In recent years, electronic devices such as mobile terminals represented by smart phones are increasingly developed to present high performance, multi-functionality, and the like, and accordingly, they are increasingly developed to be rapidly driven by a low voltage and a large current. As an electronic device is rapidly driven, in an electronic component such as an IC, a high frequency noise is generated by a switching device rapidly switching or the like. The noise has a negative effect on an operation of an electronic device, and accordingly, an anti-noise measure is required.
For example, Japanese Patent Laying-Open No. 10-163027 discloses an inductance element comprising a printed pattern laid on a printed circuit board and a magnetic body stuck in a vicinity of the printed pattern wherein the magnetic body can be partially cut and thus adjusted in a direction to reduce the printed pattern's inductance to adjust inductance successively with good precision. Japanese Patent Laying-Open No. 10-163027 discloses that by applying this inductance element to an electronic circuit, a low pass filter with good adjustment precision is obtained.
Furthermore, Japanese Utility Model Laying-open No. 61-66911 discloses a multilayer type bead chip inductor in which a conductor is disposed inside a ferrite sheet. Furthermore, as a measure against high frequency noise, there is also a measure using an inductor in the form of a multilayer coil for high frequency.
USPTO Backgrounds
USPTO Backgrounds