Semiconductor Heat Spreader With Substrate Fins
Solution Overview
Problem
Modern semiconductor packages face challenges with uneven thermal energy distribution and increased power density, which conventional heat spreaders and heat sinks fail to adequately address, limiting their performance and size efficiency.
Innovation Solution
A semiconductor device with a heat spreader featuring a base and protruding fins is mounted on the substrate, creating a thermal conduction path that directs heat from the die into the substrate, allowing for uniform heat dissipation and enabling the use of the entire bottom surface for I/O pins, thereby improving thermal performance and package density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional heat spreaders and heat sinks are used, then heat dissipation is provided, but uneven thermal energy distribution and high power density effects are not adequately mitigated
Solution Approach 1:
The heat spreader is segmented into a base portion and multiple fin portions extending into the substrate. This segmentation creates multiple thermal conduction pathways distributed throughout the substrate, transforming the single conventional heat spreader into a multi-path thermal management system that effectively addresses uneven thermal energy distribution.
Solution Approach 2:
The fin portions of the heat spreader are nested within the substrate, with fins extending downward into the substrate volume. This nesting configuration allows the heat spreader to utilize the substrate interior space for thermal conduction, maximizing heat dissipation efficiency while maintaining compact package dimensions.
2Area of stationary object
If the die is mounted cavity-up to allow I/O pins on the bottom surface, then package area is reduced, but thermal management challenges increase due to higher power density
Solution Approach 1:
The heat spreader extends the thermal conduction path from the traditional top-surface configuration into the vertical dimension by having fin portions extend downward into the substrate. This dimensional transition allows heat dissipation to occur throughout the substrate volume rather than just at the surface, effectively managing thermal loads in compact cavity-up packages.
3Productivity
If package density is increased to reduce size, then more transistors are packed, but heat generation and thermal management difficulties increase
Solution Approach 1:
The heat spreader provides localized thermal management by positioning fin portions at specific locations within the substrate where heat generation is most intense. This local quality approach allows targeted heat extraction from high-power-density regions without requiring the entire package to be oversized for thermal management.
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 configuration enhances thermal performance by reducing temperature gradients and heat flux, allowing for more efficient heat dissipation and smaller package sizes while maintaining the advantages of flip chip connections.
Implementation Method 1
a thermal conduction path exists between the base of the heat spreader and the die. The fins extend into the substrate conducting heat away from the die and into the substrate
Data Source
Figure 1~3
Figure 4A~4C
Figure 5~7
AI summary
A semiconductor device includes a die, a substrate, a heat spreader and a plurality of signal interconnects extending from the die. The heat spreader has a base and a plurality of fins. The heat spreader is mounted on the substrate in such a way that the base of the head spreader is in thermal communication with the die. The fins protrude downwardly into the substrate conducting heat away from the die and into the substrate.