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2020-06-04 | Document No.: AN149
Figure 12: Arrangement of the carrier and step-down stencil
These are slotted and matched to the step-down stencil and the design of the
corresponding carrier (see Figure 13).
(Further information on this procedure can be requested from company Christian
Koenen GmbH, for example.)
Figure 13: Example of a special squeegee blade
A correct solder paste print is the basis for the assembly with the corresponding
SMT connector. This process can be performed manually, but it is
recommended that automated assembly with a pick-and-place machine is used
for mass production.
For the OSRAM OSTAR
®
Projection Power, a standard reflow soldering process
with forced convection can be applied. Since the soldering atmosphere and in
particular air reflow can cause degradation of optical parameters it is advisable
to use an N
2
atmosphere (<500 ppm O
2
). Figure 14 shows the temperature
profile for lead-free soldering with the recommended peak temperature of
245 °C. Due to the high thermal mass of the Cu based substrate it is not
recommended to perform manual soldering with a soldering iron or heating guns.
Slit squeegee blade
Step-down stencil
