Core-Shell Thermally Conductive Composite for Electrical Insulation
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Solution Overview
Problem
Existing thermal conductive fillers, such as silicon carbide and aluminum nitride, suffer from defects like poor insulation, high hardness, and hydrolysis instability, which affect the performance and longevity of electronic products and devices when used in composite materials.
Innovation Solution
A composite material is developed with a core-shell structure, where the core has a thermal conductivity of at least 20 W/(m·K) and is coated with a metal salt shell, formed through sintering, to enhance bonding and compensate for the core's defects, ensuring tight adherence and improved aging resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If silicon carbide is used as thermal conductive filler, then thermal conductivity is improved, but electrical insulation deteriorates
Solution Approach 1:
The patent applies composite materials by combining silicon carbide core with magnesium silicate shell to create a composite filler that simultaneously achieves high thermal conductivity from the silicon carbide and electrical insulation from the magnesium silicate coating, resolving the contradiction between thermal performance and electrical insulation
Solution Approach 2:
The patent applies local quality by creating a core-shell structure where the inner silicon carbide core provides thermal conductivity while the outer magnesium silicate shell provides electrical insulation, allowing different regions of the same filler particle to have different functional properties
2Temperature
If aluminum nitride is used as thermal conductive filler, then thermal conductivity is improved, but hydrolysis stability deteriorates in high-humidity environment
Solution Approach 1:
The patent uses composite materials by coating aluminum nitride core with magnesium silicate shell, where the magnesium silicate layer acts as a protective barrier that prevents hydrolysis of the aluminum nitride in high-humidity environments while maintaining its thermal conductivity
Solution Approach 2:
The patent applies beforehand cushioning by pre-coating the aluminum nitride core with magnesium silicate before use, creating a protective barrier in advance that prevents hydrolysis damage when the material is exposed to high-humidity environments
3Temperature
If silicon nitride is used as thermal conductive filler, then thermal conductivity is improved, but device wear increases due to high hardness
Solution Approach 1:
The patent applies composite materials by combining silicon nitride core with magnesium silicate shell, where the hard silicon nitride core provides thermal conductivity while the softer magnesium silicate shell reduces wear on contacting devices
Solution Approach 2:
The patent applies local quality by creating a core-shell structure where the inner silicon nitride core maintains high hardness for thermal conductivity while the outer magnesium silicate shell provides a softer surface that reduces wear on other devices
4Ease of manufacture
If physical integration process is used to form core-shell structure, then manufacturing ease is improved, but shell-core bonding strength deteriorates
Solution Approach 1:
The patent replaces the mechanical physical integration process with a chemical reaction-based sintering process, where magnesium oxide reacts with silicon carbide or aluminum nitride at high temperature to form magnesium silicate shells that are chemically bonded to the cores, significantly improving bonding strength
Solution Approach 2:
The patent applies parameter changes by using high-temperature sintering conditions to enable chemical reactions between the core and shell materials, transforming the bonding mechanism from physical adhesion to chemical bonding and thereby improving bond strength
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 composite material maintains high thermal conductivity while addressing insulation and hardness issues, providing better aging resistance and uniform dispersion in matrix materials, enhancing the performance of thermal conductive mixtures.
Implementation Method 1
a shell containing a first metal salt obtained by sintering
Implementation Method 2
at least part of the shell raw material undergoes mass transfer on the surface of the core
Data Source
AI summary
A composite material and a preparation method therefor are provided. The composite material comprises an inner core and a shell coating the outside of the inner core, wherein the thermal conductivity of the inner core material is not less than 20 W/m·K, and the material of the shell comprises a first metal salt. The composite material satisfies the following conditions: D501 of the composite material is A, the composite material with a mass of M is placed in a container with a stirring device, is stirred for 10 min under the condition of a charging coefficient being 0.4 and 500 r/min, and then passes through a (0.1-0.3)×A sieve, and the amount of screen underflow is not higher than 0.05×M. The composite material can make up defects of the inner core material, the aging performance is relatively good, and the heat conductivity coefficient is also relatively high.