Stress Analyses of Flip TAB Interconnects in Multi-Chip Module Assembly

Abstract

Flip Tape Automated Bond (FTAB) interconnect is one of the leading candidates for device to substrate interconnection in a high performance Multi-Chip Module (MCM). The TAB interconnect becomes a structural member in the MCM assembly, bearing both “mechanical” and “thermal” loads. Further, to accomplish high thermal performance in the assembly, physical contact to the device may be made under substantial contact pressures. The device may be supported by elastic structures to redistribute the interconnect forces. Finite Element Methods (FEM) are used to analyze the structural behavior of TAB interconnects under (i) the applied mechanical load to the device and (ii) the thermal loads due to the heat dissipation in the device. Variation of the force components on the TAB interconnects and the maximum failure criterion based on the stresses in the interconnects are reported. Effect of the support area and the modulus of the supporting element on the interconnects are discussed. Generic design guidelines are presented for flip TAB interconnect based MCM assembly.