Gerber files are essential requirements when fabricating a PCB design into the actually printed circuit board. The PCB layout files are readable to computers and plotters, eventually printing the layout on the board. If you are an Altium Gerber designer, you need to understand the various types of Gerber files and circumstances when they are best required. However, the Gerber files are all based on the American standard code for information exchange. Therefore, you can choose to use any of the options available without worrying about the industry standards.
Gerber files explained
A Gerber file is a skeleton presentation that demonstrates a single-sided or double-sided printed circuit board. They are useful in the fabrication of PCBs because they provide complete information about the PCB. The details include the number of layers, board outline, traces width, solder paste, and the drill holes.
When making the PCB, the Gerber files give instructions to the plotter to produce a particular photo. However, you might experience some issues regarding the Gerber files. For instance, the Gerber files will not provide the X, Y coordinates of the holes on the board. You must generate a numerically controlled drill file as a fabrication output file using CAD software.
You also need a read-me file to provide instructions because the Gerber files are not self-explanatory. During the fabrication process, you need to run the design for manufacturing check first because the Gerber files will not provide any information about the silkscreen, so you might end up drilling the incorrect holes.
Types of Gerber files
1. RS274D Gerber files
The RS274D Gerber is a file format designed with separate Gerber files for a single layer attribute such as solder mask, copper traces, and silkscreen. They also contain an aperture file, but it is not embedded in the Gerber file. You must generate it manually, and the process can cause errors because it is difficult to read the ASCII characters. The RS274D Gerber files are an older version and have become obsolete since a newer version was introduced. However, you will still find the older PCB layouts in the market, and many fabrication factories still use the RS274D Gerber file format.
2. RS274X Gerber file
The RS274X Gerber file is an enhanced and extended version of the RS274D Gerber file. This Gerber file contains the macro definitions and aperture file embedded as standard output. The RS274X Gerber file is considered the standard Gerber file format commonly used in the PCB fabrication process. This format is highly compatible and recommended for advanced laser and raster photo plotters. Designers utilize the flexibility of the RS274X Gerber file in designing various image shapes based on their needs. The Gerber files offer high reliability and precise method to create perfect image files for copper shapes, signal layers, and power planes.
3. Gerber X2
The Gerber X2 is a newer version that extends the RS274X Gerber file. It comes with image data of printed circuit board layouts, including the information about through-holes, layer stack-up, drill size, layer span, drill locations, and other information regarding the PCB prototype assembly. The Gerber X2 and RS274X are almost similar file formats because they support similar data files in the PCB fabrication process.