SCHMID consistently promotes the industrial use of the SCHOTT Solar licensed PERC processes, which is backed up by the continuous increase in efficiency from the record level of 20.2% in summer 2012 to the current 20.74%.
A further process building block after the successful backside passivation using the APCVD is the opening of the passivation layer at the highest speed by SCHMID's Laser Treatment Machine for PERC (LTM-PERC).
SCHMID has designed the LTM-PERC with particular strong focus on cost effectiveness and yield. Dr. Jens Tobai, the product manager for laser technology, describes the principles of the development phase:
"We know the cost structure of the manufacturers. We have, therefore, adapted the machine to consistently reach higher throughputs and accurate automation. With our measures we have been able to increase the throughput compared to standard systems by at least 30% and reduce the breakage rate to zero. We are also familiar with the structure of the newest high efficiency cells in detail, as we develop them ourselves in our own research centers. Through the intelligent use of our machine we are able to increase the throughput with particular cells by 100%."
The basic components of the machine are the picosecond laser from Lumera and a high precision automation belt. Neither are ever standing still which accounts for the high duty cycle of the laser and the high throughput. Supplying the machine with a customer specific laser is possible without any difficulty. A precise camera system takes care of determining the exact position of a cell. The continuous movement of the cells takes place smoothly and using a gripper system is completely avoided. Through these components error-free processing as well as error-free transport is guaranteed and high yields are achieved.
Maintenance work hardly reduces the high uptime of the machine, as robust components are exclusively used.
Changes to the process parameters are flexibly configurable. So the necessary settings are carried out by the user through the user friendly graphical interface. All the process residues of the laser work are effectively removed through an air knife and an exhaust system.
SCHMID's Laser Treatment for PERC is available from Q1/2013.
Source: SCHMID Group | Gebr. SCHMID GmbH