This study proposes a Cu-Sn TLP bonding method that enables bonding at 200℃ by utilizing Sn-Bi alloy plating. First, a Cu plate was electrolytically plated with Sn-3.5Bi alloy, then cut into pieces to use as chip simulants. The chips were heat-treated, intending to lower the melting point of the plating surface by raising the Bi concentration; the Sn in the plating is consumed in the reaction with Cu in the base to form Cu-Sn IMCs by the heat treatment, resulting in the rise of the Bi concentration. Cu-Sn TLP bonding was performed employing the Cu chips and Cu plates at 200℃ to prepare Cu-Cu bonded joint specimens. Shear tests using the joint specimens were conducted at R.T. and 200℃ to evaluate the usefulness of the proposed bonding method.
OHGUCHI et al. (Wed,) studied this question.