NFT Wing Protection on HAMR Head Using a Window Underlayer Structure

Ensuring the mechanical reliability of the NFT is critical due to contact with the disk during touchdown and the presence of high thermal asperities (TAs) at low clearance. Here, we tune the thermomechanical design of the HAMR head to ensure the NFT is protected from direct contact with the disk. We propose embedding the NFT in a localized window of underlayer material chosen for its small thermal expansion in comparison to a standard material such as alumina. By optimizing the size and material properties of the window structure, simulation predicts that the NFT is well protected under recording conditions.