JP2007234546A - Field emission type electron source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate assembling by enhancing support strength of a target base board, as to a field emission type electron source device in which image distortion caused by distortion of a front panel is not generated. <P>SOLUTION: The target base board 103 is housed in a vacuum vessel. An electron emitted from a field emission type electron source array 100 reaches an target 120 on the target base board. The target base board is supported by a spacer 105. A spring supporting and fixing member 102 disposed between the inner wall surface facing the target base board in the vacuum vessel and the target base board applies energizing force in the direction of pressing the target base board against the spacer to the target base board. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a field emission electron source device using a field emission electron source.

  In recent years, with the progress of semiconductor microfabrication technology, vacuum microelectronic technology that integrates a large number of micron-order cold cathode structures on a substrate such as a semiconductor attracts attention. Field emission electron source array with a micro cold cathode structure obtained by these technologies can be expected to have planar electron emission characteristics and high current density, and does not require a heat source such as a heater unlike a hot cathode. Therefore, expectation is gathered as an electron source for a next-generation flat display, a sensor, and a flat-type imaging device of a low power consumption type.

  As a vacuum device using such a field emission type electron source array, a field emission type electron source display device shown in Patent Literature 1 and Patent Literature 2, a field emission type electron source imaging device shown in Patent Literature 3, etc. It has been known.

  In general, a field emission electron source device using such a field emission electron source array has a front panel 1, a back panel 5, and a side peripheral device 4 made of frit glass, indium or the like as shown in FIG. It is equipped with a vacuum device that is fixed and fixed by a sealing material 9 and whose inside is kept in a vacuum.

  On the inner surface of the front panel 1, for example, an anode electrode 2 that transmits incident light from the outside is formed, and a target 3 is formed on the surface thereof. In general, the target 3 is a phosphor that is colored in three colors when used as a field emission type electron source display device, and when used as a field emission type electron source imaging device, incident light is converted into signal charges. It is a photoelectric conversion film that converts to.

  On the inner surface of the back panel 5, a plurality of cold cathode elements (emitters) 7, an insulating layer formed around each cold cathode element 7, a gate electrode for applying a voltage for extracting electrons from the cold cathode elements 7, etc. A semiconductor substrate 6 is provided on which a field emission electron source array in which peripheral elements 8 are integrated and integrated is formed. By landing the electron beam emitted from the cold cathode element 7 on the target 3, the field emission electron source display device emits a phosphor to display an image, and the field emission electron source imaging device has an image on the photoelectric conversion film. An image formed as incident light can be read.

  As a field emission electron source, generally, a cold cathode device having a sharp tip is formed on a semiconductor substrate, an insulating layer is formed around the cold cathode device, and a gate electrode is formed on the insulating layer. A typical example is a Spindt type in which voltage is applied between the gate electrode and electrons are emitted from the tip of the cold cathode device. In addition, an MIM (Metal Insulator Metal) type in which an insulating layer is formed between the cathode electrode and the gate electrode, and voltage is applied to the insulating layer to emit electrons by the tunnel effect, between the cathode electrode and the emitter electrode. An SCE (Surface Conduction Emitter) type that emits electrons from the micro gap by applying a voltage between these electrodes, or a carbon system such as DLC (Diamond Like Carbon) or CNT (Curbon Nanotube) as the emitter source A field emission electron source using a material can be given as an example.

  In a field emission electron source including such a cold cathode, the amount of electron emission from each cold cathode element is very small, so that it can be used as a field emission electron source display device, or field emission electron source imaging. When used as an apparatus, a cell (electron source cell) having a plurality of field emission electron sources as a unit (electron source cell) is formed to secure an amount of current necessary for performing a predetermined operation.

  The cells are arranged on a plane, for example, in a matrix. Specifically, a plurality of emitter lines extending in the vertical direction are arranged at equal pitches in the horizontal direction, and a plurality of gate lines extending in the horizontal direction are arranged at equal pitches in the vertical direction. A cell is arranged at each position where the gate line intersects. When the field emission electron source device is driven, an emitter line and a gate line are sequentially selected, whereby an electron beam is sequentially emitted from a cell at a position where the selected emitter line and gate line intersect. In this specification, a cell that emits an electron beam in this manner is hereinafter referred to as a “designated cell”. As described above, the field emission electron source display device can display an image, and the field emission electron source imaging device can read the image formed.

  In the field emission electron source, electrons are emitted by a strong electric field formed between the cold cathode element and the gate electrode, so that each cold cathode element has a predetermined spread of electrons (this spread angle is referred to as a “divergence angle”). For example, about 30 degrees).

  In the vacuum apparatus using such a field emission electron source, as shown in FIG. 14, the field emission electron source array is installed on the back panel 5 of the vacuum apparatus, and the electrons from the field emission electron source array are arranged. In general, a target 3 that performs a predetermined operation by landing a beam is formed on the front panel 1. Here, the distance from the field emission electron source array to the target 3 is uniquely determined by the distance from the back panel 5 on which they are provided to the front panel 1.

  That is, in such a conventional field emission type electron source device, the distance from the field emission type electron source array installed on the back panel 5 to the target 3 formed on the front panel 1 is as follows. Depending on the accuracy of the joint portion between the back panel 5 and the side peripheral device 4, it varies greatly with respect to the ideal design distance.

  For example, when the front panel 1 and the back panel 5 are joined to the side surface peripheral device 4 with frit glass interposed, variation in the amount of frit glass supplied or frit glass is baked and welded at about 400 ° C. Shrink or the like generated in the process causes variation in the distance from the field emission electron source array installed on the back panel 5 to the target 3 formed on the front panel 1.

  In addition, when the front panel 1 and the rear panel 5 are joined to the side peripheral device 4 by low temperature sealing with a soft metal such as indium interposed, indium is bonded to the front panel 1 at the time of sealing. A field emission electron source array in which variations in indium supply amount and crushing amount are installed on the back panel 5 in order to crush between the side periphery 4 and between the side periphery 4 and the back panel 5. To the target 3 formed on the front panel 1.

  The variation in the distance from the field emission electron source array to the target 3 as described above is about several hundred microns to several millimeters.

