Parylene Coating

Glossary of Terms Used For - Parylene Conformal Coating

Glossary of Terms Used For

Acid:  An acid (often represented by the generic formula HA [H+A−]) is traditionally considered any chemical compound that, when dissolved in water, gives a solution with a hydrogen ion activity greater than in pure water, i.e. a pH less than 7.0. That approximates the modern definition of Johannes Nicolaus Bronsted and Martin Lowry, who independently defined an acid as a compound which donates a hydrogen ion (H+) to another compound (called a base). Common examples include acetic acid (in vinegar) and sulfuric acid (used in car batteries). Acid/base systems are different from redox reactions in that there is no change in oxidation state. Acrylic may refer to: chemical compounds that contain the acryl group derived from acrylic acid.

Acrylic: Poly (methylmethacrylate) (PMMA) poly (methyl 2-methylpropenoate) is a thermoplastic and transparent plastic. Chemically, it is the synthetic polymer of methyl methacrylate. It is sold by the trade names Plexiglas, Vitroflex, Limacryl, R-Cast, Per-Clax, Perspex, Plazcryl, Acrylex, Acrylite, Acrylplast, Altuglas, Polycast, Oroglass, Optix and Lucite and is commonly called acrylic glass, simply acrylic, perspex or plexiglas. Acrylic, or acrylic fiber, can also refer to polymers or copolymers containing polyacrylonitrile. The material was developed in 1928 in various laboratories and was brought to market in 1933 by Rohm and Haas Company. PMMA is often used as an alternative to glass, and in competition with polycarbonate (PC). It is often preferred because of its moderate properties, easy handling and processing, and low cost, but behaves in a brittle manner when loaded, especially under an impact force. To produce 1 kg of PMMA, about 2 kg of petroleum is needed. PMMA ignites at 460°C and burns completely to form only carbon dioxide and water.

Alkaline: In chemistry, an alkal is a basic, ionic salt of an alkali metal or alkaline earth metal element. Alkalis are best known for being bases that dissolve in water. Bases are compounds with a pH greater than 7. The adjective alkaline is commonly used in English as a synonym for base, especially for soluble bases. This broad use of the term is likely to have come about because alkalis were the first bases known to obey the Arrhenius definition of a base and are still among the more common bases. Since Bronsted-Lowry acid-base theory, the term alkali in chemistry is normally restricted to those salts containing alkali and alkaline earth metal elements.

Catheter: In medicine a catheter is a tube that can be inserted into a body cavity, duct or vessel. Catheters thereby allow drainage or injection of fluids or access by surgical instruments. The process of inserting a catheter is catheterization. In most uses a catheter is a thin, flexible tube: a “soft” catheter; in some uses, it is a larger, solid tube: a “hard” catheter.

Chamber: The entire Parylene process is generally carried out in a closed system under constant negative pressure. Such closed system may incorporate separate chambers for the vaporization, pyrolysis, and deposition steps of the process, with such chambers being connected by way of appropriate plumbing or tubular connections.

Conformal Coating: Conformal coating material is applied to a surface to act as protection against moisture, dust, chemicals, and temperature extremes. This type of coating “conforms” to the applied surface with an exact thickness of film 3 microns thick.

Dimer: A dimer is a chemical or biological entity consisting of two subunits called monomers, which are held together by either intramolecular forces (covalent bonds) or weaker intermolecular forces.

Elastomer Elastomeric: An Elastomer is a polymer with the property of elasticity. The term, which is derived from elastic polymer, is often used interchangeably with the term rubber, and is preferred when referring to vulcanisates. Each of the monomers which link to form the polymer is usually made of carbon, hydrogen, oxygen and/or silicon. Elastomers are amorphous polymers existing above their glass transition temperature, so that considerable segmental motion is possible. At ambient temperatures rubbers are thus relatively soft (E~3MPa) and deformable. Their primary uses are for seals, adhesives and molded flexible parts.

