Are you hesitant about choosing a UV curable silicone for your project, but you don’t know enough about it? This article will serve as a comprehensive guide, analyzing the properties, advantages, and types of UV curable silicone to help you make the right choice for your project.
What Is UV Curable Silicone?
UV curable silicone is a material that can be rapidly cured under ultraviolet light. It is widely used in electronic packaging, optical bonding, sealing, and precision assembly in automated industrial manufacturing. Compared to traditional heat-cure silicone, it offers faster curing times, is compatible with heat-sensitive materials, and exhibits exceptional flexibility, transparency, and environmental resistance.
Properties of UV Curable Silicone
Optical Performance
UV curable silicone has a high transmittance, which means that when you use it in lighting fixtures, it can produce brighter and more energy-efficient results. At the same time, UV curable silicone absorbs less light energy, which can prevent related components from overheating and effectively extend the life of the light source.
Ordinary glue will turn yellow when exposed to sunlight for a long time, but UV curable silicone is engineered for extreme stability. It maintains superior optical clarity even after extended accelerated aging protocols and under extreme thermal conditions. This ensures that the aesthetic appeal of your products remains entirely unaffected throughout their entire lifecycle, thereby significantly reducing the likelihood of customer complaints.
If you intend to use silicone materials for lens module assembly, selecting a UV curable silicone adhesive is essential, because a mismatch between the adhesive and the lens can compromise imaging quality. Since the refractive index of UV silicone is fully adjustable, it can be engineered to perfectly match your specific lens. This eliminates optical distortions, providing your customers with an excellent experience.
Environmental Stability
Like regular silicone, UV curable silicone can withstand temperatures from -50°C to 200°C, and will not become brittle or crack even under large temperature changes.
If you use UV curable silicone on offshore equipment, it will maintain stable performance even if the equipment is exposed to humid air with high salt concentration for a long time.
The chemical inertness of silicone also allows it to be used in environments where it may come into contact with machine oil and cleaning agents. It will not swell or dissolve, so it will not cause the encapsulation function to fail.
Mechanical Properties
UV curable silicone is widely used in electronic products. For the same electronic product, the required hardness levels for the material vary depending on the assembly location. From the ultra-soft gel surrounding the battery to the high-hardness sealing rings at the connection ports, UV curable silicone can meet the diverse needs of different parts of the entire product.
If you wish to ensure that a foldable-screen device can withstand the frequent bending during daily use without cracking or shattering, UV curable silicone is an excellent choice. It can absorb physical impacts during collisions and bending, preventing product damage.
The high-precision chips inside electronic devices are extremely fragile. We recommend that you use UV curable silicone during assembly. The extremely low shrinkage rate of UV curable silicone prevents it from pulling on wires or warping chips during the curing process, making it convenient for assembling electronic devices.
Electrical Insulation & Flame Retardancy
Even if you use UV curable silicone as an extremely thin layer on high-voltage equipment, it can withstand high-voltage breakdown. In addition, the self-extinguishing property of UV curable silicone means it will not become a fuel source even in a flammable environment.
If you are looking for an encapsulating material that will not interfere with high-frequency signals, UV curable silicone is a good choice, as its low conductivity ensures stable high-speed communication.
Advantages of UV Curable Silicone
Chemical & Thermal Stability
Ordinary adhesives used in electronic devices with sensors can easily swell or dissolve when exposed to industrial detergents or high-temperature machine oil, leading to seal failure. However, if you use UV curable silicones as the sealing material, their thermal stability and corrosion resistance will ensure stable readings throughout the sensor’s lifespan, without short circuits or signal loss, thereby enhancing your competitiveness in the industry.
Design Flexibility
If your project involves the electronic assembly of cameras, UV curable silicone offers design flexibility to achieve complex designs. During precision assembly, engineers use UV lamps to achieve millisecond-level tack-free curing, which locks the position of precision parts with instantaneous curing. This expansive scope for design creativity, combined with shortened R&D cycles, helps your clients to achieve a diverse range of design outcomes.
In addition, the camera components of precision electronic devices are mostly made of heat-sensitive plastics. If you accidentally use traditional heating and curing methods, it can easily cause the plastic to deform, thus affecting the focus. However, the curing process of UV curable silicone does not require heating, so you can safely apply it to lightweight, heat-sensitive materials.
