Application Type Bond 1 Part or 2 Part 2 Part Material Form Gel, Silicone elastomer Industry Cooler Device , Heat Sink, PCB system assemblies, Consumer devices Manufacturer Dow Chemistry Silicone elastomer, Polydimethylsiloxane matrix Cure Method Heat, 2-Part Cure Cure Temperature (°C) 20 to 25, 100, 125, 150, 120 Cure Time (min) 10,080, 3.50, 2.50, 1.90, 30 Viscosity (cPs) Low, 6,700, Good Flowability, Thin Bond Line Thicknesses (BLTs) Color Gray Ozone Resistance Ozone resistance Chemical Resistance Good High Temperature Resistance (°C) 150 Low Temperature Resistance (°C) -45, -55, Low thermal resistance Other Resistance Low Thermal Resistance Key Specifications UL (Underwriters Laboratory), ULC (Underwriters Laboratories of Canada), NFPA (National Fire Protection Association): UL 94: UL V-0 recognized
Technical Data for Dow Dowsil SE 4430 A & B
- Adhesive - Bond
1 Part or 2 Part
- 1 Part or 2 Part - 2 Part
- Elastomer - Silicone elastomer
- Other - Polydimethylsiloxane matrix
- Silicone - Silicone elastomer
- Dispenser - Automated meter-mix
- Brush - Manual
- 2-Part Cure
- UL (Underwriters Laboratory), ULC (Underwriters Laboratories of Canada), NFPA (National Fire Protection Association): UL 94: V0 - UL V-0 recognized
Cure Temperature (°C) 20 to 25, 100, 125, 150, 120 Test Method Cure Time (min) 10,080, 3.50, 2.50, 1.90, 30 Test Method Viscosity (cPs) Low, 6,700, Good Flowability, Thin Bond Line Thicknesses (BLTs) Test Method Work / Pot Time (min) 120 Test Method Mix Ratio 1:1
Tensile Strength (psi) 620
Ozone Resistance Ozone resistance Chemical Resistance Good UV Resistance UV resistance High Temperature Resistance (°C) 150 Test Method Low Temperature Resistance (°C) -45, -55, Low thermal resistance Test Method Other Resistance Low Thermal Resistance
Dissipation Factor 0.00200, 0.00020 Test Method Filler Thermally Conductive Fillers Dielectric Strength (V/mil) Durable, 454 Dielectric Constant 4.60, 4.60 Test Method Thermal Conductivity (W/m°K) High, 0.96, 1.10 Test Method Volume Resistivity (O) 1.9E+14 (Ohm-cm)
Elongation (%) 400 Shore OO Hardness 70 Durometer Flexibility Soft
Specific Gravity 2.230 Test Method Coefficient of Thermal Expansion (CTE) 175 (ppm/ºC) Test Method
Shelf Life Details Shelf life is indicated by the “Use By” date found on the product label. For best results, Dow Corning thermally conductive materials should be stored at or below the maximum specified storage temperature. Special precautions must be taken to prevent moisture from contacting these materials. Containers should be kept tightly closed and head or air space minimized. Partially filled containers should be purged with dry air or other gases, such as nitrogen. Any special storage and handling instructions will be printed on the product containers. Shelf Life Type From date of manufacture Shelf Life (mon) 8
Not Good For
Don't Use With Non-reactive metal substrates, Non-reactive plastic surfaces, Teflon, Polyethylene, Polypropylene
Best Practices for Dow Dowsil SE 4430 A & B
All surfaces should be thoroughly cleaned and/or degreased with solvents such as Dow Corning® brand OS Fluids, naphtha, mineral spirits, or methyl ethyl ketone (MEK). Light surface abrasion is recommended whenever possible, because it promotes good cleaning and increases the surface area for bonding. A final surface wipe with acetone or IPA is also useful to remove residues that may be left behind by other cleaning methods. On some surfaces, different cleaning techniques will give better results than others. Users should determine the best techniques for their applications.
MIXING AND DE-AIRING Upon standing, some filler may settle to the bottom of the liquid after several weeks. To ensure a uniform product mix, the material in each container should be thoroughly mixed prior to use. Two-part materials should be mixed in the proper ratio either by weight or volume. The presence of light-colored streaks or marbling indicates inadequate mixing.
Automated airless dispense equipment can be used to reduce or avoid the need to de-air. If de-airing is required to reduce voids in the cured elastomer, consider a vacuum de-air schedule of >28 inches Hg (or a residual pressure of 10-20 mm of Hg) for 10 minutes or until bubbling subsides.
PROCESSING/CURING Cure rates are rapidly accelerated with heat (see heat-cure times in Typical Properties table). Addition-curing materials contain all the ingredients needed for cure with no by-products from the cure mechanism. Deep-section or confined cures are possible. Cure progresses evenly throughout the material. These materials generally have long working times.
POT LIFE AND CURE RATE Cure reaction begins with the mixing process. Initially, cure is evidenced by a gradual increase in iscosity, followed by gelation and conversion to its final state. Pot life is defined as the time required for viscosity to double after Parts A and B (base and curing agent) are mixed.
To ensure maximum bond strength for elastomers and adhesives on a particular substrate, 100 percent cohesive failure of the adhesive in a lap shear or similar adhesive strength is needed. This ensures compatibility of the adhesive with the substrate being considered. Also, this test can be used to determine minimum cure time or to detect the presence of surface contaminants such as mold release agents, oils, greases and oxide films.
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Cure Temperature Test Methods
|Cure Temperature||Cure Time Test Method|
|20 to 25°C|
|100°C||Time to 90 percent of final hardness and adhesion or 90 percent of curve height for elastic modulus, additional time may be required for the part to warm to near oven temperature.|
|125°C||Time to 90 percent of final hardness and adhesion or 90 percent of curve height for elastic modulus, additional time may be required for the part to warm to near oven temperature.|
|150°C||Time to 90 percent of final hardness and adhesion or 90 percent of curve height for elastic modulus, additional time may be required for the part to warm to near oven temperature.|
Cure Time Test Methods
|Cure Time||Test Method|
|30 min||Heat Cure|
Viscosity Test Methods
|Thin Bond Line Thicknesses (BLTs)|
Work / Pot Time Test Methods
|Work / Pot Time||Temperature|
High Temperature Resistance Test Methods
|High Temperature Resistance||Test Method|
Low Temperature Resistance Test Methods
|Low Temperature Resistance||Test Method|
|Low thermal resistance|
Dielectric Constant Test Methods
|Dielectric Constant||Test Method|
Dissipation Factor Test Methods
|Dissipation Factor||Test Method|
Thermal Conductivity Test Methods
Coefficient of Thermal Expansion (CTE) Test Methods
|Coefficient of Thermal Expansion (CTE)||CTE Test Method|
|175 (ppm/ºC)||(Linear CTE)|
Specific Gravity Test Methods
|Specific Gravity||Test Method|