JPH11354018A - Rib forming method for plasma display panel back plate and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the forming method of a rib of a plasma display panel back plate, capable of forming in a lump with high productivity and high efficiency. SOLUTION: A viscous rib material sheet 20 is flatly formed on a back glass substrate 11, a forming roll 30 having grooves 31 corresponding to a plurality of ribs 14 is pressed against the back glass substrate 11 and rolled to form a plurality of ribs 14 at the same time. A plasma display panel back plate having a plurality of ribs 14 on the back glass substrate 11 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the formation of a rib on a rear panel of a plasma display panel which can efficiently produce a rear panel of a plasma display panel as a constituent unit of the plasma display panel as an image display device. Method and apparatus.

[0002]

2. Description of the Related Art Plasma display panels (PDs)
P) is large, thin, lightweight, and capable of displaying high-definition images compared to CRTs.
Among displays (FPD), it is receiving attention as a display for the next generation.

The constituent units of the PDP can be roughly classified into two parts, a front panel and a rear panel. In the cell structure diagram of the AC type color PDP shown in FIG. 15, 1 is a front panel and 10 is a rear panel. The front plate 1 is provided with a dielectric layer 5 and a protective layer 6 behind a front glass plate 2 with a common electrode 3 and a scanning electrode 4 interposed therebetween. The rear plate 10 is provided with an address electrode 12 and a dielectric layer 13 on the front side of a rear glass substrate 11, and a rib (partition) 14 is formed on the front surface of the dielectric layer 13 so as to partition between the address electrodes 12. . A phosphor R is provided between the ribs 14.
(Red), phosphor G (green), and phosphor B (blue). The top of the rib 14 is in contact with the protective layer 6.

The manufacturing process consists of a front plate manufactured mainly using thin film technology and photolithography technology used in semiconductor manufacturing technology, and a back plate manufactured by combining thin film and photolithography technology with thick film technology. Can be classified into face plates.

[0005] In a situation where PDPs have been further enlarged and patterns have been refined, various manufacturing methods for forming ribs on the back plate have been proposed, including a screen printing method described below. However, at present, it is particularly difficult to meet the required pattern accuracy.

(1) Screen printing method FIG. 16 is a schematic view of a rib forming method by a screen printing method.
Shown in In the drawing, reference numeral 80 denotes a screen, 81 denotes a screen frame having a screen, and 82 denotes a squeegee. A rib paste which solidifies to form the ribs 14 is applied to the rear glass substrate 11 as a printing material through the screen 80.

[0007] The rib formation by the screen printing method is a method of transferring a rib paste that has passed through a screen 80 patterned in a rib shape to a back glass substrate 11 of a PDP back plate, so that film formation and patterning can be performed simultaneously. The feature is that the waste of the paste is small and the manufacturing cost can be relatively easily reduced.

[0008] However, the screen printing method has the following problems.

In order to form the required rib height of 150 μm, lamination printing is required 10 to 15 times, and it is necessary to repeatedly execute printing and drying, and the lead time is long.

It is necessary to repeat the alignment between the printing position and the back glass substrate 11 for each lamination printing, and the repetition error of the alignment greatly affects the accuracy of the rib pattern.

Screen printing requires a clearance between the screen and the substrate in order to improve the separation of the plate during printing. The screen is stretched by a squeegee during printing, and the screen is distorted. As a result, the accuracy of the rib pattern is reduced. Getting worse.

The screen is made by bonding a mesh made of stainless steel or polyester to the screen frame with a high tension. When the screen is stretched by a squeegee for each screen printing, the tension is reduced and the rib pattern changes plastically. This decrease in tension and plastic deformation are also major factors that reduce pattern accuracy and reproducibility. This is a fundamental problem of the screen printing method.

As the size of the PDP increases and the pattern area increases in proportion, it is necessary in principle to increase the clearance of the screen. Further, the distortion of the screen increases, and the pattern accuracy tends to deteriorate.
This is also a fundamental problem of the screen printing method.