  Thus, in the conventional field emission electron source device, the distance between the field emission electron source array installed on the back panel 5 and the target 3 formed on the front panel 1 is managed with high accuracy. It is difficult to do. Then, electrons are emitted from each cold cathode element at a certain divergence angle. Therefore, the variation in the distance between the field emission type electron source array and the target 3 causes the variation in the extent of the electron beam spot formed by the electron beam on the target 3 (that is, the spot diameter). That is, as the distance between the field emission electron source array and the target 3 increases, the spot diameter of the electron beam on the target 3 increases, and as the distance decreases, the spot diameter of the electron beam on the target 3 decreases. To do. This is a very inconvenient problem for a field emission type electron source display device and a field emission type electron source imaging device that require a uniform image.

  In order to realize a high-definition field emission electron source display device and a high-definition field emission electron source imaging device, it is necessary to sufficiently reduce the size of the cells on the field emission electron source array. In this case, the distance between the field emission electron source array and the target 3 must be sufficiently small, and the error must be managed to be, for example, about several tens of microns or less. However, in the conventional field emission type electron source device, there is a possibility that the distance between the field emission type electron source array and the target 3 may vary from several hundred microns to several millimeters. It is difficult to realize an electron source display device and a high-definition field emission electron source imaging device.

  Further, in the conventional field emission type electron source device, when the inside of the vacuum vessel is evacuated, the front panel 1 is pressurized by the external pressure and curved in a concave shape. Since the target 3 is formed on the inner surface of the front panel 1, the distance between the field emission electron source array and the target 3 differs between the central portion and the peripheral portion of the target 3 due to the curvature of the front panel 1. become. That is, the distance between the field emission electron source array and the target 3 is short at the center of the target 3 and long at the periphery. Thereby, the diameter of the electron beam spot formed on the target 3 is different between the central portion and the peripheral portion of the target 3.

  As a result, when used as a field emission electron source display device, there is a difference in image quality displayed between the center of the screen and the periphery of the screen, and when used as a field emission electron source imaging device, the screen center and the screen are displayed. There is a difference in image quality between the surroundings.

  A field emission electron source device that solves the above problems is disclosed in Patent Document 4. This will be described with reference to FIGS. 15A and 15B. This field emission type electron source device includes a vacuum vessel in which a front panel 32, a back panel unit 10, and a side surface peripheral unit 31 are joined by a frit glass 34. A target 25 comprising a positive electrode 21, a photoconductive film 22, and an electron beam landing layer 23 is formed on the surface of the translucent substrate 20 provided between the front panel 32 and the back panel 10 on the back panel 10 side. ing. The back panel 10 is held on the back panel 10 via a spacer 30. On the inner surface of the rear panel 10, an emitter electrode 12, a cold cathode element 11 formed on the emitter electrode 12, an insulating layer 13 formed around the cold cathode element 11, and a gate electrode 14 formed on the insulating layer 13. A field emission electron source array 15 is provided.

  According to the field emission electron source device of FIGS. 15A and 15B, the field emission electron source array and the target are brought closer to each other as compared with the field emission electron source device of FIG. The distance between the two can be managed with high accuracy. This will be described below.

  In the field emission electron source device of FIG. 14, the target 3 is formed on the inner surface of the front panel 1. Therefore, the distance between the field emission type electron source array and the target 3 is the dimensional accuracy of the side peripheral device 4 between the front panel 1 and the back panel 5, the front panel 1 and the back panel 5 and the side peripheral device 4. Depends on the sealing material used for joining. When frit glass is used as the sealing material, variations in the supply amount of the frit glass and shrinkage generated in the process of firing and fusing the frit glass cause variations in the distance. In addition, when indium is used as the sealing material, variations in the supply amount and crushing amount of indium cause variations in the distance. Therefore, in the field emission electron source device of FIG. 14, it is difficult to bring the field emission electron source array and the target 3 close to each other and manage the distance between them with high accuracy.

  On the other hand, in the field emission electron source device of FIGS. 15A and 15B, the target 25 is formed not on the front panel 32 but on the translucent substrate 20. Therefore, the distance between the field emission electron source array 15 and the target 25 depends on the spacer 30. The bonding between the spacer 30 and the light-transmitting substrate 20 and the bonding between the spacer 30 and the back panel 10 need to be strong bonding for maintaining a vacuum in the vacuum vessel as in the sealing portion 10 in FIG. Therefore, it is possible to employ a bonding method that can manage the distance between the back panel 10 and the translucent substrate 20 with high accuracy. For example, instead of interposing the frit glass between the translucent substrate 20 and the back panel 10 and the spacer 30, it may be applied around the spacer 30 and fired at a high temperature. Or you may adhere | attach the translucent board | substrate 20, the back panel 10, and the spacer 30 so that distance dispersion | variation may not occur using a very small amount of adhesive etc. which do not affect the degree of vacuum.

  Therefore, in the field emission electron source device of FIGS. 15A and 15B, the field emission electron source array 15 and the target 25 are brought close to each other and the distance between them is managed with high accuracy. Can do. Thereby, the spot diameter of the electron beam on the target 25 can be reduced. As a result, a field emission type electron source display device capable of displaying a high definition image and a field emission type electron source imaging device capable of capturing a high definition image can be realized.

15A and 15B, the target 25 is formed not on the front panel 32 but on the translucent substrate 20. Therefore, the distance between the field emission electron source array 15 and the target 25 does not change even if the front panel 32 is pressurized and curved by the external pressure by evacuating the inside of the vacuum vessel. Thereby, an electron beam spot having a uniform diameter can be formed in the entire region on the target 25. As a result, a field emission type electron source display device capable of displaying an image with uniform image quality over the entire screen and a field emission type electron source imaging device capable of capturing images with uniform image quality over the entire screen can be realized.
JP-A-9-69347 JP-A-6-111735 JP 2000-48743 A JP-A-8-106869

  However, the field emission electron source device of FIGS. 15A and 15B has the following problems in practice.

  The first problem is due to the fact that the front panel 32 is curved in a concave shape due to the external atmospheric pressure by evacuating the vacuum vessel.

  For example, when used as a field emission type electron source display device, the front panel 32 in which the phosphor formed on the target 25 receives the electron beam from the field emission type electron source array 15 and the emitted light is curved in a concave shape. Since the image is refracted as it passes through, the image appears to be distorted.

