Data Sheet
GE
KSTW015A0F Barracuda™ Series; DC-DC Converter Power Modules
36-75Vdc Input; 3.3Vdc, 15A Output
Reflow Soldering Information
Layout Considerations (continued)
RoHS-compliant finish that is compatible with both Pb and Pb-
free wave soldering processes. A maximum preheat rate of
3C/s is suggested. The wave preheat process should be such
that the temperature of the power module board is kept below
210C. For Pb solder, the recommended pot temperature is
260C, while the Pb-free solder pot is 270C max. Not all RoHS-
compliant through-hole products can be processed with paste-
through-hole Pb or Pb-free reflow process. If additional
information is needed, please consult with your GE
These power modules are large mass, low thermal
resistance devices and typically heat up slower than other
SMT components. It is recommended that the customer
review data sheets in order to customize the solder reflow
profile for each application board assembly.
The following instructions must be observed when SMT
soldering these units. Failure to observe these instructions
may result in the failure of or cause damage to the modules,
and can adversely affect long-term reliability.
representative for more details.
There are several types of SMT reflow technologies currently
used in the industry. These surface mount power modules
can be reliably soldered using natural forced convection, IR
(radiant infrared), or a combination of convection/IR. The
recommended linear reflow profile using Sn/Pb solder is
shown in Figure 19 and 20. For reliable soldering the solder
reflow profile should be established by accurately measuring
the module’s pin connector temperatures.
Surface Mount Information
Pick and Place
The KSTW-SR series of DC-to-DC power converters use an
open-frame construction and are designed for surface mount
assembly within a fully automated manufacturing process.
The KSTW-SR series modules are designed to use the main
magnetic component surface to allow for pick and place.
300
Peak Temp 235oC
250
Cooling
zo ne
Heat zone
max4oCs-1
200
150
10 0
50
1- 4 oCs-1
Soak zone
30-240s
T
lim above
205oC
Preheat zone
max4oCs-1
0
REFLOW TIME (S)
Figure 19. Recommended Reflow Profile for Sn/Pb solder.
Note: All dimensions in mm [in].
240
235
230
225
220
215
210
205
200
Figure 18. Pick and Place Location.
Z Plane Height
The ‘Z’ plane height of the pick and place location is 7.50mm
nominal with an RSS tolerance of +/-0.25 mm.
Nozzle Recommendations
The module weight has been kept to a minimum by using open
frame construction. Even so, they have a relatively large mass
when compared with conventional SMT components.
Variables such as nozzle size, tip style, vacuum pressure and
placement speed should be considered to optimize this
process.
0
10
20
30
40
50
60
TIME LIMIT (S)
Figure 20. Time Limit, Tlim, Curve Above 205oC Reflow .
Lead Free Soldering
The minimum recommended nozzle diameter for reliable
operation is 5mm. The maximum nozzle outer diameter, which
will safely fit within the allowable component spacing, is
6.5mm.
The –Z version SMT modules of the KSTW015A0F series are
lead-free (Pb-free) and RoHS compliant and are compatible in a
Pb-free soldering process. Failure to observe the instructions
below may result in the failure of or cause damage to the
modules and can adversely affect long-term reliability.
Oblong or oval nozzles up to 11 x 6 mm may also be used
within the space available.
For further information please contact your local GE Technical
Sales Representative.
April 1, 2013
©2012 General Electric Company. All rights reserved.
Page 10
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