In the PCB manufacturing process, the etching step is a core procedure that defines circuit precision and ensures product reliability. The selection of etchant is critical to production efficiency, process stability and overall costs. As an important acidic etching material, sodium persulfate is widely used in the processing of various PCB substrates and different process scenarios by virtue of its excellent adaptability, controllability and operational safety, emerging as one of the key etchants supporting the high-efficiency production of the industry.
Ⅰ. Basic Properties and Etching Mechanism of Sodium Persulfate
Sodium persulfate is a strong oxidizing inorganic compound, appearing as a white crystalline powder that is highly soluble in water. It dissociates in aqueous solutions to form ions with strong oxidizing capacity. Its core etching mechanism is based on redox reactions. Under acidic conditions, sodium persulfate can oxidize copper atoms on the surface of PCB substrates into water-soluble ionic forms, while undergoing reduction itself, thus achieving the selective removal of copper layers.
Ⅱ. Core Advantages of Sodium Persulfate as a PCB Etchant
(1) Etching Performance Advantages
Balanced and Controllable Etching Rate
The reaction rate of the sodium persulfate etching system is relatively moderate and easy to regulate. Precise rate matching can be achieved by fine-tuning parameters such as concentration and temperature. This characteristic helps avoid over-etching or under-etching of circuits caused by rate fluctuations, providing core support for ensuring circuit precision.
Good Etching Uniformity
With optimized process parameters and the addition of appropriate additives, sodium persulfate enables relatively uniform etching of copper layers. It contributes to forming circuit patterns with smooth edges and no burrs, reducing the incidence of micro-defects and providing a high-quality surface base for subsequent processes.
Wide Adaptability
Sodium persulfate can be applied to a variety of PCB substrates (including some rigid and flexible boards) and has good compatibility with common additives in etching solutions. It can adapt to the production requirements of different line widths and processes without major formula adjustments, covering mid-to-high-end PCB manufacturing scenarios.
As a National Single Champion Enterprise for Sodium Persulfate recognized by the Ministry of Industry and Information Technology, Fujian Zhanhua Chemical relies on a strict full-process quality control system and large-scale production capacity to ensure excellent consistency of core indicators such as oxidation activity and purity for each batch of products. Its product performance stability far exceeds the basic industry standards. With years of in-depth industry experience, Zhanhua Chemical’s sodium persulfate can be stably adapted to various PCB process scenarios. Combined with a sound supply chain guarantee, it lays a solid quality foundation for the mass production of enterprises.
(2) Process Operation Advantages
Easy Regulation of Process Parameters
The sodium persulfate etching system features mild reaction conditions. Key process parameters (such as concentration and temperature) have a wide adjustment range and are easy to control. Operators can flexibly adjust them according to substrate types and circuit requirements without complex technical control means, reducing process operation difficulty and the risk of human error, and adapting to large-scale assembly line production.
Strong Stability of Etching Solution
Compared with some traditional etchants, the sodium persulfate etching solution is not prone to spontaneous decomposition and deterioration during use. The concentration of active ingredients remains stable, resulting in a longer service life. The stable performance of the etching solution can reduce the frequency of solution replacement and avoid product quality consistency issues caused by fluctuations in solution performance.
Relatively Convenient Etching Solution Management
Under standardized process control, the sodium persulfate etching solution can maintain a stable working state for a long time without frequent supplementation and adjustment. In addition, its waste liquid has a relatively simple composition, and the subsequent neutralization and treatment processes can be easily integrated into standard wastewater treatment systems, resulting in relatively low environmental pressure.
Fujian Zhanhua Chemical focuses on the scenario-specific adaptation and optimization of sodium persulfate products. The sodium persulfate it produces has excellent compatibility with the conventional wastewater treatment processes of PCB enterprises, which can be seamlessly connected without additional modification of treatment equipment, helping enterprises reduce process transformation costs.
(3) Cost and Safety Advantages
Controllable Raw Material Costs
The production process of sodium persulfate is mature, and the market supply is sufficient, enabling effective control of procurement costs. At the same time, its stable etching efficiency and the recyclability of waste liquid through conventional recovery processes not only improve resource utilization rate, but also further reduce raw material consumption per unit product and overall production costs.
High Operational Safety
Compared with some highly corrosive and irritating etchants, sodium persulfate poses lower direct risks to operators and equipment under standardized operation and routine protective measures. Its reaction process is stable, without potential safety hazards such as violent exothermic reactions or large gas emissions, significantly reducing production safety risks.
Through a strict production quality control system, Fujian Zhanhua Chemical ensures high product purity, low impurity content and stable and controllable performance, avoiding safety hazards caused by raw material quality issues from the source. In addition, the product has excellent stability under standardized use conditions, creating a safer production environment for PCB enterprises.
With its stable oxidation characteristics, sodium persulfate exhibits unique advantages in etching uniformity, process controllability and operational safety, making it particularly suitable for PCB production scenarios with specific requirements for etching rate, circuit precision and operating environment. In practical selection, enterprises need to conduct a comprehensive evaluation based on specific substrate types, circuit precision, production capacity requirements and environmental specifications, and select suitable etching systems and process parameters.