Sustainable Production
If you’re struggling to choose a material due to today’s trend towards sustainable development, UV curable silicone’s environmentally friendly advantages make it an excellent choice. Firstly, the changes brought about in the production process are significant. Without industrial tunnel ovens, the reduction in energy consumption demonstrates the advantages of energy saving. Secondly, the material has zero solvent evaporation (Zero VOCs). The factory also does not need to be equipped with an expensive waste gas recovery (VOCs) treatment system.
Therefore, it helps your project easily pass ISO 14001 environmental certification and meet the high-level export access thresholds of EU REACH/RoHS.
UV Curable Silicone vs. Traditional Heat Cure Silicone
Curing Speed
The traditional curing process of silicone requires waiting for the oven to preheat, then baking it in the oven for 30 minutes or even longer, and then cooling it after it comes out of the oven. Your production line requires a huge storage area to wait for the products to cool or solidify.
LED UV curable silicone is ready to use immediately, without the need for long preheating like an oven. Moreover, it can be fully cured in 3-5 seconds under a UV lamp, allowing the product to proceed directly to the next stage. For your project, this means faster lead times and reduced inventory accumulation.
Heat Sensitivity
If you are purchasing silicone for high-precision electronic components, such as assembling smartphone lenses or for flexible circuit boards, these devices cannot withstand prolonged high-temperature baking. If you choose traditional curing silicone, its vulcanization process will cause these materials to deform, affecting product performance.
UV curable silicone is a cold-curing silicone. For these special components, LED-UV can be used. UV curable silicone is cured with a cold light source, which generates almost no heat. Even when operating in close contact with precision components, the parts will not be affected.
Therefore, please note whether your project includes heat-sensitive materials; if so, UV curable silicone will be the most suitable choice.
Energy and Space Efficiency
Traditional thermosetting silicone requires time to solidify from a liquid state, which necessitates that the factory provide sufficient space to accommodate the silicone as it cools. What’s more, the industrial ovens used for traditional silicone production need to be kept running 24 hours a day to maintain the temperature, which means high power consumption and high production costs.
In contrast, the advantages of UV curable silicone are significant. The UV lamp assembly used has a small footprint and can be used immediately upon application. This will free up more space for new production lines and save a lot on electricity costs.
One-Component Reliability
Traditional heat-curable silicone requires workers to mix raw materials in a specific ratio. If the ratio is slightly incorrect, the entire batch of silicone will fail to cure. Furthermore, once mixed, the silicone must be consumed within two hours. Then any unused material must be discarded.
UV curable silicone does not require mixing and will never solidify without exposure to light. This characteristic eliminates the risk of errors in manual mixing and reduces the risk of material failure, which results in minimal material waste, saving you high costs for your project.
Quality Control
You cannot know whether the temperature inside the oven is stable or uncontrollable. If curing is incomplete, the issue often goes undetected until days later during the next processing stage, or even worse, not until you receive a complaint from a customer.
By adjusting the UV lamp and conveyor belt speed, you can precisely control the curing energy of your UV curable silicone down to the millisecond. This ensures that the curing degree of each of your products is 100% consistent, which will alleviate many of your concerns.
Types of UV Curable Silicones
UV Silicone Adhesives & Sealants
Because UV curable silicone has excellent wetting and adhesion properties, it can bond silicone tightly to metals, plastics, or glass. For example, in medical devices, when used in intravenous catheters or breathing masks, the silicone tubing can be quickly attached to a plastic connector.
Furthermore, when used as a sealing ring, its exceptional flexibility prevents cracks or leaks at the bonding point even during frequent bending of the catheter, ensuring medical safety. Therefore, UV curable silicone provides reliable protection for your projects.
UV Silicone Conformal Coatings
It can also be used as a low-viscosity protective material to form a protective film on the surface of a circuit board. You can apply it to PCBs installed near the engine compartment or chassis. Due to the inherent chemical inertness of silicone, it safeguards sensitive components against extreme environments involving oil contamination, moisture, and salt spray.
UV Silicone Potting & Encapsulants
Thanks to the excellent flowability of UV curable silicone, when used to wrap outdoor equipment and as a potting material for industrial sensors, it can provide comprehensive filling and support with its extremely high flowability, making it both waterproof and shockproof to protect the delicate internal components of the equipment.
