Product Information Silicon-Based Compounds Dow Corning 340 Heat Sink Compound Compound provides thermal coupling of electrical/electronic FEATURES devices to heat sinks High thermal conductivity Low bleed USES Stable at high temperatures Dow Corning 340 Heat Sink Compound is applied to the base and mounting COMPOSITION studs of transistors, diodes and silicon-controlled rectifiers. It can also serve as an effective thermal coupler for many heat sink devices where efficient cooling is Greaselike silicone fluid thickened required. It is also suitable for aircraft engines where heat sink properties are with metal oxide filler required. This product has also been used as a high-voltage corona suppressant, nonflammable coating in connections for flyback transformers and TV sets and similar applications. TYPICAL PROPERTIES Specification Writers: Please contact your local Dow Corning sales office or your Global Dow Corning Connection before writing specifications on this product. Method Test Unit Result Color White ASTM D 217 Consistency, Penetration unworked 300 worked 60 strokes 275 worked 100,000 strokes 245 Fed. Std. 791, Bleed after 24 hr at 392F (200C) percent 0.05 Method 321.2 Fed. Std. 791, Evaporation after 24 hr at 392F (200C) percent 0.5 Method 321.2 ASTM D 2265 Drop Point F (C) 570 (300) ASTM D 1475 Specific Gravity at 77F (25C) 2.1 1 CTM 0069 Thermal Conductivity, K Factor cal/sec-cm-C 0.0014 2 ASTM D 149 Dielectric Strength volts/mil 210 ASTM D 495 Arc Resistance seconds 165 ASTM D 150 Dielectric Constant, at 100 Hz 5 at 100 kHz 5 ASTM D 150 Dissipation Factor, at 100 Hz 0.01 at 100 kHz 0.02 15 ASTM D 1169 Volume Resistivity ohm-cm 2 x 10 ASTM D 4049 Water Spray Off percent 1.3 1 CTMs (Corporate Test Methods) correspond to standard ASTM tests in most instances. 2 Measured using a sample thickness of 50 mils. The compound resists changes in con- DESCRIPTION sistency at temperatures up to approxi- Dow Corning 340 Heat Sink Compound mately 350F (177C). In doing so, it is a grease-like silicone material, heavily helps maintain a positive heat sink seal filled with heat conductive metal to improve heat transfer from the oxides. This combination promotes electrical/electronic device to the heat high thermal conductivity, low bleed sink or chassis, thereby increasing and high-temperature stability. overall efficiency of the device.information should not be used in HANDLING PRECAUTIONS PACKAGING substitution for customers tests to PRODUCT SAFETY INFORMATION Dow Corning 340 Heat Sink Com- ensure that Dow Cornings products REQUIRED FOR SAFE USE IS NOT pound is available in 5-oz (142-g) are safe, effective, and fully satisfactory INCLUDED IN THIS DOCUMENT. tubes, 13.5-oz (383-g) weight/ for the intended end use. BEFORE HANDLING, READ 5.75-fl oz (170-mL) volume Semco PRODUCT AND MATERIAL cartridges, 20-lb (9-kg) pails, and Dow Cornings sole warranty is that SAFETY DATA SHEETS AND 275-lb (124.7-kg) drums for produc- the product will meet the Dow Corning CONTAINER LABELS FOR SAFE tion lines and large scale operations. sales specifications in effect at the time USE, PHYSICAL AND HEALTH All weights, net. of shipment. Your exclusive remedy HAZARD INFORMATION. THE for breach of such warranty is limited MATERIAL SAFETY DATA SHEET LIMITATIONS to refund of purchase price or replace- IS AVAILABLE FROM YOUR This product is neither tested nor ment of any product shown to be other DOW CORNING REPRESEN- represented as suitable for medical than as warranted. Dow Corning speci- TATIVE, OR DISTRIBUTOR, OR or pharmaceutical uses. fically disclaims any other express or BY CALLING YOUR GLOBAL implied warranty of fitness for a par- DOW CORNING CONNECTION. SHIPPING LIMITATIONS ticular purpose or merchantability. None. Unless Dow Corning provides you USABLE LIFE AND with a specific, duly signed endorse- STORAGE WARRANTY INFORMATION ment of fitness for use, Dow Corning Dow Corning 340 Heat Sink Com- The information contained herein is disclaims liability for any incidental or pound has a shelf life of 60 months offered in good faith and is believed consequential damages. Suggestions of from date of manufacture. Refer to to be accurate. However, because use shall not be taken as inducements product packaging for Use By date. conditions and methods of use of our to infringe any patent. products are beyond our control, this Printed in USA Dow Corning is a registered trademark of Dow Corning Corporation. Form No. 10-748B-01 AGP5223 1997, 1999, 2000 Dow Corning Corporation. All rights reserved.