JP3573022B2 - Method for forming dielectric and barrier ribs of plasma display panel - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and a material for forming a partition wall, or a dielectric layer and a partition wall, on a back plate of a plasma display panel, and more particularly, to a shape having a desired partition wall shape using a photocurable material. And how to.
[0002]
[Prior art]
What is the best regarding the structure and cross-sectional shape of the partition wall of the plasma display panel has not yet been determined.
[0003]
The basic planar structure of the partition wall in the AC type rear-reflection type, which is currently the mainstream, is the stripe structure illustrated in FIG. 1A. For example, the honeycomb type structure illustrated in FIG. -50768 (Fujitsu). The structure of the partition wall in the DC back reflection type developed by NHK and the like is a box-like structure as illustrated in FIG. 2A. The sectional shape of the partition is rectangular or trapezoidal in design. Further, as an improvement of the cross-sectional shape, a structure shown in FIG. 2B is disclosed in Japanese Patent Laid-Open No. 3-84832.
[0004]
The cross-sectional shapes of the partition walls are disclosed in FIG. 3 (a) rectangular, (b) trapezoidal, (c) inverted trapezoidal, and (d) those whose space portions are almost arc-shaped in design.
It is generally said that as a desirable cross-sectional shape, a shape close to a trapezoid is preferable in order to efficiently emit light emitted from the phosphor and to be less dependent on the viewing angle and enter the viewer's eyes. However, at present, there is a major proposition of improving the luminous efficiency, and it is unclear what kind of partition structure or cross-sectional shape is good for that purpose.
[0005]
However, the cross-sectional shape of the partition wall is often determined by the manufacturing method. At present, the method of manufacturing the partition walls has not yet been determined, but FIGS. 4 (a) and 4 (b) show a conceptual diagram of a widely used sandblasting method and a sectional shape of the partition walls by the method.
On the other hand, a method using a photocurable partition wall paste is being studied as a very promising production method in the future. This method initially required several or more coating and exposure steps to obtain the required partition wall thickness (100 to 200 μm). In this case, the sectional shape of the partition could be changed quite freely by sequentially changing the partition width of the photomask used in each exposure. However, in order to improve the productivity, it is necessary to reduce the number of coating steps and exposure steps. At present, the required thickness can be obtained by one or two coating and exposure steps. One of the current problems with this method is that it is difficult to control the cross-sectional shape of the partition. That is, for example, in one application / exposure step, the shape of the partition wall becomes an inverted trapezoid. The reason is that as the exposure light goes deeper from the surface of the paste, it is absorbed and scattered and decreases. Hereinafter, this point will be described in more detail.
[0006]
Regarding a method of exposing and developing a predetermined partition pattern using a photo-curable partition material (JP-A-1-269534; JP-A-02-165538 (Sumitomo Metal Ceramics)), for example, the shape shown in FIG. It has been announced. The reason for this shape is that, since the exposure light is scattered and absorbed by the partition wall material, the intensity is reduced and the resin is not cured, so that the coating and the exposure are repeated as shown in FIG. 5B. However, as a practical matter, if the cured thickness is, for example, 10 μm, the cured width is reduced by about 10 μm at the upper end surface and the lower end surface of the thickness. In order to obtain a predetermined height (around 150 μm), at least several repetitions are required, which is a problem in terms of cost.
[0007]
JP-A-8-50811, JP-A-10-188825 (Toray) and the like describe methods which can improve this point and can form a partition wall having a required thickness by one exposure. The method is a method for suppressing scattering of exposure light in the partition wall material as low as possible. Specifically, in order to prevent exposure light from being scattered due to a difference in refractive index between various components in the photocurable material, it is generally assumed that the refractive index of an organic substance is 1.45 to 1.7, (Powder of a mixture of an inorganic material as an aggregate and a low melting point glass as a binder) has a refractive index of 1.5 to 1.65. As a result, it is stated that by using an ultra-high pressure mercury lamp (15 mW / square cm) exposure, the material could be cured to a thickness of 180 to 200 μm at an exposure amount of 10,000 mJ / square cm on the partition wall material surface. At that time, the width of the partition after firing was 25 μm at the minimum on the upper surface and 40 to 50 μm at the maximum at the base. In this case, the cross-sectional shape of the cured portion of the partition wall material should be determined by the intensity of the exposure light, the scattering angle, the transmittance of the photo-curable partition wall material, the degree of scattering, and the threshold for dissolution / insoluble during development. , Not listed. In the above-mentioned application, a partition having a slightly trapezoidal shape is obtained, but the shape is not controlled. That is, one of the problems in this improvement method is that it is difficult to make the sectional shape of the partition into a desired shape. In particular, it is difficult to obtain a desired trapezoid by this method.
