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Dowsil™, Sylgard™: innovative silicones for high performance lighting

Publié le 2021-03-11

Innovations for lighting

Customers and end users demand brighter, more energy-efficient and more sustainable lighting systems. You can meet this demand and shape the future of lighting with the right materials. Do you already know about the latest innovations in lighting silicones?

DOW's innovative, high-performance silicones for optics protection and assembly will help you imagine a brighter future. Rely on the long-lasting adhesion and protection against moisture, dirt, thermal and physical damage offered by DOW silicones for protection and mounting.

In addition, DOW silicones offer superior reliability and long-lasting performance, even in the most demanding applications. Unlike traditional plastics, DOW silicones allow you to create complex-shaped optics with fine details and built-in mechanical features.

Assembly and protection solutions:

Whatever the application, your design must remain intact and protected from ultraviolet light, moisture, dust, corrosion, shock and vibration, operating heat and environmental thermal extremes. You can draw on Dow's decades of experience in encapsulating, assembling, sealing and thermally protecting sensitive devices in demanding applications, from implanted medical devices to aviation instruments, and from transportation PCB assembly to solar energy systems.

We can help you choose the right material from the following range of proven, high-performance products. These products include the following innovations in lighting silicone:

  • Adhesives and sealants
  • Clear encapsulants
  • Coatings
  • Gels
  • Thermal compounds
  • Thermal interface materials

Adhesives and sealants :

By forming durable, low-stress elastomers, DOWSIL™ silicone adhesives and sealants enable you to achieve excellent bonding and sealing between a variety of common LED lighting materials. This increases your design flexibility while providing reliable long-term performance at temperatures up to 150°C. These single-component, solvent-free materials cure at room temperature to greatly simplify processing, and their low volatility helps your design maintain light output throughout its life.

Dowsil™ 3140 RTV Coating

Dowsil™ 3165 Fast Tack RTV Adhesive Sealant

Dowsil™ 7091 Adhesive Sealant Dowsil™ 3-1944 RTV Coating Dowsil™
SE 9186 Sealant

Color

Translucent Gray White Translucent Translucent
Viscosity (cP) 34 400 Non-flow Pâteux 63 775 64 000
Extrusion Rate (g/m) N/A 212 208 N/A N/A
Specific gravity, kg/l 1,05 1.35 1.4 1.03 1.03
Tack-free time 25°C (min) 116 5 28 14 8

Durometer, Shore A

(psi)

(MPa)

32

35 32 36 20

434

125 363 325 360

3.0

0.8 2.5 2.2 2.5
Elongation, % 419 185 680 145 550
Adhesion 7.0 N/mm (180° peel strength) 1.3 MPa - 0.9 N/mm(180° peel strength) 1.3 MPa
Linear CTE, ppm/°C 325 250 - - -
Dielectric strength (Volts/mil) 385 505 400 525 -
Dielectric strength (kV/nm) 15 20 16 21 575
Volume resistivity, ohm,cm 2.10E+14 2.40E+15 1.00E+10 1.60E+15 2.00E+16
Agency listing

IPC, Mil Spec
UL 94
UL 746
UL 746C

UL94
UL94 746
UL94
UL 746
UL 746C
IPC
Mil Spec
UL 94
UL 746
-

Encapsulants:

Protection et performance vont de pair. Les encapsulants clairs de Dow vous aident à équilibrer les deux. En plus de résister à l'humidité, ils absorbent les contraintes du cycle thermique, protégeant ainsi les composants sensibles. Leur haute transmittance et leur stabilité thermique aident votre conception à maintenir la qualité de la lumière sur une plus longue période, tandis que leur chimie unique offre un jaunissement et une dégradation minimaux.

 

Grâce à une sélection de profils de durcissement, de viscosités et de duretés, vous pouvez explorer de nouvelles options de conception dans une variété d'applications. Ces encapsulants bicomposants offrent également une résistance à l'humidité, absorbent les contraintes du cycle thermique et protègent les composants sensibles.

Dowsil™ EI-1184 Optical Encapsulant

Dowsil™ EI-2888 Primerless Silicone Encapsulant

Sylgard™ 184 Silicone Elastomer

Mix ratio

1:1 1:1 10:1
Viscosity (part A), cP 4 400 2 000 5 100
Viscosity (part B), cP 3 500 2 300 -
Viscosity  (mixed*), cP 5 300 2 700 3 500
Specific gravity, kg/l 1.04 - 1.03
Cure time (min) 4 h at 25°C
70 at 50°C
<5 at 100°C
<150°C
6 h at 25°C 2 days at 25°C
35 at 100°C
20 at 125°C
10 at 150°C
Working time at 25°C (pot life), hrs 24 min - 1.5 h

Durometer, Shore A

(psi)

(MPa)

61

10 43

1 375

29 980

9.5

0.2 6.7
Elongation, % 55 190 -
Linear CTE , ppm/°C - 482.6 340

Light Transmittance

3.2 mm d'épaisseur
93% to 380 nm
94% to 450 nm
94% to 760 nm

3.2 mm Thickness
91% to 380 nm
94% to 450 nm
95% to 760 nm

-
Refractive index 1.42 à 633 nm 1,41 à 633 nm 1.4118 at 589 nm
1.4225 at 632.8 nm
1.4028 at 1321 nm
1.3997 at 1554 nm

Dielectric strenth (Volts/mil)

500 482.6 -
Dielectric strenth (kV/nm) 19 19 2.72
Volume resistivity, ohm,cm 3.50E+16 1.00E+16 2.9E+14
Agency listing UL94
UL 746A
UL 746C (f1)
UL 94
UL 746
UL 746 C (f1)
UL 94
UL 746
UL 746 C

Coating


The sensitive circuit boards in your designs need protection from moisture and physical stress. DOWSIL™ tropicalization coatings can provide this protection - and excellent insulation against shock and short circuits. They are available in a variety of viscosities and cure profiles to fit your need.

