Press-Fit Connector Assembly: Compliant Pins and Hole Fit A press-fit connector is attached to a board by forcing a compliant pin into a plated hole. There is no solder, no reflow and no thermal excursion, which is why the technology is used on thick backplanes where soldering would be difficult…

Solder Pot Alloy Analysis and Contamination Control A wave solder pot is not a static bath of metal. Every board that passes through it dissolves a little copper, every top-up adds alloy that may be slightly different from what is already there, and every hour at temperature changes the chemistry…

FPC Manufacturing: The Layers Inside a Flex Circuit A flexible circuit looks like a thin printed board, but its construction is a different stack of materials chosen for bending. Understanding the layers explains why a flex design cannot simply be a rigid design printed on a thinner substrate. What a…

Scanning Acoustic Microscopy for Package Delamination Some of the most damaging defects in a plastic package are invisible from the outside and completely transparent to X-ray. A thin layer of air between the mould compound and the die pad, or between a solder mask and a copper plane, changes almost…

SMD Aluminium Electrolytic Capacitor For Reflow A radial aluminium electrolytic capacitor is one of the last through hole components on many boards. It cannot be placed by a machine that expects a flat body with solderable pads, so it is inserted by hand, clinched, and soldered in a wave. That…

Power Thick Film Resistor With Thermal Monitoring A resistor that has to absorb a large amount of energy in a short time, or dissipate a continuous power that a chip resistor cannot handle, moves into a different class of package. The element is printed onto a ceramic substrate and housed…

SMT Assembly Process Overview: From Paste to Test A surface mount line is a sequence of machines that each do one thing well, and the quality of the finished assembly is decided by how well the steps agree with each other. Paste, placement and profile are one system rather than…

PCB Selective Wave Solder: From Design to Repeatable Production 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…

PCB Baking Before Assembly: From Design to Repeatable Production 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…

PCB Last Article Check: What Buyers and Engineers Should Check 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 last article check from the perspective of a PCBA…