Patent ID: 8749337
Filing Date: 2014-06-10
Classification: H01F,H01L,Y10T

Abstract:
1. An electric coil device comprising: a spiral comprising a plurality of electro-conductive turns and an isolation layer between the turns, the isolation layer comprising a spiral trench of varying width formed of a surrounding electrically isolating bulk, the electro-conductive turns comprising an electro-conductive material at least partly filling said spiral trench; and connection feeds in and out of the spiral, wherein the spiral is generally planar defining a coil plane and wherein the feeds extend both upward and downward from said coil plane, and wherein the trench which varies in height includes a peripheral portion, an intermediate portion and a central portion and wherein the cross-sectional height of the intermediate portion is greater than the cross-sectional heights, e.g. common cross-sectional height if equal, of the peripheral and central portions.