1. Product Overview
REL61™ is a lead-free solder alloy developed by AIM, composed of tin, bismuth, silver, copper, and grain structure refiners. It provides a cost-effective alternative to SAC alloys while delivering performance equal to SAC305 and superior to other low/no-silver alloys. REL61 reduces tin whisker formation and demonstrates enhanced resistance to thermal shock, vibration, and drop shock. Its lower reflow and solder pot temperature requirements make it highly efficient for lead-free soldering processes. The alloy complies with IPC J-STD-006 standards.
2. Applications
REL61 is designed exclusively for lead-free soldering processes and is widely applicable in electronics assembly. It is available in bar form, solid feeder wire, and no-clean solder paste. Its robust mechanical and thermal properties make it suitable for demanding environments where reliability, durability, and cost efficiency are critical.
3. Typical Properties – Specifications
- Alloy Composition: Sn with Bi, Ag, Cu refiners
- Melting Range: 208–215°C (lower than SAC305’s 217–220°C)
- Density: 7.38 g/cm³
- Wetting Time: 0.9 sec (same as SAC305)
- Wetting Force: 4.4 mN (same as SAC305)
- Hardness: 26 HV10 (vs. 14 HV10 for SAC305)
- Thermal Conductivity: 65 W/m·K (higher than SAC305’s 58 W/m·K)
- Coefficient of Thermal Expansion (CTE): 25.49 ppm/°C (vs. 21.0 ppm/°C for SAC305)
- Electrical Resistivity: 0.156 µΩ·m
- Electrical Conductivity (IACS): 11% (vs. 16.6% for SAC305)
- Tensile Strength (aged 150°C for 24 hrs): 70 MPa (vs. 34 MPa for SAC305)
- Elastic Modulus @ 23°C: 54 GPa
- Yield Strength @ 23°C: 56 MPa
- Shelf Life: 7 years under proper storage conditions
- Availability: 1.1 kg bars, 3.175 mm feeder wire, and M8 T4 500 g no-clean solder paste (other options on request)
- Safety: Requires adequate ventilation and protective equipment; disposal must follow approved hazardous waste protocols.