JP4288484B2 - Substrate defect correcting apparatus and method, and liquid crystal substrate - Google Patents

Description

  The present invention relates to a substrate defect correcting apparatus and correcting method for correcting defects such as a short-circuit portion of a wiring pattern formed on a liquid crystal substrate or the like.

  For example, the liquid crystal panel has a configuration in which a predetermined gap is formed between two transparent substrates and liquid crystal is sealed in the gap. Of these two transparent substrates, at least one of the substrates is formed with a wiring pattern in which a large number of gate lines and source lines intersect with each other, and pixel electrodes are formed at the intersections to control these electrodes. A predetermined pattern is formed such that a switching element is formed. These patterns, electrodes, switching elements, and the like are formed by repeating processing steps such as development, baking, and etching.

In the above-described processing steps, the processing accuracy in the etching step is extremely important. If accurate etching is not performed, a defect called a short-circuit portion occurs in the wiring pattern. This defect is serious, and if such a defect occurs in the substrate, it cannot be used for a liquid crystal panel. However, such defects can be corrected. In other words, the defect is corrected by removing the excess conductive film at the portion that is a short-circuit portion in the wiring. Therefore, the excess conductive film is removed by irradiating the laser beam limited to the short-circuited portion. In addition, an insulating film is formed at the intersection of the pattern, the pixel electrode, and the switching element. The insulating film may also have a pattern defect. In this case, the laser beam is irradiated to irradiate the pattern. Corrections can be made.
Such a configuration of a substrate defect correcting apparatus using a laser beam is disclosed in, for example, Patent Document 1. This known defect correcting apparatus includes a laser oscillator that is placed on an XY stage so as to face a substrate to be corrected, and is disposed so as to face the substrate, and a laser beam from the laser oscillator is applied to the substrate by an objective lens. It is configured to irradiate the surface. In order to control the irradiation region of the laser beam according to the size of the defect, an electric slit is disposed in the optical path from the laser oscillator to the objective lens to control the laser beam pattern.
JP 2000-231121 A

  By the way, as described above, in order to make the irradiation region of the laser beam irradiated to the substrate variable, a rectangular slit opening in a direction orthogonal to the optical path of the laser beam is formed. In order to make the aperture shape variable, four light shielding plates constituting four sides are provided, and each pair of light shielding plates constituting two opposite sides of each light shielding plate is brought close to and away from the center of the optical axis. It is configured to move in the direction. Accordingly, the slit has a square or rectangular shape.

  Here, when the wiring pattern formed on the substrate is formed in a matrix shape vertically and horizontally on the surface of the substrate, the shape of the slit may be the above-described square or rectangle, but the pattern is vertically and horizontally. It may be inclined with respect to. Therefore, in order to correct the defect in the pattern having such an oblique shape, the XY stage on which the substrate is installed has a horizontal rotation mechanism, and the substrate can be adjusted in three axes. And shall be. In this case, there is a problem that not only the configuration of the stage becomes complicated, but also control becomes difficult.

  Therefore, it is possible to make corrections in an oblique direction by irradiating the laser beam intermittently while moving the XY stage by moving a small amount by moving the XY stage close by making the light shielding plate close. The line of the pattern thus formed has a shape having serrated irregularities. For this reason, not only the time required for correction becomes longer, but also when liquid crystal is sealed in a later process, there is a risk that the liquid crystal will not wrap around sufficiently, or the pattern may be damaged by the action of the sealing pressure. is there.

  The present invention has been made in view of the above points, and can correct a pattern quickly and accurately even if an angle is generated in the pattern or the like, and can perform a finish without unevenness on the edge of the pattern. The purpose is that.

  Therefore, the present invention comprises a slit mechanism for controlling the irradiation area of the laser beam emitted from the laser oscillator to the substrate so that the irradiation area can be varied with respect to a predetermined pattern formed on the substrate surface. The present invention relating to an apparatus for irradiating a laser beam and correcting the pattern of the substrate is characterized in that, as the slit mechanism, the light of the laser beam is formed in order to form an opening through which the laser beam passes. It is composed of four light shielding plates provided in a direction perpendicular to the axis, and each of the light shielding plates can be reciprocated by a predetermined distance by independent reciprocating drive means, and at least two sheets constituting two opposite sides Further, the light shielding plate can be rotated by a predetermined angle on a horizontal plane by independent rotation driving means, and the shape of the opening is changed. That.

