Functional surfactants in lubricant for microelectronic industry

Abstract

The functional surfactants, as the additional additives in the standard glycol-based lubricant were studied and optimized to reduce and protect the surface of the magnetic read/write head from deposited contaminants during the lapping processes. The scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) results identified that the black contamination was bismuth (Bi) particles, came out from lapping plate during the lapping process due to wear. Selected surfactants exhibited the results in reduce and prevent the deposition of contaminants by forming the micelle beyond their critical micelle concentration (CMC) values. We found that both polyethoxylate alcohol (PEAL) and quaternary amines (QA) can form their micelle in glycol-based lubricant at the ratio of 1 %wt. Polyoxyethylene sorbitan monolaurate (PO) can protect the surface by its oxyethylene groups group at the 0.2 %wt in based lubricant. The characteristics and performances of modified lubricants were measured the change in magnetoresistive resistance value (%DMRR) from quasi-static test (QST). The modified lubricants had minor distribution failure of slider lower than standard lubricant. Moreover, the potentiodynamic polarization measurement results indicated that additional surfactant can also yield almost 300% better performances than the standard lubricant in term of corrosion protection during lapping processes. Thus, these surfactants can function both as the contamination protective additive and as anti-corrosion additive. These modified lubricants can also keep the lap time and other physical performances to match the fabrication requirements.