Potting adhesive is widely used in electronic manufacturing and industrial packaging to protect circuits, improve weather resistance, and extend product life. With the continuous improvement of process requirements, UV sealant and epoxy sealant have become the two most common choices in the industry due to their different curing mechanisms and performance characteristics. So what are the differences between them? This article comprehensively analyzes the curing principle, physical properties, applicable scenarios, advantages and disadvantages of Yilian from multiple dimensions.
UV sealant and epoxy sealant
1、 What is UV sealant?
UV sealant is a type of UV curable adhesive, usually a single component system, that can be quickly cured by UV irradiation. Suitable for application scenarios that require high efficiency, dense components, and transparency or partial transparency.
UV sealing adhesive
Core features:
✅ Rapid curing: curing can be completed within a few seconds to minutes under UV irradiation;
✅ Good transparency: commonly used in LED packaging and optical sensors;
✅ Easy to operate: single component system, no mixing required, suitable for automated dispensing;
✅ Suitable for micro precision packaging: low viscosity, strong fluidity, suitable for filling small gaps;
⚠️ Attention: UV glue must be transparent to cure, and shadow areas cannot be completely cured. It is necessary to use a photoinitiator or adopt a dual curing system (UV+heat curing).
2、 What is epoxy sealant?
Epoxy sealant is mainly a two-component thermosetting adhesive (there are also some single component thermosetting types), which is cured through chemical reactions at room temperature or under heating conditions. It occupies an important position in industrial applications due to its excellent mechanical properties and chemical stability.
Epoxy sealant
Core features:
✅ Superior mechanical properties: After curing, it forms a hard material with impact resistance and compressive strength;
✅ Strong ability to withstand high and low temperatures: able to withstand -40 ℃~150 ℃ for a long time, suitable for industries such as automobiles and electricity;
✅ Good electrical insulation: can be applied to high-voltage modules and transformer packaging;
✅ Strong chemical resistance: suitable for protecting electronic modules in harsh environments;
⚠️ Attention: The curing time is relatively long (usually several hours), making it difficult to rework. Some materials are hard and brittle, which is not very friendly to thermal sensors.
3、 Detailed comparison between UV sealant and epoxy sealant
Project UV sealing adhesive epoxy sealing adhesive
Curing method: UV curing (with auxiliary heat/moisture curing), room temperature or heating curing
Fast curing speed (seconds~minutes) Slow curing speed (30 minutes~24 hours)
Suitable for transparent or partially transparent substrates, various metals, plastics, ceramics, PCBs, etc
Good mechanical properties, elasticity, moderate strength, high strength, and high hardness
Thermal stability is average (≤ 100 ℃) and excellent (can withstand temperatures above 150 ℃ for a long time)
Strong reworkability (erasable uncured adhesive) weak (difficult to remove after curing)
Generally excellent waterproof and insulation performance
Medium strong adhesive performance
High transparency (optical grade), moderate or opaque
Relatively high price, low cost, high cost-effectiveness
4、 Examples of application areas
Recommended adhesive types for industry categories and application examples
Consumer electronics UV sealing adhesive LED bead packaging, optical lens fixation, sensor transparent packaging
Automotive electronic epoxy encapsulation adhesive ECU packaging, power module encapsulation, ignition module moisture-proof encapsulation
Industrial equipment epoxy sealing adhesive motor sealing, transformer sealing, connector sealing
Medical Device UV/Hybrid Adhesive Small Sensor Encapsulation, Disposable Equipment Glue Encapsulation
Smart home UV sealing adhesive transparent shell components, control panel bonding
Epoxy sealing adhesive RF module, power sealing, high-frequency filtering module for communication equipment
5、 How to choose the appropriate sealant?
When choosing sealant, the following factors should be considered comprehensively:
Curing time requirement: Is it necessary to cure quickly to improve efficiency?
Packaging volume size: When the amount of glue is large, the curing depth and heat release should be considered;
Requirement for Transparency: Is it a visible component or optical part?
Environmental temperature: Is the working environment in a high temperature or large temperature difference environment?
Is it repairable: Is there a need for repair or maintenance?
Substrate compatibility: Is it suitable for metal, plastic, glass, or PCB?
6、 Summary: Choosing glue is not the “best”, only the “most suitable”
In the field of electronic sealing, UV sealing adhesive and epoxy sealing adhesive each have their own advantages. UV glue stands out in the fields of optics and microelectronics packaging due to its advantages of fast, transparent, and low-temperature curing; Epoxy sealant, with its advantages of high strength, strong weather resistance, and wide applicability, is widely used in heavy-duty scenarios such as industry and automobiles.
The correct selection of adhesive is the key to ensuring product reliability and manufacturing efficiency. If you are struggling with glue selection, please feel free to contact us for exclusive solutions and sample testing!
Tags: UV sealing adhesive · Rapid curing agent · Epoxy sealing adhesive · Electronic sealing adhesive
