RMPA1959 Datasheet, PDF (9/11 Pages) Fairchild Semiconductor – PCS 3.4V CDMA & CDMA2000-1X PowerEdge Power Amplifier Module

Application Information
CAUTION: THIS IS AN ESD SENSITIVE DEVICE
Precautions to Avoid Permanent Device Damage:
• Cleanliness: Observe proper handling procedures to
ensure clean devices and PCBs. Devices should remain
in their original packaging until component placement to
ensure no contamination or damage to RF, DC & ground
contact areas.
• Device Cleaning: Standard board cleaning techniques
should not present device problems provided that the
boards are properly dried to remove solvents or water
residues.
• Static Sensitivity: Follow ESD precautions to protect
against ESD damage:
– A properly grounded static-dissipative surface on
which to place devices.
– Static-dissipative floor or mat.
– A properly grounded conductive wrist strap for each
person to wear while handling devices.
• General Handling: Handle the package on the top with a
vacuum collet or along the edges with a sharp pair of
bent tweezers. Avoiding damaging the RF, DC, & ground
contacts on the package bottom. Do not apply excessive
pressure to the top of the lid.
• Device Storage: Devices are supplied in heat-sealed,
moisture-barrier bags. In this condition, devices are
protected and require no special storage conditions.
Once the sealed bag has been opened, devices should
be stored in a dry nitrogen environment.
Device Usage:
Fairchild recommends the following procedures prior to
assembly.
• Dry-bake devices at 125°C for 24 hours minimum. Note:
The shipping reels cannot withstand 125°C baking
temperature.
• Assemble the dry-baked devices within 7 days of
removal from the oven.
• During the 7-day period, the devices must be stored in an
environment of less than 60% relative humidity and a
maximum temperature of 30°C
Solder Materials & Temperature Profile: Reflow
soldering is the preferred method of SMT attachment. Hand
soldering is not recommended.
• Reflow Profile
– Ramp-up: During this stage the solvents are
evaporated from the solder paste. Care should be
taken to prevent rapid oxidation (or paste slump) and
solder bursts caused by violent solvent out-gassing. A
typical heating rate is 1- 2°C/sec.
– Pre-heat/soak: The soak temperature stage serves
two purposes; the flux is activated and the board and
devices achieve a uniform temperature. The
recommended soak condition is: 120-150 seconds at
150°C.
– Reflow Zone: If the temperature is too high, then
devices may be damaged by mechanical stress due to
thermal mismatch or there may be problems due to
excessive solder oxidation. Excessive time at
temperature can enhance the formation of inter-
metallic compounds at the lead/board interface and
may lead to early mechanical failure of the joint.
Reflow must occur prior to the flux being completely
driven off. The duration of peak reflow temperature
should not exceed 10 seconds. Maximum soldering
temperatures should be in the range 215-220°C, with
a maximum limit of 225°C.
– Cooling Zone: Steep thermal gradients may give rise
to excessive thermal shock. However, rapid cooling
promotes a finer grain structure and a more crack-
resistant solder joint. The illustration below indicates
the recommended soldering profile.
Solder Joint Characteristics:
Proper operation of this device depends on a reliable void-
free attachment of the heatsink to the PWB. The solder joint
should be 95% void-free and be a consistent thickness.
Rework Considerations:
Rework of a device attached to a board is limited to reflow
of the solder with a heat gun. The device should not be
subjected to more than 225°C and reflow solder in the
molten state for more than 5 seconds. No more than 2
rework operations should be performed.
• If the 7-day period or the environmental conditions have
been exceeded, then the dry-bake procedure must be
repeated.
©2004 Fairchild Semiconductor Corporation
RMPA1959 Rev. D