If you're anyway related to electronics, either a hobbyists, or an engineering student, or someone who's currently working in the field of electronics, then its almost impossible that you don't know about PCB Design
PCB Design or printed circuit board design is the process of giving a solid form to a circuit we create on paper. Short form of Printed Circuit Board is what we commonly call as PCB. PCB Design is an art and science at the same time, because, you need to know about the electronic components, their current flow and related things in order to design PCB and, you must be artistic enough to make your pcb look good. You might have heard about the Steve Job's obsession about making things beautiful inside a computer, and it also involved, how the PCB's looked, and how the tracks bent on the board :)
What are the major steps in PCB Design to know?
For anyone to be able to design PCB's, few things are important to be known first which are
Familiarity with Electronics Components
Understanding of PCB Footprint which is also called as package
Understanding of Copper Sides in the PCB that you're using, single or double sided
Component Placement, proper component placement is most crucial in designing boards
Routing, you need to know the requirements of current to flow from the PCB tracks that you're going to design, what are the requirements, and whats the relation between track size and the maximum current it allows to flow
How PCBs are Designed?
PCB Design, in old days, was mostly done on paper, where one has to just draw the Artwork on paper, usually a graph paper to get proper idea of dimensions and then place the component footprints on the paper by drawing them. Last step was to interconnect those components using tracks drawn simply with pencil. In many academic institutes, this is the primary step of how PCB design is taught to students and its for the better because you get the core concept of it when learning it for the first time.
Initially, everyone learns about single sided PCB's where there's copper only on one side of PCB and over time, the PCB design learning becomes much more complex when we know about creating a dense PCB in a small size. So then comes double sided PCBs where there is copper on both sides, so designer can place components as well as route tracks from both sides of PCB. And from this time and on, most designers shift to using Computer Aided Tools for PCB Design (CAD)
What are popular CAD PCB Design tools?
There are many PCB design tools available in market, many of them are free, many of them are paid versions. And selection of the PCB design tool completely depends on what suits best for your requirement. Am just giving few names here based on how popular they are and how costly the are, but offcourse, there's much more than this list
Mentor Graphics PADs, perhaps the most expensive PCB Design tool used by many corporate product design companies
Proteus Design Suite, more preferable due to both PCB design and electronics simulations that comes under single package
Altium(previously protel) provides a complete design suite with 3D visualization and overview about how PCBs will fit into its enclosure
OrCAD one of the oldest software
Eagle undoubtedly, eagle pcb design software can be called as the most dominant and most popular tool because its used by both industries and hobbyists community around the world, and with flexible pricing, its affordable for even a single person startup
KiCAD one of the most popular 100% free PCB design tool
EasyEDA complete cloud based 100% free online and powerful pcb design tool
The list goes on and on and its just based on trials and erros that you've to chose the tool appropriate for you
Importance of Learning PCB Design
If you're a student studying engineering or someone who is willing to start his own startup, its very important to understand and learn at least the basics of PCB design. As engineering student, knowledge of basic single sided PCB design is something kind of compulsory thing to know about. You can download any of the above software or try easyEDA directly on cloud without downloading the software on your computer and start experimenting with it right away
Now, we all know that the most developments, everyday are happening in the field of electronics, there are new mobiles, new IoT devices, and lots of new gadgets and researches going on, and all of this needs product design which involves PCB design as primarly skill. And in the era of Arduino's and Raspberry Pi, its easier to find a programmer or embedded developer but day by day, its getting difficult for startups to find a good PCB designer, why? because people are simply ignoring studying PCB designs.
Which software to choose?
Whether you're a student looking for job or a hobbyists who wants to make nice fun projects for himself for the coming weekend, learning PCB design by choosing appropriate tool becomes very important. My personal suggestions is not only one but I've 2 recommendations
Choose eagle if you either plan to start a company in future, or wants to design hobby circuits which are small one. These are 2 ends of a string. Because eagle free version allows a fairly small size of PCB to be designed so it should fit only small circuits and eventually you might want to buy it.
But the benefit with eagle is immense, first of all, its a completely powerful tool with all the features you might need, secondly, almost every open source hardware design available on internet is made using Eagle, so adaptation is easier
Free limited version is available
Large user libraries available for almost every part to be used
Number of open source projects made in eagle, makes it easy to adopt
Very little learning curve
Small size installation
If you're comfortable using a completely cloud based software where all your designs are also saved on cloud, then easyEDA is one of the best choices because of many reasons
Takes no installation, runs on cloud
Learning curve is simple
User contributed parts library is large
Based on these 2 things, you can choose whichever is best for you after experimenting.
For those interested in knowing the basics of PCB design, here's my explainer video which will create most of the doubts for beginners
Having said that, all the best for your PCB design learning journey, comment your views on available free software tools and your learning experiences. Happy learning!!!