JP3283972B2 - Method for manufacturing plasma display panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a plasma display panel (PDP). Surface discharge type PDP suitable for full color matrix display by phosphor
Attention has been paid to a thin display device that replaces a CRT, and its high definition and large screen are being promoted in order to expand applications in the field of high-definition video.

[0002]

2. Description of the Related Art FIG. 4 is an exploded perspective view of a general surface discharge type PDP, and shows a basic structure of a portion corresponding to one pixel EG.

The PDP 10 illustrated in FIG. 4 has a three-electrode structure in which a pair of display electrodes X and Y and an address electrode A correspond to a unit light-emitting region EU of a matrix display. Discharge type P called reflection type
DP.

The display electrodes X and Y for surface discharge are provided on the glass substrate 11 on the display surface H side, and a discharge space is formed by a dielectric layer 17 for AC drive for maintaining discharge using wall charges. 30 coated. On the surface of the dielectric layer 17, MgO having a thickness of about several thousand
A membrane 18 is provided.

Since the display electrodes X and Y are arranged on the display surface H side with respect to the discharge space 30, the display electrodes X and Y are formed of a Nesa film or the like in order to widen the surface discharge and minimize the shielding of display light. A transparent conductive film 41 having a large width and a bus metal film 42 having a small width for supplementing the conductivity thereof.

On the other hand, an address electrode A for selectively emitting light in the unit light emitting region EU is provided on the glass substrate 21 on the rear side.
Above, they are arranged at a constant pitch so as to be orthogonal to the display electrodes X and Y.

[0007] Between each address electrode A, 100 to 15
A stripe-shaped partition wall 29 having a height of about 0 μm is provided, whereby the discharge space 30 is partitioned for each unit light emitting region EU in the line direction (extending direction of the display electrodes X and Y). The gap size is specified. Further, the glass substrate 21 covers the inner surface on the back side including the upper surface of the address electrode A and the side surface of the partition wall 29,
The phosphors 28 of three primary colors of R (red), G (green), and B (blue) are provided. Letters R, G, and B in the figure indicate the emission colors of the respective phosphors 28. The phosphor 28 emits light when excited by ultraviolet rays emitted from the discharge gas in the discharge space 30 during surface discharge.

Each pixel (dot) EG constituting the display screen
Are associated with three unit light emitting regions EU of the same area arranged in the line direction. In each unit light emitting region EU, a surface discharge cell (main discharge cell for display) is defined by the display electrodes X and Y, and the display electrode Y and the address electrode A
Thus, an address discharge cell for selecting display or non-display is defined. As a result, of the phosphors 28 continuous in the direction in which the address electrodes A extend, each unit light emitting area EU
Can selectively emit light at a portion corresponding to R,
Full color display is possible by a combination of G and B.

In the PDP 10 having the above structure, predetermined components are separately provided for each of the glass substrates 11 and 21,
It is manufactured by a series of steps of arranging the glass substrates 11 and 21 to face each other, sealing the periphery of the gap, and exhausting the inside and filling the discharge gas.

At this time, first, the address electrode A is provided on the glass substrate 21, and then the partition wall 29 and the phosphor 28 are provided in this order. By selecting the formation order in this manner, the address electrode A can be easily formed by using the thick film method, and the luminance can be increased by providing the phosphor 28 so as to cover the side surface of the partition 29. .

Conventionally, the partition walls 29 are formed by a step of applying a low-melting glass paste in the form of stripes using a screen printing method and a subsequent baking step. That is, the partition 29 having a predetermined plane pattern is formed by pattern printing using a screen mask.
Was getting.

[0012]

In the pattern printing by the screen printing method, it is difficult to reduce the width and the arrangement pitch of the partition walls 29, so that a high definition display cannot be expected. Further, when the display surface H is to be enlarged, it is impossible to make the arrangement relationship between the partition walls 29 and the address electrodes A uniform over the entire display surface H due to shrinkage of the screen mask or the like. Further, in order to obtain the partition wall 29 having a predetermined height, dozens of times of overprinting (lamination of pastes) is necessary, which is disadvantageous in terms of manufacturing man-hours, and easily loses shape during printing and firing. Discharge may be hindered.

