JP2008021451A - Defect correction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a defect correction method capable of correcting a recess defect in a narrow flat part. <P>SOLUTION: In the defect correction method, a repair paste 20 is coated on the recess defect 42a of a dielectric layer 42 and dried, then, the dried repair paste 20A is worked to a height h obtained in advance, and the worked repair paste 20A is calcined and made to shrink, and the surface of the repair paste 20B is aligned to the surface of the dielectric layer 42. Thereby, since the soft repair paste 20A before calcining is worked, it can be worked by a rotating tool of small diameter with low peripheral speed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a defect correction method, and more particularly to a defect correction method for correcting a concave defect on a substrate surface. More specifically, the present invention relates to a defect correction method in which a correction paste is applied to a concave defect generated on a glass substrate surface or a flat surface portion of a dielectric layer in a flat panel display or the like to correct the defect.

  FIG. 3 is an exploded view showing the structure of a plasma display panel (PDP). In FIG. 3, the plasma display panel includes a front glass substrate 30 and a back glass substrate 40. On the back surface of the front glass substrate 30, a plurality of composite electrodes each having a wide width transparent electrode 31 and a narrow width bus electrode 32 are formed at a predetermined pitch, and these are covered with a dielectric layer 33 and a protective film 34. Has been. A plurality of address electrodes 41 are formed on the surface of the back substrate 40 at a predetermined pitch, and these are covered with a dielectric layer 42. A plurality of ribs (partition walls) 43 are formed on the surface of the dielectric layer 42 at a predetermined pitch, and each valley is covered with an R, G, or B phosphor layer 44.

  The front glass substrate 30 and the rear glass substrate 40 are fixed via the ribs 43 so that the bus electrodes 32 and the address electrodes 41 are orthogonal to each other. As a result, a discharge space called a cell is formed at each intersection of the bus electrode 32 and the address electrode 41. When a voltage is selectively applied to the plurality of bus electrodes 32 and the plurality of address electrodes 41, each cell selectively discharges and emits light, and one image is displayed on the plasma display panel.

  Although the plasma display panel having the straight straight ribs 43 has been described with reference to FIG. 3, plasma display panels having various shaped ribs such as rectangular waffle ribs and hexagonal meander ribs have been developed. Yes.

  By the way, in the manufacturing process of such a plasma display panel, a minute concave defect may occur in a part of the planar portion of the dielectric layers 33 and 42. If there is such a concave defect, the spatial volume of the cell changes, the discharge state becomes abnormal, and the quality of the image is degraded and the address electrode 41 and the like are degraded. For this reason, when the rib 43 is formed on the dielectric layer 33 on the front glass substrate 30 side or the dielectric layer 42 on the rear glass substrate 40 side, the dielectric layer 42 at the bottom of the portion surrounded by the ribs 43 is formed. There is a need to correct the resulting concave defects.

As a method for correcting a concave defect generated in such a vitreous portion, for example, Patent Document 1 discloses a method for correcting a rib chip defect in which a part of a rib is cut. In this defect correction method, a material that precipitates glass locally is applied to a rib chip defect, fired by irradiating a laser beam, and a protrusion generated after firing is removed using a diamond blade.
JP 2000-82405 A

  However, the bottom surrounded by the ribs 43 is as small as about 200 × 400 μm, and a diamond blade cannot be inserted, so that the protrusions generated after firing cannot be removed. If a small diameter tool that can be inserted into the bottom surrounded by the ribs 43 is used, the circumferential speed and the rigidity of the quill are insufficient, and the protrusion cannot be removed.

  Therefore, a main object of the present invention is to provide a defect correcting method capable of correcting a concave defect in a narrow flat portion.