  Further, when used as a field emission electron source imaging device, light from the subject is refracted when passing through the concavely curved front panel 32, so that the subject image formed on the target 25 is refracted. There is a problem that the image is distorted and a distorted image is captured.

  The second problem is caused by the fact that the translucent substrate 20 on which the target 25 is formed is supported only by the four spacers 30 provided at the four corners.

  By supporting the translucent substrate 20 with the four spacers 30, the space between the field emission electron source array 15 and the target 25 can be connected to the other space in the vacuum vessel. Therefore, if the inside of the vacuum vessel is evacuated, the space between the field emission electron source array 15 and the target 25 can also be evacuated. Therefore, the support structure of the translucent substrate 20 by the four spacers 30 is a reasonable structure in order to make the space between the field emission electron source array 15 and the target 25 a vacuum.

  However, such a support structure is insufficient from the viewpoint of mechanical strength in consideration of the weight of the structure including the target 25 and the translucent substrate 20.

  The translucent substrate 20 is formed with a target 25 including a positive electrode 21, a photoconductive film 22, and an electron beam landing layer 23 before being incorporated into a field emission electron source device. Therefore, the translucent substrate 20 needs to satisfy the ease of handling, thermal strength, physical strength, and the like required in these forming steps. Furthermore, it is necessary to have translucency and no outgassing in a vacuum. In consideration of these, generally, a glass plate having a thickness of, for example, about 1 to 3 mm is used as the translucent substrate 20. Since such a glass plate has a certain amount of weight, the supporting strength is insufficient with only the four minimal spacers 30 provided at the four corners.

  For example, in the case of being used as a field emission type electron source display device incorporated in a stationary TV apparatus, the translucent substrate 20 is installed so as to be substantially parallel to the vertical direction. There is a possibility that the translucent substrate 20 may be detached from the spacer 30 due to its own weight.

  Further, when used as a field emission type electron source display device by being incorporated in a mobile image display device, a large acceleration is applied by an impact or the like due to an inertial force generated in the target 25 and the translucent substrate 20. There is a possibility that a problem that the translucent substrate 20 is detached from the spacer 30 may occur.

  Alternatively, when used in a mobile camera having mobility as a field emission electron source imaging device, as in the case of the mobile image display device described above, a large acceleration is applied by an impact or the like. Thus, there is a possibility that the light transmitting substrate 20 is detached from the spacer 30 due to the inertial force generated in the target 25 and the light transmitting substrate 20.

  The third problem occurs when the distance between the field emission electron source array 15 and the target 25 is extremely small. In this case, it is necessary to use an extremely thin spacer 30, and when assembling the field emission electron source device, the handleability of the spacer 30 in operations such as positioning and adhesion of the spacer 30 is remarkably lowered, and the assembly becomes difficult. Problem arises.

  An object of the present invention is to solve the problems of the above-described conventional field emission electron source device.

  That is, an object of the present invention is to provide a field emission electron source device that does not cause image distortion due to distortion of the front panel.

  Another object of the present invention is to provide a field emission type electron source device in which the support strength of the substrate on which the target is formed is improved.

  Another object of the present invention is to provide a field emission electron source device that can be easily assembled.

  A field emission electron source device according to the present invention includes a field emission electron source array having a plurality of field emission cathodes, and the field emission electron source array facing the field emission electron source array and emitting from the field emission electron source array. A target substrate having a target to which a plurality of electron beams reach, and a vacuum container for accommodating the target substrate therein and holding a space between the field emission electron source array and the target in a vacuum. .

  In the first field emission electron source device of the present invention, the target is separated from the field emission electron source array, and a spacer for supporting the target substrate and the target substrate of the vacuum container are opposed to each other. And a spring support fixing member that is disposed between an inner wall surface and the target substrate and applies a biasing force in a direction of pressing the target substrate against the spacer to the target substrate.

  The second field emission electron source device of the present invention further includes a spacer for supporting the target substrate by separating the target from the field emission electron source array. The spacer includes a spacer portion that regulates a distance between the field emission electron source array and the target substrate, and the target substrate in a direction parallel to a surface of the target substrate that faces the field emission electron source array. And a frame portion that regulates the position of the frame.

  According to the first field emission type electron source device of the present invention, image distortion due to distortion of the front panel does not occur, and the support strength of the target substrate is improved.

  According to the second field emission type electron source device of the present invention, the support strength of the target substrate is improved and the handling property of the spacer is improved, so that the assembly is easy. Further, since the distance between the field emission electron source array and the target can be reduced, a high-definition field emission electron source device can be realized.

  The second field emission electron source device according to the present invention is disposed between an inner wall surface of the vacuum vessel facing the target substrate and the target substrate, and is attached in a direction to press the target substrate against the spacer. It is preferable to further include a spring support fixing member that applies a force to the target substrate.

  Thereby, in addition to the effect by the 2nd field emission electron source apparatus of this invention, the field emission electron source apparatus which has the effect by the said 1st field emission electron source apparatus of this invention is realizable.

  Furthermore, according to this preferable field emission type electron source device, it is not necessary to fix the target substrate and the spacer using an adhesive. As a result, the cost of the field emission electron source device can be reduced. Moreover, it can prevent that the emission characteristic of a field emission type electron source array falls by an adhesive agent. Furthermore, since the occurrence of the problem that the distance between the field emission electron source array and the target varies due to the variation in the amount of adhesive applied, the distance between the field emission electron source array and the target is It can be reduced to the limit that can ensure electrical insulation. As a result, a high-definition field emission electron source device can be realized.

  In the second field emission electron source device of the present invention, it is preferable that the target substrate is fixed to the spacer by fitting into the frame portion of the spacer. In this case, the first space surrounded by the field emission electron source array, the target substrate, and the spacer portion has a notch or hole for communicating with the space outside the first space in the vacuum vessel. It is preferably formed on the target substrate.

  As a result, the degree of vacuum in the first space can be increased and maintained, so that the lifetime of the field emission electron source device can be extended and the operation can be stabilized, and a high performance field emission electron source device can be obtained. be able to.

  In the second field emission electron source device of the present invention, the field emission electron source array includes a substrate and a plurality of cells electrically independent from each other and arranged in a matrix on the substrate. It is preferable to provide. Each of the plurality of cells comprises a plurality of field emission electron sources, and each of the plurality of field emission electron sources is formed on the substrate, the field emission cathode formed on the substrate, and An insulating layer having an opening formed at a position of the field emission cathode; and an extraction electrode formed on the insulating layer. It is preferable that an electrode structure in which a plurality of holes are formed so as to correspond to the plurality of cells on a one-to-one basis and to surround the plurality of cells is integrated with the spacer.

