High power LED encapsulation adhesive is introduced
LED encapsulation adhesive is the floorboard of the organic silicone materials LED optoelectronic industry. Due to the ozone resistance of epoxy weaker, so that the colloid yellow influence pervious to light effect, and silicone material has excellent properties such as resistance to atmospheric aging, ultraviolet aging, the epoxy resin in the high-end product application has replaced by LED silicone material.
A classification, LED encapsulation adhesive
1, according to the types of molecule chain group points: can be divided into organic silica gel and phenyl methyl is organic silica gel. Currently on the market of LED photoelectric is most widely used by the department of methyl organic silica gel, phenyl series organic silicon due to the high cost, only used in the field of high demand.
2, can be divided by using field points: LED lamp bead encapsulation with organic silicone potting with silica gel and LED application products. LED lamp bead encapsulation with organic silicone including filling silicone lens and the LED crystal solid silica gel, LED application products by potting silicone price is lower, as long as it is waterproof, such as LED potting silicone water low lamp, solar LED lamp sealing silicone, LED display screen protection transparent silica gel silica gel, LED module, etc.
3, according to the curing conditions: type can be divided into high temperature vulcanization silicone LED with room temperature vulcanized silicone type LED. When no matter which kind of type of silica gel, curing exothermic phenomenon didn't happen. High temperature vulcanization silicone is high molecular weight of polysiloxane (molecular weight average of 40 ~ 800000), room temperature vulcanized silicone rubber with low average molecular weight (3 ~ 60000), the molecular chain ends (sometimes in the middle has) with one or two functional groups, under certain conditions (the moisture in the air or proper catalyst), these functional group can react, so as to form a crosslinked structure with high molecular weight.
Room temperature vulcanized silicone rubber can be divided by the mechanism of sulfide condensation type and molding; According to the packaging methods can be divided into two components and two types of single component.
Second, the silica gel used frequently encountered problems
1. The surface wrinkling after curing
This is because the contraction caused by, for the most part because adding a solvent silicone rubber, suggested in glue to try.
2. Interface layer
This problem is caused, because the glue will be the interface between any two kinds of different material, the only way to solve it is to only use the principle of similar material to close, when cannot change another material, change of silica gel and its affinity.
3. The phosphors are precipitated
Rule out is the problem of powder, then appear this kind of circumstance of glue can be room temperature type, because in order to maintain the transmission of light in the silica gel, refractive index, etc., so can't add any suspending agent, the friends can try these problems with temperature curing products, can solve this problem.
4. After curing surface not smooth enough
This is because the glue with S, P, such as poisoning, need to clean the mold series tools such as.
Third, performance characteristics
LED is the basic structural unit of silica gel products made of silicon, oxygen link, side chain is through the silicon atoms connected to a variety of other organic groups.
Therefore, in the structure of the high power LED silicone products containing both "organic groups", and "inorganic structure", the special composition and molecular structure to make it combines the characteristics of organic matter and inorganic matter functions in one. Compared with other polymer materials, LED silicone products, the most outstanding performance is:
1. The heat resistance properties
LED silicone product is silicon (Si - O - oxygen key chain structure, C - C key in the key to 82.6 kcal/mol, Si - O can key in the key in the silicone LED to 121 kcal/mol, so LED silicone products with high thermal stability, high temperature (or radiation exposure) molecular bonds do not broken, do not break down. High-power LED silicone not only resistant to high temperature, and also good low temperature resistance, can be used in a wide range of temperatures. Chemical properties and physical and mechanical properties, along with the change of temperature are small.
2. The weather
LED silicone products, main chain - Si - O -, no double bonds exist, therefore not easy by uv and ozone decomposition. High-power LED silica gel is better than other high polymer materials, thermal stability and resistance to radiation and weather resistance ability. LED the service life of the natural environment in silica gel can be up to several decades.
3. Electrical insulation performance
LED silicone products have good electrical insulating properties, the dielectric loss, voltage resistance, arc resistance, corona resistance, volume resistivity and surface resistivity of all came out on top in the insulation material, and their electrical performance is affected by temperature and frequency is small. As a result, they are a kind of stable electric insulation material, is widely used in electronics, electrical industry. LED silicone besides has excellent heat resistance, but also has excellent water repellency, which is using electrical equipment in wet conditions with high reliability.
4. The physiological inertia
Polysiloxane compounds are known to one of the most inactive compounds. They are very resistant to biological aging, and the animal body without rejection, and has good anticoagulant capability.
5. Low surface tension and low surface energy
The main chain of the high power LED silicone is very soft, the intermolecular force is much weaker than hydrocarbons, therefore, than with low molecular weight hydrocarbons viscosity, surface tension, surface energy is small, film forming ability. This kind of low surface tension and low surface energy is the main reason why it for various applications: hydrophobic, foam, foam stability, adhesion, lubrication, polishing, and other excellent performance.
----------Archled Technology Co.,Limited