  The defect correction method according to the present invention is a defect correction method for correcting a concave defect on a substrate surface, wherein a first correction paste is applied to the concave defect and dried to form a dry paste portion higher than the substrate surface. And a second step of processing the dry paste portion so that the height of the dry paste portion viewed from the substrate surface is a value determined in advance in consideration of a shrinkage amount when the dry paste portion is baked, And a third step of firing the dry paste portion and aligning the surface of the fired portion with the substrate surface.

  Preferably, in the second step, the height shape of the dry paste portion is measured using a non-contact displacement meter on the basis of the substrate surface, and the dry paste portion is processed based on the measurement result.

  Preferably, in the second step, the dry paste portion is processed using a rotary tool such as a rotary grindstone or an end mill.

Preferably, in the third step, the dry paste portion is fired by irradiation with CO ₂ laser light.

  In the defect correction method according to the present invention, the correction paste is applied to the concave defect and dried to form a dry paste portion higher than the substrate surface, and the height of the dry paste portion viewed from the substrate surface The dry paste part is processed so as to have a value obtained in advance in consideration of the shrinkage amount when fired, and the dry paste part is fired to align the surface of the fired part with the substrate surface. Therefore, since the correction paste is not processed after firing, but is processed in a state where the correction paste is dried, even a tool having a small diameter can be processed. Therefore, it is possible to correct a concave defect generated in a narrow flat portion where a large-diameter tool cannot be used.

  FIG. 1A is an external view showing the overall configuration of a defect correcting apparatus according to an embodiment of the present invention, and FIG. 1B is an enlarged view of a portion A in FIG. 1 (a) and 1 (b), this defect correcting apparatus is such that a rear glass substrate 40 for a plasma display panel to be corrected is placed on the surface thereof and parallel to the rear glass substrate 40 in the Y-axis direction in the figure. The Y-axis table 1 that moves, the Z-axis table 2 that moves in the Z-axis direction in the drawing perpendicular to the rear glass substrate 40, and the Z-axis table 2 mounted thereon are parallel to the rear glass substrate 40 and perpendicular to the Y-axis. And an X-axis table 3 that moves in the X-axis direction in the figure.

On the Z-axis table 2, an observation optical system 4 for observing a concave defect of the dielectric layer 42 formed on the surface of the back glass substrate 40, and a correction paste application for applying a correction paste to the concave defect using a needle A mechanism 5, a continuous wave laser device 6 that irradiates the applied correction paste with laser light to dry or fire it, a pulsed laser device 7 that cuts excess correction paste that protrudes from the concave defect, and an excess cut The scratch mechanism 8 that removes the correction paste by needle or vacuum suction, the spindle 9 that polishes the dried correction paste with a grindstone, and sets the height to a predetermined value, and the surface of the dielectric layer 42 as a reference. A displacement meter 10 is provided for measuring the height shape of the dried paste portion in a non-contact manner. As the continuous wave laser device 6, a CO ₂ laser having a long laser beam wavelength and a large thermal effect is used. The Z-axis table 2 is driven by a Z-axis drive motor 11.

  The observation optical system 4 includes a microscope including a plurality of objective lenses and a revolver that selects any one of them, and a CCD camera. The correction paste application mechanism 5 includes an application needle, an actuator that drives the application needle up and down, a tank of correction paste, and the like. The observation optical system 4, the correction paste application mechanism 5, the laser devices 6 and 7, the scratch mechanism 8, the spindle 9, and the displacement meter 10 constitute a correction head.

  The Z-axis table 2 adjusts the focus of the observation optical system 4 by positioning the substrate 40 and the correction head relative to each other in the Z direction perpendicular to the rear glass substrate 40, or adjusts the Z-axis direction of the correction paste application mechanism 5 in the Z-axis direction. It is used for positioning and bringing the needle of the scratch mechanism 8 and the grindstone of the spindle 9 into contact with the substrate 40. The X-axis table 3 and the Y-axis table 1 are used for relative positioning of the substrate 40 and the correction head in an XY plane parallel to the rear glass substrate 40. Each of the X-axis table 3, the Y-axis table 1, and the Z-axis table 2 is driven by a motor, a ball screw, or the like. The configuration of the positioning mechanism is not limited to the tables 1 to 3, and any configuration may be used as long as the relative position of the substrate 40 and the correction head can be adjusted in the X, Y, and Z directions.