UV Silicone Gels
UV curable silicone can also become an ultra-soft material after curing, protecting extremely tiny and fragile bond wires. When applied in semiconductor & MEMS, the gel-like UV curable silicone can absorb all external forces like a shock-absorbing cushion when the device is dropped or expands due to heat, providing the best protection for high-value electronic products.
Dual-Cure UV Silicones
Dual-Cure UV silicone is a composite material specifically designed to address blind spots where light cannot reach, which features two curing mechanisms—V + moisture and UV + heat. You can use this material in a complex industrial component. The exterior can be cured by exposure to UV light, but the interior cannot be directly exposed to UV light. In this case, the dual-cure UV silicone applied inside cures by absorbing moisture from the air within 24 hours.
Applications of UV Curable Silicone
Electronics & Microelectronics
UV curable silicone can be used to reinforce some small components, such as internal components of smartphones, chips on motherboards, or connectors. Traditional heat-curing methods can easily cause the board to curl due to heat, while UV curable silicone can cure instantly after dispensing, eliminating concerns about heat-damaging components.
Automotive Industry
If your product is used in the automotive industry, then UV curable silicone is a great choice. Automotive components are frequently exposed to diverse environments such as high temperatures, vibrations, and salt spray during use. By providing comprehensive sealing for driving system sensors, coupled with silicone’s inherent resistance to aging and cracking, UV curable silicone ensures signal accuracy and guarantees operational safety.
In addition, the radar and cameras installed in vehicles need to withstand heavy rain, high-pressure water guns used in car washes, and winter de-icing agents for extended periods. The waterproof and shock-absorbing properties of UV curable silicone can play a significant role in these applications.
Medical Device Assembly
UV curable silicone is also an essential material in the assembly of medical devices.
The flexible silicone tubes are bonded to the heat-sensitive plastic connectors, with stringent requirements regarding their resistance to deformation due to heat. UV curable silicone’s cold-curing properties protect precision optical instruments and plastic parts from heat damage.
In addition, silicone meets ISO 10993 biocompatibility certification, and its extremely high cleanliness ensures medical safety.
Optical & Display Technology
In the field of optical devices, if lenses undergo displacement during assembly due to the curing process, it can result in a focus shift. By choosing UV curable silicone for instant curing, you can achieve perfect assembly results and greatly reduce the scrap rate of your products.
Energy & Industrial Automation
Equipment intended for long-term outdoor use needs to be resistant to ultraviolet radiation and possess outstanding high insulation reliability under high-voltage conditions. UV curable silicone offers excellent dielectric strength and weather resistance, and its flame-retardant protection in case of failure prevents accidental escalation, thereby saving you on operation and maintenance costs.
FAQ
Does Rapid Curing Cause the UV Curable Silicone Adhesive to Become Brittle? Will It Crack Under Vibration?
No. Unlike UV resin, UV curable silicone is still an elastomer in essence. It retains excellent flexibility and extremely high tensile strength even after rapid curing. In high-frequency vibration applications such as automotive sensors and handheld devices, it can even act as a shock absorber, and it will never become brittle and crack as easily as ordinary glue or resin.
How Can I Determine If My Product Is Fully Solidified?
In practice, we recommend that you perform a surface dryness test. The method is to touch the surface with a cotton swab to see if it is sticky. If it is not sticky, it is considered qualified. We also recommend a hardness test, using a Shore durometer to verify that the material has reached the target hardness value. Before mass production, you can ask the factory to provide you with a set of energy density recommendations for your specific product. You only need to ensure that the output power of the UV lamp is within this range to guarantee that the quality of each batch is completely consistent.
Are UV Curable Silicone Products Subject to Stringent Storage Requirements? Will they Spoil During Transportation?
The advantage of UV curable silicone is that it does not react when exposed to light. Simply keep it away from light, heat, and moisture, and store it in a cool warehouse at around 25°C. To prevent accidental light leakage during transportation, we recommend that the original packaging container be sealed with a thickened black plastic layer. So the stability of this material means you can stockpile them like any other material, without worrying about sudden supply chain disruptions causing cold storage to be overwhelmed.
Final Thoughts
UV curable silicone is now widely used in many fields. Its outstanding advantages include chemical and thermal stability, design flexibility, and sustainable production, making it the perfect material for your project. As a silicone product manufacturer with over 20 years of history, we can provide you with high-quality silicone materials and one-stop service. If you have any questions, please contact us immediately for consultation!
