PCB Gerber Documentation: Introduction and Industrial Impor

PCB Gerber Documentation: Introduction and Industrial Importance

Each electronic component is manufactured to specification. Specifications and other design details are documented in various documents. A Gerber file is one such file used in the electronics industry to store and communicate design blueprints. This file is primarily for reference by PCB designers and manufacturers for prototyping or mid-volume production. Having said that, you may have several questions, such as what exactly are these Gerber files? How do they help users during the manufacturing process? These questions can be answered through this article.

Introduction to Gerber files

Gerber is an ASCII vector format used for PCB design, hence the name PCB Gerber file. It is an open source format for defining PCB design specifications such as copper layer counts, drilling data, solder mask information, etc. Typically, the PCB design process involves Electronic Design Automation (EDA) or Computer Aided Design (CAD). For CAD PCB layouts, PCB Gerber files are the standard input format used to present the image of the design. It provides image standards for PCB manufacturing data and 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 used in the industry.

What information is contained in these files and how does it help in PCB manufacturing? The next section will answer these questions in detail.

Important Features of Gerber Files

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

lConfiguration parameters:

Gerber files usually contain configuration parameters. The syntax starts and ends with a text block of %. However, configuration parameters may vary depending on the type of Gerber file. Configuration parameters control each activity the Gerber file is performing.

lMacro and aperture size:

Apertures define the shape and size of the PCB board, while macros define geometric features that are rarely used in Gerber files. These may include logos, letters or registration marks. In CAD systems, macros are AM parameters that fill in the gaps between original features and specifications.

lDrawing commands:

Gerber files have three drawing primitives, such as burrs, arcs, and lines, to define thickness and geometry in PCB designs. With the "step and repeat" command in RS-274X, it is possible to draw more complex shapes in the design, which was not possible before.

lX/Y coordinates:

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

What is the importance of Gerber files in PCB manufacturing?

The following points are the importance of Gerber files in the PCB manufacturing industry.

l As mentioned earlier, PCB designs are becoming more and more complex, requiring the use of small components in complex and compact designs. In this case, the vector photoplotter tools previously used were not sufficient.

l The compact design consists of multiple layers. Older vector photoplotters could only track single-layer designs and component locations. And PCB Gerber files are even available for PCBs with more than 20 layers. This is where Gerber files play an important role in the PCB fabrication and fabrication industry. The PCB Gerber file is suitable for multi-layer PCB design because it tracks solder layers and component locations layer by layer, so it can be traced layer by layer.

l Actually, early vector plotters required focused light that was sent through an aperture to expose the design film. These photoplotters are not suitable for modern compact, high density and complex PCB designs. Gerber files use a laser plotter to track component locations, which are suitable for high-density component mounting on PCBs.

lPCB Gerber files are also handy. Typically, for a larger PCB, there may be many traces and component locations drawn on it, so the Photo Plotter tool can be time consuming. However, with the help of a laser plotter, Gerber files reduce the time to just a few minutes.

l If you need to go back to a traditional photo plotter, it is very easy to trace back the information in the Gerber file. Using a laser plotter, Gerber coordinates can be converted to a raster file, which helps keep track of information over time. In this way, all these potential functions of the PCB Gerber file become very important during the PCB manufacturing process. In addition to these features, there are a few features that make them even more important in the process.