What is lpi screening in pcb?

LPI screening in PCB (Printed Circuit Board) refers to the process of applying Liquid Photoimageable (LPI) solder mask to the surface of the PCB. This technique involves using a photosensitive liquid material that is exposed to UV light through a patterned mask, allowing selective areas to be coated while others remain exposed for soldering components. LPI screening enhances the durability and reliability of the PCB by providing protection against environmental factors and reducing the risk of solder bridging during assembly. This method is favored for its precision and ability to create fine details in the mask application.