JP2741418B2 - Metal core rib, method of manufacturing the same, and plasma display panel using the metal core rib - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a metal core rib (perforated metal plate) whose surface is covered with a dielectric, and a plasma display panel using the metal core rib as a partition wall or a spacer.

[Prior Art] Generally, in a plasma display panel (hereinafter abbreviated as PDP) in which a plurality of discharge cells are arranged, an appropriate discharge gap is ensured regardless of a discharge type such as AC or DC, or an adjacent cell is used. In order to prevent crosstalk, a dielectric called a partition or a spacer is required.

By the way, the arrangement of the discharge cells of the PDP is determined according to the purpose of use.
There are 7-dot character display, 640 × 480 full-dot display, and the like.

1 to 5 show examples of the arrangement of the discharge cells of these PDPs. 1 to 5, reference numeral 1 denotes a front glass plate, 3
Denotes a partition, and 4 denotes a back glass plate. As shown in these figures, partition walls and spacers having cell holes of various shapes and arrangements are used. The partition can be formed by the same method for any cell arrangement, and various methods have been tried so far, for example, as shown below.

Method A: Thick film method (multilayer printing of screen printing) Method B: Etching of photosensitive plate glass Method C: Drilling of plate glass [Problems to be Solved by the Invention] Among them, Method A is inexpensive and excellent in mass productivity. However, there is a disadvantage that a sufficient discharge gap cannot be obtained unless printing is repeated many times. Also, especially full dot display
In PDPs, high definition of dot pitch (for example, 0.2 mm dot pitch) is an important issue, but screen printing is difficult to deal with. There is an example realized with the stripe shape as shown in FIG. 2 (Y. Amano: SID Int. Symp. Di).
g.Tech.Paper.p.169 (1982)), as shown in Figs. 1 and 4, it is particularly difficult to deal with partition walls that completely surround the discharge cell from the surroundings, and very advanced technology is required. And not practical.

By the way, when there is a portion where a partition does not exist between adjacent cells even in one direction, such as a partition (hereinafter, referred to as a completely closed partition) completely surrounding the discharge cell and a stripe shape (hereinafter, an incompletely closed partition). There is a big difference in the following sense.

For example, a PD that emits orange light due to the discharge of neon gas
When the emission color of the rare gas itself is used, as in P, the emission is limited only to the vicinity of the electrode of the selected cell. When thinking, in order to take the method of exciting and emitting the phosphor by ultraviolet rays accompanying the discharge,
In the imperfectly closed partition, the leakage of the ultraviolet rays may cause the phosphors in the adjacent cells to emit light by excitation. That is, crosstalk or color blur is inevitable, color reproducibility and resolution are impaired, and the value as a display is reduced. In that respect, the method A is not suitable for producing a high-definition completely closed partition wall, and is not practical for a color PDP.

The B method is considered to be relatively easy to cope with high definition, but is expensive because of using a very special photosensitive glass as a material, and is inferior in economical efficiency. Further, it is practically difficult to assemble a thin glass plate having a thickness of 0.1 to 0.5 mm because the glass is brittle.

Regarding the method C, although general glass can be used, it is difficult to form a hole with a high-definition cell pitch, and assembling is also difficult.

Therefore, in the related art, partition walls and spacers that can cope with higher definition of the PDP, secure an appropriate discharge space, and are relatively inexpensive and excellent in mass production have not been found yet.

An object of the present invention is to provide a metal core rib used as a partition wall or a spacer which is relatively inexpensive and excellent in mass productivity in view of the problems of the related art, and ultimately has a high definition. It is intended to provide a PDP which can secure a suitable discharge space.

[Means for Solving the Problems] The above object of the present invention is achieved by using a metal core rib, the surface of which is coated with a dielectric, as a partition or spacer of a PDP.

That is, the metal core ribs used for the partition walls or spacers of the PDP of the present invention have a thickness of 1 mm including glass on the upper and lower surfaces and the inner surface of the metal plate on which a large number of through holes are arranged.
A metal plate densely covered with a dielectric material having a thickness of 100100 μm, a linear thermal expansion coefficient of the metal plate is 80 to 100 × 10 ⁻⁷ / ° C., and an aperture ratio of a region where the holes are arranged is 42 % Or more.

 Hereinafter, the present invention will be described in more detail.

In the present invention, the base metal used as a partition or spacer of the PDP and serving as a base of a metal core rib whose surface is coated with a dielectric material is 42 wt% Ni-6 wt% Cr
-Fe alloy, 50% by weight Ni-Fe alloy, and the like. The thickness of these metal plates is preferably about 0.05 to 1.0 mm.

