Abstract: A gas scrubber employing liquid droplets injected into a flowing gas stream at a higher velocity than the gas velocity, having means to create a gradient of increasing pressure downstream from the droplet injection site, which gradient decelerates the gas and thereby increases the velocity of the droplets relative to the gas, thus increasing the total path length of the droplets through the gas, so as to allow substantial increase of scrubber collection efficiency without use of increased scrubber size or increased liquid droplet flow rate.

Abstract: A high performance flatus gas filter assembly, and a body waste collection pouch with which it may be used, along with a method for making such an assembly, are disclosed. The assembly includes a filter pad having first and second layers of deodorizing filter media with an imperforate gas and odor barrier layer sandwiched therebetween for blocking the direct flow of gases between the opposing inner faces of the filter layers. An envelope of liquid and gas impermeable material defines a chamber for enclosing the pad. The envelope has walls with first and second openings communicating with central portions of the first and second filter layers, and defines a peripheral space about the pad to permit the outward flow of flatus gases from the peripheral edge surface of one of the filter layers inwardly into the peripheral edge surface of the other of the filter layers.

Abstract: De-entrainment devices for effectively removing entrained liquid from a vapor stream are disclosed. These de-entrainment devices are effective in distillation columns and other apparatuses comprising vapor-liquid contacting devices. Particular representative applications for these de-entrainment devices are in distillation (or fractionation) columns having co-current contacting modules, in which liquid and vapor enter into co-current flow channels of the modules. The de-entrainment devices can be used, for example, with non-parallel contacting stages or other types of high capacity trays.

Abstract: The present invention provides an apparatus for the vaporization of materials that releases active constituents for inhalation without the creation of harmful byproducts such as carcinogens associated with combustion and inhalation of substances.

Abstract: A dust suppression system for suppressing dust associated with a movement of dust producing material along an open conduit may include a hood assembly positioned adjacent the open conduit so that the hood assembly defines an interior chamber that is exposed to the dust producing material contained within the open conduit. A baffle member mounted to the hood assembly divides the interior chamber into an inlet chamber and an outlet chamber. A venturi assembly having an inlet end and an outlet end is mounted to the baffle member so that the inlet end of the venturi assembly is exposed to the inlet chamber and so that the outlet end of the venturi assembly is exposed to the outlet chamber. A pressurized fluid provided to the venturi assembly causes the venturi assembly to pull dust laden air contained within the inlet chamber to the outlet chamber, the fluid combining with a portion of the dust suspended in the dust laden air to suppress a release of dust into a surrounding atmosphere.

Abstract: A filtration device particularly for use with vacuum cleaners used for collection of fine particles which tend to clog porous solid filters. The device utilizes readily replaceable water as a filtration medium with air being forced into the water then released for additional multiple water contacts. The device further includes horizontal baffles with air access apertures therein which are positioned above the surface of the water, with a vacuum being applied to the area. This redirects particle laden air into filtration contact with water multiple times wherein filtration efficiency is in excess of 99%.

Abstract: An apparatus for controlling dust generated during a material transfer operation includes an environmental enclosure surrounding a conveyor bed, the enclosure having a series of baffles creating scrubbing chambers in which dust particles are agglomerated by a fog or mist. The baffles have ports allowing positive airflow under the influence of the moving material and of the conveyor bed so that airborne dust particles impact and adhere to the wet baffle surface. Accumulated dust in the form of a wet sludge eventually drops onto the material on the conveyor and is carried out of the system.

Abstract: A resist material curable by irradiation with high energy radiation such as electron beams, X-rays, ion beams, neutron beams, .gamma.-rays or deep ultraviolet light but substantially non-curable by irradiation with light having a wavelength of about 300 nm or more, the resist material comprising, as a main component, a solvent-soluble polymer containing an ethylenically unsaturated double bond, the polymer being obtained by reacting (a) a polymer having a plurality of oxirane rings therein and (b) a monomer containing (i) at least one ethylenically unsaturated double bond and (ii) one functional group capable of opening the oxirane rings, and then opening the unreacted oxirane rings.

Abstract: Fabrication of fine dimensioned circuits, e.g., VLSI includes at least one lithographic step dependent upon members of a particular category of polymer resists. Such resists, generally negative acting, are characterized by high contrast due to unusually narrow molecular weight distribution of the polymer molecules. This distribution is in turn dependent upon choice of a base polymer which is itself characterized by narrow molecular weight distribution due to "living polymerization" (solution anionic, polymerization). Functionalization of such base polymer is designedly such as to retain narrow distribution. Chlorinated polystyrene is exemplary of the resist category.

