WO2009070997A1

WO2009070997A1 - Plasma display panel with fluorescent layer printed on shadow-mask

Info

Publication number: WO2009070997A1
Application number: PCT/CN2008/071862
Authority: WO
Inventors: Kai Liu; Zhaowen Fan; Xiong Zhang; Lifeng Zhu; Baoping Wang; Qingyuan Lin; Gang Chen
Original assignee: Nanjing Huaxian High Technology Co., Ltd.
Priority date: 2007-11-26
Filing date: 2008-08-04
Publication date: 2009-06-11

Abstract

A shadow-mask plasma display panel comprises a front panel (9), a back panel (10) and a shadow-mask (11) interposed between the front panel (9) and the back panel (10), the front panel (9) comprises a front glass substrate (1), an electrode group (2), a dielectric layer (3) and a protective film (4), the back panel (10) comprises a back glass substrate (5), an electrode group (6), a dielectric layer (7) and a protective film (8), the shadow-mask (11) is a thin metal plate with micro-hole (12) array, wherein a fluorescent layer is applied on the inner wall of the micro-hole (12) by screen-printing. The mask opening (16) for printing has an annular pattern or a cruciform annular with concaved sides. The shadow-mask (11) is fixed by the magnetic force and vacuum. The fluorescent slurry comprises 40~50% fluorescent powder, 3~6% organic resin, 45~55% organic solvent and 0.5~3% nano-powder.

Description

Instruction manual

Shadow mask plasma display panel for phosphor printing

The invention relates to a plasma display technology, in particular to a shadow mask type plasma display panel which uses a printing method to form a phosphor on a shadow mask, in particular, a fluorescent film for a shadow mask type plasma display panel. Powder slurry and method of forming on a shadow mask. Background technique

Currently, the shadow mask plasma display (SMPDP) is a new type of opposed discharge type AC plasma display panel. In the manufacturing process, the shadow mask (metal grid) commonly used in color CRT production is used to replace the complex barrier manufacturing in the PDP, the metal grid is processed independently, and the phosphor is fabricated thereon, and finally the front substrate, The metal grid plate and the rear substrate are assembled in a "sandwich" manner to make a full screen, as shown in FIG. The discharge unit is composed of three shadow mask holes 12 on the metal grid plate 11, and the three color phosphors of R, G and B are sequentially coated in the shadow mask holes, as shown in Fig. ,, the phosphor is completely coated. Applying to the side wall and bottom of the shadow mask hole, it can not flow out of the shadow mask hole, blocking the small hole in the shadow mask, affecting the discharge.

The phosphor of the shadow mask type monochrome or color plasma display panel is prepared by a spray coating technique. Spraying technology is widely used in printing, construction, automobile manufacturing and other industries, and the process is mature. However, in the preparation of phosphor powder for shadow mask plasma display panels, there are still many problems that need to be solved urgently. First, the phosphor of the shadow mask type plasma display panel needs to be sprayed in each of the micropores on the shadow mask, the micropores are in the shape of a bowl, and the inner wall is rough, and the phosphor is in the form of particles, so that the shadow mask is required to be microscopically It is difficult to obtain a dense and relatively thick powder layer on the inner wall of the hole, and the spraying process is difficult. As the resolution increases, the micropore has a smaller spatial size and is more difficult to apply. Secondly, the preparation of the phosphor by spraying requires an additional mask mask to block the phosphors of other colors when the red, green and blue phosphors are sprayed. Therefore, the arrangement of the micropores on the shadow mask is the same as that of the working shadow mask, but the number of micropores is 1/3 of the working shadow mask. In the phosphor preparation process, the mask mask is worn out, so the cost of the shadow mask is increased. Third, the working shadow mask functions to block the crosstalk of adjacent cells and carry the phosphor in the plasma display panel, and thus must be designed in the shape of a bowl, that is, the opening on one side is large, and the opening on the other side is small. This inevitably leads to uneven stress on the two surfaces of the shadow mask, which is manifested by partial warpage. Although the mask shadow mask can ensure the stress balance of the two surfaces, the number of openings is significantly smaller than that of the working shadow mask, and the strength is high, so the physical properties of the two shadow masks are different. When spraying, the two kinds of shadow masks need to be closely attached and fixed, and the magnetic plate adsorption method is currently used. Because of the difference in the physical properties of the two kinds of shadow masks, that is, the magnetic sheets with strong magnetic properties are used to adsorb the two, it is difficult to make the edges of the shadow mask adsorb tightly, and there is a gap between the mask mask and the working shadow mask at the edge. Easy to spray when spraying This is a cross-color, which is particularly prominent in large-area shadow masks. In a monochrome shadow mask type plasma display panel, edge brightness unevenness occurs. In the color shadow mask type plasma display panel, the edge color is found to be impure, resulting in waste. Fourth, when spraying, the mask mask is placed in front of the working mask because it blocks the other two kinds of micropores on the working mask. Because of this, only 30% of the phosphor is sprayed onto the surface of the mask. It enters the micro-hole of the working shadow mask, and the other 70% is covered on the mask shadow mask. If this phosphor is not effectively recycled and reused, it will cause huge waste.

