Direct contact plating - Inline plating solution for ZEBRA IBC by local contacting

An inline plating solution, in which electrolyte and contact system are arranged on the same side, is presented in this work. This concept allows plating onto cell concepts that do not have existing seed metallization on a significant share of surface area, e.g. ZEBRA IBC solar cell. Local contacting of Si or local metal structures is required to enable plating on these cell concepts. A new contacting scheme, which includes a stainless steel brush, was adapted into the existing inline plating tool of the company RENA Technologies GmbH. It allows local contacting of Si and of metalstructures without any temporary masking. First results of a plated contact grid on a ZEBRA IBC solar cell are successfully demonstrated. One result presents the simultaneous plating of n-type BSF and p-type emitter with finger heights of 18 mm ± 2 mm and of 10 mm ± 1 mm, respectively. In addition, important process development steps such as alignment are shown. An edge inhomogeneity and simultaneous plating on both polarities could be solved by introducing an electroless Ni seed. Furthermore, a plating voltage limitation proved also to be beneficial for plating homogeneity. Adaptations in the inline plating tool were also made.