Solder Preforms and Pin-in-Paste Assembly The Problem A through-hole joint needs a fillet on both sides of the board to be mechanically sound, and the volume of solder that requires is far more than the paste that can be printed onto a pad at a normal stencil thickness. In a…

SMT Component Placement Repeatability: The Same Spot Every Time 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. The same…

Shield Can Assembly: Footprint and Solder The Can as an Assembly A shield can is a mechanical part that is also an electrical one, and getting it onto a board reliably is an assembly problem rather than a layout problem alone. The can is a large, thin, flat metal part…

PCB Via Temperature Cycling: Heating and Cooling the Hole 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 via temperature cycling from the perspective of a PCBA factory…

Humidity and Condensation Testing Why Humidity Is Tested Moisture is involved in a large share of field failures that are not mechanical: it accelerates corrosion, it enables electrochemical migration and conductive anodic filament growth, it changes the dielectric properties of the laminate, it degrades the adhesion between the materials, and…

Thermal Cycling Tests for Assemblies What Cycling Tests A thermal cycling test exposes an assembly to repeated changes in temperature and measures how long it survives. The mechanism it targets is the difference in expansion between the materials: the laminate, the copper, the solder and the component package all expand…

SMT Reflow Solder Paste Shelf Life: How Long the Paste Lasts 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 SMT reflow solder paste shelf life from the perspective…

Surge and ESD Protection Layout Two Different Threats Electrostatic discharge and surge are different events with different energies and different timescales, and a protection design has to account for both. An electrostatic discharge is a short, fast event with a rise time measured in hundreds of picoseconds and a current…

PCB Copper Trace Chemical Resistance: How the Copper Handles Chemicals 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…

EMC Filters on the Board: Layout and Return What a Filter Has To Do A filter on a board is there to keep noise from leaving through a cable, or to keep noise from entering a circuit from outside. It works by presenting a high impedance to the noise while…