Method for forming partitions of plasma display panel by using sandblasting process
A partition is formed by the process including a step for providing a sheet-like partition material that covers a display area and outside thereof on the surface of the substrate, a step for providing a mask for patterning that covers the display area and the outside thereof, so that a pattern of the portion arranged outside of the display area of the mask is a grid-like pattern, a step for patterning the partition material covered partially with the mask by a sandblasting process, and a step for baking the partition material after the patterning.
Latest Fujitsu Hitachi Plasma Display Limited Patents:
This is a divisional reissue application of U.S. Reissue application Ser. No. 11/705,796, filed Feb. 14, 2007 now U.S. Pat. No. R,E41,312, which is a Reissue of U.S. Ser. No. 10/680,136, filed Oct. 8, 2003, now U.S. Pat. No. 6,855,026, contents of which are incorporated by reference herein.
This application is a continuing application, filed under 35 U.S.C. §111(a), of InternationalApplication PCT/JP02/03362, filed Apr. 2, 2002, it being further noted that foreign priority benefit is based upon Japanese Patent Application 2001-110647, filed Apr. 9, 2001.
TECHNICAL FIELDThe present invention is related to a method for forming partitions for manufacturing a plasma display panel (PDP) having partitions in a display area, and the invention can be applied to formation of partition using a sandblasting method.
BACKGROUND ARTA surface discharge type PDP that is used for a color display has partitions for preventing discharge interference between neighboring cells. There are two partition arrangement patterns. One is a stripe pattern in which a display area is divided into columns of a matrix display, and another is a mesh pattern in which the display area is divided into cells. When the stripe pattern is adopted, a plurality of partitions, each of which having a band-like shape in a plan view, is arranged in the display area. When the mesh pattern is adopted, a partition (a so-called box rib) having a shape surrounding each cell in a plan view is arranged in the display area.
In general, a partition is a baked material of low melting point glass and is formed by using a sandblasting method.
As shown in
Studying about the relationship between the phenomenon and the quantity of the projection of each portion in the panel, it is found that this phenomenon is prevented by reducing the quantity of the projection to a half of the current value, i.e., 16 μm or less, preferably 12 μm or less considering variation in the manufacturing process.
An object of the present invention is to provide a method for forming partitions of the exact pattern and height as designed in a display area without generating any projections that can be obstacles to contact between substrates.
DISCLOSURE OF THE INVENTIONAccording to a method for forming partitions of the present invention, when patterning a partition material that is masked partially by blasting a cutting material, the partition material is masked so as to form a sub partition that is connected to a partition in a display area (a main partition) outside the display area, thereby side cuts are generated outside the display area. In addition, the sub partition is formed as a grid-like pattern so that the side cuts can be generated in wide area for reducing the depth of the side cuts. When the side cuts are minute, mask exfoliation hardly happens, and a projection in baking scarcely occurs.
In a preferred embodiment, the partition material is masked so that the auxiliary partition for reducing the side cuts of the sub partition is formed outside the sub partition. When the edge portion of the auxiliary partition is protruded from the display area, the effect of protecting the sub partition in a cutting process is enhanced. Concerning the auxiliary partition too, the projection is prevented so that no disturbance is generated for contact between the substrates. As a measure for the prevention, the pattern of the auxiliary partition is made as a ring pattern. The ring pattern reduces concentration of stress due to thermal contraction so that the projection hardly occurs. As another measure for the prevention, a size of the pattern is set less than a predetermined value. Specifically, it is set to 240 μm or less. When forming a partition having the height of 140 μm by baking the partition material having the thickness of 200 μm, if the size of the pattern in the depth direction of the side cuts is 240 μm or less, the projection is very little even if the depth of the side cuts is 50 μm. When manufacturing partitions of a plurality of PDPs at the same time, the side cuts are generated more easily in the middle portion of the substrate than in the edge portion since deviation of the cutting material is little in the middle portion. Therefore, it is preferable to provide the auxiliary partition at least between neighboring display areas. Other various structures of the method for forming partitions according to the present invention will be explained later with reference to drawings.
