Product Briefing Outline: MANZ print station powered by Optomec Aerosol Jet
Manz offers a new print station for contact-less printing of crystalline solar cells using OPTOMEC Aerosol Jet technology and will be the exclusive sales and marketing partner for the Optomec solar applications. Optomec has developed an advanced contact free metallization process for crystalline solar cells. Manz will integrate the Optomec technology into its back end line platform.
Problem: To manufacture crystalline solar cells, electrical contacts must be created on the front and back side of the solar cell. The three metal layers (one on the front and two on the rear side) are currently printed using a screen-printing process. Metal particles dissolved in a solvent are transferred to the solar cell through a textured screen. The wet paste then must be dried in an oven after each printing step. However the screen-printing process is reaching its limits as the industry pushes for higher efficiency solar cells and thinner wafers. For example, losses due to shadowing can be reduced by printing conductive lines that are narrower than what is possible with screen printers. Further, as thinner wafers are introduced into production lines, waste due to wafer breakage becomes more significant. Depending on the wafer manufacturing process, screen printing can generate high breakage rates that results in lower margins. Therefore it is desirable to utilize a printing solution that simultaneously can reduce line widths and print in a non-contact fashion.
Solution: The MANZ/ Optomec solution utilizes a proprietary Aerosol Jet technology capable of depositing inks, pastes, or other liquid materials on a variety of surfaces with printed features below 40 microns. Aerosol Jet technology is a non-contact direct write process that is able to print much finer lines than is currently possible with traditional screen-printing. The narrower, high integrity collector lines have higher conductivity and a lower shadowing effect, thereby increasing photovoltaic cell efficiency. In addition, because the process is non-contact, Aerosol Jet technology can print on thinner wafers and with less breakage than screen-printing techniques. The Optomec solution, together with an additional electroplating process, shows efficiency improvements of solar cells of 0.5 -1% or more in absolute figures as documented by Fraunhofer ISE.
Application: Contact free printing of high efficient crystalline solar cells.
Platform: Integrated Optomec Aerosol Jet into MANZ IPC module.
Availability: Starting September 2008 for selected customers.