JP4773137B2 - Cold cathode display device and method for producing the same - Google Patents

Description

  The present invention relates to a cold cathode display element and a manufacturing method thereof.

  In the past, research into the practical application of a field electron emission display device has been performed mainly using a silicon chip formed by anisotropic etching of a silicon substrate for an emitter. However, in addition to technical difficulties in manufacturing a silicon chip, there are many problems such as a high operating voltage and a decrease in device performance due to deterioration of the silicon chip due to high current discharge. Therefore, attempts have been made to use various excellent physical properties of carbon nanomaterials such as graphite nanofibers in the semiconductor field. For example, graphite nanofibers are attracting attention as cathode materials that can achieve high electron emission density and low field electron emission performance.

  In recent years, field electron emission display devices having emitters made of carbon-based materials have been developed and improved in the field of display applications, etc., coupled with improvements in the manufacturing method of the cathode material. In this case, considering the manufacturing process peculiar to the carbon-based emitter and the emitter shape, how to produce an element structure having a display performance with little variation and whether it can be applied to a large area display element. Improvement is an urgent need.

  Carbon-based emitters are superior in electron emission stability compared to silicon chips. However, in order to form by chemical vapor deposition using a catalyst, etc., in the conventional fabrication process, the variation in emitter characteristics in the substrate compared to the silicon chip fabrication process fabricated by anisotropic etching on the silicon substrate. There was a drawback that only large ones could be obtained. This is because an independent micron-sized carbon-based emitter is formed with reduced variation in characteristics by chemical vapor deposition over the entire substrate on which a display element having a size of several tens of μm or more and an aggregate thereof are formed. This is because it involves great technical difficulties.

  FIG. 7 shows a manufacturing process diagram of a conventional field emission display device, FIG. 8 schematically shows an example of the emitter arrangement of the obtained device, and FIG. 9 shows a cross-sectional structure of the cathode portion of the obtained display device. Is shown schematically. In this case, 100 emitters arranged in a grid pattern with a pitch of 10 μm are provided in the gate electrode layer corresponding to the size of the display element (100 μm × 100 μm), and the configuration mainly focuses on the light emission uniformity within the element. It is. However, when carbon-based emitters are used as emitters, problems such as the presence of many emitters with significantly inferior electron emission characteristics often occur depending on the manufacturing process. This is due to the dispersion of the characteristics of the carbon itself that constitutes the emitter, as well as the electron divergence due to the electric field relationship between the emitter material growing from the cathode electrode toward the gate electrode and the gate electrode. And lowering of the electron emission amount. 7 to 9 will be described in detail in Comparative Example 1 described later.

FIGS. 7 to 9 show examples in which each emitter is surrounded by an insulating layer. However, as a gate electrode having a mesh structure between a large number of vertically aligned carbon nanotubes as emitter chips and RGB three-color phosphors. A structure of a field electron emission display element having a metal film has been proposed mainly for the simplification of the structure and the simplification of the manufacturing process (see, for example, Patent Document 1). In this case, the gate electrode is supported only by the first spacer on the outer periphery of the display element, and the lower cathode portion and the upper anode portion are attached only by the second spacer on the outer periphery of the element.
JP 2001-176431 A (claims, paragraph number 0006, etc.)

  As described above, it may be possible to efficiently emit light from the phosphor disposed at a position facing the emitter by suppressing the divergence of electrons emitted from the emitter by using the mesh structure of the gate electrode. However, when manufacturing a gate electrode having such a mesh structure, the electrode is considered in relation to the light emitting area of the element in consideration of strength so that the gate electrode is held in the element without being short-circuited while maintaining its shape. However, there are too many restrictions for designing an element of a predetermined size, and there is a problem that the practical range is limited.

  An object of the present invention is to solve the above-mentioned problems of the prior art, which is easy to manufacture, has a display performance with little variation, can display a large area, and has no deformation of the gate electrode. An object of the present invention is to provide a field electronic display device and a method for manufacturing the same.

