Wafer Bonding Thermal Channels for IC Heat Dissipation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wafer bonding processes do not effectively address the issue of thermal conductivity, leading to inefficient heat dissipation in integrated circuits.
Innovation Solution
The formation of thermal conductive channels in both the device and carrier wafers, which are bonded together, allowing for improved heat dissipation through direct metal-to-metal bonding or physical contact, enhancing the thermal conductivity of the resulting package.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional wafer bonding techniques are used, then bonding between carrier and device wafers is achieved, but thermal conductivity is insufficient leading to poor heat dissipation
Solution Approach 1:
The patent applies local quality by creating thermal conductive channels at specific locations within the bond layer rather than uniformly modifying the entire bond layer. These channels are strategically positioned to provide thermal pathways from heat-generating regions to heat dissipation regions, thereby improving heat dissipation performance where it is most needed while maintaining the overall bonding structure.
Solution Approach 2:
The patent employs composite materials by combining the bond layer (made of materials like silicon oxide, silicon nitride, or silicon oxynitride) with thermal conductive channels (made of materials with high thermal conductivity such as metal or doped semiconductor materials). This composite structure allows the bond layer to maintain its bonding function while the embedded thermal conductive channels provide enhanced thermal conductivity for improved heat dissipation.
2Stability of the object's composition
If carrier wafer bonding is performed without thermal conductive channels, then packaging structure is formed, but warpage occurs due to mismatched coefficients of thermal expansion
Solution Approach 1:
The patent addresses thermal expansion mismatch by incorporating thermal conductive channels made of materials with thermal expansion properties that can accommodate or compensate for the mismatch between the carrier wafer and device wafer. These channels provide a gradual transition zone that reduces stress accumulation during thermal cycling, thereby preventing warpage and maintaining structural stability.
3Temperature
If thermal conductive channels are formed in bond layer, then heat dissipation is improved, but manufacturing process complexity increases
Solution Approach 1:
The patent applies preliminary action by forming the thermal conductive channels within the bond layer during the bonding process itself, rather than adding them as a separate post-bonding step. The channels are created in the bond layer material before or during the bonding operation, allowing the bonding and thermal conduction features to be integrated in a single process flow, thereby minimizing additional manufacturing complexity.
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 implementation of thermal conductive channels in the wafers significantly improves the thermal conductivity of the integrated circuit package, facilitating better heat dissipation and reducing warpage due to coefficient of thermal expansion mismatches.
Implementation Method 1
The heat generated in the device die may be conducted through the thermal conductive channels
Data Source
AI summary
A method includes forming a first bond layer on a first wafer, and forming a first thermal conductive channel extending into the first bond layer. The first thermal conductive channel has a first thermal conductivity value higher than a second thermal conductivity value of the first bond layer. The method further includes forming a second bond layer on a second wafer, and forming a second thermal conductive channel extending into the second bond layer. The second thermal conductive channel has a third thermal conductivity value higher than a fourth thermal conductivity value of the second bond layer. The first wafer is bonded to the second wafer, and the first thermal conductive channel at least physically contacts the second thermal conductive channel. An interconnect structure is formed over the first wafer. The interconnect structure is electrically connected to integrated circuit devices in the first wafer.