What is SMD Polarity?
Polarity means the direction of SMD components when soldering on printed circuit boards. SMD polarity has two meanings as below:
1. For LEDs, diodes, tantalum capacitors, and so on, polarity means the active/negative electrode of the component is in the same direction as the PCB's active/negative electrode mark.
2. For ICs (including BGAs), and multi-pin inductors, polarity means the component's first pin/ball is in the same direction as the PCB's first-pin mark.
If the SMD polarity is reversed on the circuit board, the whole PCBA will fail. That's why both engineers and PCBA manufacturers should be aware of the SMD polarity identification.