Silicone Gel and Epoxy Resin are the two most common types of materials in electronic packaging, sealing, thermal conductivity, protection and other applications. They are widely used in LED packaging, sensor sealing, power module, circuit board protection, automotive electronics, communication equipment, medical electronics and other fields.
But many engineers in the selection, often the difference between these two materials is not clear enough: which is more suitable for high temperature environments? Which is softer, more resistant to yellowing? Today we will recommend four dimensions from the material characteristics, application scenarios, advantages and disadvantages, selection, comprehensive comparison of these two types of adhesive materials, help you choose adhesive science, improve product reliability!
Organic Silicone Gel VS Epoxy Resin
What is an organic silicone gel?
Organic silicone gel is a high softness, good elasticity, deep curing silicone-based material, usually used as a dual component (A / B component) to form a soft gel-like structure after curing by room temperature or heating.
Features Overview:
Transparent or semi-transparent, low modulus
Self-healing, good stress release
UV resistance, aging resistance, high and low temperature (-60 ℃ ~ +200 ℃)
Strong electrical insulation, some models have thermal conductivity
What is epoxy resin?
Epoxy resin is a thermosetting material, used by resin and curing agent mixed, after curing to form a high strength, high hardness solid state structure. Widely used in electronic packaging, structural bonding, circuit protection, mold manufacturing and other fields.
Features Overview:
High mechanical strength and hardness
Stable volume after curing, resistant to chemical corrosion
Excellent high temperature resistance (generally up to 130 ℃ ~ 180 ℃)
Excellent electrical insulation and adhesion
III. Organic Silicone Gel Vs Epoxy Resin Comparison Table
Comparison Dimensions Organic Silicone Gel Epoxy Resin
Appearance/Hardness Soft, gel-like, good elasticity Hard, solid, high strength
Curing method Two-component, constant temperature or heating curing Two-component, heating/constant temperature curing required
Thermal conductivity Adjustable, 0.2 ~ 3.0 W/m·K, elastic thermal conductivity Adjustable, 0.5 ~ 1.5 W/m·K, structural thermal conductivity
Electrical insulation Excellent, resistant to arc breakage, suitable for precision protection Excellent, suitable for high voltage area sealing
Temperature resistance Excellent, high temperature (200 ℃) and low temperature (-60 ℃) Good, general use temperature ≤ 180 ℃
Softness / stress release Very good, strong self-healing, suitable for protecting fragile devices Harder, easy to cause stress impact on components
Curing shrinkage rate Very low, almost no shrinkage There is a certain shrinkage (about 1-3%)
UV / yellowing resistance Excellent, long-term discoloration General, some models are prone to yellowing
Process adaptability High requirements for spot glue equipment, adhesion is not strong Easy to operate, high adhesion strength after curing
Suitable for scene Flexible protection, stress buffer, encapsulated LED, MEMS chip Rigid structure, pressure-resistant encapsulation, power module, plug-in seal
Practical Application Examples
✅ Typical applications of silicone gel:
LED bead package: transparent, soft, not yellowing, suitable for optical applications
Sensor package: protects sensitive cores (e.g. magnetic cores) from stress damage
Automotive ECU flexible sealing: resistant to cold and heat shock, good stress release
Silicone thermally conductive interface material: soft fit between chip and radiator
✅ Typical applications of epoxy resin:
Power module sealing: pressure-resistant, moisture-proof, high mechanical strength
Electric vehicle controller package: high temperature operation, rigidity protection
Relay/Connector Sealing: Structural Fixing and Insulation Protection
Coil/transformer protective coating: high adhesion and thermal stability
Which one should I choose? – Use Scenario Judgment Suggestions
Conditions of use Recommended glue Reasons
High temperature + high humidity + UV aging environment Organic silicone gel Excellent weather resistance, soft coating is not easy to age
Requires structural fixation and strength support Epoxy resin High bonding strength, high hardness after curing
Precision component packaging, can not withstand hard stress Organic silicone gel Soft self-healing, release mechanical stress, protect components
Electrical equipment, motors, power modules Epoxy resin Good insulation, good mechanical properties, good heat resistance and anti-aging performance
Optical devices, LEDs, transparent packaging Organic silicone gel Optical transparency without discoloration, suitable for photoelectric modules
Cost control, simple process Epoxy resin Raw materials are cheap, curing cycle can be controlled, suitable for large-scale production
In modern electronics, no adhesive can “eat all the field”. Silicone gel and epoxy resin have advantages, the key is to make scientific choices according to the complexity of the product structure, working environment, stress conditions, electrical performance requirements and process adaptability.
If your products have high requirements for stress resistance, anti-aging, and flexible sealing, it is recommended to give priority to silicone gel; and when bonding strength, structural stability, and electrical insulation are the first considerations, epoxy resin is still the main material.
Tags: gel material selection guide · Difference between organic silicone gel and epoxy resin · Flexible filling material · What kind of filling adhesive is good · Difference between epoxy and silicone
