Abstract: In the manufacture of a printed circuit board a sacrificial tin-lead layer is deposited on the surface of the board by electroplating. Holes are then formed in the board by UV laser ablation. Debris from the ablation process is adsorbed on the sacrificial layer. The sacrificial layer is then removed by means of a chemical stripping process, along with the debris.

Abstract: The object of the present invention is to provide a cold cathode field emission display whose resolution is not limited by the provision of individual ballast resistors for each pixel or by the wiring system used to deliver voltage to the cold cathodes. This has been achieved by providing additional layers beneath the cold cathodes arrays so that said resistors and voltage delivery systems are located directly below the cold cathode arrays instead of alongside of them. Six different embodiments of the invention are described.

Abstract: The fluid handling devices are capable of accurately handling substantially continuous fluid flow rates as low as about 0.01 cc/day. The devices are so miniaturized, corrosion-resistant and non-toxic that they are suitable for being implanted in the human body; and are capable of being mass produced at costs so low, by using micromachining techniques, such as etching, that they may be considered to be disposable. The devices are either passive devices which consume no electrical energy at all, or are active devices which consume very small amounts of electrical energy. The devices are reliable because they may have as few as only two parts, only one which is a moving part; and because they may handle fluids at very low pressures. The fluid handling devices include active piezoelectrically driven membrane pumps; and passive fluid flow regulators, on-off valves, flow switches and filters.

Abstract: A two-wafer microcapillary structure is fabricated by depositing boron nitride (BN) or silicon nitride (Si.sub.3 N.sub.4) on two separate silicon wafers (e.g., crystal-plane silicon with [100] or [110] crystal orientation). Photolithography is used with a photoresist to create exposed areas in the deposition for plasma etching. A slit entry through to the silicon is created along the path desired for the ultimate microcapillary. Acetone is used to remove the photoresist. An isotropic etch, e.g., such as HF/HNO.sub.3 /CH.sub.3 COOH, then erodes away the silicon through the trench opening in the deposition layer. A channel with a half-circular cross section is then formed in the silicon along the line of the trench in the deposition layer. Wet etching is then used to remove the deposition layer. The two silicon wafers are aligned and then bonded together face-to-face to complete the microcapillary.

Abstract: Capacitive microphones are fabricated using etch-release of sacrificial silicon by an isotropic dry etchant. The process allows the production of a microphone largely from CVD processes with flexibility in materials selection. The dry etch chemistry does not require freeze-drying after release. The etchant does not attack electrodes or metallized circuitry and so allows the placement of the electrodes between the backplate and diaphragm dielectric layers. Diffusion barrier layers between the sacrificial and electrode layers protect both materials from interdiffusion during device fabrication. The process is especially fitting for a microphone comprising silicon nitride dielectric layers with aluminum electrodes.

Abstract: A floating head slider having an air bearing surface is manufactured by forming a read/write element over the top surface of a rail forming substrate and over the sidewall of a groove formed into the rail forming substrate. A flattening film is formed over the read/write element to planarize the structure, and a slider base substrate is stacked over the flattening film. Parallel rails are formed on the bottom of the rail forming substrate by etching a flat recess into the bottom of the rail forming substrate, thereby forming the air bearing surface. A signal line is connected to the read/write element by filling a hole in the slider base substrate and the flattening film with a conductive material. The rail forming substrate and the slider base substrate are cut along the side surface of the groove to expose the portion of the read/write element formed on the side surface of the groove, and the rail forming surface is polished to form a front gap portion of the read/write element.

Abstract: A light emitting device (10) incorporates a layer (12) of porous silicon of low dimensionality surmounted by a discontinuous layer of silver in the form of discrete islands (20). A digitated electrode (13) is connected to the islands (20). The islands (20) have diameters in the range 5 nm to 20 nm and spacings in the range 10 nm to 50 nm, and they form a Schottky diode structure on the silicon (12). Under electrical bias, the diode structure conducts and light is generated. The device (10) is produced by vacuum deposition of silver onto a silicon wafer at a temperature which provides for the silver to separate into individual balls (20). The wafer is then anodized to produce a porous layer incorporating columns of silicon and silicon dioxide surmounted by respective silver islands (20). Each silver island (20) protects the underlying silicon (21) from the anodizing medium, and subsequently provides an electrical contact to the silicon.

Abstract: A material deposition head having lithographically defined ejector units. Beneficially, each ejector unit includes a plurality of lithographically defined droplet ejectors. Furthermore, methods of fabricating such lithographically defined material deposition heads are also described.

Abstract: A porous silicon Light Emitting Diodes (LEDs) device and method for fabricating LEDs with supporting circuits on a silicon chip or wafer for a Full Width Array in which a switch diode structure is used to form the porous silicon LED element and later drives the LED after the LED is fabricated. The LED is formed by defining an area in the switch diode for placing an LED element. Epi silicon is deposited in the defined area; and the epi silicon is electrochemical etched to produce porous silicon. This procedure creates column-like Si structures of nanometer dimension which can efficiently emit visible to infrared light at room temperature. Next, the porous silicon LED chip can be cut and butted without excessive damage. In this way, the chips bearing both LEDs and drive circuitry are made of silicon and can be cut and accurately butted by known techniques to form a low cost, high resolution Full Width LED array.

Abstract: An apparatus for extruding a wide variety of plural-component and mixed monocomponent fiber configurations in a spin pack which utilizes one or more disposable distributor plates in which distribution flow paths are formed on one or both sides to distribute the polymer components to appropriate spinneret inlet hole locations. The etching process, itself inexpensive as compared to drilling, milling, reaming, etc., permits very thin metal plates to be employed, rendering the fabrication expense for the plates small, relative to the remainder of the spin pack, as to justify discarding or disposing of the plates rather than periodically cleaning them. The etching process also permits the etched distribution paths to be small and densely packed, whereby the spinneret orifices can be more densely packed in the spinneret and staggered as between rows and columns so as to increase the fiber yield per given spinneret surface area.