In the screen printing method, it is customary to use a screen frame having a size about 4 to 6 times larger than the effective area of the pattern. When the size of the PDP is increased, the size of the screen frame is further increased. The device becomes larger, leading to an increase in manufacturing cost.

(2) Sandblast method FIG. 17 is a schematic view of a rib forming method by the sandblast method.
Shown in In this sandblasting method, as shown in FIG. 3A, the entire surface of the pattern effective area of the rear glass substrate 11 in the PDP rear plate is repeatedly screen-printed and laminated up to the required rib height, or the rib height is set in advance. The formed rib sheet is attached to the rear glass substrate 11 to form a rib material 8.
5 is formed on the substrate, and then a photoresist 86 is adhered to the surface of the rib material 85, and a mask 87 having a required pattern is overlapped as shown in FIG. 7B, and the photoresist 86 is exposed to ultraviolet rays (UV exposure). After development as shown in FIG.
Using the photoresist 86 remaining after the development as a mask as shown in FIG. 9D, only unnecessary portions as ribs are removed by sandblasting by spraying abrasives, patterning is performed, and a resist stripping process is performed as shown in FIG. This is a method of forming a rib 14 having a required pattern.

However, the sandblasting method has the following problems.

It is difficult to determine the end point of patterning, and the stability is poor.

The ratio of the unnecessary rib material is large, and the utilization rate of the rib material is poor.

Since the abrasive is sprayed, the cleanness is poor and the substrate needs to be cleaned.

(3) Lift-off method FIG. 18 is a schematic view of a rib-forming method by the lift-off method. This lift-off method uses a photoresist 90 until the rib height required for the PDP back plate is reached as shown in FIG.
Is laminated on the rear glass substrate 11 several times.
The photoresists 90 are laminated, and a mask 93 having a required pattern is superimposed on the photoresist 90 as shown in FIG. 3B, and the photoresist 90 is collectively exposed (UV exposed) with ultraviolet rays, and developed as shown in FIG. The same figure (D), leaving only the resist 90 part
A rib paste 92 as a rib material is buried in the groove 91 from which the photoresist has been removed as shown in FIG. 1, and after drying and curing and surface polishing, the photoresist is peeled off using a peeling liquid as shown in FIG. How to

However, the lift-off method has the following problems.

Photoresist 9 thickened by bonding
It is in principle difficult to expose all 0's and pattern them at high aspect ratio (resist thickness / line width).

The adhesion of the rib material to the substrate 11 is poor.

It is difficult to improve the solvent resistance and alkali resistance of the rib material against the photoresist stripping solution.

(4) Photo Paste Method FIG. 19 is a schematic view of a rib forming method by the photo paste method.
Shown in This photo paste method is characterized in that the rib paste or the rib sheet itself is given photosensitivity. First, as shown in FIG. 9A, a photosensitive paste 95 is formed on the back glass substrate 11 by solid printing or pasting a rib sheet with a rib paste, as shown in FIG. Are exposed by ultraviolet rays (UV exposure) to form a rib pattern, a photosensitive rib material 95 is laminated thereon as shown in FIG. 9C, and a mask 96 is superposed as shown in FIG. Exposure. Thereafter, the photosensitive rib material laminate of FIG. (C) and the ultraviolet exposure of FIG.
Unnecessary portions are removed by the development in FIG.

However, unlike a general non-filler photoresist, the photo paste for ribs needs to have a high filler content, and the higher the filler content, the worse the light transmittance. It is difficult in principle to achieve compatibility between a filler-rich paste and a highly photosensitive paste, and patterning with a film thickness of about 50 μm is the limit in a single exposure.

Other problems of the photo paste method include the following.

It is necessary to repeat the film formation / exposure / phenomenon of the photo paste several times, and the pattern accuracy is deteriorated due to the repetition error of the alignment.

The photo paste is more expensive than other methods of rib paste.

A large amount of rib material waste is generated by development, and the material utilization is poor.

In order to maintain photosensitivity, there are many restrictions on the fillers that can be used in the paste.

[0032]

The technical elements required for the method of forming the ribs of the PDP back plate are as follows.