By the way, the partition wall and the spacer are sandwiched between two glass plates, and the periphery thereof is sealed with sealing glass in order to enclose gas therein. Therefore, the linear thermal expansion coefficients of the partition wall (spacer), the two glass plates, and the sealing glass must be substantially the same or similar. Otherwise, during the cooling process after sealing, the glass will be over-stressed and will break.

In general, soda-lime glass is generally used for the two glass plates. Therefore, the linear thermal expansion coefficient of the metal core rib of the present invention is 80 to 100 (× 10 ⁻⁷ / ° C.) in accordance with this. Therefore, as described above, a base metal such as a 42 wt% Ni-6 wt% Cr-Fe alloy is used. Of course, when using a glass member having a different linear thermal expansion coefficient from that described above, the material of the partition may be selected according to this.

As a method for forming a predetermined hole in the metal plate, a punching method using a press, a laser processing method, an etching method, or the like can be used. The most advantageous processing method may be used in consideration of processing distortion, processing accuracy, processing cost, and the like, but generally, an etching method is preferably used.

The shapes and arrangements of the punched holes of the metal core ribs are arbitrary, and examples thereof include a lattice shape, a line shape, a circle, a delta type, and a seven-segment type shown in FIGS.
In the present invention, the shape which becomes a high-definition completely closed partition shown in FIGS. 1 and 4 is preferable, and the lattice shape shown in FIG. 1 is particularly preferable.

The metal core rib of the present invention has a surface of 1 to 100 μm
Of dielectric material is applied.

The dielectric used here includes glass.
More specifically, glass or a crystalline inorganic material containing glass is generally used.

Taking specific glass composition in examples, PbO-B ₂ O ₃ -SiO
_{2, PbO-B 2 O 3} , ZnO-B 2 O 3 -SiO 2 and the like. The softening point of these glasses is 350-1000 ° C, and the particle size of the glass is 1-5.
Each is preferably about μm. This glass is heated to a temperature at which the sealing glass frit softens and melts (sealing temperature) in the sealing process of the PDP. The sealing temperature of ordinary glass frit is about 50 ° C. higher than the softening point, and the sealing temperature of PDP is about 400 to 450 ° C., therefore, the softening point of glass contained in the dielectric material is 350 ° C. It is desirable that this is the case. The upper limit of the softening point is determined on the condition that the base metal does not deform and the base metal and the dielectric do not cause a chemical reaction, and the temperature is desirably 1000 ° C. or lower.

Ceramics such as alumina (Al ₂ O ₃ ) and forsterite (2MgO—SiO ₂ ) are used as crystalline inorganic substances, and inorganic pigments (FeO—Cr ₂ O ₃ , CoO—Al ₂ O _3, etc.)
Can also be used. The particle size of this crystalline inorganic substance is 1
About 5 μm is preferable.

Any organic substance can be used as long as it can be finally mineralized.

Depositing a dielectric made of such a material is performed by PD
This is because the characteristics of the surface of the partition wall exposed to the discharge space are important because the partition walls of P play a role of independently separating the discharge cells arranged in a matrix. That is, if only the base metal without the dielectric is applied, an electric short circuit occurs between the adjacent cells and does not serve as a partition.

In addition, it is necessary that the dielectric is used in the discharge space, does not cause alteration and deformation, does not contaminate the discharge gas space, and has good adhesion to the base metal without any gap for exposing the base metal to the discharge space. It is. Further, in a general panel sealing method (sealing with sealing glass), it must withstand the sealing temperature and have a coefficient of linear thermal expansion substantially equal to that of two glass plates, sealing glass, and base metal.

From such a viewpoint, the above materials are appropriately selected.

Further, as a method for forming a dielectric film on the metal core rib surface in the present invention, at least one or more of the following methods can be used.

That is, (1) a dipping method in which a dielectric powder is melted or a liquid in which the dielectric powder is dissolved or dispersed in water or an organic solvent, (2) a spray method in which the liquid is applied in a spray form, (3) firing oxidation method in which a base metal is fired and oxidized in an appropriate atmosphere to form a metal oxide film on the surface; and (4) oxide film is formed on the metal surface in a suitable electrolyte using the base metal as an anode. Anodizing method,
(5) an electrostatic coating method using high-voltage static electricity, and (6)
By dispersing the dielectric powder in a liquid, the dielectric particles are charged either positively or negatively. Using the base metal as the cathode or anode, the charged particles (dielectric particles) are placed on the metal surface. There is an electrodeposition method of attracting and depositing.

