Copper Etchant Options

Copper etching is a vital manufacturing process that tends to be used in the manufacturing of printed circuit boards but can also be used to manufacture copper parts in the chemical machining industry. If you are interested in utilizing copper etching to make a product, to start off you should know that there are simply 3 different etchants you can utilize: Ferric Chloride, Cupric Chloride, and Alkaline Etch. Here are some short explanations of those etchants so that you can get a better understanding of which one would suit your product/process best.

Ferric Chloride

Ferric chloride (FeCl3), as mentioned in some of the previous blog posts, is a highly capable etchant widely used in the chemical machining industry. Since it has the capability to etch both iron and copper-based metals, it can be used to manufacture a wide array of products. Therefore, if you want to etch both iron and copper, this would ideally be the etchant for you. Although it can be used to etch both, there is a certain limit to etching of different metals. Through the chemical machining industry, it is almost an unwritten rule that you do not etch different metals in a single ferric chloride bath. If you must, you should utilize the etchant to etch your iron-based metals first before you etch your copper metals. This is because the more copper you etch the more likely you will receive a dark and hard-to-remove residue on your iron metals. By doing this, you will also be able to make your ferric chloride last longer. With fewer copper ions in the solution, it will be easier to monitor and regenerate your ferric chloride and thus reduce the cost of etching.

Cupric Chloride

Cupric chloride (CuCl2), sometimes just referred to as cupric, is a highly efficient etchant for copper. It is considered efficient because of the regenerating capabilities it has. Since it can be effectively regenerated, the cost of etching is can be drastically reduced. On top of that, it is easy to maintain because of its simple chemistry with copper.

Alkaline Etch

Cupric alkaline etchant (Cu2+ (NH3)4Cl2), also known as, alkaline etch, is a solution that is also utilized to etch copper. This etchant may be the most widely used among those in the printed circuit board industry. It is perhaps the most used in that industry because it tends to have a higher etch rate and improved etch factor than cupric chloride – it also is compatible with most metallic resists. The main pitfall this etchant has is that it is considerably more difficult to maintain than the other etchants.

If you would like to know more technical information about these etchants, please visit our technical information page and see some of our process guidelines papers. You can also contact us with any questions you may have about your copper etching process.