Field Returns: Diagnosis and Failure Classification A returned unit is the only evidence about how the product behaves in the field. Handling it as a repair job rather than as an investigation wastes the information it carries. The Return Process Begins Before the Unit Arrives The information accompanying the unit…

Depaneling Methods Compared: Router, Laser and Punch Most boards are built as part of a panel so that the assembly equipment has something to handle, and at some point that panel has to be divided into single boards. How it is divided decides how much mechanical stress reaches the solder…

High Current Connections: Busbars, Terminals and Heavy Copper Above a certain current, a trace on a board is the wrong conductor. A busbar, a terminal or a heavy copper layer is the answer, and each brings its own mechanical and thermal requirements. Where the Trace Stops Working A trace becomes…

System Level PCB Design in the Modern Project A modern board project mixes hardware and software, several power domains and a radio, and the design decisions are made before either discipline has finished. The layout has become the place where those decisions are reconciled rather than the last step of…

High Frequency Board Fabrication: Working With PTFE A high frequency laminate behaves differently on the production line from the epoxy material the shop runs every day. It is softer, it expands more with temperature, and it does not accept the same drilling, plating and mask processes without changes to the…

Wearable Device PCB Design: Materials and Antennas A wearable is a radio, a battery, a sensor and a processor inside something the size of a wristband, and the board has to survive being worn. There is no established standard for that combination, so the design decisions come from the physics…

Conformal Coating Repair After Rework Rework after conformal coating is a normal part of production and a common source of field failures. The coating must be removed to reach the joint, and the repair must restore the protection the design assumed. Why Coating Repair Matters The coating is usually the…

PCB Inspection Before Assembly: What to Check Most of the cost of a bad build is committed before the first panel is etched. Checking the data package, the placement and the routing before the order is placed costs an afternoon and prevents the failure modes that a re-spin cannot recover…

AOI Programming: Reference Images, Tuning and False Calls An automated optical inspection system is only as good as the program driving it. A program built from a golden board and never tuned produces a stream of false calls, and a false call is worse than no inspection because it consumes…

Solder Paste Printing on Flexible Substrates Printing paste onto a flexible substrate is the same process as printing onto a rigid board and it behaves differently in every detail. The material moves, the carrier decides the flatness and the stencil release depends on the support underneath. Why the Substrate Matters…