  As a result, an electron beam emitted with a predetermined spread (divergence angle) from the cells of the field emission electron source array is appropriately focused by the electrode structure, thereby providing a high-definition field emission electron source device. realizable.

  In addition, since the electrode structure is integrated with the spacer, the handleability of the thin and grid-like electrode structure having a large number of fine holes is improved, so that the assembly accuracy is improved. Therefore, a field emission electron source display device capable of displaying a high-definition and uniform image in the entire display region, and a field emission electron source capable of capturing a high-definition and uniform image in the entire imaging region An imaging device can be realized.

  In the first field emission electron source device of the present invention described above, it is preferable that the target and the outside of the vacuum vessel are electrically connected via the spring-like support fixing member.

  As a result, the spring support fixing member can be provided with a function of fixing the target substrate and a function of supplying power to the target, and an inexpensive field emission electron source device can be realized by reducing the number of parts and assembly man-hours. .

  Hereinafter, the present invention will be described in detail with reference to embodiments.

(Embodiment 1)
FIG. 1 is a cross-sectional view of a field emission electron source device according to Embodiment 1 of the present invention, and FIG. 2 is an enlarged cross-sectional view of a main part of the field emission electron source device according to Embodiment 1 of the present invention. FIG. 3 is an exploded perspective view of the field emission electron source device according to Embodiment 1 of the present invention.

  The field emission electron source device according to the first exemplary embodiment is a vacuum composed of a front panel 101 made of a light transmissive glass member, a back panel 107, and an annular side peripheral device 104 disposed therebetween. A container is provided. Reference numerals 108 and 109 denote sealing portions for sealing them.

  A semiconductor substrate 106 on which the field emission electron source array 100 is formed is provided on the surface of the back panel 107 facing the front panel 101. A rectangular target substrate 103 is provided in parallel to and spaced from the semiconductor substrate 106. A target 120 is formed on the surface of the target substrate 103 facing the field emission electron source array 100. The target substrate 103 is supported on the semiconductor substrate 106 via four columnar spacers 105. One end face of the four spacers 105 is bonded and fixed on the semiconductor substrate 106 in the vicinity of the four corners of the rectangular field emission electron source array 100, and the other end face is bonded and fixed to the four corners of the target substrate 103. .

  For convenience of the following description, as shown in the figure, the normal direction axis of the front panel 101 and the back panel 107 is referred to as a Z axis. The positive direction of the Z axis coincides with the traveling direction of the electron beam from the field emission electron source array 100 toward the target 120.

  A spring support fixing member 102 is attached to the surface of the target 120 facing the front panel 101. As shown in FIG. 4, the spring support fixing member 102 includes a rectangular frame-shaped fixed frame portion 102 b fitted and fixed to the target substrate 103, and cantilevered support structures attached to the four corners of the fixed frame portion 102 b. Spring part 102a. Each spring part 102a is elastically deformed when its free end abuts against the surface of the front panel 101 facing the target substrate 103. The spring support fixing member 102 applies a biasing force generated by elastic deformation of the spring portion 102 a to the target substrate 103 so that the target substrate 103 is pressed against the spacer 105.

  As shown in FIG. 5, the target substrate 103 has a rectangular plate shape and is made of a material such as glass having light transmittance. A target 120 is formed on the surface of the target substrate 103 facing the field emission electron source array 100. An electrode portion 103 b for supplying a potential to the target 120 passes through the target substrate 103. Four spacers 105 for fixing and separating the target substrate 103 from the semiconductor substrate 106 are bonded and fixed to the four corners of the surface of the target substrate 103 facing the field emission electron source array 100. When the field emission electron source device is used as a field emission electron source display device, the target 120 is made of, for example, indium oxide provided on the target substrate 103 and applied with a predetermined potential via the electrode portion 103b. It comprises a light-transmitting conductive film 110 as a main component and a phosphor layer 111 that is provided on the conductive film 110 and emits light upon receiving an electron beam emitted from the field emission electron source array 100.

  As shown in FIG. 3, the front panel 101 has a substantially disk shape and is made of a material such as glass having light transmittance. The front panel 101 includes an electrode portion 101a penetrating the front panel 101 and a spring portion 101b attached to the end of the electrode portion 101a on the target substrate 103 side. The tip of the spring part 101 b is in contact with the electrode part 103 b provided on the target substrate 103. Accordingly, a predetermined potential can be applied to the conductive film 110 of the target 120 from outside the vacuum vessel via the electrode portion 101a, the spring portion 101b, and the electrode portion 103b.

  An example of a method for assembling the field emission electron source device of the present embodiment will be briefly described.

  First, the back panel 107 and the side surface peripheral device 104 are joined by baking at a high temperature of about 400 ° C. with the frit glass 109 interposed between the back panel 107 and the side surface peripheral device 104.

  Next, the semiconductor substrate 106 on which the field emission electron source array 100 is formed is die-bonded to a portion surrounded by the side surface peripheral device 104 on the back panel 107. The power supply wiring pattern formed on the back panel 107 and the power supply electrode formed on the semiconductor substrate 106 are connected by wire bonding to form an electric circuit.

  The thus obtained back panel structure including the back panel 107, the side surface peripheral device 104, and the semiconductor substrate 106 is baked at a temperature of about 120 ° C. to 350 ° C. in a vacuum apparatus, and gas is discharged.

  Next, in vacuum, as shown in FIG. 3, the target substrate 103 and the springy supporting and fixing member 102 are assembled to the rear panel structure, and the side peripheral device 104 and the front panel 101 are made of frit glass or indium. A field emission electron source device is completed by forming a vacuum container having a vacuum inside by bonding and sealing.

  As shown in FIG. 2, the field emission electron source array 100 formed on the semiconductor substrate 106 includes a cold cathode element (field emission cathode, emitter) 112 having a sharpened tip formed on the substrate. An opening is formed at the position of the cold cathode element 112, an insulating layer 114 provided around the cold cathode element 112, and a lead electrode provided on the insulating layer 114 and having an opening surrounding the cold cathode element 112 ( Gate electrode) 113 and the like.

