US 12,237,366 B2
Thin film capacitor and electronic circuit substrate having the same
Daiki Ishii, Tokyo (JP); Yoshihiko Yano, Tokyo (JP); Yuki Yamashita, Tokyo (JP); Kenichi Yoshida, Tokyo (JP); and Tetsuhiro Takahashi, Tokyo (JP)
Assigned to TDK Corporation, Tokyo (JP)
Appl. No. 18/012,820
Filed by TDK Corporation, Tokyo (JP)
PCT Filed Dec. 24, 2020, PCT No. PCT/JP2020/048396
§ 371(c)(1), (2) Date Dec. 23, 2022,
PCT Pub. No. WO2022/004020, PCT Pub. Date Jan. 6, 2022.
Claims priority of provisional application 63/045,579, filed on Jun. 29, 2020.
Prior Publication US 2023/0260713 A1, Aug. 17, 2023
Int. Cl. H01G 4/005 (2006.01); H01G 2/06 (2006.01); H01G 4/008 (2006.01); H01G 4/01 (2006.01); H01G 4/012 (2006.01); H01G 4/06 (2006.01); H01G 4/10 (2006.01); H01G 4/12 (2006.01); H01G 4/228 (2006.01); H01G 4/33 (2006.01); H01L 25/16 (2023.01); H01L 49/02 (2006.01); H05K 1/18 (2006.01); H01G 4/252 (2006.01); H01L 23/00 (2006.01)
CPC H01L 28/75 (2013.01) [H01G 2/065 (2013.01); H01G 4/005 (2013.01); H01G 4/008 (2013.01); H01G 4/01 (2013.01); H01G 4/012 (2013.01); H01G 4/06 (2013.01); H01G 4/10 (2013.01); H01G 4/1209 (2013.01); H01G 4/1218 (2013.01); H01G 4/1254 (2013.01); H01G 4/228 (2013.01); H01G 4/33 (2013.01); H01L 25/16 (2013.01); H01L 28/84 (2013.01); H05K 1/18 (2013.01); H01G 4/252 (2013.01); H01L 24/16 (2013.01); H01L 2224/16227 (2013.01); H01L 2924/19015 (2013.01); H01L 2924/19041 (2013.01); H01L 2924/19102 (2013.01); H01L 2924/19103 (2013.01); H05K 2201/10015 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A thin film capacitor comprising:
a metal foil having one roughened main surface;
a dielectric film covering the one main surface of the metal foil and having an opening through which the metal foil is partly exposed;
a first electrode layer contacting the metal foil through the opening; and
a second electrode layer contacting the dielectric film without contacting the metal foil,
wherein the metal foil has other main surface positioned on a side opposite to the one main surface and a side surface connecting the one main surface and the other main surface,
wherein an angle formed by the other main surface and the side surface is more than 20° and less than 80°,
wherein the first and second electrode layers are separated from each other by an annular slit,
wherein the first electrode layer is provided in a first area surrounded by the slit,
wherein the second electrode layer is provided in a second area positioned outside the slit,
wherein the thin film capacitor further comprises:
a first insulating member provided inside the slit and positioned between the first and second electrode layers; and
a second insulating member provided on the one main surface of the metal foil and surrounding the second electrode layer, and
wherein a virtual straight line extending along the side surface does not interfere with the second insulating member.