The Gerber files format is an open vector format for storing PCB designs. It is a standard format in the industry to store and accept PCB images that include copper trace layers, solder masks, drill data, etc.
Prior to the development of the Gerber format, there were no standard guidelines to follow for PCB production. The information for the fabrication of PCB consists of different formats. Usually, vector, descriptive, graphic, and textual formats are used to express the data of the PCB in a comprehensive file.
How to Create PCB Gerber Files
Before starting on the actual Gerber files generation process, it is important to know that different PCB software has individual methods to generate Geber files. In this article, NextPCB discusses three printed circuit board software– Altium designer, Kicad and Eagle.
Gerber File Creation through Altium Designer
To start PCB Gerber file creation with the Altium Designer, you need to add a new OutJob file to your project. Once you are done with adding the OutJob file, you are allowed to configure which manufacturing files you require to generate and the file formats, of course. In this article, NextPCB also has included some images of the following steps to aid your learning process. So, the image below displays OutJob files with several choices available for distinct sets of PCB manufacturing documents. It also includes an option for the Gerber RS-274X files and especially for back-drilled layers of the circuit board. Now, right-click the “Fabrication Output” and however over the Gerber X2 entry to create a new export option for Gerber X2 files.
Altium designers offer the generation of multiple Gerber output sets. The “Backdrill Gerber’s” entry and the “Gerber Files” entry in the above image fall under the RS-274X format. These two option creates PCB Gerber files for specific layer sets. However, once you are done with creating a new Gerber output option, it is significant to configure your desired data to expert with these two functions individually.
The image below displays a dialogue box that will aid you in selecting units, formats, templates, and export layers. Now to select your desired Units and Format right-click them and select the Okay box at the right bottom end of the main dialogue box.
So, we can see the above image is consist of five tabs General, Layers, Drill Drawing, Apertures, and Advanced. There are two primary tabs in the above dialogue box The Layer Tab and The Drilling Tab followed by The General Tab.
NOTE: The above image is from the RS-274X version document. But do not worry, the X2 format will offer you the same dialogue box.
The Layers Tab: This tab allows you to select which layers you want to send to the manufacturers. You can select custom layers from here or send all the PCB layers including the Silk Screen layer.
The Drilling Tab: This tab allows you to select the drilling configurations of your circuit board. This tab basically contains two layers the top and the bottom. But if you have a multi-layer circuit board whose internal layers contain blind or buried vias. You will have another tab to select their configuration.
The other two tabs remain the same.
After this, we will move to NC Drill Files.
Here we select the scale in mm. This dialogue box also provides the option to choose to create two different NC Drill Files for plated and non-platted holes. Then click the Okay box to complete the process.
Now click on the folder and select all the manufacturing documents you want to export. To finish the process of the Gerber File, click on “Generate Content” to complete the process. Never neglect to check the Gerber File before forwarding it. A small mistake at this level can ruin the whole production, which nobody wants.
Gerber File Creation through KiCad
KiCad offers a relatively easier process for Gerber File Generation. All you have to do is to select the desired layers and create a drill file. So, let’s learn with NextPCB how to create Gerber Files through Kicad.
The .Kicad_PCB File
The first step to generating Gerber File through KiCad is to open your desired project. Now, right-click and open the.kicad_pcb template. However, there is another option, select the “PCBNew” tab to open the circuit board editor.
PCB Model to Gerber File
Now on the top left menu select “File” and then “Plot” and then select the desired layers you want to export.
Here is a list of essential layers required for a double-layer PCB.
- The top layer with the title pcbname.GTL.
- The bottom layer with the title pcbname.GBL.
- The upper silk layer with title pcbname.GTO.
- The silk lower layer with title pcbname.GBO.
- The solder mask upper layer with title pcbname.GTS.
- The solder masks the lower layer with title pcbname.GBS.
- The board outline layer with title pcbname.GML/GKO.
- The drill drawing layer with title pcbname.TXT.
The Drill File
After the selection of the required layers click on the Drill File button to generate the “Drill File”. Now at this stage select “Suppress Leading Zeros” and “Minimal Header”. Then to complete the process click on the drill file button at the top right side of the dialogue box.