[0008]
[Problems to be solved by the invention]
The present invention has been made in order to solve such problems, and the subject thereof is to use a photo-curable partition material to form a partition by exposure, development, and firing methods, as much as possible. It is an object of the present invention to provide a method capable of making the cross-sectional shape of the partition into various shapes including a trapezoid as much as possible with a small number of exposures.
[0009]
[Means for Solving the Problems]
In order to solve this problem, the present invention first provides a method for performing pattern exposure not only from the side of the partition wall material but also from the back side, that is, from the glass substrate side. In this case, the partition pattern of the photomask is set so that the cross-sectional shape of the cured partition becomes a desired shape. Width Are for front and back For glass substrate surface It is not plane symmetric but different. That is, a method of forming a partition wall using a photo-curable partition wall material, wherein a predetermined position matching the position of the electrode portion from both the partition wall material side (front) and the glass substrate side (back side) on the glass substrate. When exposing the pattern at the position, the partition pattern of the photomask for the front side Width And partition pattern of back side photomask Width But For glass substrate surface A method is provided that is not plane-symmetric.
[0010]
Further, the present invention provides a method for controlling the cross-sectional shape of a partition by adjusting the conditions of exposure from the front and back.
[0011]
Secondly, in the first aspect, a light-shielding dielectric layer or a light-shielding dielectric layer paste formed on a required portion other than the partition wall portion on the substrate is used as the back side photomask. And provide a method.
[0012]
Thirdly, in the first aspect, there is provided a method characterized in that a light-shielding electrode or a light-shielding electrode paste formed on a glass substrate is used as a backside photomask.
[0013]
Fourth, a method of forming a dielectric layer and a partition on a back plate of a plasma display, wherein a photocurable partition forming material is applied to a predetermined region, and a partition pattern of a photomask for a front side is applied. Width And partition pattern of back side photomask Width But For glass substrate surface After exposing from the side of the photo-curable partition wall material and the side of the glass substrate through a photomask having a predetermined partition pattern that is not plane-symmetric, and after development or after further baking, the dielectric layer paste is filled in the grooves between the partition walls. To form a dielectric layer and a partition for a plasma display, characterized by forming a dielectric layer by firing.
[0014]
Fifth, there is provided a method of forming a dielectric layer and a partition on a back plate of a plasma display panel. Almost all Apply curable dielectric material to Said Almost the entire surface is cured, then Almost on the whole surface A photo-curable partition wall forming material is applied to a predetermined thickness, and the partition pattern of the photomask for the front side is applied. Width And partition pattern of back side photomask Width But For glass substrate surface Exposure to a predetermined position matching the electrode from the side of the photocurable partition wall material and the side of the glass substrate through a photomask having a predetermined partition pattern that is not plane-symmetric, developed, baked, and a dielectric for a plasma display Provided is a method characterized by forming a layer and a partition.
[0016]
No. 6 First, fourth, 5 terms Wherein the film of the photo-curable partition wall material used in any one of the above (1) to (3) comprises not at least one layer having the same composition but at least two layers having different photocurable properties.
[0017]
No. 7 And the fourth Term The paste for the dielectric layer to be used in the curing, the paste is cured after injecting into the groove between the partitions, and then, the phosphor layer forming paste is injected between each partition. provide.
[0018]
No. 8 In the second 7 In the above item, there is provided a method characterized in that the color tone after firing of the dielectric layer paste to be injected is a color tone that improves the color purity of the color development of each color phosphor.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
A method of performing pattern exposure not only from the side of the partition wall material (front side) but also from the back side, that is, from the glass substrate side is disclosed.
For example, in the method disclosed in JP-A-8-171858, pattern exposure is performed from both sides. However, the front and back patterns are plane-symmetric, and the main purpose is to shorten the exposure time. In other words, the decrease in the exposure amount due to scattering or absorption causes the exposure from the front surface and the exposure from the back surface to act complementarily, so that curing proceeds efficiently and the exposure time is shortened.
[0020]
Also, Japanese Patent Application Laid-Open No. 9-306341 (Toray) describes a front-back exposure method. Also in this case, the patterns of the photomasks on the front and back sides are not explicitly shown, but are plane-symmetric as shown in the drawing. The main purpose is to form a partition having a high aspect ratio, and utilizes the complementary effect of the front and back exposure described above.
