TW201142895A - Field emission device - Google Patents

Abstract

The present invention relates to a field emission device. The field emission device includes an insulative substrate, an electron pulling electrode, a secondary electron emission layer, a cathode, an electron emission layer, and a gate electrode. The electron pulling electrode is located on a surface of the insulative substrate. The secondary electron emission layer is located on a surface of the electron pulling electrode. The cathode is located apart from the electron pulling electrode via a first insulative layer. The electron pulling electrode is located between the cathode and the insulative substrate. At least a part of the cathode is opposite to the electron pulling electrode. The cathode has an opening as an electron outputting element. The electron emission layer is located on a surface of the cathode opposite to the electron pulling electrode. The gate electrode is located apart from the cathode. The cathode is located between the gate electrode and the electron pulling electrode.

Description

201142895 VI. Description of the Invention: [Technical Field of the Invention] [0001] The present invention relates to a field emission device. [Previous sacral surgery] [0002] Field emission devices are important components of field emission electronics such as field emission displays. [0003] A field emission device in the prior art generally includes an insulating substrate 'a cathode electrode disposed on the insulating substrate; a plurality of electron emitters disposed on the cathode electrode; and a first insulating layer disposed on the insulating substrate Engaging the layer, the first insulating isolation layer has a through hole through which the electron emitter is exposed so that electrons emitted from the electron emitter are emitted through the through hole; and an anode electrode, the anode electrode and The cathode electrodes are spaced apart. When the field emission device is operating, a high potential is applied to the anode electrode and a low potential is applied to the cathode electrode. Therefore, electrons emitted from the electron emitter pass through the through hole. [0004] However, electrons emitted by the electron emitter collide with free gas molecules in the vacuum, thereby ionizing the gas molecules to generate ions. Moreover, the ions move toward the cathode electrode at a low potential. Since the electron emitter of the field emission device is exposed through the through hole, the electron emitter is easily bombarded by the ion, thereby causing damage to the electron emitter. [Invention] [0005] In view of this, A field emission device that can effectively prevent ion bombardment of an electron emitter is necessary. 099116607 Form No. A0101 Page 4/36 Page 0992029539-0 201142895 [0007] [0007] A field emission device comprising: an insulating substrate; an electron extraction electrode * the electron extraction electrode is disposed at a surface of the insulating substrate; a secondary electron emission layer disposed on a surface of the electron extraction electrode; a cathode electrode disposed at a distance from the electron extraction electrode through a first insulating isolation layer The electron extraction electrode is disposed between the cathode electrode and the insulating substrate, the cathode electrode has a surface at least partially disposed opposite the electron extraction electrode, the cathode electrode has a first opening, the first opening defines an electron emission An electron emission layer disposed on a surface of the cathode electrode facing the electron extraction electrode; a gate electrode, the gate electrode is insulated from the cathode electrode, and the cathode electrode is disposed at the electron extraction Between the pole and the gate electrode. A field emission device comprising: a field emission device comprising: an insulating substrate; an electron extraction electrode disposed on a surface of the insulating substrate; a secondary electron emission layer, the secondary electron emission a layer disposed on a surface of the electron extraction electrode; a cathode electrode disposed at a distance from the electron extraction electrode through a first insulating isolation layer disposed between the cathode electrode and the insulating substrate, the cathode electrode Having a surface at least partially disposed opposite the electron extraction electrode, the cathode electrode having a first opening defining an electron emission portion; an electron emission layer disposed on the cathode electrode facing the electron a portion of the surface of the electrode is disposed; an anode electrode, the anode electrode is spaced apart from the cathode electrode, and the cathode electrode is disposed between the electron extraction electrode and the anode electrode. Compared with the prior art, since the electron emission portion is formed on the cathode electrode, 099116607 Form No. 1010101 Page 5 / Total 36 Page 0992029539-0 201142895 The electron emission end of the electron emitter is not exposed through the electron emission portion, so when the electron When the electrons emitted by the emitter collide with free gas molecules in the vacuum to generate ions to move toward the electron extraction electrode, the ions do not bombard the electron emitter, thereby making the electron emitter have a long life. [Embodiment] [0011] The field emission device provided by the embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The field emission device can include one or more cells. The embodiment of the present invention is described by taking only one unit as an example. Referring to FIG. 1 to FIG. 3, a first embodiment of the present invention provides a field emission device 100 including an insulating substrate 110, a first insulating isolation layer 112, a cathode electrode 114, an electron emission layer 116, and an electron extraction. The electrode 118 has a secondary electron emission layer 12'' and a second insulating isolation layer ΐ2ι and a gate electrode 122. The insulating substrate 11 has a surface, and the electron extraction electrode 118 ax is placed on the surface of the insulating substrate 110, and the secondary electron emission layer 12 is disposed on the electron. The extraction electrode 118 is away from the surface of the insulating substrate 11A. The cathode electrode 114 is spaced apart from the electron extraction electrode 118 by a first insulating spacer 112, and the electron extraction electrode 118 is disposed between the cathode electrode 114 and the insulating substrate 11A. The cathode electrode 114 defines a first opening 1140 as an electron emitting portion. The first opening 1140 of the cathode electrode 14 faces the electron extraction electrode u 8 , that is, the electron emission portion is disposed opposite to the electron extraction electrode 118. The cathode electrode 114 has a surface, and at least a portion of the surface faces the electron extraction electrode 118. The electron emission layer U6 is disposed on the cathode electrode 099116607 Form No. A0101, page 6 / page 36 0992029539-0 201142895, and the electronic extraction electrode 118 faces a portion of the surface disposed. Preferably, the electron emission layer 116 is disposed at a position where the surface of the cathode electrode 114 is close to the electron emission portion. The gate electrode 122 is spaced apart from the cathode electrode 通过 by the second insulating isolation layer 121. The electrons emitted from the electron emission layer 116 bombard the secondary electron emission layer 12 to generate secondary electrons. The secondary electrons emitted from the secondary electron emission layer 120 are emitted through the electron emission portion by the gate electrode. [0012] The material of the insulating substrate 110 may be tantalum, glass, ceramic, plastic or polymer. The shape and thickness of the insulating substrate 110 are not limited and can be selected according to actual needs. Preferably, the shape of the insulating substrate bird 0 is circular, square or rectangular. In the present embodiment, the insulating substrate 1 is a square glass plate having a length of 10 mm and a thickness of 1 mm. [0013]

