Applications DOWSIL™ 340 Heat Sink Compound is suitable for thermal coupling of electrical devices and PCB assemblies to heat sinks. Compound is applied to the base and mounting 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 required. It is also suitable for aircraft engines where heat sink properties are required. Dowsil 340 Heat sink compound white 100g tube