Teardrop (electronics)

Teardrops as seen in a PCB layout design tool

In printed circuit boards, a teardrops are typically drop-shaped features at the junction of vias or contact pads and traces.

The main purpose of teardrops is to enhance structural integrity in presence of thermal or mechanical stresses.[1] Structural integrity may be compromised, e.g., by misalignment during drilling, so that too much copper may be removed by the drill hole in the area where a trace connects to the pad or via.[2] An extra advantage is the enlarging of manufacturing tolerances, making manufacturing easier and cheaper.[3]

While a typical shape of a teardrop is straight-line tapering, they may be concave.[2] To produce a "snowman"-shaped teardrop, a secondary pad of smaller size is added at the junction overlapping with the primary pad (hence the nickname).[4]

References

  1. ↑ "Component placement tips and strategies", EDN Network
  2. 1 2 "Enhanced Teardrop Control", Altium Designer technical documentation
  3. ↑ "Why Where When and how teardrops should be added to PCB? ", Kaizen Technologies
  4. ↑ "PCB Design Guidelines for 0.5mm Package-on-Package Applications Processor, Part I", Texas Instruments, Application Report SPRABB3, June 2010 (retrieved July 27, 2015)
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