Moreover, in order to form the irradiation area of the laser beam irradiated from this laser oscillator, the defect of the pattern formed on the surface of the substrate is corrected by the slit mechanism provided with four light shielding plates. As an invention for the method, by adjusting the position of each movable light-shielding plate of the slit mechanism in the horizontal direction and the rotational direction, the opening formed by the slit mechanism is made to coincide with the defective portion in the pattern on the substrate surface. Then, a laser beam from the laser oscillator is irradiated toward the substrate through the opening, and an excess film member at the defective portion is removed.

  As described above, the slit for controlling the spread of the laser beam can have an arbitrary length and direction, and can effectively correct a predetermined pattern formed obliquely on the substrate surface. In addition, irregularities or the like do not occur in the corrected portion.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, FIG. 1 shows a wiring pattern formed on the substrate 1. In this figure, a wiring pattern is schematically shown, and pixel electrodes, switching elements, and the like are omitted. In FIG. 1, G is a gate line, and D is a drain line. The substrate 1 is formed in a matrix so that the gate lines G and the drain lines D intersect at a fine pitch. In this figure, in this wiring pattern, a defective portion such as a short circuit is indicated by a region F surrounded by diagonal lines.

  Here, a large number of gate lines G are formed in a direction parallel to one side of the substrate 1 with a fine pitch interval, whereas the drain lines D are not parallel to the other one side of the substrate. Many are provided in a state inclined at a predetermined angle. And the defective part F in this board | substrate 1 is the part which the conductive film protruded, for example by etching failure, without being removed completely. If such a defective portion F exists, a short circuit occurs during energization, and this defect must be corrected.

  In order to perform correction for removing the defective portion, the laser unit 2 shown in FIG. 2 is provided. The position between the substrate 1 and the laser unit 2 can be adjusted. In this embodiment, however, the position of the laser unit 2 is adjusted in the XY directions (front and rear and left and right in the horizontal plane). Thus, the substrate 1 is fixedly held. The laser unit 2 side may be fixed and the substrate 1 may be moved in the XY directions. That is, the laser unit 2 is mounted on an XY two-axis robot (not shown) and can be adjusted in the left-right direction (X-axis direction) and the front-back direction (Y-axis direction) on the surface of the substrate 1 while facing the substrate 1. In addition, the structure can be finely positioned.

  In the schematic configuration of the laser unit 2 shown in FIG. 2, 10 is a laser oscillator, 11 is an APC (auto power controller), and the laser beam emitted from the laser oscillator 10 samples its output power by the APC 11. The output power is automatically made constant and output. These constitute a laser beam emitting section.

  The laser beam emitted from the laser oscillator 10 has a predetermined beam diameter, and a slit mechanism that variably controls a slit-like opening through which the laser beam passes so as to be a predetermined irradiation region with respect to the beam diameter. 12 is provided. The laser output unit is configured as described above. Details of the slit mechanism 12 will be described later.

  The laser unit 2 includes a defect observation unit in addition to the laser output unit described above. The defect observing unit is composed of an illumination lamp 13 and a CCD camera 14, and the defect observing unit is for acquiring an image of a portion to be corrected on the surface of the substrate 1. The CCD camera 14 is located on the laser output unit side, and the illumination lamp 13 and the CCD camera are arranged to prevent the laser beam from the laser oscillator 10 from being emitted by the illumination lamp 13 and the CCD camera 14. 14 is disposed so as to have an angle of 90 ° with respect to the optical path of the laser beam. The optical paths from the illumination lamp 13 and the CCD camera 14 are bent by 90 ° by the half mirrors 15 and 16, respectively, so as to coincide with the optical path of the laser beam.

  Further, the laser unit 2 includes a control unit for a laser beam irradiation region on the substrate 1. The laser beam emitted from the laser oscillator 10 has a predetermined beam diameter, and this laser beam irradiation area is controlled by a slit-like opening through which the laser beam passes so as to be a predetermined irradiation area with respect to this beam diameter. 21 (see FIG. 3) is variable, and the slit mechanism 12 is incorporated in the laser unit 2 for this purpose. The slit mechanism 12 is located closer to the laser unit 2 than the defect observation unit. However, the slit mechanism 12 may be disposed below the defect observation unit.

