Novel plating photoresist development for advanced packaging

As electronic devices are getting smaller and thinner, the packaging structures for semiconductors are becoming more complex. Packaging technologies such as FO-WLP (Fan-Out Wafer Level Packaging), 3D-TSV, 2.5D, PoP (package on package) and Flip-chip wafer bumping are predominant now, but new technologies that offer better levels of integration and lower package thickness are inevitable. To meet these new market trends, chemically amplified (CA) photoresists for plating with both higher resolution and better tolerance to plating solution are required. To satisfy these requirements, we focused on resin which is one of the major components of chemically amplified resists. In this study, we found that the molecular weight (Mw) and glass transition temperature (Tg) of resin was key to plating resistance.