Fine Lines in High Yield (Part CXXVIII): HDI Trends and Developments

摘要

Traditional HDI (high density interconnect) structures feature microvias in so-called build-up layers. The microvias in adjacent build-up layers are off-set, or "staggered." Coreless structures, such as the ALIVH process can form staggered as well as "stacked" microvias. In addition to the ALIVH stacked microvia structures (Matsushita, see Figure 1), there are other stacked microvia processes such as the PALAP process (Denso, see Figure 2) and the FVSS process (Ibiden, see Figure 3) that are gaining traction in commercial applications. The ALIVH process has been a long-time favorite in Japanese cell phone boards.