Мыс қосылу процесі және оның қолданылуы

Process of electroplating copper

Copper electroplating is the process of electroplating a layer of copper onto the surface of a metal object. Copper is used both as a standalone coating and as an undercoat onto which other metals are subsequently plated. The copper layer can be decorative, provide corrosion resistance, increase electrical and thermal conductivity, or improve the adhesion of additional deposits to the substrate.

Copper fluoroborate baths are similar to acid sulfate baths, but they use fluoroborate as the anion rather than sulfate. Pyrophosphate baths contain cupric pyrophosphate as a source of copper(II) ions, potassium pyrophosphate as a source of free pyrophosphate that increases bath conductivity and helps with anode dissolution, ammonia for increased anode dissolution and deposit grain refinement, and a source of nitrate ions such as potassium or ammonium nitrate to decrease cathode polarization and increase the maximum allowed current density. When the bath is made up, the copper pyrophosphate and potassium pyrophosphate react to form a complex, [K6Cu(P2O7)2], which dissociates to form the Cu(P2O7)26− anion from which copper deposits. Variations of the pyrophosphate electrolyte include general purpose baths, strike baths, and printed circuit baths. Printed circuit baths typically contain organic additives to improve ductility and throwing power. Copper plating is also used for minting currency.

Copper electroplating sees widespread usage in the manufacture of electrical and electronic devices, owing to copper's high electrical conductivity – it is the second most electrically conductive metal after silver. Copper is electroplated onto printed circuit boards to add metal to the through holes and fabricate the board's conductive circuit traces. This is done either through a subtractive process where copper is plated as a blanket unpatterned layer that is subsequently etched with a patterned mask to form the desired circuitry (panel plating), or through an additive or semi additive process where a patterned mask that exposes the desired circuitry is applied to the board followed by copper plating onto the unmasked circuit areas (pattern plating). Copper is also used to plate steel wire for electrical cabling applications. As a soft metal, copper is also malleable and so has the inherent flexibility to maintain adhesion even if a substrate is subject to being bent and manipulated post plating. When electroplated, copper provides a smooth and even coverage which therefore provides an excellent base for additional coating or plating processes. Corrosion resistance is another advantage to copper. Although copper is not as effective at resisting corrosion as nickel and so is commonly used as a base layer for nickel if enhanced corrosion protection is needed; typically the case for materials that are required to work in marine and subsea environments. Lastly, copper has anti bacterial properties and so is used in some medical applications.