the Z-stage in the measurement stage. SOLUTION: Alignment between a probe and the electrode of a glass substrate 73 is made by finely adjusting an X-stage, a Y-stage, and a θ-stage. Upon completion of the alignment, four Z-up blocks 116 are raised by synchronously driving four Z-motors 108. When the blocks 116 are raised, the blocks 116 come into contact with and raise Z-up wear plates 100, and a Z-stage 70 rises as a whole. When the wear plates 100 come into contact with Z-up stoppers 124, the rising of the Z-stage 70 is discontinued. When the stage 70 stops, the probe 126 of a probe unit comes into contact with the electrode of a glass substrate 73 on a chuck top 72.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus and an inspection method used for a current test apparatus for a flat inspection object such as a liquid crystal display panel.

[0002]

2. Description of the Related Art As one form of a liquid crystal display panel having a rectangular shape, there is a so-called single tab type in which a large number of electrodes are provided on two adjacent sides of a rectangle.

FIG. 8 is a plan view of a conventional inspection apparatus for inspecting such a single-tab liquid crystal display panel, and FIG. 9 is a front view thereof. In FIG. 9, the inspection apparatus includes a cassette mounting table 10, a loader unit 12, and a measurement unit 1.
4. In FIG. 8, the cassette mounting table 1
0 has two substrate cassettes 16, each of which can accommodate a plurality of liquid crystal display panels. In FIG. 9, a transfer robot 18 is provided in the loader unit 12, and the transfer robot 18 transfers the liquid crystal display panel between the substrate cassette 16 and the measurement unit 14. 8 and 9,
The measuring unit 14 includes a step 20, a control panel 22, a monitor 24, a microscope 26, a probe unit 28, and the like. The probe unit 28 contacts a probe with an electrode on a glass substrate of the liquid crystal display panel.

FIG. 10 is a plan view of a conventional measurement stage provided below the probe unit 28 in FIG. 8, showing a state in which an uppermost chuck top is removed. 11 is a front view of the measurement stage shown in FIG. 10, and FIG. 12 is a cross-sectional view taken along line AA of FIG. In FIGS. 11 and 12, the measurement stages are arranged in order from the bottom, X
An X stage 30 that can move in the direction, a Y stage 32 that can move in the Y direction, a θ stage 34 that can rotate θ around the Z axis, and a Z stage 36 that can move up and down in the Z direction. There is a chuck top 38 on the Z stage 36. The chuck top 38 can fix the glass substrate thereon by vacuum suction. The chuck top 38 is square, and a rectangular glass substrate 39 (see FIG. 12) can be placed in any direction.

When the X motor 40 rotates, the X stage 30
Moves on the base 41 in the X direction. When the Y motor 42 rotates, the Y stage 32 moves on the X stage 30 in the Y direction. When the θ motor 44 (see FIG. 10) rotates, the θ stage 34 rotates around the Z axis on the Y stage 32 by θ.
Rotate. When the Z motor 46 rotates, the Z stage 36 moves up and down on the θ stage 34 in the Z direction. 10, four Z guide bases 48 are fixed to the lower surface of the substantially octagonal Z stage 36 and extend downward. A guide 49 is fixed to the Z guide base 48.
On the other hand, four guide rail posts 50 are fixed to the upper surface of the θ stage 34 and extend upward. A guide rail 52 is fixed to the guide rail posts 50.
A guide 49 of the Z stage 48 is slidably engaged with the guide rail 52. Also, eight reinforcing plates 54 (see also FIG. 12) are fixed to the lower surface of the Z stage 36.

[0006]

When a probe contacts an electrode on a glass substrate, an unbalanced load acts on the glass substrate due to the stylus pressure. As the size of the glass substrate increases, the influence of the unbalanced load becomes significant.
When the chuck top bends due to the unbalanced load, a phenomenon occurs in which the probe comes off the substrate electrode. In order to prevent the chuck top from bending due to such an uneven load, it is necessary to increase the rigidity of the measurement stage. In the conventional example shown in FIGS. 10 to 12 described above, a reinforcing plate 54 is provided on the Z stage 36 in order to increase the rigidity of the measurement stage. In addition, it is necessary to increase the rigidity of the X stage, the Y stage, and the θ stage so that each stage is not bent by the unbalanced load.

