Issue link: https://iconnect007.uberflip.com/i/1520701
54 DESIGN007 MAGAZINE I MAY 2024 Engineering is both an art and a science. e design engineer's task is (almost) always to bring product to market that meets specifi- cations at the best and most economical price suited to the appropriate end use requirements. From a PCB perspective, designers are faced with a bewildering and almost overwhelming choice of materials at their disposal. Design Focused to Minimise Costs Small is beautiful in every respect, especially when it comes to high speed and high reliabil- ity. First, put the spotlight on: Short: By keeping high-speed traces as short as possible, the risk of signal reflections causing problems can be minimized. PCB traces always operate as transmission lines, but if the length is kept short com- pared with signal rise time, their effects are benign. Likewise, at higher speeds, when copper and dielectric losses become sig- nificant, the nature of these losses is proportional to trace length, so if you can arrange a design to halve the length of the high- speed serial busses, then you halve the losses. is may enable you to adopt a more economi- cal base material or a more standard copper sur- face. Slim: By this, I mean minimizing the Z-axis height. A low layer count board and a thinner board will yield better thermal reliability and will minimise the length of vias and avoid the need for backdrilling those troublesome via stubs. While on the subject of avoid- ing stubs, I recall Dr. Eric Boga- tin once mentioning that it might be a better route to take a critical signal using a conventional via from top to bottom of the PCB and then back up to use two vias with minimum stub length when transitioning the trace one or two layers where backdrilling is not Overconstraining: Short, Slim, and Smooth The Pulse Feature Column by Martyn Gaudion, POLAR INSTRUMENTS