TIM Quantity and Application

Designing Heatsinks and Thermal Solutions for Xilinx Devices (XAPP1377)

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1.0 English

The purpose of dispensing TIM by machine or by hand is to get coverage in the contact area as close to 100% as possible. Other goals include limiting voids, minimizing BLT, and controlling over dispensing to avoid TIM spillage and runoff. How this is done depends on the material and specific application details. This is being mentioned here as something to be discussed with manufacturing partners to ensure the goals are understood and well managed. It is expected to have some TIM runoff. As long as the TIM material is not electrically conductive or corrosive, no damage is expected in lidded or lidless applications. Being non-electrically conductive or corrosive is common for most TIM materials, however not all TIM materials. As previously mentioned, the use of etching on the contact surface also helps with achieving this goal.