Intel D425KT Product Specification - Page 55

Technical Reference 2.6.1.2 Thermal Specifications Guideline Terms TA TJ ΨJA TIM TDP TA external Requirements ≤ 50 °C ≤ 100 °C ≤ 3.85 °C/W Honeywell PCM45F 13 W ≤ 35 °C 2.6.1.3 Heatsink Design Guideline Maximum heatsink size (Note) 87 x 62 x 35.54 mm Heatsink mass ≤ 80 grams Retention type Spring loaded fasteners Heatsink preload 11.3 +/- 3.6 lb Note: Refers to the heatsink installed on the board. 2.6.1.4 Chassis Design Guideline The pin fin heatsink design used on this board will be able to dissipate up to 13 W of processor power in most of the passively enabled system chassis. This board is targeted for 3-7 liters volumetric or larger, desktop/tower orientation, mini-ITX and micro-ATX chassis with a chassis fan. The recommended fan type is an exhaust fan. For best thermal performance, it is recommended that the chassis fan provide reasonable airflow directly over the all the major components on the board. The pin fin heatsink is designed to have the best thermal performance when airflow direction is parallel to the heatsink fins. The processor on the board will generate the highest amount of heat, leading to high ambient temperature within the chassis. The chassis fan should be located near the board region in order to effectively regulate airflow (see Figure 17). A chassis fan located further away from the board region, i.e., at the optical disk drive or hard disk drive region, will be less effective in controlling the local ambient temperature. Regardless of where the chassis fan is located, the maximum local ambient temperature as defined by TA should be capped at 50 °C. Chassis inlet vents should also provide adequate openings for airflow to pass through. The recommended freearea-ratio of chassis vents should be equal to or greater than 0.53. By using the reference pin fin heatsink, most chassis with a chassis fan enabled should have local ambient temperature safely below the 50 °C limit. 55