In thermal system design, the performance of a thermal pad(gap pad) is determined not just by its bulk conductivity, but by its rheological behavior under assembly pressure. Achieving the minimum thermal resistance without compromising PCB mechanical integrity is a critical engineering challenge.
Physicochemical Principle: Percolation and Particle Alignment Thermal pads consist of high-elasticity silicone matrices filled with conductive ceramic particles.
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Percolation Threshold: Under compression, the internal particles are forced closer together, eventually touching to form continuous heat-conduction pathways.
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Stress Relaxation: As a viscoelastic material, silicone exhibits a peak reaction force upon initial compression, which stabilizes over time. Improper formulation can lead to excessive stress relaxation, reducing interfacial intimacy and increasing contact resistance.
Industrial Application: Optimal Compression and Component Safety Lixing Composite Material offers precise compression guidelines for various hardness levels (Shore 00):
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Optimized Wetting: A 20%-30% compression ensures the pad perfectly wets the component surface, eliminating microscopic air pockets.
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Low-Stress Solutions: For sensitive FPGAs or sensors, we provide ultra-low-stress pads that reach the percolation threshold under minimal force, preventing PCB warping or solder joint fatigue.
