New Die Attach Adhesive Meets Challenging Performance, Reliability and Cost Objectives of Automotive MCU Packaging

A majority of leadframe-based packages such as QFNs, SOICs, and QFPs are moving from PPF (Pre-plated frame, NiPdAu) leadframes towards copper leadframes due to cost and supply chain concerns. To meet these packages' dynamic cost and reliability demands, a unique resin/filler die attach system has been developed to enable adhesion stability on copper leadframes under high moisture and large die sizeinduced high-stress conditions. In addition, the new die attach adhesive maintains high thermal conductivity of 9 W/m-K to dissipate heat through the exposed pad. The novel material demonstrated good adhesion on copper, passed MSL1 testing, and withstood temperature cycling of 2,000 cycles between - 55°C and 150°C. These results make it a good candidate for high-reliability and high I/O applications such as microcontrollers (MCUs) and other high-performance devices. This paper presents details about the die attach adhesive material properties and in-package reliability performance that were studied, revealing the formulation's excellent copper leadframe compatibility along with MSL1 and AEC automotive grade 0 reliability for exposed pad QFN and QFP packaging.