JP2011013413A - Method for manufacturing plasma display panel, and photomask used for the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress generation of defects such as disconnection in a PDP pattern due to dust or the like depositing on a photomask in an exposure step, and to obtain a uniform pattern width even in a large screen with high definition.SOLUTION: A method for manufacturing a PDP is provided for manufacturing a plurality of PDPs having a structure on at least one substrate, and the method includes a first exposure step and a second exposure step for forming the structure, and a step of measuring a shift amount between the exposure position in the first exposure step and the exposure position in the second exposure step. An exposure position in the first exposure step or in the second exposure step upon manufacturing the subsequent plasma display panels is corrected on the basis of the measured shift amount.

Description

  The present invention relates to a liquid crystal display panel (hereinafter referred to as LCD) and a plasma display panel (hereinafter referred to as PDP).

  The PDP generates an ultraviolet ray by gas discharge and performs image display by exciting a phosphor with the ultraviolet ray to emit light.

  PDPs can be broadly classified into AC and DC types as drive systems, and surface discharge types and counter discharge types as discharge types, but they are easy to manufacture due to high definition, large screen, and simple structure. Therefore, at present, a surface discharge type PDP having a three-electrode structure is mainly used. The structure is orthogonal to the display electrode on a substrate such as glass, having a display electrode composed of a scan electrode and a sustain electrode, a dielectric layer covering the display electrode, and a protective layer covering the display electrode. By disposing a plurality of address electrodes, a dielectric layer covering the address electrodes, and a back plate having a partition on the dielectric layer, a discharge cell is formed at the intersection of the display electrode and the address electrode, In addition, a phosphor layer is provided in the discharge cell.

  In this configuration, since the display electrode and the address electrode are required to have high accuracy in shape and arrangement pitch, for example, a material containing a photosensitive material in a conductive material such as a metal material is used. By coating and drying the entire surface of the substrate, exposing it to a photomask having an exposure pattern for exposing it to an electrode pattern, and then developing it, patterning is performed by a so-called photolithography method, so that a predetermined position is predetermined. A shaped electrode is formed.

  In the photolithography method, when a negative material is used as the photosensitive material, if dust or the like adheres to the exposed portion of the exposure pattern provided in the photomask, the photosensitive material corresponding to the exposed portion is polymerized without being exposed to light. Disappear. In this case, the portion is dissolved at the time of development, resulting in “missing”, leading to chipping / disconnection of the display electrode and the address electrode. Here, if a disconnection occurs, power cannot be supplied to the pixels downstream in the power feeding direction from the disconnection occurrence point, which causes a problem in image display in the PDP and becomes a fatal defect.

  Therefore, in order to suppress the occurrence of the disconnection as described above, there is a method of performing exposure a plurality of times using a plurality of photomasks having the same exposure pattern. As a result, even if a chipped or disconnected portion is generated due to dust adhering to one photomask, it is possible to compensate for the disconnection by exposing the portion by exposure using the other photomask (for example, , See Patent Document 1).

  In the above technique, there is a method of performing exposure a plurality of times using a plurality of photomasks having different exposure pattern widths. This is to suppress the occurrence of defects such as disconnection in the PDP structure, and to suppress the warping and peeling of the structure (for example, Patent Documents 2 and 3). reference).

JP 2005-250465 A JP-A-1-281448 JP 2004-342348 A

  By the way, in a thin display device typified by an LCD or a PDP, a display screen is becoming larger. For this reason, in the manufacturing process of a thin display device, a plurality of patterns are formed on a single large substrate at a time so that a plurality of patterns can be obtained by a single process, and cleaved into a single plate after the pattern is completed. The cost is reduced by reducing man-hours.

  On the other hand, the demand for high-definition displays is increasing in response to digital terrestrial television broadcasting, and the pixel pitch is reduced and the structure pattern is becoming thinner.

  For this reason, high accuracy is also required in the exposure process for forming the display electrode pattern. However, if the exposure is performed a plurality of times as described above, the transfer position is likely to be shifted in each exposure process.

  In the prior art, in consideration of such transfer deviation, for example, a method of performing exposure twice using a photomask having a main pattern and a photomask having a sub-pattern thinner than the main pattern for disconnection compensation is adopted. ing.

