Schematic and PCB Design

Easy-to-use PCB design software has enabled millions of beginners and experts alike to quickly produce their own customized, high-quality printed circuit boards (PCBs). Once reserved for professionals or those brave enough to dabble with messy chemicals and complex lithography, boards can now be realized using easy home production methods, 3D printing solutions, or batch production services that can turn around finished products within days for mere dollars.

Designing and making PCBs can open up new avenues for anyone, from hobbyists to small businesses. For the many projects that struggle to make it off of a breadboard, PCBs offer more robust, reliable, and compact finished solutions. And for those feeling more creative, PCBs are no longer limited to green rectangles. They can be any shape or color, transparent, and even flexible. This allows for near limitless opportunities to create stunning items of PCB art or inventive “badgelife” conference badges.

In this article, we’ll explain how design software helps you create the information necessary to produce a physical PCB. We’ll also consider the various requirements of users, from beginner to expert, and the functionality offered by free design tools, including the availability of training materials and online support communities.

The Ins & Outs

Even a simple PCB requires a multitude of parameters to be collated, including component lists, physical layouts, interconnection paths, physical dimensions, and much more. PCB design software helps designers manage all of this by efficiently visualizing the entire design process. These programs are a subset of more sophisticated electronic design automation (EDA) software tools, which are intended for professionals and include additional specialized functionality. The terms “PCB design” and “EDA” are therefore often used interchangeably.

All programs reviewed in this article support the two main steps in the PCB design process and a third important area of functionality that binds them together. Let’s look at each of these in turn.

Circuit Design & Schematic Capture

This step supports the capture of the underlying circuit design (the circuit diagram, if you like) and involves the following activities:

Creating a circuit diagram or schematic to connect all of the components
(Optional) Validating the design using “rule checks” or simulations
(Optional) Creating lists of components in a Bill of Material, for example

Industry-standard netlist files, which describe the circuit, are produced at this stage. In some cases, this functionality is implemented as a standalone module. In others, it’s integrated with the next step.

Layout Design

This step helps convert a circuit diagram, also called a schematic, into an actual PCB design and involves the following:

Designing the physical layout and taking the size, or footprint, of the various components and connectors into account.
Routing the electrical tracks between components (on one, two, or multiple layers).
Helping design, among other things, the shape of the board, the locations and sizes of holes, solder and paste masks/stencils, other silk screens, and artwork.
(Optional) Visualizing the finished design in 2D or 3D.

A finished PCB design is captured in a set of Gerber files – an industry standard used by all manufacturers – as well as files with additional information, including the locations and sizes of drill holes.

Component Libraries

PCB design software libraries support and simplify both of the above steps by providing important information about the multitude of components (passive parts, ICs, and modules) found on a PCB:

Information on how components should be represented on a circuit diagram, their electrical and connection characteristics, physical “footprint”, and appearance, among other things.
Access is provided to pre-populated component information and, sometimes, the ability to manually modify or add components to improve the quality and speed of the design.
PCBs can optionally be produced by independent third parties or large suppliers to simplify manufacture.

In addition, PCB design software is often packaged with functionality to allow designers to work collaboratively, integrate with mechanical designs, or manage commercial production.

Not surprisingly, professional-grade software comes with a price tag. For hobbyists, small businesses, and more sophisticated designers, however, there are many powerful solutions available for free.

Choosing a Program

There’s a wide range of free design tools out there, from classic open-source offerings to sophisticated software designed for professionals. The market has changed a great deal in recent years, with the hobbyist and small business space now dominated by KiCad, EasyEDA, and free offerings from Altium. Yet, these options shouldn’t necessarily be automatic go-tos, as others are often more suitable for many users.

Below, we’ve highlighted the best free PCB design tools available in 2022. None of our choices are especially difficult to use. However, all require a commitment to learn a little about PCBs and get up to speed on how to put a circuit together.

