Simulation Study on the Micro Chip Mounting Technology on Complex Curved Surfaces by Anisotropic Conductive Adhesive

To investigate the influence of substrate curvature and process deviations on the bonding quality of microchips mounted on curved surfaces, a thermo–mechanical coupled finite element model was developed in ANSYS 19.2 using a 0402 microchip as a representative component. The model was employed to evaluate the effects of substrate curvature radius, chip placement position, chip angular misalignment, and thermocompression-head angular deviation on the stress distribution and bonding behavior during conformal assembly. The simulation results were further validated through thermocompression bonding experiments. The results show that decreasing the substrate curvature radius significantly increases the stress concentration in the chip-pad region and leads to a more non-uniform stress distribution. In addition, placement errors and loading-direction deviations adversely affect bonding quality by altering the contact stress distribution and increasing the tendency for chip displacement and sliding. Quantitative analysis reveals the relative sensitivity of bonding performance to different geometric and process parameters, providing insight into the dominant thermo–mechanical mechanisms governing curved-surface assembly. Experimental results further demonstrate that excessive thermocompression tilt angles can significantly reduce bonding strength and increase chip sliding, suggesting that the tilt angle should be controlled within an appropriate range to ensure assembly reliability. The proposed thermo–mechanical modeling approach provides a quantitative tool for evaluating the influence of process variations on curved-surface microchip assembly and offers practical guidance for process parameter selection, tolerance control, and reliability-oriented design of conformal electronic packaging.