Patent ID: 7736801

Claim:
A film covered electric device comprising: an electric device element to which a positive pole lead and a negative pole lead are connected; and a casing film comprising a thermally sealable resin layer wrapped around said electric device element such that the leads extend from at least one side of the film, the casing film having a thermally sealed area in which opposing surfaces of the film are thermally sealed around said electric device element, wherein said casing film has a cup area for receiving said electric device element therein, whereby a thermally sealed area is positioned outside of the cup area, and disposed within a range of the thickness of the electric device element, at least one of the sides of said thermally sealed casing film, from which said leads are not extended, is formed with a contact zone between the thermally sealed area and the electric device element, in which opposing surfaces of the casing film are directly opposing without intervention of said electric device element and are in contact with each other without being thermally sealed, a length L 2 of the contact zone in a direction parallel to a side of the electric device element is at least half of a length L 1 from one end to the other end of an inner edge of said thermally sealed area on the side formed with the contact zone, in a direction parallel to L 2 , and an angle formed by the surfaces of the casing film opposing each other in the contact zone is held at substantially zero degrees at a root of the thermally sealed area.