  One field emission electron is composed of one cold cathode element 112, an insulating layer 114 in which an opening corresponding to the cold cathode element 112 is formed, and an extraction electrode 113 in which an opening corresponding to the cold cathode element 112 is formed. The source is configured.

  A plurality of field emission electron sources are arranged close to each other in a region having a vertical and horizontal dimension of about 20 μm, for example, to constitute one cell. In the field emission electron source array 100, such a plurality of cells are arranged in a matrix in the vertical and horizontal directions. For example, in the case of a VGA compatible device, cells are arranged in a matrix of 640 in the horizontal direction and 480 in the vertical direction. At this time, the cells are electrically independent from each other so that they can be driven individually.

  A plurality of cold cathode elements 112 in the same cell are applied with a pulsed emitter potential that drops from a reference potential of, for example, 30 V to a low level of 0 V, and the extraction electrode 113 rises from a reference potential of, for example, 30 V to a medium level of 50 V A pulsed gate potential is applied. Electrons are emitted from the tip of the cold cathode device 112 due to a potential difference formed between the cold cathode device 112 and the extraction electrode 113. The emitter potential applied to the cold cathode element 112 and the gate potential applied to the extraction electrode 113 are supplied from outside the vacuum vessel via a wiring pattern formed on the back panel 107.

  A high voltage of about 100 V to several hundreds V, for example, is applied to the conductive film 110 provided on the surface of the target substrate 103 on the field emission electron source array 100 side.

  A predetermined emitter voltage and gate voltage are applied to each cell of the field emission electron source array 100 based on the video signal, and according to the potential difference between the cold cathode element 112 and the extraction electrode 113 formed thereby. An electron beam is emitted. The electron beam is attracted to a high voltage applied to the conductive film 110 and reaches the target 120 to cause the phosphor 111 to emit light. In this way, an image is formed on the target substrate 103.

  A space through which an electron beam passes, sandwiched between a semiconductor substrate 106 on which a field emission electron source array 100 is formed and a target substrate 103 in a vacuum vessel comprising a front panel 101, a back panel 107, and a side peripheral device 104. A getter pump 115 is installed in a space other than the above. The getter pump 115 holds the inside of the vacuum vessel at a high vacuum by adsorbing and removing excess gas.

  According to the field emission electron source device according to the first embodiment of the present invention described above, the front surface of the conventional field emission electron source device shown in FIGS. 15A and 15B has been provided. It is possible to solve the problems of image distortion due to the concave curvature of the panel 32 and insufficient support strength of the translucent substrate 20 on which the target 25 is formed. This will be described below.

  In the present embodiment, the springy supporting and fixing member 102 disposed between the front panel 101 and the target substrate 103 applies an urging force in a direction in which they are separated from each other to the front panel 101 and the target substrate 103. .

  The spring-like support fixing member 102 applies a biasing force from the inside to the outside of the vacuum vessel to the front panel 101, thereby correcting the concave curvature of the front panel 101 generated by the atmospheric pressure.

  Further, when the urging support fixing member 102 applies an urging force in the direction in which the target substrate 103 is pressed against the spacer 105 to the target substrate 103, the support strength of the target substrate 103 is increased as compared with the case where the urging force is not applied. To do. Therefore, for example, when a field emission type electron source display device is incorporated in a mobile image display device or used as a field emission type electron source imaging device, the target substrate is subjected to a large acceleration. Even if a large inertial force is generated in 103, the problem that the target substrate 103 is detached from the spacer 105 and destroyed is less likely to occur.

  1 to 5 show the case where the spring support fixing member 102 is made of a metal material having elasticity. However, the material of the spring support fixing member 102 is not limited to this, and a metal material having deformability may be used. Alternatively, a material other than a metal having a similar function may be used. Further, the shape of the spring support fixing member 102 is not limited to the shape shown in FIGS.

  In the above-described embodiment, the planar view shape of the side surface outer peripheral device 104 and the front panel 101 is a substantially circular shape. However, the shape is not limited to this, and there is no problem even if it is a substantially rectangular shape, for example.

  Further, in the above-described embodiment, an example in which the field emission electron source device is used as a field emission electron source display device in which the target 120 includes a phosphor is shown. However, an electric field in which the target 120 includes a photoelectric conversion film is shown. It can also be used as an emission electron source imaging device.

  When used as a field emission electron source imaging device, a light transmissive electrode such as ITO is provided between the photoelectric conversion film and the target substrate 103, and an aluminum thin film or the like is provided between the light transmissive electrode and the electrode portion 103b. It is desirable to connect with a conductive member that does not transmit light. This is because, for example, if the light transmissive electrode and the electrode portion 103b are connected with a light transmissive material such as ITO, a video signal is also generated from that portion, and noise may occur in the captured image. .

  Further, the periphery of the imaging region where the light transmissive electrode such as ITO is formed is surrounded by a non-light transmissive conductive film, and the electron beam from the field emission electron source array 100 is emitted at a time other than when the video signal is generated. It is preferable to irradiate the non-light transmissive conductive film portion. As a result, a video signal can be generated only in the imaging region where the light transmissive electrode film is formed, and noise generation or image distortion due to a rise in the potential of the photoelectric conversion film in the surrounding region of the imaging region, etc. Problems can be prevented from occurring.

(Embodiment 2)
FIG. 6 is a sectional view of a field emission type electron source device according to Embodiment 2 of the present invention. FIG. 7 is an exploded perspective view of the field emission electron source device according to Embodiment 2 of the present invention.

  The field emission electron source device according to the second embodiment is a vacuum composed of a front panel 101 made of a light transmissive glass member, a back panel 107, and an annular side peripheral device 104 disposed therebetween. A container is provided.

  A semiconductor substrate 106 on which the field emission electron source array 100 is formed is provided on the surface of the back panel 107 facing the front panel 101. A rectangular target substrate 117 is provided in parallel to and spaced from the semiconductor substrate 106. A target 120 is formed on the surface of the target substrate 117 facing the field emission electron source array 100. The target substrate 117 is supported on the semiconductor substrate 106 via the spacer 116.

  The second embodiment is different from the first embodiment in that the springy supporting and fixing member 102 of the first embodiment is not provided and in the configuration of the target substrate 117 and the spacer 116. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. The second embodiment will be described below with a focus on differences from the first embodiment.

