Challenges of Cooling Compact Devices  

Small-size DC blower fans (≤60mm) are critical for:  

Gaming Laptops: Cooling RTX 4060 GPUs in sub-20mm thick chassis (e.g., ASUS Zephyrus G14).  

Mini-PCs: Intel NUC and Raspberry Pi 5 with limited space for heat sinks.  

Aerospace Electronics: Avionics in drones and satellites with strict size constraints.  

Miniaturization Technologies  

Micro-Bearing Systems: 3mm hybrid ceramic bearings (e.g., C&U Group) enable 10,000 RPM in 20mm fans with 0.001 Nm friction.  

Axial-Flow Design: Curved blades (15–22° pitch) maximize airflow (0.5–3.0 CFM) in 20–60mm form factors.  

Flexible Electronics: Flat flex cables and solderless connectors reduce space requirements by 30%.  

Top Small-Size Fan Models  

Nidec-Sankyo UF04010HA:  

  Specs: 40x40x10mm, 0.8 CFM, 22 dB, 12V, ceramic sleeve bearing, used in DJI Avata drone for flight controller cooling.  

Sunon MagLev MicroFan:  

  Specs: 15x15x2mm, 0.1 CFM, 15 dB, 5V, magnetic levitation, world’s smallest BLDC fan for hearing aids.  

ARCTIC P8 Slim:  

  Specs: 80x80x15mm, 22 CFM, 18 dB, 12V, low-profile design for Intel NUC 13 Pro.  

Thermal Management Strategies  

Stacked Cooling: Combine a small fan with a heat pipe and vapor chamber (e.g., Razer Blade 14 uses a 60mm fan + vapor chamber for Ryzen 9 7940HS).  

Active-Passive Hybrid: Fan runs only when passive cooling (heat sink alone) exceeds 60°C, reducing noise by 50% during light use.  

Airflow Ducting: 3D-printed ducts (e.g., PETG material) direct 100% of fan airflow to hotspots like CPU dies in mini-PCs.  

Material and Reliability Trends  

Liquid Crystal Polymer (LCP) Impellers: Gdstime’s 30mm fan uses LCP for heat resistance (280°C) and low weight (0.5g).  

Hermetic Sealing: IP67-rated small fans (e.g., Delta BFB0605H) for outdoor IoT sensors, with welded aluminum frames to prevent water ingress.  

Testing and Validation  

Altitude Testing: Small fans for drones must maintain 80% airflow at 5,000 meters (e.g., Sunon’s AeroCool series with altitude compensation).  

Shock Resistance: Meets MIL-STD-810G for 50g shocks (e.g., Nidec’s UF series in military-grade tablets).