Thermal-Structural Analysis Of Electronic Components

Increasing scale of integration and consumption of power has led to the significant increase in power densities encountered in modern electronic devices, meanwhile, high packaging density tends to generate more power in a package and cause serious thermal problem. Temperature fluctuations caused by either power transients or environmental changes, along with the resulting thermal expansion mismatch between the various materials, results in time and temperature dependent creep deformation of solder.Finite element method (FEM) was used to simulate thermal problems in electronic components. Finite element models and APDL programs were built in ANSYS to conduct thermal-mechanical analysis. The aim was trying to find some possible reasons and trends which affect the reliability of electronic components and give some useful suggestions for thermal design. The main studies are as following:1. 3-D thermal models of a kind of electronic components for special use in air-conditioner were established. Thermal-structural analysis was conducted, while changing the thickness of chip and the location of heat, to investigate temperature distribution and find the required heat convection coefficient. Stress was also calculated to retain stress-strain distribution.2. Thermal-structural analysis was carried out to investigate the effect of bubble in solder on heat transfer and stress distribution. Taking the scale and location of bubble in solder into consideration, simulations are carried out, respectively, with the application of'Birth and death'FE element function. The results are analyzed and compared. When volume ratio of bubble in solder increased, effect on heat transfer becomes obvious, and that, compared with the midst, bubble located in the fringe has further effect on heat transfer. The effect of bubble size in solder on equivalent strain was not significant when bubbles are at the centre of solder attachment, while bubble location had more significant effect on maximum equivalent strain compared to bubble size.