Abstract: A semiconductor structure from which various types of active semiconductor devices can be formed is made of a semiconductor island on a transparent substrate, having thereon an electrically insulating layer of a protective material, such as silicon dioxide, which extends onto and covers the sides of the semiconductor island. The protective layer can either cover only the sides of the semiconductor island or extend over the top edge of the island. The protective layer is made by etching through a photoresist mask made of a negatively reacting photoresist which is formed by exposure to irradiation from beneath the uncovered surface of the substrate, whereby the thickness of the silicon island and the flux density of the irradiation are selected so that for a particular duration, the irradiation is completely attenuated by the semiconductor island.

Abstract: Irradiation of collected S.sub.4 N.sub.4 decomposition products with light or radiation in the .gamma. to visible range enhances the initiation of polymerization of the decomposition products to produce polysulfur nitride, which is typically conductive and usually referred to as (SN).sub.x. Irradiation of a masked coating of collected S.sub.4 N.sub.4 decomposition products and completion of polymerization thereof and removal of non-irradiated, non-polymerized portions thereof will result in an electrically conductive coating disposed in a preselected pattern. S.sub.4 N.sub.4 decomposition products may also be dispersed in a matrix, e.g. a photographic emulsion which is transparent or partially transparent to light, or which may be rendered partially or selectively transparent or opaque. This might be useful, for example, for imaging applications, or for producing a selectively transparent pattern for subsequent photoinduced initiation of polymerization of the S.sub.4 N.sub.4 products.

Abstract: A photosensitive coating composition comprising reaction products of a monoethylenically unsaturated carboxylic acid and two different epoxy polymers; a polyethylenically unsaturated compound; and photoinitiator; and method of employing the same.

Abstract: A hybrid integrated circuit package and a method for fabricating the package. The package comprises a ceramic substrate having a blank metallization and feedthroughs screen printed thereon. A ceramic seal ring is joined to the substrate to form the side walls of the package. The substrate metallization is plated with nickel and gold and external leads are brazed to the ends of the feedthroughs. As such the package is suitable for use with a large number of different integrated circuits. The package can be adapted for use with a particular integrated circuit function by selectively patterning the blank substrate metallization. This is accomplished by laminating a preformed piece of dry film photoresist material to the package bottom. This piece of photoresist is then exposed through a photographic mask using a collimated light source.

Abstract: A high aspect ratio structure (with a large height-to-linewidth ratio) is formed on a substrate by means of two resist layers with different kinds of radiation to which they are sensitive, respectively, with an actinic radiation sensitive resist below and an electron sensitive resist above. In addition, a metallic film is shaped by means of exposure of the upper layer of resist to form a metallic mask through which the lower layer of resist is exposed. Exposure may be performed by a "subtractive" technique or an "additive" technique. In the case of the subtractive technique, the substrate is coated by a first actinic resist above which are deposited first a metallic film and then a top layer of electron resist. The top resist layer is exposed and developed and the metal layer is etched so the lower resist can be exposed and developed with the pattern formed in the metal, with the pattern shape originally exposed in the top layer of resist extending down to the substrate.

Abstract: This invention relates to a photo-cross-linkable polymer containing units each having a 2-pyridone side group. The invention also relates to a photosensitive copying material including the novel photo-cross-linkable polymer.

Abstract: The addition of N-methylol acrylamide as an accelerator to casein-based aqueous photoresist compositions reduces the baking temperature required to render the developed resist etch resistant.

Abstract: A technique for providing interconnections between pairs of contact points associated with a conductive line pattern by the use of an interconnection defining tool which is selectively alignable with respect to the conductive line. The conductive line pattern comprises at least one conductive line which is either continuous or shows interruptions, and from which lines branch off to the contact points. The tool is adapted to the conductive line and consists of a row of elements, the distance between which is dimensionally related to the distance between the branch-offs. After the tool has been adjusted to the conductive line in accordance with the respective connections, the elements of the tool are used for interrupting or connecting the conductive line at predetermined positions.

