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A Gerber file opens as project, which can be edited if you want. Add arc, rectangle, polygon, path, and merge polygons. A built-in tool lets you create double sided PCB by inverting layers. It also features a script tool, known as TCL console, which helps users to implement their own features to PCB designs. Check the Gerber files in GerbView Next, click ‘ Close ’ to exit the Drill and Plot windows. All of the files should have appeared in your gerbers folder. KiCAD comes with a gerber viewer called GerbView, you can open the “GerbView” and check what your board looks like before sending it to manufacturer. With your.pcb file opened with Altium Designer software, click FileFabrication OutputsGerber Files sequently. Then, Gerber Setup dialogue window will come out, in which five items are available for engineers to set corresponding parameters in their Gerber files: General, Layers, Drilling Drawing, Apertures and Advanced. You can open Gerber files with a number of programs, most of which are free. These free Gerber viewers include ​ grbv, GraphiCode GC-Prevue, PentaLogix ViewMate, and Gerbv. A few of them support printing and viewing the measurements. You could also use Altium Designer to open the Gerber file but it isn't free. Double click 'Gerber Files' it will open Gerber setup. Use the same steps as above and click ok. Enable output generate option and set target folder location. Clock Run or double click over generates content. The gerber file outputs will be generated. Figure 1: Sample PCB Design file. In figure 1 different layers names are shown in their.

1. Altium Gerber Files

RS-274-X Gerber file format is a defacto data sharing standard for PCB manufacturing. This is basically a printer or plotter language which is used for PCB CAM (Computer Aided Manufacturing) data generation. Almost everyone who uses Altium Designer software for PCB design, either hobbyist or commercial designer, may have used this feature. It is actually a 2D ASCII file format.

Gerber file format is evolved from applications where it is used to re-create images or graphics i.e., printers and plotters industry. In the same way it is used in electronics hardware industry to print PCB tracks, vias, pads, text, holes, clearances and all information which is contained in a *.PcbDoc design file. The Altium Designer software tool has a feature to create and gerbtool option to verify data as well.

Like other softwares outputs the Altium Designer gerber file can be divided into four subparts:

• Configuration Parameters
• Aperture Definitions
• Drawing Commands
• X/Y Coordinates

Each file extension denotes a specific layer such as:

Top Layer => *.gtl

Bottom Layer => *.gbl

Keepout Layer => *.gko

TopOverlay Layer => *.gto

BottomOverlay Layer => *.gbo etc.

2. Generating Gerbers in Altium Designer

Add layer stackup to any of the mechanical or other suitable layer.

Add other information like manufacturing notes, dimensions, cutouts etc., before generating gerber files.

In Altium Designer it is very easy to setup Gerber Files creation setup. It is done by two ways:

Generate through File>Fabrication Outputs> Gerber Files

It opens Gerber Setup dialogue box.

In Gerber setup dialogue box Set file producing unit system.

In layers pane add layers to be re-produced in gerber format.

In drill drawing pane click plot all used layer pairs on both of the boxes.

Set apertures box.

Set advanced parameters in advanced pane or otherwise keep default settings.

Click ok , it generates the gerber outputs in the project folder.

On same method NC drill files are created i.e., File>Fabrication Outputs> NC Drill Files and then adopt the same steps as above.

Or in other way it can be generated by following steps:

Output Job File to project > Fabrication Outputs> Gerber Files and then set path for files.

Double click 'Gerber Files' it will open Gerber setup. Use the same steps as above and click ok.

Enable output generate option and set target folder location.

Clock Run or double click over generates content. The gerber file outputs will be generated.

Figure 1: Sample PCB Design file

In figure 1 different layers names are shown in their respective layer. The same layers can be viewed in the final view Figure 5 as Gerber output generated.

