Hierarchical Power Distribution for 3D IC Stacks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Three-dimensional integrated circuits face challenges in efficient power distribution due to high current density issues and the need for numerous supply rails across different die layers, which can lead to practical limitations in the number of through-silicon vias required.
Innovation Solution
A hierarchical power distribution approach is implemented, using a high voltage global rail and local down converters, along with a mix of die-to-die and on-die capacitors for local power regulation, and centralized power state management to define finer grain power throttling and adaptive address remapping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If traditional power distribution with multiple supply rails is used in 3D integrated circuits, then power can be delivered to different die layers, but current density becomes excessively high and the number of required through-silicon vias increases
Solution Approach 1:
The patent transitions from planar power distribution to three-dimensional power distribution by stacking multiple die layers vertically. Power delivery is achieved through vertical through-silicon vias that connect power supply rails across different die layers, enabling power distribution in the vertical dimension rather than relying solely on horizontal routing within single dies. This dimensional change reduces the complexity of power distribution by utilizing the third dimension for via placement and power rail organization.
Solution Approach 2:
The power distribution system is segmented into multiple independent power supply rails, each serving specific die layers or functional blocks. Instead of using a single comprehensive power network, the system divides power delivery into separate segments that can be independently controlled and optimized. This segmentation allows for finer-grain power management and reduces the current density on individual vias and rails by distributing the total power load across multiple parallel paths.
2Device complexity
If high current density is tolerated to reduce the number of supply rails, then device complexity decreases, but reliability and performance are compromised
Solution Approach 1:
The patent implements local power management by placing voltage regulators and power management circuits on specific die layers where they are needed. Each die layer or functional block can have its own local power regulation, allowing for optimized current density control in different regions of the 3D stack. This local quality approach ensures that reliability is maintained in high-current regions while allowing for reduced complexity in lower-power regions.
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
This solution reduces current density on interconnect structures, decreases the number of required supply rails, and enables more granular power control, improving efficiency and energy savings by optimizing power distribution across multiple die layers.
Implementation Method 1
A mix of die-to-die capacitors (capacitors disposed between adjacent die layers) and on-die capacitors may be used for local power regulation
Implementation Method 2
Power traverses the stack on conductive paths through wafer interconnects
Data Source
Figure 1
Figure 2~4
Figure 3
AI summary
Multiple dies can be stacked in what are commonly referred to as three-dimensional modules (or "stacks") with interconnections between the dies, resulting in an IC module with increased circuit component capacity. Such structures can result in lower parasitics for charge transport to different components throughout the various different layers. In some embodiments, the present invention provides efficient power distribution approaches for supplying power to components in the different layers. For example, voltage levels for global supply rails may be increased to reduce required current densities for a given power objective.