Joint Surface Metallurgy for Thin Film Packaging
Original Publication Date: 1987-Jan-01
Included in the Prior Art Database: 2005-Jan-31
It has been proposed to use Zr as an adhesion layer in Cu-Ni-Au thin film metallurgy for wire bonding and chipping applications. The use of Zr instead of the Ti or Cr typically used provides a thin film adhesion interlayer with lower stress and better tolerance-to-surface preparation. Use of Zr provides an enhanced alternative metallurgy as it offers a lower stress factor than that of several sandwich metals. This is a critical factor in reducing film stresses. Additionally, Zr has shown better tolerance to various cleaning steps and still provides tenacious bonding to a ceramic surface. The drawing illustrates the nugget failure mode of pull tests indicating excellent Zr adhesion to a ceramic substrate.