[0021]
In the present invention, the purpose of exposing from both the front surface and the rear surface is to control the cross-sectional shape of the partition unlike the above case. Therefore, in the present invention, the partition pattern of the photomask for the front surface and the back surface is used. Width To For glass substrate surface One feature is that the pattern is not plane-symmetric but is not plane-symmetric. For example, if the width of the partition pattern of the photomask on the rear surface is twice as large as that of the front surface, the width at the bottom (glass surface) is about twice as large as the width of the upper surface of the partition. Further, the cured cross section varies considerably depending on the parallelism of the exposure light, the exposure dose, and the photocurability of the partition wall material. One of the features of the present invention is to control the sectional shape of the partition wall by changing the exposure conditions. Another feature of the present invention is to change the photocurability of the partition wall material in the thickness direction.
[0022]
However, this method of front and back exposure cannot be used when forming a partition on a PDP substrate on which a normal dielectric layer is formed. Because the dielectric layer is a layer that covers almost the entire surface of the substrate covering the glass substrate and the electrode layer, and the partition walls are formed on the dielectric layer, but the dielectric layer is usually opaque or almost opaque . The reason is that it is desirable that the dielectric layer has a high visible light reflectance in order to reflect as much as possible the light emitted from the phosphor layer formed thereon. The whiteness of a commercially available dielectric layer is about 80, which is a reflectance similar to that of paper which is felt to be fairly white. Therefore, such a material for a commercially available dielectric layer having a high reflectance cannot perform exposure from the glass surface. Even if exposure is forcibly performed, scattering is so strong that it cannot be cured in a desired shape. In most cases, a dielectric layer is formed on the back plate of the current AC type PDP. Therefore, this was also a problem of the prior art.
[0023]
Claims of the invention To 5 The described invention provides a method of using a dielectric material having a high light transmittance in a non-fired state and a curable property, though a white dielectric layer having a sufficient reflectance is obtained upon firing. . In addition, a method is provided in which a cured pattern of a partition wall material is formed thereon without firing, and then the dielectric layer and the partition wall are simultaneously fired.
[0024]
As another measure, in claim 2, a method of using a patterned light-shielding dielectric layer or a dielectric layer paste formed on a substrate instead of using an ordinary photomask in claim 2 I will provide a. One of the advantages of this method is that no alignment operation is required when exposing from the back side. Another advantage is that there is no problem even if the scattering angle of light exposed from the back side is somewhat large. In this method, a light-impermeable layer is formed by using a dielectric layer having a low light transmittance or a paste thereof at a necessary portion other than the partition wall portion on the substrate and, if necessary, firing. A photo-curable partition material layer is formed thereon by coating or the like (on a portion of the substrate where partition walls are required), and then using a normal photomask from the surface (the side where the partition material is formed). Expose. Only the part where the dielectric layer is not formed on the glass substrate is exposed. That is, only the partition portion is exposed. In this case, the exposure position needs to be aligned with the pattern of the already formed dielectric layer or the paste material for the dielectric layer to such an extent that there is no problem in forming the partition walls. For this purpose, it is desirable to form an alignment mark at the same time when a dielectric pattern is formed. Thereafter, exposure is performed from the back side (the glass substrate side). In this case, a normal photomask is not used. The entire surface is exposed. The formed dielectric layer or its paste blocks exposure light and acts as a photomask. Therefore, no alignment is required, and no gap is formed at the boundary between the dielectric layer, its paste material layer, and the partition wall material.
[0025]
The dielectric layer and the paste material layer used here need to be capable of reducing the exposure light to such an extent that the photo-curable partition material on the dielectric layer is not cured during the exposure. It is desirable that the light transmittance is 10% or less. That is, it is desirable that the amount of light passing through is reduced to 10% or less. In the case of a paste material, the absorption of light can be adjusted by adding an ultraviolet absorber as described below.
[0026]
Currently, it is preferred that the dielectric layer be white. The reason is that light emitted from the phosphor is reflected as much as possible. The dielectric layer paste most suitable for the purpose of the invention according to claim 2 of the present invention absorbs ultraviolet rays for exposure before firing, and corrects white color having high reflectance or its fluorescent color when fired. Color tone. Examples of the ultraviolet absorber that absorbs ultraviolet rays before firing and burns out and becomes colorless when fired include organic dyes and ultraviolet absorbers used in pastes for ceramic multilayer boards. For example, there are azo dyes such as butter yellow, and ultraviolet absorbers such as anthraquinone and benzophenone. By adding these to a commercially available paste for a white dielectric layer, a paste that can achieve the object of the present invention can be obtained. The method of addition may be a method in which these ultraviolet absorbers are dissolved in a solvent, mixed with the paste, and sufficiently stirred.