This onset Ming, hollow penetrating provided between the cathode electrode layer formed on the lower substrate, and the cathode electrode layer formed above the gate electrode layer, and the cathode electrode layer and the gate electrode layer An insulating layer having an emitter, an emitter provided on the exposed surface of the cathode electrode layer in the cavity, a phosphor layer provided on the gate electrode layer, and an anode electrode provided on the phosphor layer In a cold cathode display device comprising a layer and an upper substrate , the cavity is composed of one through hole, and at least one, preferably a plurality of support layers made of the insulating layer is included in the cavity, A plurality of emitters are uniformly provided, and the gate electrode layer has a mesh structure having an emitter hole at least above each of the plurality of emitters. In this case, the cavity opening ratio of is in the range of 20% to 70% in the insulating layer total surface area basis, also the cavity is also one which is formed by etching after formation of a gate electrode layer having a mesh structure is there. The gate electrode layer is supported by a support post made of an insulating layer. Furthermore, also in this case, the cathode portion composed of the lower substrate, the cathode electrode layer, the gate electrode layer, the insulating layer, and the emitter, and the anode portion composed of the phosphor layer, the anode electrode layer, and the upper substrate are included in the display element. It is spread through a support provided on the outer periphery.

  In the cold cathode display device of the present invention, the diameter of the emitter hole is 3 μm or less, preferably in the range of 0.5 μm to 3 μm, and the thickness of the insulating layer is 2 to 5 times the diameter of the emitter hole It is characterized by being. If the diameter of the emitter hole exceeds 3 μm, it becomes difficult to produce a mesh structure, and if it is less than 0.5 μm, the device cost becomes too high. If the thickness of the insulating layer is less than twice, the electric field leaks from the emitter hole and it is difficult to apply the electric field to the emitter. If the thickness exceeds five times, the aperture ratio of the through hole needs to be set low in order to maintain the strength of the insulating layer. It is. The emitter is preferably made of graphite nanofiber or carbon nanotube. Furthermore, the size of the display element is in the range of 50 μm × 50 μm to 1000 μm × 1000 μm. If it is less than 50 μm × 50 μm, the device cost becomes too high, and if it exceeds 1000 μm × 1000 μm, it becomes too large for use in, for example, a flat panel display (FPD).

The method for manufacturing a cold cathode display device according to the present invention includes a step of sequentially forming a cathode electrode layer, an insulating layer, and a gate electrode layer on a lower substrate, a resist pattern is formed on the gate electrode layer, and then etching to form an emitter hole. Forming a gate electrode layer having a mesh structure, forming a cavity penetrating through the emitter hole to the insulating layer below the emitter hole by isotropic etching, and the cathode in the cavity A cathode part is produced by a step of forming an emitter on the exposed surface of the electrode layer, and then the cathode part and an anode part composed of a phosphor layer, an anode electrode layer and an upper substrate are connected to the outer periphery of the display element. via a support body provided in part Ri together in the method for manufacturing a cold cathode display device for producing a cold cathode display device, said cavity In the step of forming, to form a single through-hole in communication as the cavity, at least one therein cavity, that preferably performs isotropic etching so as to include a post comprising a plurality of said insulating layer Features.

  According to the field electronic display element of the present invention, it is easy to manufacture, has a display performance with little variation, can display a large area, and does not deform the gate electrode. As a result, the display color uniformity in the display elements is improved, and variations between elements are also suppressed, so that high-definition color display can be achieved.

  As described above, the present invention relates to a field electron emission display element and a manufacturing method thereof, and more particularly to a structure of a field electron emission display element using a carbon-based emitter.

  An embodiment of a cold cathode display device according to the present invention will be described with reference to FIGS.

  FIG. 1A is a plan view showing a mesh-like gate electrode structure of a display element, and FIG. 1B is a cross-sectional view showing the structure of the display element 1 taken along line XX in FIG. FIG.

