What are Gerber files?
Gerber files is the standard file used by PCB Manufacturing Company to manufacture a PCB according to the specifications required to describe the images of the printed circuit:copper layers, solder mask, legend, etc.
A Gerber PCB file is a two-dimensional pictorial representation of each layer of a PCB board where traces, pads, and vias are represented by different lines and shapes. It is the universal way to tell a machine how to make a PCB board based on the information provided. The Gerber file is the first step in the PCB fabrication process.
It is a PCB design standard widely accepted by manufacturers and customers.
Currently, many PCB manufacturers only support Gerber File.Taking JLCPCB for example, which is a popular PCB company and insists $2 for 1-4 layer PCBs.
JLCPCB only accepts Gerber files in RS-274x format for copper layers, solder mask and legend layers, mechanical layer and SMD paste layers.
How Gerber Files are Used in PCB Manufacturing
PCB production innovation used today has advanced significantly over the past few years. Previously, vector photo plotters were used to make the tooling film used in PCB manufacturing measurement. Light directed through a gap was used to open the film to create the glows and patterns for each individual cushion and track.
There were only an insignificant number of accessible gaps and planners must be innovative in limiting their blazes and lines to only those gaps that were accessible to them. These more experienced vector machines have now been superseded by a newer variety which uses a raster laser cycle to uncover the film. For larger parts of film with a ton of lines drawn on them, a vector based photoplotter could take many hours. This time has been reduced to just a few minutes with a laser plotter.
The history of Gerber documents can be traced back to the requirements of early vector photo plotters. To give the plotter directions, a Gerber record contained negligible plotter arrangement data, and X/Y arranges followed by a glow or drawing order and the aperture situation to use. The usefulness of Gerber information grew throughout the year; it currently incorporates additional arrangement data as well as scale and aperture definitions.
The laser plotters used today actually use similar Gerber data, but the aperture limitations of most established vector plotters at this point make no difference. Laser plotters convert Gerber files into a raster recording, and this data teaches the laser plotter how, where, and what to do on the videos. For example, aperture definitions convey the thickness and size of chases and cushions while draw orders characterize whether lines, polygon fills, or flares should be made. At this point, the laser erases the film uncovering the image as it goes.
However, time does not stand still and the world of Gerber documents continues to evolve. PCB manufacturers have now started using direct laser imaging to create images of PCBs directly on copper, and bypassing the film requirement. There are also new dataset layouts that are used to create PCB images that contain much more nifty board layout information, such as internet network information. However, it is safe to say that Gerber documents will remain in excess in their current structure for some time to come, and you should be aware of the role they play in PCB fabrication.
Instructions for generating Gerber files in a PCB design
Once your plan is complete and the final check is done, the next step will be to create the Gerber records for your PCB producer. The way to achieve this varies depending on the PCB layout programming you are using. Some more established instruments may find many ways to set up and produce records, but today most CAD sets have worked their way up to creating these records.
Normally the Gerber records you need to create will be an individual document for each actual layer in the array. If your PCB layout is six layers with four layers of signs and two planes for force and ground, then you need to turn these layers into six Gerber documents. Additionally, you must produce a separate Gerber document for the top and base binder layers, top and base screen layers (if required), and top and base solder glue layers (if required). The measurement of the screen print and glue layers will depend on whether your plan requires screen print and glue on both the top and bottom of the board. A few producers may request additional Gerber layers for map layouts or data creation and collection; however, these solicitations are mostly for new plane configurations.
You will also need to organize the Gerber record generator before you create the documents so that the units, configurations, and guidelines are set up consistently with your plan standards and your manufacturer's principles. Although not a Gerber record, an NC Drill Document is normally created alongside Gerber records. This tape tells the boring machines used by the panel maker where to enter openings in the panel. This record is basically the same as a document designed by Gerber in that it additionally contains borehole size data and vector information for the various borehole areas.
Conclusion:
Finally, be sure to properly document your Gerber, NC Drill, and other fabrication files so your contractor can build the board to your intent. You will need to create fabrication and assembly drawings, pick and place data, test data, a list of schematic networks, and a readme file to complete the process. The best thing you can do is to work with your CM ahead of time to know exactly what they need from you to get the best results.