Environment: The biophysical environment is the symbiosis between the physical environment and the biological life forms within the environment, and include all variables that comprise the Earth’s biosphere. The biophysical environment can be divided into two categories: the natural environment and the built environment, with some overlap between the two. Following the industrial revolution, the built environment has become an increasingly significant part of the Earth’s environment.

Epoxy: In chemistry, epoxy or polyepoxide is a thermosetting epoxide polymer that cures (polymerizes and crosslinks) when mixed with a catalyzing agent or hardener. Most common epoxy resins are produced from a reaction between epichlorohydrin and bisphenol-A. The first commercial attempts to prepare resins from epichlorohydrin were made in 1927 in the United States. Credit for the first synthesis of bisphenol-A-based epoxy resins is shared by Dr. Pierre Castan of Switzerland and Dr. S.O. Greenlee of the United States in 1936. Dr. Castan’s work was licensed by Ciba, Ltd. of Switzerland, which went on to become one of the three major epoxy resin producers worldwide. Ciba’s epoxy business was spun off and later sold in the late 1990s and is now the advanced materials business unit of Huntsman Corporation of the United States. Dr. Greenlee’s work was for the firm of Devoe-Reynolds of the United States. Devoe-Reynolds, which was active in the early days of the epoxy resin industry, was sold to Shell Chemical (now Hexion, formerly Resolution Polymers and others).

Flight: Flight is the process by which an object moves either through the air, or movement beyond earth’s atmosphere (as in the case of spaceflight), by aerodynamically generating lift, propulsive thrust or aerostatically using buoyancy, or by simple ballistic movement.

Friction: Friction is the force resisting the relative lateral (tangential) motion of solid surfaces, fluid layers, or material elements in contact. It is usually subdivided into several varieties: Dry friction resists relative lateral motion of two solid surfaces in contact. Dry friction is also subdivided into static friction between non-moving surfaces, and kinetic friction (sometimes called sliding friction or dynamic friction) between moving surfaces. Lubricated friction [1] or fluid friction [2] [3] resists relative lateral motion of two solid surfaces separated by a layer of gas or liquid. Fluid friction is also used to describe the friction between layers within a fluid that are moving relative to each other. [4][5] Skin friction is a component of drag, the force resisting the motion of a solid body through a fluid. Internal friction is the force resisting motion between the elements making up a solid material while it undergoes deformation.

Green: Chemicals normally associated with being environmentally friendly by being biodegradable.

Hydrochloric: Hydrochloric acid is the solution of hydrogen chloride (HCl) in water. It is a highly corrosive, strong mineral acid and has major industrial uses. It is found naturally in gastric acid. Historically called muriatic acid or spirits of salt, hydrochloric acid was produced from vitriol and common salt. The alchemist Jabir ibn Hayyan first formally described it in the eighth century. During the middle Ages, it was used by alchemists in the quest for the philosopher’s stone, and later by European scientists including Glauber, Priestley, and Davy in their scientific research. With major production starting in the Industrial Revolution, hydrochloric acid is used in the chemical industry as a chemical reagent in the large-scale production of vinyl chloride for PVC plastic, and MDI/TDI for polyurethane. It has numerous smaller-scale applications, including household cleaning, production of gelatin and other food additives, descaling, and leather processing. About 20 million metric tons of hydrochloric acid are produced annually.

Lubricity: Lubricity is the measure of the reduction in friction of a lubricant. The study of lubrication and mechanism wear is called tribology.