  However, with the increase in size of the substrate and photomask and the increase in definition of the display electrodes, the amount of misalignment that occurs in each exposure process tends to increase. The disconnection compensation sub-pattern is originally designed to be thinner than the main pattern by a predetermined amount so as to be hidden by the main pattern. However, if the transfer position deviation exceeds the allowable amount, the sub-pattern protrudes from the main pattern to obtain a predetermined pattern width. I can't do that.

  The present invention has been made in view of these problems, and provides a PDP having a uniform pattern width even when the display electrode pattern of the PDP is free from defects such as disconnection and has a large screen and high definition. With the goal.

  In order to solve the above-described problem, a PDP manufacturing method of the present invention is a PDP manufacturing method for manufacturing a plurality of PDPs having a structure on at least one substrate. A step and a second exposure step, and a step of measuring a deviation amount between the exposure position in the first exposure step and the exposure position in the second exposure step. The exposure position of the exposure step or the second exposure step is corrected.

  Further, there are different locations in the first exposure pattern exposed in the first exposure step and the second exposure pattern exposed in the second exposure step, and it is desirable to measure the shift amount from the location of the different locations. The structure is an electrode used for the discharge of the PDP, and it is preferable that the first exposure step and the second exposure step are performed in order to compensate for disconnection of the electrode.

  The photomask of the present invention is used for the first exposure step and the second exposure step.

  With the PDP and photomask of this configuration, the transfer position of the main pattern, which is the first exposure step, and the transfer position of the sub pattern, which is the second exposure step, can be recognized independently. Can be confirmed.

  According to the PDP of the present invention, by correcting the transfer position of the main pattern and the transfer position of the sub pattern relatively, it is possible to suppress the occurrence of defects such as disconnection in the PDP pattern due to dust or the like adhering to the photomask. In addition, a uniform pattern width can be obtained even with a large screen and high definition.

Sectional perspective view which shows an example of schematic structure of PDP by embodiment of this invention The figure which shows the general | schematic flow of the process of forming the address electrode in the manufacturing method of the PDP. The top view which shows typically the opening pattern of the 1st photomask and 2nd photomask in the manufacturing method of the PDP Diagram showing misalignment The figure which shows the example of the reference | standard position mark and position confirmation mark of this invention

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(Embodiment)
First, an example of the structure of the PDP will be described. FIG. 1 is a cross-sectional perspective view showing an example of a schematic configuration of a PDP manufactured by a method for manufacturing a PDP according to an embodiment of the present invention.

  The front plate 2 of the PDP 1 is provided between a display electrode 6 formed of a scanning electrode 4 and a sustain electrode 5 on one main surface of a smooth, transparent and insulating front substrate 3 and between adjacent display electrodes 6. The structure includes a light shielding layer 7, a dielectric layer 8 that covers the display electrode 6 and the light shielding layer 7, and a protective layer 9 made of, for example, MgO that covers the dielectric layer 8. Scan electrode 4 and sustain electrode 5 have a structure in which a bus electrode made of a highly conductive material such as a metal material is laminated on a transparent electrode for the purpose of reducing electric resistance.

  The back plate 10 includes an address electrode 12 formed on one main surface of a smooth and insulating back substrate 11, a dielectric layer 13 covering the address electrode 12, and adjacent address electrodes on the dielectric layer 13. 12 is a structure having a partition wall 14 located at a location corresponding to 12 and phosphor layers 15R, 15G, and 15B between the partition walls 14.

  The front plate 2 and the back plate 10 are configured such that the display electrodes 6 and the address electrodes 12 face each other with the partition wall 14 therebetween, and the periphery is sealed with a sealing member. For example, a mixed gas of neon and xenon is sealed in the discharge space 16 formed between the back plate 10 and the back plate 10 as a discharge gas. The intersection between the display electrode 6 and the address electrode 12 in the discharge space 16 operates as a discharge cell (unit light emitting region).

  Next, a manufacturing method of the PDP 1 having the above-described structure will be described with reference to FIG. The front plate 2 first forms the scan electrodes 4 and the sustain electrodes 5 on the front substrate 3 in a stripe shape, for example.

Specifically, a transparent electrode material, for example, a film made of ITO, for example, is formed on the front substrate 3 by, for example, an electron beam evaporation method, and a resist is patterned thereon so as to remain as a transparent electrode pattern. Then, the film | membrane by the material of a transparent electrode is etched by an etching, and a transparent electrode is formed by peeling a resist after that. In addition, SnO ₂ etc. can also be used as a transparent electrode material.