The present invention will be described more in detail with reference to the attached drawings.
(First Embodiment)
A pattern of a portion of the mask 30 to be arranged in the display area 10 (hereinafter referred to as a main mask 3) is a stripe pattern corresponding to the partition to be formed, and it includes straight bands extending along the vertical direction in
It is effective to move the nozzle along the longitudinal direction of bands in cutting a stripe pattern. The direction of moving the nozzle is the vertical direction in
Since the reduction of the side cuts suppresses mask exfoliation and decreases a projection in the baking process, partitions can be formed of the exact pattern and height as designed in a display area without any obstruction in contact between the substrates. In addition, the sub partition arranged at the outside of the display area prevents incomplete contact between the substrates.
(Second Embodiment)
(1) At the same time as forming the mask 30b, auxiliary masks 5 are formed at both sides of the mask 30b and separated from the mask 30b.
(2) Among bands that constitute the pattern of the sub mask 4b and are formed in the direction perpendicular to the stripe partition, the most outside band is thicker than bands constituting the pattern of the main mask 3b.
(3) The corner portion of the sub mask 4b has an arcuate shape.
The auxiliary mask 5 has a role in adjusting the jet in the direction of the nozzle movement so as to reduce the side cuts securely at the portion that is masked by the sub mask 4b. Each of the auxiliary masks 5 has a stripe pattern in which seven long bands extend in parallel in the movement direction, and lateral ends of the auxiliary mask 5 protrude from the mask 30b by the length L11. This protrusion enhances the effect of the jet adjustment.
In addition, there is a following relationship concerning a width of a band that constitutes the pattern of the mask 30b.
L2>L1>L3
Here, L1 represents the width of bands except for both ends of the arrangement in the display area 10, L2 represents the width of the most outside band, and L3 represents the width of bands except for the most outside band in the non-display area 11. In this way, a patterning error of vanishing the most outside portion of the partition pattern can be prevented by setting the band width of the most outside portion to the largest value.
As explained above, the nozzle is moved in the vertical direction in
Making the corner portion of the sub mask 4b in an arcuate shape is effective for reducing the projection. It is considered to be important for the reason to distribute a stress due to contraction in the baking process so that the locally generated projection can be distributed and averaged. Concerning the pattern of the corner portion, there is a variation as shown in
The ring pattern is made by connecting both ends of a band with each other in the stripe pattern, and the exfoliation hardly occurs in it compared with the stripe pattern. Since ends of all rings including the most inside ring protrude from the mask 30b, the effect of protecting the mask 30b is enhanced.
The both ends of the auxiliary mask 5c protrude from the mask 30b by the length L11. However, the band closest to the mask 30b among bands constituting the stripe pattern is not protruded from the mask 30b. The reason thereof is to make the exfoliation of a band that will contribute to the protection of the mask 30b most hard to happen. If this band is exfoliated at early stage, quantity of side cut of the sub partition increases compared with the case where other bands are exfoliated. Since the ends of the band are not protruded from the mask 30b, jet pressure will be weaken at the end of the band. Furthermore, the shape of the band that is closest to the mask 30b can be adopted also for the auxiliary mask of the embodiment as shown in
(Third Embodiment)
The display areas 10a, 10b and 10c are arranged with a space along the vertical direction in
As explained above, according to the present invention, concerning a projection based on the display portion, over the entire area of the partition forming portion including the sub partition portion and its corner portion and auxiliary partition portion, the quantity of a projection can be suppressed to 12 μm or less. Even if variation among manufactured panels is taken into account, it can be suppressed to 16 μm or less. Thus, operation sound (buzz sound) due to vibration during operation of the panel can be suppressed.
Though the present invention has been explained using various embodiments and variations, the present invention is not limited to these embodiments but can be realized in other embodiments.
INDUSTRIAL APPLICABILITYThe method for forming partitions according to the present invention enables formation of partitions having exact pattern and height as designed in a display area without generating projections that may disturb the contact between substrates. Therefore, it is useful for improving yields in manufacturing the plasma display panel that can be lowered due to patterning errors and for providing a plasma display panel that does not generate vibration sound due to insufficient contact between substrates.