[0027]
The dielectric layer is not limited to a photosensitive curable type, and any material may be used as long as it does not cause a problem even if a photocurable partition wall composition is applied thereon and does not cause a problem in development. What does not cure by crosslinking may be used. That is, a material that cures when the solvent evaporates may be used. However, it must be one that does not swell or dissolve in the solvent used in the photocurable partition wall composition or the developing agent. For example, when the solvent used for the photocurable partition wall material is a certain kind of organic solvent, and the developing agent is the same kind or another kind of organic solvent, the binder component for the dielectric layer is It is necessary that the organic solvent does not dissolve or swell. For example, a water-soluble binder such as ethylcellulose and polyvinyl alcohol that does not dissolve in an organic solvent can be used.
[0028]
However, as a practical matter, when the dielectric layer is cross-linked and cured, it is easier to select a photo-curable partition material thereon. As the organic component in the case of photocurable, those used for the photocurable partition wall material can be used. For example, an acrylic monomer, a photoreaction initiator, a paste control agent, and a solvent. Although the refractive indexes of these components are different, a compatible mixture shows a refractive index according to Abbe's law. In general, the organic components are selected so as to be compatible with each other. As an organic component of the two-pack curing type to which a curing agent is added, for example, there is an epoxy acrylate type.
[0029]
On the other hand, as the dielectric layer for shielding the exposure light when fired, a white type of dielectric paste currently available on the market can be used. For example, YPW022, 040, 060 and the like manufactured by Asahi Glass Co., Ltd. These have a light transmittance of 23 to 29% at a thickness of 10 μm. Therefore, the object can be achieved by setting the thickness to about 15 μm.
[0030]
Further, the present invention provides a method of using an electrode portion having a light shielding property or a pattern of an electrode portion paste as a back side photomask. In the case of a paste, a paste obtained by adding the aforementioned organic dye or ultraviolet absorber to a commercially available electrode paste can be used. When the electrode is formed by screen printing, the amount of addition may be considered with emphasis on light shielding properties. On the other hand, in the case of the photosensitive paste, if the amount of the ultraviolet absorber added is too large, curing becomes incomplete even when exposed. When the thickness of the electrode is 5 to 15 μm, the addition amount is preferably 0.03 to 0.1 wt%. In the case of a fired electrode, the light blocking rate is often insufficient with a normal silver paste. It is desirable that the fired product is black. For example, it is an electrode paste containing iron oxide, cobalt oxide, copper oxide and the like, and there is a commercially available silver electrode.
[0031]
The photo-curable partition wall material used in the present invention is basically preferably a material having little scattering and absorption of light. The composition of the material for that purpose is described, for example, in JP-A-10-188825.
[0032]
Claim To 5 The described material for forming a dielectric must have a high light transmittance before firing. As a method for increasing the light transmittance of the material for forming a dielectric layer, a method is used in which the components have the same light refractive index as much as possible. Specifically, the components of the material for forming the dielectric layer are composed of three components: glass frit, aggregate inorganic particles, and an organic component serving as a binder. In an actual paste structure, the binder component is composed of glass frit and aggregate inorganic material. Penetrating between fine particles. Therefore, it is preferable to minimize the difference in the refractive index between the binder component and the glass frit and between the binder component and the aggregate inorganic fine particles as much as possible.
[0033]
On the other hand, in order to increase the reflectance after firing, it is desirable to increase the difference in the refractive index between the glass frit and the aggregate. Therefore, it is desirable that the refractive index of the organic component be sandwiched between the two. Generally, low melting point glass is used for the partition walls, and has a refractive index of 1.5 to 1.65. The refractive index of the inorganic substance used as the aggregate is 1.7 to 1.84. Therefore, the refractive index of the organic component is set to 1.65 to 1.7.
[0034]
It is one of the present inventions to laminate two or more barrier materials having different photocuring properties as necessary. By doing so, it becomes easy to obtain a desired sectional shape of the partition wall, for example, as shown in FIG. Here, the photocurability means whether the exposed portion remains or does not remain when developed at a certain exposure amount. The light intensity distribution in the paste layer is determined by the light scattering and absorption of each component. Whether the polymer is cured and remains at the time of development or does not remain depends on the degree of curing polymerization, the solubility of the polymer in a developing solution, and the developing conditions.
[0035]
To actually adjust the light transmittance of the paste, it is convenient to change the amount of the ultraviolet absorbing component. When the amount of addition is increased, the cross-sectional shape of a portion remaining after development changes as shown in FIG.
[0036]
A partition layer in which the photocurability is reduced by increasing the amount of the ultraviolet absorber added to the photocurable partition material having a high transmittance of exposure light is used as a layer on the glass substrate side, and the amount of the ultraviolet absorber added thereon is reduced. A small amount of the original photo-curable partition wall material layer is formed on top of one another, and the exposure amount is adjusted from the front and back sides as shown in FIG. 7A, and exposure is performed, followed by development to obtain the shape shown in FIG. 7B. Performing the application twice or more does not pose a problem in terms of cost. This is because, in practice, when the coating is performed at a thickness of 50 μm or more at one time, troubles such as generation of cracks often occur at the time of drying the solvent, and therefore, it is hardly performed. In the application with a thickness of 150 to 200, the application is usually performed 3 to 4 times as a production process.
