Enhancement of the Surface Smoothness of Cu Ribbon for Solar Cell Modules

We studied the relationship between the surface smoothness of the internal Cu ribbon and the morphology of theSn-Pb plating layer for solar cell modules. A bumpy surface was observed on the surface of the solar ribbon, whichcaused irregular reflection of light. Large, Pb-rich, primary α-phases were found below the convex surface of the solarribbon, passing from the surface of the internal Cu ribbon to the surface of the plating layer. The primary α-phasesheterogeneously nucleated on the convex surface of the Cu ribbon, and then largely grew to the convex surface of theplating layer. The restriction of the primary α-phase's formation was enabled by enhancing the smoothness of the Curibbon's surface; it was also possible to increase the adhesive strength and decrease contact resistance. We confirmedthat the solar ribbon's surface smoothness depends on the internal Cu ribbon's surface smoothness. KCI Citation Count: 2