Development of a Novel Negative-Tone Dry Film Resist with PVA Layer for Wiring with 1.5/1.5 µm Line/Space

Semiconductor package substrates require high-density connections to enhance signal transmission speed, and 2 xD packages equipped with fine redistribution layers (RDLs) with a Line/Space (L/S) of 2.0/2.0 μm or less have garnered significant attention. Traditionally, RDLs have been formed on wafers using liquid photoresists; however, there is a growing interest in forming RDLs on large panels to accommodate larger package sizes. However, applying liquid photoresists to large panels is challenging because of issues such as panel-specific warpage. To address this issue, dry film resists, which display high panel compatibility, have been highlighted, although they suffer from resolution limitations.