GE Industrial Solutions 3A Analog PicoDLynx - Manual (Page 22)

GE
Preliminary Data Sheet
3A Analog PicoDLynx TM : Non-Isolated DC-DC Power Modules
3Vdc –14.4Vdc input; 0.6Vdc to 5.5Vdc output; 3A Output Current
December 7, 2012 ©2012 General Electric Company. All rights reserved. Page 22
Surface Mount Information
Pick and Place
The 12VAnalog PicoDLynx TM 3A 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 12VAnalog PicoDLynx TM 3A modules are lead-free (Pb-
free) and RoHS compliant and
are both forward and backward compatible in a Pb-
free
and a SnPb 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 5-2). The suggested Pb-free solder paste is Sn/Ag/Cu
(SAC). For questions regarding LGA, solder volume; please
contact GE for special manufacturing process instructions.
The recommended linear reflow profile using Sn/Ag/Cu
solder is shown in Fig. 48.
Soldering outside of the
recommended profile requires testing to verify results and
performance.
It is recommended that the pad layout include a test pad
where the output pin is in the ground plane. The
thermocouple should be attached to this test pad since this
will be the coolest solder joints. The temperature of this
point should be:
Maximum peak temperature is 260 C.
Minimum temperature is 235 C.
Dwell time above 217 C: 60 seconds minimum Dwell time
above 235 C: 5 to 15 second
MSL Rating
The 12VAnalog PicoDLynx TM 3A 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. B (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 48. 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).