Influence of Rare Earth on the Peeling Properties of Ultra-Thin Copper Foil with Carrier

Abstract

In this paper, the peeling strength between ultra-thin copper foil and carrier is improved by some rare earths used as additives during the formation of the stripping layer of H-G alloy. The effect of different rare earth and their different contents on the stripping property of ultra-thin copper foil with carrier when they are added in the H-G plating solution is investigated, and the influence of rare earth on the cathodic polarization curves and cyclic voltammetry curves of H-G alloy during its electrodeposition is analyzed too. Results show that rare earth elements of La, Sm, Y and Ce increase the peeling strength between ultra-thin copper foil and carrier to a certain extent and the peeling strength is increased from 0.13 kgf •cm-1 to the range of 0.16 ~ 0.20 kgf •cm-1. Different rare earth contents also have impact on the peel strength and surface property of ultra-thin copper foil with a carrier support, in which the optimum adding amount of La is 0.1 g •L-1. Electrochemical test results show that the addition of rare earths can reduce the degree of the plating solution’s polarization, accelerate the electrode reaction speed, increase the alloy reduction capacity, promote alloy’s co-deposition, and improve the bonding strength between alloy layer and substrate, thus the peeling strength between ultra-thin copper foil and carrier is enhanced.