EP1615254A1 - Dispositif et procédé pour minimiser le flux de verre dans la fabrication d'une plaque à microcanaux - Google Patents
Dispositif et procédé pour minimiser le flux de verre dans la fabrication d'une plaque à microcanaux Download PDFInfo
- Publication number
- EP1615254A1 EP1615254A1 EP04400034A EP04400034A EP1615254A1 EP 1615254 A1 EP1615254 A1 EP 1615254A1 EP 04400034 A EP04400034 A EP 04400034A EP 04400034 A EP04400034 A EP 04400034A EP 1615254 A1 EP1615254 A1 EP 1615254A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- boule
- flat
- tube
- dimension
- glass
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J43/00—Secondary-emission tubes; Electron-multiplier tubes
- H01J43/04—Electron multipliers
- H01J43/06—Electrode arrangements
- H01J43/18—Electrode arrangements using essentially more than one dynode
- H01J43/24—Dynodes having potential gradient along their surfaces
- H01J43/246—Microchannel plates [MCP]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/02—Manufacture of electrodes or electrode systems
- H01J9/12—Manufacture of electrodes or electrode systems of photo-emissive cathodes; of secondary-emission electrodes
- H01J9/125—Manufacture of electrodes or electrode systems of photo-emissive cathodes; of secondary-emission electrodes of secondary emission electrodes
Definitions
- the present invention relates to inicrochannel plates for use with image intensifiers, and more specifically, to an arrangement for reducing glass flow during the manufacture of the plates.
- Microchannel plates are used as electron multipliers in image intensifiers. They are thin glass plates having an array of channels extending therethough and are located between a photocathode and a phosphor screen. An incoming electron from the photocathode enters the input side of the microchannel plate and strikes a channel wall. When voltage is applied across the microchannel plate these incoming or primary electrons are amplified, generating secondary electrons. The secondary electrons then exit the channel at the back end of the microchannel plate and are used to generate an image on the phosphor screen.
- fabricating a microchannel plate starts with a fiber draw processes.
- An etchable core rod is drawn within a non-etchable silicate tube to form a round fiber comprised of a core rod and cladding layer.
- These fibers are then bundled and drawn into an equilateral hexagonal shaped pre-form known as a multi-fiber bundle.
- Each multi-fiber bundle can contain over 10,000 core rod sites.
- These hex-shaped multi-fiber bundles are packed into a glass packing tube and non-etchable hexagonally shaped support rods are packed between the bundles and the cylindrical wall to form a boule that is fused together in a heating process to produce a solid boule of rim glass and fiber optics.
- Subsequent process steps entail slicing, beveling, and polishing the glass boule into plates. Afterwards, the plates are etched to remove the core rods within the plates to thus form the channels, each of which is defined by the cladding layer. The channels are then activated and metallized.
- Movement of the fibers closer together can lead to missing channel walls after the etch process because there will not be enough cladding glass to form a wall between the channels. These missing channel walls can lead to any number of defects such as ion barrier or film emission points, reduced structural integrity and ruptures.
- the present invention includes a hollow packing tube formed of generally non-etchable glass for use in fabricating a microchannel plate.
- the packing tube has a plurality of flat inner surfaces. Each surface is generally planar and extends generally parallel to the longitudinal axis of the tube.
- the invention in another aspect, includes a boule having a plurality of optical fibers, each of which has a core formed of etchable material and a cladding layer formed of a non-etchable material and a plurality of support rods formed of a non-etchable material.
- the fibers and rods are disposed in the glass packing tube with the rods located between the fibers and the flat inner surfaces of the packing tube.
- the invention includes a method of forming a microchannel plate.
- the method includes the steps of providing a bundle of fibers having an etchable core surrounded by a non-etchable cladding, packing the fibers into a glass packing tube having a plurality of flat inner surfaces, positioning a plurality of support rods between the fibers and the flat inner surfaces of the packing tube to form a packed boule and fusing the packed boule into a solid boule.
- the present invention relates to a glass packing tube 550 used to form boules and which tube is configured to reduce the amount of glass flow when fusing the boule during manufacture of microchannel plates.
