Pulse power supply Overview:
Pulse power supply plating is a powerful means of external bath for metal electrodeposition. It uses the time function to improve the physical and chemical properties of plating coating by changing the pulse parameters, therefore to achieve saving of precious metals and obtain a functional electroplating layer coating purposes. Pulse reverse power supply belonging to a modulation current pulse electro plating, the current it uses is a fluctuation or continuity DC impulse current, so pulse reverse power supply plating is essentially an on-off DC plating.
Pulse power supply waveform type:
There are a variety of Pulse reverse power supply current waveform, the common are square-wave, triangle, ramp, ladder wave. However, the current application, typical pulse reverse power supply generating square wave pulse current is widely used. Thus, the study of pulse plating are generally carried out around the square wave form.
Modulation current power supply plating:
Traditional electro plating is generally as direct current, referred to as DC. DC current is a current direction does not change with time, there is only parameter can be set–current or voltage. 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., commonly to generate these waveforms plating power supply have: silicon rectifier, thyristor rectifier, high-frequency switching power supplies etc..
Disadvantage of DC rectifier compare with pulse power supply:
Not difficult to see, DC with feature of current continuity or duration, not interrupted or changed over time, thus the use of only one parameter – current or voltage to be adjusted. This makes the DC current as a means outside bath control plating quality lack of strength. For example, the DC current are useless in cathode current density increase, inhibit side reactions, and reduce the content of impurities in electroplating, as well as to improve current distribution, etc.
After alternating with pulse signal other signal modulation DC current called as modulation current, modulated current used for plating is called modulated current plating. Modulated current plating existed as mainly used for outer plating tank quality control, it can often play the role that DC rectifier plating can not achieve quality. For example, pulse power supply plating increase several times or even ten times than DC plating cathodic current density, and get detailed crystal plating coating. Modulation current pulse plating generally has: pulse plating, asymmetric exchange plating, DC superimposed plating cycle pulse reverse electroplating.