JP2006073314A - Manufacturing method of display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a display device capable of forming a flat metal-back layer. <P>SOLUTION: A metal back layer is formed on a flat dummy board, by interposing a resin film using a photolithography technology; a phosphor screen is formed on top of it; thereafter a front substrate is fixed, by interlaying a fixing material from the phosphor screen side; the dummy board is separated; and the resin film is removed by burning it. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a flat display device in which a front substrate having a phosphor layer and a metal back layer and a rear substrate having a large number of electron-emitting devices are arranged to face each other.

  2. Description of the Related Art In recent years, various flat-type image display devices have attracted attention as next-generation lightweight and thin display devices that replace cathode ray tubes (hereinafter referred to as CRTs). For example, as a type of field emission display (hereinafter referred to as FED) used as a flat display device, development of a display device (hereinafter referred to as SED) including a surface conduction electron-emitting device as an electron source is being promoted. ing.

  The SED includes a front substrate and a rear substrate that are arranged to face each other at a predetermined interval, and these substrates constitute a vacuum envelope by joining peripheral portions to each other through a rectangular frame-shaped side wall. Yes. A phosphor screen including a phosphor layer of three colors and a light shielding layer is formed on the inner surface of the front substrate, and on the inner surface of the rear substrate, as an electron source for exciting and emitting the phosphor, a large number corresponding to each pixel is formed. The electron-emitting devices are arranged. Each electron-emitting device includes an electron-emitting portion and a pair of electrodes that apply a voltage to the electron-emitting portion. Further, a metal back layer is formed on the phosphor screen to act as an anode electrode and to reflect light from the phosphor layer excited and emitted to the front substrate side.

  As a method of forming this metal back layer, for example, a method of forming a metal back layer on a phosphor screen after flattening the surface of a phosphor screen as a base in advance is known.

  In general, when leveling a layer printed on the surface of the substrate, a method is adopted in which the surface on which the printed layer is formed faces up and the substrate is left in the air for a certain period of time to flatten the surface of the printed layer.

In addition, for example, a technique is disclosed in which hot air is applied to reduce the viscosity of the alignment film and eliminate unevenness on the printed alignment film surface (see Patent Document 1).
JP2003-57625A.

  However, it takes time for a printed layer made of a viscous material to be flattened, for example, until the surface of a phosphor screen formed of a phosphor layer and a black matrix layer formed on a flat substrate mounted on a display device becomes flat. Takes about 30 minutes to 60 minutes. As a result, there is a problem that the manufacturing time becomes long.

  Further, the phosphor screen that is the base of the metal back layer is not flat because the phosphor layer and the light shielding layer in the form of dots or stripes are formed, and a flat metal back layer is formed on the non-flat base. It was difficult to form. In addition, if the metal back layer is not flat, the light from the phosphor layer is not sufficiently reflected, resulting in a problem that the luminance of the display device is lowered.

  The present invention has been made in view of the above points, and an object thereof is to provide a method of manufacturing a display device capable of forming a metal back layer having a high reflectance.

  In order to achieve the above object, a manufacturing method of a display device of the present invention includes a step of forming a metal back layer on a first substrate, and a plurality of phosphor layers and a light shielding layer on the metal back layer. The method includes a step of forming a phosphor screen, a step of bonding a second substrate on the phosphor screen, and a step of peeling off the first substrate from the metal back layer.

  According to the present invention, the metal back layer can be flattened, and the luminance of the display device can be increased.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, an SED will be described as an example of a display device according to an embodiment of the present invention.

  FIG. 1 is a schematic perspective view of a display panel of an SED. As shown in FIG. 1, a display panel 1 of an SED includes a front substrate 10 and a rear substrate 12 each made of a rectangular glass plate, and these substrates are arranged to face each other with a certain gap. The distance between the substrates is set to about 1.0 to 2.0 mm. The front substrate 10 and the rear substrate 12 are joined to each other through a rectangular frame-shaped side wall 14 made of glass, and constitute a flat vacuum envelope having a vacuum inside.

  As shown in FIG. 2, a phosphor screen 16 that functions as an image display surface is formed on the inner surface of the front substrate 10. The phosphor screen 16 is configured by arranging red, green, and blue phosphor layers R, G, and B, and a light shielding layer 11, and these phosphor layers R, G, and B are formed in stripes or dots. ing. A metal back layer 17 made of aluminum or the like is formed on the phosphor screen 16.

