Effect of lead frame design and thickness of Dual Row Quad Flat No Lead Package (DR-QFN)

This study presents the thermo-mechanical stress characteristic of the Dual Row Quad Flat No Lead (DR-QFN) of a 44 lead DR-QFN package with staggered lead frame design and 48 lead DR-QFN package with inline lead frame design. The steady-state structural analysis for DR-QFN package with different lead frame design is performed using ANSYS software. The stress behavior of DR-QFN package with different lead frame thickness also been presented in this study. The 3D models used in this study were developed using finite element method with SOLID 70 and MESH 200 element types. From the study, results show that thinner lead frame gives smaller value of stress. DR-QFN package with lead frame thickness of 0.15 mm has 6% smaller value of stress compared to package with lead frame thickness of 0.20 mm. For lead frame configuration analysis in the DR-QFN package, both staggered and inline lead frame design, show no significant differences in terms of displacement and stress value. As a conclusion the stress can be reduced by using thinner lead frame.