GBR code

GBR code, often referred to as Gerber code, is a 2D binary file format used in the printed circuit board (PCB) manufacturing industry to describe the layers of a PCB design. It contains information regarding copper traces, solder masks, silkscreen markings, drill holes, and other features necessary for fabrication.

Gerber files are the standard input for PCB manufacturing equipment, including photoplotters, automated optical inspection (AOI) machines, and direct imaging systems. The format provides a standardized way for PCB designers to communicate their design intentions to manufacturers, regardless of the CAD/CAM software used.

Historically, the term "Gerber code" referred to the original RS-274-D Gerber format, which was a simple ASCII format. However, modern PCB manufacturing generally utilizes the more advanced RS-274-X and especially the Gerber X2 formats. These newer formats embed additional information, such as aperture definitions and layer stackup data, directly within the file, improving data integrity and reducing the risk of interpretation errors. The older RS-274-D format is now largely considered obsolete due to its limitations and reliance on separate aperture files.

The key attributes described within a Gerber file include:

• Geometry: Describes the shapes of conductive traces, pads, vias, and other features.
• Apertures: Defines the shape and size of the tools used to create the geometry. (Less relevant for X2, which includes this info directly.)
• Layer Information: Specifies the purpose and position of the layer within the PCB stackup.
• Drill Information: Coordinates for drilling holes through the board (often contained in a separate Excellon drill file, but sometimes embedded).

The Gerber format is maintained by Ucamco.