  On the inner surface of the rear substrate 12, a number of surface-conduction electron-emitting devices 19 that emit electron beams are provided as electron sources for exciting and emitting the phosphor layers R, G, and B of the phosphor screen 16. ing. These electron-emitting devices 19 are arranged in a plurality of columns and a plurality of rows corresponding to each pixel. Each electron-emitting device 19 includes an electron emitting portion (not shown) and a pair of device electrodes for applying a voltage to the electron emitting portion. In addition, on the inner surface of the back substrate 12, a large number of wirings 21 for supplying a voltage to the electron-emitting devices 19 are provided in a matrix shape, and end portions thereof are drawn out of the display panel 1.

  The side wall 14 functioning as a bonding member is sealed to the peripheral edge of the front substrate 10 and the peripheral edge of the rear substrate 12 by, for example, a sealing material 20 such as low melting glass or low melting metal, and these substrates are bonded to each other. is doing.

  Further, the display panel 1 includes a rectangular plate-like spacer 22 disposed between the front substrate 10 and the rear substrate 12. The spacers 22 are arranged in a stripe shape, abut against the inner surfaces of the front substrate 10 and the rear substrate 12 so as not to interfere with the respective electron-emitting devices 19 and the phosphor layers R, G, B, and act on these substrates. The atmospheric pressure load is supported, and the distance between the substrates is maintained at a predetermined value. The shape of the spacer is not limited to this, and may be a number of columnar spacers, for example.

  When displaying an image, the electron-emitting device 19 is driven through the wiring 21 to emit an electron beam from the selected electron-emitting device, and an anode voltage is applied to the phosphor layer 16 and the metal back layer 17. The electron beam emitted from the electron emitter 19 is accelerated by the anode voltage and collides with the phosphor layer 16. As a result, the phosphor layers R, G, and B of the phosphor screen 16 are excited to emit light and display an image.

  FIG. 3 is a schematic view for explaining the metal back layer 17 in more detail.

  As shown in FIG. 3, the metal back layer 17 includes a plurality of divided regions 17 </ b> A and a thin high-resistance region 17 </ b> B that connects the divided regions 17 </ b> A, and is connected to a common electrode formed on the peripheral portion of the front substrate 10.

  The divided region 17A is formed at a position corresponding to the phosphor layers R, G, and B, that is, a position corresponding to the pixel.

  In the high resistance region 17B, when a plurality of divided regions 17A are connected in a row in the direction of arrow X, the size in the direction of arrow X is length, and the size in the direction of arrow Y is width, the width of the high resistance region 17B is It is narrower than the width of the divided region 17A. That is, the high resistance region 17B is thinner than the dividing region 17A. For this reason, the high resistance region 17B has a higher resistance than the dividing region 17A.

  Thus, the metal back layer 17 is divided into a large number of elements by a large number of high resistance regions 17B.

  Next, the manufacturing method of SED mentioned above is demonstrated using FIGS. 4-10.

  First, as shown in FIG. 4, a resin film 32 is disposed on the entire surface of a dummy substrate 30 (first substrate) having a flat surface. Aluminum is vapor-deposited on the resin film 32, a mask pattern having a pattern as shown in FIG. 3 is formed on the aluminum film, and exposed to remove aluminum other than the mask pattern. 17 and the common electrode 18 are formed. That is, the metal back layer 17 and the common electrode 18 were formed using a photolithography technique.

  Thereafter, as shown in FIG. 5, phosphor layers R, G, and B are formed on the divided region 17A on the metal back layer 17 by using a photolithography technique. Further, on each of the phosphor layers R, G, and B, a microfilter (MF) corresponding to each color of the phosphor layers R, G, and B is used for color correction of the phosphor layers R, G, and B. ) 16R, 16G, and 16B are formed using a photolithography technique. Therefore, a stack of phosphor layers R, G, and B that form a large number of pixels on the dots and MFs 16R, 16G, and 16B corresponding to the respective pixels is formed at positions corresponding to the divided regions 17A.

  Further, as shown in FIG. 6, the light shielding layer 11 is printed in a stripe shape between the phosphor layers R, G, and B and the corresponding MF 16R, 16G, and 16B, and fired and printed. The light shielding layer 11 is stabilized. Thereby, the phosphor screen 16 is formed.

  On the dummy substrate 30 including the phosphor screen 16 and the common electrode 18, as shown in FIG. 7, a fixing material (for example, a silica agent) to be the fixing layer 15 is disposed, and an organic solvent is removed from the silica agent or the like. In order to fly, the silica agent is dried by heating or blowing.

  Thereafter, as shown in FIG. 8, the front substrate (second substrate) 10 is disposed, and the phosphor screen 16 and the like and the front substrate 10 are sufficiently fixed via the fixing layer 15. Press. This pressurization increases the adhesion between the phosphor screen 16 and the front substrate 10. Further, heating may be performed so that the dummy substrate 30 and the resin film 32 can be easily peeled off.