The problems in the above phosphor coating technology plague the improvement of the quality of the shadow mask plasma display panel. Summary of the invention

The object of the present invention is to solve the problems of high cost, easy cross-coloring and high process difficulty when the phosphor powder is formed by the spraying method of the conventional display panel, and provides a fluorescent shadow printing on the shadow mask which is convenient to manufacture and has good effect. Shadow mask plasma display panel.

The technical solution of the present invention is:

A shadow mask plasma display panel formed by phosphor printing on a shadow mask, comprising a front panel 9, a rear panel 10, and a shadow mask 11 sandwiched between the front and rear panels, the front panel 9 comprising a front substrate glass substrate 1. Electrode group 2, dielectric layer 3 and protective film 4, electrode group 2 is located between glass substrate 1 and dielectric layer 3, protective film 4 covers the surface of dielectric layer 3, and rear plate 10 includes rear substrate glass substrate 5, the electrode group 6, the dielectric layer 7, the protective film 8, the electrode group 6 is located between the glass substrate 5 and the dielectric layer 7, the protective film 8 is located on the surface of the dielectric layer 7, the shadow mask 11 is an array comprising micro holes 12 The metal foil is provided with a phosphor layer on the inner wall of the micropores 12, wherein the phosphor layer is shaped in the micropores 12 by screen printing.

The micropores 12 are printed and formed into three colors of red 13, green 14, and blue 15 phosphors according to a specific arrangement rule.

The phosphors are all red phosphors 13, all of which are green phosphors 14 or all of them are blue phosphors 15.

The micropores 12 on the shadow mask 11 are arranged in a strip shape or arranged in a "shape" shape. The screen printing pattern formed by the phosphor printing on the shadow mask is characterized in that the screen hole (16) is designed to correspond to all the holes in the shadow mask according to the arrangement of the shadow mask holes in the SMPDP. Color PDP phosphor printing screen; can also be designed as a three-color PDP phosphor printing screen corresponding to a single color hole on the shadow mask, the number of screen holes (16) is 1 of the number of shadow mask holes /3. In addition, the wire mesh hole (16) can also be designed as a four-sided concave cross ring (17) to avoid color mixing due to a certain size deviation during alignment.

The phosphor paste used in the present invention is characterized in that it is composed of a phosphor, an organic resin, an organic solvent and a nano powder, wherein the phosphor accounts for 40 to 50% of the total weight, and the organic resin accounts for 3 to 6% of the total weight. 5〜3%。 The total weight of the total weight of 0. 5~3%. Wherein the organic resin is ethyl cellulose, the The organic solvent is terpineol, and the nano powder is Si0 ₂ , A1 ₂ 0 ₃ or Ti0 ₂ , and the phosphors are respectively one of the three primary color phosphors.

In addition, before the shadow printing machine 11 of the present invention is printed on the upper printing machine, the shadow mask 11 should first be placed by a magnetic adsorption method or a pasting method with a surface roughness of between Ra0.32-2.5 and a flatness of between 0.2-2. On a flat medium (soft magnetic board, etc.), the flat medium is then mounted on a printing table of a screen printing machine and fixed by vacuum fixing to perform printing.

