US3661581A - Method for photodepositing smaller size image screen areas for cathode ray tube from larger size mask apertures - Google Patents

Method for photodepositing smaller size image screen areas for cathode ray tube from larger size mask apertures Download PDF

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US3661581A
US3661581A US889238A US3661581DA US3661581A US 3661581 A US3661581 A US 3661581A US 889238 A US889238 A US 889238A US 3661581D A US3661581D A US 3661581DA US 3661581 A US3661581 A US 3661581A
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apertures
mask
size
image screen
light
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Nathan Feldstein
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RCA Licensing Corp
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RCA Corp
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    • 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
    • H01J9/14—Manufacture of electrodes or electrode systems of non-emitting electrodes
    • H01J9/142—Manufacture of electrodes or electrode systems of non-emitting electrodes of shadow-masks for colour television tubes
    • H01J9/144—Mask treatment related to the process of dot deposition during manufacture of luminescent screen

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  • ABSTRACT A method for producing a color kinescope having an image screen and a color selection mask having final-size apertures that are temporarily reduced in size for use as a photographic master in producing the image screen.
  • the method includes providing a substrate having apertures of final size; providing at one surface of the substrate a perforated layer of electroless deposition-initiating material, portions of the layer partially extending across the apertures; electrolessly depositing a suitable material at these portions of the layer to produce opaque light-barriers that define respective light-transmitting corridors; providing the image screen by photographic exposure through the corridors; removal of the light-barriers to restore the apertures to their original condition and provide the final mask; and incorporation of the mask and image screen into a kinescope.
  • the present invention relates to color kinescopes and particularly to a novel method for making a masked-type color kinescope wherein the image screen is produced with the use of the color selection mask having its apertures temporarily reduced in size.
  • the prior art discloses color kinescopes having both an image screen, which includes a multiplicity of groups of closely spaced elemental phosphor deposits, the elemental deposits of each of such groups emitting light of a different color when struck by an electron beam, and a color selection mask disposed between the image screen and the electron source of the kinescope.
  • Such masks including focusing and non-focusing masks
  • Such color selection masks may be of a planar or non-planar contour, the contour of a particular mask generally being similar to that of the image screen with which it is used.
  • the apertures of the masks can be circular or of some other cross-sectional configuration (e.g., slot-shaped).
  • the prior art discloses color selection masks having apertures which are individually larger than the respective phosphor areas of the image screens associated therewith.
  • Such larger (in comparison with the phosphor areas) apertures provide kinescopes exhibiting negative leaving tolerance (which is defined herein to be where the electron beam spots, as measured at the screen, are of greater size than respective individual phosphor areas of the screen) so that a larger proportion of each phosphor area is impinged than in previous kinescopes.
  • One method disclosed in the prior art for printing phosphor areas smaller than the bifunctional apertures of an associated non-focusing mask involves selecting the size of the light source used in screen printing so that, because of penumbra effects, a proper size phosphor area can be obtained by controlling the exposure time.
  • This method is not commercially attractive because the obtainable difference in size between the apertures and the phosphor areas is limited so that comparatively large differences therebetween (and, therefore, relatively large negative tolerances) are difficult, if not impossible, to achieve.
  • the phosphor dot size is a function of exposure time so that the process requires very carefully measured exposure times to obtain properly-sized phosphor dots.
  • This method is very sensitive to non-uniformities in the amounts of light striking various parts of the screen being printed so that the light distribution must be very carefully regulated to minimize size variations among the printed phosphor dots.
  • the electron beam spot size would be considerably smaller than that of the phosphor dots because of the focusing action on the beam and because of the aforementioned optical considerations.
  • the focusing masks usually have final-size apertures which are considerably larger than the individual phosphor areas associated therewith, so that larger electron beam spots can be obtained.
  • such focusing masks are not satisfactory for printing the phosphor areas of the image screen, as previously explained, because the larger final-size apertures would provide corresponding larger (and overlapping) phosphor dots.
  • opaque materials are deposited on focusing masks having final-size apertures (which are sufficiently large to provide an increase in electron transmissivity) so as to temporarily reduce the size of these apertures for the screen printing operation.
  • the opaque material is cataphoretically deposited on the mask, including the entire walls of the respective final-size apertures.
  • the preliminary mask thus produced is then used in the screen printing operation and the opaque materials are then removed from the preliminary mask to restore the finalsize apertures to the focusing mask.
  • the opaque material is removed prior to mounting the focusing mask in the kinescope envelope, as by subjecting the opaque material, in a fluid medium, to sustained compressional waves of a sonic or ultrasonic frequency.
  • Such a method requires expensive equipment for the application and removal of the opaque material and adds steps (i.e., those for such removal of the opaque material) to the kinescope manufacturing operation. Furthermore, this removal process can produce small particles of the opaque material, which particles might remain in the finished kinescope and lead to voltage breakdown and/or electrical shorting of the kinescope electrodes. Because of these drawbacks, this method is not completely commercially satisfactory.
