Use of underfill tape in microelectronic components, and microelectronic components with cavities coupled to through-substrate vias

A structure comprising:

• a microelectronic component comprising a first surface with one or more first cavities and, for each first cavity, at least one first contact pad recessed in the first cavity;
• and
• an underfill tape attached to the first surface, the underfill tape at least partially covering each first cavity but not physically contacting any first contact pad.

A structure comprising:

• a substrate comprising a first surface and a second surface, and comprising one or more through-substrate vias (TSVs) each of which is a conductive via passing through the substrate;
• wherein the substrate comprises a cavity in at least one of the first and second surfaces and coupled to at least one TSV extending into the cavity, the cavity being configured to locally contain solder for attaching the TSV to a protruding contact pad of another microelectronic component.