In thermal design, many engineers tend to choose the “softest” pad, assuming it guarantees the lowest interfacial thermal resistance. However, material hardness (Shore Hardness) and Compression Force Deflection (CFD) represent a dynamic mechanical balance that directly impacts assembly stress and long-term reliability. A thermal silicone pad with the appropriate hardness achieves perfect gap-filling at extremely low pressures while preventing mechanical stress damage to sensitive PCB components.
Mechanical & Chemical Principles: The Non-linear Relationship of Modulus and Molecular Chains Thermal silicone is a viscoelastic material. Its hardness and thermal performance are not linearly correlated, but rather stem from unique mechanical behaviors:
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The Limitations of Hardness: Shore Hardness only represents the material surface’s resistance to puncture; it does not fully reflect the overall stress when the material is compressed. Lixing utilizes precise addition-curing technology to carefully control the cross-linking density of the molecular chains, achieving a perfect combination of low hardness (e.g., Shore 00 20-30) and low outgassing.
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Compression Force Deflection (CFD): The CFD curve describes the evolution of deformation stress as the pad is compressed. Lixing’s low-hardness series generates microscopic wetting the moment it is compressed, filling micro-voids at the interface and dropping the contact thermal resistance to an extremely low level (<0.2°C-in²/W @ 20psi).
Industrial Applications: Automotive Electronics (ADAS), Smartphones, and Multi-Chip Modules (MCM) Lixing Composite Material’s high-fill, low-stress solutions are engineered specifically for sensitive electronic components:
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Automotive Cameras & LiDAR: In environments utilizing highly filled thermal ceramics, Lixing’s thermal silicone pad can channel heat to the metal housing under extremely low compression forces, significantly reducing hot spot temperatures.
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Smartphone Modules: Our low-modulus silicone pads can withstand severe vibration and thermal shock while maintaining excellent dielectric stability and stable compression force.
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