Claims
1. A method for forming partitions of a plasma display panel, the partitions dividing a discharge space of a plasma display panel, the method comprising the steps of:
- providing a sheet-like partition material on a substrate that is a panel material, the partition material covering a display area and outside thereof on a surface of the substrate;
- providing a mask for patterning on the partition material, the mask covering the display area and the outside thereof, so that a pattern of the portion arranged in the display area of the mask corresponds to the partitions, and a pattern of the portion arranged outside of the display area of the mask is a pattern for dividing a band-like portion along a rim of the display area as a grid;
- patterning the partition material covered partially with the mask by a sandblasting process; and
- baking the partition material after the patterning.
2. The method for forming partitions of a plasma display panel according to claim 1, further comprising the steps of:
- providing the mask so as to cover the display area and both sides thereof in a first direction; and
- moving a nozzle for ejecting a cutting material relatively to the partition material in the first direction in a reciprocating manner while patterning the partition material by the sandblasting process.
3. The method for forming partitions of a plasma display panel according to claim 2, further comprising the step of forming an auxiliary mask outside the mask in the first direction with a distance from the mask at the same time when forming the mask.
4. The method for forming partitions of a plasma display panel according to claim 3, wherein both ends of the auxiliary mask in a second direction that is perpendicular to the first direction protrudes from the mask.
5. The method for forming partitions of a plasma display panel according to claim 4, wherein the pattern of the auxiliary mask is a stripe pattern in which a plurality of long bands is arranged in parallel in the second direction.
6. The method for forming partitions of a plasma display panel according to claim 4, wherein the pattern of the auxiliary mask is a stripe pattern in which a plurality of long thin bands is arranged in parallel in the second direction and at least both ends of the band that is closest to the mask are not protruded from the mask.
7. The method for forming partitions of a plasma display panel according to claim 4, wherein the pattern of the auxiliary mask is a ring pattern that is oblong in the second direction.
8. The method for forming partitions of a plasma display panel according to claim 1, wherein a corner portion of the mask has an arcuate shape.
9. The method for forming partitions of a plasma display panel according to claim 4, wherein the pattern of the auxiliary mask is a pattern in which a plurality of bands that is shorter than the entire length of the display area in the second direction is arranged in parallel to each other as a plurality of discontinuous lines along the second direction.
10. The method for forming partitions of a plasma display panel according to claim 9, wherein discontinuous points are shifted from each other among the plural discontinuous lines in the pattern of the auxiliary mask.
11. The method for forming partitions of a plasma display panel according to claim 9, wherein the length of the band in the pattern of the auxiliary mask has a value within the range of 0.05-200 mm.
12. The method for forming partitions of a plasma display panel according to claim 9, wherein both the width and the length of the band in the pattern of the auxiliary mask have a value less than 240 μm.
13. The method for forming partitions of a plasma display panel according to claim 1, wherein at least the width of the band located at the most outside portion among the bands constituting a grid-like pattern of the portion arranged outside of the display area of the mask has a value within the range of 160-320 μm.
14. A method for forming partitions that divide a discharge space in each of plural plasma display panels simultaneously, the method comprising the steps of:
- providing a sheet-like partition material on a substrate that is a panel material on which display areas corresponding to the plurality plasma display panels respectively are arranged linearly, the partition material covering the plural display areas and outside thereof on a surface of the substrate;
- providing a mask for patterning on the partition material, the mask covering the inside and the outside of the display area for each display area, so that a pattern of the portion arranged in the display area of the mask corresponds to the partitions, and a pattern of the portion arranged outside of the display area of the mask is a pattern for dividing a band-like portion along a rim of the display area as a grid;
- forming an auxiliary mask at least between neighboring masks with a distance from the mask at the same time when forming the mask;
- patterning the partition material covered partially with the mask and the auxiliary mask by a sandblasting process; and
- baking the partition material after the patterning.
