JP2009146682A - Manufacturing method for plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain upward warpage and peeling-off of a display member; and to prevent poor exposure caused by dust stuck on a photomask, upon patterning the display member such as an electrode and a barrier of a PDP by a photolithography method. <P>SOLUTION: In a manufacturing method for a PDP including a film-making step of film-making a light-sensitive Ag paste film 41 as a display member and an exposure step of exposing the light-sensitive Ag paste film 41 through a photomask 42 having an opening 43. The exposure step includes a first exposure step of exposing the light-sensitive Ag paste film 41 and the photomask 42 by preparing an exposure gap G1, and a second exposure step of exposing by making the photomask 42 move along the opening 43 rather than the position in the first exposure step. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a plasma display panel used in a display device or the like, and more particularly to a method for manufacturing a plasma display panel in which a pattern of a display member including an electrode group is formed by a photolithography method.

  A plasma display panel (hereinafter referred to as “PDP”) has a structure in which peripheral portions of a front panel and a back panel arranged opposite to each other are sealed with a sealing material, and a discharge space formed between the front panel and the back panel. Is filled with a discharge gas such as neon and xenon.

  The front panel includes a plurality of display electrode pairs formed of scan electrodes and sustain electrodes formed in a stripe shape on one surface of a glass substrate, a light shielding layer provided between adjacent display electrode pairs, and these display electrode pairs. It comprises a dielectric layer that covers the light shielding layer and functions as a capacitor, and a protective layer made of magnesium oxide (MgO) formed on the dielectric layer. Each of the display electrode pairs includes a transparent electrode and a bus electrode made of a conductive material formed on the transparent electrode.

  The back panel has a plurality of address electrodes formed in a stripe shape in a direction perpendicular to the display electrode pair on one side of the other glass substrate, a base dielectric layer covering these address electrodes, and an address electrode for discharging space. Stripe-shaped partition walls that are partitioned every time, and phosphor layers that emit light in red, green, and blue are sequentially applied to the grooves between the partition walls.

  The front panel and the back panel having the above structure face each electrode forming surface side, and the peripheral portion thereof is hermetically sealed with a sealing material, and the discharge space is exhausted to one corner of the back panel, and the discharge gas is discharged. An exhaust pipe for introduction is attached. After the discharge space is evacuated by an exhaust pump, a discharge gas composed of neon and xenon is introduced at a pressure of 50 KPa to 80 KPa, and a predetermined portion of the exhaust pipe is locally heated and melted to be hermetically sealed to complete the PDP. .

  The display electrode pair and the address electrode are orthogonal to each other, and the intersection is a discharge cell. These discharge cells are arranged in a matrix, and three discharge cells having phosphor layers emitting red, green, and blue light in the direction of the display electrode pair become pixels for full-color display.

  The operation of the PDP configured as described above will be described. An address discharge is generated by sequentially applying an address discharge voltage corresponding to display data between each scan electrode and the address electrode group. As a result, in the discharge cells arranged in a matrix, predetermined wall charges corresponding to display data are sequentially formed on the electrode surfaces for each scan electrode. When a sustain discharge voltage is applied between the display electrode pair, that is, between the scan electrode and the sustain electrode in a state where these wall charge patterns are maintained, a sustain discharge is generated in the discharge cell in which the wall charges are formed. The phosphor layer provided in the discharge cell emits light by ultraviolet rays generated by the sustain discharge, thereby displaying an image.

  In the PDP having such a configuration, electrodes such as a display electrode pair and an address electrode as a display member, a light shielding layer, a partition, and the like are uniform in width, arrangement pitch, and the like over the entire surface of the front panel and the rear panel. Is required. As a method for forming these display members, patterning is performed by a so-called photolithography method in which a material containing a photosensitive resin is applied to the entire surface of a glass substrate, exposed through a photomask having a pattern corresponding to the display member, and then developed. Examples that are formed are common.