  As shown in FIG. 1, a cathode electrode layer 12 is provided on the surface of the lower substrate 11, and an insulating layer 13 is provided on the cathode electrode layer 12. A plurality of hollow through holes 14 are provided in the insulating layer 13, and a plurality of emitters 15 formed on the exposed cathode electrode layer 12 are provided in each through hole. A gate electrode layer 16 is formed on the insulating layer 13, and this gate electrode layer has a mesh structure having an emitter hole 17 at least immediately above each emitter 15. That is, a plurality of through holes 14 are uniformly arranged in the display element 1, and a plurality of emitters 15 are uniformly arranged in each through hole. The emitter 15 is formed so as not to contact the gate electrode layer 16 and the insulating layer 13.

  When a carbon-based emitter is used as the emitter 15, a catalyst layer is usually used as a growth starting point for the formation of a carbon-based emitter by chemical vapor deposition or the like. It is arrange | positioned through the catalyst layer. One size of the display element 1 that emits predetermined light is defined by a rib 18 that is a support provided on the gate electrode layer 16, and the display element 1 is in a space above the gate electrode layer surrounded by the rib. A phosphor layer 19 that determines the emission color of is arranged. The phosphor layer 19 is provided on the upper substrate 21 via the anode transparent electrode layer 20. The electrons emitted from the emitter 15 pass through the emitter hole 17 of the gate electrode layer 16 and enter the phosphor layer 19 to emit light.

  The diameter of the through hole 14 which is a kind of cavity in the structure shown in FIG. 1 is designed in consideration of mechanical strength in consideration of the thickness of the gate electrode layer 16. It is preferable that the number density of the emitter holes 17 in each through hole 14 is uniform in one display element 1. As the number density of the emitter holes 17 in each through hole 14 is higher, the variation in the amount of electron emission from the emitter 15 between the through holes is suppressed, which is a more preferable mode.

  In the display element 1, the total aperture ratio of the through holes 14 provided in the insulating layer 13 is preferably in the range of 20% to 70% based on the total surface area of the insulating layer. When the aperture ratio is within this range, the uniformity of the display color is easily realized and the gate electrode layer is not deformed. In the form of FIG. 1, the mesh-like portion of the gate electrode layer 16 located on the through hole 14 is supported by the insulating layer 13 on the outer periphery of the through hole and maintains its shape against its own weight. It is preferable not to increase the aperture ratio. Therefore, in order to increase the light emission luminance of the display element 1, the aperture ratio of the through hole is not increased, that is, the diameter of the through hole 14 is not increased, but the number of the through holes in the display element is increased. It is preferable to carry out with.

  In the process of forming the structure shown in FIG. 1B, after forming the emitter hole 17 in the gate electrode layer 16, the through hole 14 is provided in the insulating layer under the gate electrode layer by means such as isotropic etching. Needless to say, when using the process, it is necessary to pay attention to the setting of the aperture ratio and the management of etching conditions so that the through-holes that should be spaced apart from each other are not communicated on the side surface by overetching in order to maintain the strength of the crosslinked structure.

  The diameter of the emitter hole 17 is preferably in the range of 0.5 μm to 3 μm, and it is naturally preferable to unify within the display element. The thickness of the insulating layer 13 is preferably in the range of 2 to 5 times the emitter hole diameter. When the thickness of the insulating layer is within this range, a satisfactory electric field can be applied to the emitter and the aperture ratio of the through hole can be increased. In the step of providing a through hole in the insulating layer by means such as the above-described isotropic etching, it is needless to say that the setting of the aperture ratio needs to be more careful because the side over etching proceeds as the thickness of the insulating layer increases. .

