A flexible electronic device comprising: a flexible case frame (10, 11, 12), having a radius of available flexure; a flexible substrate, disposed in an inner space defined by the case frame (10, 11, 12); a flexible battery pack, disposed in the inner space; and a flexible display, coupled to the flexible case frame (10, 11, 12); and positioned so that a display surface of the flexible display is exposed, wherein the case frame (10, 11, 12) comprises a plurality of intercoupled unit case frames configured to move relative to one another, CHARACTERISED IN THAT each of the plurality of unit case frames comprises: an elongate flat surface, defining a portion of a rear surface of the electronic device in an assembled state of the plurality of unit case frames; a first side surface and an opposing second side surface, each side surface (122; 123) extending perpendicularly from side-distal ends of the flat surface and defining portions of opposing side surfaces of the electronic device in an assembled state of the plurality of unit case frames; a coupler, protruding from a lateral end of the flat surface; and a seating end, recessing from a distal lateral end of the flat surface, the seating end formed at the distal lateral end in opposition to the coupler formed at the lateral end, wherein the coupler of a first of the plurality of unit case frames is configured to at least partially couple with the seating end of a second of the plurality of unit case frames that is adjacent to the first of the plurality, and the inner space accommodating the flexible substrate and the battery pack is defined by the flat surfaces and the first and opposing second side surfaces (122; 123) of the adjacent first and second of the plurality of unit case frames. a flexible case frame (10, 11, 12), having a radius of available flexure; a flexible substrate, disposed in an inner space defined by the case frame (10, 11, 12); a flexible battery pack, disposed in the inner space; and a flexible display, coupled to the flexible case frame (10, 11, 12); and positioned so that a display surface of the flexible display is exposed, wherein the case frame (10, 11, 12) comprises a plurality of intercoupled unit case frames configured to move relative to one another, CHARACTERISED IN THAT each of the plurality of unit case frames comprises: an elongate flat surface, defining a portion of a rear surface of the electronic device in an assembled state of the plurality of unit case frames; a first side surface and an opposing second side surface, each side surface (122; 123) extending perpendicularly from side-distal ends of the flat surface and defining portions of opposing side surfaces of the electronic device in an assembled state of the plurality of unit case frames; a coupler, protruding from a lateral end of the flat surface; and a seating end, recessing from a distal lateral end of the flat surface, the seating end formed at the distal lateral end in opposition to the coupler formed at the lateral end, an elongate flat surface, defining a portion of a rear surface of the electronic device in an assembled state of the plurality of unit case frames; a first side surface and an opposing second side surface, each side surface (122; 123) extending perpendicularly from side-distal ends of the flat surface and defining portions of opposing side surfaces of the electronic device in an assembled state of the plurality of unit case frames; a coupler, protruding from a lateral end of the flat surface; and a seating end, recessing from a distal lateral end of the flat surface, the seating end formed at the distal lateral end in opposition to the coupler formed at the lateral end, wherein the coupler of a first of the plurality of unit case frames is configured to at least partially couple with the seating end of a second of the plurality of unit case frames that is adjacent to the first of the plurality, and the inner space accommodating the flexible substrate and the battery pack is defined by the flat surfaces and the first and opposing second side surfaces (122; 123) of the adjacent first and second of the plurality of unit case frames.