There are 3 types of SMD capacitors.
Ceramic capacitors are non-polarized components.
Tantalum capacitors and aluminum electrolytic capacitors have polarity. Their positive electrode should be placed in the same direction as the PCB pad's positive electrode.
SMD tantalum capacitor polarity identification
SMD tantalum capacitors are polarized components. For tantalum capacitors, the polarity is marked by:
- 1. The positive electrodes of the PCB and tantalum capacitor are both marked by a color strip.
- 2. The positive electrodes of the PCB and tantalum capacitor are both marked by a "+" symbol.
- 3. The positive electrode of the PCB pad is marked by a bevel.
Aluminum electrolytic capacitor polarity identification
For aluminum electrolytic capacitors, the polarity is marked by:
- 1. The negative electrode of the aluminum electrolytic capacitor is marked by a color strip or block. Therefore, the opposite side is the positive electrode.
- 2. The positive electrode of the PCB pad is marked by a color strip.
- 3. The positive electrode of the PCB pad is marked by a "+" symbol.