  2A and 2B show another embodiment different from the field electron emission display device shown in FIG. FIG. 2A is a plan view showing a mesh-like gate electrode structure in the display element, and FIG. 2B shows a structure of the display element 1 ′ viewed from the line XX in FIG. It is sectional drawing. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  Referring to FIG. 2, the insulating layer 13 formed on the lower substrate 11 via the cathode electrode layer 12 has a support 22 (support made of an insulating layer) that supports the gate electrode layer 16 together with the outer peripheral portion of the display element 1 ′. ) Is provided, and a plurality of emitters 15 formed on the exposed cathode electrode layer 12 are uniformly arranged in the cavity. In other words, a cavity as one through hole is provided over substantially the entire insulating layer (substantially the entire display element), and the gate electrode layer 16 on the insulating layer 13 is formed on the outer peripheral portion of the display element ( In other words, it is supported by the outer peripheral portion of the insulating layer) and the column 22 made of the inner insulating layer. Similar to the structure shown in FIG. 1, the gate electrode layer 16 has a mesh structure having an emitter hole 17 at least immediately above each emitter 15, and the emitter 15 does not contact the gate electrode layer 16 and the insulating layer 13. It is formed as follows.

  When a carbon-based emitter is used as the emitter 15, as described above, since the catalyst layer is usually used as a growth starting point for the formation of a carbon-based emitter by chemical vapor deposition or the like, although not shown, It is disposed via a catalyst layer on the cathode electrode layer 12. One size of the display element 1 that emits predetermined light is defined by a rib 18 that is a support provided on the gate electrode layer 16, and the display element 1 is in a space above the gate electrode layer surrounded by the rib. A phosphor layer 19 that determines the emission color of is arranged. The phosphor layer 19 is provided on the upper substrate 21 via the anode transparent electrode layer 20 as in the case of FIG. The electrons emitted from the emitter 15 pass through the emitter hole 17 of the gate electrode layer 16 and enter the phosphor layer 19 to emit light.

  Also in the structure shown in FIG. 2, the aperture ratio of the cavity 23 provided in the insulating layer 13 in the display element 1 ′ is 20% to 70 based on the total surface area of the insulating layer for the same reason as in the structure shown in FIG. 1. % Is preferable. In the structure of FIG. 2, the mesh-like portion of the gate electrode layer 16 located on the cavity 23 is supported by the insulating layer 13 at the outermost periphery of the cavity and the supporting pillar 22 including the insulating layer, and maintains its shape against its own weight. is doing. Therefore, in order to increase the light emission luminance of the display element 1 ′, it is preferable to reduce the diameter of the columns 22 included in the cavity 23 and increase the number of columns uniformly distributed in the display elements. Also in this structure, the diameter of the emitter hole 17 is preferably in the range of 0.5 μm to 3 μm, and it is naturally preferable to unify within the display element. The thickness of the insulating layer 13 is preferably in the range of 2 to 5 times the emitter hole diameter for the same reason as described in the case of FIG.

In the above embodiment, the substrate may be any substrate that is normally used in a display element. For example, a substrate made of glass, silicon, or ceramic (for example, STO or BTO) can be used. The cathode electrode layer material may be any metal or alloy that is usually used as a cathode electrode material. For example, a metal selected from Cr, Mo, Cu, W, Al, and Nd or an alloy containing at least one of these metals. Can be used. The insulating layer material may be any material that is normally used as an insulating layer, and for example, SiO ₂ or zirconia can be used. The gate electrode layer may be any metal or alloy that is usually used as a gate electrode layer, for example, a metal selected from Cr, Pd, Mo, Nd, Cu, W, and Al, or an alloy containing at least one of these metals. Can be used. The catalyst layer material may be any metal or alloy that is usually used as a catalyst material in the chemical vapor deposition method. For example, any one of Fe, Co, and Ni, or Invar, Inconel, Hastelloy, Harbor (Co Alloys such as / Cr / Ni / W / Mo / Mn / C / Be / F) can be used. Further, as the emitter material, for example, a material usually used as a carbon-based emitter material, preferably a material such as graphite nanofiber or carbon nanotube can be used. The production process of the carbon-based emitter is not particularly limited. For example, the graphite nanofiber can be produced through a normal process by chemical vapor deposition using a known carbon feedstock, hydrogen gas, and a catalyst. it can.

