How to Choose Between Silicone, Epoxy & Polyurethane Potting Glue: Ultimate Guide for Electronics Manufacturers
1. Why Potting Material Selection Matters in Electronics?
Industry data: 38% of PCB failures originate from improper encapsulation (Cite authority statistics)
Critical protection requirements:
• IP67/IP68 waterproofing
• Thermal management (5G/EV components)
• Vibration resistance (Industrial Robot Applications)
• Chemical exposure (New energy vehicle battery pack)
2. Technical Comparison: 3 Major Potting Compounds
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PROPERTY
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||||
|---|---|---|---|---|
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Temp. Range (°C)
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-60~+300
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-40~+150
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-40~+120
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|
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Thermal Conductivity
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0.2-4.0 W/mK
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0.5-1.5 W/mK
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0.1-0.3 W/mK
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|
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Vibration Absorption
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★★★★★
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★★☆
|
★★★★
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|
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Cure Speed (25°C)
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2-24 hrs
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0.5-4 hrs
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4-48 hrs
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|
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Rework Possibility
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Yes
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No
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Limited
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|
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UL94 Rating
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V-0/HB
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V-0
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HB/V-2
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3. Industry-Specific Selection Guidelines
A. New energy vehicle electronics
Battery Management System (BMS): Silicone (temperature difference 200℃+)
Car charger: Polyurethane (shock absorption + cost balance)
Motor controller: Epoxy (High rigidity + thermal conductivity 1.2W/mK+)
B. Industrial automation equipment
Servo driver: Modified epoxy (oil resistance + fast curing)
Sensor: Low viscosity silicone (porous + flexible protection)
C. Consumer electronics
Smart wearable device: Transparent polyurethane (beautiful + medium protection)
Router module: Flame retardant silicone (UL94 V-0+ Long-term stability)
4. 7 Cost-Saving Tips Without Compromising Quality
- Priority testing for curing shrinkage (<0.5% to avoid stress cracking)
- Polyurethane with added alumina is selected when the thermal conductivity requirement is <1W/mK
- Two-component room temperature curing models are used for small batch production
- When the filling thickness is >10mm, the peak heat release must be monitored
- Verify CTE match with plastic housing in advance
- The model with hydrolysis stability >5000hr must be selected in humid environment
- Test with free samples (Insert Sample Request CTA button)
5. Analysis of common customer error cases
Case 1: A PV inverter manufacturer misuses epoxy glue to cause cracking at -30 ° C
→ Solution: Use low-temperature silicone (glass transition temperature -75℃)
Case 2: Short circuit caused by poor resistance of polyurethane to moisture and heat
→ Solution: Switch to fumed silica enhanced silicone
Case 3: Medical device fails biocompatibility test after potting
→ Solution: Request the ISO 10993 certification document in advance