In the photolithography method, if dust or the like adheres to the exposed portion of the photomask, an unexposed portion where the photosensitive material corresponding to that portion is not exposed is generated. Therefore, when forming an electrode pattern etc. using a negative photosensitive material, an unexposed part melt | dissolves in a developing solution, and the disconnection of an electrode generate | occur | produces. As a method of preventing disconnection of the electrode due to dust adhering to the photomask, the exposure is performed twice, and the photomask is arranged in the longitudinal direction of the electrode pattern or the pattern pitch between the first exposure and the second exposure. A manufacturing method is disclosed in which the distance is moved by an integral multiple of (for example, see Patent Document 1).
JP 2004-265634 A

  In this way, when the exposure is performed twice and the photomask is moved by the distance in the longitudinal direction of the electrode pattern or an integral multiple of the pattern pitch between the first exposure and the second exposure, it adheres to the photomask. Exposure failure due to dust can be suppressed. However, in a portion not affected by dust, the cross-linking reaction proceeds excessively, resulting in overexposure. In a pattern that has been overexposed, stress is inherently present, and when baked in such a state, warping or peeling of the pattern occurs due to stress inherent in the edge portion of the formed pattern.

  On the other hand, if the exposure amount in the first exposure and the second exposure is reduced by half or reduced in order to prevent such overexposure, the dust portion is underexposed after only one exposure. In the case of underexposure, since the crosslinking reaction proceeds from the surface, curing is sufficient on the surface of the pattern, but curing is insufficient inside the pattern, and the pattern is easily peeled off in the development process and baking process. Issues arise.

  The present invention solves such problems, and when patterning display members such as PDP electrodes and barrier ribs by photolithography, the display member is prevented from warping and peeling and attached to the photomask. An object of the present invention is to provide a method of manufacturing a PDP that can prevent exposure failure due to dust.

  In order to achieve the above-described object, the PDP manufacturing method of the present invention includes a film forming step for forming a photosensitive material film serving as a display member, and exposure through a photomask having an opening pattern in the photosensitive material film. A PDP manufacturing method including an exposing step, wherein the exposing step exposes the photosensitive material film and the photomask with a first gap and a first exposure step after the first exposing step. And a second exposure step in which exposure is performed by moving the photomask along the opening pattern rather than the position of the first exposure step.

  According to such a method, even if dust adheres to the photomask, the exposure failure due to dust is eliminated, and overexposure and underexposure at the edge portion of the patterned electrode and the like are suppressed, and the pattern at the edge portion is suppressed. Warpage and peeling can be suppressed.

  Further, the photomask may have a periodic opening pattern, and the photomask may be moved by a distance corresponding to an integral multiple of the period of the periodic opening pattern in the second exposure step. According to such a method, the influence of dust attached to the photomask can be surely eliminated.

  Further, the photomask may have a stripe-shaped opening pattern, and the photomask may be moved in the longitudinal direction of the stripe-shaped opening pattern in the second exposure step. According to such a method, the movement and positioning of the photomask in the second exposure step can be easily performed, and furthermore, the influence of dust attached to the photomask can be surely eliminated.

  According to the method for manufacturing a PDP of the present invention, even when dust adheres to a photomask, it eliminates exposure failure due to dust, suppresses overexposure and underexposure at edge portions of patterned electrodes, etc. The warping and peeling of the pattern can be suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)
FIG. 1 is a perspective view of a main part of a PDP using a method for manufacturing a PDP according to an embodiment of the present invention. The PDP 10 includes a front panel 20 and a back panel 30. The front panel 20 includes a front glass substrate 21, and a plurality of display electrode pairs 24 including scan electrodes 22 and sustain electrodes 23 arranged in parallel are formed on the front glass substrate 21. The display electrode pair 24 has a structure in which a bus electrode made of a conductive material containing a metal material is laminated on a transparent electrode. Further, a light shielding layer 27 made of a black paint is provided between the display electrode pair 24 in order to improve contrast. A dielectric layer 25 is formed so as to cover the display electrode pair 24 and the light shielding layer 27, and a protective layer 26 is formed on the dielectric layer 25.

  The back panel 30 has a back glass substrate 31, and a plurality of address electrodes 32 arranged in parallel are formed on the back glass substrate 31. A base dielectric layer 33 is formed so as to cover the address electrodes 32, and striped barrier ribs 34 for partitioning the discharge space are formed thereon. On the side surface of the partition wall 34 and the underlying dielectric layer 33, a phosphor layer 35 that emits light in red, green, and blue colors is sequentially provided for each address electrode 32.