  According to the present invention, as described above, the gate electrode layer having a mesh structure is supported by the insulating layer and can maintain its shape even on the through hole or the cavity. Thus, a display element having a predetermined shape and size can be configured.

  According to the present invention, the size of the display element is not particularly limited. For example, the display element generally has a size of 50 μm × 50 μm to 1000 μm × 1000 μm, preferably 80 μm × 80 μm to 120 μm × 120 μm, and is shown in FIG. As described above, when a matrix is arranged in combination with the RGB phosphor layers and each element emits light under a predetermined control, a very high-definition color display can be performed.

  Next, the present invention will be described in detail by way of examples.

  A cathode part having a mesh-like gate electrode structure shown in FIG. 5 was produced according to the production process of the cathode part of the display element according to the present invention shown in FIGS. 4 and 5, the same components as those in FIG. 1 are denoted by the same reference numerals.

First, after forming a predetermined patterned cathode electrode layer 12 made of a Cr thin film having a thickness of 200 nm on the surface of the lower glass substrate 11, an insulating layer 13 made of a SiO ₂ thin film having a thickness of 5 μm is deposited on the entire substrate, Subsequently, a gate electrode layer 16 made of a Cr thin film having a thickness of 300 nm was formed on the insulating layer (FIG. 4A).

  Thereafter, a resist pattern 24 having a thickness of 1.5 μm is formed on the gate electrode layer 16 using a photoresist (FIG. 4B), and then a predetermined number of φ2 μm emitter holes 17 are formed by etching. A gate electrode layer 16 having a mesh structure was obtained (FIG. 4C). After cleaning the substrate while leaving the resist pattern 24, isotropic etching is performed on the insulating layer 13 below the emitter hole through the emitter hole 17 under normal conditions using BHF (buffered hydrofluoric acid) as an etchant. The through hole 14 was provided in the insulating layer (FIG. 4D). In this case, as shown in FIG. 5, in the gate electrode layer 16 corresponding to the display size (100 μm × 100 μm) of the display element, regions A (through holes) of φ20 μm are uniformly arranged at nine locations. Each of these was provided with 13 emitter holes in a lattice shape at a pitch of 4 μm. In this example, in the display element having a display size of 100 μm × 100 μm, the opening ratio of the insulating layer by all the through holes 14 was about 27%.

  Subsequently, the substrate is washed while leaving the resist pattern 24 on the gate electrode layer 16, and then the cathode electrode layer exposed in the through hole 14 directly below the emitter hole 17 is formed by sputtering Fe on the substrate. An Fe catalyst layer on which the emitter hole arrangement pattern was projected was formed on 12 with a thickness of about 50 nm (FIG. 4E).

Thereafter, the Fe layer adhered on the resist pattern 24 was removed together with the resist lift-off process. After cleaning the substrate on which the catalyst layer has been formed again, using a mixed gas of CH ₄ and H ₂ with a substrate temperature of 550 ° C. and a flow rate ratio of 1: 2 in the plasma CVD apparatus, the pressure is 0. 2.45 GHz. Carbon nanotubes were grown vertically on the cathode electrode layer 12 immediately below the emitter hole 17 by chemical vapor deposition under the condition of a growth time of 20 minutes at 1 Pa (FIG. 4F).

  In this way, a cathode portion was produced in which a plurality of emitters 15 composed of carbon nanotubes oriented vertically on the cathode electrode layer 12 were formed in the holes of the through holes 17. When the cross section of the obtained cathode part was observed with an electron microscope, it was observed that the carbon nanotubes were uniformly growing vertically in each through hole.

  Thereafter, a rectangular rib (18 in FIG. 1) forming the outer shape of the display element is provided on the gate electrode layer 16, and the cathode portion obtained as described above, the transparent electrode layer, and the phosphor layer are laminated. As a display element, an anode part provided on the upper glass substrate was bonded with a rib having a height of 500 μm so that the phosphor layer opposed to the gate electrode layer.

