When selecting copper strip wrapped solder posts, key considerations include material composition, structural parameters, process compatibility, and environmental tolerance. Especially in high-reliability applications such as aerospace and military, priority should be given to products with copper strip reinforcement, eutectic solder coating, and proven thermal cycling and vibration testing capabilities.
Main Post Material: 80Pb/20Sn solder posts are preferred, as their ductility and thermal fatigue life are superior to 90Pb/10Sn.
Reinforcement Structure: The outer layer should be 0.051mm thick copper foil wrapped around the post and completely covered with 63Sn/37Pb eutectic solder. This structure significantly improves shear resistance and thermal conductivity.
Size Specifications: Standard models are Φ19×19mm or Φ12.7×25.4mm. For high-density packaging, it is necessary to confirm whether custom miniaturization is supported.
Reflow Soldering Parameter Matching: Based on post-mounting process research, the optimal combination is: solder post inner diameter 0.40mm, post height 3.81mm, solder paste thickness 30μm, and cooling rate 2.0℃/s. When purchasing, request reflow profile recommendations from the supplier.
Solder Paste Type Matching: It is recommended to use a low-oxygen, high-activity no-clean solder paste to avoid solder voids or poor wetting.
Second Reflow Tolerance: Confirm that the product can withstand at least two reflow soldering cycles (peak temperature ≤220℃) to avoid solder joint degradation during encapsulation.
Thermal Cycling Performance: Must pass over 500 cycles of testing from -65℃ to +125℃, with no cracks in the solder joints and shear strength attenuation <15%.
Vibration and Shock Testing: Must comply with GJB548B-2005 Method 2003/2004 standard, with no connection failure under 20G acceleration.
Long-Term Storage Stability: The surface eutectic solder should have an anti-oxidation coating to ensure good solderability for 6 months.