  • the final-size apertures of a focusing mask are temporarily reduced in size in the following way.
  • the final-size apertures are produced in a metal sheet by etching the sheet through openings in a resist pattern located thereon, the etching being carried out such that parts of the resist pattern are undercut (i.e., the walls of the final-size apertures so produced are located beneath the resist pattern).
  • the final-size apertures are then temporarily reduced to a size required for printing the phosphor screen, by
  • a matching pattern of a resist material such as bichromated glue or shellac, is applied to each major surface of a sheet of conductive material.
  • Each pattern includes perforations of a predetermined size providing access to the conductive sheet.
  • This resist-covered sheet is then immersed in an etching solution to open, at accessible portions thereof, apertures of a final size desired for the focusing mask.
  • the mask etching is carried out so that parts of the resist pattern are undercut, these final-size apertures thereby being larger than the individual perforations in the resist pattern.
  • the resist-covered sheet containing the apertures is used as a master in the screen printing operation, the printing light rays passing through the being defined by the perforations in the resist patterns.
  • the resist patterns are subsequently removed so that the apertured conductive sheet can be used as a final focusing mask.
  • this method is not commercially satisfactory. While such a resist pattern with portions thereof overhanging the final-size apertures of a focusing mask (which pattern is required, in this third method, to be on the completed mask during the screen printing operation) can be provided on a focusing mask after the completion of such a mask, this cannot be done (by methods in the prior art) without considerable effort and expense. Therefore, the resist pattern is preferably provided on the abovementioned (unapertured) conductive sheet at the processed into sheets having suitable-size apertures.
  • the apertured sheet which is still in a comparatively hard condition, is annealed (e.g., at about 900 F for 10 minutes) to reduce its hardness and thereby facilitate the shaping thereof, such shaping being known in the art.
  • the apertured sheet is annealed and shaped, it is generally mounted on a frame and the thus-completed mask is used as a master for. printing the phosphor areas of the image screen in a manner known in the art (see US. Pat. No. 3,406,068).
  • the bichromated glue and shellac as well as comparable materials, deteriorate upon exposure to the annealing temperatures generally employed in the art so that this method is not desirable at least because it is generally not applicable to the production of masks by the above-outlined operations involving annealing.
  • This invention relates to a novel method for producing a color kinescope of the type comprising an image screen including a mosaicof phosphor and/or a light-absorbing matrix and a color selection mask having final-size apertures therein.
  • the color selection mask is produced by steps comprising the perforation of an electrically conductive substrate.
  • the apertures of the color selection mask are temporarily reduced in size to provide light-transmitting corridors and the temporary mask so-produced is used as a photographic master in screen printing.
  • the size reduction of the apertures is achieved by steps including the provision of a perforated catalytic layer of an electroless deposition-initiating agent at one of two opposed major surfaces of an apertured electrically conductive substrate, the apertures of the substrate being of final size and portions of the catalytic layer extending partially across the apertures.
  • a suitable material is thendeposited (by either electroless deposition or by a combination of electroless and electrolytic-deposition) at these portions of the catalytic layer to provide opaque light-barriers that define light-transmitting corridors that are smaller than the apertures of final size.
  • the abovementioned image screen is produced by steps including photographic exposure through the corridors of the temporary mask.
  • the light barriers and other materials, if any, are subsequently removed from the apertured substrate, the apertures thereof being restored to their original dimensions (i.e., the final-size), the resulting structure being the abovementioned color selection mask.
  • the target mask and the previously produced image screen are then incorporated into a color kinescope,
  • the advantages of the present invention are the ability to control closely and with relative ease the size of the light-transmitting corridors; the deposition of no material, or, at most, a relatively small amount thereof, at the walls of the substrate during the deposition of the material comprising the opaque light-barriers; the knife-edge configuration of the opaque light-barriers that are producible, which configuration provides better definition of the light beams in the screen printing operation, such a knife edge generally being available independent of the aperture configuration (i.e., regardless of whether the apertures are ellipsoidal, or cylindrical, spherical, or frusto conical in configuration); and the light-barriers are eliminable from the substrate with comparative ease and economy.
  • FIG. 1 is a side view, partly in axial section, of a mask type color kinescope including bothan image screen prepared with the use of a temporary mask made by the present invention and a kinescope mask produced from the temporary mask.
  • FIGS. 2 through 5 are fragmentary, transverse sectional views of a work piece schematically showing the various processing steps for the conversion thereof to a temporary mask according to the present invention.
  • FIG. 6 is a fragmentary transverse sectional view of a temporary mask made according to the steps shown in FIGS. 2 through 5.
  • FIG. 7 is a fragmentary sectional view of a temporary mask produced according to another embodiment of the present invention.
  • FIG. 8 is a fragmentary perspective view of the temporary mask shown in FIG. 6 in position for uses as a photographic master in preparing an image screen for a color kinescope.
  • FIG. 1 illustrates a color kinescope 10 produced by the novel method and temporary mask structure disclosed herein, which kinescope 10 includes a glass envelope 12 comprising a funnel portion 14 and a cap 16, which cap 16 includes a transparent faceplate 18.