  In addition, the defect correction apparatus includes a control unit 12 that controls the entire defect correction apparatus, and an operation unit 13 that serves as a user interface. The control unit 12 sends a control signal to the entire defect correction apparatus based on a command signal from the operation unit 13. The operation unit 13 includes a display device for images taken by a CCD camera, a coordinate input device, an instruction device for various operations, and the like.

  Next, a method for correcting the concave defect of the dielectric layer 42 using this defect correction apparatus will be described. First, the rear glass substrate 40 on which the dielectric layer 42 is formed is placed on the Y-axis table 1, the Y-axis table 1 and the X-axis table 3 are moved in the horizontal direction, and the concave defect is caused by the correction paste application mechanism 5. Position it so that it is directly below. As the correction paste application mechanism 5, for example, a mechanism as shown in FIG. 8 of JP-A-9-265007 is used. As shown in FIG. 2A, the correction paste 20 is applied to the concave defect 42a by the application needle of the paste application mechanism 5. At this time, the correction paste 20 is swelled on the concave defect 42a and is applied so as to be higher than the flat portion around the concave defect 42a.

Next, the Y-axis table 1 and the X-axis table 3 are moved in the horizontal direction and positioned so that the concave defect 42a comes directly below the continuous wave laser device 6. Next, as shown in FIG. 2A, the correction paste 20 applied to the concave defect 42a is irradiated with CO ₂ laser light α, and the correction paste 20 is heated and dried. In this state, the applied correction paste 20 is only hardened with no moisture.

  Next, the Y-axis table 1 and the X-axis table 3 are moved in the horizontal direction and positioned so that the concave defect 42a comes below the displacement meter 10. The displacement meter 10 measures the height shape of the dried correction paste 20A in a non-contact manner with reference to the surface of the dielectric layer 42 around the concave defect 42a. This measurement result is stored in the control unit 12.

  Next, the Y-axis table 1 and the X-axis table 3 are moved in the horizontal direction, and positioned so that the concave defect 42 a comes below the spindle 9. The control unit 12 controls the tables 1 to 3 and the spindle 9 based on the measurement result of the displacement meter 10, and as shown in FIG. 2B, the correction paste 20 </ b> A dried by the rotating grindstone 21 at the lower end of the spindle 9. Process. At this time, the correction paste 20A has not yet been fired and is soft, so that it can be easily polished and removed by the small-diameter rotating grindstone 21 having a diameter of 0.2 mm or less. An end mill may be used instead of the rotating grindstone 21.

  Further, the height h of the dried corrected paste 20A is set to a value obtained in advance in consideration of the shrinkage amount of the corrected paste 20A during firing. The amount of shrinkage at the time of firing varies depending on the components of the correction paste 20, and the same correction paste 20 is applied and fired in advance, and the amount of shrinkage is obtained by a preliminary test.

Next, the Y-axis table 1 and the X-axis table 3 are moved in the horizontal direction and positioned so that the concave defect 42a comes directly below the continuous wave laser device 6. Next, as shown in FIG. 2C, the correction paste 20A applied to the concave defect 42a and dried is irradiated with CO ₂ laser light β stronger than the laser light α of FIG. 2a), and the correction paste 20A and its surroundings are irradiated. The dielectric layer 42 is heated to a temperature at which both of the dielectric layers 42 are melted and fired. In addition, when the concave defect 42a is long, baking is performed while relatively moving the light spot of the laser beam β along the correction paste 20A. The power of the laser beam β and the moving speed of the light spot may be tested in advance and set to optimum values. Then leave it to solidify with the surroundings and finish the correction. The surface of the corrected paste 20B after firing is substantially the same as the surface of the dielectric layer 42.

