Intel 200 User Manual

16  

 

Thermal and Mechanical Design Guidelines 

The micro-FCBGA package may have capacitors placed in the area surrounding the 

processor die.  The die-side capacitors, which are only slightly shorter than the die 

height, are electrically conductive and contact with electrically conductive materials 

should be avoided.  The use of an insulating material between the capacitors and any 

thermal and mechanical solution should be considered to prevent capacitors shorting.  

A thermal and mechanical solution design must not intrude into the required keep-out 

zones as specified in the datasheet.   

There are no features on the 479-pins micro-FCBGA package for direct heatsink 

attachment: a mechanism must be designed to attach the heatsink directly to the 

motherboard.  In addition to holding the heatsink in place on top of the processor die, 

this mechanism plays a significant role in the robustness of the system in which it is 

implemented, in particular: 

•  Ensuring thermal performance of the thermal interface material (TIM) applied 

between the processor die and the heatsink.  TIMs based on phase change 

materials are very sensitive to applied pressure: the higher the pressure, the 

better the initial performance.  Designs should incorporate a possible decrease in 

applied pressure over time due to potential structural relaxation in retention 

components (creep effect causing clip to lose its preload and causing anchor pull-

out).  It is not recommended to use TIMs such as thermal greases onto small bare 

die package, due to the TIM “pump-out” concern after heatsink is assembled.  

•  Ensuring system electrical, thermal, and structural integrity under shock and 

vibration events.  The mechanical requirements of the heatsink attach mechanism 

depend on the mass of the heatsink and the level of shock and vibration that the 

system must support.  The overall structural design of the motherboard and the 

system should be considered in designing the heatsink attach mechanism.  The 

design should provide a means for protecting the solder joints.     

The attach mechanism for the heatsink developed to support the processor creates a 

nominal static compressive preload on the package of 9.9 lbf ± 1.2 lbf throughout the 

life of the product for designs compliant with the Intel reference design assumptions: 

•  Using TIM Honeywell PCM45F (pad version). 

•  55.88 mm (2.2”) x 54.88 mm (2.16”) attach pattern. Refer to Figure 21 for 

heatsink keep-out zone.  

•  And no board stiffening device (backing plate, chassis attach, etc.).  

The minimum load is required to thermal performance while protecting solder joint 

against fatigue failure in temperature cycling.  

Notes the load range above is required to ensure a minimum load of 8.7lbf at end-of-

life.  The tolerance and nominal load is based on reference design and will slightly 

differ on alternate thermal solution provided by third party. 

It is important to take into account potential load degradation from creep over time 

when designing the clip or fastener to the required minimum load. This means that,