Package-on-Package Heat Spreader for Thermal and EMI Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The limitations of stacked die packages include low final test yield due to defective dies, significant power dissipation issues without effective heat dissipation paths, and electromagnetic interference between chips, which reduce the reliability and efficiency of integrated circuit packaging in portable electronic devices.
Innovation Solution
A package-on-package system is developed with a base substrate, integrated circuit, stacking interposer, and a heat spreader base that conducts heat away from the integrated circuit while acting as an electromagnetic interference shield, enhancing heat dissipation and reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If multiple die are stacked in a single package to increase functional density, then the footprint and thickness are reduced, but the final test yield decreases due to defective dies
Solution Approach 1:
The patent divides the stacked die structure into separate package modules, where each die is packaged individually before stacking. This segmentation allows each die to be tested and validated independently, ensuring that only functional dies are stacked together, thereby maintaining high final test yield while achieving compact footprint through vertical integration of multiple validated packages.
Solution Approach 2:
The patent performs electrical testing and validation of each die package before stacking them together. This preliminary action ensures that defective dies are identified and rejected prior to assembly, preventing yield loss in the final stacked package. The individual packages are pre-tested to guarantee functionality before being combined into the multi-package module.
2Length of stationary object
If multiple die are stacked in a single package to reduce thickness, then the package becomes more compact, but heat dissipation becomes insufficient leading to reduced chip life
Solution Approach 1:
The patent introduces heat spreader components as intermediaries between the stacked die packages and the external environment. These heat spreaders facilitate efficient thermal conduction and dissipation pathways, allowing heat generated by the compact stacked dies to be effectively transferred away from the package, thereby maintaining operational temperatures and extending chip life despite the reduced thickness.
Solution Approach 2:
The patent addresses heat dissipation challenges in the compact stacked structure by introducing thermal management solutions that extend in horizontal dimensions rather than increasing vertical thickness. Heat spreaders and thermal interface materials are deployed laterally across the package footprint to provide adequate heat dissipation surface area without compromising the reduced thickness advantage of the stacked configuration.
3Device complexity
If no electrical shielding is provided between stacked die, then the package structure remains simple, but electromagnetic interference occurs between RF and digital die
Solution Approach 1:
The patent introduces electromagnetic shielding layers and ground planes as intermediary elements between RF and digital die packages in the stacked structure. These shielding components act as barriers that block or redirect electromagnetic fields, preventing interference between sensitive RF circuits and noisy digital circuits while maintaining a relatively compact package structure without requiring significant structural complexity.
Solution Approach 2:
The patent applies electromagnetic shielding selectively in specific regions where RF and digital die are stacked together, rather than providing comprehensive shielding throughout the entire package. Ground planes and shielding layers are strategically positioned between conflicting circuit types to provide targeted EMI protection only where needed, minimizing added complexity while effectively addressing electromagnetic interference concerns.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively extends the usable life of integrated circuits by improving heat management and shielding against electromagnetic interference, thereby increasing package reliability and manufacturing efficiency.
Implementation Method 1
a heat spreader base around the integrated circuit by coupling the base substrate and the stacking interposer to the heat spreader base
Implementation Method 2
a heat spreader base around the integrated circuit by coupling the base substrate and the stacking interposer to the heat spreader base
Data Source
AI summary
A package-on-package system includes: providing a base substrate; mounting an integrated circuit on the base substrate; positioning a stacking interposer over the integrated circuit; and forming a heat spreader base around the integrated circuit by coupling the base substrate and the stacking interposer to the heat spreader base.