Data Sheet
EHW015A0A Series Eighth-Brick Power Modules
36–75Vdc Input; 5.0Vdc Output; 15A Output Current
June 29, 2009
Thermal Considerations (continued)
Surface Mount Information
16
Pick and Place
14
12
The EHW015A0A-S 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 300oC. The label also carries product
information such as product code, serial number and
the location of manufacture.
10
2.0 m/s
(400 LFM)
8
1.0 m/s
(200 LFM)
6
0.5 m/s
(100 LFM)
4
2
0
NC
20
30
40
50
60
70
80
90
AMBIENT TEMEPERATURE, TA (oC)
Figure 19. Output Current Derating for the Module
with Heatplate and 1.0 in. heat sink; Airflow in the
Transverse Direction from Vout(+) to Vout(-); Vin
=48V.
Please refer to the Application Note “Thermal
Characterization Process For Open-Frame Board-
Mounted Power Modules” for a detailed discussion of
thermal aspects including maximum device
temperatures.
Figure 23. Pick and Place Location.
Nozzle Recommendations
Heat Transfer via Conduction
The module can also be used in a sealed
environment with cooling via conduction from the
module’s top surface through a gap pad material to a
cold wall, as shown in Figure 20. The output current
derating versus cold wall temperature, when using a
gap pad such as Bergquist GP2500S20, is shown in
Figure 21.
The module weight has been kept to a minimum by
using open frame construction. Even so, these
modules have a relatively large mass when compared
to conventional SMT components. Variables such as
nozzle size, tip style, vacuum pressure and placement
speed should be considered to optimize this process.
The minimum recommended nozzle diameter for
reliable operation is 6mm. The maximum nozzle outer
diameter, which will safely fit within the allowable
component spacing, is 9 mm.
Oblong or oval nozzles up to 11 x 9 mm may also be
used within the space available.
The surface mountable modules in the EHW family use
our newest SMT technology called “Column Pin” (CP)
connectors. Figure 24 shows the new CP connector
before and after reflow soldering onto the end-board
assembly.
Figure 20. Cold Wall Mounting
16
14
12
10
8
EHW Board
6
Insulator
4
Solder Ball
2
20
30
40
50
60
70
80
90
End assembly PCB
COLDPLATE TEMEPERATURE, TC (oC)
Figure 24. Column Pin Connector Before and After
Reflow Soldering .
Figure 21. Derated Output Current versus Cold Wall
Temperature with local ambient temperature
around module at 85C; Vin=48V.
LINEAGE POWER
10
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
