Overview
Many engineers want to be a good PCB design engineer but they lack the knowledge of how to go about it. It is not easy to know what all steps are required, which all the skills to learn.
TIP: Start with basics, have patience while learning, be consistent in putting in time every single day, work hard. More designs you will make better designer you will become.
A good PCB design engineer should know following things:
1. Basic Electronics
PCB is very central to any electronics design, so good understanding of electronic components, it’s interfaces, is fundamental. If you really want to be a great PCB design engineer, knowledge of electronic components is important. It is analogous to how an embedded firmware developer should know the embedded hardware to be a good embedded design engineer. One good video is here.
2. Basic knowledge of PCB
Printed Circuit Board(PCB) is nothing but a fiber board which keeps electronics components together in a most optimized space and provides an electrical connection between them. One should be aware of basic terminologies [1], [2],[3], [4] used. It is good to know how it acts as a component in an electronic design, how tracks, pads, vias, power planes, etc. works. Also, how these PCBs are manufactured. This helps in understanding many design rules which are directly related to manufacturing or physical nature of PCB.
3. PCB Design Software
Next is good knowledge of using at least one PCB design software. One should know how to draw schematic, component placement, PCB layout, create component library, generate gerber, review via Gerber viewer tools. There are many PCB design software available in the market but it is advisable to pick the one which is widely used in the industry. Some time back I did an online research and created a comprehensive list of popular PCB design software available in the market. I have also mentioned my recommendation, which tool could be considered to learn.
4. PCB Layer Stack-up
When designing a multi-layer board, a very clear understanding of PCB layer stack up is critical for the first time right design. Here is a document which explains it well.
5. PCB Design Rules
There are many common design rule which need to followed while designing a PCB. Some rules are explained in the videos available here. They fall under the following category:
- General rules
- Noise reduction, EMI/EMC considerations, signal integrity rules
- Considerations for thermal integrity (heat dissipation due to power circuits)
- Considerations for power integrity (power loss in the traces)
- Design for test like what all considerations are required so that testing of the boards is made possible. Some of the things like adding test points, accessibility of signal (which need testing) on the top or bottom side of the board, etc.
- Design for manufacturing rule like track width, clearance, via/pads size, drill size, etc. One need to understand manufacturability constraints w.r.t to the design and also it’s impact on the cost. Her is a comprehensive guide.
6. 3D Model / Mechanical Design
These days most of the PCB Design software provides a way to add 3D models of the components and see how the PCB will look like after it gets manufactured and components are assembled. Using 3D models for each component any issues related to inter-component spacing, etc. could be detected early during the design phase itself and helps save PCB revisions effort, cost and time. Sometimes it helps to quickly do few mock-ups of PCB with connector, etc. and see how PCB will look like and also plan for mechanical enclosure, if everything will fit in properly or not, how it will look like, etc.
7. Detailed design review process
Design reviews are very critical to make first time right design. I recommend three level of reviews. First is done by the designer itself (self-review) then next review should be done by the hardware engineer (can be a joint review) and then a final review by another independent qualified engineer or an external consultant would be really good.
Two bonus points for a PCB design engineer would be to have some basic understanding of aesthetics (look and feel) & documentation. How components are placed and how silk screen is important.
Once PCB design work is completed, along with manufacturing files, documentation need to be sent to the PCB manufacturer like guide lines, any notes, stack-up details, assembly sketches, drill details, etc.
When product itself is an electronics circuit board, board sketches with labeling of all connectors, jumpers, etc. is required so that user can understand and interface external boards or circuitry easily. See this video Robert has explained documentation for PCB Design really well.
Hope this helps. If you like the article, share with your friends so they can learn too.
Thanks for reading. Happy Learning to you!