8
www.fairchildsemi.com
FMPA2300 Rev. A
F
Applications 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 and 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, and 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.
Assemble the devices within 7 days of removal from the dry
pack.
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
If the 7-day period or the environmental conditions have been
exceeded, then the dry-bake procedure, at 125°C for 24 hours
minimum, must be performed.
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 maximum heating rate is 3°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: 60-180 seconds at 150-200°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 20 seconds.
Soldering temperatures should be in the range 255–260°C,
with a maximum limit of 260°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 heat sink 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 be subjected to no
more than 15°C above the solder melting temperature for no
more than 5 seconds. No more than 2 rework operations should
be performed.
Recommended Solder Reflow Profile
150
Ramp-Up Rate
3
°
C/sec max
25
T
°
C
Time 25
°
C/sec to peak temp
6 minutes max
Ramp-Down Rate
6
°
C/sec max
Preheat, 150 to 200
°
C
60 - 180 sec
200
217
Time above
liquidus temp
60 - 150 sec
100
260
Peak temp
260 +0/-5
°
C
10 - 20 sec
Time (Sec)
Ramp-Up Rate
3
°
C/sec max
50