Surface Tension and Viscosity in Solder Wetting Solder does not flow because it is pushed; it flows because the forces around it are balanced in its favour. Surface tension acts to minimise the free surface of the liquid, and viscosity resists the movement of the liquid itself. Both work against…

EMC Immunity Testing: Radiated Field Susceptibility Immunity is the other half of electromagnetic compatibility, and it is usually the harder half to test. Emissions can be measured without touching the product; immunity requires the product to be operating normally while a disturbance is applied, and the failure may be a…

PCB Layout for Soldering: Design Choices That Decide Yield Most soldering defects are not created at the soldering station. They are created by a pad that is too wide, a via placed in the middle of a pad, a fiducial that the vision system cannot see, or a component rotated…

PCB New Operator Onboarding: The First Weeks 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…

PCB Failure Analysis Flow: Working Back to the Cause 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 failure analysis flow from the perspective of a PCBA factory…

PCB Size and Shape Requirements: Defining the Board Outline A printed circuit board has to fit the application it was designed for, and the application dictates the size and the shape. That sounds obvious, yet the outline is often the last thing to be finalised and the first thing to…

Aluminum PCB Advantages and Applications Most boards are built on a laminate chosen for its electrical properties, and the heat has to be carried away by copper and by air. An aluminum PCB reverses that priority. The substrate is a metal plate, and the board is designed around getting heat…

Depth-Controlled Milling on PCB Panels: Holding Z Tolerance Some boards cannot be profiled with a through-cut. Where a recess has to be milled to a controlled depth, or where a cavity must stop a fraction of a millimetre above an inner layer, the routing depth becomes a process parameter in…

Mobile Phone PCB Layout: Layer Plan and Routing Order A handset main board packs a radio, a baseband processor, memory, power conversion and a display interface into a space smaller than a business card. The mobile phone PCB layout that makes this possible is not a single clever trick but…

Aerospace PCB Assembly: Designing for the Space Environment Aerospace electronics are not simply rugged versions of industrial hardware. The environment is different in kind: radiation that can corrupt logic, temperature swings of hundreds of degrees, vibration and shock during launch, and a service life during which no repair is possible.…