15. A plasma display panel, comprising:
- a substrate;
- a first partition area arranged in a display area on the substrate; and
- second partition area arranged outside of the display area on the substrate;
- wherein the first partition area includes a plurality of partitions extending at least in a first direction;
- wherein the second partition area includes at least three first partitions extending in the first direction and at least three second partitions extending in a second direction, the first partitions extending in the first direction and the second partitions extending in the second direction extending transversely to one another; and
- wherein a corner portion of the second partition area is arcuate.
16. A plasma display panel according to claim 15, wherein the second partition area further includes a third partition, and wherein the third partition forms the corner portion of the second partition area and has an arcuate shape.
17. A plasma display panel according to claim 16, wherein an edge portion of the third partition is connected to an edge portion of the outermost first partition and another edge portion of the third partition is connected to an edge portion of the outermost second partition.
18. A plasma display panel according to claim 16, wherein the third partition has an entirely curved shape extending from an edge portion connected to an edge portion of the outermost first partition to another edge portion connected to an edge portion of the outermost second partition.
19. A plasma display panel according to claim 15, wherein the first partition area corresponds to a rectangular display area, and wherein the second partition area extends along at least one edge of the rectangular display area.
20. A plasma display panel according to claim 19, wherein the second partition area extends along a longer edge of the rectangular display area.
21. A plasma display panel according to claim 15, wherein a projection formed at the corner portion of the second partition area has a height which is not greater than 16 μm.
22. A plasma display panel according to claim 21, wherein the projection has a height which is not greater than 12 μm.
23. A plasma display panel according to claim 21, wherein the first partition area corresponds to a rectangular display area, and wherein the second partition area extends along at least one edge of the rectangular display area.
24. A plasma display panel according to claim 15, wherein the first and second partitions are formed by a sandblasting method.
25. A plasma display panel, comprising:
- a substrate;
- a first partition area arranged in a display area on the substrate; and
- a second partition area arranged outside of the display area on the substrate;
- wherein the first partition area includes a plurality of horizontal partitions and vertical partitions;
- wherein the second partition area includes a plurality of horizontal partitions and a plurality of vertical partitions, the horizontal partitions and the vertical partitions intersect one another, forming a plurality of first cells arranged in a plurality of rows and a plurality of columns; and
- wherein a second cell is formed in a corner portion of the second partition area and has an arcuate partition.
26. A plasma display panel according to claim 25, wherein the second cell is formed by the outermost horizontal partition, the outermost vertical partition and a third partition which is the arcuate partition, and wherein the third partition connects an edge portion of the horizontal partition and an edge portion of the vertical partition.
27. A plasma display panel according to claim 25, wherein the second partition area extends along a longer edge of the rectangular display area.
28. A plasma display panel according to claim 25, wherein a projection formed at the corner portion of the second partition area has a height which is not greater than 16 μm.
29. A plasma display panel according to claim 28, wherein the projection has a height which is not greater than 12 μm.
30. A plasma display panel according to claim 25, wherein the horizontal and vertical partitions are formed by a sandblasting method.
31. A plasma display panel, comprising:
- a substrate;
- a first partition area arranged in a display area on the substrate; and
- a second partition area arranged outside of the display area on the substrate;
- wherein the first partition area includes a plurality of partitions;
- wherein the second partition area includes a plurality of first partitions and a plurality of second partitions which extend transversely to one another and form first cells;
- wherein the second partition area further includes third partitions forming second cells; and
- wherein at least one of the second cells has a size greater than at least one of the first cells.
32. A plasma display panel according to claim 31, wherein in a horizontal direction, a length of the second cell is greater than a length of an adjacent first cell.
33. A plasma display panel according to claim 31, wherein in a vertical direction, a length of the second cell is greater than a length of an adjacent first cell.
34. A plasma display panel according to claim 31, wherein in the horizontal direction, a length of the second cell corresponds to a length of a plurality of adjacent first cells.
35. A plasma display panel according to claim 31, wherein in the vertical direction, a length of the second cell corresponds to a length of a plurality of adjacent first cells.
36. A plasma display panel according to claim 31, wherein the second cell is arranged in a corner portion of the second partition area.