Abstract: By the process of this invention, two layer printed circuits having conductive interconnections are prepared by applying a photoadhesive layer to a substrate bearing an electrically conductive circuit pattern, exposing the photoadhesive layer to a circuit image related to the circuit pattern to produce adherent circuit image areas having segments thereof, e.g., pad areas, overlying segments of the electrically conductive circuit pattern, applying metal, alloy or plating catalyst powder, e.g., copper, to the adherent image areas, exposing the metallized or catalytic circuit pattern to an image of the overlying segments of the previous circuit patterns, removing the overlying segment areas of the photoadhesive layer with a suitable solvent, and treating the metallized surface by plating, e.g., electrolessly plating, or by soldering. Multilayer printed circuits can also be prepared by repeating these steps with additional layers of photoadhesive material adhered to underlying printed circuits.

Abstract: A photoreactive composition containing an effective amount of a polymer which includes as a recurring structure: ##STR1## wherein Ar is a bivalent aromatic radical, and M is selected from the class consisting of hydrogen, alkali metal, ammonium, and substituted ammonium. These compositions are useful in a wide variety of photochemical and photomechanical processes and are particularly suited for use as photopolymers, photoinitiators and photosensitizers in light sensitive coatings of presensitized lithographic plates.

Abstract: This invention pertains to an electron beam resist method for forming a surface relief pattern in a poly(olefin sulfone) layer wherein the polymer layer is useful as a sputter etch mask for transferring the surface relief pattern into a metal layer. The surface relief pattern is formed using poly(3-methyl-1-cyclopentene sulfone) as the poly(olefin sulfone) layer and using a mixture of 2-methylcyclohexanone and 2-methylcyclohexanol or a mixture of benzene and 2-methylcyclohexanol as the developer for the poly(3-methyl-1-cyclopentene sulfone) layer.

Abstract: An improved electroluminescent display panel having an X-Y array of display elements upon a planar insulating substrate. Integral thin film transistor circuit elements and drive signal buses are interconnected on the panel with individual electroluminescent electrodes covering a large area of the panel to increase the active display area. The electroluminescent electrode is a multilevel electrode with a first level portion disposed on the insulated substrate, a second level electrode portion disposed over an insulative polymerized layer which covers the thin film circuit areas and the drive signal buses, and a connecting electrode portion which extends between the first and second level electrode portions.

Abstract: A method of selectively nickeling a layer of polymerized polyester resin is described. Patterns of electrically conducting nickel are produced on the resin surface by etching the surface of the resin prior to covering the etched surface with a patterned layer of unetched resin which exposes the etched resin in the regions in which metallization is to occur. A palladium plating solution followed by an immersion boron-nickel bath provide the metalization on the etched regions of the resin.

Abstract: Photographic masks, suitable for reproduction in a photoresist layer -- by exposure of the latter to actinic light under the mask, and development of the photo-resist image -- of the pattern of a microelectronic component or device, are made by exposure to light in accordance with an original (especially by contact exposure under a primary mask) containing the pattern to be reproduced, of light-sensitive material having a flat, rigid, dimensionally stable transparent base such as glass and a thin (e.g. 0.

Abstract: Glass photomasks having a stained pattern within the glass for use in photolithographic processes are made by injecting stain-producing ions, preferably silver and/or copper ions, into a glass substrate from a film by electron bombardment, which also serves to reduce the injected ions to their elemental state and to agglomerate the atoms to colloidal coloration centers. The stained areas of the glass are patterned by carrying out the electron bombardment through a developed photoresist, or by using a focused electron beam moving along a controlled locus.

Abstract: A method is disclosed for dicing individual or groups of diode mesas fabricated upon a single metal heat sink. The undiced device is placed diode mesas down upon a transparent glass plate with the mesas protected in wax. A first mask is positioned upon the opposite side of the plate by alignment with the diode mesas as seen through the plate. Portions of the first mask extend on the plate beyond the edges of the wax and heat sink. A second etching mask is then fabricated upon the bottom of the heat sink by exposing a layer of photoresist through a mask having the same grid pattern as the first mask and which is aligned with the portions of the first mask seen through the glass plate beyond the edge of the heat sink. The diode mesas are etched apart by spraying an appropriate etchant through apertures in the etching mask.

