Issue link: https://iconnect007.uberflip.com/i/1327102
80 DESIGN007 MAGAZINE I JANUARY 2021 "Will my parts fit on the board?" That seems like it should be a rhetorical question that needs no answer, but reality tells us, as you transition from the design stage to manufac- turing, issues with parts fit are one of the most frequent causes of delays and cost overruns. We see it every day. Designs are submit- ted that can't or shouldn't be manufactured because the parts will not fit properly. This creates issues with performance and durabil- ity—effectively reducing the overall quality of the board. Following are six methods that will help you avoid common, parts-related manufacturabil- ity pitfalls. 1. Avoid pinhole pitfalls. It's important to check component physical dimensions. Height is an often-overlooked por- tion and can create issues at or after assembly. Take dimensional tolerances into consideration and account for variation that can impact fit. Through-hole pins can be the wrong size or have the wrong spacing, and components can actually be much larger than their footprint or land pattern might indicate. Surface mount parts take the pin diameter and tolerance out of the equation, making them easier to verify. It is far easier to take the time up front and be right than to have to re-spin a design or try to find an alternate part that fits your board. 2. What to do when the land pattern and pin size differ. One of the most frustrating mistakes with through-hole parts is when the land pattern matches, but the pin size is too large to fit reliably. Six Design Tips to Avoid Part Fit Problems Connect the Dots by Bob Tise and Matt Stevenson, TEAM SUNSTONE CIRCUITS