A semiconductor structure bonding apparatus is disclosed. The apparatus may include a leveling adjustment system configured to provide leveling adjustment of upper and lower block assemblies of the apparatus. In some cases, the leveling adjustment system may include a plurality of threaded posts, differentially threaded adjustment collars, and leveling sleeves. In some instances, the leveling adjustment system further may include a plurality of preload springs configured to provide a given preload capacity and range of adjustment. In some instances, the leveling adjustment system further may include a load cell through which one of the threaded posts may be inserted. In some embodiments, the upper block assembly further may include a reaction plate configured to reduce deformation of the upper block assembly. In some embodiments, the upper block assembly further may include a thermal isolation plate configured to provide compliance deflection and being of monolithic or polylithic construction, as desired.