Novel conductive adhesive technology for solar industry

Mosaic Solutions is developing an electrically conductive adhesive for solar cell manufacturing. The adhesive will be used to connect individual cells in series, replacing the current soldering technology. The goal is to create an adhesive that conducts electricity using our patented technology: Single-sized polymer particles coated with a thin layer of silver. If we succeed, this could revolutionise the production of solar panels. Our electrically conductive adhesive has two major advantages over soldering technology: The first being that the adhesive system is completely lead free. That is to say that the exemption from the lead ban, that the solar industry currently lives under, may be repealed. Secondly, an adhesive-process requires a lower temperature, and is thus a more gentle process. In this way solar cell breakage decreases. The research project is managed by Mosaic Solutions and runs in cooperation with a number of Scandinavian institutes and companies. The main focus is the development of particle technology, development of an adhesive that meets the requirements of the solar industry, and the production and testing of solar modules with electrically the conductive adhesive. Mosaic Solutions in collaboration with Conpart have produced large batches of silver plated particles, and confirmed that our processes are suitable for producing at a commercial scale. We are continuously working on improving the metal coating quality, and are cooperating with NTNU and our PhD candidate Sigurd Pettersen on characterisation of the mechanical and electrical properties of the particles. Mosaic Solutions works closely with a Lindberg & Lund to develop the adhesive. This work includes investigating various adhesive formulations, performing tests on adhesive mixing, and laboratory testing. In addition to developing a novel adhesive, Mosaic Solutions is also focused on how to replace the current soldering process in solar module production. We are working with several different application methods, and have made equipment for test module manufacturing. SweModule is a major supporter and together we have fabricated several test modules. The reliability of the test modules has been tested in temperature cycling and a damp heat tests. All panels passed, and we have gained new confidence in our concept. During 2016 we have focused a lot on commercial aspects, through disseminating research results, and investigation of newly developed particles. Further work after the project includes optimisation of the adhesive properties, with respect to electrical properties and reliability. Mosaic Solutions will also actively disseminate our research results both nationally and internationally.

The project "Novel Conductive Adhesives Technology Platform for Solar Industry" will provide enabling technology for the solar industry to help reduce the environmental impact of the solar module manufacturing. Due to the brittleness of the solar cells, t he present soldering process has been exempted from the lead ban that is put on the rest of the electronics industry. The only viable alternative is to use adhesive technology, which significantly reduces the bonding temperature and hence the mechanical s train on the cells. Such technology is also well suited for the next generation of solar modules, based on back-side contacted solar cells. The novel electrical conductive adhesive that is developed in this project reduces the amount of silver by an orde r of magnitude compared to present adhesives, which is also important from a cost perspective. The potential world market for conductive adhesives in solar applications is of the order of 300 MUSD, and the adhesive development will also have great interes t for electronics applications outside solar module manufacturing. In this project we have gathered a number of SMEs that cover the value chain from materials to final module assembly. We have joined forces with world leading institutes and universities t o solve the technological challenges in the project.