Micron:  A micron is equal to one millionth of a meter, or about a tenth of the size of a droplet of mist or fog. It is particulate smaller than the naked eye can see. A micron is 1/25,000th of an inch. A human hair is about 150 micros; the smallest thing that can be seen with the naked eye is about 10 microns. It is the largest particles, above 5.0 microns, that cause equipment problems and are what most filters are able to catch. However, 98% of the particles in the air are smaller than 1.0 micron. These “sub-micron” particles are not caught by most filters and get through our bodies’ natural defenses when inhaled. In technical terms, 1000 microns is equal to 1 mm. Human hair is 60 to 80 microns and the smallest visible object is about 40 microns across. 1 micron = 0.03937007874 mil

MIL: A United States Defense Standard, often called a military standard, “MIL-STD”, “MIL-SPEC”, or (informally) “MilSpecs”, is used to help achieve standardization objectives by the U.S. Department of Defense. Standardization is beneficial in achieving interoperability, ensuring products meet certain requirements, commonality, reliability, and total cost of ownership, compatibility with logistics systems, and similar defense-related objectives [1] .Defense Standards are also used by other non-Defense government organizations, technical organizations, and industry. This article discusses definitions, history, and usage of Defense Standards. Related documents, such as Defense Handbooks and Defense Specifications are also addressed.
Moisture: Moisture generally refers to the presence of water, often in trace amounts. The moisture content is often an important aspect of various foodstuffs including cheese and many dried goods such as tea where excess moisture can promote bacterial growth, decay, molding, or rotting over time. Excessive moisture is usually undesirable and can also cause rot in wood or other organic material, corrosion in metals, and electrical short circuits. Many home and business owners go to great pains to prevent these effects. Many products are sold to prevent this. Some foodstuffs and other packaged products come with desiccators, often made of silicon oxide, to absorb moisture. In skin, leather, and wood, moisture can also refer to natural oils. Moisture is also sometimes used to refer to the liquid form of solvents other than water, especially when present in a solid. Moisture is also used to refer to any type of precipitation.

Monomer: Monomer is a small molecule that may become chemically bonded to other monomers to form a polymer.
Paraxylylene: The present invention provides a new class of precursors for forming an improved diamond-like carbon coating on a work piece. The precursors of the present invention are paraxylylenes, preferably dimers of paraxylylene, which are solid at room temperature and which will vaporize, pyrolize to substantially monomeric form, condense onto a work piece, and spontaneously polymerize to form a “parylene” film which is free of precursor droplets and absorbed water. Upon bombardment with an ion beam, the parylene film is converted into a uniform, pinhole-free DLC coating.

Pitch: A measure of distance between leads from an integrated circuit

Plastic: Plastic is the general common term for a wide range of synthetic or semi-synthetic organic solid materials suitable for the manufacture of industrial products. Plastics are typically polymers of high molecular weight, and may contain other substances to improve performance and/or reduce costs. The word derives from the Greek (plastikos), “fit for molding”, and from (plastos) molded [1] [2]. It refers to their malleability, or plasticity during manufacture that allows them to be cast, pressed, or extruded into an enormous variety of shapes — such as films, fibers, plates, tubes, bottles, boxes, and much more. The common word “plastic” should not be confused with the technical adjective “plastic”, which is applied to any material which undergoes a permanent change of shape (a “plastic deformation”) when strained beyond a certain point. Aluminum, for instance, is “plastic” in this sense, but not “a plastic” in the common sense; while some plastics, in their finished forms, will break before deforming — and therefore are not “plastic” in the technical sense.

Polymer: A polymer is a large molecule (macromolecule) composed of repeating structural units typically connected by covalent chemical bonds. While polymer in popular usage suggests plastic, the term actually refers to a large class of natural and synthetic materials with a variety of properties and purposes. Polypropylene: IUPAC name [show] Poly (propane-1, 2-diyl) except where noted otherwise, data are given for materials in their standard state at 25 °C, 100 kPa). Well-known examples of polymers include plastics and proteins. A simple example is polypropylene, whose repeating unit structure is shown at the right. However, polymers are not just limited to having predominantly carbon backbones, elements such as silicon form familiar materials such as silicones, examples being silly putty and waterproof plumbing sealant. The backbone of DNA is in fact based on a phosphodiester bond. Natural polymer materials such as shellac and amber have been in use for centuries. Biopolymers such as proteins and nucleic acids play crucial roles in biological processes. A variety of other natural polymers exist, such as cellulose, which is the main constituent of wood and paper. The list of synthetic polymers includes Bakelite, neoprene, nylon, PVC, polystyrene, polyacrylonitrile, PVB, silicone, and many more. Polymers are studied in the fields of polymer chemistry, polymer physics, and polymer science.