  In this embodiment, the correction paste 20 is applied to the concave defect 42a of the dielectric layer 42 and dried, the dried correction paste 20A is processed to a predetermined height h, and the processed correction paste 20A is baked and contracted. The surface of the correction paste 20B is aligned with the surface of the dielectric layer 42. Therefore, the correction paste 20A processed with the tool is soft before firing, so it can be processed even with a small diameter rotating tool with a low peripheral speed, and even if the tool has a small diameter, the load is small and the tool life is extended. Can be achieved. Further, it can be processed by a small-diameter rotating grindstone 21 or an end mill having a diameter of 0.4 mm or less, and the concave defect 42 a generated at the narrow bottom between the ribs 43 can be corrected.

  Further, since the non-contact type displacement meter 10 is used, the upper surface shape of the dry soft correction paste 20A and the displacement of the surrounding plane can be measured at the same time, and the height of the correction paste 20A can be measured based on the measurement result. H can be indicated. Therefore, the dried corrected paste 20A can be processed to an accurate height h.

  Further, the shrinkage amount of the correction paste 20A at the time of firing is investigated in advance, the correction paste 20A is accurately processed so that the height h of the dried correction paste 40A becomes the shrinkage amount, and the correction paste 20A and the surroundings Since the dielectric layer 42 is melted together and solidified, the surrounding dielectric layer 42 and the correction paste 20A are mixed, and a smooth and good correction surface can be obtained.

  When firing by irradiating with laser light β, the firing condition is observed with a CCD camera obliquely from above, thereby adjusting the power of laser light β, the size of the light spot, the moving speed of the light spot, etc. Good.

  Further, when the applied correction paste 20 is dried, a halogen lamp light or the like may be irradiated instead of the laser light α.

  In this embodiment, the case where the concave defect 42a of the dielectric layer 42 on the surface of the rear glass substrate 40 of the plasma display panel is corrected has been described. However, the present invention is not limited to this. Needless to say, the present invention can also be applied to the correction of concave defects generated in the above.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows the structure of the defect correction apparatus by one Embodiment of this invention. It is a figure which shows the defect correction method using the defect correction apparatus shown in FIG. It is an assembly exploded view which shows the structure of the plasma display panel which is a correction object.

Explanation of symbols

  1 Y-axis table, 2 Z-axis table, 3 X-axis table, 4 observation optical system, 5 correction paste application mechanism, 6 continuous wave laser device, 7 pulse oscillation laser device, 8 scratch mechanism, 9 spindle, 10 displacement meter, 11 Z-axis drive motor, 12 control unit, 13 operation unit, 20, 20A, 20B correction paste, 21 rotating grindstone, 30 front glass substrate, 31 transparent electrode, 32 bus electrode, 33, 42 dielectric layer, 44 protective film, 40 Rear glass substrate, 41 address electrode, 43 rib, 44 phosphor layer.

Claims (4)

A defect correction method for correcting a concave defect on a substrate surface,
A first step of applying a correction paste to the concave defect and drying to form a dry paste portion higher than the substrate surface;
A second step of processing the dry paste portion so that the height of the dry paste portion viewed from the substrate surface is a value determined in advance in consideration of a shrinkage amount when the dry paste portion is baked; ,
And a third step of firing the dry paste portion and aligning the surface of the fired portion with the substrate surface.   In the second step, the height shape of the dry paste portion is measured with reference to the substrate surface using a non-contact displacement meter, and the dry paste portion is processed based on the measurement result. The defect correction method according to claim 1.   The defect correction method according to claim 1, wherein in the second step, the dry paste portion is processed using a rotary tool such as a rotary grindstone or an end mill. 4. The defect correcting method according to claim 1, wherein in the third step, the dry paste portion is fired by irradiating a CO ₂ laser beam. 5.

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