Integrated circuit assemblies with rigid layers used for protection against mechanical thinning and for other purposes, and methods of fabricating such assemblies

A manufacturing method comprising:

• obtaining an assembly comprising a first structure and one or more modules, wherein:
• the first structure comprises first circuitry comprising one or more first contact pads at a top of the first structure;
• the one or more modules are attached to a top surface of the first structure and electrically connected to at least one first contact pad, each module comprising at least one semiconductor integrated circuit;
• after obtaining the assembly, forming a first electrically insulating layer on the top surface of the first structure;
• forming a second layer overlying the first electrically insulating layer, wherein the second layer has a lower room-temperature elastic modulus than the first electrically insulating layer;
• and
• thinning the first structure from a bottom of the first structure while the first electrically insulating layer is present on said top surface of the first structure;
• wherein at least one of the following is true:
• (a) the first electrically insulating layer is inorganic;
• (b) the first electrically insulating layer is a material different from any material found at an interface between the first structure and at least one of the one or more modules;
• (c) during the thinning, the first electrically insulating layer covers all of that portion of said top surface which is not occupied by the one or more modules;
• (d) the one or more modules comprise one or more first modules, the assembly comprising underfill between the first structure and each first module, the underfill extending laterally beyond each first module, and during the thinning the first electrically insulating layer covers all of that portion of said top surface which is not occupied by the one or more modules and not covered by the underfill.