Then, a bus electrode is formed on the transparent electrode formed as described above. Specifically, a black pigment, glass frit (PbO—B ₂ O ₃ —SiO ₂ system, Bi ₂ O ₃ —B ₂ O ₃ —SiO ₂ system, etc.), a polymerization initiator, a photocurable monomer, and an organic solvent are used. A conductive material containing Ag as a material on a black electrode film by a screen printing method or the like after forming a black electrode film on a glass substrate by a screen printing method or the like using a photosensitive black paste containing , Photosensitive frit containing glass frit (PbO—B ₂ O ₃ —SiO ₂ system, Bi ₂ O ₃ —B ₂ O ₃ —SiO ₂ system, etc.), polymerization initiator, photocurable monomer, organic solvent A metal electrode film is formed and dried again.

  Then, the bus electrode can be formed by patterning and baking by photolithography. As described above, the display electrode 6 including the scan electrode 4 and the sustain electrode 5 can be formed.

  Next, the light shielding layer 7 is formed. This can be formed by forming a photosensitive black paste into a film by a screen printing method or the like, then patterning and baking it by a photolithography method. The light shielding layer 7 may be formed simultaneously with the base black layer of the bus electrode. Moreover, if it is black, it does not need to be a formation method using a paste. Further, it may be formed before the bus electrode is formed.

  Next, the display electrode 6 and the light shielding layer 7 formed as described above are covered with a dielectric layer 8. The dielectric layer 8 is formed by applying a paste containing a lead-based glass material by, for example, screen printing, drying, and then baking.

  Next, the dielectric layer 8 is covered with a protective layer 9. The protective layer 9 is made of, for example, MgO and is formed by a film forming process such as vapor deposition or sputtering.

  On the other hand, the back plate 10 has address electrodes 12 formed on a back substrate 11 in a stripe shape, for example. Specifically, a material is formed on the substrate 11 by using a material of the address electrode 12, for example, a photosensitive Ag paste, and a film is formed by a screen printing method or the like, followed by patterning and baking by a photolithography method or the like. be able to.

  Next, the address electrode 12 formed as described above is covered with a dielectric layer 13. The dielectric layer 13 is formed by, for example, applying and drying a paste containing a lead-based glass material by screen printing, for example, and then baking the paste. Further, instead of screen-printing the paste, it may be formed by laminating and firing a precursor of a molded film-like dielectric layer.

Next, the partition walls 14 are formed in a lattice shape, for example. The partition wall 14 can be formed by forming a photosensitive paste mainly composed of an aggregate such as Al ₂ O ₃ and glass frit by a printing method or a die coating method, patterning by a photolithography method, and baking. it can. Alternatively, for example, a paste containing a lead-based glass material may be formed by, for example, repeatedly applying and drying at a predetermined pitch by a screen printing method and then baking.

  And in the groove | channel between the partition 14 and the partition 14, fluorescent substance layer 15R, 15G, 15B comprised by each fluorescent substance particle of red (R), green (G), and blue (B) is formed. This is done by applying and drying a paste-like phosphor ink composed of phosphor particles of each color and an organic binder, and baking it at a temperature of 400 ° C. to 590 ° C. to burn off the organic binder. The phosphor layers 15R, 15G, and 15B are formed by binding particles.

The front plate 2 and the back plate 10 produced as described above are overlapped so that the display electrodes 6 of the front plate 2 and the address electrodes 12 of the back plate 10 are orthogonal to each other, and a sealing member such as sealing glass is provided on the periphery. This is sealed with an airtight seal layer (not shown) formed by firing at about 450 ° C. for 10 to 20 minutes, for example. Then, once the inside of the discharge space 16 is evacuated to a high vacuum (for example, 1.1 × 10 ⁻⁴ Pa), a discharge gas (for example, a He—Xe-based inert gas) is encapsulated to manufacture the PDP 1. To do.

  As described above, since the PDP 1 has a large screen, the PDP 1 structure such as the display electrode 6, the light shielding layer 7, the address electrode 12, and the partition wall 14 requires accuracy with respect to the shape and position. As a method for forming the structure, a photolithography method is often used.

  Therefore, in the photolithography method in the manufacturing method of the PDP 1 according to the present invention, the address electrode 12 is taken as an example of the structure of the PDP, and the formation process is centered on the flow of the exposure process, which is a characteristic point of the present invention. Next, it demonstrates using a figure.