If the rigidity of the measuring stage is increased, the entire measuring stage becomes larger and the height of the measuring stage becomes higher. This also increases the manufacturing costs. As the height of the measurement stage increases, the overall height of the measurement section 14 in FIG. 9 also increases, and the manufacturing cost further increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an inspection apparatus and an inspection method which do not need to increase the rigidity of a measurement stage even when an object to be inspected becomes large. Is to do.

[0009]

The inspection apparatus of the present invention has the following (a) to (h). (B) X to base
X stage that can be moved in any direction. (B) A Y stage that is movable on the X stage in a Y direction perpendicular to the X direction with respect to the X stage. (C) A θ stage on the Y stage, which is rotatable around the Z axis perpendicular to the XY plane with respect to the Y stage. (D) A Z stage which is combined with the θ stage so as to be movable only in the Z direction and has no drive source, and which can support a flat plate-shaped test object in parallel to the XY plane. (E)
A base plate fixed to the base; (F) A probe unit fixed to the base plate, the probe unit including a probe capable of contacting an electrode of the device under test. (G) a Z drive source mounted on the base plate. (H) An engagement mechanism driven by the Z drive source, wherein the engagement mechanism is engaged with the Z stage to move the Z stage toward the probe unit in the Z direction. An engagement mechanism capable of bringing an electrode of a test object into contact with the probe.

[0010] The "Z drive source attached to the base plate" in (G) above may be replaced with a "drive source attached to the base".

Further, the inspection method of the present invention provides the following (a) to
(C). (A) A step of mounting a flat test object on a Z stage provided on a measurement stage movable with respect to a base. Here, the Z stage does not have a drive source itself, and can be moved in the Z direction by a Z drive source existing outside the measurement stage.
(B) using the measurement stage, translating the object to be inspected in a two-dimensional direction in an XY plane parallel to the object to be inspected, and rotating the object around a Z axis perpendicular to the XY plane; Aligning the test object with respect to a probe unit. (C) moving the Z stage in the Z direction by the Z drive source, thereby bringing the electrode of the device under test into contact with the probe of the probe unit.

As described above, according to the present invention, the drive mechanism of the Z stage on which the object to be inspected is mounted is not incorporated in the measurement stage, but the Z stage is raised by the Z drive source outside the measurement stage. . As a result, even when an eccentric load due to the stylus pressure acts on the test object, the measuring stage is no longer affected by the eccentric load. Therefore, it is not necessary to increase the rigidity of the measurement stage even when the object to be inspected becomes large.

In the present invention, the flat object to be inspected includes:
Substrates for flat display panels such as liquid crystal display panels and plasma display panels are conceivable.
The present invention is not limited to this, and it is effective to adopt the present invention if the substrate is a relatively large flat plate.

[0014]

FIG. 1 is a front view showing a first embodiment of an inspection apparatus according to the present invention, FIG. 2 is a plan view thereof, and FIG.
FIG. 3 is a sectional view taken along line BB of FIG. 2. FIG. 1 is viewed from the right side of FIG. In FIG. 1, this inspection apparatus includes a probe unit 60 at an upper part and a measurement stage 62 at a lower part. The measurement stage 62 includes, in order from the bottom, an X stage 64 that can move in the X direction and a Y stage that can move in the Y direction.
A stage 66, a θ stage 68 that can rotate θ around the Z axis, and a Z stage 70 that can move up and down in the Z direction are provided. On the Z stage 70 is a chuck top 72. The chuck top 72 can fix the glass substrate 73 of the liquid crystal display panel by vacuum suction thereon. Note that a plane parallel to the glass substrate 73 is an XY plane, and within this XY plane, the X direction and the Y direction are orthogonal to each other. The direction perpendicular to the XY plane is the Z direction.

