Technical Articles

Open source/commercial PCB design softwares and common output formats

Are you a professional PCB designer? Are you a hobbyist? Are you a student? Is the cost major constraint for you? Are you happy to spend reasonable amount for professional software?

All these questions lead to a quest of finding the most suitable PCB design software for your needs. The common criteria to consider while selecting your PCB design software are –

• License cost
• Complexity of your design
• Scalability requirement of your project
• Design and import/output restrictions
• Restriction on choosing your PCB manufacturer

PCB design softwares available in the market can be divided into two major categories – Free or Open source softwares and commercial softwares. Here is a list of softwares you may consider for your needs:

Free or Open source PCB design softwares*

Caution:

• Please check whether the software works on your operating system. Some works only on Linux or Macintosh.
• Few softwares restrict you to manufacture PCB from their own manufacturing facilities by not allowing to export output in commonly acceptable formats.

Commercial PCB design softwares*

Name of the software	Website link
Altium	http://www.altium.com
Eagle	http://www.cadsoftusa.com (EAGLE light edition is free for limited usage mainly for hobbyist)
Orcad	http://www.orcad.com
Easy-PC	http://www.numberone.com
Circuit Maker	http://www.circuitmaker.com
PADS	http://www.pads.com
CR-8000/CR-5000/ CADSTAR	http://www.zuken.com/en

* There are many free and commercial softwares available in the market but we have included only few that are widely used among designers.

Fabrication Output Formats:

In most cases, PCB manufacturer will not accept your PCB design file directly (e.g. QualiEco do not accept direct design files from any software except Altium. Just supply .PCB or .PCBDOC file to us and you are done). You will be required to export fabrication output from your design files in a specific format. Therefore, it is extremely important to know various possible fabrication output formats before you chose PCB design software. If your software cannot export fabrication output in commonly acceptable formats, you will stuck with only few PCB manufactures and end up paying high cost of manufacturing.

Here is list of common output formats:

1. Gerbers and NC drill format

This is the most common and easily acceptable fabrication output format by every PCB manufacturer in the world. There are two major generations of Gerber format: RS274-X (extended gerber) and RS274-D (standard gerber). Standard gerber format is almost obsolete these days. However, if your software can only generate standard format, please do not forget to supply separate aperture list/report file to the manufacturer. Manufacturer’s CAD engineer will use aperture list to enter shape and size information manually in their CAM software.

NC drill file should be in ASCII format look something like this:

%
T01
X035Y0075
X03525Y01225
M30

2. ODB++ (Open DataBase++) format

ODB++ format has been designed with an aim to eliminate all problems for CAD-to-CAM data transfer without any downsides. Unlike gerbers and NC drill data, ODB++ is a single file contains all the information that is needed for PCB manufacturing. There are contradictory opinions about the accuracy and ease of gerbers and ODB++ formats among PCB experts. However, we consider ODB++ outputs more reliable than any other format.