Therefore, it is conceivable to provide a low-melting glass layer (so-called solid film) that uniformly covers the glass substrate 21 and pattern it using a photolithography method to form the partition 29. In this case, as a method for etching the low-melting glass layer, a sand blast method, a wet etching method, or the like can be used, but the wet etching method is useful in view of easiness of etching of a large area and required time.

However, in a normal wet etching method in which the low-melting glass layer is partially removed by simply using an etchant (an etching solution that corrodes the low-melting glass), the progress of etching is isotropic etching. For this reason, it is necessary to design a pattern in consideration of the amount of side etching, and there is a problem that a great increase in definition cannot necessarily be expected.

The present invention has been made in view of the above problems, and has as its object to facilitate the manufacture of a high definition plasma display panel.

[0016]

According to a first aspect of the present invention, there is provided a method for solving the above-mentioned problems, as shown in FIG.
Partition wall 29 that partitions discharge space 30 for each unit light emitting area EU
In the manufacture of the plasma display panel 1 having a low melting point, the low melting point glass layer 29c having a uniform thickness is formed on the substrate 21, and the low melting point glass layer 29c is formed by applying a photosensitive resist material and performing pattern exposure. A step of forming an etching mask 61 that partially covers the substrate, an etchant that corrodes the low-melting glass layer 29c,
An etching solution containing a mixture of an oily agent to be No. 1 and a surfactant 80 for facilitating the formation of the corrosion prevention film 71 is sprayed on the end surface S1 in the thickness direction of the low melting point glass layer 29c, and the low melting point glass Forming the partition 29 by partially removing the layer 29c.

A method according to a second aspect of the present invention is a method of arranging the substrate 21 with the end face S1 to be etched facing downward, and spraying the etching solution from below onto the end face S1. is there.

According to a third aspect of the present invention, there is provided the method of
An electrode A is formed on the substrate 1 and the substrate 2 including the electrode A is formed.
In this method, an insulating layer 50b having corrosion resistance to the etching solution is formed so as to uniformly cover the surface of No. 1 and then the low melting point glass layer 29c is formed.

[0019]

The exposed surface of the low-melting glass layer 29c is covered with a corrosion prevention film 71 made of an oil agent via a surfactant 80. However, the end surface S in the thickness direction of the low melting point glass layer 29c
When an etching solution is sprayed on the substrate 1 at a suitable pressure, the corrosion preventing film 71 on the end face S1 is broken and disappears due to the impact force, and only the side surface having a weak impact force is covered with the corrosion preventing film 71. Thus, the etching proceeds only in the direction in which the etching solution is sprayed, and becomes anisotropic etching in the thickness direction of the low-melting glass layer 29c.

[0020]

1 is a cross-sectional view showing the structure of a main part of a PDP 1 according to the present invention, FIG. 2 is a cross-sectional view showing each state of the PDP shown in FIG. 1 at a manufacturing stage, and FIG. FIG. In these drawings, components corresponding to those in FIG. 4 are denoted by the same reference numerals regardless of differences in shape and dimensions.

In FIG. 1, a PDP 1 is a surface discharge type PDP having a three-electrode structure called a reflection type, and comprises a display electrode comprising a glass substrate 11 on a display surface side, a transparent conductive film 41 and a bus metal layer 42 overlapping therewith. X, Y, the dielectric layer 17 covering the display electrodes X, Y, the MgO film 18, the glass substrate 21 on the back side, the address electrodes A orthogonal to the display electrodes X, Y, and the stripe defining the gap size of the discharge space 30 Partition wall 2
9 and a phosphor 28 of a predetermined emission color.

The partition walls 29 are arranged between the address electrodes A so as to partition the discharge space 30 in the line direction for each unit light emitting area EU. The width of each partition 29 is about 50 μm, and the interval between each partition 29 is about 100 μm.
That is, the size of the unit light emitting region EU in the line direction (the partition 2
9 is about 150 μm.