The electron extraction electrode 118 is a conductive layer, and the thickness and size thereof can be selected according to actual needs. The material of the electron extraction electrode 118 can be pure gold eyebrow, alloy, oxidized sulphur tin or conductive paste, etc. When the insulating substrate 110 is a germanium, the electron extracting electrode 118 may be a doped layer. In this embodiment, the electron extraction electrode 118 is a circular film having a thickness of 20 μm. The Ming film is deposited on the surface of the insulating substrate 110 by a magnetron sputtering method. [0014] The material of the secondary electron emission layer 120 includes magnesium oxide (Mg〇), beryllium oxide (BeO), magnesium fluoride (Mg%), neodymium fluoride (BeF), antimony oxide (CsO), and antimony oxide. One or more of (β3〇), the thickness and the smallness can be selected according to actual needs. The secondary electron emission layer 12 is formed on the surface of the electron extraction electrode 118 by a method such as coating, electron beam evaporation, thermal evaporation, or fundamental control. It can be understood that the secondary electric 099116607 form Α Α 0101 7th / 36 pages 0992029539-0 201142895 The surface of the sub-emissive layer 120 may also be formed with a concave-convex structure to increase the area of the secondary electron-emitting layer 120, which may be improved Secondary electron emission efficiency. In this embodiment, the secondary electron emission layer 120 is a circular yttrium oxide layer having a thickness of 20 μm. [0015] The cathode electrode 114 may be a conductive layer or a conductive substrate, and the material thereof may be metal, alloy, indium tin oxide (ITO) or conductive paste. The thickness and size of the cathode electrode 114 can be selected according to actual needs. At least a portion of the surface of the cathode electrode 114 is disposed to face the secondary electron emission layer 120. The cathode electrode 114 has a first opening 1140 as an electron emitting portion. Specifically, the cathode electrode 114 may be a layered structure having through holes or a plurality of strip structures disposed at a distance. The first opening 1140 may be a space between the through holes of the cathode electrode 114 or a strip structure disposed at a certain distance. In this embodiment, the cathode electrode 114 is a circular aluminum conductive layer and has a through hole at the center thereof as an electron emitting portion. [0016] The first insulating isolation layer 112 is disposed between the cathode electrode and the electron extraction electrode for insulating the cathode electrode and the electron extraction electrode. The material of the first insulating spacer 112 may be a resin, a thick film exposure adhesive, glass, ceramic, oxide, a mixture thereof or the like. The oxide includes cerium oxide, aluminum oxide, cerium oxide, etc., and its thickness and shape can be selected according to actual needs. The first insulating isolation layer 112 may be directly disposed on the surface of the insulating substrate 110 or may be disposed on the surface of the electron extraction electrode 118. The first insulating isolation layer 112 has a second opening 1120. Specifically, the first insulating spacer layer 2 may be a layered structure having a through hole, and the through hole is a second opening 1120, exposing secondary electrons 099116607 Form No. A0101 Page 8 / 36 pages 0992029539- 0 Emissive layer 120. The first insulating spacer 11 2 may also be a plurality of strip structures disposed at a certain distance, and the interval between the strip structures disposed at a certain distance is the second opening 1120. At least a portion of the cathode electrode 114 is disposed at the second opening 1120 of the first insulating isolation layer 112, and the second opening 1120 of the first insulating isolation layer 112 exposes a portion of the surface facing the second The electron emission layer 12 is set. The first opening 1140 of the cathode electrode 114 is at least partially overlapped with the second opening 1120 of the first insulating spacer. A portion of the first opening u4 交 overlapping the second opening 1120 serves as an electron emitting portion. Preferably, the first opening 1140 is completely disposed in the range of the second opening 1120. The first opening 1140 is an electron emitting portion. In the embodiment, the first insulating isolation layer 112 is a thickness of 1 μm. The annular SU-8 photoresist is disposed on the surface of the glass plate, and defines a circular through hole through which a part of the surface of the cathode electrode 114 faces the secondary electron emission layer 120. The through hole of the cathode electrode 14 is disposed in the range of the circular through hole of the first insulating spacer 112 as an electron emitting portion. The gate electrode 122 may be a metal grid, a metal piece, a thin indium tin oxide film, a knee or a conductive paste layer, or the like. The gate electrode 122 is disposed on the other surface of the second insulating isolation layer 121 opposite to the cathode electrode 114, that is, the second insulating isolation layer 121 is disposed between the gate electrode 122 and the cathode electrode 114. Specifically, the gate electrode 122 may be disposed at a position where the upper surface of the second insulating isolation layer 121 is close to the electron emission portion. When the gate electrode 122 is a grid, the town covers the electron exit portion. The gate electrode 122 can be prepared by screen printing, electroplating, chemical vapor deposition, magnetron sputtering, thermal deposition, etc., or the metal grid prepared in advance can be directly formed into a form No. A0101 page 9 / Total 36 pages 201142895 is placed on the second insulating isolation layer 12i. In this embodiment, the salient electrode 122 is a metal grid, and the gate electrode 122 extends from the surface of the second insulating spacer 121 to above the electron emitting portion, and the metal grid covers the electron emitting portion. It can be understood that the metal grid can also be coated.