Potting: In electronics, potting is a process of filling a complete electronic assembly with a solid compound for resistance to shock and vibration, and for exclusion of moisture and corrosive agents. Thermosetting plastics are often used. Most circuit board assembly houses coat assemblies with a layer of transparent conformal coating rather than potting. Conformal coating gives most of the benefits of potting, and is lighter and easier to inspect, test, and repair. When potting a circuit board that uses surface-mount technology, Potting Solutions recommends using low TG potting compounds such as polyurethane or silicone, because high Tg potting compounds may break solder bonds as they harden and shrink at low temperatures.

Rectifier: A rectifier is an electrical device that converts alternating current (AC) to direct current (DC), a process known as rectification. Rectifiers have many uses including as components of power supplies and as detectors of radio signals. Rectifiers may be made of solid state diodes, vacuum tube diodes, mercury arc valves, and other components. A device which performs the opposite function (converting DC to AC) is known as an inverter. When only one diode is used to rectify AC (by blocking the negative or positive portion of the waveform), the difference between the term diode and the term rectifier is merely one of usage, i.e., the term rectifier describes a diode that is being used to convert AC to DC. Almost all rectifiers comprise a number of diodes in a specific arrangement for more efficiently converting AC to DC than is possible with only one diode. Before the development of silicon semiconductor rectifiers, vacuum tube diodes and copper (I) oxide or selenium rectifier stacks were used. Early radio receivers, called crystal radios, used a “cat’s whisker” of fine wire pressing on a crystal of galena (lead sulfide) to serve as a point-contact rectifier or “crystal detector”. In gas heating systems flame rectification can be used to detect a flame. Two metal electrodes in the outer layer of the flame provide a current path and rectification of an applied alternating voltage, but only while the flame is present.

Refraction: Index of Refraction: The refractive index (or index of refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium. For example, typical soda-lime glass has a refractive index of 1.5, which means that in glass, light travels at 1 / 1.5 = 0.67 times the speed of light in a vacuum. Two common properties of glass and other transparent materials are directly related to their refractive index. First, light rays change direction when they cross the interface from air to the material, an effect that is used in lenses. Second, light reflects partially from surfaces that have a refractive index different from that of their surroundings.

Resistance: Electrical resistance, a measure of the degree to which an object opposes an electric current through it.

Silicone: Silicones are largely inert compounds with a wide variety of forms and uses. Typically heat-resistant, nonstick, and rubberlike, they are frequently used in cookware, medical applications, sealants, lubricants, and insulation. Silicones are polymers that include silicon together with carbon, hydrogen, oxygen, and sometimes other chemical elements. One of the most common uses is holding glass together (e.g., in aquariums).

SMT: Surface-mount technology (SMT) is a method for constructing electronic circuits in which the components (SMC, or Surface Mounted Components) are mounted directly onto the surface of printed circuit boards (PCBs). Electronic devices so made are called surface-mount devices or SMDs. In the industry it has largely replaced the through-hole technology construction method of fitting components with wire leads into holes in the circuit board. An SMT component is usually smaller than its through-hole counterpart because it has either smaller leads or no leads at all. It may have short pins or leads of various styles, flat contacts, and a matrix of solder balls (BGAs), or terminations on the body of the component.