The monochromatic phosphor paste is printed on the shadow mask by screen printing. After printing, it is observed under the microscope. The phosphor paste in the shadow mask hole has no bubbles, the printing is full, no unprinted, no blocking hole Then, the shadow mask is directly placed in a drying oven at a temperature of 150 ° C to 170 ° C for drying for 10 to 15 minutes. The purpose is to quickly dry the slurry to avoid viscosity due to slow drying of the slurry. Dropping and flowing into the small hole of the shadow mask causes the hole to be blocked. After drying, the phosphor film layer is observed under the microscope, and the phosphor film layer is evenly attached to the hole wall and the bottom of the shadow mask, without large particles or powder clusters, Empty, no plugging; finally put the shadow mask into the sintering furnace for sintering, control the sintering temperature is 430 ° C ~ 500 ° C, the time is 25 ~ 35min, after sintering, placed under the microscope, the phosphor layer White, delicate, no large powder, no void, no blocking is qualified; repeat the above steps to complete the production of the phosphor layers of the three primary colors.

The beneficial effects of the invention:

The invention can be used for phosphor powder forming by adopting a relatively mature screen printing process, which can greatly reduce the manufacturing process difficulty of the display panel; at the same time, through reasonable design of the screen pattern and the optimization of the screen printing process parameters, it can be obtained. The color silk screen effect; and through the preparation of a reasonable phosphor slurry, the phosphor dispersion, stability, thixotropy and phosphor adhesion in the slurry can be improved, and a high-quality phosphor film layer can be obtained, which is greatly improved. The quality of the display panel; in addition, the utilization of the phosphor can be improved, the waste of the phosphor is reduced, and the utilization rate of the phosphor slurry is more than 90%. DRAWINGS

1 is a schematic view showing the structure of a shadow mask type plasma display panel of the present invention.

Fig. 2 is a schematic view showing the structure of the shadow mask microholes arranged in a strip shape.

Fig. 3 is a structural schematic view of the micro-holes of the shadow mask arranged in a "good" shape.

Fig. 4 is a schematic view showing the structure in which the micro-holes of the shadow mask have a rhombic structure and are arranged in a "product" shape.

Fig. 5 is a schematic view showing the arrangement of the mesh holes and the mesh hole shape thereof in the present invention.

Fig. 6 is a schematic view showing another mesh hole pattern in the present invention.

Figure 7 is a schematic cross-sectional view of the micro-hole of the shadow mask. detailed description

The invention will now be further described with reference to the accompanying drawings and embodiments. As shown in Figure 1-7.

A shadow mask plasma display panel based on a phosphor printed on a shadow mask, comprising a front panel 9, a rear panel 10, and a shadow mask 11 sandwiched between the front and rear panels. The front plate includes a front substrate glass substrate 1, an electrode group 2, a dielectric layer 3, and a protective film 4, the electrode group 2 is located between the glass substrate 1 and the dielectric layer 3, and the protective film 4 covers the surface of the dielectric layer 3. . The rear plate includes a rear substrate glass substrate 5, an electrode group 6, a dielectric layer 7, a protective film 8, an electrode group 6 between the glass substrate 5 and the dielectric layer 7, and a protective film 8 on the surface of the dielectric layer 7. The shadow mask 11 is a thin metal plate containing an array of micro holes 12.

In a specific implementation, the phosphors covered in the micro-holes 12 of the shadow mask are sequentially printed in the order of the blue phosphors 15, the green phosphors 14, and the red phosphors 13. In the specific preparation, the phosphor powder of the three primary colors may be prepared first, and the screen printing may be performed in the order of printing, and the printing may be performed in the order described above or in other color sequences.

In the specific implementation, the shadow mask micropores 12 may be arranged in a strip shape or in a "product" shape. Specific implementation

First, a blue phosphor slurry is prepared and made on the shadow mask 11:

3 g of organic resin ethyl cellulose, 2 g of SiO^fi rice powder and 45 g of organic solvent terpineol were mixed well, and an organic carrier was prepared under stirring in a water bath, and 50 g of blue phosphor particles were sufficiently dispersed. Among them, a blue phosphor slurry was formed.

Before printing, the shadow mask 11 is first placed on a flat medium (soft magnetic board, etc.) having a surface roughness of Ra0.32-2.5 and a flatness of 0.2-2 by magnetic adsorption or pasting, and then The plate medium is mounted on a printing station of a screen printer and fixed by vacuum fixing.

