47062 SR5650 Databook 2.00
© 2010 Advanced Micro Devices, Inc.
5-6
Proprietary
Package Information
•
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.
5.3.2
Board Solder Reflow Process Recommendations
5.3.2.1 Stencil Opening Size for Solderball Pads on PCB
Warpage of the PCB and the package may cause solderjoint quality issues at the surface mount. Therefore, it is
recommended that the stencil opening sizes be adjusted to compensate for the warpage. The recommendation is for the
stencil aperture of the solderballs to be kept at the same size as the pads.
5.3.2.2 Reflow Profile
A reference reflow profile is given below. Please note the following when using RoHS/lead-free solder (SAC105/305/405
Tin-Silver-Cu):
•
The final reflow temperature profile will depend on the type of solder paste and chemistry of flux used in the SMT
process. Modifications to the reference reflow profile may be required in order to accommodate the requirements of
the other components in the application.
•
An oven with 10 heating zones or above is recommended.
•
To ensure that the reflow profile meets the target specification on both sides of the board, a different profile and oven
recipe for the first and second reflow may be required.
•
Mechanical stiffening can be used to minimize board warpage during reflow.
•
It is suggested to decrease temperature cooling rate to minimize board warpage.
•
This reflow profile applies only to RoHS/lead-free (high temperature) soldering process and it should not be used for
Eutectic solder packages. Damage may result if this condition is violated.
•
Maximum 3 reflows are allowed on the same part.
Table 5-7 Recommended Board Solder Reflow Profile - RoHS/Lead-Free Solder
Profiling Stage
Temperature
Process Range
Overall Preheat
Room temp to 220
C
2 mins to 4 mins
Soaking Time
130
C to 170
C
Typical 60 – 80 seconds
Liquidus 220
C
Typical 60 – 80 seconds
Ramp Rate
Ramp up and Cooling
<2
C / second
Peak Max.
245
C 235
C +/-5
C
Temperature at peak
within 5
C
240
C to 245
C
10 – 30 seconds