  Then, as shown in FIG. 9, for example, the front substrate 10 is turned down and placed, the dummy substrate 30 and the resin film 32 are peeled off, and as shown in FIG. Bake the film.

  By this firing, the resin film 32 is vaporized and substantially disappears. Further, the fixing layer 15 on the front substrate 10 can also be fired by adjusting the firing temperature.

  Thus, the metal back layer 17 is formed on the dummy substrate 30 having a flat surface via the resin film 32 as shown in FIG. Therefore, the metal back layer 17 is formed to be very flat like a mirror surface. As a result, the luminance of the display device including the metal back layer 17 manufactured by this method is improved by about 10% compared to the conventional case.

  Incidentally, in the conventional method, a metal back layer is directly formed on a phosphor screen composed of a phosphor layer and a light shielding layer, or a metal is formed on an adhesive film (FHS) for flattening the surface of the phosphor screen. A back layer was formed. Therefore, it is difficult and limited to form a flat metal back layer on the surface of the non-flat phosphor screen. Further, since FHS is formed between the phosphor screen and the metal back layer, it may be removed by firing after the metal back layer is formed, but part of the FHS may remain. In this case, there is a problem that the gas generated from the residue of FHS lowers the degree of vacuum of the display device and causes failure and display failure.

  The display device manufactured by the manufacturing method of the present invention can solve such a conventional problem, does not require a configuration for flattening the metal back layer such as FHS, and has a metal back like a very flat mirror surface. Layers can be formed.

  Further, according to the present invention, the metal back layer 17 can be formed by a photolithography technique using a mask pattern corresponding to a pixel as shown in FIG. In this way, the metal back layer 17 composed of the plurality of divided regions 17A and the thin high resistance regions 17B connecting the divided regions 17A is formed. It is divided. With this configuration, even when a strong electric field is formed in a small gap between the front substrate 10 and the rear substrate 12 and a discharge (dielectric breakdown) occurs between the two substrates, the phosphor screen 16, the metal back layer 17, Alternatively, the influence on the electron-emitting device 19 can be suppressed to a negligible level.

  Incidentally, when the metal back layer having the mask pattern as shown in FIG. 3 is formed on the phosphor screen by the photolithography technique using the above-described conventional method, the lower phosphor screen is damaged, and the display device is displayed. When it is incorporated in the display, there is a possibility that display unevenness occurs.

  Furthermore, according to the present invention, the phosphor layers R, G, and B, the MFs 16R, 16G, and 16B, and the metal back layer 17 are formed corresponding to the pixels by a photolithography technique with high positional accuracy. For this reason, the laminate of the phosphor layers R, G, and B and the MFs 16R, 16G, and 16B corresponding to the phosphor layers R, G, and B, respectively, is formed with high accuracy on the dividing region 17A. Thus, since each of the phosphor layers R, G, B, MF16R, 16G, 16B, and the metal back layer 17 can be formed at a specific position corresponding to the pixel, the positional accuracy with respect to the pixel is improved.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, you may delete some components from all the components shown by embodiment mentioned above.

  For example, the phosphor layers R, G, B and MF16R, 16G, 16B may be formed by printing or an inkjet method.

  The fixing layer 15 also functions as an insulating precoat (PC) provided between the front substrate 10 and the phosphor screen 16, and other fixing materials having insulating properties are used besides the silica agent. May be.

  Furthermore, the dummy substrate 30 may be a glass substrate similar to the front substrate 10 or a resin substrate made of a hard resin material. When a hard resin substrate is used as the dummy substrate 30, it can be substantially eliminated by baking as shown in FIG. 10 without peeling off the dummy substrate 30 as shown in FIG. In this case, when the dummy substrate 30 is peeled off, the stress acting on the phosphor screen 16 and the metal back layer 17 can be reduced, and the work process can be simplified.

  Further, the resin film 32 is temporarily adhered to the dummy substrate 30 and finally peeled off from the dummy substrate 30 as shown in FIG. 9, and disappears by firing as shown in FIG. Therefore, in this embodiment, a resin film made of a cellulose-based resin such as nitrocellulose or ethylcellulose that disappears by baking at about 400 ° C. and having a thickness of about 100 μm is used. If it is about 400 degrees, there is no possibility that the phosphor screen 16 and the metal back layer 17 contract or warp due to firing.

  Further, in place of the resin film 32, a release layer containing a release agent is provided on the dummy substrate 30, and the metal back layer 17 is formed on the release layer so that the dummy substrate 30 can be easily peeled off. May be. Alternatively, a method may be used in which the metal back layer 17 is formed directly on the dummy substrate 30 made of a hard resin without using the resin film 32, and finally the dummy substrate 30 disappears by baking.

