Recommendations for thermal management in systems using Intel® Boxed Mobile Processors
The recommendations are for professional system integrators building mobile PCs from industry accepted build-to-order laptops. You should have general knowledge of and experience with PC operation, integration, and thermal management. By following the recommendations, you can provide customers with more reliable PCs.
What is thermal management?
Laptops using Intel® Boxed Mobile Processors require thermal management. "Thermal management" is a properly mounted cooling solution with effective airflow to evacuate heat from the system. Thermal management keeps the processor at or below its maximum operating temperature.
Highly efficient cooling solutions rely on proper processor installation. In all laptop designs, the processor must be properly installed and attached to the laptop cooling solution.
What is active cooling?
For high-power processors, most laptops employ one of two active cooling solutions:
- Using a heatsink attached directly to the processor
- Using a Remote Heat Exchanger (RHE), which allows the heatsink and fan to be placed far from the processor
A typical laptop cooling solution is more sophisticated than a desktop system cooling solution. Limited space and varying laptop design, layout, and processor location cause laptop cooling solutions to vary greatly. In all laptops, the processor may use passive and/or active cooling methods.
Some laptop designs use the RHE design along with a passive element to increase cooling efficiency. To add a passive element, a large metal plate is usually attached to a part of the RHE design. Additional heat dissipates passively from under the keyboard.
What is a heat pipe?
Heat is transferred from the processor to an attachment block. The heat pipe is typically a hollow copper pipe containing a fluid and wicking material that runs through the attachment block. By vaporization and recondensation, heat travels through the heat pipe to the fans of a heat exchanger (heat sink). Localized airflow then moves the heat from the system.
What is thermal interface material (TIM)?
Thermal interface material (TIM) provides efficient thermal exchange between the processor and attachment block. The thermal interface material type may vary depending on the laptop manufacturer.
Proper installation of the thermal interface material is crucial. Improper installation can cause the processor to overheat. Follow the manufacturer's instructions carefully to ensure the thermal interface material makes 100% contact with the processor's exposed die and thermal solution attachment block.
Never touch the thermal interface material. Any foreign substances (such as oils from your skin or chemicals) can reduce effectiveness of the thermal contact between the processor and attachment block.
Do I need to replace the thermal interface material if I replace my mobile processor?
If you remove the mobile processor's thermal solution, you should replace the thermal interface material.
Where do I get thermal interface material?
Since each laptop has different size restrictions and thermal requirements, laptop vendors or manufacturers must provide thermal solutions. Thermal solutions are not provided for boxed desktop products.
What is a thermal sensor?
The Intel® Mobile Processors incorporate an on-die diode that monitors the die temperature (junction temperature). A thermal sensor located on the motherboard, or a standalone measurement kit, can monitor the die temperature of the mobile processor for thermal management or instrumentation purposes.
What is thermal testing?
If you are building Intel® Mobile Processor-based laptops, consult the manufacturer to determine the highest power processor your laptop will support. Most laptops support throttling, a method of slowing down the processor if it exceeds maximum operating temperature. Throttling may cause performance reductions. Do not rely on throttling to manage the processor thermal solution.
If the processor is installed correctly, and the system accommodates the power of the processor, thermal testing may not be needed. Your laptop manufacturer may still provide software utilities that help monitor the processor temperature. Intel® Mobile Processors have built-in thermal diodes, and most laptops have built-in circuitry to convert diode readings into temperatures that can be monitored. Consult your laptop manufacturer for thermal monitoring utility availability.
Using thermocouples to measure processor temperature may be impractical, as any attachment of thermocouples may compromise the thermal solution's performance.
For more information on thermal specifications, processor power specifications, or Enhanced Intel SpeedStep® Technology (EIST), refer to the processor datasheets below.
Intel® Core™2 Duo Processors and Intel® Core™2 Extreme Processors for Platforms Based on Mobile Intel® 965 Express Chipset Family Datasheet
Intel® Core™2 Duo Processor for Intel® Centrino® Duo Processor Technology Based on Mobile Intel® 945 Express Chipset Family Datasheet
Intel® Core™ Duo Processor and Intel® Core™ Solo Processor on 65 nm Process Datasheet
Intel® Pentium® Dual-Core Mobile Processor Datasheet
Intel® Pentium® M Processor with 2-MB L2 Cache and 533-MHz Front Side Bus Datasheet
Intel® Pentium® M Processor on 90 nm Process with 2-MB L2 Cache Datasheet
Intel® Pentium® M Processor Datasheet
Mobile Pentium® III Processor Datasheet
Intel® Celeron® M Processor Datasheet