GE Industrial Solutions ESTW025A0F Series - Manual (Page 11)

Data Sheet
October 11, 2011
ESTW025A0F Series Eighth-Brick Power Modules
36–75Vdc Input; 3.3Vdc Output; 25A Output
LINEAGE POWER 11
Surface Mount Information (continued)
technology called “Column Pin” (CP) connectors.
Figure 19 shows the new CP connector before and
after reflow soldering onto the end-board assembly.
ESTW Board
Insulator
Solder Ball
End assembly PCB
Figure 21. 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.
Pb-free Reflow Profile
Power Systems will comply with J-STD-020 Rev. C
(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 22.
MSL Rating
The ESTW025A0F modules have a MSL rating of 2a.
Storage and Handling
The recommended storage environment and handling
procedures for moisture-sensitive surface mount
packages is detailed in J-STD-033 Rev. A (Handling,
Packing, Shipping and Use of Moisture/Reflow
Sensitive Surface Mount Devices). Moisture barrier
bags (MBB) with desiccant are required for MSL
ratings of 2 or greater. These sealed packages
should not be broken until time of use. Once the
original package is broken, the floor life of the product
at conditions of
 30°C and 60% relative humidity
varies according to the MSL rating (see J-STD-033A).
The shelf life for dry packed SMT packages will be a
minimum of 12 months from the bag seal date, when
stored at the following conditions: < 40° C, < 90%
relative humidity.
Post Solder Cleaning and Drying
Considerations
Post solder cleaning is usually the final circuit board
assembly process prior to electrical board testing. The
result of inadequate cleaning and drying can affect
both the reliability of a power module and the
testability of the finished circuit board assembly. For
guidance on appropriate soldering, cleaning and
drying procedures, refer to Lineage Power Board
Mounted Power Modules: Soldering and Cleaning
Application Note (AN04-001).
Figure 22. Recommended linear reflow profile
using Sn/Ag/Cu solder.
Through-Hole Lead-Free Soldering
Information
The RoHS-compliant through-hole products use the
SAC (Sn/Ag/Cu) Pb-free solder and RoHS-compliant
components. They are designed to be processed
through single or dual wave soldering machines. The
pins have a RoHS-compliant finish that is compatible
with both Pb and Pb-free wave soldering processes.
A maximum preheat rate of 3
C/s is suggested. The
wave preheat process should be such that the
temperature of the power module board is kept below
210
C. For Pb solder, the recommended pot
temperature is 260 C, while the Pb-free solder pot is
270 C 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 Lineage Power
representative for more details.
Per J-STD-020 Rev. C
0
50
100
150
200
250
300
Reflow Time (Seconds)
Re
fl
o
w
T
em
p
(
°C
)
He ating Zone
1°C/Second
Pe ak Temp 260°C
* Min. Time Above 235°C
15 Se conds
*Time Above 217°C
60 Seconds
Cooling
Zone