Solder Wick and Rework Tools: Selection and Control Solder wick is a braid of fine copper strands that removes molten solder from a joint by capillary action. It is the simplest desoldering tool in a rework station and the one that causes the most damage when it is used badly,…

Assembly Traceability Data Structure and Retention Traceability is a data structure rather than a mark. The mark identifies the unit, and the structure decides what can be asked of it afterwards, which is the part that determines whether a field problem can be narrowed to a day or to a…

Automatic Optical Inspection Programming in Production An automatic optical inspection system is only as good as the program it runs, and the program is built from CAD data, a component library and a set of thresholds that decide what is acceptable. Programming is therefore where the inspection yield, the false…

Wave Soldering: Design Rules and Process Limits Wave soldering is a mature process that still produces a characteristic set of defects: bridging between adjacent pins, icicles and webs, insufficient fill in a plated through hole, solder balls and a dull, grainy surface that suggests the alloy or the flux has…

Second Side Reflow and Support Fixture Design Guide On a double sided assembly the second reflow pass is the one that causes trouble, because the components placed on the first side are now on the underside and held only by the surface tension of their own solder joints. Second side…

Selective Soldering: Design Rules and Process Limits Selective soldering fills through holes one joint at a time with a small nozzle, which makes it the natural choice for mixed technology boards where wave soldering would damage the surface mount side or where only a few through-hole parts remain. The process…

Flux-Cored Solder Wire Selection for Hand Soldering Hand soldering is judged by the joint it produces, and the wire used to make it is as much a process material as the paste used in reflow. A flux-cored solder wire combines the alloy and the flux in one consumable, and the…

ESD Control in Electronics Assembly Electrostatic discharge is invisible, intermittent and capable of reducing the life of a component without producing any immediate measurable change. A board damaged by a discharge may pass every test on the line and fail in the field months later, which makes the cost of…

Conductive Adhesive Assembly in Electronics Manufacturing Conductive adhesive joins and conducts with a polymer rather than with a molten alloy. It is chosen when the temperature required for soldering is the problem: a component that cannot survive reflow, a substrate that is not solderable, a heat sensitive structure or a…

Tape and Reel Packaging Requirements for Automated Assembly A component that is packed badly cannot be placed well. Tape and reel packaging is a mechanical interface between the component supplier and the placement machine, and it determines whether the part arrives at the pickup position reliably or intermittently. Most packaging…