A Novel Disaggregated Approach of Assembling Integrated Heat Spreader for Advanced Packages

With the increment of product thermal design power (TDP), packaging complexity and form factor, there is a need of innovative integrated heat spreader (IHS) assembly solutions for advanced packages. A disaggregated approach of IHS assembly can be a great solution for complex semiconductor products. This approach helps to simplify complex IHS manufacturing process and enable advanced packages which otherwise would not be feasible due to the manufacturability issues or cost. The two critical components of assembling IHS using disaggregated method are assembly process flow and adhesive selection. This paper will focus on the impact of assembly flow and adhesives on the thermal interface material (TIM) performance and package shape behavior. It was found through data collection that the package coplanarity incoming to IHS attach can be reduced by 7 % if stiffener is attached before the die attach process as opposed to post die attach. It was also found that the package coplanarity can be reduced by 30 % when stiffeners are attached before flat plate IHS assembly.