  • an image screen 24 there is included on the image screen a light-reflective conductive layer (not shown) of aluminum, for example, which covers the phosphor areas and serves as an electrode.
  • the phosphor areas 20, are, for illustration purposes, exaggerated in size and proportion (as are other parts of FIG. 1 and the other figures) and shown as having a dot configuration, which dotsmay be arranged in the wellknown hexagonal dot pattern (not shown). Alternatively, each phosphor area may have a stripe configuration (not shown), these stripes being arranged in an alternating array of different color phosphors to provide a line screen.
  • the kinescope 10 further includes an electron gun for producing a number of electron beams and either electrostatic or magnetic deflection and convergence means, none of which are shown for simplicity.
  • a color-selection mask 30 (or mask electrode) which may be, for example, of the focusing or non-focusing variety, both of which are known in the art.
  • a suitable frame 32 or other means can be used to support the mask 30.
  • the mask 30 is understood to be of the non-focusing mask variety, which is operated at substantially the same potential as the screen 24 to form a field-free region therebetween.
  • the mask 30 is made from a thin sheet or band of conducting material (e.g., coldrolled steel) and has a plurality of apertures 34 of a desired final size therein. While the apertures 34 are, for simplicity, shown in FIG. 1 to be substantially circular in shape, apertures having other shapes may be used.
  • the mask may be of the grill type (not shown), having slot-shaped apertures.
  • the apertures 34 are related in size and position to respective phosphor areas 20 of the image screen 24.
  • the size relationship is such that, where the mask 30 is of the nonfocusing variety, each final-size aperture 34 is of such dimension as to be capable of passing an electron beam 21 whose dimensions, as measured at the screen 24, (i.e., the spot size of the beam) are at least substantially equal to, or preferably larger than the dimensions of the individual phosphor areas 20 upon which the electron beam impinges.
  • the electron beam spot size preferably is sufficiently large to provide a negative leaving tolerance but not so great that the electron beam impinges any ones other than the intended phosphor areas.
  • the size of the light spots produced during screen printing substantially exceeds that of the electron beam spots produced in the operation of the kinescope. This results in the size of the individual phosphor areas being considerably greater than the spot size of their associated electron beam so that the beam impinges only a portion of each phosphor area.
  • Such differences in size between the printing light spots and the electron beam dots are familiar to the art, the difference therebetween being attributable to the more extensive penumbra-umbra effect taking place in the screen printing process.
  • the final-size apertures 34 of the target mask 30 should be of such size that the electron beam spot is at least equal in size to and preferably larger than, the respective phosphor areas. Generally, it is preferred that the final-size apertures 34 exceed in size their associated phosphor areas 20.
  • the final-size apertures of a focusing-type mask are significantly greater in size than their respective individual phosphor areas whether the color tube is of the positive leaving tolerance type (i.e., the beam spot is smaller than a corresponding phosphor area) or the negative leaving tolerance type.
  • each aperture 34 is shown to correspond in position with only one phosphor area 20.
  • the kinescope 10 In the operation of the kinescope 10, electrons are emitted by the electron guns (not shown) and thereafter directed, by means known in the art, as electron beams 21 through the apertures 34 to impinge upon the phosphor areas 20. Because a larger electron beam spot is produced therein and impinges upon an entire individual phosphor area, the kinescope exhibits improved characteristics, such as increased image brightness and contrast, over prior art kinescopes.
  • one surface (e.g., 40) of a substrate of an electrically conducting material e.g., cold-rolled steel
  • the initiating material of the catalytic layer 46 can be palladium, copper, nickel, cobalt, or chromium, for example, the catalytic layer 46 being believed 6 to be comprised of finely divided nuclei of the initiating material.
  • a catalytic layer of palladium for example, can be produced by first bringing one major surface 40 of the substrate 42 into contact with an acidic stannous solution and then immersing the same major surface 40 in an acidic palladium solution.
  • the basic surface reactions believed to occur are: SnCl (HCl) S* S* SnCl and S* SnCl PdCl (I-ICl) S* Pd S where 8* denotes the substrate surface (e.g., 40) to which the layer 46 is to be applied.
  • the substrate 42 is made of iron, which is usually the case for color selection masks
  • a catalytic layer of palladium can be provided by a one-step operation of contacting one surface of the substrate with an acidic palladium chloride solution.
  • a first perforated pattern 48 of an etch-resistant material is formed on the catalytic layer 46.
  • the perforations 50 of the pattern 48 preferably are of substantially the same size as the light-transmitting corridors 64 (FIG. 6) used in the screen-printing operation, for reasons given below. This is done, for example, by providing a layer (not shown) of a suitable photosensitive resist material, such as bichromated fish glue, Shipley resist marketed by Shipley Co., Newton, Mass.
  • the catalytic layer 46 exposing the photosensitive resist layer to light passed through a suitable mask (not shown); and removing, as by washing with a suitable solvent, those areas of the layer of resist material that are soluble, this general process being known in the art.
  • the areas of the resist layer remaining on the substrate comprise the perforated pattern 48.
  • those portions of the catalytic layer 46 covered by the perforated pattern 48 remain at the major surface 40 and are not washed off or otherwise removed, while those portions of the catalytic layer 46 that are located beneath the areas of the resist layer which are removed may or may not be removed, it not being necessary in the preferred embodiment that these portions of the catalytic layer remain on the substrate 42. Portions of the substrate 42 are accessible through the perforations 50 of the first perforated pattern 48.