  The front panel 20 and the back panel 30 are arranged to face each other so that the display electrode pair 24 and the address electrode 32 intersect each other with a minute discharge space interposed therebetween, and the outer peripheral portion thereof is sealed with a sealing material such as glass frit. It is worn. In the discharge space, a mixed gas such as neon (Ne) and xenon (Xe) is sealed as a discharge gas. The discharge space is divided into a plurality of sections by barrier ribs 34, and discharge cells 36 are formed at portions where the display electrode pairs 24 and the address electrodes 32 intersect. When a discharge voltage is applied between the scan electrode 22 and the sustain electrode 23 constituting the display electrode pair 24, discharge occurs in the discharge cells 36, and the phosphor layer 35 is excited by ultraviolet rays generated by the discharge. The light is emitted and a color image is displayed. Note that the PDP 10 is not limited to the above-described structure, and may have a structure including, for example, a cross-shaped partition wall.

  The display electrode pair 24 formed on the front glass substrate 21 is formed by the following method. A transparent electrode layer made of, for example, ITO is formed on the front glass substrate 21 by an electron beam evaporation method or the like, and a photosensitive resist is applied on the surface thereof. Light from the ultraviolet light source exposes the photosensitive resist through a photomask for forming a transparent electrode pattern. After the exposed photosensitive resist is developed, the transparent electrode layer is etched, and then the photosensitive resist is peeled to form a transparent electrode constituting the striped display electrode pair 24 having a predetermined period.

  And the black electrode layer and conductor layer which comprise a bus electrode are formed in the surface of the transparent electrode formed as mentioned above. The black electrode layer is formed by screen printing a photosensitive black paste containing a black pigment, glass frit, a polymerization initiator, a photocurable monomer, and an organic solvent. For the conductor layer, after the black electrode layer is dried, a photosensitive Ag paste containing Ag powder, glass frit, a polymerization initiator, a photocurable monomer, and an organic solvent is screen-printed on the black electrode layer by a screen printing method or the like. Is formed. After drying the conductor layer, the black electrode layer and the conductor layer are patterned by a photolithography method including an exposure step and a development step, and further baked to form a bus electrode on the surface of the transparent electrode. Through the above steps, the display electrode pair 24 including the transparent electrode and the bus electrode is formed.

  The address electrode 32 formed on the rear glass substrate 31 is formed by the following method. As the address electrode material, for example, a photosensitive Ag paste is applied by screen printing on the back glass substrate 31, and then patterned by photolithography, followed by baking to form stripe-shaped address electrodes 32.

  Striped partition walls 34 for partitioning the discharge space are coated with a photosensitive paste mainly composed of an aggregate such as alumina and glass frit on the surface of the underlying dielectric layer 33 by a screen printing method, a die coating method, or the like. It is formed by baking after patterning by photolithography.

  On the other hand, the display members of the PDP 10, such as the display electrode pair 24, the light shielding layer 27, the address electrode 32, and the partition wall 34, are large and have a large area pattern, and at the same time, the shape accuracy and the position accuracy are strictly required. Therefore, the photolithography method is frequently used for patterning the display member constituting the PDP 10 as described above.

  Next, a method for manufacturing a PDP according to an embodiment of the present invention will be described in detail with reference to the drawings, focusing on the exposure step, taking as an example the case where the address electrode 32 of the PDP 10 is formed. FIG. 2 is a diagram showing a process of forming the address electrode 32 by the PDP manufacturing method in the embodiment of the present invention.

  First, as shown in FIG. 2A, a photosensitive Ag film is formed by uniformly applying a photosensitive Ag paste as a base material of the address electrode 32 on the rear glass substrate 31 by a screen printing method or the like. An Ag paste film 41 is formed. Next, as shown in FIG. 2B, a photomask 42 having a predetermined pattern corresponding to the pattern shape of the address electrode 32 is set at a predetermined position. The photomask 42 has an opening 43 having an opening pattern corresponding to the pattern of the address electrode 32, and the photosensitive Ag paste film 41 is exposed through the opening 43.