  A cathode part having a mesh-like gate electrode structure shown in FIG. 5 was prepared in the same manner as in Example 1 in accordance with the manufacturing process of the cathode part of the display element according to the present invention shown in FIG. However, as shown in FIG. 4E, an Fe catalyst layer on which the emitter hole arrangement pattern was projected was formed on the cathode electrode layer 12 exposed in the through hole 14 immediately below the emitter hole 17 with a thickness of about 50 nm. Thereafter, graphite nanofibers were grown not by plasma CVD but by thermal CVD.

That is, the Fe layer adhered on the resist pattern 24 is removed together with the resist lift-off process, and the substrate on which the catalyst layer is formed is washed again, and then the substrate temperature is 550 ° C. and the flow rate ratio is 1: 1 in the thermal CVD apparatus. A graphite nanofiber was grown on the cathode electrode layer 12 directly under the emitter hole 17 by chemical vapor deposition using a mixed gas of CO and H ₂ at a pressure of 0.1 MPa and a growth time of 20 minutes. In this way, a cathode portion was produced in which a plurality of emitters composed of graphite nanofibers oriented on the cathode electrode layer were formed in the holes of each through hole. When a cross section of the obtained cathode portion was observed with an electron microscope, it was observed that the cathode portion grew uniformly in a spaghetti-like state (that is, a curled state) in each through hole.

Thereafter, in the same manner as in Example 1, a rectangular rib forming the outer shape of the display element was provided on the gate electrode layer, and the cathode portion obtained as described above, the transparent electrode layer, and the phosphor layer were laminated. As a display element, an anode portion provided on the upper glass substrate was bonded with a rib so that the phosphor layer faced the gate electrode layer.
(Comparative Example 1)

  A cathode part having the gate electrode structure shown in FIG. 8 was manufactured according to the manufacturing process of the cathode part of the display element shown in FIGS. FIG. 9 shows a cross-sectional view of the obtained cathode part. 7 to 9, the same components as those in FIGS. 4 and 5 are denoted by the same reference numerals.

  Although the arrangement of the emitter holes is different from that in Example 1, the formation process of the cathode portion was performed according to Example 1. However, an independent through hole 27 is provided in the insulating layer 13 for each emitter hole 17. The size of the formed through hole was about 4 μm, and the total aperture ratio of the through hole was about 12% based on the total surface area of the insulating layer 13. After the emitter 26 is formed in the through hole 27, the anode portion provided on the upper glass substrate as a set of a transparent electrode layer for the anode and the phosphor layer laminated, the phosphor layer facing the gate electrode layer Thus, a display element was configured by bonding.

  When comparing the display element obtained in Example 1 and the display element of Comparative Example 1, the display element of Example 1 has higher emission uniformity within the light emission range than the display element of Comparative Example 1. In addition, both the variation between elements and the variation for each substrate when many were formed on the same substrate were smaller than those of the display element of Comparative Example 1. When the electron emission performance for each emitter was measured and verified, the display element of Example 1 showed less variation in performance than the display element of Comparative Example 1.

  A cathode portion having a mesh-like gate electrode structure shown in FIG. 6 was manufactured according to the manufacturing steps of the cathode portion of the display element according to the present invention shown in FIGS.

First, in accordance with the description in Example 1, on the surface of the lower glass substrate 11, a cathode electrode layer 12 made of a Cr thin film having a thickness of 200 nm, an insulating layer 13 made of a SiO ₂ thin film having a thickness of 5 μm, and a Cr thin film having a thickness of 300 nm are formed. A gate electrode layer 16 was sequentially formed. Thereafter, a resist pattern 24 having a thickness of 1.5 μm was formed on the gate electrode layer 16, and a predetermined number of φ2 μm emitter holes 17 were formed by an etching process to form a mesh-structured gate electrode layer 16. In this case, the formation region of the emitter hole 17 was a region B ′ shown in FIG. 6, and a gate electrode layer having a mesh structure different from that in Example 1 was formed.

