Effects of plating conditions on electroless Ni-P plating in the microchannel

Controlled flow electroless Ni-P plating in microchannel has been shown to provide a route for low-temperature and pressureless Cu-to-Cu interconnections [1]. However, it is found that operating temperature, flow rate, and local flow field would affect plating result. Operating temperature is related to the activity of the plating bath, and raising the operating temperature would promote electroless Ni-P plating. Flow rate determines the time during which the plating bath passes through the test vehicle. Increasing flow rate would increase the unplated area. Local flow field is determined by flow rate and the geometry of the Cu pattern in the microchannel. Low-flow velocity region tends to have the higher plating rate while high-flow velocity region tends to have lower plating rate.