Reducing Bonding Temperature and Energy Consumption in Electronic Packaging Using Flash Electro-Thermal Carbon Fiber Heating Elements

Abstract

Semiconductor packaging based on an epoxy molding compound(EMC)currently has several disadvantages including warpage, limited processingarea, and variability that all negatively affect cost and productionyield. We propose a facile EMC molding process method using a flashelectro-thermal carbon fiber heating (FE-CH) device based on carbonfiber-based papers to manufacture an EMC molded to a copper substrate(EMC/Cu bi-layer package) via Joule heating, and using this device,a modified cure cycle that combines the conventional cure cycle (CCC)with rapid cooling was performed using FE-CH to reduce the curvatureof the EMC/Cu bi-layer package. Compared to the conventional hot pressprocess, which uses 3.17 MW of power, the FE-CH process only uses32.87 kW, resulting in a power consumption reduction of over 100 timeswhen following the CCC. Furthermore, the FE-CH-cured EMC/Cu bi-layerpackage exhibits mechanical properties equivalent to those of a hotpress-cured specimen, including the degree of cure, elastic modulus,curvature, bonding temperature, residual strain, and peel strength.The modified cure cycle using the FE-CH results in a 31% reductionin residual strain, a 32% reduction in curvature, and a 47% increasein peel strength compared to the CCC, indicating that this new processmethod is very promising for reducing a semiconductor package'sprice by reducing the process cost and warpage.