The secondary electron-emitting material enhances the field emission current density of the field emission device (10). X

[0018] The material and formation method of the second insulating spacer 121 are the same as those of the first insulating spacer 112. The second insulating spacer 121 functions to insulate the cathode electrode 114 from the gate electrode. The cathode electrode 114 is disposed on a surface of the second insulating secret layer 121 adjacent to the electrical output electrode 118. The second insulating spacer 121 is a layered structure having a shape and size corresponding to the cathode Wei 114. The second insulating spacer 121 has a third open σ 1212 corresponding to the electron exit portion. The third opening 1212 at least partially overlaps the first opening (10) and the second opening 112G. The portion of the second opening 1212 overlapping the first opening 114 and the second opening 1120 is further disposed as an electron emitting portion. . In the embodiment, the second insulating isolation layer 121 has a through hole corresponding to the electron emission portion. The second insulating isolation layer 121 may be provided with a secondary electron emission material on the inner wall of the third opening 1212. That is, the surface of the second insulating spacer 121 close to the electron emitting portion may be provided with a secondary electron emitting material. At this time, the thickness of the second insulating isolation layer m may be made larger, such as 500 micro #10 gq micron, to improve the area of the secondary electron emission material. The second insulating isolation layer 121 is at the third opening 1212. A plurality of recess & structures may be formed on the inner wall to increase the area of the secondary electron emissive material. 099116607 Form No. A0101 Page 10/36 Page 0992029539-0 201142895 [0019] The electron emission layer 116 is disposed on a portion of the surface of the cathode electrode ι 4 facing the secondary electron emission layer 120, and the electron emission layer 116 faces the surface > a Electron emission layer 120 is provided. Preferably, the electron emission layer 11 6 is disposed at a position where the surface of the cathode electrode 114 is close to the electron emission portion. The electric hand emitting layer 116 includes a plurality of electron emitters 1162, such as carbon nanotubes, carbon nanotubes, or nanowires. Each of the electron emitters 1162 has an electron emitting end 1164, and the electron emitting end 11 64 is disposed toward the top electron emitting layer 120. The thickness and size of the electron emission layer 116 can be selected according to actual needs. Further, the surface of the electron emission layer 116 may be provided with an anti-ion bombardment material to improve its stability and taste. The ion bombardment resistant material includes one or more of zirconium carbide, tantalum carbide, lanthanum hexaboride, and the like. In this embodiment, the electron emission layer 116 is a circular carbon nanotube slurry layer. The carbon nanotube slurry comprises a carbon nanotube, a low melting glass powder, and an organic vehicle. Among them, the organic carrier evaporates during the baking process, and the low-melting glass frit is grafted in the baking process and the carbon nanotubes are fixed on the surface of the cathode electrode U4. The outer diameter of the annular electron-emitting layer 116 is less than or equal to half of the secondary electron-emitting layer 120, and the inner diameter is equal to the radius of the electron-emitting portion. The distance between the electron-emitting end 64 of the electron-emitting body 1162 of the electron-emitting layer 116 and the surface of the secondary electron-emitting layer 120 with respect to the surface of the electron-emitting end 1164 is smaller than the mean free path of electrons and gas molecules to reduce ion-pair electron emission. Bombardment of body 1162. On the one hand, since the distance between the electron-emitting end U 64 and the surface of the secondary electron-emitting layer 120 with respect to the surface of the electron-emitting end 11 64 is smaller than the mean free path of electrons and gas molecules, the electrons emitted by the electron-emitting body 1162 are in the gas molecule (refers to the electron emission end 099116607 No. Α 0101 11th buy / 36 pages 0992029539-0 201142895 1164 and the gas molecules between the secondary electron emission layer i2 )) will first bombard the secondary electron emission layer 12 〇, thereby The electrons emitted by the enhanced electron emitter 1162 bombard the secondary electron emission layer 120. On the other hand, since the probability of electrons emitted from the electron emitter 11 62 colliding with the gas molecules is reduced, that is, the probability of ion generation of the gas molecules is also reduced, the electron emission end 11 64 and the secondary electron emission layer 120 are also reduced. The probability of generating ions between them is also reduced, thereby reducing the probability that the electron-emitting end 1164 is bombarded with ions in front. [0021] According to the theory of gas molecular motion, the mean free path between gas molecules and the mean free path between free electrons and gas molecules are shown by equations (1) and (2), respectively, at a certain pressure: [0022] ]

kT4ϊπά2Ρ (1)