Spec: In engineering, manufacturing, and business, it is vital for suppliers, purchasers, and users of materials, products, or services to understand and agree upon all requirements. A specification is a type of a standard which is often referenced by a contract or procurement document. It provides the necessary details about the specific requirements. Specifications may be written by government agencies, standards organizations (ASTM, ISO, CEN, etc), trade associations, corporations, and others. A product specification does not necessarily prove the product to be correct. Just because an item is stamped with a specification number does not, by itself, indicate that the item is fit for any particular use. The people who use the item (engineers, trade unions, etc) or specify the item (building codes, government, industry, etc) have the responsibility to consider the available specifications, specify the correct one, enforce compliance, and use the item correctly. Validation of suitability is necessary. An example of a US Federal specification is FIPS-PUB 159, Detail Specification for 62.5-μm Core diameter/125-μm Cladding Diameter Class IA Multimode Optical Fibers. (Source: from Federal Standard 1037C and from MIL-STD-188)

Urethane: Are a group of organic compounds sharing a common functional group with the general structure – NH (CO) O -. Carbonates are esters of carbamic acid, Nh3COOH, an unstable compound. Since carbamic acid contains a nitrogen attached to a carboxyl group, it is also an amide. Therefore, carbamate esters may have alkyl or aryl groups substituted on the nitrogen, or the amide function. For example, ethyl carbamate (trivial name “urethane”), is unsubstituted, whereas ethyl N–methylcarbamate has a methyl group attached to the nitrogen (see methyl isocyanate for formation of N-methylcarbamates).

Vacuum: Vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. [1] The word comes from the Latin term for “empty,” but in reality, no volume of space can ever be perfectly empty. A perfect vacuum with a gaseous pressure of absolute zero is a philosophical concept that is never observed in practice. Physicists often discuss ideal test results that would occur in a perfect vacuum, which they simply call “vacuum” or “free space” in this context, and use the term partial vacuum to refer to real vacuum. The Latin term in vacuo is also used to describe an object as being in what would otherwise be a vacuum. The quality of a vacuum refers to how closely it approaches a perfect vacuum. The residual gas pressure is the primary indicator of quality, and is most commonly measured in units called torr, even in metric contexts. Lower pressures indicate higher quality, although other variables must also be taken into account. Quantum theory sets limits for the best possible quality of vacuum, predicting that no volume of space can be perfectly empty. Outer space is a natural high quality vacuum, mostly of much higher quality than can be created artificially with current technology. Low quality artificial vacuums have been used for suction for many years.

XY: Parylene is the trade name for a variety of polyxylylene polymers marketed by several providers, including Kisco Conformal Coating, LLC [1], Para Tech Coating, Inc. [2], Specialty Coating Systems, Inc. [3], Parylene Coating Services and others. Parylene N is a polymer manufactured from di-p-xylylene, a dimer synthesized from p-xylylene. Di-p-xylylene, more properly known as [2.2] paracyclophane, is made from p-xylylene in several steps involving bromination, amination and elimination.

ZEROVOC: Serova is a water-based, solvent free, super hydrophobic, self-reactive siliconate HYBRID protective water sealer. I is formulated to deeply penetrate and chemically react within the treated material on a molecular level. Because of the unique cross-linking and symbiotic relationship of the components contained in this compound, this chemical reaction forms a hard, tight, insoluble, microscopic crystalline structure within the treated material creating an impermeable water barrier. The unique crystalline structure actually fuses into the material, encapsulating surface and interior particles while filling up capillaries and macro and micro spaces within the material. Once the protective water sealer is fully dried the effect is irreversible and the water resistance of the treated material is permanent. If combines the latest advances in the water sealer technology with tried and proven silicate technology creating a protective water sealer that is unmatched and unsurpassed at withstanding the elements. It is a “one-of-a-kind” protective water sealer and is the result of years of research based upon advanced reactive siliconate technology. It is in a class by itself and differs greatly from other water repellents and water sealers on the market. Zerovoc was developed for any application where long-term durability and extreme water protection are required.

Parylene Deposition Process