Abstract: The density of defects formed during the exposure of a positive resist layer, due to the loss of photoresist in circular areas is reduced by the addition of an antistatic agent. The resist layer includes a phenol-formaldehyde resin and an o-diazoquinone photoactive compound and a suitable antistatic agent is a 2-alkyl-N-hydroxyethyl imidazolinium salt.

Abstract: Carriers forming strips for semiconductor integrated circuit chips. The carrier consists basically of a flexible tape, such as a polyimide. A conductive sheet, such as a copper sheet, is initially prepared to form a lead circuit on one surface and a bump circuit on the other. This metal sheet may be gold plated. Subsequently, a layer of polyimide is applied to the lead circuit side and both the polyimide sheet and the opposite bump circuit are covered with a metal sheet, such as copper. A photoresist layer is put over the copper and is suitably illuminated and developed to provide apertures through which the copper can be etched to expose the polyimide sheet. This takes place over the windows or openings adjacent the bumps for the application of a heat ram as well as for the sprocket holes used for precisely aligning the carrier with the to-be-associated semiconductor chips. Finally, openings may also be provided to separate adjacent carrier strips from each other.

Abstract: Disclosed is a method of forming patterned electron beam resists from polymers that undergo energy intensity or electron dosage dependent reactions. Upon the introduction of sufficient energy, the polymer generates two reactive species that react with each other. However, with a lower amount of energy, the polymer generates only one reactive species. A thin film of the dosage dependent polymer is applied to a support and is subjected to a programmed electron beam scan. The electron beam irradiates a portion of the polymer film according to the programmed pattern and furnishes enough energy in the path of the beam to cause the polymer to cross link where directly irradiated, thus causing the polymer to become insoluble in certain solvents. The portion of the polymer adjacent the directly irradiated portion is subjected to electrons back-scattering from the surface of the support, which electrons are a small percentage of the total beamed at the polymer.

Abstract: A photopolymerizable coating over a diazo resin provides a high-speed lithographic plate or photoresist while improving the printing life of the plate while making its development simpler than that of most other photopolymer plates. The photopolymer is a cinnamoylated polyvinyl alcohol resin which is placed over a diazo based material.

Abstract: A germanium mesa transistor is fabricated having an epitaxially grown base region and an aluminum alloy emitter in the epitaxially grown layer spaced from the collector junction, and having a gold-comprising base electrode surrounding the emitter and closely spaced therefrom. The gold contact is formed by photolithographic and selective etching techniques, followed by the formation of the aluminum emitter, which is also formed by photolithographic and selective etching techniques. A key step is the selective removal of the aluminum from the germanium wafer without disturbing the gold contact.

Abstract: An improvement in the process of manufacturing integrated circuits to enhance the yield, including the steps of tracking which of the individual dies on a photomask or related series of photomasks has produced a predominance of defective chips on the semiconductor wafer, then correcting the die images on the master photomasks and then producing new working masks. This procedure may be repeated several times, each time reducing the number of defect-bearing die images on the photomask and thereby providing a means by which a semiconductor device manufacturer can obtain better yields.

Abstract: Negative resist compositions are based on carbonaceous polymers with substituent branches containing epoxy groupings. Exemplary materials which include, for example, a copolymer of glycidyl methacrylate and ethyl acrylate in which epoxy groupings are unesterified show high sensitivity, for example, to electron radiation and to X-rays. Resolution is sufficient to permit expedient fabrication of detailed resist patterns for integrated circuits. High adherence permits use of acid or base reagents and thermal stability permits use of ion milling for circuit fabrication.

Abstract: This invention pertains to a method for forming a surface relief pattern in a metal layer which comprises forming a wet poly(olefin sulfone) layer on the metal layer, forming a surface relief pattern in the wet poly(olefin sulfone) layer, and sputter etching the surface relief pattern from the wet poly(olefin sulfone) layer into the metal layer.

Abstract: Resist images are hardened so that they are flow resistant at elevated temperatures by coating the image with a layer of a quinone-diazide hardening agent and heating the image to cause the agent to react with the resist and form a hardened image.

Abstract: A polymeric resist mask composition thinly coated on a semiconductor substrate, wherein the prescribed portions of said resist mask are exposed to high energy rays such as electron beams, X-rays or ultraviolet rays for degradation, and the degraded portions of the resist mask are removed by an organic solvent to present a prescribed resist mask pattern on the semiconductor substrate, which comprises a halogenated polymethacrylic ester whose composition is expressed by the general formula ##STR1## (WHERE R denotes a halogenated alkyl radical including a halogen element selected from the group consisting of fluorine, chlorine and bromine, and at least one fluorine atom in case said radical contains chlorine or bromine and n indicates an average polymerization degree of 100 to 20,000) and an organic solvent for said halogenated polymethacrylate.