  An objective lens 17 provided with a focus controller is located at the position closest to the substrate 1 in the optical axis of the laser beam from the laser oscillator 10, and the substrate 1 can be photographed by the objective lens 17. . Accordingly, when the laser unit 2 is moved to a position where the defect portion F exists on the substrate 1, an image of the defect portion F can be put in the field of view of the CCD camera 14.

  Next, an example of a specific configuration of the slit mechanism 12 is shown in FIGS. As shown in FIG. 3, the slit mechanism 12 has four light shielding plates 20R, 20L, 20F, and 20B (reference numeral 20 is used to collectively refer to the light shielding plates). A square slit opening 21 is defined by the plate 20. The slit-shaped opening 21 becomes a laser beam irradiation region for the substrate 1. The slit-shaped opening 21 is variable, and in the direction perpendicular to the optical axis of the laser beam, the light-shielding plates 20R and 20L are moved closer to and away from each other in the direction indicated by the arrows in the figure, thereby forming a slit-shaped opening 21. The width dimension b of the opening 21 is variable, and the length dimension d of the slit-shaped opening 21 is changed by bringing the light shielding plates 20F and 20B close to and away from each other. Further, the slit-shaped opening 21 is variable not only in the width dimension b and the length dimension d but also in the opening shape. That is, the slit-like opening 21 can take not only a rectangle and a square but also a shape such as a parallelogram, a rhombus, and a trapezoid.

  As described above, in order to make the slit-shaped opening 21 variable, as shown in FIG. 4, each of the light shielding plates 20R, 20L, 20F, and 20B includes reciprocating drive means 22R, 22L, and 22F made of a motor or the like. , 22B and rotation drive means 23R, 23L, 23F, 23B. Accordingly, each of the light shielding plates 20R, 20L, 20F, and 20B can be reciprocated and rotated independently. When the wiring pattern is as shown in FIG. 1, that is, when the gate line G is straight, the light shielding plates 20F and 20B are not necessarily provided with the rotation driving means 23F and 23B.

  The present embodiment is configured as described above. Next, a method for correcting a defect of the substrate 1 will be described. Here, the substrate 1 may constitute one liquid crystal panel. However, in recent years, in order to increase production efficiency, a plurality of liquid crystal panels are cut out from a large-sized substrate. A plurality of liquid crystal panel regions are formed on one substrate. In any case, if the gate line G and the drain line D constituting the wiring pattern are energized, heat will be generated if there is a short-circuit portion. If there is a short circuit, the rough location can be specified.

  Therefore, as shown in FIG. 5, an inspection correction stage 3 having a positioning means for the substrate 1 is provided, and an infrared imaging device 4 is arranged at an upper position of the inspection correction stage 3. Here, the inspection correction stage 3 is fixedly held by vacuum suction or the like in a state where the substrate 1 conveyed by a transfer robot or the like is positioned at a predetermined position. Although not shown, a prober is brought into and out of contact with each liquid crystal panel region 1a of the substrate 1 carried into the inspection / correction stage 3, thereby energizing each liquid crystal panel region 1a. It can be done. As a result of this energization, if there is a short circuit between adjacent gate lines G, adjacent drain lines D, or between gate lines G and drain lines D at any location on the substrate 1, the location is It will generate heat. This heat generation location is detected by an infrared imaging device 4 provided at an upper position of the substrate 1.