- the packing tube 550 according to the present invention is made of non-etchable glass and has multiple flat interior surfaces 501 through 512. These flat surfaces are planar surfaces and allow the packing of fiber bundles 16 and support rods 24 within the glass packing tube 550 while maintaining minimal open space (as compared to a round internal surface) between the outermost support rods and the interior surface of the packing tube. This minimization of open space is advantageous because it reduces the flow of glass during the fusion process that forms a fused boule.
- FIG. 3 shows a starting fiber 10 used to manufacture a microchannel plate for use as an electron multiplier.
- the fiber 10 includes a glass core 12 and a glass cladding 14 surrounding the core.
- the core 12 is made of a material that is etchable in an appropriate etching solution such that the core can be subsequently removed.
- the glass cladding 14 is made from a glass which has softening temperature substantially the same as the glass core 2.
- the glass material of the cladding 14 is different from that of the core 12 in that it has a higher lead content which renders it non-etchable under the conditions used for etching the core material.
- the cladding 14 remains after the etching of the glass core 12 and becomes a boundary for the channel 32 which is left.
- the optical fibers 10 may be formed in the following manner.
- An etchable glass rod and a cladding tube coaxially surrounding the rod are suspended vertically in a draw machine which incorporates a zone furnace.
- the temperature of the furnace is elevated to the softening temperature of the glass.
- the rod and tube fuse together and are drawn into the single fiber 10.
- the fiber 10 is fed into a traction mechanism where the speed is adjusted until the desired fiber diameter is achieved.
- the fiber 10 is then cut into shorter lengths.
- the multi-fiber or bundle 16 includes several thousand single fibers 10 each having the core 12 and the cladding 14 discussed above. This bundle 16 is then suspended vertically in a draw machine and drawn to again decrease the fiber diameter while still maintaining the hexagonal configuration of the individual fibers. The bundle 16 may then cut into shorter lengths.
- the packing tube 550 is made of glass material which is similar to the glass cladding 14 and it too is non-etchable when etching away the glass core 12.
- the glass packing tube 550 has a coefficient of expansion which is approximately the same as that of the fibers 10.
- the lead glass packing tube 550 will eventually become the solid rim border of the microchannel plate as shown in Fig. 2.
- a plurality of support structures are positioned in the glass packing tube 550 between the bundles 16 and flat interior surfaces 501 through 512 of the tube.
- the support structures may take the form of hexagonal rods of any material which is not etchable under the etching conditions used later to etch the core 12 and which has the necessary strength and the capability to fuse with the glass fibers.
- Such support structures are shown as support rods 24.
- the support rods may be one optical fiber or preferably a bundle of any number of fibers up to several hundred.
- the final geometric configuration and outside dimensions of one support rod is substantially the same as one bundle 16.
- the assembly thus formed by the fibers 10, support rods 24 and packing tube 550 is a packed boule 500 as shown in Fig. 5.
- the boule 500 is then suspended in a furnace and is connected to a vacuum system.
- the temperature of the furnace is elevated to the softening point of the material of the bundles 16 and the support rods 24.
- the bundles 16 fuse together, and the support rods 24 fuse to its adjacent bundles 16 and to the inner surface of the packing tube 550.
- the support rods 24 act as a cushion between the interior surface of the glass packing tube 550 and the bundles 16. This cushioning provides structural support so that the individual fibers 10 do not distort during the heat treatment. In addition, the cushioning effect of the support fibers 24 makes it possible to use a higher heat during fusion without causing distortion of the fibers 10.
- the fused boule is then sliced into thin cross-sectional plates.
- the planar end surfaces are ground and polished.
- the cores 12 of the fibers 10 are removed by etching with dilute hydrochloric acid. After etching, the high lead content glass claddings 14 will remain and form the channels 32.
- the support rods 24 will also remain solid and thus provide a good transition from the solid rim of the glass packing tube 550 to the microchannels 32.
- the plates After etching, the plates are placed in an atmosphere of hydrogen gas whereby the lead oxide of the non-etched lead glass is reduced to render the cladding electron emissive.