  The field emission electron source device according to the second embodiment is a transparent device on which a target 25 is formed, which the conventional field emission electron source device shown in FIGS. 15A and 15B has. The problems that the supporting strength of the optical substrate 20 is insufficient and the handling of the extremely thin spacer 30 when assembling the field emission electron source device are extremely difficult can be solved. This will be described below.

  As shown in FIG. 8, the spacer 116 of the present embodiment has a rectangular frame shape as a whole, and a spacer that regulates and maintains the distance between the field emission electron source array 100 and the target substrate 117 with high accuracy. Part 116a and a frame part 116b for regulating the position of the target substrate 117 in a direction parallel to the surface of the target substrate 117 facing the field emission electron source array 100. The Z-axis direction dimension of the outer frame part 116b is larger than the Z-axis direction dimension of the spacer part 116a. The step between the spacer portion 116a and the frame portion 116b caused by the dimensional difference fits with the target substrate 117.

  In the present embodiment, when the distance between the field emission electron source array 100 and the target 120 is extremely small, only the dimension in the Z-axis direction of the spacer part 116a is changed without changing the dimension in the Z-axis direction of the frame part 116b. Should be reduced. Therefore, even if the thickness of the spacer portion 116a is reduced, the thickness and strength necessary for handling the spacer 116 can be ensured by the frame portion 116b. As a result, regardless of the distance between the field emission electron source array 100 and the target 120, the handling property of the spacer 116 alone is good in the assembly process of the field emission electron source device, and the field emission electron source device is assembled. Work becomes easy.

  Moreover, since the spacer part 116a is integrated with the frame part 116b, it is easy to reduce the thickness of the spacer part 116a. Therefore, the distance between the field emission electron source array 100 and the target 120 can be made smaller than that in the prior art. An electron beam is emitted from the field emission electron source array 100 with a predetermined spread (divergence angle). Therefore, the size of the spot formed by the electron beam on the target 120 increases as the distance between the field emission electron source array 100 and the target 120 increases. In the present embodiment, since the distance between the field emission electron source array 100 and the target 120 can be made smaller than before, the spot diameter of the electron beam on the target 120 can be made smaller. As a result, a high-definition image can be displayed in the field emission electron source display device in which the target 120 is provided with a phosphor, and high in a field emission electron source imaging device in which the target 120 is provided with a photoelectric conversion film. A fine image can be taken.

  Further, the target substrate 117 is held by the spacer 116 by fitting the outer peripheral end thereof to the step of the spacer 116. Therefore, the support strength of the target substrate 117 is improved.

  As shown in FIG. 9, the target substrate 117 has a rectangular plate shape and is made of a material such as glass having light transmissivity. A target 120 is formed on the surface of the target substrate 117 facing the field emission electron source array 100. An electrode portion 103 b for supplying a potential to the target 120 passes through the target substrate 117.

  A cutout 117c is formed at the outer peripheral end of the target substrate 117 to which the spacer 116 is fitted. The notch 117c is a first space 131 (see FIG. 6) surrounded by the semiconductor substrate 106, the target substrate 117, and the spacer 115 in a state where the target substrate 117 is fitted on the spacer 116 and installed on the semiconductor substrate 106. And a vent hole that communicates with the second space 132 outside the first space 131 in the vacuum vessel. As a result, even if an electron beam emitted from the field emission electron source array 100 collides with a wall surface forming the first space 131 and gas is generated, it is guided to the second space 132 through the notch 117c. It can be adsorbed by the getter pump 115. In the assembly of the field emission electron source device, when the target substrate 117 is installed on the semiconductor substrate 106 via the spacer 116, the front panel 101 is attached in a vacuum atmosphere and the vacuum vessel is sealed. The inside of the first space 131 can be evacuated and vacuumed through the notch 117c. That is, an electron beam is emitted from the field emission electron source array 100 toward the target 120 even when the spacer 116 having a rectangular frame shape is used so as to surround the outer periphery of the target substrate 117 as in the present embodiment. The degree of vacuum in the first space 131 can be increased and maintained. As a result, the lifetime of the field emission electron source device can be extended and the operation can be stabilized, and a high performance field emission electron source device can be obtained.

  In the above-described embodiment, an example in which the field emission type electron source device is used as a field emission type electron source display device in which the target 120 is provided with a phosphor is shown, but as described in the first embodiment, It can also be used as a field emission electron source imaging device having a photoelectric conversion film on the target 120.

(Embodiment 3)
FIG. 10 is a cross-sectional view of a field emission type electron source device according to Embodiment 3 of the present invention. FIG. 11 is an exploded perspective view of the field emission electron source device according to Embodiment 3 of the present invention. The third embodiment has a configuration in which the first embodiment and the second embodiment are combined.

  That is, the field emission electron source device according to the third exemplary embodiment is similar to the first exemplary embodiment on the surface of the target substrate 117 supported by the spacer 116 on the side facing the front panel 101 as in the second exemplary embodiment. Similarly, a spring support fixing member 102 is attached. The same members as those in the first and second embodiments are denoted by the same reference numerals, and description thereof will be omitted.

  As shown in FIG. 4, the spring support fixing member 102 includes a rectangular frame-shaped fixing frame portion 102 b that is fixed by being fitted to the target substrate 117, as shown in FIG. And a spring portion 102a having a cantilever support structure attached to the four corners of the portion 102b. The spring support fixing member 102 applies an urging force in a direction in which both are separated from each other to the front panel 101 and the target substrate 117.

  In the present embodiment, by providing the springy support fixing member 102 described in the first embodiment, the same effect as described in the first embodiment can be obtained. In addition, by providing the target substrate 117 and the spacer 116 described in the second embodiment, the same effect as described in the second embodiment can be obtained.

  Furthermore, the following effects can be obtained in the present embodiment.

  That is, the movement of the target substrate 117 is restricted by being pressed against the spacer 116 by the urging force of the springy supporting and fixing member 102 in the Z-axis direction, and the frame of the spacer 116 is perpendicular to the Z-axis direction. The movement is restricted by fitting with the part 116b. Therefore, it is not necessary to fix the target substrate 117 and the spacer 116 using an adhesive.

