Invented by Andrew T. Hunt, Girish N. Deshpande, Tzyy-Jiuan Jan Hwang, Nii Sowa Laye, Miodrag Oljaca, Subramaniam Shanmugham, Shara S. Shoup, Trifon Tomov, William J. Dalzell, Jr., Aimee Poda, Michelle Hendrick, Microcoating Technologies Inc
The Microcoating Technologies Inc invention works as followsThe vapors produced by the combustion process are diverted away from the flame direction by differential atmospheric pressure. This can be achieved by blowers or vacuums that provide positive pressure. This allows for lower surface temperatures on substrates that are coated with flame produced vapors, and coating interior surfaces.
Background for Chemical Vapour Deposition Methods for Making Powders and Coatings, and Coatings Made Using These Methods
The chemical vapor deposition process has been very successful in allowing scientists and engineers to coat delicate substrates, and form coatings with improved performance for specific applications. The success of CCVD methods has increased engineers’ interest and desire to develop new processes and techniques that will allow them to treat and coat other substrates, and create coatings for new applications.
The combustion chemical vapor deposit (CCVD), described in U.S. Pat. Nos. Nos. These patents are hereby included by reference and disclose methods and apparatuses for CCVD films and coatings. A reagent and carrier medium are combined to form a mixture of reagents. The mixture can be ignited into a flame, or fed through a plasma torch. The flame or torch heats and vaporizes reagents, as well as heating the substrate. The CCVD technique has enabled new applications, and new coatings with improved properties and novel compositions.
U.S. Pat. No. No. Snyder et. al. received a patent on June 4, 1991, which discloses a method for fabricating nickel-oxide coatings over superconductors. The superconducting cable may be made of niobium and tin. Purified carbonyl, in contact with non-reacted Niobium and Tin on the surface of wires, is coated with nickel sub-oxide. Nickel-oxide is used to create an outer layer of insulation on several different superconductors. The nickel-oxide layer thickness is between 1.5 and 20 microns. However, this technique might not produce a resistive enough layer at thicknesses less than 1.5 microns.
The U.S. Patent teaches “An insulated cable is taught” No. No. The wire is composed of a conductor, an anodic layer, and an oxide insulation layer. The conductor can be either pure aluminum or copper-clad wire. The anodic oxide layer is formed on the aluminum’s outer surface by dipping the wire in sulfuric acid, and then applying positive voltage. Sol-gel is used to deposit the oxide layer on top of the anodic film. The anodic film thickness is typically 10-20 microns, with the total oxide layer thickness being 20-40 microns. The oxide insulators described in this reference are strong and provide good insulation, but the thickness of the oxide coatings is much greater than what’s needed for some applications.
U.S. Pat. No. No. 5,468,557 was issued to Nishio and others on November 21, 1995. The drawing shows a ceramic-insulated electrical conductor cable. Also discussed is the method for making the wire. A copper or copper alloy conductor is surrounded by a stainless-steel layer. On the stainless steel, a chromium-oxide film is formed. An outer ceramic insulator layer is then formed on top of the chromium-oxide layer. The core of the stainless steel-clad copper wire is placed lengthwise in a stainless steel tube, then the wire is plastically worked to the desired size. The stainless steel contains enough chromium to form a chromium-oxide film on the surface when it is oxidized. On top of the chromium-oxide film, the outer ceramic insulator layer is vapor deposited. The chromium film has a thickness ranging from 10 nm up to one micron, but the insulating layer is 3-4 microns. The chromium layer is used to increase the adhesion of the stainless steel with the outer ceramic coating. The methods described in the reference produce oxide coatings several microns thin, but the reference does not describe how these oxide coatings can be used as an insulator.
Other materials, in addition to those described above, have been used to make insulators for electrical conductors. In U.S. Patent, a Japanese lacquer is used to coat a conductor. No. No. 5,767 450 was issued to Furuhata on June 16, 1998. Furuhata. The coated conductor can be used in small coils, such as the ones found in electric watches. The coatings in this reference may be thin (as low as 0.1 microns thick), but the materials that are used to deposit the Japanese lacquer tend to breakdown at higher temperatures. The production of these coatings also has an unfriendly environmental impact.
Another useful use of the deposition techniques described in the prior arts is the production of various coatings on products made from polymer.” Deposition techniques were used to create barrier layers in polymer-based packaging materials for food and beverages. These packaging materials must also be flexible (or rigid in some cases) and act as a barrier against gas transportation (oxygen or carbon dioxide). Aroma and flavor. These polymer containers may be somewhat protective but they are not impermeable because of their inherent amorphous areas and physical properties. These regions allow oxygen and water vapour to pass through, which can lead to the degradation of food products. Temperature and thickness of polymer packaging affect the rate of oxygen and moisture vapor transport. The thicker the packaging is, the higher the cost of manufacture. Barrier layers made of another material, such as silica, reduce the permeability and increase the scratch resistance of polymers that they are applied to. They also control the tribology or the surface finish of the packaging. Prior art methods for producing these barriers layers used vacuums, CVD or other complex and environmentally hazardous practices. The adhesion between the polymer and barrier layers has been low, creating a contamination risk as the material could flake off and mix with food or beverages.