  • a second perforated pattern 52 of a suitable etch-resistant material is provided on the second major surface 44 of the substrate 42.
  • This second pattern 52 is optional and may be produced in the same way as the perforated pattern 48.
  • the perforations 54 of the second pattern 52 are in substantial register with the perforations 50 of the first pattern 48, the perforations 54 of the second pattern 52 preferably being larger than those of the first pattern 48. It is not necessary, however, that the perforations 54 of the second pattern be larger than those of the first; the perforations of the respective patterns may be of the same size or perforations 50 of the first pattern 48 may be larger.
  • the portions of the substrate 42 which are generally located in the regions between the perforations 50 and 54 of the respective patterns 48 and 52 are removed by etching, for example, with ferric chloride in a manner known in the art, through either or both of these perforations 50 and 54, to produce apertures 34 extending through the substrate 42 and in substantial register with the perforations 50 and 54.
  • the apertures 34 are of a final size (e.g., 14 mils) desired for the color-selection mask. While the apertures 34 are shown as having a double frustoconical configuration, other configurations may be used.
  • the present invention can be practiced with kinescopes employing mask apertures that are of a non-circular cross-sectional shape; e.g., slot-shaped apertures.
  • Etching is carried out such that there result both portions 58 of the catalytic layer 46 and areas 60 of the resist pattern 48 that partially extend across the various apertures 34, these portions 58 of the catalytic layer 46 being coextensive with the areas 60 and directly accessible through either or both of the perforations 50 and 54. Any parts of the catalytic layer 46 remaining on the substrate 42 atthe perforations 50 are eliminated by the etching operation.
  • the dimension of the apertures 34 preferably is significantly larger than the(final size) of the larger ones (i.e., 54) of the two types of perforations (50 and 54). It is believed that the portions 58 of the catalytic layer 46 remain on the areas 60 of the pattern 48 that partially extend across the apertures 34 because of an adsorption-type phenomenon.
  • electroless deposition is initiated by the portions 58 of the catalytic layer 46, the opaque deposits 62 partially extending across the apertures 34 and being substantially coextensive with the portions 58 of the catalytic layer 46 (and, therefore, areas 60 of the pattern 48).
  • the opaque deposits 62 provide opaque light-barriers that define light transmitting corridors 64 (FIG.
  • the corridor diameter should be about 12 mils.
  • the corridors 64 are substantially concentric with the apertures 50. Because the size of the perforations 50 of the first pattern 48 can be accurately controlled so that the perforations 50 are substantially equal to the desired corridors and because the opaque deposits are substantially coextensive with the areas 60 of the pattern 48, the size of the light-transmitting corridors 64 can be controlled with relative accuracy and ease via the control of the perforation size.
  • a variety of metals can be electrolessly deposited at the portions 58 of the layer 46, including nickel-phosphorous alloys; copper; cobalt; nickel; alloys of at least two of copper, cobalt, and nickel; and nickel-boron alloys, the last one being preferred primarily because of the lower activation energy required for the deposition thereof.
  • Electroless plating compositions are generally known in the art.
  • anaqueousbath for electrolessly plating a nickel-boron alloy has the formulation:
  • the opaque deposits may be produced with a nonmetallic material that lends itself to electroless deposition on the catalytic layer; also, the material that is electrolessly deposited may be non-opaque, this material subsequently being converted to an opaque condition.
  • the opaque deposits 62 may be increased in thickness to a sufficient dimension that allows the deposits to be self-supporting when the perforated pattern 48 is removed, such a self-supportable opaque deposit being shown as 62a in FIG. 6.
  • the thickened opaque deposit 62a can be produced by continuing the process of electrolessly depositing material on the exposed portions 58 of the catalytic layer 46 until a desired deposit thickness (e.g., )6 mil) has been achieved.
  • the resist patterns 48 and 52 have been removed by, for example, treatment with sodium hydroxide (in the case of fish glue resist) or with other suitable agents known in the art, to provide a temporary mask 70'.
  • the thickened metallic deposits 62a remain at the apertures 56 of the substrate 42 and provide a temporary reduction in the size thereof, the corridors 64 defined by those metal deposits 620 being substantially equal to the size desired for screen printing.
  • the temporary mask 70 may then be shaped to the desired contour and annealed in a manner known in the art.
  • the opaque deposits 62 of the temporary mask 70 can be increased in thickness by the electrodeposition (e.g., by electroplating) of a suitable material thereon.
  • electroplating is satisfactory but generally not preferred because additional material is deposited at the walls of the apertures 34, as illustrated in FIG. 7, the depth of such material on the walls being less than the thickness of the I thickened opaque deposit 62a comprising the light barrier.
  • the perforated patterns 48 and 52 of resist material may be allowed to remain on the temporary mask 70 during such screen printing in certain instances (e.g., where the temporary mask is not going to be annealed). Where it is allowed to remain on the temporary mask 70, the perforated pattern 48 carrying the portions 58 of the catalytic layer 46 provides support to the opaque deposit 62 so that there is less need for increasing the thickness of the deposit, the opaque deposit 62 acting as a light barrier.
  • the subsequent operation of screen printing utilizes the temporary mask 70 positioned in spaced relation with a suitable transparent substrate 80 (e.g., faceplate) and used as a photographic master to print the various elemental phosphor areas 82, 84, and 86 of the respective phosphor groups (red, blue, and green) on the substrate 80.
  • a suitable transparent substrate 80 e.g., faceplate
  • the printing process is known in the art (see, for example US. Pat. No. 3,406,068 to H. B. Law).
  • one surface 88 of the transparent substrate 80 is coated with a mixture (not shown) comprising a first one of the desired phosphors and a suitable photosensitive material and then exposed to a suitable light which is passed through and defined by the corridors 64 of the temporary mask 70.