[0024] wherein 'k = 1.38xl0 23J/K is a Boltzmann constant; τ is an absolute temperature; d is the effective diameter of the gas molecule; ρ is the gas pressure. Taking a nitrogen gas having a temperature of 300 K as an example, the average free path of air molecules is about 50 μm at a gas pressure of ιτ〇ΓΙ·, and the mean free path of free electrons and gas molecules is 283 μm. Therefore, if the electron emission end 099116607 form number A0101

Page 12 / 36 I 0992029539-0 201142895 11 64 In the case where the distance from the surface of the secondary electron emission layer 120 is sufficiently small, the field emission device 100 can operate in a low vacuum state without causing the electron emitter 1162 Damage. [0025] In the present embodiment, the distance between the electron-emitting end 1164 and the secondary electron-emitting layer 120 with respect to the surface of the electron-emitting end 1164 is 10 μm to 30 μm. Accordingly, the field emission device 100 can operate under a low vacuum condition of a pressure of up to 9 Torr to 27 Torr without causing damage to the emitter. When a better vacuum, such as a pressure drop of one order of magnitude down to ITorr, the collision of electrons with the gas molecules in the launch gap can be neglected, and the damage caused by the ion bombardment of the emitter can be neglected. It will be appreciated that the field emission device 100 can also operate in a high vacuum environment or an inert gas environment with more stable performance. Specifically, the specific structure of the field emission device 100 of the present embodiment is as follows. The first insulating isolation layer 112 is disposed on a surface of the insulating substrate 110, and the first insulating isolation layer 112 defines a second opening 1120 to expose a surface of the insulating substrate 110 through the second opening 1120. The electron extraction electrode 11 8 is disposed on a surface of the insulating substrate 110 exposed through the second opening 1120, and the thickness of the electron extraction electrode 118 is smaller than the thickness of the first insulating isolation layer 112. The secondary electron emission layer 120 is disposed on a surface of the electron extraction electrode 118 and electrically connected to the electron extraction electrode 118. The cathode electrode 114 is disposed on a surface of the first insulating isolation layer 112 and extends above the secondary electron emission layer 120. The cathode electrode 114 defines a first opening 1140 as an electron exit portion. The electron emission layer 116 is disposed on a surface of the cathode electrode 114 facing the secondary electron emission layer 120, and is electrically connected to the cathode electrode 114. The electron emission 099116607 Form No. A0101 Page 13 of 36 0992029539-0 201142895 The layer 116 is opposite and spaced apart from the secondary electron emission layer 120. The second insulating isolation layer 211 is disposed on a surface of the cathode electrode 114 away from the secondary electron emission layer 120, and the third opening 1212 of the second insulating isolation layer 121 is disposed corresponding to the electron emission portion. The gate electrode 122 is disposed on a surface of the second insulating spacer 121 and extends from a surface of the second insulating spacer 121 to an upper portion of the electron emitting portion to cover the electron emitting portion. [0027] When the field emission device 100 is in operation, the potential of the electron extraction electrode 118 is higher than the potential of the cathode electrode 114, and the potential of the gate electrode 122 is higher than the potential of the electron extraction electrode 118. In this embodiment, the cathode electrode 114 is maintained at a zero potential, a voltage of 100 volts is applied to the electron extraction electrode 118, and a voltage of 500 volts. _ is applied to the gate electrode 12 2 . The electron emitter 1162 emits electrons under the action of the voltage of the electron extraction electrode 118, and the electrons bombard the secondary electron emission layer 120 to cause the secondary electron emission layer 120 to emit secondary electrons. The secondary electrons emitted from the secondary electron emission layer 120 are emitted from the electron emission portion by the voltage of the gate electrode 122. [0028] The field emission device 100 has the advantage that since the electron emission portion is formed on the cathode electrode 114, the electron emission end 1164 of the electron emitter 1162 is not exposed through the electron emission portion, so when the electron emitter 11 62 is emitted When the electron collides with the free gas molecules in the vacuum to generate ions moving toward the electron extraction electrode 118, the ions do not bombard the electron emitter 1162, so that the electron emitter 1162 has a long life. The formation of an anti-ion bombardment material on the electron-emitting layer 116 can improve its stability and life. At the same time, since the secondary electron emission layer 120 is used, a large emission current can be obtained at a low emission voltage. Referring to FIG. 4, a first embodiment of the present invention provides a field emission device 100 099116607 Form No. A0101 Page 14 / Total 36 Page 0992029539-0 201142895 [0030] [0033] [0033] Ο [ [0035] The preparation method of the method includes the following steps: Step one, providing an insulating substrate 110. In this embodiment, the insulating substrate 110 is a square glass plate. In step two, an electron extraction electrode 118 is formed on a surface of the insulating substrate 110. The electron extraction electrode 118 can be prepared by screen printing, electroplating, chemical vapor deposition, magnetron sputtering or thermal deposition. In this embodiment, a layer is deposited as an electron extraction electrode 118 on the surface of the insulating substrate 110 by a magnetron emission killing method. In the third step, a secondary electron emission layer 120 is formed on the surface of the electron extraction electrode 118. The secondary electron emission layer 120 may be prepared by screen printing, electroplating, chemical vapor deposition, magnetron sputtering or thermal deposition. In the present embodiment, a layer of ruthenium oxide is formed on the surface of the electron extraction electrode 118 as a secondary electron emission layer 120 by surface coating. Step 4, forming a first insulating isolation layer 112 on the surface of the insulating substrate 110, the first insulating isolation layer 112 having a second opening 1120 such that the surface of the secondary electron emission layer 120 is exposed through the second opening 1120. The first insulating spacer layer 112 can be prepared by a method such as screen printing, silicone coating, coating or thick film process. In the present embodiment, a first insulating spacer 112 having a circular via hole is directly formed on the surface of the cathode electrode 114 by screen printing, so that the surface of the secondary electron emission layer 120 is exposed through the circular via hole. 099116607 Form No. 1010101 Page 15 / Total 36 Page 0992029539-0 201142895 [0038] Step 5, providing a cathode-threshold seven-electrode electrode plate (not shown) having a first opening 1140, + and A part of the surface of the cathode electrode plate forms an electron emission layer 116. [0039] The cathode electrode plate may be a rim substrate. The conductive substrate or the conductive layer is formed. [0040] In the embodiment, the method for preparing the cathode electrode plate includes the following steps. [0041] First, a second insulating isolation layer ΐ2ι is provided. The second insulating spacer j 21 may be a substrate or a strip having a through hole. In this embodiment, the second insulating isolation layer 121 is an annular glass plate, and the second insulating isolation layer 121 has a third opening. ^. Then, a cathode electrode 丨丨4 is formed at a position of the surface of the second insulating isolation layer 121 near the third opening 1212. [0044] The cathode electrode 114 may be prepared by a method such as silk printing, vacuum coating, or the like, or a metal piece may be directly disposed on the surface of the second insulating isolation layer 121. In this embodiment, a circular aluminum layer is deposited as a cathode electrode 114 on the surface of the second insulating isolation layer by magnetron sputtering, and the step electrode 114 is formed with a first opening corresponding to the third opening 1212. 〇U4〇, as an electron emission unit. [0045] The electron emission layer 116 may be prepared by a printing paste or chemical vapor deposition, de-equivalent method. In this embodiment, a ring of carbon nanotube paste is formed on the surface of the cathode electrode 114 by screen printing, and then the carbon nanotube layer is baked. The carbon nanotube slurry comprises a carbon nanotube, a low average ^ 099116607 Form No. A0101 Page 16 of 36 0992029539-0 201142895 [0046] Ο [0047]

