The PCB fabrication process involves several steps to create a functioning circuit board. It begins with a design plan that satisfies the blueprint specifications of the board and ends with a fabricated PCB ready for assembly. Each step requires careful attention to detail and machine-driven tools to avoid errors. The final board will need to pass rigorous electrical tests before it can be soldered and assembled with other components.
The first step of the PCB manufacturing process is the creation of a physical board, starting with a substrate made of fiberglass. This serves as the core of the board and provides strength against bending or breaking. A layer of copper is then added, either as a foil layer or a full-on copper coating. This is what will carry electrical signals to and from the inner layers of the board, much like your nervous system carries messages between your brain and your muscles.
Once the designer has completed the layout of the board using a CAD application, they will need to save the files in Gerber format. The CM will then need to review the file and approve it for fabrication. This is known as a Design for Manufacture (DFM) check and ensures the file will be able to be fabricated to the designer’s specifications.
A local PCB contract manufacturer will need to cultivate partnerships with local fabricators who can provide quick turn-arounds on bare boards. These fabricators will also be able to answer questions and provide engineering support on the PCB layout. The CM may also choose to partner with overseas fabricators for larger orders that require quicker turnaround and lower costs.
The next step is to prepare the layers for imaging and copper etching. Once the inner layer pairs are stacked together with a sheet of “prepreg” between them, they will be exposed to heat and pressure in a lamination press. This will fuse the layers into a single board.
Each layered panel will then be subjected to an automated optical inspection (AOI) machine. This will scan each panel for signs of defects and compare them to the original Gerber file it received from the designer. If there are any issues, the panels will be rejected.
Once the layers are prepared, the outer layer images will be etched and cleaned using various chemicals. Then the drilled holes will be plated with a thin layer of copper, creating plated through-holes (PTH) for connections to other components on the board. Once the etching and drilling is complete, the copper will be plated with a gold finish for additional protection from corrosion. The plated board will then undergo another round of AOI testing and a final QC inspection. Once the QC passes, the boards will be ready to ship. They will be shipped in protective packaging that protects them from dust and other environmental conditions. If you’re looking for a partner to help with your PCB manufacturing, contact us today! We’ll help you find the right solution for your needs.