Spherical AlN Particles for Thermal Interface Materials
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Solution Overview
Problem
Existing heat dissipation materials face challenges in achieving high thermal conductivity and fluidity due to surface asperities on aluminum nitride (AlN) particles, which affect their fillability in resins used for thermal interface materials.
Innovation Solution
Incorporating a specific ratio of Zr compounds into alumina or alumina hydrate powders during the nitridation reduction process to produce spherical AlN particles with smooth surfaces, enhancing their fluidity and thermal conductivity by controlling the AlN conversion rate and circularity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If AlN particles are produced by nitridation reduction method, then thermal conductivity is improved, but surface asperities form which deteriorate fluidity and fillability
Solution Approach 1:
The invention changes the chemical composition parameters by adding specific elements (Si, B, Al, Ga, In, La, Ce, Pr, Nd, Dy, Ho, Er, Tb, Mn, Fe, Co, Ni, Cu, Zn, Ag, Pd, Pt, Au, Hf, Ti, V, Nb, Ta, Mo, W, Re, Os, Ir, Pt, Au) to the alumina starting material. This modifies the particle formation process during nitridation reduction, resulting in AlN particles with smooth surfaces and controlled crystal structure that maintain high thermal conductivity while eliminating surface asperities that would otherwise reduce fluidity and fillability.
Solution Approach 2:
The invention creates composite AlN particles by incorporating multiple elements (Si, B, Al, Ga, In, La, Ce, Pr, Nd, Dy, Ho, Er, Tb, Mn, Fe, Co, Ni, Cu, Zn, Ag, Pd, Pt, Au, Hf, Ti, V, Nb, Ta, Mo, W, Re, Os, Ir, Pt, Au) into the alumina matrix before nitridation. This composite approach allows the particles to inherit the high thermal conductivity of AlN while the incorporated elements control surface morphology and crystal growth, producing smooth surfaces that improve fluidity and fillability in resin matrices.
2Temperature
If high crystallinity AlN filler is used, then thermal conductivity is improved, but particle surface roughness increases which reduces fillability
Solution Approach 1:
The invention modifies the chemical composition parameters by introducing specific elements (Si, B, Al, Ga, In, La, Ce, Pr, Nd, Dy, Ho, Er, Tb, Mn, Fe, Co, Ni, Cu, Zn, Ag, Pd, Pt, Au, Hf, Ti, V, Nb, Ta, Mo, W, Re, Os, Ir, Pt, Au) into the alumina starting material. This changes the crystal growth kinetics and surface energy during nitridation reduction, allowing high crystallinity AlN to form with smooth surfaces. The incorporated elements act as growth modifiers that prevent excessive surface roughness while maintaining the high thermal conductivity associated with high crystallinity.
Solution Approach 2:
The incorporated elements (Si, B, Al, Ga, In, La, Ce, Pr, Nd, Dy, Ho, Er, Tb, Mn, Fe, Co, Ni, Cu, Zn, Ag, Pd, Pt, Au, Hf, Ti, V, Nb, Ta, Mo, W, Re, Os, Ir, Pt, Au) act as intermediary substances during the nitridation reduction process. These elements mediate between the alumina starting material and the final AlN product, controlling the reaction kinetics and surface morphology. They facilitate the formation of high crystallinity AlN while simultaneously smoothing the particle surfaces, thus resolving the contradiction between thermal conductivity and fillability.
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 resulting spherical AlN particles exhibit improved fluidity and fillability within resins, enabling their effective use in thermal interface materials for enhanced heat dissipation applications.
Implementation Method 1
supplying spherical granules of alumina (Al2O3) powder or alumina hydrate (Al2O3·nH2O) powder as a starting material to a reduction nitridation process for performing reduction nitridation
Implementation Method 2
heat dissipation materials include the line of materials called 'thermal interface materials' (below, simply referred to as 'TIMs')
Data Source
AI summary
Aluminum nitride particles which are excellent in high thermal conductivity and useful as a filler for a heat dissipating material and which have good fluidity for improving the fillability, that is, spherical AlN particles containing Zr atoms with respect to Al atoms in an amount of a molar ratio Zr/Al=4.0×10−4 to 4.2×10−2, having an AlN conversion rate of 70.0% or more, and having a circularity of 0.85 to 1.00.