Deciding which is best depends on several factors, including what platform the software runs on (e.g. PC, Mac, or Linux) or whether it’s browser-based and therefore accessible using a variety of devices. The intended use of the PCB has a bearing, as does the user’s prior level of electronics and PCB experience. For each of the featured programs, we suggest one or more of the following levels based on the programs’ functionality:

Beginners: Instead of rich functionality, those who are relatively new to electronics or PCB design typically value an intuitive user interface (UI), ready availability, easy-to-understand training materials, friendly help forums, and simple worked examples.
Educators and students: For educational use, whether teaching beginners in secondary school or electronics students in advanced degree programs, the appropriate level of basic functionality is key, as is the availability of training materials and support oriented towards teaching and learning. University-level students may also accept a higher learning curve to gain valuable experience with advanced professional tools.
Advanced designers: Designers with experience, perhaps working professionally, typically look for tools that are capable of handling more complex designs, have the ability to simulate circuits, and offer opportunities to collaborate on and share designs with others. Extensive library functionality may come in handy. The availability of knowledgeable online communities, more evolved examples, and templates, are also important.
Professionals: Professional users have additional demands for sophisticated design support, advanced PCB modeling (for heat or RF interference, for example), more powerful collaboration, functionality to help manage design versions, and the ability to integrate with production supply chains (such as materials management).

Other considerations that may affect tool choice include the level of support for special applications, for example, PCB art or RF solutions. Designers who share an interest in software engineering may be influenced by the ability to write new functionality, software plug-ins, or even to play a role in coding the next generation of tools.

A final point is that experienced PCB designers often use more than one tool depending on the task at hand. Once you’ve mastered one, the others are relatively easy to pick up. So don’t sweat the choice; choose a program that looks like it roughly fits your needs, play around in the program, and have fun!

KiCad

KiCad is one of the most well-known free electronics and PCB design programs. First created almost 30 years ago, it’s now on version 6 and has been extensively upgraded over the last year with significant UI and editor improvements, new design management utilities, and better support for plug-ins. Backed by prominent organizations like the Raspberry Pi Foundation, Arduino, and CERN (European Organization for Nuclear Research), KiCad enjoys an active community and hosts a well-attended annual conference.

The open-source program boasts a powerful suite of features, meeting the needs of beginners and experts alike. In addition to the usual circuit schematic design, PCB layout tools, and 3D visualization, KiCad integrates circuit simulation (Ngspice), supports Git for version control, and links with FreeCAD for other generic 3D designs. In addition, a growing list of plug-ins provides extension opportunities ranging from RF design to PCB art using Python.

The new version addresses previous criticism of being “not intuitive”, and the new UI is very well-regarded. KiCad also boasts a well-established user base that’s active in online forums and a wide variety of online tutorials, from simple to complex.

Also updated is KiCad’s library approach, which was previously somewhat old-fashioned. It now holds its own against other offerings, and multiple third-party libraries are also available.

Levels: Beginners, educators and students, advanced designers
Type: Offline with unrestricted functionality
Operating systems: Windows, MacOS, Linux
Developer: KiCad Developers Team

Altium Designer

As was already mentioned, Altium is one of the leading providers of EDA and PCB design solutions. Their premier design package, Altium Designer, is intended to provide an “uncompromising PCB design experience” for professionals. License fees are normally well over $1,000 per year, but students (with a valid university email address) can gain access for free for six months (on a renewable basis) during their studies.

The software has all of the functionality normally associated with free solutions and much more, allowing students to use state-of-the-art circuit simulation, advanced board design, commercial-level collaboration and management, and more. It also boasts an extensive component library.

The learning curve to understand all of the features can be steep, although high-quality eLearning materials are available free of charge. Students also get access to extensive community support with a very active and experienced forum for all users.

Levels: Educators and students, professionals
Type: Offline with time-restricted access (for educational use)
Operating systems: Windows, MacOS, Linux
Developer: Altium