The latest issue of Circuitree Magazine came to me the other day and it was clear that this issue had a solar assembly focus. The cover story “Photovoltaics, The Great Illumination” was admittedly a very generic title, I didn’t expect much more than some ‘bright future of solar’ marketing outlook – I’m so glad I kept reading.
The article (written by Don Cullen of MacDermid) was a well-written introduction to Nickel, Copper, Silver plated conductors as a replacement for the traditional Ag/glass frit material and process. This metallization offers various benefits as outlined in the article, but why am I so excited? The same reason you should be, this should be an easier and more reliable surface for soldering tabbing ribbon. Instead of the partial Ag surface, the plated conductors offer a 100% solderable surface.
This is an image of a nickel seed layer on monocrystalline silicon 'pyramids'. The first step in building this metallization.
Don had this to say about plated metallizations: "The standard method for conductor formation on silicon solar cells is too wasteful, too expensive, and too restrictive for really widespread deployment of solar cells on the world's rooftops. We need to make the same leaps in technology that the circuit board and semiconductor industry have made time and time again. We need the elegant design of plated metal conductors. The superior contact, improved adhesion, predictable soldering, and excellent conductivity of a nickel, copper, silver conductor will allow the strong, consistent, cost-effective cells that will change our planet's thinking about energy."