20a digital microdlynx, Non-isolated dc-dc power modules, Data sheet – GE Industrial Solutions 20A Digital MicroDLynx User Manual
Page 39: Surface mount information

GE
Data Sheet
20A Digital MicroDLynx
TM
: Non-Isolated DC-DC Power Modules
3Vdc –14.4Vdc input; 0.45Vdc to 5.5Vdc output; 20A Output Current
April 24, 2013
©2012 General Electric Company. All rights reserved.
Page 39
Surface Mount Information
Pick and Place
The 20A Digital MicroDLynx
TM
modules use an open frame
construction and are designed for a fully automated
assembly process. The modules are fitted with a label
designed to provide a large surface area for pick and place
operations. The label meets all the requirements for surface
mount processing, as well as safety standards, and is able
to withstand reflow temperatures of up to 300
o
C. The label
also carries product information such as product code,
serial number and the location of manufacture.
Nozzle Recommendations
The module weight has been kept to a minimum by using
open frame construction. Variables such as nozzle size, tip
style, vacuum pressure and placement speed should be
considered to optimize this process. The minimum
recommended inside nozzle diameter for reliable operation
is 3mm. The maximum nozzle outer diameter, which will
safely fit within the allowable component spacing, is 7 mm.
Bottom Side / First Side Assembly
This module is not recommended for assembly on the
bottom side of a customer board. If such an assembly is
attempted, components may fall off the module during the
second reflow process.
Lead Free Soldering
The modules are lead-free (Pb-free) and RoHS compliant
and fully 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.
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). For questions regarding Land grid array(LGA)
soldering, solder volume; please contact Lineage Power for
special manufacturing process instructions. The
recommended linear reflow profile using Sn/Ag/Cu solder is
shown in Fig. 50.
Soldering outside of the recommended
profile requires testing to verify results and performance.
MSL Rating
The 20A Digital MicroDLynx
TM
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.
Figure 50. Recommended linear reflow profile using
Sn/Ag/Cu solder.
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 Board Mounted Power Modules: Soldering and Cleaning
Application Note (AN04-001).
Per J-STD-020 Rev. C
0
50
100
150
200
250
300
Reflow Time (Seconds)
R
ef
lo
w
T
em
p
(
°C
)
Heating Zone
1°C/Second
Peak Temp 260°C
* Min. Time Above 235°C
15 Seconds
*Time Above 217°C
60 Seconds
Cooling
Zone