(1) Large screen and easy high-precision and high-definition PDPs have a large screen diagonal of 20, 40 and 50 inches and display resolutions of SVGA, XGA and HDTV. Are required at the same time. Under such circumstances, the method of forming the ribs on the back plate also requires a large substrate size, high precision, and a narrow pitch. However, at present, it is difficult for the prior art method to easily meet these demands. Also, the cross section of the rib has a high aspect ratio (height / width)
This also makes it difficult to respond.

(2) Processing of the optimum cross-sectional shape is possible. The color PDP is R (red) G (green) B partitioned by ribs
(Blue) This is a display utilizing the property that phosphors of three colors emit light by ultraviolet rays. In order to improve display contrast as a display, various measures including improvement of the phosphor itself are being studied. . As one of the measures, the cell shape for the phosphor to emit light efficiently is also an important factor, and since the cross-sectional shape of the rib directly affects the shape of the light emitting surface of the phosphor, the rib cross-sectional shape is used for light emission. A method that can be formed into an optimal shape is desirable.

However, the conventional method can cope only with the rectangular rib cross-sectional shape, and the luminous efficiency of the phosphor cannot be optimized.

(3) The manufacturing method is simple, and the molding can be performed quickly and inexpensively. The rib forming method according to the prior art requires the same process to be repeated a plurality of times. Also leads to. Further, repeating the alignment for each process is a major factor in deteriorating the rib pattern accuracy due to the alignment error.

Further, in the lift-off method and the photo paste method, a large amount of expensive materials such as a photoresist and a photo paste are used, and a large amount of waste is generated at the same time. Connect. Further, the cost is increased because a large number of expensive devices such as a large-sized exposure / development / etching device are required.

In view of the above, the present invention provides a method and an apparatus for forming ribs on a plasma display panel back plate which can efficiently form the ribs on the plasma display panel back plate collectively with good productivity. The purpose is to:

Other objects and novel features of the present invention will be clarified in embodiments described later.

[0040]

According to a first aspect of the present invention, there is provided a method of forming a plurality of ribs on a rear substrate, the method comprising: forming a plurality of ribs on a rear substrate; A viscous rib material sheet is formed flat on the substrate, and a forming roll having grooves corresponding to the plurality of ribs is rotated while being pressed against the back substrate to simultaneously form the plurality of ribs. .

According to a second aspect of the present invention, there is provided a method for forming a plurality of ribs on a rear substrate, wherein the rib material sheet is formed flat on the rear substrate and dried and cured. An unnecessary portion of the rib sheet is cut by a rotating multi-blade cutter to simultaneously form the plurality of ribs.

According to a third aspect of the present invention, there is provided a rib forming apparatus for forming a plurality of ribs on a back substrate, comprising: a forming roll having grooves corresponding to the plurality of ribs; Means for rotating the forming roll against the rear substrate on which the rib material sheet is formed flat and rotating the pressing roll in a linear manner.

According to a fourth aspect of the present invention, there is provided a plasma display panel rear plate rib forming apparatus for forming a plurality of ribs on a rear substrate, wherein a multi-blade cutter and a rib material sheet are formed flat and dried and cured. Means for rotating the multi-blade cutter along the back substrate to move linearly relative to the back substrate.

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the method and apparatus for forming ribs on the back plate of a plasma display panel according to the present invention will be described below with reference to the accompanying drawings.

The first embodiment of the present invention will be described with reference to FIGS. 1 to 9 in the case where a stripe rib pattern is formed on an AC type PDP back plate. First, as shown in FIGS. 1A and 2, the back glass substrate 11 on the PDP back plate is used.
A viscous and flat rib material sheet 20 like viscosity is formed directly or by transfer over the entire effective area of the PDP rib pattern. The rib material sheet 20 contains glass powder as a main component and contains an organic binder and an organic solvent, and is a material that becomes an insulating sintered body after firing in a later step.

