An end effector is provided for conditioning pads used to polish semiconductor wafers. The end effector has a substrate with a matrix (preferably a polymer) disposed thereon. Abrasive particles such as diamond crystals are embedded in the matrix. Preferred particle size and number/spacing is provided for optimal conditioning. The particles are embedded by at least a predetermined amount (e.g., 75%) so as to provide uniform/repeatable conditioning while avoiding dislodged particles. The particles may be embedded such that the tips thereof are coplanar, or such that the profile of diamond tips form a plurality of curved regions. A method for checking end effector quality is also provided.