[0049] 099116607 point glass powder and an organic vehicle. Wherein the organic vehicle evaporates during the baking process, the low-melting glass frit melts during the baking process and the carbon nanotubes are fixed to the surface of the cathode electrode 114. Further, the carbon nanotube electron-emitting layer 116 may be surface-treated by means of tape bonding and peeling to expose more carbon nanotubes. It is understood that the carbon nanotube electron-emitting layer 116 is peeled off by tape bonding so that the carbon nanotubes are exposed while being perpendicular to the surface of the secondary electron-emitting layer 12 . Further, an ion bombarding material such as zirconium carbide, carbonized bell, lanthanum hexaboride or the like may be formed on the electron emission layer 116 to improve stability and life. In this embodiment, a film of tantalum carbide is formed on the surface of the carbon nanotube by a method of controlling the machine. 1 step 6, assembling the cathode electrode plate to the other surface of the first insulating isolation layer 112 relative to the insulating substrate 110, so that the first opening 114〇 and the second opening 1120 are at least partially overlapped to define an electron emitting portion, and The electron emission layer 116 is disposed at least partially at the second opening 1120 of the first insulating isolation layer 112 and disposed facing the electron extraction electrode 51. The first opening η 4 阴极 of the cathode electrode 114 is disposed corresponding to the second opening 1120 of the first insulating spacer 112, and the first opening 丨14〇 is at least partially overlapped with the second opening 1120 to define an electron emitting portion. In this embodiment, the annular cathode electrode plate is directly disposed on the surface of the first insulating isolation layer 112 such that the first opening 114 is completely disposed within the range of the second opening 1120, and the electron emission layer 116 is at least Part of the surface is disposed facing the electron extraction electrode 118. It can be understood that when the cathode electrode plate is a strip body, at least two cathode electrode plates can be arranged in parallel at the first form number Λ 010] page 17 / 36 pages 〇卯 2029539 〇 201142895 surface of an insulating isolation layer 11 2 . A first opening 114 is defined between the spaced apart cathode electrode plates as an electron emitting portion. [0050] Step 7' is provided with a gate electrode 122 on the surface of the second insulating isolation layer 121 away from the electron extraction electrode 118. [0051] The gate electrode 122 can be prepared by screen printing, electroplating, chemical vapor deposition, magnetron sputtering, thermal deposition, etc. 'The metal grid prepared in advance can also be directly disposed on the second insulation. In the isolation layer 121, a metal grid is directly disposed and fixed on the surface of the second insulating isolation layer 121 in this embodiment. It can be understood that this step is an optional step. It is to be understood that the steps of the above-described method of manufacturing the field emission device 100 are not limited to the above-described order, and those skilled in the art can make adjustments according to actual needs. For example, the preparation method of the above field emission device 1〇〇 may include the following steps: [0053] Step 1 'provides a cathode electrode plate' having a first opening 1140 and dividing the cathode electrode plate 63⁄43⁄4 Forming an electron emission layer 116 on the surface 005 [0054] Step 2, forming a first insulating isolation layer 112 on the surface of the cathode electrode plate, the first insulating isolation layer 11 2 having a second opening 1120 such that the electron emission layer 116 passes through the first The two openings 1120 are exposed. [0055] Step three, providing an insulating substrate 110. [0056] Step 4, an electron extraction electrode 118 and a secondary electron emission layer 120 are sequentially formed on the surface of the insulating substrate 110. [0057] Step 5 'Assemble the insulating substrate 110 to the first insulating isolation layer 112 phase 099116607 Form No. A0101 Page 18 / Total 36 Page 0992029539-0 201142895 For the other surface of the insulating substrate 110, the first opening 1140 is made The second opening 1120 is at least partially overlapped to define an electron emitting portion, and such that the electron emission layer 116 is disposed at least partially at the second opening 1120 of the first insulating isolation layer 112 and disposed facing the electron extraction electrode 118. Referring to FIG. 5, a second embodiment of the present invention provides a field emission device 2A including an insulating substrate 21A, a first insulating isolation layer 212, a cathode electrode 214', and an electron emission layer 216. An electron extraction electrode 218, a secondary electron emission layer 220, a second isolation isolation layer 221, and a gate electrode 222. The structure of the field emission device 2A provided by the second embodiment of the present invention is substantially the same as that of the field emission device 1A according to the first embodiment of the present invention. The difference is that the surface of the secondary electron emission layer 220 is the same as the first An opposite opening 2140 has at least one first protrusion 2202, and a surface of the cathode electrode 214 opposite to the secondary electron emission layer 22 has at least one second protrusion 2142. The electron emission layer 216 is disposed on the surface of the at least one second protrusion 2142 and the electron emission end 2164 of the electron emitter 2162 is directed to at least the surface of the first protrusion 2202. [0059] The shape and size of the first protrusion 2202 and the second protrusion 2142 are not limited, and may be selected according to actual needs. It can be understood that when the cathode electrode 214 is a layered structure having a through hole, the first protrusion 22〇2 may be a taper, and the second protrusion 2142 is a surrounding first protrusion 22〇2. The annular protrusions, when the cathode electrode 214 is a plurality of spaced strip structures, the first protrusions 2202 and the second protrusions 2142 may be a pyramid extending along the strip structure. In this embodiment, the first protrusion 2202 is a cone pointing to the first opening 214A. The side of the second protrusion 2142 opposite to the first protrusion 2202 is parallel to the surface 099116607 of the first protrusion 22〇2, page 19/19, 0992029539-0 201142895. The electron emitter 2162 of the electron emission layer 216 extends perpendicularly to the surface of the first protrusion 2202. It is understood that the secondary electrons excited by the electrons emitted by the electron emitters striking the surface of the first protrusions 2202 are more easily emitted from the electron emitting portions by the gate electrodes 222. Referring to FIG. 6 , a third embodiment of the present invention provides a field emission device 3A including an insulating substrate 310, a first insulating isolation layer 312, a cathode electrode 314, and an electron emission layer 316'. The electron extraction electrode 318, the secondary electron emission layer 320, a second insulation isolation layer 321 and the surface electrode 322. The structure of the field emission device 3 提供 provided by the third embodiment of the present invention is substantially the same as that of the field emission device 1 提供 provided by the first embodiment of the present invention, and the difference is the thickness of the second insulating isolation layer 321 . The second insulating spacer 321 has a third opening 3212, and the inner wall of the third opening 3212, that is, the surface of the second insulating isolation layer 321 near the electron emitting portion is further provided with a secondary electron emitting material. And the size of the third opening 3212 gradually decreases in a direction away from the electron extraction electrode 3丨8, so that electrons emitted from the secondary electron emission layer 320 are more easily bombarded to the secondary electron emission material of the inner wall of the third opening 3212. The gate electrode 322 is a circular conductive layer. The gate electrode 322 can focus on electrons emitted from the secondary electron emission layer 320. Referring to FIG. 7, a fourth embodiment of the present invention provides a field emission device 4A including an insulating substrate 410', a first insulating isolation layer 412, a cathode electrode 414, and an electron emission layer 416. An electron extraction electrode 418, a secondary electron emission layer 420, a second insulation isolation layer 421, _ - a - a human electron dynode 424, a third insulation isolation layer 426, and a thumb electrode 422. The field emission device 10 of the fourth embodiment of the present invention has the same structure as the field emission device 100 provided by the first embodiment of the present invention. The structure of the field emission device 100 is the same as that of the first embodiment of the present invention. The difference between the second insulating isolation layer 421 and the gate electrode 422 further includes a secondary electron dynode 424 and a third insulating isolation layer 426. The gate electrode 422 and the secondary electron dynode 424 are insulated by the third insulating spacer 4 26 . The gate electrode 42 2 is a metal grid. [0062] Ο