At the time of printing, the screen pattern 16 is first aligned with the shadow mask microholes 12, and then the blue phosphor paste prepared above is printed on the shadow mask 11 by screen printing, and the shadow mask is placed flat after printing. The platform was leveled for 10 to 15 minutes and placed under a microscope. The paste in the shadow mask hole was full, without blocking holes, and without bubbles. The shadow mask is directly placed in an oven at 150 ° C to 170 ° C for drying, and the drying time is 15 to 20 minutes. After drying, the phosphor film layer was observed under a microscope. It can be seen that the two layers and the bottom of the shadow mask hole are uniformly adhered to the phosphor layer without large particles or powder clusters, no voids, and no plugging. The shadow mask is placed in a sintering furnace for sintering, and the sintering temperature is 430 ° C to 500 ° C, 25 to 35 min. After the sintering is completed, it can be observed under the microscope. It can be seen that the phosphor layer is white, fine, without large powder clusters, no voids, no powder drop.

Second, a green phosphor slurry is prepared and made on the shadow mask 11:

5 g of organic resin ethyl cellulose, 0.5 g of Si0 ₂ nano powder and 50 g of organic solvent terpineol were mixed well, and an organic carrier was prepared under stirring in a water bath, and 44.5 g of green phosphor particles were sufficiently dispersed therein. A green phosphor slurry is formed.

Before printing, the shadow mask 11 printed with blue phosphor is first placed on a flat medium with a surface finish of Ra0.32-2.5 and a flatness of 0.2-2 by magnetic adsorption or pasting (soft magnetic Board, etc.), then the tablet It is mounted on the printing table of the screen printer and fixed by vacuum fixing.

When printing, the screen pattern 16 is first aligned with the shadow mask micro-hole 12 not printed with the phosphor, and then the green phosphor paste prepared above is printed on the shade printed with the blue phosphor by screen printing. On the cover 11, after printing, the shadow mask is placed flat on the platform for 10 to 15 minutes, and placed under a microscope to observe that the slurry in the shadow mask hole is full, without blocking holes, and without bubbles. The shadow mask is directly placed in an oven at 150 ° C to 170 ° C for drying, and the drying time is 15 to 20 minutes. After drying, the phosphor film layer was observed under a microscope. It can be seen that all the walls and the bottom of the shadow mask hole are uniformly adhered to the phosphor layer without large particles or powder clusters, no voids, and no plugging. The shadow mask was placed in a sintering furnace for sintering, and the sintering temperature was 430 ° C to 500 ° C, 25 to 35 min. After the sintering is completed, it is observed under the microscope, and the phosphor layer is white, fine, no large powder, no voids, no powder drop.

Third, preparing a red phosphor slurry and making it on the shadow mask 11;

4 g of organic resin ethyl cellulose, 2 g of SiO^fi rice powder and 54 g of organic solvent terpineol were mixed well, and an organic carrier was prepared under stirring in a water bath, and 40 g of red phosphor particles were sufficiently dispersed therein. , to form a red phosphor slurry.

Before printing, the shadow mask 11 printed with the blue phosphor and the green phosphor is first placed on the flat surface with a surface roughness of Ra0.32-2.5 and a flatness of 0.2-2 by magnetic adsorption or pasting. On the medium (soft magnetic board, etc.), the flat medium is then mounted on the printing table of the screen printing machine and fixed by vacuum fixing.

When printing, the screen pattern 16 is first aligned with the shadow mask micropores 12 not printed with the phosphor, and then the prepared red phosphor paste is printed on the printed blue and green phosphor film by screen printing. On the shadow mask, after printing, the shadow mask is placed flat on the platform for 10 to 15 minutes, and placed under a microscope to observe that the slurry in the shadow mask hole is full, without blocking holes, and without bubbles. The shadow mask is directly placed in an oven at 150 ° C to 170 ° C for drying, and the drying time is 15 to 20 minutes. After drying, the phosphor film layer was observed under a microscope. It can be seen that all the walls and the bottom of the shadow mask hole are uniformly adhered to the phosphor layer without large particles or powder clusters, no voids, and no plugging. The shadow mask was placed in a sintering furnace for sintering, and the sintering temperature was 430 ° C to 500 ° C, 25 to 35 min. After the sintering is completed, it is observed under the microscope, and the phosphor layer is white, fine, no large powder, no voids, no powder drop.

By analogy, the phosphor paste of the present invention can achieve various combinations, and will not be described herein. The phosphor paste prepared by the method of the present invention is dried and sintered to obtain a high-quality phosphor film layer, thereby obtaining a high-quality plasma display panel.

