5 Basic Steps to a Successful PCB Layout - Part 1
Stilwell Baker is our favorite PCB design company in the Northwest. They provide PCB layout, Library Management, DfX engineering and Component engineering. With 20 or more designers and many years in the business, they have a wealth of experience. Joe Zaccari and the team at Stilwell Baker have generously offered to share some of that expertise in a five-part blog post.
Today, he's starting with advice on parts libraries. Check back weekly for the next four parts of the series:
- Know your library (today)
- Mechanical constraints matter
- Be careful with layer count
- Know your PCB fabricator
- Know your assembler
Taking the time to review a design prior to layout and resolve issues early results in lower costs and faster time to market. No rocket science here, just the old, “Find time to do it right the first time, not time (and $$$) to do it over”, lesson rearing it’s ugly head again. Many times PCB layout becomes the sponge that absorbs all of the schedule slips in the R&D process. Unfortunately, a great design, laid out poorly can be lethal to a product.
Know your Library: Part libraries are the single biggest source of problems with PCB layout.
- Part symbols on the schematic and part footprints in the Layout need to be verified and checked somewhere in your library process. Without this check, a defective part may find its way on to more designs before it is actually physicalized and tested. These types of part defects can be as simple as a not having the correct polarity to having the schematic symbol referencing the wrong footprint. Some defects will be easy to see when the part is being assembled, while others won’t appear until after some hair pulling and a few hours on the lab bench.
- Try to stick with industry standard part package types when possible. This will help the designer, fabricator, and the assembler. Trying to figure out how to create a footprint for something special and then trying to get it fabricated and assembled, may not be the best idea for designs on the fast track to market or near the production phase of your R&D.
- If you need to get creative and use a new part type or technology. It may be advantageous to include the fabricator and assembler along with your layout resource early on in the design process.
Next week: Mechanical constraints.