The secondary electron dynode 424 is a conductive layer having a thickness greater than 5 Å micrometers and having a fourth opening 4240 corresponding to the first opening 4140. The inner wall of the fourth opening 4240, i.e., the secondary electron dynode 424, is adjacent to the surface of the electron-emitting portion, and is coated with a secondary electron-emitting material 4242 to further enhance the field emission current density of the field emission device 400. Further, the inner wall of the fourth opening 4240 may further form a plurality of concave and convex structures to increase the area of the coated secondary electron emission material 4242. When the field emission device 400 is in operation, the potential of the electron extraction electrode 418 is higher than the potential of the cathode electrode 414. The potential of the secondary electron dynode 424 is higher than the potential of the electron extraction electrode 518, and the potential of the gate electrode 422 is higher than two. The potential of the secondary electron dynode 424. It can be understood that the electrons emitted by the secondary electron emission 赝420 can bombard the secondary electron emission material 4242 on the surface of the secondary electron dynode 424 more strongly under the action of the secondary electron dynode 424 to excite the second. Secondary electrons. [0063] Referring to FIG. 8, a fifth embodiment of the present invention provides a field emission device 500 including an insulating substrate 510, a first insulating isolation layer 512, a cathode electrode 514, an electron emission layer 516, and an electron extraction. The electrode 518, a secondary electron emission layer 520, a second insulating isolation layer 521, a gate electrode 522 and an anode electrode 530. The fifth embodiment of the present invention provides 099116607 Form No. A0101 Page 21 of 36 0992029539-0 201142895

