What is Excellon

What is Excellon

Excellon is a format or lingo used for inputting data into drill and routing machines. The term originates from Excellon Automation, a prominent company known for manufacturing PCB drilling and routing machines during the 1980s. The Excellon format gained widespread adoption within the industry.

The Excellon format encompasses two versions: Excellon 1 and Excellon 2. Excellon 2 is considered a superset of IPC-NC-349, a standard for numerical control of drilling and routing machines in the PCB industry. Notably, it is possible for commands from both Excellon formats to be mixed within the same file, leading to potential confusion.

While Excellon Automation no longer publishes the specification of its format, an archived copy of the specification exists. However, the interpretation of the Excellon format can vary due to its ambiguous nature, particularly concerning coordinates and units. It is important to note that the format primarily serves as input for drill and routing machines, rather than facilitating CAD to CAM data exchange.