This Standard was technically approved by the global
Photovoltaic Technical Committee. This edition was approved for publication by
the global Audits and Reviews Subcommittee on August 30, 2012. Available at
www.semiviews.org and www.semi.org in September 2012.
For c-Si technology, one of the problems is to identify
and eliminate the sources of mechanical defects such as thermo-elastic stress
and cracks leading to the loss of wafer integrity and ultimate breakage of
as-grown and processed Si cells. A significant challenge in using thinner
crystalline silicon wafers for solar cell manufacture is the reduced yield due
to increased cell breakage. Cell breakage mostly depends on the stresses induced
in the processing, handling and transportation, and also depends on the presence
of defects such as micro-cracks. Shipping damage is always one of the top
problems of the PV failures in the field.
This Standard presents a test method for mechanical
vibration of c-Si PV cells in transportation environment, which might be carried
by truck, train, aircraft and shipboard, etc. This Standard aims to provide a
common test method to evaluate the micro-cracks or defects on the PV cells due
to stress during transportation. The cell makers and buyers, or any other party
interested, can thus have a common testing standard to refer to when
The test result also can evaluate cell package
performance during transportation.
Basic Test System Requirements — This Standard
states the basic vibration test system requirements.
This Test Method covers the random vibration test of
filled transportation unit, will be used to assess the performance of package
design for mono/multicrystalline cells during shipping by different
Testing Procedure — The general testing procedures are
provided with a flowchart, including the vibration test, pre-test and post-test
examination of the PV cells performance, according to current IEC standards.
These specifications for the vibration, including the frequency range and power
spectral density, etc., corresponding to particular means of transportation are
chosen by the user according to existing standards (e.g., ASTM, MIL-STD).
Sampling Method — Usually multiple PV cells are
stacked as a block; multiple blocks are stacked as a box and shipped boxes
together in a test specimen. It is unnecessary, time-consuming and
cost-intensive to carry out full performance tests on all blocks in the same
test specimen. Therefore, select suitable test blocks of cells that undergo the
pre-test and post-test examinations shall be helpful.
Sample Report and Data Formats — Results and
relevant information are stated in the final test report to the customer, and in
recommended report and data formats in the
SEMI PV23 —
Test Method for Mechanical Vibration of Crystalline Silicon Photovoltaic (PV)
Modules in Shipping Environment