41978 AMD RS690M Databook 3.06
© 2008 Advanced Micro Devices, Inc.
5-8
Proprietary
Package Information
Figure 5-4 RS690M Ball Arrangement
5.3.2
Pressure Specification
To avoid damages to the ASIC (die or solder ball joint cracks) caused by improper mechanical assembly of the cooling
device, follow the recommendations below:
•
It is recommended that the maximum pressure which is evenly applied across the contact area between the
thermal management device and the die does not exceed 40 PSI. Note that a contact pressure of 30-40 PSI is
adequate to secure the thermal management device and achieve the lowest thermal contact resistance with a
temperature drop across the thermal interface material of no more than 3°C. Also, the surface flatness of the
metal spreader should be 0.001 inch/1 inch.
•
Pre-test the assembly fixture with a strain gauge to make sure that the flexing of the final assembled board and
the pressure applying around the ASIC package will not exceed 600 micron strain under any circumstances.
•
Ensure that any distortion (bow or twist) of the board after SMT and cooling device assembly is within industry
guidelines (IPC/EIA J-STD-001). For measurement method, refer to the industry approved technique described
in the manual IPC-TM-650, section 2.4.22.