[0037]
FIG. 8 shows a general process when performing exposure from the back surface through a glass substrate. FIG. 8A shows a photomask for each of the front and back sides, and shows a process until a photosensitive partition material is applied to the glass substrate (electrodes are not shown). At this time, the photomask for the back surface is not simply adjusted to the size of the bottom surface of the partition wall, but has a pattern size that can ignore light scattering due to the thickness of the glass because the thickness of the glass is about 3 mm.
[0038]
In FIG. 8 (b), it is possible to shorten the process time if the exposure is performed simultaneously on the front and back, but there is no problem if the exposure is performed separately. Further, the intensity of the exposure light from one side does not need to be cured to the entire thickness of the partition wall material, but may be such that the partition wall material is cured as a result of exposure from both sides. Of course, the intensity and the exposure amount may be different on the front and back. Further, the distance between the photomask and the surface to be exposed and the scattering angle of the exposure light may be different.
FIG. 8C shows a sectional shape of the partition wall after development and firing. Although a trapezoidal cross section is shown, the cross sectional shape changes depending on the development conditions.
[0039]
Invitation An electric conductor layer is formed in two layers There is also a form . In general, a pinhole defect is a serious defect in a dielectric layer, and a method of forming a two-layer structure has been proposed. According to this method, this point is advantageous. Since the composition of the inorganic component of the dielectric layer is different between the composition that increases the reflectance: whiteness and the composition that does not generate defects such as pinholes, it is easier in design to form two layers.
[0040]
The method of pouring the dielectric layer paste after forming the partition walls has an advantage that the dielectric layer adheres not only to the glass substrate portion but also to the side surfaces of the partition walls, so that the effect of increasing the color purity is great. Has the advantages that the thickness of the layer is uniform and the amount of expensive phosphor used is small. Further, since a hardening type dielectric layer was used and the phosphor was poured without firing, the phosphor adhered well to the base.
[0041]
The exposure conditions include types of exposure light such as parallel light, slit light, and diffused light. Use these properly. Regarding the amount of exposure, a reciprocity law is generally established between the exposure intensity and the exposure time. In the light source, the emission wavelength is different between a mercury lamp (high pressure, ultra high pressure), a halogen lamp, and a laser (YAG, excimer, etc.). Mainly, the exposure amount and the degree of diffusion are properly used. For example, when exposing through a glass substrate, an apparatus having a high degree of parallelism, such as a laser beam, having a low degree of diffusion is used among parallel exposure apparatuses. There is also a method of using convergent light.
The type and amount of the light absorbing agent mixed in the partition wall forming material is also a kind of exposure condition.
[0042]
As a developing method, a spray method or an immersion method is used. The higher the height of the partition walls and the smaller the pitch, the more preferable the spray method. The composition of the developer varies depending on the organic component in the partition wall material.
[0043]
In the method of the present invention, in the case of baking only the partition, the partition and the dielectric layer may be simultaneously formed, the electrode and the dielectric and the partition may be simultaneously formed, and the electrode, the dielectric, the partition and the phosphor may be simultaneously formed. In the case where the temperatures of the burnout and sublimation of the organic matter are different from each other by about 10 ° C. or more, the holding time is set at each temperature. Further, the softening temperature of the glass frit is set to be lower by about 0 to 20 ° C. than that used for the member to cover the upper part. When a partition is formed and a dielectric layer is formed between them, it is preferable that both glass frit be the same.
[0044]
Exposure conditions for making the sectional shape of the partition into a trapezoid are as follows.
{Circle around (1)} The exposure apparatus used for exposure is preferably a parallel exposure apparatus, a converging exposure apparatus, or a laser exposure apparatus on the back side. On the front side, a point light source or a slit light source is preferable. In the case of a slit light source, the direction of the slit is preferably perpendicular to the direction of the partition.
{Circle around (2)} The amount of light from the back side is set to be two to three times the amount of exposure from the front side. The amount of exposure from the back surface is increased as the position deviates from the vertical.
{Circle around (3)} As the angle of the trapezoid changes from vertical to oblique, the amount of the light absorbing agent mixed into the partition paste increases.
