US 7,579,111 B2
Film-covered electric device having pressure release opening
Masatomo Mizuta, Tsukuba (Japan); Hiroshi Yageta, Tsukuba (Japan); Makihiro Otohata, Tsukuba (Japan); Kiyokazu Oikawa, Tsukuba (Japan); and Toshihiko Mankyu, Tsukuba (Japan)
Assigned to NEC Corporation, Tokyo (Japan)
Filed on Jul. 31, 2007, as Appl. No. 11/831,209.
Application 11/831209 is a continuation of application No. 11/034715, filed on Jan. 14, 2005, granted, now 7,267,906.
Claims priority of application No. 2004-009230 (JP), filed on Jan. 16, 2004.
Prior Publication US 2008/0008936 A1, Jan. 10, 2008
This patent is subject to a terminal disclaimer.
Int. Cl. H01M 2/12 (2006.01)
U.S. Cl. 429—185  [428/76] 12 Claims
OG exemplary drawing
 
1. A film-covered electric device having an electric device element, and a casing film arranged for enclosing said electric device element to seal said electric device element, said casing film comprising:
a sealing area formed by thermally fusing the facing surfaces of said casing film together throughout the perimeter of said casing film around the periphery of said electric device element;
an electric device element receiving part formed inside said sealing area as a space for encapsulating said electric device element;
at least one unfused portion communicating with said electric device element receiving part, and having a cove shape that opens to said electric device element receiving part;
a sealed stress concentrating portion touching said unfused portion and which concentrates the peeling stress of said casing film, the peeling stress being generated by the expansion of said electric device element receiving part according to the rise of inside pressure of said electric device element receiving part; and
a pressure release part formed within said sealed stress concentrating portion for opening the inside of said electric device element receiving part to the outside thereof by peeling said casing film at said sealed stress concentrating portion.