Among these, the most advantageous method may be used in consideration of the uniformity of the coating, the formed thickness, the ease of controlling the forming conditions, the influence on the base metal, and the like, but the electrodeposition method is most used. good.

According to this electrodeposition method, the thickness of the deposited film is very uniform, a thickness of about 100 μm can be deposited, the thickness can be easily controlled, and the deposited film can be deposited in a short time. Another advantage is that two or more dielectrics can be co-precipitated and the mixing ratio can be arbitrarily selected.

After electrodeposition of the dielectric material on the surface of the metal core rib, firing is performed at a predetermined temperature. The atmosphere at the time of firing can be set in the air, in an inert gas, in a vacuum (under reduced pressure), etc. in consideration of the properties of the organic binder used. Is preferred.

When the panel of the present invention is formed by sandwiching a metal core rib whose surface is coated with a dielectric material as a partition wall between two sheets of glass as it is, there is no gap between the cells surrounded by the grid and gas spreads to all cells. No result. Therefore, it is necessary to form a groove on one or both surfaces of the metal core rib (partition wall), or on at least one of the two glass sheets to form a gas introduction hole. Or a partition and 2
It is also possible to secure a gas introduction hole by inserting a spacer so as to have a slight gap between the sheet glasses.

[Operation] The present invention has a disadvantage that, when forming a fine lattice-like dielectric or the like, a dielectric (glass or an inorganic material containing glass or the like) alone is inferior in workability and assembly workability. In view of the above, a desired material is provided by combining a dielectric material with a metal material having excellent workability and assembly workability.

Therefore, restrictions on the shape, such as the hole size, shape, or array pitch, largely depend on the processing accuracy of the base metal.
Has sufficient accuracy to form the dot size and dot pitch required in the above. Further, since the base is made of metal, the metal core rib of the present invention whose surface is coated with a dielectric does not have the brittleness seen in a thin glass plate, has flexibility, and is excellent in assembling workability.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 As a metal plate serving as a base, a coefficient of linear thermal expansion was 92 (× 10 ^−7).
/ ° C) of 42 wt% Ni-6 wt% Cr-Fe alloy. Metal plate thickness is 0.1mm, dot pitch is 0.2 for both vertical and horizontal
mm, the hole size was 0.15 × 0.15 mm, and a large number of holes were formed by etching to form a lattice-shaped metal core rib.

As the dielectric material, a softening point of 600 ° C. and an average particle diameter of 2-3
ZnO-B ₂ O ₃ -SiO ₂ based glass powder and Al ₂ O ₃ of [mu] m, FeO
· Cr ₂ using an inorganic filler O ₃ or the like. The dielectric was deposited in an electrodeposition solution having a composition as shown in Table 1 using a grid-shaped metal core rib as a cathode and a metal plate of the same material and the same area as an anode as an anode. . Working voltage is DC 200
The bolt was fixed.

As a result, the electrodeposition state and the electrodeposition layer strength were also very good.

This sample is softened at 600 ° C in glass atmosphere
By firing at a higher temperature, the dielectric layer was made into a dense film, and a desired lattice-shaped metal core rib whose surface was covered with a dielectric was obtained.

Next, a DC-PDP using the grid-shaped metal core ribs whose surfaces were covered with a dielectric as a partition was prepared as shown below.

That is, as shown in FIGS. 6 to 9, grid-like metal core ribs whose surfaces are covered with a dielectric were used as the partition walls 3, and glass about 30 μm thicker than the partition walls 3 was used as the spacer 2. The partition wall 3 and the spacer 2 are sandwiched between two front glass plates 1 and rear glass plates 4 on which electrodes are formed in advance, and the periphery thereof is sealed with a sealing glass 5 to form an XY matrix DC-PDP. Was formed.

The sealing condition of this DC-PDP was good, and no problems such as breakage due to stress strain occurred. At this time, the spacer is PDP
In the display area having the partition walls, a gas introduction space of about 30 μm was always present, and the exhaust and gas filling in the tube could be reliably performed over the entire display area.

Examples 2 to 7 Using the same grid-shaped metal core ribs as in Example 1, electrodeposition was performed in an electrodeposition solution having a composition shown in Table 1 under the same electrodeposition conditions.

As a result, the electrodeposition time was 5 minutes in each case, and an electrodeposited layer having a thickness as shown in Table 1 was obtained. In addition, the electrodeposition state was good in all cases, but in Example 7, since the organic binder was not added to the electrodeposition solution, the electrodeposition layer strength was weak, and the electrodeposition layer was easily peeled off. In such cases, care must be taken in handling.