  FIG. 2 is a diagram showing a schematic flow of steps in forming the address electrode 12. Further, as will be described later, the process of forming the address electrode 12 includes a first exposure step and a second exposure step, and a first photomask and a second photomask having different patterns in each process. Use. FIG. 3 is a partially enlarged plan view for schematically showing the relative relationship between the opening patterns of the first photomask and the second photomask. FIG. 3A shows the first photomask, and FIG. ) Indicates a second photomask.

  First, as shown in FIG. 2 (a), a photosensitive Ag paste having an Ag material as a material of the address electrode 12 is used, and this is uniformly applied to the back substrate 11 by a screen printing method or the like. An Ag paste film 21 is formed.

  Next, as shown in FIG.2 (b), the 1st photomask 22 provided with the opening part 22a is aligned and installed in a predetermined position. Here, as shown in FIG. 3, the opening width W1 of the opening 22a in the first photomask 22 takes into account the blurring of the transfer pattern due to the collimation half angle and the declination angle, and the pattern width of the address electrode 12 is set to a desired pattern. The correction value α is added and corrected so that the width W can be formed. That is, W = W1 + α.

  In this state, as shown in FIG. 2C, a first exposure step is performed on the photosensitive Ag paste film 21. Specifically, the ultraviolet ray 23 is irradiated by an ultra high pressure mercury lamp. By this exposure, as shown in FIG. 2C, the main pattern 31 of the pattern of the address electrode 12 is exposed.

  Next, as shown in FIG.2 (d), the 2nd photomask 24 provided with the opening part 24a is aligned and installed in a predetermined position. Here, as shown in FIG. 3, the opening width W <b> 2 of the opening 24 a in the second photomask 24 is the same as that of the first photomask 22 and the second width W1 of the opening 22 a in the first photomask 22. The photomask 24 is formed small in consideration of the transfer position error Dt.

  Then, in this state, as shown in FIG. 2E, the second exposure step is performed on the photosensitive Ag paste film 21 by irradiating the ultraviolet ray 23 from the ultrahigh pressure mercury lamp. By this exposure, as shown in FIG. 2E, the sub-pattern 32 of the address electrode 12 is exposed while being overlapped with the main pattern 31 in the first exposure step.

  Then, the photosensitive Ag paste film 21 exposed to the pattern of the address electrode 12 is developed as described above, whereby the photosensitive Ag paste film 21 can be formed into the pattern of the address electrode 12. The address electrode 12 is patterned by baking.

  Here, even if dust adheres to the first photomask 22 and the second photomask 24, the probability that the relative positions with respect to the photosensitive Ag paste film 21 match is very small. Specifically, when about 100 circular foreign matters having a diameter of 100 μm adhere on a photomask used for manufacturing a 40-inch class PDP, the positions of the foreign matters attached by the first photomask and the second photomask. The probability of matching is about 0.1% or less. In other words, when exposure is performed every time the photomask is replaced, the probability that dust is located at the same position even if the photomask is replaced with respect to the photosensitive Ag paste film 21 is very small. If the exposure is performed at each exchange, it is possible to greatly suppress the region where the exposure is blocked by the dust adhering to the photomask and is unexposed and disconnected.

  Therefore, the double exposure region in which the main pattern 31 by the first exposure and the sub pattern 32 by the second exposure formed in the pattern by the double exposure as described above overlap the photomask. Since the probability of being exposed once is very high regardless of the adhesion of dust, the pattern of the address electrode 12 has a very high probability of being disconnected due to the presence of the above-described double exposure region. Get smaller.

  Here, a shift between the main pattern 31 and the sub pattern 32 of the address electrode 12 will be described. FIG. 4 is a diagram schematically showing a positional deviation between the main pattern 31 transferred by the first photomask 22 and the sub pattern 32 transferred by the second photomask 24.

  As described above, the main pattern 31 transferred by the first photomask 22 and the subpattern 32 transferred by the second photomask 24 shown in FIG. 3 are exposed by the first exposure step and the second exposure step. A positional deviation amount Dt of the region to be generated occurs. The positional deviation amount Dt is caused by the dimensional accuracy of the first photomask 22 and the second photomask 24, or the average deviation component Ds caused by temperature variation in the manufacturing process, and the alignment error of each photomask. Variation component D1 (due to displacement of the first photomask) and D2 (due to displacement of the second photomask). That is, Dt = Ds + D1 + D2.

