Flip‐chip solder bonding is a suitable technology for applications involving large numbers of interconnections. This technique, also known as controlled collapse solder bonding, was developed several years ago [L. F. Miller, IBM J. Res. Develop. 239 (1969)]. To facilitate reflow and bonding of flip‐chip devices using Pb–Sn solder, a method of removing the surface oxides on the molten solder is required. Conventional liquid fluxes are not desirable due to potentially corrosive residues that may be difficult to remove from the confined geometry between flip‐chip and substrate. Dry processing previously reported [P. A. Moskowitz, H. L. Yeh, and S. K. Ray, J. Vac. Sci. Technol. A 4, 838 (1986)] involves the use of halogen containing gases such as CF2Cl2, CF4 , and SF6 . However, halide residues on the surfaces of treated samples can corrode the solder surface and any other exposed metal when exposed to atmospheric moisture. This paper describes dry reflow and bonding of flip chips using Pb–Sn solder with atom...