GE Industrial Solutions SW-SC001-003 Series - Manual (Page 17)

GE Data Sheet
SW/SC001/003 Series DC-DC Power Module
18-36Vdc & 36-75Vdc Input; 3.3-15Vdc Output; 1-3.5A Output Current
October 14, 2013 ©2013 General Electric Company. All rights reserved. Page 17
Reflow Soldering Information
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.
Surface Mount Information
(continued)
The surface mountable modules in the SW/SC family use our
SMT technology called “Column Pin” (CP) connectors. Figure
53 shows the CP connector before and after reflow soldering
onto the end-board assembly.
Power Module Board
Insulator
Solder Ball
End assembly PCB
Figure 53. Column Pin Connector Before and After Reflow
Soldering.
The CP is constructed from a solid copper pin with an integral
solder ball attached, which is composed of tin/lead (Sn
63
/Pb
37
)
solder for non-Z codes, or Sn/Ag
3.8
/Cu
0.7
(SAC) solder for –Z
codes. The CP connector design is able to compensate for
large amounts of co-planarity and still ensure a reliable SMT
solder joint. Typically, the eutectic solder melts at 183
o C (Sn/Pb
solder) or 217-218 o C (SAC solder), wets the land, and
subsequently wicks the device connection. Sufficient time
must be allowed to fuse the plating on the connection to
ensure a reliable solder joint.
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 54 and 55. For reliable soldering the solder reflow
profile should be established by accurately measuring
the
modules CP connector temperatures.
Lead Free Soldering
M
AX
T
EM
P
SO
LDE
R
(
 C)
TIME LIMIT (S)
Figure 54. Recommended Reflow Profile for Sn/Pb solder.
The –Z version SMT modules of the SW/SC 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
RE
FLO
W
T
EM
P
( 
C)
REFLOW TIME (S)
Figure 55. Time Limit, T
lim
, Curve Above 205 o C Reflow .
Pb-free Reflow Profile
Power Systems will comply with J-STD-020 Rev. D
(Moisture/Reflow Sensitivity Classification for Nonhermetic
Solid State Surface Mount Devices) for both Pb-free solder
profiles and MSL classification procedures. This standard
provides a recommended forced-air-convection reflow profile
based on the volume and thickness of the package (table 4-2).
The suggested Pb-free solder paste is Sn/Ag/Cu (SAC). The
recommended linear reflow profile using Sn/Ag/Cu solder is
shown in Figure. 56.