When the X motor (on the left side of FIG. 1, not shown) rotates, the lead screw 74 (see FIG. 2)
Rotates. In FIG. 3, the lead nut 76 provided on the lower surface of the X stage 64 meshes with the lead screw 74.
Moves in the X direction on a guide rail 78 provided on a stationary base 77.

In FIG. 1, when a Y motor 80 rotates, a Y stage 66 moves on a guide rail 82 in a Y direction via a lead screw and a lead nut.

In FIG. 3, when a .theta. Motor (not shown in FIG. 3) rotates, the lead screw 84 rotates. The lead nut 86 meshing with the lead screw 84 is connected to the θ stage 68 via a link. Thereby, when the θ motor rotates, the θ stage 68 rotates around the Z axis (extending in the vertical direction). stage 68 is rotatably supported on Y stage 66 by bearing 62 at the center and four curved guides 88 at the periphery.

FIG. 4 is an enlarged view of a part of FIG. On the upper surface of the θ stage 68, four Z columns 90 stand, each of which is provided with a Z guide rail 92. The Z stage 70 includes a backlight device 94 and a Z base 96. Four Zs on the side of the Z base 96
A guide 98 is fixed, and the Z guide 98 can move up and down along the Z guide rail 92 described above. As described above, the Z stage 70 is combined with the θ stage 68 so as to be movable only in the Z direction. Note that the Z stage 70 does not have a driving source itself, and is moved by a Z motor existing outside the measurement stage, as described later.

On the two side surfaces (side surfaces parallel to the X axis) of the backlight device 94, a Z-up backing plate 1 having an inverted L-shaped cross section is provided.
00 is fixed. The Z-up backing plate 100 extends in the X direction as shown in FIG.
0 protrudes to both sides from the dimension in the X direction.

Next, the structure of the probe unit will be described. In FIG. 1, four columns 102 stand on a base 77, and a base plate 1
04 is fixed. In FIG. 3, the probe unit 60 is attached to the base plate 104. As shown in FIG. 2, four Z motors 10 are located near the four corners of the central opening 106 of the base plate 104.
8 (corresponding to the Z drive source in the present invention).

In FIG. 4, a Z motor 108 is a hollow motor, and a Z lead nut 110 is fixed to its rotor. The Z lead nut 110 enters a through hole 112 formed in the base plate 104.
On the other hand, the Z lead screw 114 is
10, extends through the through hole 112 from the inside of the Z motor 108 and extends below the base plate 104. An L-shaped Z-up block 116 (corresponding to an engagement mechanism in the present invention) is fixed to a lower end of the Z lead screw 114. A Z-up guide 118 is fixed to a side surface of the Z-up block 116. On the other hand, four Z-up posts 120 are fixed to the lower surface of the base plate 104, and a Z-up rail 122 is fixed to the Z-up posts 120. The Z-up guide 118 of the Z-up block 116 can slide along the Z-up rail 122. When the Z motor 108 rotates, the Z lead nut 110 rotates, the Z lead screw 114 moves up and down, and the Z up block 116 moves up and down. When the Z-up block 116 rises, its tip contacts the Z-up patch 100 from below, and lifts the Z-up patch 100. When the Z-up backing plate 100 is raised, the entire Z stage 70 is raised. A Z-up stopper 124 is fixed to the lower surface of the base plate 104. When the Z-up abutment plate 100 hits the Z-up stopper 124, the Z stage 70 stops rising.

