Diamond Laminated Substrate With Metal Interlayer for Warp Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high cost and warping issues associated with directly joining a free-standing diamond substrate to a device, such as a semiconductor, necessitate a more cost-effective and stable solution for thermal management.
Innovation Solution
A laminated substrate comprising a three-layer structure of a device substrate, a metal layer, and a diamond layer, where the device substrate is composed of single crystal materials like Si, SiC, GaN, or AlN, and the diamond layer is oriented to reduce warping, thereby providing thermal conductivity at lower costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a free-standing diamond substrate is directly joined to a device, then high thermal conductivity is achieved, but both the diamond substrate and device require mirror-finished surfaces which increases cost
Solution Approach 1:
The patent introduces a metal layer as an intermediary between the device substrate and diamond layer. This metal layer serves as a buffer that accommodates thermal expansion differences and mechanical stress, eliminating the need for expensive mirror-finished surfaces on both the diamond substrate and device while maintaining effective thermal conductivity. The metal layer mediates the interface between dissimilar materials, solving both the thermal management requirement and the cost reduction goal.
Solution Approach 2:
The patent creates a composite structure consisting of a device substrate, metal layer, and diamond layer. This composite material approach combines the advantages of different materials: the device substrate provides mechanical support, the metal layer provides thermal conductivity and stress accommodation, and the diamond layer provides superior heat dissipation. The composite structure achieves high thermal conductivity without requiring expensive mirror-finished surfaces.
2Reliability
If a free-standing diamond substrate is used for heat sink application, then high thermal conductivity is achieved, but warping occurs due to thermal expansion differences
Solution Approach 1:
The metal layer acts as an intermediary that buffers the thermal expansion differences between the device substrate and diamond layer. During thermal cycling, the metal layer accommodates the differential expansion and contraction, preventing warping of the overall structure while maintaining the high thermal conductivity pathway through the diamond layer.
Solution Approach 2:
The patent changes the physical parameters of the interface by introducing a metal layer with intermediate thermal expansion properties. This parameter change allows the structure to accommodate thermal stress without warping, while the diamond layer continues to provide superior heat dissipation performance.
3Reliability
If mirror-finished surfaces are applied to both diamond substrate and device for direct joining, then proper thermal contact is achieved, but manufacturing cost increases
Solution Approach 1:
The metal layer serves as an intermediary that provides adequate thermal contact without requiring mirror-finished surfaces. The metal's ductility and conformability allow it to adapt to surface irregularities, ensuring good thermal contact between the device substrate and diamond layer while eliminating the need for expensive precision surface finishing operations.
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 laminated substrate effectively reduces warping and lowers production costs while maintaining high thermal conductivity, facilitating the integration of diamond as a heat sink material without the need for expensive mirror-finishing.
Implementation Method 1
Diamond is a material having an extremely high thermal conductivity (about 22 W/cm·K), and application of diamond to a heat sink or the like of a device such as a semiconductor device is expected
Data Source
AI summary
There is provided a laminated substrate including a three-layer structure composed of: a device substrate, which is composed of at least one single crystal material selected from the group consisting of Si, SiC, GaN, AlN, BN, Ga2O3, Cr2O3, LiTaO3, and LiNbO3; a metal layer on the device substrate; and a diamond layer on the metal layer.