Printed circuit board (PCB) etching is the process of eliminating unnecessary copper from a PCB to make the desired circuit pattern. This process typically involves several key steps to etch, prepare and develop PCBs efficiently. These steps are outlined below:
PCB Preparation
The copper surface of the PCB is cleaned to remove dirt, oil, or oxides that could interrupt the etching process. A resist material is then applied to the copper surface to shield the areas that will form the circuit traces. The resist can be applied in numerous ways, such as screen printing, photolithography, or toner transfer.
PCB Development
If you are using photolithography, your PCB is exposed to UV light through a film mask. The exposed spot of the resist hardens, while the unexposed areas remain soluble. The unexposed resist is eliminated using a chemical developer solution, leaving behind the expected circuit pattern.
PCB Etching
The PCB is immersed in a chemical etching solution, like ferric chloride or ammonium persulfate. The etching solution melts the unprotected copper, leaving behind the circuit traces protected by the resist. The etching process is carefully observed to confirm that the desired amount of copper is removed. Once the etching is finished, the PCB is removed from the etching tray that contains the solution and rinsed thoroughly to halt the etching process.
Discover the Best-in-Class PCB Etching, Preparation & Developing
Enrgtech offers a variety of PCB Etching, Preparation, & Developing products to customers in the United Kingdom and worldwide from reliable manufacturers. Additionally, our extensive selection of PCB etching, preparation, and developing products includes:
- Transparency Film: High-quality sheets are built to create sharp, clear PCB artwork, and they are ideal for transferring designs onto your boards during the etching phase.
- Etching Accessories: Indispensable tools and equipment, including tanks, brushes, and protective gear, to facilitate smooth and precise PCB etching operations.
- Etching Chemicals: Reliable chemical solutions, such as ferric chloride and ammonium persulfate, are formulated to efficiently remove unwanted copper from PCBs.
- Deionisers: Advanced systems for refining water used in PCB processes, guaranteeing contaminants are eliminated to obtain clean and flawless results.
Things You Should Do After the Etching Process
- Remove the Resist: Remove the remaining resist using a chemical stripping solution.
- Cleaning & Finishing: Clean and finish the PCB to prepare it for further processing, such as soldering or assembly.
Safety Precautions
PCB etching involves the use of various chemicals that can be hazardous to human health. Proper safety measures, including wearing gloves, eye protection, and a lab coat, are essential. The etching process should be carried out in a well-ventilated space to avoid inhaling hazardous fumes.