U.S. Pat. No. No. 5,085,904, issued to Deak and others on February 4, 1992. Barrier materials for packaging are disclosed. Multi-layer structures are shown, including a resin base, a SiO vacuum deposition layer, a SiO2 vacuum deposition layer on top of the SiO, and an adherent outer layer. The resin substrate can be either a polyamide or polyester resin. All silicon layers disclosed are vacuum-deposited, and the methods for forming these coatings need vacuum equipment. They also have other disadvantages.
Patent No. US Pat. No. No. 5,916,685, issued on Jun. 29, 1999 to Frisk. Frisk. In one embodiment, a SiOx layer is deposited on a polymer. x can be between 1.5 and 2. SiOx can be deposited by a variety of methods, but plasma-enhanced vapor deposition is preferred. The polymer can be selected from polyamides or polyethyleneterephthalate copolymers and mixtures of these. The polymer is integrated with a clay mineral. These products, like other laminates of the past, are made using methods with inherent disadvantages. This includes contamination from poor adhesion or bonding.
None, either individually or in combination with the other references and patents cited above, can be seen as describing the instant invention, as claimed.
The present invention is directed at methods of coating and processing powder materials, including chemical-vapor deposition (CVD), in which the activating energy sources and/or active deposition gases produced by them are redirected or redistributed to control material properties, reduce the gas temperature, or increase the area coated with the deposition material. By directing deposition gases, vapor clusters, and particles in an opposite direction to the heat generated by the energy source it is also possible to control substrate temperatures so that deposition can occur without damaging substrate. A CVD energy source is a thermal, electromagnetic, flame or plasma. The energy source provides the necessary energy to cause the coating precursors react, and form the material that is used to coat the substrate. The energy source is directed towards the substrate to heat at the very least a portion so that the precursors can be activated and deposition takes place. The present invention, by redirecting activated materials in gasses, goes beyond conventional chemical evaporation. The precursors can reach the temperatures necessary to form the coating compositions while avoiding damaging the substrate. The redirected gases are also more thoroughly mixed and provide a uniform coating and heat distribution to the substrate. This is especially useful for the production of electrochemical or barrier coatings on polymers as well as protective and insulating coatings in metal foils and electromechanical coilings.
When used to redirect combustion sources in a CCVD, the present invention offers the same advantages as conventional CCVD over other thin film technologies (such CVD). CCVD has the advantage of being able to deposit thin films in an open atmosphere, without needing a furnace, vacuum or reaction chamber. The initial capitalization of the system can be reduced by up to 90% when compared with a vacuum-based technology. A combustion flame can provide the environment necessary for the deposition elemental constituents derived from solution, gas, or vapor sources. The precursors are usually dissolved in the same solvent that is also used as a combustible. The deposited material can be placed under atmospheric conditions, including temperature and pressure, in an exhaust hood or outdoors.
CCVD is a technology that uses solutions to deposit films. This allows for rapid and simple changes of dopants, and their stoichiometries. CCVD is a technique that uses soluble, inexpensive precursors. The Nanomiser? As described in copending U.S. Patent applications Ser. No. No. 08/691 853, filed on Aug. 2, 1996 (now U.S. Patent. No. Patent No. 5,997,956) and U.S. Ser. Nos. All three patents, Nos. As divisionals to U.S. Patent Application Ser. No. No. By reference, these patent applications are included. The precursor vapor pressures do not usually play a part in CCVD, because the dissolution provides the energy to create the necessary ionic components. The stoichiometry of the deposited film can be varied by adjusting the solution concentrations. The CCVD method allows for both the chemical composition and the physical structure of deposited films to be tailored according to the application requirements.
CCVD is not limited to a rigid, expensive reaction chamber with low pressure. The deposition flame or bank of fire can therefore be moved over the substrate in order to coat large and/or complicated surface areas. CCVD is not restricted to specialized environments. Therefore, materials can be continuously fed into the coating area, without interruption, and batch processing is possible. The user can also limit the deposition of a coating to specific areas by controlling the dwell times of the flames on the substrate. The CCVD process uses chemical precursors that are halogen free and have a reduced environmental impact.