Next, as shown in FIGS. 1B and 3, a forming roll 30 having grooves 31 having a rib-shaped cross section at desired equal intervals is used in parallel with the outer periphery of the surface of the cylindrical roll. The rib material is forcibly pressed into the groove 31 on the forming roll 30 by rotating the roller 30 while pressing it against the back glass substrate 11 and linearly moving (in other words, moving the roll axis in parallel), as shown in FIG. C) and the rib material sheet 20 being deformed into a rib shape as shown in FIG. 3, the ribs 14 are formed on the rear glass substrate 11 at one time (simultaneously formed). At this time, a method of heating the forming roll 30 is also effective to improve the formability. After molding, the rear glass substrate 11 is dried and fired to complete the ribs 14,
The required stripe rib pattern of the AC type PDP back plate in which a number of ribs 14 are arranged in parallel is obtained.

At the time of rib formation, the thickness of the rib material sheet 20 is
It is necessary that the cross-sectional area of the flat rib material sheet 20 is equal to or slightly larger than the cross-sectional area of the rib after completion. As shown in the schematic diagram of FIG. 5, it is assumed that the rib tip width is 30 μm, the rib bottom width is 50 μm, the rib height is 150 μm, and the rib arrangement pitch is 150 μm.
When forming the ribs 14 having a thickness of μm, a rib material sheet having a thickness of about 40 μm is required.

As shown in FIG. 6, the forming roll 30 may be an integrated processing roll formed of a mold in which a groove 31 having a rib-shaped cross section is collectively formed on the outer periphery of a cylindrical roll, or a shape corresponding to one pitch of ribs. 、 Thin disk processed on the outer edge 3
It is also possible to use a split roll composed of a mold in which the two are combined, or a roll or the like in which only the outer periphery of the roll is made of a fluorine-based resin and the resin portion is processed with a rib groove. In the case where the roll surface material is metallic, it is possible to apply a surface treatment such as plating or fluorine to impart releasability when the rib material is separated from the forming roll 30.

As a method of forming the rib material on the rear glass substrate into a sheet shape, there is a rib material forming method by sheet transfer shown in FIG. 8, in which the rib material is continuously coated on the film 40 in advance by a doctor blade coating method or the like. Thereafter, a portion of the rib material unnecessary for the transfer is cut off to form a roll 41 of the rib material sheet 20, and the roll 41 of the rib material sheet 20 patterned into a square on the film 40 is fed out and transferred to the rear glass substrate 11. Transcribe by The film 40 after the transfer is wound by the winding means 43.

Another method for forming a rib material in a sheet shape on the back glass substrate is a direct coating method shown in FIG. 9. In this method, a rib material 55 is supplied from a rib material supply unit 50 to a nozzle 51 and the rib material is supplied to the nozzle 51. The nozzle 51 is moved along the substrate surface while ejecting the material 55 from the tip of the nozzle 51 to directly form the rear glass substrate 11.

As a combination of these methods, a direct coating method can be used as a method for forming a rib material on a film. In any of the methods, the rib material can be formed on the back glass substrate such that members on the manufacturing apparatus side, such as a transfer roll and a nozzle, are not in contact with each other.

According to the first embodiment, the following effects can be obtained.

(1) High-definition P, such as the cross-sectional shape of the rib 14, the pitch of the rib, the linearity of the rib, and the accuracy of the entire pattern.
The precision of the groove 31 of the forming roll 30 required for producing the DP with high precision is directly determined by the machining precision, and as a result, the rib 14 can be molded with high precision. Further, the rib formation method of the present embodiment can realize the rib formation with extremely high reproducibility.

(2) In the method according to the prior art, a rib is completed by repeatedly forming a rib component patterned in the same shape a plurality of times. Therefore, the completed rib cross-sectional shape is always rectangular. The rectangular shape of the rib is disadvantageous for efficiently emitting the phosphor between the ribs.

However, in the rib formation of the present embodiment, the rib shape for efficiently emitting light from the phosphor can be easily developed as a groove processing shape of a forming roll, and as a result, a PDP with high luminous efficiency is realized. it can.

