Rubycon Corporation SMD Capacitors

SMD aluminum electrolytic capacitors are used in space-constrained electronic applications where through-hole mounting is not feasible. Common applications include consumer electronics (TVs, monitors, audio equipment), portable devices, LED drivers, and high-density industrial controls. They provide higher capacitance values than ceramic capacitors of equivalent size, making them ideal for power supply filtering, bulk decoupling, and energy storage in compact designs. The surface-mount construction enables automated pick-and-place assembly, reducing manufacturing costs. SMD capacitors are particularly useful in applications requiring capacitance above 10uF where ceramic capacitors would be too large or expensive.

Use SMD capacitors for space-constrained designs requiring high capacitance and automated assembly.

SMD and radial lead capacitors differ in mounting method and typical applications. SMD capacitors mount directly to the PCB surface using reflow soldering, enabling automated assembly and higher PCB density. Radial lead capacitors have wire leads that pass through PCB holes and are wave or hand soldered. SMD capacitors are generally smaller and more compact but have lower capacitance and voltage ratings than equivalent-sized radial capacitors. The lifetime and ripple current ratings are typically lower for SMD types due to size constraints. SMD capacitors are preferred for high-volume consumer electronics, while radial lead capacitors are better for industrial applications requiring higher reliability and easier field replacement.

Select SMD for high-volume automated assembly; radial lead for industrial reliability and serviceability.

Rubycon SMD capacitors should be soldered using standard lead-free reflow profiles per JEDEC J-STD-020. Typical profile: preheat to 150-180C over 60-120 seconds, ramp to peak temperature of 245-260C, time above 217C limited to 60-90 seconds, peak temperature duration of 20-40 seconds. Maximum peak temperature should not exceed 260C. The capacitor terminals should have adequate solder paste coverage for reliable joints. Nitrogen atmosphere can improve solder joint quality. Avoid rapid cooling which can cause thermal shock. For double-sided assembly, capacitors can withstand two reflow cycles. Always follow Rubycon's specific datasheet recommendations for the series being used.

Follow JEDEC J-STD-020 profile with peak temperature not exceeding 260C.

SMD aluminum electrolytic capacitors are available in case sizes from 4mm x 4mm to 10mm x 10mm diameter, with heights from 5mm to 13mm. The maximum capacitance is typically limited to around 1000uF at low voltages, decreasing at higher voltages. Voltage ratings are generally limited to 50V maximum. These limitations are due to the physical constraints of surface-mount construction and the need for reflow compatibility. For applications requiring higher capacitance, voltage, or ripple current, radial lead or snap-in capacitors are more appropriate. Within the SMD category, larger case sizes provide higher capacitance and better ripple current capability but require more PCB area.

Select largest case size that fits your PCB for maximum capacitance and performance.

Rubycon SMD capacitors are available with 105C temperature rating, making them suitable for many high-temperature applications. However, the lifetime at 105C is typically 2000-5000 hours, shorter than equivalent radial lead capacitors due to size constraints. For applications with sustained high temperatures, proper derating is essential. Operating at 85C instead of 105C can extend lifetime by 4x. The compact size of SMD capacitors means they have less thermal mass and can heat up more quickly from ripple current. Ensure adequate PCB copper area for heat dissipation and avoid placing near other heat-generating components. For extreme temperature applications, consider radial lead alternatives.

Use 105C rated SMD capacitors with proper thermal management for high-temperature applications.