37. A plasma display panel according to claim 36, wherein the third partition of the second cell has an arcate shape.
38. A plasma display panel according to claim 31, wherein the first partition area corresponds to a rectangular display area, and wherein the second partition area extends along at least one edge of the rectangular display area.
39. A plasma display panel according to claim 31, wherein the second partition area extends along a longer edge of the rectangular display area.
40. A plasma display panel according to claim 31, wherein a projection formed at a corner portion of the second partition area has a height which is not greater than 16 μm.
41. A plasma display panel according to claim 40, wherein the projection has a height which is not greater than 12 μm.
42. A plasma display panel according to claim 31, wherein all of the partitions are formed by a sandblasting method.
43. A plasma display panel, comprising:
- a substrate;
- a first partition area arranged in a display area on the substrate; and
- a second partition area arranged outside of the display area on the substrate;
- wherein the first partition area includes a plurality of partitions extending at least in a first direction;
- wherein the second partition area includes a plurality of first partitions and a plurality of second partitions, the first partitions and the second partitions extending transversely to one another; and
- wherein an outermost partition of the second partition area has a thickness greater than a thickness of inner partitions in the second partition area.
44. A plasma display panel according to claim 43, wherein the outermost partition in the second partition area has a thickness greater than a thickness of inner partitions in the first partition area.
45. A plasma display panel according to claim 44, wherein a projection formed at a corner portion of the second partition area has a height which is not greater than 16 μm.
46. A plasma display panel according to claim 45, wherein the projection has a height which is not greater than 12 μm.
47. A plasma display panel according to claim 44, wherein all of the partitions are formed by a sandblasting method.
5684362 | November 4, 1997 | Togawa |
5989089 | November 23, 1999 | Ichiyoshi et al. |
6048243 | April 11, 2000 | Kosaka et al. |
6249264 | June 19, 2001 | Sano et al. |
6400080 | June 4, 2002 | Tanaka |
6465956 | October 15, 2002 | Koshio |
6638129 | October 28, 2003 | Sano et al. |
6683589 | January 27, 2004 | Sano et al. |
20010019318 | September 6, 2001 | Sano et al. |
20010026255 | October 4, 2001 | Sano et al. |
20020110759 | August 15, 2002 | Lin et al. |
1017081 | July 2000 | EP |
7-045193 | February 1995 | JP |
11-007897 | January 1999 | JP |
11-191377 | July 1999 | JP |
11-213896 | August 1999 | JP |
2000-311612 | November 2000 | JP |
2001-052616 | February 2001 | JP |
2001-236890 | August 2001 | JP |
- Display Technologies III Jul. 26-27, 2000 Taipei, Taiwan, vol. 4079, 2000, pp. 70-78, XP002446415 Proceedings of the SPIE—The International Society For Optical Engineering SPIE—Int. Soc. Opt. Eng USA, ISSN 0277-786X.
- New Cell Structure And New Driving Method for PDPs, Taniguchi et al, ISSN 0913-5685, vol. 99, No. 597 Jan. 27, 2000.
Type: Grant
Filed: Dec 4, 2008
Date of Patent: May 31, 2011
Assignees: Fujitsu Hitachi Plasma Display Limited (Kanagawa), Hitachi Plasma Patent Licensing Co., Ltd. (Tokyo)
Inventors: Akihiro Fujinaga (Kanagawa), Kazunori Ishizuka (Miyazaki), Tatsutoshi Kanae (Kanagawa), Kazuhide Iwasaki (Kanagawa), Toshiyuki Nanto (Kanagawa), Yoshimi Kawanami (Kanagawa), Masayuki Shibata (Kanagawa), Yasuhiko Kunii (Kanagawa), Tadayoshi Kosaka (Kanagawa), Osamu Toyoda (Kanagawa), Yoshimi Shirakawa (Kanagawa)
Primary Examiner: Toan Ton
Assistant Examiner: Hana S Featherly
Attorney: Antonelli, Terry, Stout & Kraus, LLP.
Application Number: 12/328,197
International Classification: H01J 17/49 (20060101);