  As a result, the cost of the field emission electron source device can be reduced, and the emission characteristics of the field emission electron source array can be prevented from being lowered by the adhesive.

  Furthermore, since it is not necessary to apply an adhesive between the target substrate 117 and the spacer 116, the distance between the field emission electron source array 100 and the target 120 varies due to variations in the amount of adhesive. Generation | occurrence | production is eliminated and the distance precision between the field emission type electron source array 100 and the target 120 can be improved. As a result, the distance between the field emission electron source array 100 and the target 120 can be reduced to the limit where electrical insulation can be ensured. As a result, since the spot diameter of the electron beam on the target 120 can be further reduced, a higher-definition image can be displayed in the field emission electron source display device provided with the phosphor on the target 120, In the field emission type electron source imaging device in which the target 120 is provided with a photoelectric conversion film, a higher-definition image can be taken.

  Also in the third embodiment, as described in the first embodiment, the material of the springy supporting and fixing member 102 is not limited to a metal material having elasticity, and may be a metal material having deformability or the same. A material other than a metal having the above function may be used. Further, the shape of the springy supporting and fixing member 102 is not limited to the above shape.

  Further, in the above-described embodiment, an example in which the field emission electron source device is used as a field emission electron source display device in which the target 120 is provided with a phosphor is shown, but the same as described in the first embodiment. In addition, it can also be used as a field emission electron source imaging device having a photoelectric conversion film on the target 120.

  In Embodiments 2 and 3, the cutout 117c is formed by removing only a part of the outer peripheral end of the surface of the target substrate 117 facing the field emission electron source array 100. However, the semiconductor substrate 106 and the target substrate 9 is not limited to the notch 117c in FIG. 9 as long as the gas can move between the first space 131 surrounded by 117 and the spacer 115 and the second space 132 outside. For example, as shown in FIG. 12, a part of the outer peripheral edge of the target substrate 117 is removed so as to reach from the surface facing the field emission electron source array 100 to the surface facing the front panel 101. It may be a groove-shaped notch 117d. Alternatively, as shown in FIG. 13, a hole 117e penetrating the target substrate 117 in the Z-axis direction may be used.

  In the first and third embodiments, the conductive film 110 of the target 120 and the outside of the vacuum container may be electrically connected via the springy support fixing member 102. Thereby, for example, the spring portion 101b provided on the front panel 101 can be omitted. As described above, the springy supporting and fixing member 102 has both the function of fixing the target substrates 103 and 117 and the function of supplying power to the target 120, thereby reducing the number of parts and the number of assembling steps, thereby reducing the cost of the field emission electron source device. Can be realized.

  In the second and third embodiments, the relationship between the spacer portion 116a of the spacer 116 and the formation region of the target 120 on the target substrate 117 is not particularly limited, but the thickness of the target 120 is different from that of the field emission electron source array 100 and the target. When the distance to the distance 120 is so large that it cannot be ignored, it is preferable that the target 120 is not formed in the area where the spacer 116a around the target substrate 117 contacts. If the thick target 120 is interposed between the target substrate 117 and the spacer portion 116 a in a state where the target substrate 117 is fitted to the spacer 116, the field emission electron source array 100 and the target 120 are caused by the thickness variation of the target 120. This is because the distance accuracy between the two is reduced.

  In the second and third embodiments, the inner wall surface of the frame portion 116b of the spacer 116 to which the target substrate 117 is fitted has a larger inner dimension on the front panel 101 side in the Z-axis direction and smaller on the rear panel 107 side. It is preferable to be inclined. Thus, by making the inner wall surface of the frame portion 116b a tapered surface, the operation of fitting the target substrate 117 to the spacer 116 becomes easy.

  That is, when the target substrate 117 is fitted to the spacer 116, even if the target substrate 117 is slightly displaced from the spacer 116, the target substrate 117 with respect to the spacer 116 in the process of dropping due to its own weight. The deviation is corrected by the target substrate 117 being guided by the tapered surface of the frame portion 116b. Then, in a state where the target substrate 117 is landed on the upper surface of the spacer portion 116a, the displacement of the target substrate 117 with respect to the spacer 116 is automatically eliminated. Therefore, the assembling accuracy and assembling workability between the target substrate 117 and the spacer 116 are remarkably improved.

  In the first to third embodiments, a plurality of through holes are provided between the field emission electron source array 100 and the target 120 so as to correspond to each cell of the field emission electron source array 100 on a one-to-one basis and surround each cell. A grid-like focus electrode in which is formed may be provided. A voltage lower than the voltage applied to the target 120 is supplied to the focus electrode. The electron beam emitted from the cells of the field emission electron source array 100 with a predetermined spread (divergence angle) is appropriately focused by the electric field formed in the through hole of the focus electrode. Thereby, the divergence angle of the electron beam which radiate | emits a focus electrode becomes small compared with the case where a focus electrode is not provided. For this reason, the spot diameter of the electron beam on the target 120 can be reduced. As a result, a high-definition image can be displayed in the field emission electron source display device in which the target 120 is provided with a phosphor, and high in a field emission electron source imaging device in which the target 120 is provided with a photoelectric conversion film. A fine image can be taken.

  In the case of providing such a focus electrode in the second and third embodiments, it is preferable that the focus electrode be integrally formed at the end of the spacer 116 on the semiconductor substrate 106 side. The spacer integrated with the focus electrode can be formed by a semiconductor microfabrication technique using a semiconductor wafer containing silicon.

  By using a semiconductor microfabrication technology, for example, a focus electrode made of a fine lattice structure having an extremely thin thickness of about 0.01 mm to 0.04 mm and a through hole arrangement pitch of 0.02 mm can be easily formed. Can do. Further, since the focus electrode is integrated with a thick and strong spacer, the focus electrode can be easily handled. Therefore, when assembling the field emission electron source device, the alignment of the through hole of the focus electrode and the cell of the field emission electron source array 100 can be performed easily and with high accuracy. Further, as compared with the case where the focus electrode and the spacer 116 are separately formed, the assembling work of the focus electrode and the spacer 116 becomes unnecessary, and the relative positional relationship between the focus electrode and the frame portion 116b of the spacer 116 is changed. High accuracy can be achieved on the order of microns. Furthermore, the dimension in the Z-axis direction of the spacer portion 116a of the focus electrode and the spacer 116 can be improved to a micron order. As a result, the relative positional accuracy between the field emission electron source array 100 and the target 120 in the Z-axis direction and the direction orthogonal thereto is improved. As a result, in the field emission type electron source display device in which the target 120 is provided with a phosphor, a high-definition and uniform image can be displayed in the entire display region, and the field emission type in which the target 120 is provided with a photoelectric conversion film. The electron source imaging device can capture a high-definition and uniform image within the entire imaging region. In addition, since the relative positional accuracy between the focus electrode and the target 120 in the direction orthogonal to the Z-axis is improved, for example, in a color display device in which the target 120 includes phosphors of three colors, a high-definition color image is displayed. can do.

