Dow DOWSIL TC-4040 Dispensable Thermal Pad

Thermal interface materials for telecom and network equipment and other advanced devices need to dissipate significant amounts of heat in 5G network and cloud computing systems. At the same time, manufacturers need material solutions that enable efficient assembly. Dow’s DOWSIL TC-4040 Dispensable Thermal Pad is a thermal interface material (TIM) that is easy to dispense, resists slumping and provides strong thermal conductivity — a key property in 5G designs with higher heat caused by greater power densities.

The two-part TIM and gap filler allow electronic designers to replace traditional, fabricated pads of various thicknesses with a single UL 94 V-0 material for dispensing or printing through a choice of manual and automated processes. It supports either room temperature or accelerated curing and delivers good thermal and mechanical performance.

The product supports automated dispensing, stencil printing and screen printing; a piston pump and plunger metering are recommended for dispensing because of the material’s high filler loading. It offers a high extrusion rate and delivers precise component coverage with needle dispensing. The high thermally conductive material (4 W/mk) has a working time of 2–4 h.

The reworkable gap filler is supplied as a two-part liquid component kit and has a shelf life of up to six months at room temperature. It has been shown to resist various harsh environmental tests, including a 1000 h ageing test at 150°C, 1000 cycles of thermal shock from -45 to 125°C and 1000-h 85/85% RH (high-temperature/high-humidity) ageing tests.