A corrosion is also called the etching, circuit board factory in the processing circuit board process of an important working procedure, so in the process of corrosion need to pay attention to those points?
First is ammonium chloride content, by chemical etching liquid regeneration party shall, whether the
+ regeneration requires the presence of excess ammonia and ammonium chloride, if the opposite time slow, so that lose the ability of etching.
But if when in etching liquid chlorine ion content too high, can cause corrosion resistant coating eroded.
The amount of ammonium chloride in the etching liquid should be controlled at about 150 g/L.
Finally, temperature control, generally said, as the temperature rises, the etching speed faster.
When the etching liquid temperature below 40 ° C, moment speed rate will slow down, can lead to increased lateral erosion;
The temperature above 60 ° C, the etching rate significantly increased.
But easy to cause large amount of ammonia volatilization, environmental pollution and make the etching liquid composition ratio.
Usually in the temperature control in 45 - best corrosion
From the etching liquid stability, control of low temperature (
Below 40 ° C)
On the PCB side good corrosion and corrosion of liquid pH stability.
But, in turn, the time is very slow.