Abstract: A nozzle assembly for use in atomizing and generating sprays from a fluid. The nozzle assembly includes two members joined together. In one of the two members are formed one or more nozzle outlets, one or more fluid inlets, and a plurality of channels that form filter passageways. The nozzle outlets discharge fluid jets that impinge on one another to thereby atomize the fluid. Alternatively, an impact element or a vortex-generating structure can be used in the nozzle outlet to atomize the fluid. Methods are also provided for producing the nozzle assembly by forming the inlets, outlets, and/or channels through electrical or chemical etching or other processes that selectively remove material from at least one face of a nozzle assembly member.

Abstract: A method for manufacturing a collimator comprising the steps of patterning a plurality of thin metal strips into a plurality of basic plates, and forming grooves or ridges on front and back surfaces of each basic plates. Thereafter, the thin strips are folded, mated, and welded together to form pillar cells within the collimator.

Abstract: Manufacture of a microchannel plate may be improved using photoelectrochemical etching and thin film activation such as CVD and nitriding and oxidizing wall surface portions of pores formed in the substrate. The pore pattern may be changed by oxidizing and etching the substrate prior to activation.

Abstract: An etching process is disclosed which is suited for manufacturing color selecting mechanisms in wide scope of specifications without need of complicated process of manufacture.The etching process comprises the steps of (a) forming an etching resist layer (20) on the front surface (10A) of a work (10) and also forming a protective layer (12) on the back surface (10B), (b) patterning the etching resist layer (12) to form a first opening (22) and a second opening (24) smaller than and near the first opening, and (c) etching the work to form a slit zone (32) under the first opening (22) and a recess (34) under the second opening (24) while removing at least a portion (10C) of the work spacing apart the slit zone (32) and the recess (34), thereby forming an electron beam passage slit (30) having a greater opening area defined on the side of the front surface (10A) by the slit zone (32) and the recess (34). (See FIG.

Abstract: A semiconductor substrate has a plurality of chip portions and chip separating portions for partitioning the plurality of chip portions into each other. The plurality of chip portions and the separating portions are etched on one side of the semiconductor substrate so that each of the plurality of chip portions is provided with stencil patterns. Furthermore, the plurality of chip portions and chip separating portions are etched on the other side of the semiconductor substrate so that the stencil patterns are exposed and the plurality of chip portions are capable of being substantially separated from each other.

Abstract: A process of forming an aperture in a metallic sheet including the steps of:a) defining at least one feature in a sheet of metallic material;b) laser drilling the at least one feature but not entirely removing it from the metallic sheet, the at least one feature being partially filled by metallic material which has melted and resolidified; and thenc) chemically etching the metallic sheet and the melted and resolidified metallic material wherein the etchant attacks and at least partially dissolves the melted and resolidified metallic material, weakening the bond of the melted and resolidified metallic material to the metallic sheet.

Abstract: A method is provided for preparation of a composite including steps of providing a preform and a liquid infiltrant alloy including at least two elements and having a liquid infiltrant alloy composition which is selected so that the liquid infiltrant alloy spontaneously infiltrates the preform and contacting the liquid infiltrant alloy with the preform so that a chemical reaction occurs to form a composite by reactive infiltration, as are composites produced according to the method of the invention.

Abstract: The invention is a field-emission element having a cathode with a sharp apex and a gate with an aperture diameter less than 1 .mu.m that is fabricated by covering a silicon substrate with a silicon oxide layer, forming an etching mask of 1.0 .mu.m diameter from a silicon oxide layer by photolithography, wet-etching the etching mask to form a minute etching mask of less diameter, dry etching the substrate to form a cylindrical solid structure, followed by anisotropic etching to form a couple of minute conical-shaped structures facing each other and connected by their respective tops, vacuum evaporating around the minute structures an insulating layer and thereon a conducting layer for use as a gate electrode, and etching the minute structure to lift off the upper part of the minute conical shaped structures.

Abstract: A filament reinforced perforate composite sheet is manufactured by forming a filament assembly which includes reinforcing filament structures and passage forming filament structures and in which the passage forming filament structures extend from the front face to the rear face of the assembly, applying a matrix material to the assembly to form a composite sheet in which the passage forming filament structures extend from the front face to the rear face of the sheet and removing the passage forming filament structures or a part or parts thereof to produce a multiplicity of passages extending through the composite sheet.

Abstract: A method for manufacturing a shadow mask for use in a cathode ray tube includes providing a thin metal web having a first and second major surfaces. Photosensitive layers are formed on the first and second major surfaces. The first photosensitive layer is exposed to a first patterned light and the second photosensitive layer is exposed to a second patterned light. The exposure is continued until respective accumulated exposure of the photosensitive layers reaches a predetermined value. Next, a first protective film is applied to the second photosensitive layer to prevent etching of the second surface. The first surface is then etched to form a first cavity. The first cavity has a depth that is less than a distance from the first surface to the second surface. A second protective film is applied to the first surface to prevent additional etching of the first surface. Then the first protective film is removed and the second surface is etched to form a second cavity.

Abstract: A method of producing a high-purity, ultra-fine powder of a first metal, particularly silver, by forming an alloy of the first metal with a second metal, such as aluminum subjecting the alloy to a leaching agent effective to leach out the second metal, leaving a porous first metal agglomerate; mixing the porous first metal agglomerate with a fresh batch of leaching agent; disintegrating the agglomerate and applying ultrasonic oscillations to the mixture to enhance the penetration of the leaching agent into the pores of the agglomerate; removing the leaching agent, leaving the first metal; and washing and drying the first metal.