- a semiconducting layer is formed in each of the glass claddings 14 and this layer extends inwardly from the surface which bounds each microcharmel 32.
- Thin metal layers are applied as electrical contacts to each of the planar end surfaces of the microchannel plate which provide entrance and exit paths for electrons when an electric field is established across the microchannel plate by means of the metallized contacts.
- FIG. 5 shows a cross-sectional view of the packed boule 500 having a packing tube 550 formed with a plurality of flat or planar, inner surfaces 501-512 (in the case of Fig. 5, the number of flat surfaces is twelve).
- planar it is meant that each surface forms a plane and each plane, i.e., each surface extends longitudinally and parallel to the central axis 600 of the tube 550 and is generally perpendicular to the radius of the outer wall of the tube.
- These inner surfaces can be provided by either machining or mandrel shrinking (over a shaped mandrel) the inside surface of the glass packing tube. Such techniques for forming such glass tubes are known to those skilled in the art.
- the number of sides can vary and is dependant on the size and shape of the fused boule. In the embodiment disclosed herein where the boule has a generally circular cross-section, it is preferred that the tube 550 has at least 8 flat surfaces and preferably, 12 such surfaces.
- the support rods 24 can be pushed into the tube 550 in either bearing contact with the inner surfaces or in very close proximity thereto.
- the rods 24 have a hexagonal cross-section
- a flat surface of at least some of the rods bears on some of the flat inner surfaces 501 through 512 of the packing tube 550 and a vertex of some of the other rods bears on the flat surfaces.
- the open spaces between the rods 24 and tube 550 are primarily in the vicinity of the vertices between the flat inner surfaces 501 through 512.
- the facets or surfaces of the multi-sided glass packing tube have different widths (the dimension transverse to the longitudinal axis of the tube 550).
- FIG. 5 shows this feature.
- the variation in the width of the flat surfaces depends on the size and shape of the boule to be formed. In the embodiment disclosed herein, 2 different widths are disclosed.
- the widths surfaces 501, 503, 505, 507, 509 and 511 are the same dimension and are smaller than the widths of surfaces 502, 504, 506, 508, 510 and 512 and all of this latter group are the same dimension. For other desired boule shapes, different variations could be used.
- a comparison between the open spaces 300 of the prior art boule shown in FIC.1 and open spaces seen in FIG. 5 shows a large reduction of open area. This reduction can easily exceed 50% when compared to the prior art boule.
- Such reduction of open space is important because it reduces the flow of glass during the fusion process. Any level of glass flow can cause the core rods within each bundle of fibers within the boule to move. This movement of the core rods, as discussed above, has the potential to reduce the cladding dimension between each core site. If the clad glass thickness between two sites is reduced too much then there is a potential during the etching step for the clad glass to disappear completely. The absence of any clad glass between two core sites causes a missing channel wall within the plate which damages the performance of the plate.
- the reduction in glass flow which is concomitant with the reduction in open space increases the uniformity of the cores within each hex-shaped fiber bundle within the boule. This increase in uniformity produces a superior plate as compared to prior art packing tubes formed with round interior walls.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Electron Tubes For Measurement (AREA)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP20040400034 EP1615254B1 (fr) | 2004-07-05 | 2004-07-05 | Dispositif et procédé pour minimiser le flux de verre dans la fabrication d'une plaque à microcanaux |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP20040400034 EP1615254B1 (fr) | 2004-07-05 | 2004-07-05 | Dispositif et procédé pour minimiser le flux de verre dans la fabrication d'une plaque à microcanaux |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1615254A1 true EP1615254A1 (fr) | 2006-01-11 |
EP1615254B1 EP1615254B1 (fr) | 2008-12-24 |
Family
ID=34932034
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP20040400034 Expired - Fee Related EP1615254B1 (fr) | 2004-07-05 | 2004-07-05 | Dispositif et procédé pour minimiser le flux de verre dans la fabrication d'une plaque à microcanaux |
