China’s CNIPA recently published a new patent filed by Huawei, titled “flip chip package with improved thermal performance.” The patent showcases a heat management solution for packaging chips with high resistance to thermal conditions. This innovation has the potential to enhance the performance of various chipsets, including CPUs, GPUs, FPGAs, and ASICs, in electronic devices like smartphones, tablets, PCs, and servers.
Proper thermal management is crucial for chipsets as they bear the load of device operations, generating heat. Without effective measures, overheating can result in decreased performance, shorter lifespan, and component damage. To address this, Huawei’s flip chip packaging technology offers improvements in heat reduction. The chip is connected to the substrate through underlying bumps, enabling the positioning of a heat sink on the chip’s top surface.
To enhance the cooling system, a thermal interface material (TIM), such as thermal grease, is applied between the chip’s top surface and at least a portion of the heat sink. Reducing the thermal resistance in the TIM is crucial for improving the package’s thermal performance, and Huawei achieves this by controlling the thickness of the TIM. The thickness is determined by the height of a wall-like structure in the molded component.
The patent details a flip-chip package that consists of a chip connected to a substrate, with a molded die formed on the substrate to wrap the chip’s side portion and expose its top surface. The molded member has a first region where the chips’ top surfaces are continuous, a second region with applied adhesive, and a wall-like structure surrounding the top surfaces. Heat sinks are placed on top of the chips and bonded to the molded member using adhesive filled in the second region. Thermal interface material fills the first region, present between the chip’s top surface and the bottom surface of the heat sink.
It’s important to note that Huawei has not announced the practical application of this flip-chip packaging patent for heat management at this time.