The PDP 1 is structurally different from the PDP 10 of FIG. 4 in that the partition 29 is formed on an insulating layer 50 covering the address electrode A. The provision of the insulating layer 50 facilitates formation of the partition 29 by a photolithography method as described later. Note that the thickness of the insulating layer 50 on the address electrode A is sufficiently smaller than the gap size of the discharge space 30, so that there is no trouble in the selective discharge.

As shown in FIG. 2, when manufacturing the PDP 1 on the glass substrate 21 side, 5 to 30 μm
After forming the address electrode A having a thickness of about 15 μm, a low-melting glass paste 50a is applied to a thickness of about 15 to 40 μm so as to uniformly cover the surface of the glass substrate 21 including the address electrode A [FIG. (A)]. At this time, as the low melting point glass paste 50a, for example, a paste containing less PbO component and more SiO ₂ component than the paste of the dielectric layer 17 is used.

Next, a low-melting glass paste 29a for a partition wall is applied to the entire surface of the paste layer 50b obtained by drying the low-melting glass paste 50a to a thickness of, for example, about 180 to 200 μm (FIG. 2B). ]. Paste 29
As a, a paste containing glass powder having a composition different from that of the paste layer 50b is used. In addition, as a coating method, a screen printing method, a bar coater method, an applicator method, or the like can be used.

Subsequently, the solid film made of the paste 29a is fired together with the paste layer 50b to form an insulating layer 50 and a low-melting glass layer 29c having a thickness of about 130 to 150 μm covering the insulating layer 50 on the glass substrate 21. Thereafter, a photosensitive resin is applied by a roll coater method or the like, and pattern exposure and development are performed to provide a resist layer 61 having a predetermined pattern with a thickness of about 5 μm on the low melting point glass layer 29c [FIG.
(C)].

Then, using the resist layer 61 as an etching mask, the low-melting glass layer 29c is patterned by a wet etching method to form the partition wall 29 having the above-described dimensions.
Is formed (FIG. 3D).

At this time, as an etching solution, an etchant (nitric acid) having selectivity to the insulating layer 50 and the low-melting glass layer 29c, an oil agent such as diethylbenzene or sulfated castor oil, and a rheodol (Kao Corporation) A solution in which a surfactant such as (trade name) is mixed is used. Then, as shown in FIG. 3A, such an etching solution is sprayed, for example, from below on the end surface S1 in the thickness direction of the low melting point glass layer 29c.

Since the etchant has selectivity, the insulating layer 50 becomes a protective layer (buffer layer) for the address electrode A, and the etching time is set longer to completely remove the unnecessary low melting point glass layer 29c. Also, since the address electrode A is not affected, the partition wall 29 having a predetermined height can be easily obtained.

The anisotropic etching can be performed on the low-melting glass layer 29c by spraying an etching solution in which an oil agent and a surfactant are mixed on the surface to be etched.

That is, when the surface of the low-melting glass layer 29c provided with the resist layer 61 is immersed in an etching solution, corrosion (melting) by the etchant starts gradually from the surface of the low-melting glass layer 29c, and at the same time. As shown in FIG. 3B, the low-melting glass layer 29c is formed by the action of promoting the film formation of the surfactant 80 comprising the lipophilic group 81 and the hydrophilic group 82.
A corrosion prevention film 71 made of an oil agent is formed so as to cover the exposed surface of.

Since the corrosion prevention film 71 is also formed on the end face S1, the etching is stopped by the corrosion prevention film 71 simply by immersing the low-melting glass layer 29c in the etching solution. However, when the etching solution is sprayed on the end face S1 with an appropriate pressure, the corrosion preventing film 71 on the end face S1 is broken by the impact force and disappears, and the low melting point glass layer 29c is formed.
Is covered with the corrosion prevention film 71 only on the side surface (lateral end surface) S2 of the exposed surface in FIG. For this reason, etching mainly proceeds in the direction of spraying the etching solution,
Anisotropic etching in the thickness direction of the low melting point glass layer 29c is performed.

The spraying of the etching solution is performed using a shower type or paddle type etching apparatus, and at this time, the glass substrate 21 is arranged with the end face S1 facing downward.

