Gerber File Generation

In the PCB design layout industry, there are so many EDA software to make the PCB layout, now we list the main

and popular software for your reference:

l  Cadence Allegro

l  Eagle

l  Altium

l  Mentor Graphics -PADS

 

Now let us talk about the fabrication file generation:

 

Cadence (Allegro)

To generate the Gerber file , open your PCB layout in Allegro and click Manufacture>>Artwork . 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.

To generate the NC Drill file, go back to Manufacture > NC > NC Drill

The NC Drill dialog box will open. Confirm that Root file name is present (board name.drl) and select Auto Tool

Select.       Click on the Drill button to generate the NC Drill file

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.

Altium

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.

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.

Mentor Graphics -PADS

With the .pcb opened in PADs Software, Go to File > CAM

The ‘Define CAM Documents’ window will open and here you can click on the various CAM documents to choose

to generate for your project. Choose ‘Run’ to generate the files.

To generate the NC Drill only, from the same window (Define CAM Documents) Choose ‘NC Drill Drawing’…

Summary will describe the selections for the current document chosen. For instance, 

when you choose NC Drill Drawing, the holes and vias will be described in the Summary section. ~ Choose Run

to generate the drill file.