There are a variety of chemical solutions used in PCB etching, depending on the resist type and production conditions. Here are some common chemical solutions:
1. Acidic copper chloride: This is a common etching solution, suitable for etching PCBs whose resist layers are organic resists such as acid ink, photodrying film, and photowetting film.
2. Alkaline copper chloride: suitable for etching PCBs whose resist layers are tin, tin-lead, nickel/gold and other metal resists.
3. Ferric chloride: also commonly used to etch PCB.
4. Sulfuric acid and hydrogen peroxide: used together to etch PCB.
5. Persulfate: also a common etching solution.
The above information is for reference only. If necessary, it is recommended to consult professionals in relevant fields.