Native Silicon Oxide Lid for IC Thermal Management
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Solution Overview
Problem
Conventional lidded IC packages face inefficiencies in heat transfer due to the use of thick, conventional silicon oxide layers and nickel coatings, which can lead to delamination and reduced thermal conductivity, affecting the overall heat dissipation from semiconductor dies.
Innovation Solution
A lidded IC package design featuring a native silicon oxide layer formed on a crystallized amorphous silicon film, interfacing with a nickel layer on a copper substrate, and a thermal interface material like silicone or epoxy resin, enhancing heat transfer efficiency and delamination resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick silicon oxide layer is used to interface with thermal interface material, then adhesion is improved, but thermal conductivity deteriorates
Solution Approach 1:
The silicon oxide interface is segmented into multiple thin layers (first silicon oxide layer and second silicon oxide layer) separated by a nickel layer, replacing a single thick oxide layer. This segmentation maintains adhesion functionality while reducing overall oxide thickness to improve thermal conductivity.
Solution Approach 2:
The interface structure uses a composite material approach combining multiple materials (copper, nickel, silicon oxide) in a layered configuration. The copper substrate provides thermal conductivity, nickel layers provide adhesion and structural integrity, and thin silicon oxide layers provide electrical isolation, achieving optimal balance of properties.
2Loss of energy
If a nickel coated copper lid is used, then thermal conductivity is improved, but delamination occurs
Solution Approach 1:
The nickel coating is segmented into multiple thin layers distributed throughout the structure (first nickel layer and second nickel layer), rather than a single thick coating. This segmentation prevents stress concentration and delamination while maintaining thermal conductivity through the copper substrate.
Solution Approach 2:
Thin silicon oxide layers are introduced as intermediary layers between the nickel layers and thermal interface material. These intermediary layers reduce stress and prevent direct adhesion failures, thereby preventing delamination while allowing thermal conduction through the copper-nickel-silicon oxide composite structure.
3Reliability
If physical vapor deposition is used to apply silicon dioxide coating, then adhesion is improved, but manufacturing complexity increases
Solution Approach 1:
The coating process is segmented into multiple deposition steps creating thin alternating layers of nickel and silicon oxide. While this requires multiple deposition cycles, each layer is thin and can be applied using standard physical vapor deposition techniques, making the process manageable and scalable.
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 native silicon oxide layer improves heat transfer efficiency and delamination resistance, providing a more effective thermal interface with improved shear strength and moisture resistance, while maintaining a thinner, more efficient structure compared to conventional methods.
Implementation Method 1
The silicon oxide layer facilitates heat flow between the semiconductor die and the lid
Implementation Method 2
A thermal interface material such as silicone or epoxy is positioned between the die and the lid. The thermal interface material facilitates heat flow between the semiconductor die and the lid
Implementation Method 3
A heat sink is typically mounted on the upper surface of the lid to receive and disperse heat from the lid
Implementation Method 4
A heat sink is typically mounted on the upper surface of the lid to receive and disperse heat from the lid
Implementation Method 5
Physical vapor deposition typically uses evaporation or sputtering techniques to apply a silicon dioxide coating by condensation of vapors in a vacuum resulting in adhesion between the deposited atoms and atoms of the nickel layer
Data Source
AI summary
A lid has a heat conductive substrate, a crystallized amorphous silicon layer and a native silicon oxide layer formed on the crystallized amorphous silicon layer. Another embodiment has a lid with a copper substrate and a native silicon oxide layer connected to the substrate by at least one intermediate layer. A method of providing a heat path through an integrated circuit package includes providing a substrate with an exterior layer of native silicon oxide and interfacing the layer of native silicon oxide with a layer of thermal interface material.