Silicone Paste

Dow Corning silicone solutions for LED packages are
designed to meet the challenging needs of the LED market.
Silicone products offer good compatibility with standard LED
substrates and processing techniques. The Dow Corning
product line contains gels, elastomers and resins.


• High optical transparency
• Excellent UV resistance
• Excellent thermal stability
• Low moisture up-take
• Low ionic content


• Well-suited for IR, visible or UV
optical applications
• Lead-free solder reflow temperatures
• Flexibility in manufacturing
• Good adhesion to various lead frames

1.Encapsulants: Gel, Elastomer and Resin

Dow Corning provides both High RI and Normal RI OE
Series silicone encapsulants, which have outstanding light
transmittance across the application wavelengths of LEDs.
These encapsulants provide excellent stress relief, moisture
protection and UV resistance for LED chip sealing and

2.Lens Molding: Elastomer and Resin

Dow Corning provides the high RI resin material needed
for optical lens fabrication. These products are designed
with excellent injection and compression molding

3.Overmolding: Elastomer and Resin

Dow Corning® OE Series silicone encapsulants are
excellent candidates for the overmolding process, the leading-
edge process technology.

Material Properties of HRI Encapsulants
NRI Encapsulants
Dow Corning®
Dow Corning®
Dow Corning®
Dow Corning®
Dow Corning®
Dow Corning®
As Supplied
Component 2-part 2-part 2-part 2-part 2-part 2-part
Mixing Ratio 10:1 10:1 1:1 1:1 1:1 1:1
Cure Condition, °C/hr 150/1 125/0.5 80/1 150/1 150/1 150/1
Viscosity, Pa·s 2.1 5.4 0.5 0.35 3.4 1.5
After Cure
Hardness, JIS A - - - 35 71 65
Refractive Index 1.42 1.41 1.41 1.40 1.41 1.41
Transmittance, % @ 450 nm,
1 mm
99 91.5 100 99 97 98