  In the first to third embodiments, it is preferable to provide a transparent electrode layer on the surface of the target substrates 103 and 117 facing the front panel 101. Thus, when the field emission electron source device is assembled, the target substrates 103 and 117 can be transported by holding the target substrates 103 and 117 using the electrostatic chuck. Therefore, the target substrates 103 and 117 can be easily transferred, and the field emission electron source device can be assembled easily and with high accuracy. Further, it is not necessary to form grooves or claws for holding on the target substrates 103 and 117. In addition, since the transparent electrode layer does not block the light emitted from the target 120 when the target 120 includes a phosphor, it does not impair the function of the field emission electron source display device. Since the light incident on the target 120 is not blocked when the conversion film is provided, the function of the field emission electron source imaging device is not impaired.

  The field of application of the present invention is not particularly limited, and can be used for, for example, a field emission electron source display device and a field emission electron source imaging device.

FIG. 1 is a cross-sectional view of a field emission electron source device according to Embodiment 1 of the present invention. FIG. 2 is an enlarged cross-sectional view of a main part of the field emission electron source device according to Embodiment 1 of the present invention. FIG. 3 is an exploded perspective view of the field emission electron source device according to Embodiment 1 of the present invention. FIG. 4 is a perspective view of a springy support fixing member used in the field emission electron source device according to the first exemplary embodiment of the present invention. FIG. 5 is a perspective view of a target substrate used in the field emission electron source device according to Embodiment 1 of the present invention. FIG. 6 is a cross-sectional view of a field emission electron source device according to Embodiment 2 of the present invention. FIG. 7 is an exploded perspective view of the field emission electron source device according to Embodiment 2 of the present invention. FIG. 8 is a perspective view of a spacer used in the field emission electron source device according to Embodiment 2 of the present invention. FIG. 9 is a perspective view of a target substrate used in the field emission electron source apparatus according to Embodiment 2 of the present invention. FIG. 10 is a cross-sectional view of a field emission type electron source device according to Embodiment 3 of the present invention. FIG. 11 is an exploded perspective view of the field emission electron source device according to Embodiment 3 of the present invention. FIG. 12 is a perspective view of another target substrate used in the field emission electron source device according to the second and third embodiments of the present invention. FIG. 13 is a perspective view of still another target substrate used in the field emission electron source device according to the second and third embodiments of the present invention. FIG. 14 is a cross-sectional view showing a schematic configuration of a conventional field emission electron source device. FIG. 15A is a plan view showing a schematic configuration of another conventional field emission electron source device, and FIG. 15B is a sectional view thereof.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Field emission type electron source array 101 Front panel 101a Electrode part 101b Spring part 102 Spring support support fixing member 102a Spring part 102b Fixing frame part 103 Target substrate 103b Electrode part 104 Side surface peripheral device 105 Spacer 106 Semiconductor substrate 107 Rear panel 108,109 Sealing portion 110 Conductive film 111 Phosphor layer 112 Cold cathode device (field emission type cathode, emitter)
113 Lead electrode (gate electrode)
114 Insulating layer 115 Getter pump 116 Spacer 116a Spacer 116b Frame 117 Target substrate 117c, 117d Notch 117e Hole 120 Target

Claims (6)

A field emission electron source array comprising a plurality of field emission cathodes;
A target substrate comprising a target facing the field emission electron source array and to which a plurality of electron beams emitted from the field emission electron source array reach;
A field emission electron source device comprising: a vacuum vessel that houses the target substrate therein and holds a space between the field emission electron source array and the target in a vacuum;
A spacer for separating the target from the field emission electron source array and supporting the target substrate;
A springy supporting and fixing member disposed between an inner wall surface of the vacuum container facing the target substrate and the target substrate, and applying a biasing force in a direction to press the target substrate against the spacer. A field emission electron source device comprising: A field emission electron source array comprising a plurality of field emission cathodes;
A target substrate comprising a target facing the field emission electron source array and to which a plurality of electron beams emitted from the field emission electron source array reach;
A field emission electron source device comprising: a vacuum vessel that houses the target substrate therein and holds a space between the field emission electron source array and the target in a vacuum;
A spacer for separating the target from the field emission electron source array and supporting the target substrate;
The spacer includes a spacer portion that regulates a distance between the field emission electron source array and the target substrate, and the target substrate in a direction parallel to a surface of the target substrate that faces the field emission electron source array. A field emission type electron source device.   A spring support fixing member that is disposed between an inner wall surface of the vacuum vessel facing the target substrate and the target substrate and applies a biasing force in a direction to press the target substrate against the spacer. The field emission electron source device according to claim 2. The target substrate is fixed to the spacer by fitting into the frame portion of the spacer,
A cutout or a hole is formed in the target substrate so that a first space surrounded by the field emission electron source array, the target substrate, and the spacer portion communicates with a space outside the first space in the vacuum vessel. The field emission electron source device according to claim 2, wherein the field emission electron source device is formed. The field emission electron source array includes a substrate and a plurality of cells electrically independent from each other and arranged in a matrix on the substrate,
Each of the plurality of cells comprises a plurality of field emission electron sources,
Each of the plurality of field emission electron sources includes the field emission cathode formed on the substrate, an insulating layer formed on the substrate and having an opening formed at the position of the field emission cathode, An extraction electrode formed on the insulating layer,
3. The field emission electron source according to claim 2, wherein an electrode structure in which a plurality of holes are formed so as to correspond to the plurality of cells on a one-to-one basis and to surround the plurality of cells is integrated with the spacer. apparatus. The field emission electron source device according to claim 1 or 3, wherein the target and the outside of the vacuum vessel are electrically connected via the springy support fixing member.

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