1.1 Core Mechanism of Silicone Thermal Conductivity

Thermal conductive rubber is a functional material created by filling a rubber matrix with thermally conductive fillers, balancing thermal conductivity, insulation, and elasticity:

Property	Advantage
Thermal Path Construction	Fillers (Al₂O₃/BN/graphene) form conductive networks for directional heat dissipation
Interface Stress Buffer	Elastic modulus (0.5~5MPa) fills device gaps, reducing contact thermal resistance by >30%
Electrical Insulation Safety	Volume resistivity >10¹² Ω·cm, breakdown voltage >10 kV/mm
Environmental Resistance	Temperature range: -60°C~250°C, UV/ozone/chemical corrosion resistance

Silicone rubber itself is a poor thermal conductor (inherent conductivity: 0.1-0.3 W/m·K). Its thermal performance entirely depends on filler system design:

• Phonon-Dominated Heat Transfer:
  Heat propagates through non-metallic materials as lattice vibration waves (phonons). Silicone’s disordered molecular chains scatter phonons, while highly conductive fillers (e.g., AlN, diamond) establish efficient phonon pathways via regular crystal structures.
• Filler Network Construction:
  When filler volume fraction exceeds 70%, particles form interconnected 3D thermal networks, enabling rapid heat transfer along “filler chains”.
• Interfacial Thermal Resistance Optimization:
  Silane coupling agents modify filler surfaces, enhancing chemical bonding with silicone and reducing phonon scattering losses at interfaces (thermal resistance reduced by up to 50%).

Silicone remains the optimal choice due to its molecular chain flexibility, wide temperature tolerance (-50~200°C), and high filler tolerance (>90% filler content while maintaining elasticity). Other rubbers serve only as limited-scenario alternatives with significantly higher costs.

1.2 Feasibility of Thermal Conductivity in Other Rubbers

Thermal conductivity isn’t exclusive to silicone, but other rubbers face three major challenges:

Rubber Type	Thermal Potential	Technical Challenges & Solutions
Fluorocarbon (FKM)	3-5 W/m·K	High-temperature resistance (>200°C), but brittleness at high filler loads → Add CNTs + silica microspheres for toughness
EPDM	2-4 W/m·K	Low polarity causes poor filler dispersion → Use plasma-activated Al₂O₃ to enhance interfacial bonding
Nitrile (NBR)	≤2.5 W/m·K	Low heat resistance (<120°C) → Limits use of high-conductivity fillers (e.g., graphene)
Polyurethane (PU)	≤3 W/m·K (theoretical: 5W)	Microphase separation hinders heat transfer → Requires block copolymers for directional filler distribution

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1.3 Application Examples of Non-Silicone Thermal Rubbers

Product	Matrix	Conductivity	Application Scenario
Thermal FKM Seals	FKM	3.2 W/m·K	Semiconductor reactor sealing
EPDM Thermal Gap Pads	EPDM	2.5 W/m·K	EV battery module interlayer cooling
Silicone-Free PU Pads	PU	1.8 W/m·K	Medical MRI equipment (avoid silicone contamination)

2. Filler System Optimization

Conductivity (W/m·K)	Core Filler Composition	Thermal Mechanism
1-3	Al₂O₃ (70%) + silica powder	Basic particle contact conduction
5-8	BN + spherical Al₂O₃ (85%)	“Thermal chain” network construction
10-15	Diamond powder + modified graphene (90%)	Phonon transmission + lattice vibration synergy

3. Interfacial Thermal Resistance Control

• Surface Wetting Technology:
  Micro-adhesive surface layer (0.01-0.03N/cm²) fills air gaps, reducing thermal resistance by 40%.
• Adaptive Deformation:
  Ultra-soft pads (Shore00 10-30) achieve >95% contact area under 0.05MPa pressure.

4. Structural Innovation Design

Type	Technical Solution	Thermal Gain
Composite Pad	Glass fiber mesh embedding (0.2mm)	+15% conductivity
EMI-Absorbing Pad	Ferrite/CNT hybrid filler	Dual thermal/EMI function
Adhesive-Backed Pad	Acrylic PSA layer (50μm)	Assembly thermal resistance ↓30%

Thermal Silicone Pad Product Series

Product Series	Conductivity (W/m·K)	Key Features/Differentiators	Target Applications
Standard Pads	1.0/2.0/3.0	Cost-effective, basic cooling	Consumer electronics, LED
High-Performance Pads	5.0/6.0/8.0	Mid-high conductivity, balanced performance	5G base stations, PSUs
Ultra-High Perf. Pads	10.0/12.0/15.0	Extreme thermal conductivity	Server CPUs, high-power ICs
Ultra-Low VOCs Pads	D3-D20 (≤100ppm)	Ultra-low outgassing, aerospace/medical grade	Aerospace, medical devices
Silicone-Free Pads	2.0/3.0/5.0	No silicone migration, protects circuits	Optical sensors, IC packaging
EMI-Absorbing Pads	3.0/5.0	Thermal + electromagnetic absorption	RF modules, microwave devices
Low-Density Pads	1.2/2.0/3.0	Density ≤1.0g/cm³, lightweight	Wearables, drones
Ultra-Soft Pads	1.0-3.0 (Shore00 10-30)	Ultra-low hardness, fills gaps down to 0.1mm	Flexible circuits, micro-electronics
Composite Pads	Custom (2.0-8.0)	Fiberglass/PI reinforced/adhesive-backed	Industrial, high-vibration

Core Product Features

• High Conductivity & Low Thermal Resistance:
  Continuous thermal paths via ceramic/metal fillers (AlN, ZnO, diamond); optimized silicone resin reduces phonon scattering.
• Electrical Insulation & High Voltage Resistance:
  Insulated filler surfaces (e.g., Al₂O₃-coated); dense structure blocks current (withstands >10kV/mm).
• Environmental Stability:
  Platinum-catalyzed anti-yellowing; UL94 V-0 flame resistance (Al(OH)₃/P-based additives); stable from -50°C to 200°C.
• Low Oil Bleed (<0.1%):
  Ultra-high crosslinking + low-MW inhibitors.
• Reusability:
  3D network memory recovery.