With a growing global focus on green energy, companies are racing to develop higher efficiency and lower cost solar cells for various applications. OEMs recognize the need for mechanical testing to evaluate mechanical performance of thin films and substrates used in the manufacturing of photovoltaic (PV) cells, also known as solar cells. The International Electrotechnical Commission (IEC), a world leading governing body, has published standards, such as IEC 61646, Thin Film Terrestrial Photovoltaic Modules – Design Qualification and Type Approval, and IEC 61215, Crystalline Silicone Terrestrial Photovoltaic Modules – Design Qualification and Type Approval, that focus on mechanical testing of PV modules that simulate external conditions, such as withstanding a wind pressure of 130 km/hour.
A 90 degree peel adhesion test on various layers of thin films, also known as stacks, is recommended for the described challenges. The test confirms the quality of the adhesion between layers. Peel strength can be computed, which estimates the adhesion strength for a reliable, long-term electrical interconnection between layers. Instron’s 5900 and 3300 series systems are suitable for 90 degree peel testing applications. Bluehill® Universal software can be used to set up test methods and collect results post testing. The 90 degree peel fixture is designed with zero friction so that all force measurements are a direct outcome of the film and adhesive under test. Furthermore, Instron offers a variable angle peel fixture for testing PV modules at angles other than 90 degrees, such as 45 degree or 30 degree peel testing.