Layout Techniques That Improve Manufacturability Manufacturability is not a separate review that happens after the layout is finished. It is a set of layout techniques that are applied while the board is being designed, and each of them either prevents a problem or moves it to a stage where it…

Through, Blind and Buried Vias: Choosing a Construction A via is a drilled hole with metal plated onto its wall, and its only job is to connect copper on one layer to copper on another. The three types differ in where the hole starts and stops, and that difference decides…

Thermal Relief and Copper Balance in PCB Design Two decisions about copper are made on almost every board and are almost never written down. The first is how a pad is connected to the plane around it, which decides how easily the joint can be soldered. The second is how…

Unintended Capacitance and Coupling in a PCB Layout Every pair of conductors on a board has capacitance between them, whether the designer intended it or not. Most of the time the value is small enough to ignore; when it is not, the effect appears as a slower edge, a coupled…

Flexible Polyimide Cost: High-Temperature Circuit Pricing Polyimide is the substrate of last resort on a cost sheet and the first choice on an environmental one. When a board has to survive 260 degrees Celsius, bend around a housing, resist solvents and keep working for a decade, the material stops being…

High Density Layout: Escape Routing and Fanout for Dense Boards Density is what forces a layout to become clever. When a device has more pins than the space around it can escape, the routing must go through the board rather than around the package, and every decision about vias, layers…

Computer PCB Price Guide: Motherboard, GPU and Server Boards Almost every product with a processor contains a computer board, and the price range across that family is enormous. A simple control board with two layers and a microcontroller sits at the bottom, while a server motherboard with twelve layers and…

Hard Drive PCB: Signal Integrity, Motor Drive and Power A hard drive PCB is unusual among circuit boards because it combines three very different functions on a small piece of laminate that sits on the underside of a mechanical assembly. It has to run a precision analogue read channel, drive…

High Frequency PCB in Mobile Devices: Materials and Layout A modern phone or watch contains more radio frequency circuitry than a laboratory instrument did a generation ago, and almost all of it sits on the main board rather than in a separate module. The consequence is that the high frequency…

PCB Panelisation: V-Cut, Stamp Holes and Spacing Very few boards are built one at a time. Several copies, or several different designs, are combined into a panel so that the fabricator and the assembly line handle one object instead of many, and the way they are joined decides both the…