  Conventionally, Dt is unclear, resulting in the mass production of PDPs with poor line width. On the other hand, in the embodiment of the present invention, the opening width W2 of the opening 24a of the second photomask 24 is first set to the opening of the first photomask 22 in order to suppress the deterioration of the pattern width accuracy due to the positional deviation amount Dt. It is designed to be smaller by Dt than the opening width W1 of the portion 22a. That is, W1 = W2 + 2Dt.

  Here, the measurement of the amount of deviation will be described. FIG. 5 is a diagram showing the reference position mark 41a and the position confirmation mark 42a and their respective transfer patterns. A reference position mark 41 a is arranged on the first photomask 22, a position confirmation mark 42 a is arranged on the second photomask 24, and a main pattern transferred by the first photomask 22 and a sub transferred by the second photomask 24. Measure pattern misalignment multiple times.

  The reference position mark 41a shown in FIG. 5 (a) and the position confirmation mark 42a shown in FIG. 5 (b) are transferred to the address electrode layer formed on the back substrate 11 shown in FIG. 5 (c), respectively. 41b and the transfer pattern 42b are arranged so that they are in close proximity or overlap each other so that they can be confirmed in the same field of view of the positional deviation measuring device.

  In addition, the reference position mark 41a arranged on the first photomask 22 and the position confirmation mark 42a arranged on the second photomask 24 are arranged at the outer edge portions of the respective photomasks in order to avoid obstructing the pattern formation of the address electrodes. A plurality of, at least two or more are provided.

  The position of the center of gravity of the main pattern by the first photomask 22 derived from the transfer pattern 41b transferred with the plurality of reference position marks 41a and the second photo derived from the transfer pattern 42b transferred with the plurality of position confirmation marks 42a. By comparing the position of the center of gravity of the sub-pattern with the mask 24, it is possible to measure the average positional deviation amount Ds between the transfer pattern 42b of the reference position mark 42a and the transfer pattern 42b of the position confirmation mark 42a.

  In the present embodiment, four reference position marks 41a and four position confirmation marks 42a are provided on the outer edge of each photomask.

  The main pattern 31 and the sub-pattern 32 are offset by offsetting the position of the second photomask 24 in the second exposure step of the PDP 1 to be manufactured subsequently using the position shift amount Ds calculated by the measurement method described above. Can be corrected.

  According to this method, the positional deviation amount Ds of the product after feedback approaches zero as much as possible, the positional deviation amount Dt is reduced to Dt≈D1 + D2, the opening width W2 of the photomask can be widened by Ds, and the disconnection compensation effect Also goes up.

  In the above description, the address electrode 12 is described as an example of the PDP structure. However, the display electrode 6, the light shielding layer 7, the address electrode 12, the partition wall 14 and the like are formed on the PDP 1 structure formed by photolithography. However, the same effect can be obtained.

  As described above, the PDP according to the present invention corrects the transfer position of the main pattern and the transfer position of the sub pattern, thereby suppressing the occurrence of defects such as disconnection in the PDP pattern due to dust or the like adhering to the photomask. In addition, since a uniform pattern width can be obtained even on a large screen and high definition, it is useful as a PDP.

1 PDP
2 Front plate 3 Front substrate 4 Scan electrode 5 Sustain electrode 6 Display electrode 7 Light shielding layer 8 Dielectric layer 9 Protective layer 10 Back plate 11 Back substrate 12 Address electrode 13 Dielectric layer 14 Partition 15R, 15G, 15B Phosphor layer 16 Discharge Space 21 Photosensitive Ag paste film 22 First photomask 22a Opening 23 UV light 24 Second photomask 24a Opening 31 Main pattern 32 Subpattern 41a Reference position mark 41b Transfer pattern 42a Position check mark 42b Transfer pattern

Claims (4)

A plasma display panel manufacturing method for manufacturing a plurality of plasma display panels having a structure on at least one substrate,
The formation of the structure has a first exposure step and a second exposure step,
Measuring the amount of deviation between the exposure position in the first exposure step and the exposure position in the second exposure step;
A method for manufacturing a plasma display panel, comprising: correcting an exposure position in the first exposure step or the second exposure step in the subsequent manufacturing of the plasma display panel from the shift amount. There are different locations in the first exposure pattern exposed in the first exposure step and the second exposure pattern exposed in the second exposure step, and the shift amount is measured from the position of the different location. The plasma display panel according to claim 1, wherein: The structure is an electrode used for discharging the plasma display panel,
The plasma display panel according to claim 1, wherein the first exposure step and the second exposure step are performed to compensate for disconnection of the electrode. A photomask used for the first exposure step and the second exposure step.

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