Claims

The invention provides a shadow mask type plasma display panel formed by phosphor printing on a shadow mask, which comprises a front plate (9), a rear plate (10) and a shadow mask (11) sandwiched between the front and rear plates, front The board (9) comprises a front substrate glass substrate (1), an electrode group (2), a dielectric layer (3) and a protective film (4), and the electrode group (2) is located on the glass substrate (1) and the dielectric layer (3) Between the protective film (4) covers the surface of the dielectric layer (3), the rear plate (10) includes the rear substrate glass substrate (5), the electrode group

(6), dielectric layer (7), protective film (8), electrode group (6) is located between the glass substrate (5) and the dielectric layer (7), and the protective film (8) is located in the dielectric layer (7) The surface mask (11) is a metal thin plate comprising an array of micropores (12), and the inner wall of the micropores (12) is provided with a phosphor layer, wherein the phosphor layer is screen printed. The method is shaped in the microwells (12).

The shadow mask plasma display panel formed by phosphor printing on the shadow mask according to claim 1, wherein the red (13) is printed on all the micropores (12) of the shadow mask according to a specific arrangement rule. Green (14), blue (15) three-color phosphor.

A shadow mask type plasma display panel for phosphor printing on a shadow mask according to claim 1, wherein said phosphors are all red phosphors (13), all of which are green phosphors (14) or All are blue phosphors (15). The shadow mask plasma display panel formed by phosphor printing on the shadow mask according to claim 1, wherein the micropores (12) on the shadow mask (11) are arranged in a strip shape, or Arranged according to the "product" shape.

A shadow mask type plasma display panel formed by phosphor printing on a shadow mask according to claim 1, wherein the screen printing pattern formed by the phosphor printing is an annular pattern matching the size and shape of the shadow mask opening ( 16).

A screen printing pattern for phosphor printing on a shadow mask according to claim 5, wherein the screen aperture (16) is designed to be in contact with all apertures in the shadow mask according to the arrangement of the shadow mask apertures in the SMPDP. One-to-one corresponding monochrome PDP phosphor printing screen; can also be designed as a three-color PDP phosphor printing screen corresponding to a single color hole on the shadow mask, the number of screen holes (16) is shade 1/3 of the number of cover holes.

A screen printing pattern for phosphor printing on a shadow mask according to claim 5, wherein the screen hole (16) is also designed as a four-sided concave cross ring (17) to avoid alignment. The dimensional deviation of the amplitude causes the color mixture to be printed.

A phosphor paste for phosphor printing on a shadow mask according to claim 1, wherein the phosphor paste is composed of a phosphor, an organic resin, an organic solvent and a nano powder, wherein the phosphor accounts for 40% of the total weight. 5〜3%。 The total weight of the total weight of 0. 5~3%. The phosphor paste for phosphor printing on a shadow mask according to claim 8, wherein the organic resin is ethyl cellulose, the organic solvent is terpineol, and the nano powder It is a nano powder such as Si0 ₂ , A1 ₂ 0 ₃ or Ti0 _{2 ,} and the phosphor is at least one of PDP monochromatic phosphors. A method for fixing a shadow mask for phosphor printing on a shadow mask according to claim 1, wherein the shadow mask (11) is first placed by magnetic adsorption or pasting at a surface roughness of Ra0.32. -2.5, a flat medium (soft magnetic board, etc.) with a flatness between 0.2 and 2, and then the flat medium is mounted on the printing table of the screen printing machine and fixed by vacuum fixing, and printing is performed. This method of combining vacuum with magnetic force solves the problem that the vacuum suction method cannot fix the shadow mask in the conventional screen printing.

A shadow mask plasma display panel formed by phosphor printing on a shadow mask according to claim 1, 5, 6, 7, 8, 9, 10, wherein the phosphor paste is printed on the shadow mask. Then, it is dried at 150 ° C to 17 (TC, 10 to 15 minutes, and then sintered at 430 ° C to 500 ° C for 25 to 35 minutes.

A shadow mask plasma display panel formed by phosphor printing on a shadow mask according to claim 1, wherein the monochrome phosphor layer can be formed to form a monochrome shadow mask plasma panel. A three-color phosphor layer can be fabricated to form a color shadow mask plasma display panel.