top of page

Optically Clear Polymer LED Encapsulants | Clear LED Potting SI8250


Product Description

SI8250 is high purity two-component heat curing silicone materials. Primarily designed for the manufacture of optical device modules, and can be used for injection molding an optical lens and an optical waveguide coupling reduces scattering loss. Resistance to environmental pollution, moisture, shock, vibration, etc., Maintain optical properties, mechanical properties and electrical properties in a wide range of temperature, humidity and harsh environmental conditions


Key Features

1. High transparency

2. Excellent heat resistance

3. Long-term resistance to UV-A and UV-B

4. No yellowing

5. Fast curing and rapid demold

6. Extremely accurate molding effect

7. Lighter than glass

8.Excellent for protecting LEDs and solar applications



  • Optical assembly
  • Opto-electronics, photonics, LEDs
  • Optical encapsulation & glob topping, casting, potting
  • Solar panels
  • Electronics potting


Packing Specification


Part A: 0.5kg/Pot, Part B:0.5kg/Pot;

Part A:5kg/Pot, Part B:5kg/Pot.


Transport &Storage

When stored at or below 20°C dark and cool place in the original unopened containers, both Part A and Part B have a usable life of 12 months from the date of production..

It’s non-dangerous goods, can be transported as normal chemicals, CAUTION leakage during transport.


Directions for Use

1. The substrate surface should be clean and dry. The substrate can be heated to remove surface moisture. Using naphtha, methyl ethyl ketoxime (MEK), or another suitable solvent to clean the surface of the substrate. It should not use the solvent which dissolves or corrode to the substrate, should not use residual solvent.

2. Please keep accurate weigh to a clean glass container and mix thoroughly. When using high-speed mixing equipment, heat will generate and the work time will reduce.

3. Under 10mmHg vacuum extrusion bubble. Usually, prolapse bubbles before dispensing packaging material.

4. In most cases, the polysiloxane is suitable for working long hours at -45°C to 200°C, the maximum short-term resistance to 350°C, the specific use, it is best to test the actual requirements.

5. Before the uncured material, containing not touch N \ P \ S and other organic matter, cannot touch Sn \ Pb \ Hg \ Bi \ As the ionic compound, etc., cannot touch the acetylene-containing \ active vinyl compound, peroxide cannot touch the water gas and alcohols. These substances will hinder curing material reaches a certain concentration, the specific performance of three phenomena: the flow has been in a state completely cured, and the substrate base surface with thin fluid or in Las state, the contact surface and the substrate smiling bubbles. Fully test before use.

6. Should be cured by heating using a hot air oven ventilation to prevent the accumulation of trace amounts of hydrogen generated in the curing process to produce an explosion hazard.

Optically Clear Polymer LED Encapsulants | Clear LED Potting



    Part A

    Part B


    Visual inspection

    Black viscous liquid

    White viscous liquid

    Viscosity, cps , 25

    GB/T 10247-2008



    Density,,g/cm3, 25℃

    GB/T 15223-1994



    Mixture ratio

    Weight Ratio

    A:B = 100:100

    Viscosity of mixture,4#rotor,cps , 25℃

    GB/T 10247-2008


    Operation time,mins , 25℃

    GB/T 10247-2008


    Cure condition

    GB/T 10247-2008

    25℃/8 hr or 70℃/ 50mins, 80℃/ 30mins

    Characteristics after curing

    Cured appearance

    Visual inspection

    Gray elastomer

    Hardness, Shore A

    GB/T 531-2008


    Thermal conductivity,W/mK

    GB/T 10297-1998


    Linear expansion,K-1,ppm

    HGT 2625-1994


    Dielectric strength ,kV/mm, 25℃

    GB/T 1695-2005


    Volume resistance,DC 500V, Ω·CM

    GB/T 1692-92


    Loss factor(1 MHz)

    GB/T 1693-2007


    Dielectric constant(1 MHz)

    GB/T 1693-2007


    Application temperature,  ℃

    GBT 20028-2005

    - 60 ∽ 250

    Flame resistance



bottom of page