Figure 2: Gerbers Settings Dialogue Box

Figure 3: Gerber Setup Dialogue Box opens

Figure 4: Gerber Files generated and viewed in CAMTastic Bottom Layer view

Figure 5: CamTastic complete PCB view

3. What is Needed by Manufacturer

In a gerber file following layers and information should be added:

1. 1- Enable all signal layers which have been used for routing in PCB design or those which have electrical signals routing should be enabled to re-produce in gerber format.
2. 2- Enable all plane layers which are solid copper and distribute power to the circuit on PCB. These are printed as negative image of layer.
3. 3- Enable Keepout layer, it is usually electrical boundary of the board. The keepout can also be asked to manufacturer for cutting boundary.
4. 4- Enable required mechanical layers in gerber setup. A mechanical layer does not have any electrical information like in signal layer or plane layers. However, they can have some information about mechanical parameter like PCB cutting or, 3D PCB footprints information, assembly and fixing in enclosures etc.
5. 5- Enable Top Overlay and Bottom Overlays which have information of components designators and PCB name, number, nomenclature debug information and test signal details etc.
6. 6- Dimensional Information: PCB Dimensions information should be added on top overlay or mechanical or keepout layer of PCB design file before generating gerber files.
7. 7- Layer PCB stackup: Before generating gerber files add layer stackup information in any enabled mechanical layers so that manufacturer can use information about PCB material such as base material thickness, pre-preg thickness type etc.
8. 8- Preferably produce time and date stamped Gerber files so that they would be back traced for any query.
9. 9- Recheck and verify the file types using any gerber viewer software tool.
10. 10-If found accurate and forward to the manufacturer.

Figure 6: Gerber files enable and disable and extensions

Figure 6 shows the gerber files produced by Altium Designer software, produced time, type of layer etc.

3. Summary:

Gerber format is RS-274-X 2D ASCII file format. The gerber file format is a defacto standard of interface between a PCB Design engineer and manufacturer. It includes all conductive, mechanical, text and keepout layers information of a PCB design alongwith necessary notes for manufacturing.

The Altium Designer software produces RS-274-X format Gerber files by different methods. The latest software and updates about files generation are available on Altium ®. In this tutorial a complete yet comprehensive guide has been provide.

No one needs a delayed printed circuit board (PCB) order. The ideal circumstance is that you send your design file to PCB manufacturer, then the manufacturer arranges board fabrication based on your file and deliver products to you. The practical situation, however, is not that simple.

It usually takes such a long period of time from the moment you send your designed file out to your boards' final arriving. Your dissatisfaction towards your PCB manufacturer will rise as turn time increases. Actually, there's much you can do to cut this time period during the whole procedure from your perspective. After all, it's effectiveness and efficiency that account for you.

Gerber files do play a crucial role as a connector and translator between PCB design engineers and PCB manufacturers, enabling design engineers' considerations and concepts to be understood by manufacturers so that correct and reliable products can be effectively and efficiently manufactured.

Initially developed by a company with the name of Gerber, Gerber format currently refers to a widely accepted standard PCB industry software sticks to, capable of describing circumstances of board images such as conductor layers, soldermask layers, legend layers.

Printed circuit boards are designed in a specialized EDA (Electronic Design Automation) or a CAD (Computer-Aided Design) system that further generate board manufacturing data based on which circuit board fabrications are commenced. PCB manufacturers won't fully understand all details of a PCB design file unless Gerber format file is contained in it as reference and guidelines. Gerber format file is applied to describe design requirement of each image of a circuit board and it can be applied for both bare board fabrication and PCB assembly.

When it comes to bare board fabrication, Gerber format is called for by both standard photoplotters and other manufacturing equipment desiring image data like legend printers, direct imagers or AOI (Automated/Automatic Optical Inspection) equipment etc. put it simply, Gerber format files have to be depended from beginning to the end of PCB fabrication process.

When it comes to PCB assembly, a stencil layer is included in Gerber format and component locations are regulated as well, which will be regarded as significant reference data for SMT (Surface Mount Technology) assembly, thru-hole assembly and mix of them.

Nowadays, three versions of Gerber formats are available:

• Gerber X2 - the newest Gerber format with stackup data and attributes contained.

• RS-274-X - an expanded version of Gerber format and it has been widely applied.

• RS-274-D - the oldest version of Gerber format which is being gradually replaced by RS-274-X.

