Tombstoning Trouble
TechnologyThursday meets Halloween: The Tombstoning Effect in SMD Components 
Happy Halloween to all PCB enthusiasts and PCB designers!What could be more fitting on this spooky day than a phenomenon that makes tiny components stand up as if moved by a ghostly hand?
We’re talking about the tombstoning. In PCB assembly, this term refers to the one-sided uprighting of small or lightweight two-pole SMD parts during the soldering process. These then resemble tombstones in an old cemetery. The result: the lifted side of the part has no electrical contact and the circuit is open.
How does tombstoning happen? Not by magic, of course, but by physics. The surface tension of the molten solder on a solder pad attracts the part and can raise it up to 90° from the opposite solder pad.
How can the ‘tombstone effect’ be avoided? In addition to the soldering process, the PCB layout, the geometry of the connection pads, placement of the components, vias or labelling have a major influence on this soldering defect.
To ensure that tombstoning remains just a Halloween joke, here is our guide with useful tips and a video for production-orientated design: https://www.eurocircuits.com/pcb-assembly…/tombstoning/
English (UK)