"Our lab staff have completed the initial cross-sectioning work for our IMX260 project and we have a substantial update to share: the Sony IMX260 is, in fact, a stacked chip CMOS image sensor! As mentioned, we had expected to find through silicon vias (TSVs) consistent with Sony’s Exmor RS technology platform. Our early teardown results revealed what appeared to be a conventional Sony non-stacked back-illuminated (Exmor R) chip. After going deeper inside, we see that Sony is leading the digital imaging sector into an era of hybrid bonding. It’s not currently known if Sony considers this an extension of its Exmor RS platform, or if the IMX260 marks the first of a new (as of now unannounced) family of back-illuminated image sensors. For now we consider the IMX260 to be a 3rd generation Exmor RS chip.
Our cross-section reveals a 5 metal (Cu) CMOS image sensor (CIS) die and a 7 metal (6 Cu + 1 Al) image signal processor (ISP) die. The Cu-Cu vias are 3.0 µm wide and have a 14 µm pitch in the peripheral regions. In the active pixel array they are also 3.0 µm wide, but have a pitch of 6.0 µm. Note that in the images we’ve included we do see connections from the Cu-Cu via pads to both CIS and ISP landing pads."