  • the light-barriers of the temporary mask 70 have a knife-edge configuration, which particular configuration provides better definition of the light beams used in screen printing, there resulting therefrom more sharply defined phosphor areas. Because the light-barriers depend from the pattern areas extending over the apertures, opaque light-barriers having a knife-edge configuration are generally available regardless of the particular configuration (i.e., elliposoidal, cylindrical, spherical, or frusto-conical) of the final-size apertures.
  • Those portions of the phosphor coating (not shown) struck by the light rays are hardened, the unhardened portions of the coating being removed, by washing, for example, to leave a pattern (e.g., 82) of phosphor areas of a first color with the hardened resist material. This sequence of steps is repeated for the other phosphors.
  • The'hardened resist material is subsequently removed from the phosphor dots by baking or by chemical dissolution methods known in the art.
  • a temporary mask corridor 64 about 12 mils diameter and a final mask aperture 56 having a diameter of about 16 mils will respectively provide a phosphor dot of about 14 mils diameter and an electron beam spot size of about 17.8 mils diameter.
  • an electron beam source (not shown) intended for a particular phosphor group is located at each point 90, 92. or 94 so as to be in substantially the same spatial relation with the image screen (e.g., 24 of FIG. 1), as the light source (not shown) used for printing that particular phosphor group.
  • the paths followed by the light rays during printing and by the electrons during operation of the kinescope are indicated, for purposes of illustration, by the lines 96, 98, and 100.
  • the screen printing operation may include providing, with the use of the temporary mask 70 disclosed herein, a light-absorbing matrix (e.g., 23 of FIG. 1) of an opaque, non-lightreflective material to the image screen (e.g., 24 of FIG. 1).
  • a matrix provided to an image screen is considered to be included in the term image screen.
  • This can be done, for example, by coating a surface of the bare transparent substrate (e.g., 18) with a relatively translucent mixture (not shown) comprised of a material which has a relatively low light absorption and is convertible to a condition which is more light-absorbing (e.g., manganese oxalate or manganese carbonate, which can be converted from a comparatively translucent condition to an opaque,
  • a positive-type photosensitive resist i.e., one which is soluble where exposed to light and remains insoluble elsewhere
  • exposing the coating to suitable light passed through the corridors of the temporary mask.
  • the unhardened portions of the coating are washed away and the relatively low light-absorbing material of the remaining portions of the coating is converted to its light-absorbing condition.
  • the phosphor areas (e.g., 82, 84, and 86 of FIG. 8) are then printed at openings in the matrix, as described above.
  • the phosphor areas may, if desired, be somewhat larger than the openings of the matrix so that portions of the respective phosphor areas are disposed on the matrix itself.
  • the efiective size of such phosphor areas is, therefore, equal to the size of their respective matrix openings.
  • size is defined to be the effective size thereof.
  • the phosphor areas may be printed before the conversion of the material to its light-absorbing condition. Alternatively, the phosphor areas may be printed before the provision of the matrix, the preliminary mask being used for both of these operations (i.e., matrixand phosphor areaproduction).
  • a light-absorbing matrix can, with a temporary mask, be provided to a transparent substrate, with the subsequent phosphor printing being done by applying a phosphor-photoresist mixture to the substrate surface on which the matrix is located and, then, exposing the mixture to light from a source located on the side of the substrate opposite the surface thereof bearing the matrix. The light passes through and is defined by the matrix openings.
  • the opaque deposits 62a comprising the light barriers are eliminated from the temporary mask 70 by electro-chemical stripping or by chemical etching, for example, using reagents and steps known in the art.
  • the elimination of the opaque deposits 62a restores the apertures 34 to their original size (i.e., their final size), the resulting apertured structure constituting the color selection kinescope mask (e.g., 30 in FIG. 1).
  • the kinescope mask and the screen are subsequently incorporated into a color kinescope (FIG. 1).
  • the advantages of the present invention are the ability to control closely and with relative ease the size the light-transmitting corridors; the deposition of no material, or, at most, a relatively small amount thereof, at the walls of the substrate apertures during the deposition of the material comprising the opaque light-barriers; the producibility of light-barriers having a knife-edge configuration, which configuration provides better definition of the light beams in the screen printing operation, such a knife edge generally being available independent of the aperture configuration (i.e., regardless of whether the apertures are ellipsoidal; cylindrical; spherical; or frusto-conical in configuration); and the eliminability of the light-barriers from the substrate with comparative ease and economy.
  • Iclaim 1 In the manufacture of a cathode ray tube including an image screen and a shaped apertured mask having a plurality of final-size apertures therein, the method of producing said image screen comprising a. providing a sheet having opposed major surfaces and said plurality of final-size apertures extending between said surfaces,
  • step (e) includes removing said etch-resistant material.
  • an electrically conductive substrate having two opposed major surfaces and a perforated catalytic layer of an electroless deposition-initiating material disposed at one of said surfaces, said substrate including said plurality of final-size apertures extending between said surfaces, said perforations in said catalytic layer, being smaller than said apertures such that portions of said catalytic layer partially overhang said apertures;
  • said light opaque material is selected from the group consisting essentially of nickel; copper; cobalt, nickel-phosphorous alloys; nickel-boron alloys; and alloys of at least two of nickel, copper, and cobalt.

