Practical Notes on Dross Formation Wave soldering is a process of thermal balance rather than of fixed settings. The solder pot, the preheaters, the fluxer and the conveyor interact, and a change in any one of them shows up somewhere else. Two symptoms dominate production problems: joints that do not…

Practical Notes on LCD TV PCB Television hardware looks simple from the outside and is dense on the inside. A modern set combines a power supply, a video processor, several high-speed input interfaces and a panel driver, and most of them share a single board. LCD TV PCB assembly therefore…

High Layer Count PCB Fabrication: Sampling to Volume Once a board passes roughly twenty layers, the process stops being a scaled-up version of an ordinary multilayer build. Boards used in AI accelerators, 800G switch fabrics and communication backplanes now run from 20 layers to 80, with finished thickness between 2 mm…

PCB Schematic vs PCB Design File: Key Differences Schematic and design file are often used as if they described the same thing, and newcomers to board work frequently treat them as interchangeable. They are not. One is a logical plan of what connects to what; the other is a physical…

PCB Stackup Design: Principles for Multilayer Boards PCB stackup design is the least glamorous document in a hardware project and one of the most consequential. It fixes the distance between every pair of layers, decides which copper is a reference plane, and determines whether the impedance numbers in the layout…

Insulated Metal Substrate PCB: Thermal Design Basics An insulated metal substrate PCB is a board in which the usual glass-reinforced laminate is replaced by a metal plate, normally aluminium, covered by a thin dielectric layer and a copper circuit. The metal does not carry current; it carries heat. Because the…

PCB Design Workflow: Requirements, Placement and Prototyping A board design that goes smoothly is usually one where the early steps were taken in the right order. Requirements, the system design, the component choices and the schematic all constrain what the layout can achieve, and a layout that starts before those…

PCB Short Circuit Prevention: Design and Assembly Practices A short circuit is the defect that wastes the most time in the assembly and bring-up phase, because it can damage parts before anyone notices it exists. Finding one after the fact is slow: the board may have hundreds of nets and…

Alarm Panel PCB Design: Zones, Backup Power and Tamper An alarm panel PCB has to work when everything else has failed. It runs on mains with a standby battery, it monitors a set of loops that may be kilometres of wire, it drives a siren that draws several amperes, and…

Thermostat PCB Design: Sensing, Load Switching and Power A thermostat PCB has an unusually wide set of responsibilities. It measures temperature accurately, decides what the heating or cooling equipment should do, switches loads that may be mains powered, runs for years on a battery or on a few hundred microwatts…