Pulse rectifier plating principle:
Pulse rectifier plating is a powerful tool to control metal outer tank electrodeposition. It uses the time function to improve the physical and chemical properties of the plating coating film by changing the pulse parameters, to achieve savings in precious metals and obtain a functional electroplating coating film purposes. Pulse rectifier electro plating belongs modulation current plating, its current is a fluctuation or on/off DC rush current, therefore, is essentially on-off DC plating. There are a variety of pulsed current waveform, commonly as square wave, triangle wave, sawtooth, order staircase wave etc.. However, in application situation, typical pulse power generated square wave pulse current is widely used.
Modulated current plating:
Conventional electroplating is generally used in the form of direct current, referred to as DC. DC current is a current direction continuous steady and does not change with time changing. DC current waveform common as single-phase half-wave, single-phase full-wave, three-phase half-wave, three-phase full-wave, DC or steady current, etc.. While to generate these waveforms power supply are, silicon-controlled rectifier, high-frequency switching power supplies. DC current with features of continuity or continuity, without interruption to control plating coating film outside the bath. Such as DC current increase cathode current density, inhibit side reactions and reduce the content of impurities in the electroplating coating, to improve current distribution, etc. are useless.
DC current after pulsing signal or other modulating alternating signal is called as modulation current, as well as the plating process under condition of modulation current is carried as modulation current plating. Modulated current plating mainly generated and existed to play a role to control outside bath plating coating quality. It can get the effect that the DC current plating can not achieve. For example, the pulse plating increase several times or even ten times more than direct current plating cathodic density, and get more detailed crystalline coating. Modulation current normally has pulse plating, asymmetric exchange electroplating, DC overlay plating cycle for the several forms of direct plating and so on.
Current pulse plating is actually used by a DC on-off, but when on DC peak current equivalent more than ordinary DC current times or even tens times. it is this high instantaneous current density make the metal ions in the very high overpotential to reduce, so that the grains become fine deposit layer. Pulse rectifier plating is widely used in electronic circuits of the electronics industry, connectors, printed circuit, electroplating integrated framework, the stem, etc., these products can be greatly improved the performance of electronic devices, and significant saving precious metals. Pulse rectifier plating is currently the most widely used and one of the largest gains modulation current plating.