Between the electrodes 518, the electrode 514 is disposed on the anode electrode 53 and the electron is extracted. The gate electrode 522 is disposed between the anode electrode 53A and the cathode electrode 514. The anode electrode 530 is a conductive layer, and the material thereof may be indium tin oxide, metal, carbon nanotubes or the like. In this embodiment, the anode electrode 530 is an indium tin oxide transparent conductive layer. When the field emission device 500 is in operation, the potential of the electron extraction electrode 518 is higher than the potential of the cathode electrode 514, the potential of the gate electrode 522 is higher than the potential of the electron extraction electrode 8, and the potential of the anode electrode 530 is higher than that of the gate electrode 522. Potential. It will be understood that the gate electrode 522 is an optional structure. [0068] In summary, the present invention has indeed met the requirements of the invention patent, and the patent application is filed according to law. However, the above description is only a preferred embodiment of the present invention, and the scope of the patent application of the present invention is not limited thereto. Any equivalents or changes made by those who are familiar with the skill of the present invention in accordance with the spirit of the present invention shall be covered in the following patent application gardens. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic structural view of a field emission device according to a first embodiment of the present invention. FIG. 2 is a plan view of the field emission device of FIG. 1 taken along line 11-11. Figure 3 is a bottom plan view of the field emission device of Figure 1 taken along line I 11 -111. FIG. 4 is a flow chart of a method for lending a field emission device according to a first embodiment of the present invention. 099116607 Form No. A0101 Page 22/36 Page 0992029539-0 201142895 ^) 69] ® 5 is a schematic structural view of a field emission device according to a second embodiment of the present invention. [〇〇7〇] FIG. 6 is the third embodiment of the present invention. FIG. 7 is a schematic structural diagram of a field emission device according to a fourth embodiment of the present invention. [0072] FIG. 8 is a schematic diagram of a field emission device according to a fifth embodiment of the present invention. Schematic diagram of structure [0073] [Explanation of main component symbols] Field emission device: 100, 200, 300, 400, 50 Ό [0074] Insulation substrate: 110, 210, 310, 410, 510 [0075] First insulating isolation layer: 112, 212, 312, 412, 512 [0076] second opening: 1120 [0077] cathode electrode: 114, 214, 314, 414, 514 [0078] first opening: 1140, 2140, 4140 [0079] electron emission layer: 116 , 216, 316, 416, 516 [0080] electron emitter: 1162, 2162 [0081] electron emission end: 1164, 2164 [0082] electron extraction electrode: 118, 218, 318, 418, 518 [0083] secondary electron Emissive layer: 12〇, 220, 320, 420, 520 [0084] Second Insulation barrier: 121, 221, 321, 421, 521 099116607 Form No. A0101 Page 23 of 36 0992029539-0 201142895 [0085] Third opening: 1212, 3212 [0086] Gate electrode: 122, 222, 322 , 422, 522 [0087] second protrusion: 2142 [0088] first protrusion: 2202 [0089] secondary electron dynode: 424 [0090] fourth opening: 4240 [0091] secondary electron emission material: 4242 [0092] Third insulating isolation layer: 426 [0093] Anode electrode: 530 0992029539-0 099116607 Form number A0101 Page 24 of 36

Claims (1)

