Can Seamer Control Board Design for Industrial Use A can seamer is an industrial machine that closes a lid onto a filled container with a pair of rotating rollers, and its control board has to coordinate several motors, read a set of position sensors and stop instantly when a guard…

Portable Fan Circuit Design: Motor, Battery and Noise A portable fan is a battery, a small brushless motor and a charging input in a housing that the user holds. The electronics are simple, and almost every design decision is about noise, run time and cost. What the Product Does The…

Charging Pile Control Board Design for Outdoor Use A shared charging pile is a networked power outlet with a meter, a payment interface and a safety chain. Its control board has to be robust, because it is installed outdoors and expected to run for years without attention. What the Control…

Second Side Reflow and Component Retention Methods When a board has components on both sides, the second pass through the oven heats parts that are already attached and upside down. Some of them stay in place because the molten solder holds them, and some do not. Understanding which category a…

Potting and Encapsulation of PCB Assemblies Potting and encapsulation surround the assembly with a material that protects it from moisture, contamination and mechanical damage. They also change the thermal path, the serviceability and the stresses on the components, and none of those effects is reversible. What Encapsulation Buys The material…

Moisture Sensitivity Levels and Floor Life Control A sealed bag of components carries more information than most people read. The label states a moisture sensitivity level, and that number quietly defines how long the parts may sit on the factory floor before they must be dried again. Ignore it and…

Percussion Massager Drive Design and Power Budget A percussion massager drives a small motor back and forth against a spring, and the electronics have to deliver a controlled amount of energy per stroke from a battery while keeping the pressure on a muscle rather than on a joint. What the…

Vibration and Shock Design for PCB Assemblies A product that is transported, mounted in a vehicle or used on machinery will see vibration and shock, and the assembly is usually the part that is designed last for it. The failures that follow are not random: a heavy part on a…

Depaneling: Preparation, Placement and Process Control A panel exists so that the assembly line has something large enough to handle, and the boards have to be separated again before the product is finished. The separation step is where a surprising amount of damage is done, because the operation that breaks…

Silver Migration and Electrochemical Failure Paths A board that passes every test in a dry factory can fail in a humid enclosure with no component having degraded at all. The culprit is often an invisible conductive path that grew between two conductors over weeks or months, fed by moisture, contamination…