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US889238A 1969-12-30 1969-12-30 Method for photodepositing smaller size image screen areas for cathode ray tube from larger size mask apertures Expired - Lifetime US3661581A (en)

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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3738233A (en) * 1972-01-17 1973-06-12 Zenith Radio Corp Camera process for color tube screen printing
US3822454A (en) * 1972-11-30 1974-07-09 Gte Sylvania Inc Method of fabricating a color cathode ray tube
US3863086A (en) * 1972-11-30 1975-01-28 Gte Sylvania Inc Coated pattern mask for use in forming a color CRT screen structure and method for coating the mask
US3955980A (en) * 1974-11-04 1976-05-11 Zenith Radio Corporation Method for making a color selection mask for a color cathode ray tube
US3986073A (en) * 1971-08-18 1976-10-12 U.S. Philips Corporation Luminescent screen of a color television tube
US3993516A (en) * 1974-10-07 1976-11-23 Zenith Radio Corporation Method of controlled etching in the manufacture of a color selection mask for a color cathode ray tube
US4404060A (en) * 1981-05-08 1983-09-13 Siemens Aktiengesellschaft Method for producing insulating ring zones by galvanic and etch technologies at orifice areas of through-holes in a plate
US4534744A (en) * 1983-05-02 1985-08-13 Burroughs Corporation Display panel and method of making it
US4651051A (en) * 1985-07-05 1987-03-17 Rca Corporation Cathode-ray tube having a focusing color-selection structure and a viewing screen formed therefrom
US4778738A (en) * 1986-08-14 1988-10-18 RCA Licensing Method for producing a luminescent viewing screen in a focus mask cathode-ray tube
US9986642B2 (en) * 2015-07-22 2018-05-29 Ibiden Co., Ltd. Method for manufacturing printed wiring board and printed wiring board

