Structure Reliability Analysis of Embedded MicroChannel Cooling with PCB Manifold

The power density of advanced electronic modules in the fields of RF microsystems, high-performance computing, has exceeded the order of kW/cm ² , which poses severe challenges to the efficient heat dissipation ability of modules. Manufacturing embedded microchannels in electronic modules through MEMS process to obtain highefficiency liquid cooling heat dissipation capabilities is an important technical way to break through the "thermal bottleneck". The embedded microchannel brings efficient heat dissipation capabilities, but also brings unprecedented reliability challenges, due to its working environment with high temperature and pressure. In its long-term service, processes such as particle erosion, corrosion and clogging or fouling may occur, resulting in excessive stress, chip warpage, liquid leakage, etc., which affect the heat dissipation performance and cause chip failure. In this paper, the highly accelerated temperature and humidity stress testing, temperature shock testing and shear strength tests were carried out to evaluate the structural reliability of the gold-tin eutectic bonded PCB manifold and microchannel. The bonding interface was studied by X-ray before and after the test, which showed the bonding interface has no significant change, while the interface shear strength decreased. In addition, temperature cycling experiments were performed under working fluid flow conditions and changes in heat dissipation performance were detected. The results show that under the volume flow rate of 300~700 mL/min, considering the influence of experimental error, the thermal resistance and temperature rise of the sample are basically unchanged. As far as we know, there are currently no studies in the world in this regard. This work has important implications for advancing the practical application of embedded microchannel cooling.