Widely used as a substrate for general masking and EMI/ RFI shielding applications. Aluminium possesses excellent chemical and heat resistance. It is largely unaffected by exposure to many acids and bases (alkali) and maintains its mechanical resilience up to temperatures of 500oC. In terms of shielding effectiveness (S.E.) aluminium is not as effective as copper. This is due to its lower level of conductivity and the tough nature of aluminium’s oxide layer which impairs it’s chemical resistance and prevents it from being soldered.