Country Status (1)
Country | Link |
---|---|
EP (1) | EP1615254B1 (fr) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1470889A (en) * | 1973-07-05 | 1977-04-21 | Philips Electronic Associated | Fibre plate |
EP0225656A1 (fr) * | 1985-11-07 | 1987-06-16 | Koninklijke Philips Electronics N.V. | Dispositif de formation d'image comportant une plaque de fibres optiques |
US5378955A (en) * | 1971-11-08 | 1995-01-03 | Intevac, Inc. | Method for fabrication of a microchannel electron multiplier |
-
2004
- 2004-07-05 EP EP20040400034 patent/EP1615254B1/fr not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5378955A (en) * | 1971-11-08 | 1995-01-03 | Intevac, Inc. | Method for fabrication of a microchannel electron multiplier |
GB1470889A (en) * | 1973-07-05 | 1977-04-21 | Philips Electronic Associated | Fibre plate |
EP0225656A1 (fr) * | 1985-11-07 | 1987-06-16 | Koninklijke Philips Electronics N.V. | Dispositif de formation d'image comportant une plaque de fibres optiques |
Also Published As
Publication number | Publication date |
---|---|
EP1615254B1 (fr) | 2008-12-24 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4853020A (en) | Method of making a channel type electron multiplier | |
US4912314A (en) | Channel type electron multiplier with support rod structure | |
US3275428A (en) | Method of making honeycomb structure | |
US5795206A (en) | Fiber spacers in large area vacuum displays and method for manufacture of same | |
US3979621A (en) | Microchannel plates | |
US7221837B2 (en) | Device and method for reducing glass flow during the manufacture of microchannel plates | |
US8135253B2 (en) | Microchannel plate (MCP) having an asymmetric packing pattern for higher open area ratio (OAR) | |
US6155900A (en) | Fiber spacers in large area vacuum displays and method for manufacture | |
US4126804A (en) | Strip microchannel electron multiplier array support structure | |
CN107285618B (zh) | 一种实心光微通道阵列面板及其制备方法 | |
US3347649A (en) | Method of fusing single layer fiber optic strif | |
US7126263B2 (en) | Perforated mega-boule wafer for fabrication of microchannel plates (MCPs) | |
EP1615254B1 (fr) | Dispositif et procédé pour minimiser le flux de verre dans la fabrication d'une plaque à microcanaux | |
JP4801886B2 (ja) | 微小チャネルプレートの製造の間にガラスフローを低減するためのデバイスおよび方法 | |
US7109644B2 (en) | Device and method for fabrication of microchannel plates using a mega-boule wafer | |
KR100499866B1 (ko) | 요철모양의 금형을 이용한 mcp 제작 방법 및 장치 | |
US4101303A (en) | Perforate glass structures and method of making the same | |
JP4886452B2 (ja) | 延伸ガラス部材の製造方法、画像表示装置用スペーサの製造方法及び画像表示装置の製造方法 | |
JP3513101B2 (ja) | フォトニッククリスタルファイバの製造方法 | |
EP2063451A2 (fr) | Canaux MPC courbés | |
US20060035559A1 (en) | Method of fabricating spacers and method of installing spacers in flat panel device | |
WO1999060602A1 (fr) | Perfectionnement apporte a une galette de microcanaux | |
JP2001264565A (ja) | 石英ガラス系光導波路の製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR |
|
AX | Request for extension of the european patent |
Extension state: AL HR LT LV MK |
|
17P | Request for examination filed |
Effective date: 20060421 |
|
AKX | Designation fees paid |
Designated state(s): FR NL |
|
17Q | First examination report despatched |
Effective date: 20060831 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: 8566 |
|
17Q | First examination report despatched |
Effective date: 20060831 |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): FR NL |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed |
Effective date: 20090925 |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: SD Owner name: EXELIS INC. Effective date: 20120913 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: TP Owner name: EXELIS INC., US Effective date: 20120912 Ref country code: FR Ref legal event code: CD Owner name: EXELIS INC., US Effective date: 20120912 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: PLFP Year of fee payment: 12 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: NL Payment date: 20150726 Year of fee payment: 12 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20150717 Year of fee payment: 12 |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: MM Effective date: 20160801 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20160801 Ref country code: NL Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20160801 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST Effective date: 20170331 |