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63100065U (de) * 1986-12-17 1988-06-29

Citations (1)

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US3231380A (en) * 1960-11-14 1966-01-25 Rca Corp Art of making electron-optical reticles

Patent Citations (1)

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US3231380A (en) * 1960-11-14 1966-01-25 Rca Corp Art of making electron-optical reticles

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3986073A (en) * 1971-08-18 1976-10-12 U.S. Philips Corporation Luminescent screen of a color television tube
US3738233A (en) * 1972-01-17 1973-06-12 Zenith Radio Corp Camera process for color tube screen printing
US3822454A (en) * 1972-11-30 1974-07-09 Gte Sylvania Inc Method of fabricating a color cathode ray tube
US3863086A (en) * 1972-11-30 1975-01-28 Gte Sylvania Inc Coated pattern mask for use in forming a color CRT screen structure and method for coating the mask
US3993516A (en) * 1974-10-07 1976-11-23 Zenith Radio Corporation Method of controlled etching in the manufacture of a color selection mask for a color cathode ray tube
US3955980A (en) * 1974-11-04 1976-05-11 Zenith Radio Corporation Method for making a color selection mask for a color cathode ray tube
US4404060A (en) * 1981-05-08 1983-09-13 Siemens Aktiengesellschaft Method for producing insulating ring zones by galvanic and etch technologies at orifice areas of through-holes in a plate
US4534744A (en) * 1983-05-02 1985-08-13 Burroughs Corporation Display panel and method of making it
US4651051A (en) * 1985-07-05 1987-03-17 Rca Corporation Cathode-ray tube having a focusing color-selection structure and a viewing screen formed therefrom
US4778738A (en) * 1986-08-14 1988-10-18 RCA Licensing Method for producing a luminescent viewing screen in a focus mask cathode-ray tube
US9986642B2 (en) * 2015-07-22 2018-05-29 Ibiden Co., Ltd. Method for manufacturing printed wiring board and printed wiring board

Also Published As

Publication number Publication date
DE2063578A1 (de) 1971-07-15
CA942598A (en) 1974-02-26
NL7018948A (de) 1971-07-02
GB1332000A (en) 1973-09-26
FR2074381A5 (de) 1971-10-01
JPS502355B1 (de) 1975-01-25

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