[0045]
In addition, for the dielectric layer paste which has a color tone to correct the color of the color of the phosphor after firing, the color tone depends on the inorganic component, for example, SeCd and Fe2O3 for red, and CoAl2O4 for blue. Green includes Co (x) Cr (y) Ti (1-Z) Al2O4. The paste for a colored dielectric layer can be prepared, for example, by adding these inorganic pigment components to a commercially available paste for a white dielectric layer.
In the case of forming this colored dielectric layer, it is necessary to match with the color light of the fluorescent substance placed thereon. Therefore, instead of forming them all at once, they are formed sequentially for each color.
[0046]
【Example】
Hereinafter, the present invention will be described with reference to examples.
[0047]
<Example 1>
A mixture of 40 parts by weight of n-butyl methacrylate, 50 parts by weight of methyl methacrylate, and 10 parts by weight of 2-hydroxyethyl methacrylate was copolymerized using cyclohexanone as a solvent. The refractive index of the copolymer was 1.65. The weight ratio of the acrylic copolymer to cyclohexanone was adjusted to 1: 1. Then, using this composition (A), a photocurable composition (B) was prepared at the following compounding ratio. This composition can be used both for a partition of a PDP and for a dielectric layer.
[0048]
Composition A 10 parts by weight
6 parts by weight of dipentaerythritol pentaacrylate
1.2 parts by weight of triazine compound (photopolymerization initiator)
Cyclohexanone (diluting solvent) 30 parts by weight
Low melting point glass powder 27 parts by weight
Alumina powder (filler) 25 parts by weight
[0049]
Here, the refractive index of the low melting point glass powder is 1.60, and the refractive index of alumina (powder) is 1.75.
[0050]
First, as shown in FIG. 9 (a), a paste of the above composition was screened on a transparent glass substrate 1 using a stainless screen plate of 325 mesh having a rectangular opening of 100 mm × 150 mm and a plate thickness of 75 μm. Printed. This was left at room temperature for 15 minutes, then dried in a circulating hot air oven at 70 ° C. for 20 minutes, and finally cured by irradiation with ultraviolet rays. The cured product had a thickness of 10 μm. The light transmittance in this state was 60%.
[0051]
Next, the photocurable partition wall material (B) was coated on a glass substrate on which a cured product of the dielectric layer paste was formed, by applying 270 mesh having a 50 mm × 50 mm rectangular opening and a plate thickness of 85 μm. Was screen-printed using a stainless steel screen plate, and dried on a hot plate at 90 ° C. for 15 minutes. Further, the step of coating and drying the above-mentioned partition wall material thereon was repeated six times in total. The coating thickness was 140 μm. (FIG. 9B)
[0052]
As a photomask, a photomask 3 in which a linear light-shielding pattern having a width of 150 μm was repeatedly formed at a pitch of 200 μm, and a photomask 4 in which the pitch was the same and the width of the linear light-shielding pattern was 70 μm were prepared. The photomask 3 was brought into close contact with the glass substrate on the side where the partition material was coated, by aligning the exposure position, and was exposed using an exposure machine of an ultrahigh pressure mercury lamp. The exposure amount was 600 mJ / cm2. Next, the photomask 4 was brought into close contact with the exposed side of the glass substrate by aligning the exposure position with the glass side (FIG. 9 (c)). The exposure amount was 400 mJ / cm2.
[0053]
Subsequent to the exposure, development was carried out using a solvent in which 90 parts by volume of ethyl cellosolve and 10 parts by volume of ethyl carbitol were mixed as a developing solution, and the photocurable composition for partition walls in the unexposed portions was removed. Thereafter, the glass substrate was immersed in the order of ethyl alcohol and 2-propanol, washed, and dried. The thickness of the patterned photocurable resin for partition walls was 130 μm. In addition, no development residue or peeling phenomenon at the end was observed.
[0054]
The glass substrate is put into a firing furnace, and the temperature is raised to 450 ° C. at a rate of 4 ° C./min, held there for 60 minutes, then raised to 600 ° C. at 4 ° C./min, held for 15 minutes, and then held at 4 ° C. Per minute. By firing under these firing conditions, the resin component was burned off, and the dielectric layer and the partition having a trapezoidal cross section could be formed. (FIG. 9D)
[0055]
The thickness of the thus formed dielectric layer was 8 μm, while the shape of the partition wall was 45 μm at the top and 80 μm at the bottom, the thickness was 120 μm, and the cross-sectional shape was almost trapezoidal.
[0056]
<Example 2>
A case where a pattern is formed in a necessary portion other than the partition wall portion with a light-shielding dielectric layer paste and is used as a photomask on the glass substrate side will be described (FIG. 10).
