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Product Information Electronics Encapsulants Sylgard 170 Silicone Elastomer FEATURES & BENEFITS Two-part, 1:1 mix, black, general purpose encapsulant with good flowability, long working time and flame resistance Low viscosity Long working time Room temp or heat accelerated APPLICATIONS cure Sylgard 170 Silicone Elastomer is suitable for use as an encapsulant or Moderate thermal conductivity potting material. UL 94V-0 and Mil Spec tested to Potential applications: MIL-PRF-23586F (specifically Power supplies listed material numbers only) Connectors Enahanced flow and fill in narrow Sensors spaces and around complex Industrial controls geometries Transformers Rapid, versatile cure processing Amplifiers controlled by temperature High voltage resistor packs Provides stress relief in Relays applications where hard, rigid encapsulants can cause damage TYPICAL PROPERTIES during thermal cycling Specification Writers: These values are not intended for use in preparing Can be considered for uses specifications. Please contact your local Dow Corning sales office or your Global requiring added flame resistance Dow Corning Connection before writing specifications on this product. and Mil Spec applications Property Unit Result COMPOSITION Mix Ratio - 1:1 Two-part 1:1 mix ratio Color (Part A) - Black Polydimethylsiloxane silicone Viscosity (Part A) cP 3160 elastomer Pa-sec 3.1 Viscosity (Part B) cP 1110 Pa-sec 1.1 Viscosity (Mixed) cP 2135 Pa-sec 2.1 Specific Gravity (Uncured Part A) - 1.37 Specific Gravity (Uncured Part B) - 1.37 Thermal Conductivity btu/hr ft degf 0.277 w/mK 0.48 Working Time at 25C (Pot Life - minutes) minutes 15 Cure Time at 25C hours 24 Heat Cure Time at 70C minutes 25 Heat Cure Time at 100C minutes 10 TYPICAL PROPERTIES (Continued) Property Unit Result Durometer Shore A - 47 Dielectric Strength volts/mil 472 kV/mm 18 Volume Resistivity ohm *cm 5.6E+17 Dielectric Constant at 100 Hz - 2.54 Dielectric Constant at 100 kHz - 2.50 Dissipation Factor at 100 Hz - 0.002 Dissipation Factor at 100 kHz - 0.0002 Linear CTE (by TMA) ppm/ C 275 manufacturing environments and conditions for each product are given DESCRIPTION allows for some process and dispense in the product selection table. Two- Dow Corning brand silicone equipment variation. In most cases part condensation cure encapsulants encapsulants are supplied as two-part de-airing is not required. should not be heat accelerated above liquid component kits with a mixed 60C (140F). ratio of 1 to 1. When liquid components are thoroughly mixed, PREPARING SURFACES the mixture cures to a flexible In applications requiring adhesion, POT LIFE AND CURE elastomer, which is well suited for priming will be required for many of RATE the protection of electrical/electronic the silicone encapsulants. For best Cure reaction begins with the mixing applications. Dow Corning silicone results, the primer should be applied in process. Initially, cure is evidenced by encapsulants cure without exotherm a very thin, uniform coating and then a gradual increase in viscosity, at a constant rate regardless of wiped off after application. After followed by gelation and conversion sectional thickness or degree of application, it should be thoroughly to a solid elastomer. Pot life is defined confinement. Dow Corning silicone cured prior to application of the as the time required for viscosity to encapsulants require no post cure silicone elastomer. Additional double after Parts A and B (base and and can be placed in service instructions for primer usage can be curing agent) are mixed and is highly immediately following the found in the information sheets temperature and application completion of the cure schedule. specific to the individual primers. dependent. Please refer to the data Standard silicone encapsulants table. require a surface treatment with a PROCESSING/CURING primer in addition to good cleaning Thoroughly mixed Dow Corning USEFUL TEMPERATURE for adhesion while primerless silicone encapsulants may be RANGES silicone encapsulants require only poured/dispensed directly into the For most uses, silicone encapsulants good cleaning. container in which it is to be cured. should be operational over a Care should be taken to minimize air temperature range of -45 to 200C This material has a UL 94 V-0 entrapment. When practical, (-49 to 392F) for long periods of flame rating. Please review UL file pouring/dispensing should be done time. However, at both the low- and QMFZ2.E40195 for more specific under vacuum, particularly if the high temperature ends of the information on the thickness ranges component being potted or spectrum, behavior of the materials tested. encapsulated has many small voids. If and performance in particular this technique cannot be used, the unit applications can become more APPLICATION METHODS should be evacuated after the silicone complex and require additional encapsulant has been Automated mixing and considerations and should be dispensing poured/dispensed. Dow Corning adequately tested for the particular end silicone encapsulants may be either Manual mixing use environment. For low-temperature room temperature (25C/77F) or heat performance, thermal cycling to cured. Room temperature cure MIXING AND DE-AIRING conditions such as -55C (-67F) may encapsulants may also be heat These products are supplied in a 1 to 1 be possible, but performance should accelerated for faster cure. Ideal cure mix ratio, which is very robust in be verified for your parts or Dow Corning and Sylgard are registered trademarks of Dow Corning Corporation. We help you invent the future is a trademark of Dow Corning Corporation. 2014 March 12 XIAMETER is a registered trademark of Dow Corning Corporation. Form No. 11-3181C-01 2013- 2014 Dow Corning Corporation. All rights reserved. 2