1. Application field: A large amount of micro-etching solution, etching solution, copper nitrate, etc. containing different concentrations of copper are produced in the production process of PCB industry

2.Application system

System categoryCoating type
Micro etching solutionTitanium-based iridium tantalum
Alkaline etching solutionTitanium-based iridium tantalum
Acid etching solutionTitanium-based Ruthenium Iridium

3. Current density: (200-400) A/m2

4. Service life: 12-24 months

5. Process flow:

A. Micro-etching solution (Cu2SO4+H2O2) oxygen-breaking electrolytic cell (decomposition of H2O2) electrowinning copper

B. Alkaline etching solution, extraction process, copper sulfate + sulfuric acid, electrowinning copper

C. Acidic etching solution, ion-exchange membrane electrolysis (electrowinning copper), exhaust gas treatment (absorption of chlorine gas)

6.Electrochemical performance and life test (reference standard HG/T2471-2007 Q/CLTN-2012)

NameStrengthen weightlessness mgPolarizability mvOxygen evolution/chlorine potential VTest Conditions
Titanium-based iridium tantalum≤1<40<1.451mol/L H2SO4
Titanium-based Ruthenium Iridium≤10<40<1.131mol/L H2SO4

7. Product use background and introduction:

A large amount of micro-etching solution, etching solution, copper nitrate and other metals containing different concentrations of copper and other metals are produced in the production process of PCB industry. The recovery value is high, and there will be a small amount of copper heavy metal in the discharged wastewater. On the one hand, it causes a serious waste of resources. On the other hand, heavy metals leak into the soil and water after being discharged, which will cause serious pollution and harm to the natural environment on which we live and our own health.

1) Micro etching solution

Micro-etching solutions include sodium persulfate/sulfuric acid system and hydrogen peroxide/sulfuric acid system, which have been widely used in PCB surface treatment processes in recent years, such as: copper deposition (PTH) process, electroplating process, inner layer pretreatment, green oil pretreatment In production lines such as processing and OSP processing, direct electrolysis will damage the anode coating.

2) Etching solution

In the electronic circuit board (PCB) etching process, the copper content in the etching solution gradually increases. For the etching solution to achieve a better etching effect, each liter of the etching solution needs to contain 120 to 180 grams of copper and the corresponding amount of etching salt (NH4CI) and ammonia (NH3). The etching solution regeneration cycle system has acidity and alkalinity, and the two systems can be divided into extraction method and direct electrolysis method. It can reduce and regenerate a large amount of the used etching solution that originally needs to be discharged into a regenerated etching solution that can be reused. Thereby, the discharge of production waste liquid can be reduced, the recycling can reduce the production cost, and high-purity electrolytic metal copper can be extracted.