Dowsil™ 1-2577 Conformal Coating

Dowsil™ 1-2577
LOW VOC Conformal Coating

Dowsil™ 3-1944
RTV Coating
Dowsil™ 3-1953
Conformal Coating
Dowsil™3140
RTV Coating

Color

Transparent Transparent Transparent Transparent Transparent
Viscosity 950 970 63 775 350 34 400
Specific gravity, kg/l (uncured) 1.04

0.88

- - -
Specific gravity, kg/l (cured) 1.11 1.12 1.03 0.98 1.05
Heat cure (min) 2 2 N/A 0.5 N/A
Tack-free time at 25°C (pot life), (min) 7 6 14 8 116
Tack-free time at 60°C/15% RH (min) 1.3 1.5 0.5 0.5 -

Durometer, Shore A

(psi)

(MPa)

80

85 36 34 32

-

650 325 80 434

-

4.5 22 0.6 3.0
Elongation, % - 60 145 60 419
Linear CTE, ppm/°C - 250 - - 325
Dielectric strength (Volts/mil) 400 350 525 425 385
Dielectric strength (kV/nm) 16 13 21 17 15
Volume resistivity, ohm,cm 5E+13 1.90E+14 1.60E+15 5.50E+15 2.10E+14
NVC (nonvolatile content) (%) 7.23 37 - 99.4 95.7
Agency listing UL94 V-0 IPC
Mil Spec
UL 94
IPC
Mil Spec
UL 94
UL 746
IPC
Mil Spec
UL 94
UL 746E
IPC
Mil Spec
UL 94
UL 746
UL 746 C

Gels 

The gels DOWSIL™ and SYLGARD™ offer you even more design flexibility. Their softness and low stress make them ideal for devices with sensitive components and fine wiring. These two-part materials retain many of the stress relieving and self-healing qualities of a liquid while maintaining the dimensional stability of an elastomer. The gels cure in place to form a cushioning, self-healing, resilient material that relieves stress, electrically insulates and protects against moisture and other contaminants.

Dowsil™ 3-4154 
Dielectric Gel

Dowsil™ 3-4207
Dielectric Tough Gel

Sylgard™ 527
Silicone Dielectric Gel

Color

Transparent Vert translucide Transparent ou Rouge
Viscosity (part A), cP 550 425 470
Viscosity (part B), cP 525 525 454
Viscosity  (mixed*), cP 550 - 465
Specific gravity, kg/l (polymérisé) 0.97 0.97 0.95
Cure time (min) 3 h à 80°C
1.75 h à 100°C
1.5 h à 25°C
10 min à 50°C
3 min à 100°C
3.5 h à 100°C
1.25 h à 125°C
35 min à 150°C
Gel time at 25°C (min) - 9.8 -
Working time at 25°C (min) 30 10 120

Durometer, Shore 00

N/A

59 N/A
Gel hardness (g) 110 N/A 113
Penetration (1/10 mm) 50 N/A -
Linear CTE , ppm/°C - - 335
Dielectric strength (Volts/mil) 450 420 425
Dielectric strength (kV/nm) 18 17 17
Volume resistivity, ohm,cm 1.05E+15 7.10E+13 2.75E+15
Agency listing - UL 94
UL 746
UL 746C
-

Thermal compound 

The compounds offer high overall conductivity and low thermal resistance.

Dowsil™ TC-5026
Thermally Conductive Compound

Dowsil™ TC-5080 
Thermal Grease

Color

Gris Blanc
Viscosity, cP 100 000 836 000
Specific gravity, kg/l 48 2.1
Cure time àt 25°C (pot life), hrs N/A N/A
Heat cure time (min) N/A N/A

Durometer, Shore 00

(psi)

(MPa)

N/A

N/A

N/A

N/A

N/A

N/A
Elongation, % N/A N/A
Thermal Conductivity (w/mk) 2.9 1
Dielectric strength (Volts/mil) 227 220
Dielectric strength (kV/nm) 8.9 8.7
Volume resistivity, ohm,cm 5.90E+11 2.90E+15
Agency Listing - -

More information

Need information on silicones dedicated to LEDs or on brands Dowsil™ and Sylgard™  ? Contact our technical service to +33 426 680 680 or fill our contact form.

you may also be interested in : Dow Silastic Moldable Silicone: The solution for LED lens manufacturing (Adaptive Driving Beam)

Download the LED Lighting product documentation from DOW :