  Since the infrared imaging device 4 puts the entire substrate 1 in the field of view, whether or not a short circuit has occurred and, if a short circuit has occurred, its rough position is detected. If there is no short-circuit location, the substrate 1 proceeds to the next step. On the other hand, when a short circuit location is detected on the substrate 1, the laser unit 2 is moved to a position facing the short circuit location F on the top of the substrate 1 to perform epi-illumination from the illumination lamp 13. By performing predetermined image processing, the exact position and shape of the defective portion F due to a short circuit are detected. Then, the light shielding plates 20R, 20L, 20F, and 20B constituting the slit mechanism 12 are moved so that the slit-shaped opening 12 is adjusted to match the shape pattern of the defective portion F. Specifically, when the shape of the defect portion F is as shown in FIG. 1, the slit mechanism 12 that partitions and forms the slit-like opening 21 is operated and projected onto the substrate 1 through the objective lens 17. The slit-shaped opening 21 to be made coincides with the defective portion F. That is, as shown in FIG. 6, the light shielding plates 20F, 20B for controlling the length direction of the slit-shaped opening 21 are moved in the arrow direction by the reciprocating drive means 22F, 22B, Match. On the other hand, the light shielding plates 20R and 20L for controlling the width direction of the slit-shaped opening 12 drive the reciprocating drive means 22R and 22L as indicated by arrows in the figure, and the light shielding plates by the rotational drive means 23R and 23L. 20R and 20L are rotated to coincide with the width direction of the defect portion F. Here, since the laser beam is irradiated onto the substrate 1 through the objective lens 17, the shape of the slit-like opening 21 is similar to that of the defect portion F, and the slit-like opening 21 has a larger dimension. Since the defect portion F in the substrate 1 is extremely small, the operation controllability of the slit mechanism 12 is better as far as possible from the objective lens 17. In the laser unit 2, the slit mechanism 12 can be disposed at a position far from the objective lens 17 by positioning the objective lens 17 between the laser oscillator 10 and the defect observation unit.

  In this state, the excess conductive film formed on the substrate 1 is removed by irradiating the laser beam from the laser oscillator 10. Accordingly, the defect is corrected by one-time irradiation with the laser beam, and the shape of the corrected portion has no irregularities and becomes a straight shape with a sharp shape. Therefore, this defect correcting portion does not interfere with the subsequent process.

It is explanatory drawing about the shape of the location which needs correction which shows one Embodiment of this invention. It is structure explanatory drawing of a laser unit. It is structure explanatory drawing of the light-shielding plate in a slit mechanism. It is explanatory drawing which shows the structure of the drive means of a light shielding plate. It is a schematic block diagram which shows the apparatus for performing defect correction. It is explanatory drawing of the operation | movement controlled so that a light shielding plate may be match | combined with a defect location.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Laser unit 3 Inspection correction stage 4 Infrared imaging device 10 Laser oscillator 12 Slit mechanism 13 Illumination lamp 14 CCD camera 20, 20R, 20L, 20F, 20B Light-shielding plate 21 Slit-shaped opening 22R, 22L, 22F, 22B Reciprocating drive Means 23R, 23L, 23F, 23B Rotation drive means

Claims (4)

It consists of a laser oscillator and a slit mechanism that controls the irradiation area of the laser beam emitted from the laser oscillator to the substrate. The laser is designed to be a variable irradiation area with respect to a predetermined pattern formed on the substrate surface. In an apparatus for correcting a pattern formed on this substrate by irradiating a beam,
The slit mechanism is composed of four light shielding plates provided in a direction perpendicular to the optical axis of the laser beam in order to form an aperture through which the laser beam passes.
Each of the light shielding plates can be reciprocated by a predetermined interval by independent reciprocating driving means, and at least two light shielding plates constituting two opposite sides are further separated by a predetermined angle on a horizontal plane by independent rotating driving means. An apparatus for correcting a defect in a substrate, wherein the apparatus is configured to be rotatable and to change a shape of the opening. 2. The defect correcting apparatus for a substrate according to claim 1, wherein a reciprocating drive means and a rotational drive means are mounted on each of the four movable light shielding plates constituting the two opposite sides. The laser oscillator and the slit mechanism are configured as a laser unit that is integrated with the imaging means and its illumination means on the surface of the substrate and a condensing optical system, and the laser unit can move on two orthogonal axes. 3. The defect correction apparatus for a substrate according to claim 1, wherein the defect correction apparatus has a structure as described above. In order to form a laser oscillator and an irradiation region of the laser beam emitted from this laser oscillator, a film is formed on the surface of the substrate by irradiating the laser beam through a slit mechanism having four movable light shielding plates. A method for correcting a defect of a predetermined pattern formed by:
By adjusting the position of each movable light-shielding plate of the slit mechanism in the horizontal direction and the rotation direction, the opening formed by the slit mechanism is made to coincide with the defective portion in the pattern on the substrate surface,
A pattern correction method comprising: irradiating a laser beam from the laser oscillator toward the substrate through the opening to remove an excessive film member at the defective portion .

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