Understanding PCB Gerber Files: Key Role in Electronics Manufacturing

Jun 25,2020

Every electronic assembly is built to specifications. The specifications and other design details are documented in various files. Gerber file is one such file that is used in the electronics industry for storing and communicating blueprints of design. This file is mainly referred by PCB designers and manufacturers for building prototypes or during mid to full volume production. Having said that you may have several questions like what exactly are these Gerber files? How do they help users during the process of manufacturing? These questions are answered through this post.

Introduction to Gerber Files

Gerber is an ASCII vector format that is used for PCB design, therefore it is called PCB Gerber files. It is an open-source format, which is used for defining the PCB design specifications like the number of copper layers, drill data, solder mask information, etc. Generally, the PCB design process involves Electronic Design Automation (EDA) or Computer-Aided Design (CAD). In the case of CAD PCB layout, PCB Gerber files are used to present the image standard input format of the design. It offers an image standard for PCB fabrication data, it also involves automated optical inspection (AOI).

There are three formats of PCB Gerber files namely, RS-274X, RS-274D, and Gerber-X2. RS-274X is the current format that is being used in the industry.

What information is included in these files and how they aid in PCB manufacturing? The next section answers these questions in detail.

Significant Features of Gerber Files

The features of Gerber files that make this format stand out in PCB manufacturing are as follows.

• Configuration Parameters:

  Gerber files usually include configuration parameters. The syntax begins and ends with text blocks of %. However, the configuration parameters may vary according to the type of Gerber files. Configuration parameters control every activity being performed by Gerber files.

• Macro and Aperture Dimensions:

  Aperture defines the shape and size of the PCB board, whereas macros define rarely used geometrical features on Gerber files. These may include logos, letters, or registration marks. In a CAD system, macros are AM parameters that are used to fill gaps between original features and specifications.

• Drawing Commands:

  Gerber files possess three drawing primitives such as flashes, arcs, and lines to define the thickness and geometrical shapes in a PCB design. With the help of the “step and repeat” command in the RS-274X, it is possible to draw complex shapes in design which earlier was not possible.

• X/Y Coordinates:

  Gerber defines X and Y coordinates of each geometric shape drawn on Gerber file design as placeholders. Due to all these features, PCB Gerber files are an important format in PCB fabrication. They act as PDFs for the electronics manufacturing industry.

What is the importance of Gerber files in PCB Manufacturing?

The following points refer to the importance of Gerber files in PCB manufacturing industries.

• As discussed earlier, PCB designs are getting complex, and the use of small components is required in complex and compact designs. In such cases previously used vector photoplotter tools do not suffice.

• Compact designs are constructed of multiple layers. The older vector photo plotters were only capable of tracing the single-layered design and component locations. Whereas, PCB Gerber files are suitable for even more than 20 -layer PCBs. That is where Gerber files play an important role in the PCB manufacturing and fabrication industry. PCB Gerber files are suitable for multiple layered PCB designs as it traces layer by layer construction, along with the solder paste layers and component locations.

• In fact, earlier vector plotters required a focused light that was sent through an aperture to expose the design film. These photo plotters are not suitable for modern compact, high-density, and complex PCB designs. Gerber files implement laser plotters to trace the component locations which are suitable for high-density component mounting of PCBs.

• PCB Gerber files are also time-convenient. Generally, for a larger piece of PCB, which may have a lot of trace line and component locations drawn on it, Photo Plotter tools can be time-consuming. However, Gerber files cut down that time to just a few minutes with the help of a laser plotter.

• In case if there is a requirement of going back to conventional photo plotters, then the information on Gerber files can be traced back very easily. Gerber coordinates are converted into a raster file by using the laser plotter which helps in keeping the traces of information for a long duration. All these potential abilities of PCB Gerber files make then very important in a PCB fabrication process. Along with these abilities, there are some features that make them even more important in the process.

These PCB Gerber files can be created by using several software products. However, if you are unable to do it yourself then you can source this service from trusted PCB manufacturers like Creative Hi-Tech. They perform Gerber file creation from scratch for their clients, as a part of their PCB manufacturing services. The company has been offering PCB assembly and manufacturing services since 1998 to several industries. 

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