During the initial bring-up and debug stages of the design, the removal of the heatsink is a common practice. Care should be taken to prevent device damage and to ensure that the device and heatsink are properly cleansed for reassembly without compromising the thermal integrity of the system. The thermal attachment should be disassembled to avoid creating excessive uneven pressure on the device. This practice is appropriate only during the early prototyping and assembly stages, not during operation. Often, this approach is contrary to the steps that should be taken during assembly. The TIM typically forms a bond that remains after the attachment is removed, which can cause device damage if the heatsink is directly lifted. It is suggested to remove the thermal solution with a twisting motion to break this bond. At times, it is necessary to heat the heatsink to further soften the TIM material, ensuring that excessive extracting force is not applied to the device.
The TIM material should be cleaned from the device and heatsink, and new TIM should be applied prior to reapplying the thermal solution. Follow the guidelines provided by the TIM provider for proper methods of TIM removal. Consideration should be given to the solvents used during the cleaning process to ensure that corrosion or damage does not occur to the device or thermal solution. Some solvents that AMD has success with include:
- Best – Toluene
- Better – Acetone
- Better – Isoparaffinic hydrocarbon (Isopar and Soltrol)
- Okay – Isopropyl alcohol