The present invention provides all the advantages described above for conventional CCVD and also allows for a more even and uniform distribution of deposition gases. This allows CVD, CCVD and any other chemical deposition processes to be used on substrates which would otherwise be oxidized, cracked, or damaged by direct heat from hot gasses and the energy source. In one embodiment, a secondary jet of gasses containing liquids or solids are directed at the active deposition gases emerging from the energy sources to carry the coating constituents directly to the substrate. This is done without actually pointing the source of the precursor gas directly at the substrate. This secondary stream can be compressed air or oxygen, nitrogen or argon or a combination of these gasses. It may also contain liquids and/or solids that are a part of or the entire second precursor solution. The jet must be directed to the combustion source so that the constituents of the coating can reach the temperature required for coating formation. The combustion source creates its own material flow, so the jet combined with the combustion source will produce a flow of slightly cooler deposition gases that are directed to the desired portion of the substrate. This is called ‘aiming’. This?aiming? change.
When the material that is expelled from the redirect jet doesn’t require energy or it isn’t used to make powders or coats, then the jet can be directed above, below, or to the side. The result is a pressure difference that bends energized gases without cooling the energy source directly. It is usually not desirable to limit the temperature that can be reached within the energy source. The temperature of the flame can be maintained high enough for the precursor solution to form the coating, but the substrate temperature is reduced by adjusting the flow rate and velocity. The interaction between the air/gas and energy source (which is often a vector in itself, such as flame) causes a vigorous mixing of hot deposition gases, reducing the temperature and concentrations gradients and directing deposition materials towards the desired area of the substrate. The vapor pressure of the deposition materials is usually very low after reaction with the precursor. This results in a supersaturated vapour that quickly condenses. The secondary gas stream dilutes the deposition gases, which reduces the rate at which gas phase clusters grow, and accelerates active vapor clusters towards the substrate surface. This decreases cluster growth time. Many types of coatings require that the deposition species (sub-critical nucleus size clusters) remain vapor until they reach the substrate to allow for absorption and surface diffusion. Diffusion can be controlled by temperature. In certain cases (e.g. In some cases (e.g. The present invention uses a redirect source in order to reduce the rate of diffusion/reaction and maintain a lower substrate temperature. A CCVD flame is quickly cooled down using an air/gas spray to direct the coating components to the surface of substrate. The coating is deposited at lower temperatures. The film maintains the same quality of those deposited at higher temperatures, because the high-speed jet reduces the distance between the coating components and the substrate. The shorter travel distance, combined with the diluted vapor stream of deposition, prevents coating constituents from agglomerating or becoming coarser. The film formed by gas jet-assisted CCVD is dense and not powdery or granular, as can happen with low CCVD temperatures. A high-velocity jet can also help to break up the gas barrier layer, increasing the deposition rates and providing a uniform coating thickness for substrates with irregular shapes and rough surfaces.
A vacuum source is another way to redirect the energized gases. The gasses are accelerated in one direction, at an angle to the substrate. The vacuum source is placed in a way that the heat, flame or plasma of the energy source bends towards the substrate. The result, as with previous embodiments is a combustion or energy source hot enough to form an active species coating without directly heating the substrate. The use of a vacuum source has the additional benefit that no additional oxidizing material (such as oxygen or air) is added to the combustion. It is especially useful for materials that are sensitive when oxygen is present. In addition to the multiple vacuum or pressurized nozzle sources, it should be noted that multiple CCVD or energy/materials sources can be used to speed up deposition. CCVD does not require vacuum chambers. Therefore, multiple CCVD nozzles, jets, and vacuums can be easily adjusted in CCVD embodiments to achieve the desired deposition gas directions.
As previously stated, one of the uses of the deposition method of the present invention would be to form thin films of insulative oxide on conductors. These conductors are used as wires in electromagnetic components (such transformers, coils motors solenoids relays etc.). The conductors are wrapped in tightly packed stacks, or wound. The thickness of insulation used to isolate each layer from the adjacent layers has a significant impact on the device’s efficiency. The insulated section of the windings is not a conductor of electrical current and does not generate magnetic flux. The magnetic flux and field strength of an actuator of any size can be increased by reducing the thickness insulative coating. The reduction in the thickness of the coating has only a small effect on wires of relatively large diameter. The thickness of the insulation has a significant impact on device efficiency when devices use small diameter conductors. The need for miniature electromagnetic devices with higher efficiency continues to grow as electronic components become smaller. “The thin film insulative films of the present invention offer extremely thin insulation while providing electrical resistance between adjacent components and windings.
Oxide insulators can also be used in cable applications. The same space can be used to carry higher currents with increased conductor cross-sections relative to the cable’s overall cross section. A thin oxide coating can reduce the thickness of the insulator while increasing the breakdown voltage. The oxide coating can be protected from abrasion by an outer polymer coating. This will also add additional dielectric material.Click here to view the patent on Google Patents.