Ferro Launches Eight Metallization Materials

Ferro Corporation´s Electronic Material Systems business, a leading supplier of materials for fabricating photovoltaic silicon solar cells for more than 20 years, broadened its product line with eight new products that improve electrical output, efficiency, and manufacturability, enabling solar energy to become a more cost-competitive energy generation alternative. The products were introduced at the 22nd European Photovoltaic Solar Energy Conference and Exhibition held in Milan, Italy, September 3-7, 2007.

Front Silver Contacts

The four products in this family yield greater power output, they fire through silicon nitride anti-reflective coatings, and also provide a broad processing window. They are compatible with all Ferro rear silver pastes as well as lead-free and low-bow aluminum pastes.

In addition, two of the products offer the advantages of Ferro´s patented Hot Melt ink technology. This specially designed silver conductor system eliminates the drying process of conventional pastes, resulting in higher throughput rates, increased productivity, improved yields, and reduction of volatile organic compounds (VOCs). Solid at room temperature, Hot Melt pastes are resistively heated above their melting points to screen print similarly to conventional thick film pastes. Unlike conventional pastes, they instantly re-solidify when transferred to the solar cell surface and are ready for the next printing sequence. This unique property also enables printing finer grid lines, contributing to a higher cell efficiency than can be achieved with conventional screen printing materials.

Aluminum Compositions

Ferro´s new lead- and cadmium-free aluminum/boron conductor is designed for the back surface of thin silicon wafers. It exhibits less than 1 millimeter camber on 150 x 150 millimeter wafers at 160 microns thickness, enabling solar cell manufacturers to reduce silicon usage and costs. It also yields a smooth surface and high electrical efficiency.

A new lead-free aluminum conductor for the back surface of silicon wafers is specially formulated to facilitate firing through silicon nitride anti-reflective coatings. It exhibits less than 1 millimeter camber on 150 x 150 millimeter wafers at 200 microns thickness, and provides a smooth surface and high electrical efficiency.

High Adhesion Rear Silvers

These two products are cadmium-free silver conductor pastes designed to provide high adhesion with lead-free and leaded tabbing ribbon as well as improved electrical performance. One is formulated as a conventional screen printing ink, and the other offers the additional manufacturing benefits of Ferro´s Hot Melt ink technology. Both are compatible with all Ferro leaded and lead-free aluminum inks, and have excellent solderability when used with leaded and lead-free solders.

All eight new products are RoHS-compliant.