Abstract: A graphic aid and method and system associated therewith are provided for producing aligned patterns in registry such as circuit board patterns and portions thereof. Certain features of the invention make it especially useful in fabricating multiple patterns which are discrete but in registry and in which one pattern represents a portion common with all the rest. Such a system is exemplified by two sided or multilayer circuit boards. The aid includes a diaphanous layout sheet whereon one or more sets of light absorptive pattern elements and reflective marks are arranged to conform to desired circuit patterns for the surfaces of a printed circuit board. A light absorptive background sheet is also provided and it is selectively positioned behind the layout sheet, to produce visible contrast with the reflective pattern marks thereon.

Abstract: A method of depositing patterned thin films on an integrated circuit substrate which comprises first forming a layer of positive photoresist material on the substrate and then heating to partially cure the photoresist while maintaining the surface of the photoresist interfacing with the substrate at a lower temperature than the opposite surface of the photoresist which is being exposed to the heat. As a result of this expedient, the upper or exposed portion of the photoresist layer is cured to a greater extent than the lower portion at the interface with the substrate. Then, the photoresist layer is exposed to a selected pattern of light, after which developer for the photoresist material is applied.

Abstract: A method for producing a photomask, which comprises exposing and development-processing a photographic light-sensitive material comprising a transparent support having thereon a masking layer and a silver halide emulsion layer to thereby form a silver image, bleaching the silver image with a bleaching solution containing hexavalent chromium ion, heating in the presence of oxygen to imagewise uncover the masking layer, etching away the uncovered masking layer, and then removing the emulsion layer at the non-image areas to uncover the masking layer corresponding to the non-image areas.

Abstract: A semiconductor device fabricated by forming a layer of semicured polyimide resin on a semiconductor body, forming a photoresist layer having a prescribed pattern on said semicured layer, immersing in an etchant consisting of hydrazine and ethylenediamine to said semicured layer through said prescribed pattern, whereby said semicured layer is precisely etched according to said prescribed pattern and prescribed surfaces of said semiconductor body are exposed, curing said semicured polyimide so as to form a layer of said polyimide resin, forming a metal layer on the surface of said polyimide and the prescribed surfaces of said body, and selectively etching said metal layer so as to form a prescribed pattern.

Abstract: A process for producing fine structures having an order of magnitude of 1 .mu.m without a loss of dimension relative to a mask on a base such as a semiconductor device having electrode structures characterized by providing a base having a surface which is either etchable or is provided with an auxiliary etchable layer, providing a mask on the surface, which mask has openings corresponding to the fine structure of material to be applied on the surface, providing an etching agent which attacks the surfaces of the base without attacking the mask, etching the uncovered portions of the base until an under-etching of predetermined width exists beneath the edges of the mask, depositing the layer of material on the entire surface, controlling the amount of depositing so the layer of material being deposited on the mask and on the etched surfaces of the base are not in contact with each other, and subsequently removing the mask with the layer of material deposited thereon.

Abstract: An organic solvent- or water-developable photosensitive composition consisting essentially of a ring-opened polymer or copolymer of at least one norbornene derivative having at least one substituent selected from the group consisting of ester groups, nitrile groups, carboxyl groups, amide groups, imide groups, hydroxyl groups, halogens and carboxylic acid anhydride groups, or a ring-opened copolymer of at least one said norbornene derivative and at least one cycloolefin other than cyclohexene, or a hydrolysis product of said ring-opened polymer or copolymer and a photosensitive crosslinking agent or photosensitizer soluble in organic solvents or water. The above photosensitive composition is excellent in sensitivity, adhesion and stability.

Abstract: In a wholly additive process for depositing a patterned metal layer on an insulating substrate, the sensitized and activated substrate is coated with photoresist; a desired pattern is formed in the photoresist layer by exposing it to a mask and developing it using conventional techniques; the patterned surface is then contacted with a second developer solution containing the activator; a metal pattern is deposited by electroless metal plating; and the photoresist is removed.