This is the second last but most crucial step of generating Gerber Files. It includes checking and inspecting the file if it works appropriately before sending it to the manufacturer. For this step open the “Gerb View” and inspect how your PCB looks.
It is the last step which includes compressing all the required files in a .zip format file. And there you are all done with generating Gerber Files through KiCad PCB software.
Gerber File Creation through Eagle
Generate Drill Files
The first step to generating Gerber Files in Eagle is to generate a Drill File. To do so navigate to the top-left side of the menu bar and click “File” then “Run ULP”. A dialogue box will appear with a toggle consisting of two options mm and inch. Select mm and press “Okay”.
Now, click on” File” and then select “CAM Processor” from the drop-down menu.
A pop-up window will appear. Select the “Export as Zip” box. Then open the drop-down “Gerber” option from the left side box and select your required layers and then hit the “Process Job” at the bottom right of the window.
Once the process is complete, inspect your Gerber File and it is ready to forward for manufacturing.
Texts and Fonts for Gerber Files
Texts are one of the basic components of the circuit board. They are used to describe components, and logos, draw symbols, and similar work. Texts make it easier to understand a printed circuit board visually. But writing on PCB is not like writing or printing on paper. The circuit boards are silk-screened with liquid ink usually in white colour. Silk-Screening is a complicated and important procedure for the circuit board, Hence PCB manufacturers give some guidelines to take out the “PCB Printing” process as smooth as they can.
To deal with the silk-screening process some manufacturers advise using vector fonts because they are directly exported to the Gerber Files without any changes. However, the “TRUE TYPE” characters may experience some incompatibility issues. This was for the top and the bottom external layers.
PCB designers and producers also have the option to print on the copper layers. However, not all PCB manufacturers provide this service. So it is better to consult your manufacturer before generating the Gerber Files to avoid any unwanted situation.
Importance of Gerber Files
Gerber files consist of all the necessary information about the manufacturing of the printed circuit board, including the placement of components, the size and shape of the board, and the routes that the electrical signals should follow. This information is crucial for the manufacturer, as it guides them to plan the manufacturing process and ensures that the PCB is made correctly and functions as intended.
As such now you know what Gerber Files are it is easier to explain that without Gerber files, it would be difficult or even impossible to create a functioning printed circuit board. Because, if we do not have proper Gerber files, manufacturers would have to rely on manual measurements and calculations, which would be time-consuming and prone to error. This could result in PCB malfunctioning or even cause serious safety issues.
Hence, Gerber files are incredibly important because they ensure that electronic devices function properly and are safe to use. They are a vital part of the PCB manufacturing process.
Your PCB Manufacturer NextPCB
NextPCB has been offering a one-stop solution for PCB manufacturing, assembling, and testing services for over 15 years. We at NextPCB use the latest technology with every possible approach to carry out complex to high-level Interface Circuit Boards and offer a wide range of PCBs, including metal-core, LED, High-frequency, High-Speed, Waterproof PCBs, and PCB Cameras.
We at NextPCB offer a standard and customized PCB of up to 20 layers with the desired thickness and are willing to incorporate all unique requirements.
Geographically we are located in China. But in a decade and a half, we have built a trustworthy relationship with our worldwide clients.
Gerber files are an essential part of the PCB manufacturing process. They are vector files that contain the necessary information for the production of a printed circuit board. Before the development of the Gerber format, there were no standard guidelines to follow for PCB production. The Gerber format is now the industry standard for storing and accepting PCB images that include copper trace layers, solder masks, drill data, and more.
This article by NextPCB discusses three PCB software, to generate Gerber Files, namely Altium Designer, Kicad, and Eagle. Gerber file provides the manufacturing guidelines to the manufacturer. Hence, it is essential to check them before forwarding them for production, as a small mistake can ruin the entire production process. With the information and instructions provided in this article, you can create Gerber files with ease and ensure that your PCB manufacturing process runs smoothly.
The Article has very little plagiarism because it was a technical guide and I can not change fixed terms like “the RS-274X document” and source links that of sourse other websites used too etc. But if you want me to change it please let me know.