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SPR curves measured during the adsorption of a polyelectrolyte and then a clay mineral self-assembled film onto a thin (ca. 38 nanometers) gold sensor. One of the first common applications of surface plasmon resonance spectroscopy was the measurement of the thickness (and refractive index) of adsorbed self-assembled nanofilms on gold substrates.
Gold is a good conductor with a resistivity of 2.44 × 10 −8 Ω·m and is essentially nonmagnetic: = 1, so its skin depth at a frequency of 50 Hz is given by = = Lead, in contrast, is a relatively poor conductor (among metals) with a resistivity of 2.2 × 10 −7 Ω·m , about 9 times that of gold.
Gold cyanidation (also known as the cyanide process or the MacArthur–Forrest process) is a hydrometallurgical technique for extracting gold from low-grade ore by converting the gold to a water-soluble coordination complex. It is the most commonly used leaching process for gold extraction. [1]
Doping of a pure silicon array. Silicon based intrinsic semiconductor becomes extrinsic when impurities such as Boron and Antimony are introduced.. In semiconductor production, doping is the intentional introduction of impurities into an intrinsic (undoped) semiconductor for the purpose of modulating its electrical, optical and structural properties.
The Czochralski method, also Czochralski technique or Czochralski process, is a method of crystal growth used to obtain single crystals of semiconductors (e.g. silicon, germanium and gallium arsenide), metals (e.g. palladium, platinum, silver, gold), salts and synthetic gemstones.
Demonstration of ultrasonic wedge bonding of an aluminium wire between gold electrodes on a printed circuit board and gold electrodes on a sapphire substrate, reverse bonding order. The main classes of wire bonding: Ball bonding; Wedge bonding; Compliant bonding; Ball bonding usually is restricted to gold and copper wire and usually requires heat.
Mechanical stresses, high currents, and corrosive environments forming of whiskers and short circuits. These effects can occur both within packaging and on circuit boards. Formation of silicon nodules. Aluminium interconnects may be silicon-doped to saturation during deposition to prevent alloy spikes. During thermal cycling, the silicon atoms ...
Copper is also harder than gold, which makes damage to the surface of the chip more likely. However copper is cheaper than gold and has superior electrical properties, [1] and so remains a compelling choice. Almost all modern ball bonding processes use a combination of heat, pressure, and ultrasonic energy to make a weld at each end of the wire.