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Electroless nickel immersion gold (ENIG or ENi/IAu), also known as immersion gold (Au), chemical Ni/Au or soft gold, is a metal plating process used in the manufacture of printed circuit boards (PCBs), to avoid oxidation and improve the solderability of copper contacts and plated through-holes.
Before plating, the surface of the material must be thoroughly cleaned. Unwanted solids left on the surface cause poor plating. Cleaning is usually achieved by a series of chemical baths, including non-polar solvents to remove oils and greases, as well as acids and alkalis to remove oxides, insoluble organics, and other surface contaminants.
An unfinished surface is often called mill finish. Surface finishing processes can be categorized by how they affect the workpiece: Removing or reshaping finishing; Adding or altering finishing; Mechanical processes may also be categorized together because of similarities in the final surface finish.
An example of a physical change is a change in the outward appearance. An example of a mechanical change is a change in tensile strength or surface hardness, which is a required attribute in the tooling industry. [16] Electroplating of acid gold on underlying copper- or nickel-plated circuits reduces contact resistance as well as surface hardness.
Surface finish, also known as surface texture or surface topography, is the nature of a surface as defined by the three characteristics of lay, surface roughness, and waviness. [1] It comprises the small, local deviations of a surface from the perfectly flat ideal (a true plane ).
Electroless nickel-boron plating developed as a variant of the similar nickel-phosphorus process, discovered accidentally by Charles Adolphe Wurtz in 1844. [2]In 1969, Harold Edward Bellis from DuPont filed a patent for a general class of electroless plating processes using sodium borohydride, dimethylamine borane, or sodium hypophosphite, in the presence of thallium salts, thus producing a ...
The holiday season is incomplete for many people without holiday movies. This year, Netflix is streaming a wide range of Christmas classics and original movies.
Electropolishing, also known as electrochemical polishing, anodic polishing, or electrolytic polishing (especially in the metallography field), is an electrochemical process that removes material from a metallic workpiece, reducing the surface roughness by levelling micro-peaks and valleys, improving the surface finish.