PCB design engineers should never be too lazy to generate their own Gerber files for the following two reasons.

You are hardly able to make sure the PCB design software you're using is the same as that is being used by your PCB manufacturer. If your PCB manufacturer uses different PCB design software, you have to generate Gerber files by yourself, further conversation and confirmation will definitely cause more time and delay the production process accordingly.

Even if PCB manufacturer uses the same PCB design software as you do, you are still advised to generate Gerber files on your own since difference in terms of applied software may also lead to possible errors.

Therefore, in order to ensure delivery time and reliability of end products, PCB design engineers should learn to generate Gerber files on their own. Gerber files generally contain design data of conductor layer, soldermask layer and silkscreen layer. Furthermore, when it comes to two layers with the same design data, Gerber files should be still generated respectively to avoid possible misunderstanding.

Different PCB design software feature different operation steps of Gerber files generation. In the following part of this article, Gerber files generation methods will be displayed concerning PCB design software.

Altium Designer

With your .pcb file opened with Altium Designer software, click File>>Fabrication Outputs>>Gerber Files sequently. Then, Gerber Setup dialogue window will come out, in which five items are available for engineers to set corresponding parameters in their Gerber files: General, Layers, Drilling Drawing, Apertures and Advanced.

• General button

Under General button, two parameters should be determined: Units and Format. For Units, either Inches or Millimeters can be selected. For Format, three alternatives are supplied. The highest resolution is 2:5 whereas the lowest resolution is 2:3.

• Layers

In this tab, layers to plot and to mirror should be determined. Cross can be marked at the end of layers that need to be plotted or mirrored. Mechanical layers to add to all plots can be neglected.

How To Make Gerber File

Gerber File Types

• Drill Drawing

Little should be done in this tab and Legend symbols don't matter much.

• Apertures

Based on the discussion talked about previously in this article, Embedded apertures (RS274X) should be ticked with other items becoming grey and no further actions are required.

• Advanced

Parameters in Film Size can be set as default by Altium Designer and error may be caused if these parameters are set to be too small. Parameters in Aperture Matching Tolerances, both Plus and Minus should be set to be 0.005mil.

In Batch Mode item, Separate file per layer should be selected.

Leading/Trailing Zeroes, Position on Film and Plotter Type should be selected based on PCB design engineers' preference and demands of specific projects. Leading/Trailing Zeroes and Position on Film determined in Gerber Files should be compatible with that in NC Drill Files.

Among selections in Other item, it is suggested that Optimize change location commands and Generate DRC Rules export file (.RUL) be ticked while the other two selections not.

After all the parameters have been determined, press OK button to complete Gerber file generation.

Cadence (Allegro)

Open your PCB layout in Allegro and click Manufacture>>Artwork sequently. Then Artwork Control Form will be seen.

Then it's time to add a board outline by right-clicking on the TOP folder and picking Add Manual.

Determine a film name, OUTLINE for example and click OK.

In the Subclass Selection window, expand BOARD GEOMETRY and tick in front of OUTLINE. Then, click OK button.

Back to Artwork Control Form window, tick in front of OUTLINE if it has stayed in the area of Available films.

With those steps finished, press Select all button with all the layers output. Then, Gerber files will be generated when Create Artwork button is clicked.

EAGLE

Open your PCB layout with EAGLE software and click File>>CAM Processor. Then you'll encounter a popup dialog.

In this dialog window, click File>>Open>>Job and open a design file in a new window that is shown below.

In this window, you should define Gerber files in terms of Component side, Solder side, Silk screen CMP, Solder stop mask CMP, Solder stop mask SOL, Border, Paste CMP, Paste SOL and Silk Screen SOL. As soon as all parameters under all buttons in this window have been determined, you can generate Gerber files by clicking Process Job button.

In my opinion, it's not a difficult job to create a Gerber file in PCB design software as long as you're fully aware of the significance of it for engineers from PCB manufacturers. Remember: create a Gerber file for EACH layer of your PCB together with PCB edge. A clear and integrated Gerber file will definitely drive your order to be effective and efficient.

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