VTT Technical Research Centre of Finland and the Finnish illuminated sign company Neonelektro Oy have created a new type of flexible LED panel that uses roll-to-roll manufacturing technology to combine injection molding with printed electronics. The development was for the OptIntegral project, a European project that was completed at the end of January. The researchers anticipate the development will be used for advertising and marketing.
“Flexible, light weight, and of an easily customizable size, the LED advertising panel enables the creation of a dynamic look for large area applications, or those that require a 3D shape, such as vehicles,” said project manager Eveliina Juntunen of VTT.
Researchers Used Over-molding as Part of OPTintegral Project
They immersed a flexible electronics substrate in an over-molded polymer that protects the components and enables the integration of additional features, such as optical and mechanical structures during a single processing step.
The researchers applied the technology to the production of large area LED displays during the project. They used over-molding to add optical structures to the display elements and improve the visual appearance of the product. In addition to improving the appearance, VTT’s measurements show that over-molding lowers the temperature of the LEDs by around 20%, which translates to significantly improved reliability and efficiency of the LEDs. Together with the flexible substrate, the integrated optical and mechanical elements, and the over-molding combine to makes the displays energy-efficient, lightweight, and flexible.
VTT Technical Research Centre of Finland (VTT) used a roll-to-roll process that they used to make the flexible LED substrates. Then, they refined the process to make it more productive. Neonelektro Oy developed an over-molded RGB display element fabricated using the roll-to-roll technique.