  Next, as shown in FIG. 2C, the first exposure step is performed so as to have an exposure gap G1 serving as a first gap between the photosensitive Ag paste film 41 and the photomask. In this case, the ultraviolet light 44 emitted from the ultrahigh pressure mercury lamp is used as the exposure light. In this way, in the exposed region 46 exposed through the opening 43 in the photosensitive Ag paste film 41, the crosslinking reaction proceeds to be cured. In this way, the first exposure step is completed.

  Next, the second exposure step shown in FIG. In the second exposure step, the photomask 42 is moved downward so that the second exposure gap G2 that is the second gap is smaller than the exposure gap G1 in the first exposure step. Further, in the second exposure step, exposure is performed by moving the photomask 42 along the opening pattern from the position of the first exposure step. Here, moving along the opening pattern means, for example, that when the opening 43 is a stripe-shaped opening, the photomask 42 is moved in the longitudinal direction, and further has periodicity. In the case of a periodic opening pattern, the pattern is moved in the direction of the periodic array by a distance that is an integral multiple of the period.

  By these first exposure step and second exposure step, a photosensitive Ag paste film 41 having a pattern cured corresponding to the address electrode 32 by the ultraviolet light 44 that has passed through the opening 43 is obtained. Next, a pattern of the photosensitive Ag paste film that becomes the address electrode 32 having a predetermined pattern is obtained by a development step of developing the photosensitive Ag paste film 41, and the address electrode is obtained by baking the photosensitive Ag paste film. 32 is completed.

  FIG. 3 is a diagram showing details of the exposure step by the PDP manufacturing method according to the embodiment of the present invention, and shows the exposure light when the exposure gap, which is the gap between the photomask 42 and the photosensitive Ag paste film 41, is changed. The relationship between the optical path and the exposure width is shown. As shown in FIG. 3, in the exposure step, the ultraviolet light 44 that passes through the opening 43 of the photomask 42 and travels toward the photosensitive Ag paste film 41 has a spread angle (collimation half angle). Therefore, if the exposure gap G2 at the time of exposure in the second exposure step is made smaller than the exposure gap G1 at the time of exposure in the first exposure step, the exposure at the second exposure step is smaller than the exposure width W1 at the first exposure step. The width W2 can be reduced. The exposure width W1 corresponds to the electrode width of the address electrode 32. That is, since the exposure width W2 in the second exposure step is smaller than the exposure width W1 in the first exposure step, only one exposure is performed at the edge portion 50 of the electrode, and excessive exposure of the edge portion 50 is suppressed. Thus, electrode peeling at the edge portion 50 can be prevented. On the other hand, since the number of exposures is two at the center of the electrode thicker than the edge part 50, the underexposure can be solved.

  In the PDP manufacturing method according to the embodiment of the present invention, the exposure gap is changed and the position of the photomask is moved in the second exposure step. A specific example of moving the photomask will be described with reference to FIG. FIG. 4 is a plan view showing the arrangement of photomasks used in the PDP manufacturing method according to the embodiment of the present invention.

  4A shows the arrangement of the photomask 42 in the first exposure step, and FIG. 4B shows the arrangement of the photomask 42 in the second exposure step. FIG. 4 illustrates an example in which the address electrode 32 is formed as in FIGS. 2 and 3. FIG. 4 is a plan view of a photomask 42 set above a photosensitive Ag paste film 41 as an exposure object. Dust adhering to the opening 43 is defined by using an unhatched portion of the photomask 42 as an opening 43. 45 is schematically shown.

  As shown in FIG. 1, the address electrodes 32 are formed with a periodicity at a predetermined pitch. Therefore, the opening 43 provided in the photomask 42 shown in FIG. 4 also has a periodic opening pattern. When the photosensitive Ag paste film 41 is exposed with the arrangement of the photomask 42 shown in FIG. 4A, the photosensitive Ag paste film 41 immediately below the dust 45 is not exposed and becomes an unexposed portion.

