Metal Etching

About Metal Etching and Metal Etching Services Including: Acid Etching, Chemical Etching, Chemical Milling, Metal Engravers, Metal Engraving, Photo Engraving, Photo Etching & Stainless Steel Etching.

Metal etching, also known as "milling" or "machining," is the production of a depressed design on a metal plate. These grooves and patterns are used for a variety of purposes, from jewelry and gunsmith decoration to fabricating industrial stencils and circuit boards. For decorative etching, the surfaces are sometimes smoked so that the lines will be more visible. Etching is used to create metal industrial parts that require many small grooves or holes, or as a decorative finish on many metals. Metal etching can also help a metal to meet weight demands by dissolving an appropriate layer of the surface. Some metal engravers still use fine-tipped steel tools to etch metal by hand, while other high-production metal engraving techniques use acid etching, chemical etching, photo engraving, photo etching and stainless steel etching, methods which are chemically complex but far faster and more accurate than hand engraving.

Mechanical milling employs the use of a lathe or milling machine with rotogravure tips. Hobbyists and artists often engrave by hand with steel pointed tools. Chemical milling, or acid etching, uses a process of masking and corrosive chemical exposure to create grooves, images, and pocked surfaces, and photo etching, similar to chemical milling, uses photographic technology to create a light-developed pattern which is then etched chemically. Electro discharge machining, or EDM, is similar to both chemical and photo etching, except that instead of exposing metal etching surfaces to chemicals, they are exposed to streams of corrosive electromagnetic discharge. Laser etching is another type of engraving which is used to create very fine, clean lines in metal surfaces. After the metal has been etched, pock marks or imperfections may be smoothed or burnished away.

A broad range of metals can be used during the acid-based processes, including stainless steel, copper, brass, nickel and silver alloys. Other metals can be etched using gas or electric-based processes. If a metal piece is in need of fine grooves, laser etching is often used. Abrasive etching with high-compression air is another option. In this process, abrasives such as aluminum oxide or sand are sometimes blasted in place of laser technology when isolated areas are being worked. Photochemical etching, which is the most common etching method, is a low-cost process that provides high quality, fast turnaround and precision accuracy unavailable in other etching processes. This process also allows flexibility in the design of parts, as changes can be made quickly, simply and cost-effectively.

Metals are engraved by many industries for a variety of purposes. The medical field uses stents, cathodes and implants. Brake rotors and fuel cell plates are made for the automotive industry. The sign and plaque industry heavily relies on the use of etching services, and jewelry use metal etching to create fine lines for intricate details. Photochemical etching produces business cards, logo name plates, panel covers and promotional items for the commercial sector. Metal etching services also create longer lasting stencils for the woodworking and art fields, printed circuit boards for the aerospace and electronics industries, and engraved or reduced missile skin panels and jet frames for defense. Book publishers, illustrators and artists use metal engraved plates to produce multiple pressed images, although engraved illustrations are beginning to fall out of use. Many hobbyists and artists continue to use hand engraving, which yields a less precise but more organic result.

Metal Etching and Metal Etching Services Image Provided by Photo Chem Etch Corporation	Metal Etching and Metal Etching Services Image Provided by Advanced Metal Etching, Inc.

Metal Etching Types

• Abrasive etching is the process of using controlled, high-pressure compressed air to direct an abrasive, such as sand or aluminum oxide, at the surface of a material to create the etched effect.
  
• Acid etching uses acid to engrave the surface of sheet metal.
• Chemical etching uses acids, bases, and other chemicals to etch into the surface of metal.
• Dry etching refers to any etching process that does not employ the use of chemicals.
  
• Electroetching is an etching process that involves the use of chemicals, along with the employment of direct electric current.
• Laser etching employs the use of a laser for the removal of a specified pattern on a metal piece. Laser etching is often used in the jewelry industry.
  
• Metal engravers are metal tools used to carve designs into metal surfaces.
• Metal engraving is the process by which metal tools are employed to carve a design into metal.
• Photo engraving uses photosensitive material that is resistant to acid and applies it to the surface of a metal sheet. Acid is then applied, creating an image by burning through the areas where the acid-resistant material is missing.
• Photo etching, the most common metal etching process and otherwise referred to as "metal chemical etching," "chemical milling," "photochemical etching," "chemical etching" or "photochemical machining," is the process in which a desired image is etched on the surface of the metal part via a photosensitive template. The piece is then exposed to an appropriate acid (or etchant) that removes a layer of metal in areas left unprotected by the template, after which the piece is cleaned and the photoresist template removed.
  
• Reactive Ion Etching (REI), also known as "plasma etching," is a dry etching technique. REI involves the use of electrical circuits and high-energy gas made up of ionized particles containing fluorine or chlorine.
• Sputter etching is a type of REI etching but without the employment of ions.
• Stainless steel etching is used to create stainless steel industrial parts that require many small grooves or holes, or a decorative finish.
• Vapor phase etching is a dry etch technique that uses reactive gases to achieve the desired etching pattern.

Metal Etching Terms

Acid - A substance that, when dissolved in water, forms a solution with a pH of less than seven.
 
Bend Lines - Lines that are partially etched into the surface of the metal, which aid in the bending of the part in a subsequent operation.
 
Burn-In - The process of heating a developed photoresist image until the resist coating becomes chemically resistant.
 
Chemical Blanking - A term originally used to refer to the process of photo chemical machining (PCM).
 
Chlorine Regeneration - A process in which ferric chloride acid is regenerated to maintain high quality acid for the etching process.
 
Coating - The dipping, rolling, spraying, laminating, spinning, printing or flowing of the substrate surface layer of a photoresist material in order to cover it with a resist.
 
Contact Printing - A photographic process in which an image is transferred from one substrate to another.
 
Conversion Coating - The subjection of a substrate surface to high temperatures or the pickling process in order to improve photoresistant adhesion.
 
Dry Film Resist - Photoresist in the form of rolled sheet laminate.
 
Etch Band Design - Designing artwork for parts to be photochemically machined so that all shapes are outlined with a controlled line to be etched.
 
Etchant - An acid used to dissolve a layer of metal to form the component.
 
Fret - A series of etched parts that are tagged into a frame. Blanks usually have several frets etched into them.
 
Halogen - Non-metallic elements fluorine, chlorine, bromine and iodine.
 
Intaglio - An image etched/sunk into the surface of a piece.
 
Ion - An electrically charged atom or group of atoms, the electrical charge of which results from a neutral atom or group of atoms losing or gaining one or more electrons.
 
Liquid Resist - A photoresist applied to the substrate by dipping, roller coating or spraying.
 
Photodiode - A device that receives optical power and changes it into an electrical signal.
 
Photoresist - A material that, when applied to any of a variety of substances, becomes sensitive to portions of the electromagnetic spectrum and, when properly exposed and developed, masks a portion of the material.
 
Spectral Sensitivity - The rate of response of a photographic material to a particular range of the electromagnetic spectrum.
 
Substrate - A structure that underlies and supports or forms base material on which coatings are applied.
 
Ultraviolet (UV) - Invisible electromagnetic radiation.