The reliability of lead-free Cu bonding technology is often limited by high bonding temperature and perpetual growth of intermetallic compounds between Sn solder and Cu substrate. Here, we report a low-bonding-temperature and highly reliable Cu bonding strategy with the use of graphene as an interlayer. By integrating a nanoscale graphene/Cu composite on the Cu substrate prior to thermocompression bonding, we observe a macroscale phenomenon where reliable Sn-Cu joints can be fabricated at a bonding temperature as low as 150 °C. During the bonding process, nanoscale features are replicated in the Sn solder by the Cu nanocone array morphology. Compared to microscale Sn, nanoscale Sn is mechanically weaker and thus can distribute on the Cu substrate at a much lower temperature. Furthermore, insertion of a graphene interlayer, which is one atom thick, can successfully retard the intermetallic compounds' growth and preserve a high bonding yield, following 96 h of aging, as confirmed through SEM and shear strength analyses. Our graphene-based Cu bonding strategy demonstrated in this work is highly reliable, cost-effective, and environmentally friendly, representing a much closer step toward industrial applications.

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A heterogeneous photo-Fenton catalyst was prepared using the complex tris(1,10)-phenanthroline iron(II) loaded on the NaY type of zeolite. The catalyst displayed a feature of the photo-Fenton degradation of methylene blue, and a linear relationship between ln(C 0 /C t ) and reaction time was obtained, indicating the kinetic characteristics of a pseudo first-order reaction. The repeated cyclic experiments showed that the heterogeneous catalyst was stable and recoverable. Compared with the traditional homogeneous Fenton reagent, the heterogeneous catalyst has the advantage in the neutral or weakly basic medium used because the active component tris(1,10)-phenanthroline iron(II) is a stable chelate compound. The photoFenton degradation pathway for methylene blue was given based on the mass spectral data.

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