What is PCB Fabrication Notes (Fab Notes)

What is PCB Fabrication Notes (Fab Notes)

PCB fabrication notes, or fab notes, are specific instructions and requirements included in a PCB fabrication drawing or provided as a separate text file. These notes serve as a means of communication between the designer and the fabricator in the PCB industry. They convey important details and information necessary for the successful manufacturing of a PCB board.

The purpose of PCB fabrication notes is to ensure that the design is accurately fabricated according to the specified requirements. While there is no strict standard for what should be included in these notes, they typically cover various aspects of the fabrication process. This includes details such as manufacturing instructions, assembly specifications, industry standards, and manufacturing tolerances.

Additionally, PCB fabrication notes may include information about the locations of special features on the board, such as gold fingers, via-in-pad, and blind/buried vias. They may also specify requirements for controlled impedance, solder mask color, silkscreen information, and plating details.

To streamline the process, designers can use templatized fabrication notes provided by different design or fabrication houses. These templates can be customized with design-specific points and then sent to the fabricator for review, eliminating the need to rewrite all the fabrication notes for each design.