"Copper core balls" generally refer to spherical solder components with a copper core used in electronic packaging. They consist of a pure copper core and a surface plating (such as tin alloy, nickel, etc.) forming a spherical structure used for high-reliability electronic interconnects, such as BGA (Ball Grid Array) and CSP (Chip Scale Package).
The working principle of copper core balls in 3D packaging is based on their multi-layer structure and material synergy. The high-melting-point copper core maintains thermal stability, exhibits excellent electrical and thermal conductivity, and demonstrates superior mechanical reliability during multiple reflows. It is a core supporting technology for achieving high-density stacking.
Structural Principle: A core of highly conductive, highly thermally conductive, and high-strength pure copper is used, with an outer layer plated with a solderable material (such as tin-silver copper SAC305), combining the mechanical stability of copper with the excellent solderability of the plating.
