3D ICs in the real world

There has been much discussion (hype, even!) of 3D chip stacking taking over when the device shrinkage described by Moore´s Law comes to an end. To hear some industry commentators, through-silicon vias (TSVs) will enable a revolution in performance and enable the next several generations of electronics evolution. In fact the transition to commercial 3D stacking of heterogeneous components is taking much longer than was predicted a few years ago. While commodity parts such as flash memory or DRAM have achieved impressive levels of density, true system-in-package parts are a rarity, or limited to niche markets such as MEMS or image sensors. The use of TSVs has so far been limited to products such as image sensors, high-end FPGAs, and a minority of MEMS devices. However, the packaging industry has been making great strides in multi-chip packaging, just not in the directions that have received the media attention. The rapid evolution of mobile devices has driven major changes in the packaging arena, and there have been remarkable developments as a consequence. Chipworks, as a supplier of competitive intelligence to the semiconductor and electronics industries, has monitored the evolution of chip packaging as new developments come into commercial production. Chipworks has obtained parts from the leading edge products, and performed structural analyses to examine the new features of the devices. The paper reviews some of the different packaging technologies that we have seen in recent years, and looks at some examples of both the `new normal´ and unusual packages in use.