Designing Hardware Boards Around a Mobile Applications Processor A mobile applications processor is a system on a chip with everything dense about board design in one package. It has multiple power domains that must come up in a defined order, high speed interfaces that behave like transmission lines, a memory…

Manufacturing Considerations for Large PCB Formats Boards grow for good reasons: a system that used to be split across several assemblies becomes one board, or a product needs a larger panel for a higher throughput of units. Both trends lead to formats that fall outside the range a shop handles…

High Speed Routing Requirements for PCB Layout High speed routing is not a separate technique from ordinary routing. It is the same activity with additional constraints that become significant once the rise time of the signal is short enough that the trace behaves as a transmission line rather than as…

PCB Routing Techniques That Improve Manufacturability A layout can be electrically correct and still be difficult to build. Manufacturability problems do not show up in a simulation, and they do not show up on the bench prototype, because the prototype was made with extra care. They show up in production,…

EMC Design Techniques for PCB Layout Electromagnetic compatibility is usually treated as a test that happens at the end, when the board is finished and the enclosure is closed. By then most of the outcome has already been decided, because emissions and immunity are properties of the layout, and the…

Perfboard Soldering: Tools, Five Steps and Good Joints Perfboard, also called dot matrix board or protoboard, is a sheet covered with pads on a standard 2.54 mm pitch that lets a circuit be assembled by inserting components and wiring them point to point. Compared with ordering a fabricated board, it…

Common PCB Design Mistakes and How to Avoid Them The electronics industry moves quickly, and the pressure to release a board early is one of the reasons design errors survive into production. Most of the common PCB design mistakes described here are not subtle. They are the ones that look…

High Current Path Planning on a PCB: Routing Strategy When a board has to deliver tens of amperes, the usual assumption that a trace is just a connection stops being adequate. A high current path has resistance, it produces heat, and the heat changes the resistance, so the design has…

FR-4 Material in PCB Construction and Its Applications Almost every rigid board in production is built on the same family of material, and understanding what that material is explains a great deal about the limits of the board: why it is stiff, why it is dimensionally stable in one direction…

PCB Baking Before SMT Assembly: Temperature and Time Rules A bare board that has been sitting in a warehouse is not ready for the reflow oven. Laminate and solder mask absorb water from the air, and when that water meets reflow temperature it turns to steam faster than it can…