(3) This embodiment is different from the conventional method in which the ribs are completed by repeating the same process, after the flat rib material sheet is formed on the rear glass substrate, and then the entire rib pattern is formed simultaneously (simultaneously). Molding) is possible, and a significant improvement in productivity can be realized.

A second embodiment of the present invention will be described with reference to FIGS. First, as shown in FIGS. 10A and 11, the PDP of the back glass substrate 11 on the PDP back plate
A flat rib material sheet 20 formed as a rib at a required height is formed on the entire surface of the rib pattern effective area by the sheet transfer shown in FIG. 8 or the direct coating method shown in FIG. The rib material sheet 20 contains glass powder as a main component and contains an organic binder and an organic solvent, and is a material that becomes an insulating sintered body after firing in a later step. Used.

After the rib material sheet 20 is dried and cured, as shown in FIGS. 10B and 12, a multi-dicing blade 60 in which a disk-shaped dicing blade 61 is fixed to a rotating shaft 62 with a rib pitch dimension. The rib material sheet 20 is linearly moved along the substrate surface while rotating at high speed (in other words, the axis 62 of the multi-dicing blade 60 is moved in parallel), and the rib material sheet 20 is diced to form the rear glass substrate 11.
By cutting off unnecessary parts of the upper rib material, FIG.
As shown in FIG. 13C and FIG. 13, the ribs 14 are molded at a time (simultaneously). After the molding, the rear glass substrate 11 is washed, dried, and fired to complete the ribs 14. Thus, a required stripe rib pattern of the AC-type PDP rear plate in which many ribs 14 are formed in parallel is obtained.

FIG. 14 is a schematic view of the multi-dicing blade 60. The dicing blade 61 fixed to the rotating shaft 62 at equal intervals is made of the same material as that used for dicing silicon wafers (using diamond abrasive grains). Can be used. The cross-sectional shape of the blade tip can be manufactured according to the cross-sectional shape of the rib.

According to the second embodiment, the rib 14
The precision of the dicing blade 61 and the precision of the fixed pitch required for producing high-definition PDPs with high precision, such as the cross-sectional shape of the ribs, the pitch of the ribs, the linearity of the ribs, the precision of the entire pattern, etc. Directly determined by
As a result, the ribs can be formed with high accuracy, and the ribs can be formed with very high reproducibility.

Further, the rib shape for causing the phosphor to emit light efficiently can be easily developed as the cross-sectional shape of the dicing blade 61, and as a result, a PDP with high light emission efficiency can be realized.

Further, after the flat rib material sheet 20 is formed on the rear glass substrate 11, the entire rib pattern can be formed at a time, and a significant improvement in productivity can be realized.

In the first embodiment, the means for linearly moving the forming roll having grooves corresponding to the ribs while pressing the forming roll against the rear glass substrate may be, for example, a spring member for pressing the forming roll against the glass substrate. And a mechanism such as an air cylinder for linearly moving the forming roll by rotating it on a substrate while pivotally supporting the forming roll.

Further, in the second embodiment, the multi-blade cutter is rotated along the back substrate which has been formed by forming a rib material sheet flat and dried and hardened, and is linearly moved relative to the back substrate. Means for causing this can be realized by a motor that rotates the multi-blade cutter at high speed, and a mechanism such as a moving table that linearly moves the substrate relative to the multi-blade cutter.

Although the embodiments of the present invention have been described above, it is obvious to those skilled in the art that the present invention is not limited to the embodiments and various modifications and changes can be made within the scope of the claims. There will be.

[0066]

As described above, according to the present invention,
The following effects can be obtained.

(1) High Definition, High Accuracy, and High Reproducibility The present invention produces a high definition PDP with high accuracy, such as rib cross-sectional shape, rib arrangement pitch, rib linearity, and overall pattern accuracy. The precision of the grooves of the forming roll, the precision of the dicing blade, and the precision of the fixed pitch, which are required for this, are directly determined by the machining precision, and as a result, the ribs can be molded with high precision. Furthermore, rib formation can be realized with very high reproducibility.