Next, the operation of the inspection apparatus will be described. In FIG. 1, the glass substrate 7 of the liquid crystal display panel is
The measurement stage 62 on which the X.
By moving in the direction, it moves to the measurement unit. At this time,
As shown in FIG. 4, the Z-up backing plate 100 enters between the Z-up block 116 and the Z-up stopper 124. Then, by finely adjusting the X stage 64, the Y stage 66, and the θ stage 68 shown in FIG. When the alignment is completed, in FIG. 4, the four Z motors 108 are driven synchronously to raise the four Z up blocks 116. When the Z-up block 116 rises, it comes into contact with and raises the Z-up backing plate 100, and the entire Z stage 70 rises.
When the Z-up abutment plate 100 hits the Z-up stopper 124, the Z stage 70 stops rising. This is the upper limit position of the Z stage 70. FIG. 5 shows Z
This shows a state where the stage 70 has risen and stopped at the upper limit position. At this time, the probe 1 of the probe unit 60
26 contacts the electrode of the glass substrate 73 on the chuck top 72. When performing the lighting inspection, the backlight of the backlight device 94 is illuminated to check the lighting state of the liquid crystal display panel. When the inspection is completed, the Z-up block 1
Lower 16 Then, the Z stage 70 comes down by its own weight.

As described above, in the present invention, as shown in FIG. 4, the Z stage 70 on which the glass substrate 73 is placed is pulled up by the Z up block 116 driven by the Z motor 108 provided on the base plate 104. There are the following advantages. First, the stylus pressure of the probe does not act on the X stage 64, the Y stage 66, and the θ stage 68 in FIG. The needle pressure is received by the base plate 104 via the Z-up backing plate 100, the Z-up block 116, and the Z motor 108. Therefore, each of the above-described stages 64, 66, 68 does not receive an eccentric load due to the stylus pressure. Therefore, there is no risk that these stages will bend due to an unbalanced load, and there is no need to increase the rigidity of these stages. Second, since the Z stage 70 has no drive mechanism itself, the structure of the Z stage can be simplified. Third, in FIG. 4, the Z stage 70 is supported by the Z-up block 116 near the upper end thereof (at the Z-up backing plate 100 having substantially the same height as the chuck top 72) at the time of contact. Even if the needle pressure acts on the upper chuck top 72, the four Z-up blocks 116 support the needle pressure. Thus, no eccentric load acts below the Z-up backing plate 100, and there is no possibility that the entire Z stage 70 is bent. Therefore, it is not necessary to increase the rigidity of the Z stage 70. At most, it is sufficient that only the chuck top 72 and the top plate of the backlight device 94 have sufficient rigidity so as not to bend themselves. Fourth,
Since the rigidity of all of the XYθZ stages can be made lower than before as described above, the height of the measurement stage can be made lower than before. This makes the measurement stage cheaper.
If the height of the measurement stage can be reduced, the height of the entire inspection apparatus can be reduced as compared with the conventional case, and the entire inspection apparatus can be inexpensive.

FIG. 6 is a front view of the second embodiment of the present invention, and corresponds to FIG. 1 of the first embodiment. FIG. 7 shows FIG.
FIG. 4 is a cross-sectional view of the device of FIG. 3 and corresponds to FIG. 3 of the first embodiment. The difference between the second embodiment and the first embodiment is that the mechanism for lifting the Z stage is directly attached to the base. 6 and 7, the base 7
7, four air cylinders 128 are fixed so as to stand upright. The cylinder rod 130 of each air cylinder 128 can be moved up and down. A Z-up block 132 is fixed to the upper end of each cylinder rod 130. When the cylinder rod 130 moves up, the Z-up block 132 moves up. When the Z-up block 132 rises, it comes into contact with the Z-up backing plate 100 from below, lifts it, and lifts the Z stage 70. Z
When the up contact plate 100 hits the Z-up stopper 124, the Z stage 70 stops there. Parts other than the mechanism for lifting the Z stage are the same as those in the first embodiment.

The present invention is not limited to the above embodiment, and the following modifications are possible. (1) An arbitrary drive source such as an electric motor, an air cylinder, or a hydraulic cylinder can be used as a drive mechanism for raising and lowering the Z-up block. (2) In the above embodiment, the Z-up block is independently attached to each drive mechanism, but a plurality of drive mechanisms arranged in the X direction may drive one Z-up block. For example, in FIG. 6, one Z-up block that is elongated in the X direction may be extended over the upper ends of the cylinder rods 130 of the left and right air cylinders 128. Then, two Z-up blocks are driven by the four drive mechanisms. (3) The Z-up block may have a U-shaped cross section and sandwich the Z-up backing plate from above and below. In this case, even when the Z stage is lowered, the Z-up block pushes down the Z-up abutment plate, and the Z-stage is surely lowered. (4) The mounting height of the Z-up stopper may be adjusted with a screw. By doing so, the upper limit position of the Z stage, that is, the height of the contact position can be adjusted.

