Why Do We Keep Doing Things the Old Way? A Story of Nets Crossing Gaps.

By Kanchan Vaidya

Remember the old times when we used to have a dedicated person type up all our letters? For better or worse, those days are over. As engineers we’d rather minimize manual labor and have it done by machines. In fact, automation has changed everything around us: the way we make phone calls, how we write letters, and even how we drive cars.

So why do we keep inspecting our printed circuit boards manually? I have heard stories of my colleagues burning the midnight oil to review a board manually, layer by layer, to make sure that no basic rules of PCB design were violated in the final layout.

With the free edition of HyperLynx DRC, a computer can do the task for you, faster and with greater accuracy. The best example is when traces cross a gap in the plane. This is not a good design practice since it doesn’t provide a good return current path for the signal and can cause undesirable EMI radiations. Manually inspecting for this rule is especially tricky because we need to compare multiple layer at the same time.