TENSAN | A Materials Science Guide to Encapsulation Compound Selection: Classification, Performance, and Application Scenarios

In industrial fields such as electronics manufacturing, new energy, and automotive, encapsulation compounds serve as critical materials for protective packaging, directly impacting equipment reliability, service life, and environmental adaptability. This article systematically reviews the core classifications, performance differences, and scenario-based selection logic of encapsulation compounds from a materials science perspective, providing a scientific basis for engineering material selection.

Types and Characteristics of Encapsulation Compounds

Core Functions and Technical Requirements

Encapsulation compounds fulfill three primary functions by filling voids in electronic components, PCBs, or mechanical assemblies:

• Physical Protection: Resistance to vibration, shock, dust, and moisture ingress.
• Thermal Management: Optimization of equipment temperature distribution through thermal conductivity/heat dissipation.
• Electrical Isolation: Prevention of short circuits, leakage currents, and electromagnetic interference (EMI).

Mainstream Encapsulation Compound Types and Performance Comparison

1. Silicone Encapsulation Compounds

Composition: Polysiloxane backbone with organic groups such as phenyl and vinyl.

Key Advantages:

✅ Wide operating temperature range (–60°C to 250°C continuous)

✅ High flexibility and tear resistance (elongation >200%)

✅ Excellent UV and chemical resistance

Limitations: Lower mechanical strength and weaker adhesion compared to epoxy resins.

2. Epoxy Resin Encapsulation Compounds

Composition: Epoxy groups + amine/acid anhydride curing agents.

Key Advantages:

✅ Very high hardness (Shore D >80) and adhesive strength

✅ Low shrinkage (<0.1%) ensuring dimensional stability

✅ Excellent solvent resistance and moisture barrier properties

Limitations: Brittle nature; poor resistance to thermal shock cycling.

3. Polyurethane Encapsulation Compounds

Composition: Polymerization product of isocyanates and polyols.

Key Advantages:

✅ Balanced elasticity and strength (Shore A adjustable from 50 to 90)

✅ Excellent low-temperature flexibility (remains ductile at –40°C)

✅ Repairable (local damage can be refilled with secondary encapsulation)

Limitations: Poor high-temperature resistance (long-term use <120°C).

4. Specialty Encapsulation Compounds

• Thermally Conductive Types: Filled with aluminum nitride or alumina, achieving thermal conductivity of 3–5 W/m·K (e.g., in 5G base station power modules).
• Flame-Retardant Types: Incorporating aluminum hydroxide or phosphorus-based flame retardants, meeting UL94 V-0 certification (e.g., in energy storage battery pack packaging).
• Low-Density Types: Density <1.0 g/cm³, used for weight reduction in UAV flight control systems.

Conclusion

The selection of encapsulation compounds is fundamentally a precise alignment between material properties and application requirements. As emerging sectors such as new energy vehicles and AIoT devices impose higher demands on packaging materials,Tensan Co., Ltd.,remains committed to continuous material innovation, jointly driving the deployment of encapsulation products that integrate functionality, environmental sustainability, and intelligent features—serving as a key force behind industrial upgradin