Title :
Analysis of TAB inner lead fatigue in thermal cycle environments
Author_Institution :
Air Transp. Syst. Div., Honeywell Inc., Phoenix, AZ, USA
fDate :
3/1/1995 12:00:00 AM
Abstract :
The inner leads of a Tape Automated Bonding (TAB) device can be subject to early fatigue failures in thermal cycle environments. This paper describes a 3-D nonlinear finite clement analysis of the failure mechanism, and verifies the results by experiment. Some TAB applications require environmental qualification and electrical testing in the unexcised tape carrier or retain a significant portion of the polyimide tape in the assembly. In these cases the Coefficient of Thermal Expansion (CTE) mismatch between the silicon die and polyimide tape can cause plastic strains in the inner leads. Several design variations are quantified. Those with first order effects were found to be encapsulant material, lead length, and lead material
Keywords :
encapsulation; environmental testing; failure analysis; fatigue; finite element analysis; integrated circuit packaging; lead bonding; plastic deformation; tape automated bonding; thermal expansion; 3D nonlinear finite clement analysis; CTE mismatch; TAB inner lead fatigue; coefficient of thermal expansion; design variations; electrical testing; encapsulant material; environmental qualification; failure mechanism; fatigue failures; first order effects; lead length; lead material; plastic strains; polyimide tape; thermal cycle environments; unexcised tape carrier; Assembly; Bonding; Failure analysis; Fatigue; Plastics; Polyimides; Qualifications; Silicon; Testing; Thermal expansion;
Journal_Title :
Components, Packaging, and Manufacturing Technology, Part A, IEEE Transactions on