These samples were subjected to a softening point of 60
By firing at a temperature higher than 0 ° C., the dielectric layer was made into a dense film, and a lattice-shaped metal core rib having a desired surface covered with a dielectric was obtained.

Next, when a DC-PDP was prepared in the same manner as in Example 1 using the lattice-shaped metal core ribs as the partition walls, the sealing condition was good, and the in-pipe exhaust and gas sealing could be performed well.

Comparative Example 1 The partition walls of the DC-PDP shown in Example 1 were formed by thick film printing.

First, the formed dot pitch is 1.0mm, and the hole size is 0.8 × 0.
An 8 mm partition was made. The height of the partition walls could be formed to be 0.15 mm by eight times of overprinting.

Next, an attempt was made to form a partition having a dot pitch of 0.2 mm and a hole size of 0.15 × 0.15 mm with the same precision as that shown in Example 1. At a pitch of 1.0 mm, subtle misalignment that could be almost ignored or dripping of the printing paste could not be ignored, manufacturing was technically difficult, and the yield was much worse than in Example 1. In addition, a well-manufactured product could not obtain a sufficient cell opening ratio for the above-described reason. As an example, the hole size was 0.1 × 0.1 mm and the aperture ratio was 25% with respect to the pitch of 0.2 mm. In Example 1 described above, since the deposited dielectric layer was 10 μm, the hole size was 0.13 × 0.13 mm and the aperture ratio was 42%. Thus, Example 1 was clearly advantageous.

Comparative Example 2 The partition wall of the DC-PDP shown in Example 1 was formed by etching a photosensitive plate glass. However, as described above, this material is extremely expensive in terms of price, and is very brittle because it is a thin sheet glass.
Was worse.

Comparative Example 3 A common soda-lime glass or the like was perforated to form a DC-PDP partition as in Comparative Example 2. However, when a large number of holes are drilled with a fine pitch of about 0.2 mm by this method, the dimensional accuracy is considerably reduced as compared with Comparative Example 2. Also, considering the brittleness of the thin glass, the workability and the assembly workability were inferior to Comparative Example 2 and therefore considerably inferior to Example 1.

Comparative Example 4 A metal core rib used as a substrate and not covered with a dielectric was used alone as a partition. As a result, an electric short circuit occurs between the anode and the cathode and the lamp does not light up, or in some cases, only the anodes or only the cathodes are short-circuited, causing a disadvantage that an unselected cell emits light,
It didn't make sense as a PDP bulkhead.

[Effects of the Invention] As described above, by using the metal core ribs whose surfaces are coated with a dielectric material for the partition walls and spacers of the PDP, it is possible to cope with a high-definition cell pitch and to have excellent crosstalk characteristics. Moreover, an appropriate discharge space can be secured.

[Brief description of the drawings]

FIG. 1 is an example of a PDP using lattice-shaped partitions in an XY matrix matrix, FIG. 2 is an example of a PDP using line-shaped partitions in an XY matrix matrix, FIG. FIG. 4 shows an example of a PDP using a delta-arranged partition wall, FIG. 5 shows an example of a PDP using a 7-segment type partition wall, FIG. Is a PDP component part and its assembly process, FIG. 7 is a plan view after assembling the PDP, FIG. 8 is a vertical sectional view when the AA ′ section of FIG. 7 cuts through the cell space, and Fig. 9 is a vertical cross-sectional view when the AA 'cross section of Fig. 7 cuts a partition wall. 1: front glass plate, 2: spacer, 3: partition wall (metal core rib whose surface is covered with a dielectric), 4: rear glass plate, 5: sealing glass.

Continued on the front page (72) Inventor Tatsumasa Yokoi 74, Nakamichi, Utasu-zai, Hachikai-mura, Kaifu-gun, Aichi Prefecture (72) Inventor Hideyuki Asai 5 Nakaike, Nagakute-cho, Nagakute-cho, Aichi-gun, Aichi Prefecture 5 (56) References JP-A-55-143754 (JP, A) JP-A-60-103050 (JP, A) JP-A-1-120731 (JP, A) JP-B-45-18618 (JP, B1)

Claims (2)

(57) [Claims] An upper and lower surface and an inner surface of a metal plate on which a large number of through holes are arranged are densely covered with a dielectric material containing glass and having a thickness of 1 to 100 μm. A metal core rib for a partition or a spacer, wherein a coefficient of thermal expansion is 80 to 100 × 10 ⁻⁷ / ° C., and an aperture ratio of a region where the holes are arranged is 42% or more. 2. A plasma display panel using the metal core rib according to claim 1 as a partition or a spacer.