[0057]
To the photocurable dielectric layer composition (B) prepared in Example 1 was added 0.1% by weight of butter yellow, which is a kind of azo dye, as an ultraviolet absorber. In addition, a screen printing plate having a partition wall pitch of 230 μm, an ink non-passing part being a partition part (width 90 μm) and a dielectric layer unnecessary part was prepared. Using this screen plate, the above photocurable dielectric composition was subjected to alignment screen printing on a PDP substrate on which electrodes were formed in consideration of the positional relationship with the electrodes (FIG. 10A). ). The thickness of the printed layer after drying was 15 μm. Next, the printed pattern was cured by irradiating ultraviolet rays from both sides of the substrate (FIG. 10B). The transmittance of the exposure light was 10%. A pattern of a dielectric layer having a width of 90 μm at the partition without the dielectric layer was obtained.
[0058]
Next, a barrier material having the same composition as in Example 1 was applied to the entire upper surface by a dry thickness of 150 μm (FIG. 10C). The entire surface was exposed from the back surface at an exposure amount of 4000 mJ / cm 2, and then exposed from the front surface using a photomask having a partition wall (width 40 μm) as a transparent part (FIG. 10D). The exposure amount was 2000 mJ / cm2. When spray-developed with a developer having the same composition as above, a partition material pattern having a substantially trapezoidal cross-sectional shape having a bottom width of 90 μm and a top width of 40 μm was obtained. The partition material on the dielectric layer was slightly cured, and remained on the dielectric layer with a thickness of several μm even after development. After firing, a dielectric layer having a thickness of 15 μm, a partition wall width of 90 μm at the bottom, 40 μm at the top surface, and a height of 130 μm was obtained (FIG. 10E). No crack was generated at the contact portion between the dielectric layer and the partition.
[0059]
<Example 3>
Using NB-2 and DC202, which are silver electrode forming materials manufactured by Du-Pont, a silver electrode having a black glass surface was formed on a glass substrate for PDP under conditions recommended by the manufacturer. The line width was 60 μm and the thickness was 15 μm.
[0060]
Next, in the same manner as in Example 2, the photosensitive partition material of Example 1 was applied to a dry thickness of 150 μm and dried, and exposed to 2,000 mJ / cm 2 from the back surface while masking unnecessary portions such as peripheral portions of the partition wall. Was exposed to a predetermined position at an exposure dose of 400 mJ / cm 2 using a photomask having a partition pattern (line width 35 μm, pitch 340 μm). Next, post-baking and development were performed in the same manner as in Example 2. The bottom surface of the partition wall was in contact with the silver electrode, and the width of the upper surface was 35 μm.
[0061]
Next, using a 400-mesh stainless screen plate and a screen printing machine, a plate was set so that the width of the opening of the emulsion was 200 μm and the position was exactly at the center of each cell between the partition walls. A doubled amount of the solvent was prepared from the dielectric paste of Example 1 and printed so that it flowed into each cell. The film thickness after drying was 10 μm. Upon firing, a partition wall with a width of 150 μm on the bottom surface, 35 μm on the top surface, 130 μm height, and a dielectric layer with a thickness of 8 μm were obtained.
[0062]
<Example 4>
In the third embodiment, an example is described in which a dielectric layer in which a coloring agent for increasing the color purity of color light emitted from each phosphor is added to the dielectric layer. In the preparation of the photocurable dielectric composition B of Example 1, the amount of the alumina powder was 10 parts by weight, the amount of the pigment component was 15 parts by weight, the amount of the solvent was about twice, The thickness of the paste of each color was adjusted so that the thickness after firing was substantially the same. Red pigments were red iron oxide, blue was cobalt aluminate, and green was Co (x) Cr (y) Ti (1-z) O4. The screen plate used had openings only for one color, and the other three colors of the dielectric paste were sequentially flowed into the openings of the partition under the same conditions as in Example 3. After drying, when the thickness of the dielectric layer was measured, it was about 10 μm on the bottom surface and about 5 μm on the side wall of the partition.
[0063]
After drying, a paste in which the phosphor was dispersed in a polyvinyl alcohol solution was poured into the space between the partitions by a screen printing method for each color by a usual method, dried, and fired. Since the dielectric layer and the phosphor layer were stacked in an unfired state and fired at the same time, the adhesion between the two was higher than that of a normal method.
[0064]
<Example 5>
The case where two types of partition materials having different photocurability are used will be described. As the photosensitive partition wall material, (B) of Example 1 and (C) to which 0.1 wt% of butter yellow was added as an ultraviolet absorber were used.
A photosensitive partition wall material (C) is applied to the PDP substrate on which electrodes are formed by applying a dry thickness of 70 μm. After drying, alignment exposure is performed using a photomask having a transparent lattice pattern as a photomask from the back surface. did. An exposure machine utilizing a second harmonic with a YAG laser was used. The exposure amount was 1500 mJ / cm2. Next, the photosensitive partition wall material (B) was applied on the photosensitive partition wall material (C) to a dry film thickness of 100 μm and dried. A photomask having a stripe-shaped partition wall width of 35 μm was used, and alignment exposure was performed from the surface using a parallel exposure machine.
