Gerber File format

No one needs a delayed printed circuit board (PCB) order. The ideal circumstance is that you send your design file

to PCB manufacturer, then the manufacturer arranges board fabrication based on your file and deliver products to

you. The practical situation, however, is not that simple.

It usually takes such a long period of time from the moment you send your designed file out to your boards' final

arriving. Your dissatisfaction towards your PCB manufacturer will rise as turn time increases. Actually, there's

much you can do to cut this time period during the whole procedure from your perspective. After all, it's

effectiveness and efficiency that account for you.

Gerber files do play a crucial role as a connector and translator between PCB design engineers and PCB

manufacturers, enabling design engineers' considerations and concepts to be understood by manufacturers so

that correct and reliable products can be effectively and efficiently manufactured.

Definition and Necessity of Gerber Files

Initially developed by a company with the name of Gerber, Gerber format currently refers to a widely accepted

standard PCB industry software sticks to, capable of describing circumstances of board images such as

conductor layers, soldermask layers, legend layers.

Printed circuit boards are designed in a specialized EDA (Electronic Design Automation) or a CAD (Computer-

Aided Design) system that further generate board manufacturing data based on which circuit board fabrications

are commenced. PCB manufacturers won't fully understand all details of a PCB design file unless Gerber format

file is contained in it as reference and guidelines. Gerber format file is applied to describe design requirement of

each image of a circuit board and it can be applied for both bare board fabrication and PCB assembly.

When it comes to bare board fabrication, Gerber format is called for by both standard photoplotters and other

manufacturing equipment desiring image data like legend printers, direct imagers or AOI (Automated/Automatic

Optical Inspection) equipment etc. put it simply, Gerber format files have to be depended from beginning to the

end of PCB fabrication process.

When it comes to PCB assembly, a stencil layer is included in Gerber format and component locations are

regulated as well, which will be regarded as significant reference data for SMT (Surface Mount Technology)

assembly, thru-hole assembly and mix of them.

Versions of Gerber Files

Nowadays, three versions of Gerber formats are available:

• Gerber X2 - the newest Gerber format with stackup data and attributes contained.

• RS-274-X - an expanded version of Gerber format and it has been widely applied.

• RS-274-D - the oldest version of Gerber format which is being gradually replaced by RS-274-X.