Abstract: A linear pad conditioning mechanism provides a linear in situ or ex situ conditioning for a polishing pad mounted on a polishing belt of a CMP apparatus. The linear pad conditioning mechanism includes a linear oscillation mechanism for driving a conditioning pad in a direction orthogonal to the polishing belt's direction of travel. In one example, multiple conditioning assemblies are provided to each provide a trapezoidal conditioning pad, and the conditioning assemblies are positioned such that a constant-width area in the polishing belt's direction of travel is provided. In that example, a rotational mechanism is provided to position the conditioning pad between a conditioning position against the polishing pad, and a cleaning position in a bath of cleaning fluid. Further, each conditioning assembly is provided a fluid delivery system to a conditioner block, so that a conditioner fluid can be delivered at the point of use.