Wafer Bumping with Electroless Deposition of Ni/Au and/or Ni/Pd/Au - International Wafer-Level Packaging Conference

摘要

The utilization of electroless Nickel/Gold as a low cost under bump metallization for flip-chip and wafer-level CSP application is meanwhile well established in the industry. However, new technical requirements and challenges are producing strong interest in the electroless metallization process also in other, more performance driven technology Especially electroless Palladium deposited in between the Ni and Au layer provides new superior properties with regard to wire bond capabilities or, in the case of solder application, intermetallic growth behavior. This paper is providing a technology roadmap by discussing an electroless Ni and electroless Pd process flow for both, Au wire bond and lead-free solder application.