PCB Gerber Files Understanding Their Role in PCB Manufacturing
You may have placed an order for a Printed Circuit Board, and you never like a delay in getting the product delivered. Your PCB manufacturer receives a design file from you, and then he starts arranging everything to fabricate the board based on your given file. However, it is not an easy process. It takes much time from the day of sending the file to the arrival of the board. Some of us feel dissatisfied with our PCB manufacturers for the delay. However, there is no solution to reduce the overall time to design the circuit board.
Gerber files play an important role both as a translator and connector and translator between your PCB manufacturers and design engineers. Manufacturers can easily understand the design engineers’ concepts. It enables them to provide you with reliable and perfect products. Moreover, it ensures an efficient and effective manufacturing process.
What Exactly Is a Gerber File?
A company named Gerber developed the file format- Gerber. At present, this Gerber file format has become the acceptable standard in the software used in the PCB industry. This format describes conditions of board images, like legend layers, soldermask layers, and conductor layers.
Professionals use CAS or EDA systems to design Printed Circuit Boards. These systems help in revealing the board manufacturing details. The information is highly important to start the process of fabricating circuit boards. PCB manufacturers do not have a comprehensive understanding of your PCB design file details when there is no Gerber file format. Gerber format helps in clarifying the design-related needs of every image of the board. You can apply it for both PCB assembly and its bare board creation.
While dealing with the PCB assembly, it is important to add a stencil layer to the Gerber format. Moreover, you have to control the component locations. The file will act as the reference data for your SMT assembly.
To say simply, Gerber PCB files contain some instructions important for designing electrical engineering PCB. After designing the PCB, your third-party manufacturer needs to be provided with those files to maintain precision in building boards. However, the presence of errors in files can result in the production of a defective board. That is why you must focus on documentation.
Gerber files are available in 3 versions. The oldest one of them is RS-274-D, and in due course, RS-274-X has replaced this oldest format. Another popular version is RS-274-X. The latest Gerber format, containing attributes and stack-up data, is Gerber X2.
Importance of Gerber files in PCB Design–
PCB design engineers have to create their unique Gerber files. There are some reasons behind it.
It may not be easy for you to ensure you and your chosen PCB manufacturers are using a particular software application. When the manufacturers’ design software is different from your applications, you have to create Gerber files on your own. Confirmation and conversation can result in the delay of the overall process.
Although your PCB manufacturer’s software is not different from yours, it is safe to create unique uses. Variations in the applied software can cause some errors. Thus, to get the product delivered at the right time and ensure reliability, you have to create a PCB Gerber file.
As a PCB design engineer, you must know the way of generating Gerber files with your own effort. Gerber data is relevant to-
- Conductor layer
- Silkscreen layer
- Soldermask layer
Moreover, when two layers have identical design data, your Gerber PCB files must be created separately to prevent confusion. The steps of generating Gerber files are different for every PCB design software.
How to use Gerber files to manufacturer PCB files
Today, there are technological advancements in every industry, and it is true for the Printed Circuit Board manufacturing sector.
In the past, you could find the trend of using vector photoplotters to generate the tooling film to manufacture PCB. A light ray is essential to pass through an aperture and have contact with the film to turn out the flashes. However, only a limited number of apertures were available to designers. Designers tried to stimulate creativity to restrict lines and flashes to the available apertures.
Nowadays, you can find the use of new machines that have replaced the old and outdated systems. These latest models rely on a laser process to have contact with the film.
When it is a big film with several pieces, lots of lines need to be drawn on it. Thus, the vector photoplotter might take several hours to accomplish the process. To save your precious time, there is a launch of the modern laser plotter.
To serve the purpose of using the original style vector photoplotters, Gerber files were created. The Gerber file provides instruction to the plotter, as it contains minimal information related to the plotter configuration.
The flash has to follow X/Y coordinates, which dictate the position of your aperture. In the past few years, you can notice an increasing functional value in the Gerber PCB data. It comprises details, like aperture definition and other configuration data.
The Gerber data has not lost its value in the modern-day, as the laser plotters rely on it. However, there are no restrictions related to the aperture of the old vector plotters. While converting Gerber, these laser plotters synchronize with the raster file. In this case, Gerber information directs the plotter on what you have to create on the available films. For instance, you may rely on the aperture definitions to relate to the dimension and thickness of pads and traces. On the contrary, there are drawing commands to define the polygon fills and lines to be generated.
In the coming years, you can find more advancements in Gerber files. The tech-savvy PCB manufacturers have started using laser imaging technology directly to the copper for the PCB image creation. They do not need to use a film. They have also become familiar with database formats used for designing PCB images. These images have more detailed data about the circuit board design data. For instance, you can learn more about net connectivity. However, the safest option for you is to continue using your Gerber files in the present format. You must know the role played by them in the PCB manufacturing field.
Gerber file generation in the PCB design–
After creating the design and analysing it repeatedly, you have to take the step to generate your own Gerber files to provide it to the contract manufacturer. However, in this step, you have to rely on your PCB designing software. There are some old, clunky software applications, with which you need to take several steps for the file setup and configuration. But, CAD packages have now reduced your effort.
You have to create individual Gerber files for every layer present on the board. Thus, while your board includes 6 layers in its design with 4 signal layers, the software needs to display these layers separately.
In addition, the bottom and top layers for the solder mask will need unique files. Moreover, you have to deal with the silkscreen layers and solder paste layers but, make sure that your board needs the paste layers and silkscreen layers. Based on the design, you have to decide on it. Some PCB manufacturers apply an additional number of Gerber format layers for the circuit board outline. They make some fabrication, although everything depends on unique data.
Before delivering the files, you need to check out that you have set up standards, formats, and units in the perfect way. They must maintain consistency with the manufacturing and design standards.
You need to create the NC file for a different Gerber file. It sends instructions to the drilling systems related to the circuit board’s house. The file has similarities to the formatted Gerber files, which have information about the drill size and vectors.
Documentation After Gerber Files–
When you think of delivering your files, you have to document the Gerber PCB format and other related manufacturing files. You must do it in a way that the manufacture creates the design based on your instructions. Assembly drawings and fabrications are also valuable. One of the smartest ways to minimize is to work with a reliable manufacturing partner. Look for professional engineers and designs to get the best service from them. They will also let you learn more about the PCB design.
