pip202-12m NXP Semiconductors, pip202-12m Datasheet - Page 15

• Manufacturer Part Number: pip202-12m
• Description: Dc To Dc Converter Powertrain
• Manufacturer: NXP Semiconductors

Philips Semiconductors
15. Soldering
9397 750 11943
Product data
Fig 18. Typical reflow soldering process flow.
POST REFLOW INSPECTION
15.1 Introduction to soldering MLF packages
REFLOW SOLDERING
(PREFERABLY X-RAY)
SOLDER PASTE
REWORK AND
COMPONENT
PRE REFLOW
INSPECTION
INSPECTION
POST PRINT
PLACEMENT
TOUCH UP
PRINTING
The MicroLeadFrame package (MLF) is a near Chip Scale Package (CSP) with a
copper leadframe. It is a leadless package, where electrical contact to the printed
circuit board is made through metal pads on the underside of the package. In addition
to the small pads around the periphery of the package, there are large pads on the
underside that provide low thermal resistance, low electrical resistance, low
inductance connections between the power components inside the MLF package and
the PCB. It is this feature of the MLF package that makes it ideally suited for VRM
applications.
Electrical connection between the package and the printed circuit board is made by
printing solder paste on the printed circuit board, placing the component and
reflowing the solder in a convection or infra-red oven. The solder reflow process is
shown in
ensure good solder joints, the peak temperature T
packages such as MLF, and the time above liquidus temperature should be less than
1.25 minutes. The maximum temperature can be increased for lead free solder. The
ramp rate during preheat should not exceed 3 K/s. Nitrogen purge is recommended
during reflow.
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Figure 18
Rev. 02 — 24 November 2003
and the typical temperature profile is shown in
Fig 19. Typical reflow soldering temperature profile.
Temp
( C)
300
200
100
T p
T r
T e
0
0
rate of rise of
temperature < 3 K/s
1 min max
p
should not exceed 220 C for thin
DC-to-DC converter powertrain
1
© Koninklijke Philips Electronics N.V. 2003. All rights reserved.
PIP202-12M-2
1.25 min max
2
Figure
time (minutes)
19. To
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3
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