In industry, etching (sometimes called chemical milling or wet etching) is the process of using acids, bases or other chemicals to dissolve away unwanted materials such as metals, semiconductor materials or glass. It has applications in the printed circuit board and semiconductor fabrication industries. A Miller is a person who operates a mill for grinding material and usually refers to one who grinds a cereal crop to make flour. ... Acidity redirects here. ... A base in chemistry is a chemical substance which has a free pair of electrons to bind a hydrogen ion commonly referred to as a proton (IUPAC definition). ... A chemical substance is any material substance used in or obtained by a process in chemistry: A chemical compound is a substance consisting of two or more chemical elements that are chemically combined in fixed proportions. ... Hot metal work from a blacksmith In chemistry, a metal (Greek: Metallon) is an element that readily loses electrons to form positive ions (cations) and has metallic bonds between metal atoms. ... A semiconductor is a solid whose electrical conductivity can be controlled over a wide range, either permanently or dynamically. ... Close-up photo of one side of a motherboard PCB, showing conductive traces, vias and solder points for through-hole components on the opposite side. ... A semiconductor is a solid whose electrical conductivity can be controlled over a wide range, either permanently or dynamically. ...

History of etching

The process is known to have been used in Europe in the middle ages, where it was applied to the decoration of armour. One such craftsman, Daniel Hopfer (circa 1470-1536) of Augsburg, Germany, is credited with being the first person to apply the method to printmaking. The Middle Ages formed the middle period in a traditional schematic division of European history into three ages: the classical civilization of Antiquity, the Middle Ages, and modern times, beginning with the Renaissance. ... For other uses, see Armour (disambiguation). ... Daniel Hopfer: Gib Frid - three old women beating a devil on the ground. ... Events May 15 - Charles VIII of Sweden who had served three terms as King of Sweden dies. ... Year 1536 was a leap year starting on Saturday (link will display the full calendar) of the Julian calendar. ... Augsburg is a city in south-central Germany. ... Printmaking is the process of making artworks by printing, normally on paper. ...

Common etchants

Commonly used etchants for copper are:

• Iron (III) Chloride Ferric chloride
• Ammonium persulfate
• Ammonia

Hydrofluoric acid (HF) is a very efficient etchant for silicon dioxide. It is however very dangerous if it comes into contact with the body. Ferric chloride (FeCl3) is an iron-based salt. ... Ammonium persulfate (NH4)2S2O8 has been prepared by H. Marshall by the method used for the preparation of Potassium Persulfate. ... Ammonia is a compound with the formula NH3. ... Hydrofluoric acid is a highly toxic and corrosive solution of hydrogen fluoride in water. ... R-phrases R42 R43 R49 S-phrases S22 S36 S37 S45 S53 Flash point non-flammable Supplementary data page Structure and properties n, εr, etc. ...

Etching in the semiconductor industry

Main article: Etching (microfabrication)

Etching is used widely to manufacture integrated circuits and MEMS. In addition to the standard, liquid-based techniques, the semiconductor industry commonly uses plasma etching. Integrated circuit showing memory blocks, logic and input/output pads around the periphery Microchips with a transparent window showing the integrated circuit inside. ... A mite next to a gear set produced using MEMS. Courtesy Sandia National Laboratories, SUMMiTTM Technologies, www. ... Plasma etching is a form of plasma processing in which a high-speed stream of plasma is shot (in pulses) at a metal. ...

See also

• Etching (art), for printmaking and related uses