  That is, 387 emitter holes are formed in 4 μm in the region B ′ excluding the φ20 μm region A ′ (9 locations) uniformly arranged in the gate electrode layer 16 corresponding to the display size (100 μm × 100 μm) of the display element. It was provided in a grid pattern with a pitch.

  Next, after cleaning the substrate while leaving the resist, isotropic etching is performed under normal conditions on the insulating layer 13 under the emitter hole through the emitter hole 17 using BHF as an etching solution. One penetrating cavity (corresponding to 23 in FIG. 2B) was provided in the insulating layer so that an insulating layer having a diameter of about 20 μm was left as a support 22 in A ′. In this example, in the display element having a display size of 100 μm × 100 μm, the aperture ratio of the cavity was about 69% of the total surface area of the insulating layer.

  Subsequently, in the same manner as in Example 1, a catalyst layer made of Fe on which the emitter hole arrangement pattern was projected was formed with a thickness of about 50 nm on the cathode electrode layer exposed in the cavity immediately below the emitter hole.

  Next, the resist pattern with the Fe layer adhered was removed together with the lift-off process. After cleaning the substrate on which the catalyst layer was formed, carbon nanotubes were vertically aligned on the cathode electrode layer immediately below the emitter hole by chemical vapor deposition in a plasma CVD apparatus under the same conditions as in Example 1. Multiple emitters were formed in the cavity.

  When the cross section of the cathode part thus obtained was observed with an electron microscope, it was observed that the carbon nanotubes were uniformly grown vertically in the cavity.

  Thereafter, a rectangular rib forming the outer shape of the display element is provided on the gate electrode layer, and the upper glass substrate as a set in which the cathode portion obtained as described above, the transparent electrode layer for the anode, and the phosphor layer are laminated. A display element was configured by bonding the anode portion provided on the substrate with a rib having a height of 500 μm so that the phosphor layer faces the gate electrode layer.

  When the display element obtained in Example 3 and the display element of Comparative Example 1 are compared, the display element of Example 3 is similar to Comparative Example 1 in terms of light emission uniformity within the light emission range as in Example 1. The display element was higher than that of the display element, and both the element-to-element variation and the substrate-to-substrate variation when formed in large numbers on the same substrate were smaller than those of the display element of Comparative Example 1. Since the number of emitters was larger than that in Example 1, the evaluation result in the case where the gate voltage was lowered and the luminance was equivalent to that in Example 1 was also inferior to that in Example 1.

  In the above embodiment, a glass substrate is used as the substrate, but a substrate made of silicon or the like can be used, and Cr is used as the cathode electrode layer material. However, Mo, Cu, W, Al, Nd, etc. can also be used. Although Cr was used as the gate electrode layer, Pd, Mo, Nd, Cu, W, and Al can also be used. Further, Fe is used as the catalyst layer material, but Co, Ni, Invar, Inconel, Hastelloy, Harbor, and the like can also be used.

