Electronic devices and methods for fabricating electronic devices are described. One method includes providing a plurality of first metal bumps on a first surface, and a plurality of second metal bumps on a second surface, wherein at least one of (i) the plurality of first metal bumps, and (ii) the plurality of second metal bumps, comprises a solder. The method also includes forming a metal region including indium and tin, on at least one of (i) the plurality of first metal bumps, and (ii) the plurality of second metal bumps. The method also includes positioning the first metal bumps on the second metal bumps, and heating the metal bumps and the metal region and melting the solder. Other embodiments are described and claimed.