201142895 VII. Patent application scope: 1. A field emission device comprising: an insulating substrate; an electron extraction electrode disposed on a surface of the insulating substrate; a secondary electron emission layer, the secondary electron An emission layer is disposed on a surface of the electron extraction electrode; a cathode electrode is disposed at a distance from the electron eight extraction electrode through a first insulation isolation layer, and the electron extraction electrode is disposed between the cathode electrode and the germanium insulation substrate, The cathode electrode has a surface at least partially facing the electron extraction electrode, the cathode electrode has a first opening, the first opening defines an electron emission portion, and an electron emission layer disposed on the cathode electrode surface At least a portion of the surface of the electron extraction electrode; a gate electrode, the gate electrode is insulated from the cathode electrode, and the cathode electrode is disposed between the electron extraction electrode and the gate electrode. The field emission device of claim 1, wherein the cathode electrode has a through hole as the electron emission portion. 3. The field emission device of claim 1, wherein the cathode electrode comprises a plurality of strip-shaped conductors spaced apart by a distance and disposed in the same plane, and an interval between the plurality of strip-shaped conductors As the electron emission portion. 4. The field emission device of claim 1, wherein the electron emission layer is disposed at a position of a surface of the cathode electrode near the electron emission portion. 5. The field emission device of claim 1, wherein the electric 099116607 form number A0101 page 25/36 pages 0992029539-0 201142895 the sub-emissive layer at least partially with the secondary electron emission layer For the settings. 6. The field emission device of claim 1, wherein the first insulating spacer has a second opening corresponding to a first opening of the cathode electrode, and the first opening of the cathode electrode The second opening portion of the first insulating isolation layer is disposed to overlap, and the overlapping portion is defined as an electron emitting portion. 7. The field emission device of claim 1, wherein the electron emission layer comprises a plurality of electron emitters, and the electron emitters are carbon nanotubes, nano carbon fibers, and nanowires. One or more. 8. The field emission device of claim 7, wherein the electron emitter has an electron emission end, and the electron emission end is directed to the secondary electron emission layer. The field emission device of claim 8, wherein the surface of the secondary electron emission layer opposite to the electron emission portion has at least one first protrusion, the cathode electrode and the secondary electron emission layer The opposite surface has at least one second protrusion, the electron emission layer is disposed on a surface of the at least one second protrusion, and an electron emission end of the electron emitter is directed to a surface of the at least one first protrusion. 10. The field emission device of claim 8, wherein a maximum distance between the electron emission end and a surface of the secondary electron emission layer with respect to the electron emission end is smaller than an average free path of electrons and gas molecules. The field emission device of claim 10, wherein a maximum distance between the electron-emitting end and the surface of the secondary electron-emitting layer with respect to the electron-emitting end is 10 μm to 30 μm. 12. The field emission device of claim 1, wherein the gate electrode is disposed on a side of the cathode electrode remote from the electron extraction electrode, and is insulated from the cathode electrode by a second insulating spacer. Settings. The field emission device of the invention of claim 12, wherein the gate electrode is a metal grid and the gate electrode is covered by the method of the invention. The electron emission portion is disposed, and the metal grid is coated with a secondary electron emission material. The field emission device of claim 12, wherein the second insulating spacer has a third opening corresponding to the first opening of the cathode electrode, and the inner wall of the third opening is disposed The field emission device of the invention of claim 14, wherein the first insulating isolation layer has a second opening, and the second insulating isolation layer has a third opening, The first opening, the second opening, and the third opening are overlapped with each other. The overlapping portion is defined as an electron emitting portion. The field emission device of claim 12, wherein The thickness of the second insulating isolation layer is greater than 5 μm, and the size of the third opening gradually decreases in a direction away from the electron extraction electrode. 17 . The invention relates to the field emission device of claim 12, wherein the step further comprises a secondary electron doubled pole, the secondary electron dynode being disposed at the thumb electrode and the second insulation Between the layers, the secondary electron dynode and the gate electrode are separated by a third insulating spacer, and the secondary electron dynode has a fourth opening and a first opening of the cathode electrode. Corresponding to the ex, the inner wall of the fourth opening is provided with a secondary electron emission dip. The field emission device of claim 1, further comprising an anode electrode disposed at an interval from the gate electrode, wherein the gate electrode is disposed between the cathode electrode (10). For example, if the application is full (4), the electric potential of the electrode is higher than the potential of the cathode electrode and the potential of the electrode is between the potential of the electron extraction electrode, and the potential of the anode electrode is higher than the grid core. The electrode form is compiled with the potential of 0101 page 27 / total mega page 0992029539-0 201142895. 20. A field emission device, comprising: an insulating substrate; an electron extraction electrode disposed on a surface of the insulating substrate; a secondary electron emission layer, the secondary electron emission layer being disposed on the electron a surface of the extraction electrode; a cathode electrode disposed at a distance from the electron extraction electrode through a first insulating isolation layer disposed between the cathode electrode and the insulating substrate, the cathode electrode having a surface at least partially Facing the electron extraction electrode, the cathode electrode has a first opening, the first opening defines an electron emission portion, and an electron emission layer disposed at a portion of the cathode electrode facing the electron extraction electrode Surface; an anode electrode, the anode electrode is spaced apart from the cathode electrode, and the cathode electrode is disposed between the electron extraction electrode and the anode electrode. 099116607 Form No. A0101 Page 28 of 36 0992029539-0