PCB Castellated Edge Design: Holes Cut in Half Electronics manufacturing has become a discipline of small details. Solder paste volumes, placement accuracy, temperature profiles and inspection limits all add up to the final result. This guide looks at PCB castellated edge design from the perspective of a PCBA factory floor,…

FR4 Versus Rogers Versus Aluminium Substrates Most boards are built on FR4 because it is cheap, well understood and available in every shop. As soon as the frequency rises or the power density increases, that choice becomes a compromise, and two alternatives appear: a low loss laminate such as Rogers,…

LVDS Clock Buffer Layout And Termination Practice A clock buffer that distributes one reference to four or more loads is judged by two numbers that a schematic cannot show: how much jitter it adds, and how far apart the outputs drift from each other. Both are decided largely by the…

Four Layer Metal Core Board Stack Options A metal core board is chosen for one reason: heat has to leave the components through the back of the board. The simplest version of the structure carries a single copper layer on a thin dielectric over an aluminium plate, and for many…

Thermal Interface Material Thickness and Contact Resistance The thermal path from a hot component to a heatsink or chassis is only as good as the interface between them. Two flat surfaces that look smooth in the hand touch at a small number of high points, and the air trapped in…

PCB Flex Coverlay Openings: Windows in the Cover Modern electronics depend on boards that are assembled correctly the first time. Every product – a phone, a charger, a medical instrument or an industrial controller – relies on thousands of solder joints that must conduct current for years. This article explains…

PCB Dynamic Flex Life: Bending Again and Again Buyers and engineers often focus on the finished product and forget the production line behind it. In practice, most field failures can be traced back to process decisions made during assembly. Understanding PCB dynamic flex life gives you a practical advantage when…

Common Mode Choke Selection for Signal and Power Lines A common mode choke presents a high impedance to the current that flows in the same direction on both conductors and a low impedance to the signal. Its selection is usually made on the impedance figure alone, which is the least…

Procurement Documentation: Specifications, Drawings and Supplier Dialogue Most disagreements between a customer and a fabricator come from a document that is incomplete rather than from a process that is incapable. The specification is the interface, and it is worth more attention than it usually receives. What the Fabrication Drawing Must…

PCB Downtime Record: Naming the Stops Modern electronics depend on boards that are assembled correctly the first time. Every product – a phone, a charger, a medical instrument or an industrial controller – relies on thousands of solder joints that must conduct current for years. This article explains PCB downtime…