[0026]

According to the present invention, the Z stage is raised by a Z drive source provided outside the measurement stage without incorporating the drive mechanism of the Z stage into the measurement stage. It is possible to prevent the measurement stage from bending due to the unbalanced load. This makes it unnecessary to increase the rigidity of the measurement stage even when the object to be inspected becomes large. As a result, the height of the measurement stage can be reduced, and the height of the entire measurement section can be reduced, so that the manufacturing cost of the apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view showing a first embodiment of an inspection device of the present invention.

FIG. 2 is a plan view of the apparatus of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 2;

FIG. 4 is an enlarged view of a part of FIG. 3;

FIG. 5 is a diagram showing a state where the Z stage has risen from the state of FIG. 3;

FIG. 6 is a front view of a second embodiment of the present invention.

FIG. 7 is a sectional view corresponding to FIG. 3 of the apparatus of FIG. 6;

FIG. 8 is a plan view of a conventional inspection device.

9 is a front view of the device of FIG.

FIG. 10 is a plan view of a conventional measurement stage.

FIG. 11 is a front view of the measurement stage of FIG. 10;

FIG. 12 is a sectional view taken along line AA of FIG. 10;

[Explanation of symbols]

 Reference Signs List 60 Probe unit 62 Measurement stage 64 X stage 66 Y stage 68 θ stage 70 Z stage 72 Chuck top 73 Glass substrate 77 Base 90 Z support 92 Z guide rail 98 Z guide 100 Z up patch plate 104 Base plate 108 Z motor 116 Z up Block 126 probe

Claims (4)

[Claims] An inspection apparatus for a flat object to be inspected, comprising the following (a) to (h). (A) An X stage that can move in the X direction with respect to the base. (B) A Y stage that is movable on the X stage in a Y direction perpendicular to the X direction with respect to the X stage. (C) A θ stage on the Y stage, which is rotatable around the Z axis perpendicular to the XY plane with respect to the Y stage. (D) A Z stage which is combined with the θ stage so as to be movable only in the Z direction and has no driving source, and which can support a flat object to be inspected in parallel to the XY plane.
stage. (E) A base plate fixed to the base. (F) A probe unit fixed to the base plate, the probe unit including a probe capable of contacting an electrode of the device under test. (G) a Z drive source mounted on the base plate. (H) An engagement mechanism driven by the Z drive source, wherein the engagement mechanism is engaged with the Z stage to move the Z stage toward the probe unit in the Z direction. An engagement mechanism capable of bringing an electrode of a test object into contact with the probe. 2. The inspection apparatus according to claim 1, wherein the “g drive source attached to the base plate” in (g) is replaced with a “drive source attached to the base”. Inspection equipment. 3. The inspection device according to claim 1, wherein a Z-up abutment plate extending in the X direction is fixed to a side surface of the Z stage, and the engagement mechanism is provided below the Z-up abutment plate. An inspection apparatus characterized by including a Z-up block that can be contacted from above. 4. A method for inspecting a flat object to be inspected, comprising the following steps (a) to (c). (A) A step of mounting a flat test object on a Z stage provided on a measurement stage movable with respect to a base. Here, the Z stage itself has no drive source,
Z driving source existing outside the measuring stage
It can move in any direction. (B) using the measurement stage, translating the object to be inspected in a two-dimensional direction in an XY plane parallel to the object to be inspected, and rotating the object around a Z axis perpendicular to the XY plane; Aligning the test object with respect to a probe unit. (C) moving the Z stage in the Z direction by the Z drive source, thereby bringing the electrode of the device under test into contact with the probe of the probe unit.