VENDORVIEW
Drilling Crystalline Cells with Disc Lasers necessary soldering lines
Due to its exceptional material processing which are required for the
properties, especially the disc laser concept is interconnection within the
gaining serious acceptance in solar cell solar module, are
production. Compared to a rod, a disc laser offers positioned on the rear side
much higher average power with best beam of the solar cell. For this
quality. Therefore ROFIN’s q-switched disc laser purpose, 25-100 holes
StarDisc increases throughput rates by the factor with a diameter of 200-500
three to five when drilling via holes in solar cells, µm are drilled in a grid
and thus opens up completely new laser pattern on one solar cell
applications. The q-switched beam source and then filled with conductive
provides both high power in TEM00 fundamental material. The PowerLine SL
mode and ideal pulse widths for these series was specifically
applications. The fundamental process of drilling If, however, the entire contacting of the emitter designed for scribing
applications on solar cells is direct laser layer is located on the rear, approx. 15,000 holes of photovoltaic and
vaporization and melt ejection by laser pulses with with a diameter of 60-70 µm are drilled (emitter other electric thin-films
a puls duration of 500 – 1,000 nsec. The wrap through method - EWT). For both techniques,
combination of high pulse peak power together the disc laser combines unmatched throughput
with material adjusted pulse duration provides for rates with precision and excellent surface quality.
extremely short processing times per solar cell in
the range of only few seconds. These are optimal In the near future photovoltaic energy production
preconditions for inline integration of rear side will be able to compete with conventional energy
contacting processes into the production line. sources without subsidization. Without the
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constant advancement in laser material processing
With the MWT method (metal wrap through), the this success would almost be inconceivable.
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Issue V 2009
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