  Next, as shown in FIG. 4B, in the second exposure step after the first exposure step, the photomask 42 is moved in the direction of the arrow by one cycle of the address electrode 32, and as shown in FIG. Then, exposure is performed by vertically moving the photomask 42 so as to approach the photosensitive Ag paste film.

  Therefore, the areas A and B corresponding to the dust 45 of the photosensitive Ag paste film 41 are not exposed in the first exposure step, but the position corresponding to the dust 45 on the photosensitive Ag paste film 41 is moved in the second exposure step. Thus, the areas A and B are exposed. On the other hand, in the second exposure step, the areas M and N that are not exposed by the dust 45 are newly generated in the areas M and N that are shifted by one cycle of the exposure pattern, but the areas M and N are already in the first exposure step. Has been exposed.

  That is, when the photomask 42 is moved, the probability that dust is located at the same position before and after the movement with respect to the photosensitive Ag paste film 41 is very small. Therefore, if at least the photomask 42 is moved and exposure is performed twice before and after that, the area where the exposure is blocked by the dust 45 adhering to the photomask 42 and unexposed can be reduced.

  In FIG. 4, the photomask 42 is moved in a plane perpendicular to the longitudinal direction of the address electrode 32, but since the address electrode 32 has a stripe shape, it is longer than the average size of the dust 45. The unexposed area due to the dust 45 can also be eliminated by moving it by a large distance.

  In the above-described embodiment of the present invention, the case where the exposure gap in the second exposure step is made smaller than the exposure gap in the first exposure step has been described, but the exposure gap in the first exposure step is set to the second. You may make it smaller than the exposure gap in an exposure step. That is, the exposure gap in the second exposure step may be set so that a desired electrode width is obtained.

  In the above description, after the exposure in the first exposure step, the photomask is moved and the exposure in the second exposure step is performed. However, the photomask is fixed and the rear glass substrate is moved in the vertical direction or the plane direction. Even if it makes it, the same effect is acquired.

  In the above description, the address electrode is taken as an example. However, a display of a PDP formed using a photolithography method such as a scan electrode and a sustain electrode constituting a display electrode pair, and a light shielding layer and a partition wall of a rear panel. The patterning of the member can be performed in the same process, and the same effect can be obtained.

  According to the method of manufacturing a PDP according to the present invention, it is possible to prevent pattern defects caused by dust adhering to a photomask by suppressing warping of a display member such as a finely patterned electrode and peeling from a substrate. It is useful as a method for manufacturing an area image display device.

The perspective view of the principal part of PDP using the manufacturing method of PDP in embodiment of this invention The figure which shows the process of forming the address electrode by the manufacturing method of the PDP The figure which shows the detail of the exposure step by the manufacturing method of the PDP The top view which shows arrangement | positioning of the photomask used for the manufacturing method of the PDP

Explanation of symbols

10 PDP
DESCRIPTION OF SYMBOLS 20 Front panel 21 Front glass substrate 22 Scan electrode 23 Sustain electrode 24 Display electrode pair 25 Dielectric layer 26 Protective layer 27 Light-shielding layer 30 Back panel 31 Rear glass substrate 32 Address electrode 33 Base dielectric layer 34 Partition 35 Phosphor layer 36 Discharge Cell 41 Photosensitive Ag paste film 42 Photomask 43 Opening 44 Ultraviolet light 45 Dust 46 Exposure area 50 Edge part

Claims (3)

A method for manufacturing a plasma display panel, comprising: a film forming step for forming a photosensitive material film to be a display member; and an exposure step for exposing the photosensitive material film through a photomask having an opening pattern, wherein the exposure is performed. A step of exposing the photosensitive material film and the photomask with a first gap, and a second gap different from the first gap after the first exposure step. And a second exposure step of performing exposure by moving the photomask along the opening pattern rather than the position of the first exposure step. The photomask has a periodic aperture pattern, and the photomask is moved by a distance corresponding to an integral multiple of the period of the periodic aperture pattern in the second exposure step. A method for manufacturing a plasma display panel. 2. The method of manufacturing a plasma display panel according to claim 1, wherein the photomask has a stripe-shaped opening pattern, and the photomask is moved in a longitudinal direction of the stripe-shaped opening pattern in the second exposure step. .

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