After the partition walls 29 are formed in this manner, the phosphors 28 are provided between the partition walls 29, and the glass substrate 21 and the glass substrate 11 provided with separate display electrodes X and Y are superposed. To complete PDP1.

According to the above-described embodiment, the etching solution is sprayed from below, so that the etching solution does not accumulate in the cavities formed by etching as in the case of spraying from above. For this reason, since the contact state between the surface to be etched and the etching solution is almost constant and there is no change in the etching rate, the setting of the etching time becomes easy and the lateral direction of the etching solution causing the side etching becomes easy. Flow can be reduced.

According to the above-described embodiment, since the address electrode A is covered with the insulating layer 50, the address electrode A is not corroded by nitric acid as an etchant when patterning the low-melting glass layer 29c serving as the partition wall 29. Therefore, by setting the etching time longer, the unnecessary low melting point glass layer 29 can be completely removed over the entire display surface H, and the shape of the partition wall 29 can be made uniform even in the case of a large screen. it can.

According to the above-described embodiment, the positional accuracy of the partition wall 29 can be improved and the shape can be made uniform as compared with the case where the partition wall 29 is formed by pattern printing by the screen printing method.

In the above-described embodiment, the etching conditions such as the material and mixing ratio of each of the three kinds of liquids (etchant, oil agent, surfactant) constituting the etching solution, and the spray pressure are determined by the material of the partition wall 29. And the size may be optimized. Further, by using an in-line type etching apparatus, the efficiency of the partition wall forming step can be improved.

In the above embodiment, the low melting glass paste layer 50b and the low melting glass paste 29a applied thereon are simultaneously fired to form the insulating layer 50 and the low melting glass layer 29c. , Insulating layer 50
After the formation, a low-melting glass paste 29a may be applied and fired.

[0040]

According to the present invention, a high definition plasma display panel can be easily manufactured.

According to the second aspect of the invention, side etching due to the lateral flow of the etching solution can be suppressed, and higher definition can be achieved. According to the invention of claim 3,
Even in the case of a large screen, the shape of the partition can be made uniform.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of a main part of a PDP according to the present invention.

FIG. 2 is a cross-sectional view showing each state of the PDP of FIG. 1 at a manufacturing stage.

FIG. 3 is a cross-sectional view showing the progress of etching.

FIG. 4 is an exploded perspective view of a general surface discharge type PDP.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 PDP (plasma display panel) 21 Glass substrate (substrate) 29 Partition wall 29c Low melting glass layer 30 Discharge space 50b Low melting glass paste layer (insulating layer) 61 Resist layer (etching mask) 71 Corrosion prevention film 80 Surfactant A Address Electrode (electrode) EU unit light emitting area S1 end face

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-248338 (JP, A) JP-A-4-123744 (JP, A) JP-A-1-251534 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H01J 9/02 H01J 11/02

Claims (3)

(57) [Claims] 1. A discharge space (30) is defined as a unit light emitting area (EU).
A method for manufacturing a plasma display panel (1) having partition walls (29) partitioned into respective sections, comprising a low-melting glass layer (29) having a uniform thickness on a substrate (21).
forming an etching mask (61) that partially covers the low-melting glass layer (29c) by applying a photosensitive resist material and pattern exposure; and forming the low-melting glass layer (29c). ), An etching solution containing a mixture of an etchant that corrodes, an oily agent that forms a corrosion prevention film (71), and a surfactant (80) that facilitates the formation of the corrosion prevention film (71) is mixed with the low melting glass layer ( 29
c) is sprayed on the end surface (S1) in the thickness direction to partially remove the low-melting glass layer (29c) to remove the partition wall (2).
9. A method of manufacturing a plasma display panel, comprising the steps of: 2. The substrate (21) is disposed with the end surface (S1), which is the surface to be etched, facing downward.
2. The method according to claim 1, wherein the etching solution is sprayed from below on 1). 3. An electrode (A) is formed on said substrate (21), and has a corrosion resistance to said etching solution so as to uniformly cover the surface of said substrate (21) including said electrode (A). The method for manufacturing a plasma display panel according to claim 1, wherein an insulating layer (50b) having the following is formed, and then the low melting point glass layer (29c) is formed.