When spray-developed, dried and baked, the lower part was a lattice-shaped partition having a considerably inverted trapezoidal shape, and the upper part was a stripe-shaped partition close to vertical (near rectangular).
[0065]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, when manufacturing the display which requires an insulating partition, such as a plasma display and a plasma addressed liquid crystal display, it becomes possible to manufacture a partition with high aspect ratio and high precision. Although there is a limit, it is a method that can make the cross-sectional shape of the partition wall closer to a desired shape to some extent.
[Brief description of the drawings]
FIG. 1 is a perspective view of the structure of an AC three-electrode PDP panel.
FIG. 2 is a perspective view of a structure of a DC auxiliary anode type PDP panel.
FIG. 3 is a sectional view of an example of a design shape of a partition wall.
FIG. 4 is a cross-sectional view showing formation and shape of a partition wall by a sandblast method.
FIG. 5 is a sectional view showing a method and a shape using a photocurable partition wall material.
FIG. 6 is an explanatory diagram showing the relationship between the amount of a light absorbing agent added to a photocurable layer and a cured portion (parallel light, constant exposure amount).
FIG. 7 is a cross-sectional view showing a cured portion when a low light absorbing partition wall material and a high light absorbing partition wall material are laminated and exposed from a front and back with a different pattern mask;
FIG. 8 is an explanatory view showing a method of forming a partition wall using a photosensitive partition wall material by a front and rear width partition wall pattern photomask;
FIG. 9 is a process explanatory view of Example 1.
FIG. 10 is a process explanatory view of Example 2 (a method of forming a partition by performing front and back exposure using a light-shielding curable dielectric paste as a photomask);

Claims (8)

A method of forming partition walls on a back plate of a plasma display panel using a photocurable partition wall material, wherein electrode portions are formed from both a partition wall material side (front side) and a glass substrate side (back side) on a glass substrate. exposure conditions upon pattern exposure at a predetermined position aligned, that partition pattern width of the barrier rib pattern width and the back photomask photomask for the front is not plane-symmetric with respect to the glass substrate surface, and the front and back surfaces and Controlling the shape of the partition wall after development by adjusting the shape of the partition wall. 2. A light-shielding dielectric layer or a light-shielding dielectric layer paste formed on a required portion of the glass substrate other than the partition wall portion as the back side photomask. 3. The method for forming a partition of a plasma display panel according to item 1. The method according to claim 1, wherein an electrode having a light-shielding property formed on a glass substrate or an electrode paste having a light-shielding property is used as the back side photomask. A method for forming a dielectric layer and barrier ribs on a back plate of a plasma display panel, comprising applying a photo-curable barrier rib material to a predetermined thickness on substantially the entire surface of the back substrate, wherein a predetermined thickness satisfying the condition of claim 1 is satisfied. Using a photomask having a partition pattern width , exposing and developing from the photocurable partition material side and the glass substrate side, or after further baking to form a partition for a plasma display, a dielectric A method for forming a dielectric and a partition of a plasma display panel, which comprises injecting a layer paste into a groove between the partitions and baking to form a dielectric layer portion. A method of forming a dielectric layer and barrier ribs on a back plate of a plasma display panel, comprising applying a curable dielectric forming material to substantially the entire surface of a back substrate on which electrodes are formed, and curing the substantially entire surface. Then, a photo-curable partition wall material is applied to the substantially entire surface at a predetermined thickness, and the photo-curable partition wall material is applied through a photomask having a predetermined partition pattern width satisfying the condition of claim 1. And exposure to a predetermined position matching the electrode from the side of the glass substrate, development and baking to form a dielectric layer and a partition for a plasma display, the dielectric and partition of the plasma display panel Forming method. Claims 1, in any of the 5, not further film of the photocurable rib material is the same composition, characterized in that it consists of a layer of the photocurable different at least two layers, a dielectric of a plasma display panel Method of forming body and partition. The dielectric paste used Oite to claim 4 and curable, and wherein the said paste is cured after injection into the grooves between the barrier ribs, for injecting Thereafter, the paste for the fluorescent layer formed between the barrier ribs 5. The method for forming a dielectric and barrier ribs of a plasma display panel according to claim 4 . 8. The method for forming a dielectric and barrier ribs of a plasma display panel according to claim 7 , wherein the color tone after firing of the dielectric paste to be injected is a color tone for improving the color purity of each color phosphor.

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