Polycrystalline SiC Wiring Substrate for Heat Dissipation at Lower Cost
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Single-crystal SiC substrates, despite their high heat dissipation performance, have high production costs due to the need for a seed crystal and extraction of a single-crystal portion, and alternative substrates like polycrystalline and SiC multiparticle sintered substrates suffer from lower thermal conductivity and increased micropipe formation.
Innovation Solution
A wiring substrate composed of a polycrystalline SiC substrate containing multiple bulk crystallites with different polytypes, bonded without grain boundary phases, which reduces production costs and maintains high thermal conductivity by controlling micropipe formation and grain boundary orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If single-crystal SiC substrates are used, then heat dissipation performance is improved, but production cost increases
Solution Approach 1:
The patent replaces expensive single-crystal SiC substrates with polycrystalline SiC substrates that have lower production costs. The polycrystalline structure, while not as expensive as single-crystal, still provides adequate heat dissipation performance for the application, effectively using a lower-cost material that meets the performance requirements.
Solution Approach 2:
The patent uses a composite structure consisting of multiple bulk crystallites of SiC with different polytypes (such as 3C-SiC, 6H-SiC, and 15R-SiC) bonded together. This composite polycrystalline structure achieves a balance between heat dissipation performance and production cost, avoiding the need for expensive single-crystal extraction while maintaining adequate thermal conductivity.
2Ease of manufacture
If polycrystalline or SiC multiparticle sintered substrates are used, then production cost is reduced, but thermal conductivity decreases
Solution Approach 1:
The patent controls the parameters of the polycrystalline structure, specifically ensuring that the average grain size of the bulk crystallites is 1 mm or more. This parameter control maintains thermal conductivity close to that of single-crystal SiC while keeping production costs lower. The patent also controls the volume fraction of different polytypes to optimize thermal properties.
Solution Approach 2:
The patent creates regions with different properties within the substrate. By controlling the orientation and size of bulk crystallites in different areas, the substrate achieves optimized thermal conductivity in critical heat dissipation paths while maintaining overall cost-effectiveness. The grain boundaries are oriented to minimize their impact on thermal conduction.
3Ease of manufacture
If polycrystalline SiC substrates are used, then production cost is reduced, but micropipe formation increases
Solution Approach 1:
The patent controls the growth parameters and processing conditions to minimize micropipe formation. By optimizing the sintering temperature, pressure, and atmosphere, as well as controlling the initial powder characteristics, the patent reduces micropipe defects while maintaining the cost advantages of polycrystalline substrates.
Solution Approach 2:
The patent accepts the polycrystalline structure with its inherent grain boundaries and potential micropipes, but converts this potential weakness into an advantage by carefully controlling the grain structure. The grain boundaries are oriented and sized to actually help distribute stress and prevent crack propagation, while the controlled micropipe formation is minimized through optimized processing. This transforms the polycrystalline structure from a potential defect source into a reliable, cost-effective material.
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 solution provides a cost-effective substrate with high thermal conductivity and reduced micropipe-related issues, enhancing insulation and heat dissipation properties while minimizing stress and peeling risks, thus improving the reliability of electronic components.
Implementation Method 1
the insulating substrate containing multiple bulk crystallites of SiC with different polytypes
Data Source
AI summary
A wiring substrate includes an insulating substrate including a first surface and a wiring conductor located at the insulating substrate, the insulating substrate containing multiple bulk crystallites of SiC with different polytypes. An electronic device includes the wiring substrate described above and an electronic component mounted on the wiring substrate. An electronic module includes the electronic device described above and a module substrate on which the electronic device is mounted.