  According to the present invention, it is possible to provide a display element structure that is easy to manufacture, has little variation in display performance, can display a large area, and has no deformation of the gate electrode layer by chemical vapor deposition. Therefore, the present invention can be used in the field of display elements using an emitter formed by chemical vapor deposition.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a structural diagram schematically showing one embodiment of the structure of a cold cathode display element according to the present invention, wherein (A) is a plan view of a mesh-like gate electrode structure, and (B) is a structure of the display element. FIG. FIG. 2 is a structural diagram schematically showing another embodiment of the structure of the cold cathode display element according to the present invention, in which (A) is a plan view of a mesh-like gate electrode structure, and (B) is a structure of the display element. FIG. The top view explaining the element arrangement | sequence of a color display apparatus. FIG. 3 is a process diagram showing a process for manufacturing a cathode portion of a cold cathode display element in Example 1. 2 is a plan view schematically showing a mesh-like gate electrode structure obtained in Example 1. FIG. FIG. 6 is a plan view schematically showing a mesh-like gate electrode structure obtained in Example 2. FIG. 5 is a process diagram showing a manufacturing process of a cathode portion of a conventional cold cathode display element in Comparative Example 1. The top view which shows typically the gate electrode structure of the cold cathode display element obtained by the comparative example 1. FIG. Sectional drawing which shows typically the structure of the cathode part of the cold cathode display element obtained by the comparative example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cold cathode display element 11 Substrate 12 Cathode electrode layer 13 Insulating layer 14 Through-hole 15 Emitter 16 Gate electrode layer 17 Emitter hole 18 Rib 19 Phosphor layer 20 Transparent electrode layer 21 Substrate 22 Support (insulating layer) 23 Cavity 24 Resist pattern 25 Catalyst layer 26 Carbon nanotube 27 Through hole

Claims (10)

A cathode electrode layer formed on the lower substrate; a gate electrode layer formed above the cathode electrode layer; an insulating layer having a penetrating cavity provided between the cathode electrode layer and the gate electrode layer; An emitter provided on the exposed surface of the cathode electrode layer in the cavity, a phosphor layer provided on the gate electrode layer, an anode electrode layer provided on the phosphor layer, and an upper substrate In a cold cathode display device comprising:
The cavity includes one through-hole and includes a support column including at least one insulating layer therein, and a plurality of emitters are uniformly provided in the cavity, and the gate electrode layer is formed of the plurality of emitters. A cold cathode display element comprising a mesh structure having an emitter hole at least at an individual upper position. Cold cathode display device according to claim 1 in which the aperture ratio of the cavity, characterized in that in the range of 20% to 70% in the insulating layer total surface area criteria. Cold cathode display device according to claim 1 or 2, wherein the gate electrode layer, characterized in that it is supported by the strut made of an insulating layer enclosing. A cathode part comprising the lower substrate, cathode electrode layer, gate electrode layer, insulating layer and emitter, and an anode part comprising the phosphor layer, anode electrode layer and upper substrate are provided on the outer periphery of the display element. cold cathode display device according to any one of claims 1 to 3, characterized in that they are attached to each other via the support. It said cavity is a cold cathode display device according to any one of claims 1 to 4, characterized in that which is formed by etching after formation of a gate electrode layer having the mesh structure. The diameter of the emitter hole, cold cathode display device according to any one of claims 1 to 5, characterized in that it is 3μm or less. The thickness of the insulating layer, a cold cathode display device according to any one of claims 1 to 6, characterized in that 2 to 5 times the diameter of the emitter hole. It said emitter, cold cathode display device according to any one of claims 1 to 7, characterized in that it consists of graphite nanofiber or carbon nanotube. Cold cathode display device according to any one of claims 1 to 8, characterized in that the size of the display device is in the range of 50μm × 50μm~1000μm × 1000μm. A step of sequentially forming a cathode electrode layer, an insulating layer, and a gate electrode layer on the lower substrate, and after forming a resist pattern on the gate electrode layer, an emitter hole is formed by etching to form a gate electrode layer having a mesh structure Forming a cavity, forming a cavity penetrating the insulating layer below the emitter hole by isotropic etching through the emitter hole, and forming an emitter on the exposed surface of the cathode electrode layer in the cavity. The cathode part is manufactured by a process, and then the cathode part and the anode part composed of the phosphor layer, the anode electrode layer, and the upper substrate are bonded together via a support provided on the outer peripheral part of the display element. In the method for producing a cold cathode display element for producing a cold cathode display element,
In the step of forming the cavity, one through hole communicated as the cavity is formed, and isotropic etching is performed so as to include at least one column made of the insulating layer inside the cavity. A method for producing a cold cathode display element.

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