Canon Patent Application: Stacked Sensor Lamination

In this patent application, Canon describes how they would seal the two substrates together.  They are concerned, in this patent, about water infiltrating between the layers.  Makes sense, the last thing you would want slowly see liquid seap in between the two layers of your sensors.  Nothing good happens in this case.  While for most camera sensors, this isn't much of a problem - I doubt even wet cleaning your sensor would have an effect, there are certainly cases of high humity environments that could cause problems over time to a sensitive sensor.  Canon states;

It is a solid-state image sensor configured by laminating a material and the second member, and has a seal portion that suppresses the infiltration of water into the plurality of pixels and the peripheral circuit from the outside of the solid-state image sensor. The seal portion has a first seal portion arranged on the first member and a second seal portion arranged on the second member, and a part of the first seal portion and the second seal portion. It is in contact with a part of the department.

Canon has continued to work on stacked sensors over the course of the time I've been reporting on patents.  This certainly shows that they haven't stopped, and with the announcement of the IP patent licensing of Invensas DBI hybrid bonding it certainly seems that Canon is getting quite serious about bringing stacked sensors to the fold.

Japan Patent Application 2020-191467