  In this case, as described above, the metal back layer 17 and the common electrode 18 are formed on the dummy substrate 30 using the photolithography technique, and the phosphor layers R and G are formed at positions corresponding to the divided regions 17A of the metal back layer 17. , B and MF16R, 16G, 16B are formed, and the light shielding layer 11 is printed so as to partition the phosphor layers R, G, B and the corresponding MF16R, 16G, 16B, and the light shielding layer. 11 is fired to stabilize, and a silica agent 15 as a fixing material is disposed on the laminate composed of each of the phosphor layers R, G, B and MF16R, 16G, 16B, and the light shielding layer 11, and silica In order to fly away the organic solvent of the agent, the substrate is dried, and the front substrate 10 is placed on the silica agent 15 and pressurized, and the dummy substrate 30 is eliminated by baking. Thereby, the front substrate 10 on which the fixing layer 15, the phosphor screen 16, the metal back layer 17, and the common electrode 18 are formed as shown in FIG. 2 can be manufactured.

  Further, the dummy substrate 30 may be a foldable plastic sheet used for a flexible circuit board. With this configuration, since the dummy substrate 30 which is a plastic sheet can be peeled off while being deformed, the stress acting on the phosphor screen 16 and the metal back layer 17 can be reduced.

Schematic which shows an example of the display panel which is one embodiment of this invention, 1 is a schematic cross-sectional view of the display panel shown in FIG. Schematic showing the pattern of the metal back layer shown in FIG. Sectional drawing which shows 1 process of the manufacturing method of the display apparatus which is one embodiment of this invention, Sectional drawing which shows the process following the process shown in FIG. Sectional drawing which shows the process following the process shown in FIG. Sectional drawing which shows the process following the process shown in FIG. Sectional drawing which shows the process following the process shown in FIG. Sectional drawing which shows the process following the process shown in FIG. FIG. 10 is a cross-sectional view showing a step that follows the step shown in FIG. 9.

Explanation of symbols

1 ... Display panel,
10: Front substrate,
11 ... light shielding layer,
R, G, B ... phosphor layer,
15 ... Fixed layer,
16 ... Phosphor screen 16R, 16G, 16B ... Microfilter (MF)
17 ... metal back layer,
17A: Divided area,
18 ... Common electrode,
19 ... an electron-emitting device,
30 ... dummy substrate,
32 ... Resin film.

Claims (10)

Forming a metal back layer on the first substrate;
Forming a phosphor screen including a plurality of phosphor layers and a light shielding layer on the metal back layer;
Adhering a second substrate on the phosphor screen;
And a step of peeling off the first substrate from the metal back layer.   The method for manufacturing a display device according to claim 1, wherein the metal back layer is formed using a photolithography technique and includes a plurality of divided regions and a thin high-resistance region that connects the divided regions.   3. The step of disposing a cellulose resin film such as nitrocellulose or ethyl cellulose on the surface of the first substrate on which the metal back layer is to be formed before forming the metal back layer. Display device manufacturing method. The step of forming the phosphor screen includes:
Forming the plurality of phosphor layers on the metal back layer;
Forming a microfilter for color correction according to the color of the phosphor layer on the phosphor layer;
4. The display device manufacturing method according to claim 1, further comprising a step of forming a light-shielding layer between the phosphor layer and the laminate made of the microfilter. 5. In the step of forming the phosphor layers of the plurality of colors, the phosphor layer is formed by a photolithography technique,
5. The method for manufacturing a display device according to claim 1, wherein in the step of forming the microfilter, the microfilter is formed by a photolithography technique. 6. In the step of forming the phosphor layers of the plurality of colors, the phosphor layer is formed by printing,
5. The method for manufacturing a display device according to claim 1, wherein in the step of forming the microfilter, the microfilter is formed by printing. 6. In the step of forming the plurality of color phosphor layers, the phosphor layer is formed by an inkjet method,
5. The method for manufacturing a display device according to claim 1, wherein in the step of forming the microfilter, the microfilter is formed by an inkjet method.   The display device manufacturing method according to claim 1, wherein the second substrate is bonded by an adhesive containing a silica agent. The adhesive is disposed on the phosphor screen;
The method for manufacturing a display device according to claim 8, further comprising a step of drying the adhesive to fly away the organic solvent contained in the adhesive.   10. The method according to claim 1, further comprising a step of applying pressure from a stacking direction in order to make the metal back layer flatter after the second substrate is bonded onto the phosphor screen. The manufacturing method of the display apparatus as described in any one of.

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