Abstract: The invention relates to a method of making a negative photoresist image on a substrate, where a normally positive working photoresist material containing 1-hydroxyethyl-2-alkyl-imidazoline is applied to a substrate, image-wise exposed with actinic radiation, heated, and blanket exposed to actinic radiation. The material which was not exposed originally is then removed with a solvent to give a negative image.

Abstract: Articles exhibiting a micropattern carried by a surface of a support, typically microdevices comprising a micropattern of a functional material on or in a substrate of a dissimilar material, are produced by a method employing a microsubstrate comprising a substrate base, a protein layer which comprises at least a compressed monolayer of a denatured non-fibrous protein on the base, and a masking film overlying the protein layer, the material of the masking film being such as to be modified by radiant energy so as to be removable from the protein layer where irradiated. The method is flexible in the sense that it is possible to proceed via either a positive or a negative of the desired micropattern and to build a more extensive, or more complex, micropattern from an initial relatively simple micropattern.

Abstract: The adhesion between inorganic oxides and photoresistant polymers is improved by, prior to contacting the oxide and the polymer, treating the oxide with(a) an aminosilane of the formulae R.sub.3 SiNHR' and R.sub.2 Si(NHR').sub.2 ; or a polysilazane, with the exception of hexaalkyldisilazanes, having 0.8 to 3 organic groups per silicon atom, and having units of the formulae R.sub.3 Si(NH).sub.0.5, R.sub.2 SiNH, RSi(NH).sub.1.5 or Si(NH).sub.

Abstract: Micropattern devices, such as electronic microcircuits, are produced by establishing on a substrate base a film of resist material, such as a polymeric film, containing dispersed therethrough a substantial proportion of an enzyme and then producing a pattern of a metal by reactions depending upon presence of the enzyme.

Abstract: A printing plate comprising a support, reliefs formed thereon as an image area, and from about 20 to about 4,000/cm.sup.2 small projections thereon in non-image areas, the height of the reliefs being at least 0.05 mm larger than that of the small projections, and a method for making a printing plate which comprises:(a) superimposing a photosensitive resin layer having a thickness of at least 0.06 mm on a support, which is at least semi-transparent to actinic light, in intimate contact therewith;(b) exposing the resulting assembly to actinic light through an image-bearing transparency from the side of the photosensitive resin layer;(c) exposing the assembly to actinic light through a dot-image-bearing transparency having a transparent halftone dot area in a proportion of 1 to 40% from the side of the support to thereby form reliefs on the support, as image areas, and a number of small projections having a height of at least 0.

Abstract: Method and apparatus for producing a design on a flat surface by etching and/or selective plating. The design is transferred to the flat surface by progressively projecting successive narrow transverse images of the design from a rectangular transparency and progressively rotating the flat surface about an axis such that the narrow images of the design are successively projected upon and received by corresponding radial portions of the flat surface which is or has been photosensitized. The design appears on the flat surface in a foreshortened circular form. The flat surface is adapted for subsequent formation into an arcuate surface bearing the design in relatively undistorted form.

Abstract: A positive relief image is produced by coating a substrate with a layer of a copolymer containing about 90-98 mole percent of polymerized lower alkyl methacrylate units and about 2-10 mole percent of polymerized lower haloalkyl methacrylate units, heating the layer to cause cross-linking between polymer chains by removal of hydrogen halide, patternwise exposing the layer with high energy radiation such as a scanning electron beam, and removing the exposed portion of the layer with a solvent developer.The purpose of this abstract is to enable the public and the Patents and Trademark Office to rapidly determine the subject matter of the technical disclosure of the application. This abstract is neither intended to define the invention of the application nor is it intended to be limiting as to the scope thereof.

Abstract: This disclosure depicts a low cost method of making curved color cathode ray tube shadow masks having interregistrable beam-passing aperture patterns. The method comprises providing flat mask master means and curved mask master means, the flat and curved master means having correlative master stencil patterns. Using the flat mask master means, there is photochemically formed in at least one side of a flat shadow mask blank a pattern of blind mask apertures whose individual blind aperture location is related to the end-product mask aperture location and whose individual blind aperture size, at least in a direction corresponding to the direction of electron beam scan across the mask, is greater than the desired end-product mask aperture size by a predetermined misregister tolerance value. The flat mask blank is precision-shaped into a predetermined three-dimensional configuration with the pattern of blind apertures referenced to indexing means defined by the mask.