(2) Improvement of Luminous Efficiency In the method according to the related art, a rib is completed by repeatedly forming a rib component patterned in the same shape a plurality of times. Therefore, the completed rib cross-sectional shape is always rectangular. The rectangular shape of the rib is disadvantageous for efficiently emitting the phosphor between the ribs.
However, according to the present invention, a rib shape for efficiently emitting light from the phosphor can be easily developed as a groove processing shape of a forming roll or a cross-sectional shape of a dicing blade, and as a result, a PDP with high luminous efficiency is realized. it can.

(3) Improvement of Productivity by Batch Processing Unlike the prior art method of completing a rib by repeating the same process, the present invention forms a flat rib material sheet on a rear substrate and then collectively processes the entire rib pattern. Molding becomes possible,
Significant productivity improvement can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a first embodiment of the present invention.

FIG. 2 is a perspective view illustrating a rib material laminating step in the first embodiment.

FIG. 3 is a perspective view showing a roll forming step in the first embodiment.

FIG. 4 is a perspective view showing a completed state of a rib in the first embodiment.

FIG. 5 is a schematic diagram illustrating a relationship between a rib shape after roll forming and a rib material sheet thickness before roll forming according to the first embodiment.

FIG. 6 is a perspective view of an integrated processing roll that can be used in the first embodiment.

FIG. 7 is a perspective view of a division processing roll usable in the first embodiment.

FIG. 8 is a schematic diagram of a case where a rib material sheet is provided on a rear glass substrate by sheet transfer.

FIG. 9 is a schematic diagram of a case where a rib material sheet is provided on a rear glass substrate by direct coating.

FIG. 10 is a schematic diagram illustrating a second embodiment of the present invention.

FIG. 11 is a perspective view showing a rib material laminating step in the second embodiment.

FIG. 12 is a perspective view showing a multi-dicing molding step in the second embodiment.

FIG. 13 is a perspective view showing a completed state of a rib in the second embodiment.

FIG. 14 is a perspective view of a multi-dicing blade that can be used in the second embodiment.

FIG. 15 is a perspective view showing an AC type color PDP cell structure.

FIG. 16 is a schematic diagram illustrating rib formation by a conventional screen printing method.

FIG. 17 is a schematic diagram illustrating rib formation by a conventional sandblast method.

FIG. 18 is a schematic diagram illustrating rib formation by a conventional lift-off method.

FIG. 19 is a schematic diagram illustrating rib formation by a conventional photopaste printing method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 front plate 10 back plate 11 back glass substrate 14 rib 20 rib material sheet 30 forming roll 31 groove 40 film 42 transfer roll 43 winding means 50 rib material supply unit 51 nozzle 60 multi-dicing blade 61 dicing blade 62 rotating shaft

Claims (4)

[Claims] 1. A method of forming a plurality of ribs on a rear substrate, the method comprising: forming a plurality of ribs on a rear substrate; forming a viscous rib material sheet flat on the rear substrate;
A method of forming a rib on a rear plate of a plasma display panel, wherein a plurality of ribs are simultaneously formed by rotating a forming roll having grooves corresponding to the plurality of ribs while pressing the forming roll against the back substrate. 2. A method for forming a plurality of ribs on a rear substrate, the method comprising: forming a plurality of ribs on a rear substrate; forming a rib material sheet flat on the rear substrate; drying and curing the rib material sheet; Forming a plurality of ribs at the same time by cutting off unnecessary portions by a rotating multi-blade cutter. 3. A plasma display panel back plate rib forming apparatus for forming a plurality of ribs on a back substrate, comprising: a forming roll having grooves corresponding to the plurality of ribs; Means for rotating the forming roll while pressing the forming roll against the formed back substrate to move the forming roll linearly, wherein the rib is formed on the back plate of the plasma display panel. 4. A plasma display panel rear plate rib forming apparatus for forming a plurality of ribs on a rear substrate, comprising: a multi-blade cutter; a rib material sheet formed flat and dried and cured on the rear substrate. Means for rotating the multi-blade cutter along the blade to move the multi-blade cutter relatively linearly with respect to the back substrate.