Inductive device

Abstract

An inductive device includes an insulating layer, a lower magnetic layer, and an upper magnetic layer that are formed such that the insulating layer does not separate the lower magnetic layer and the upper magnetic layer at the outer edges or wings of the inductive device. The lower magnetic layer and the upper magnetic layer form a continuous magnetic layer around the insulating layer and the conductors of the inductive device. Magnetic leakage paths are provided by forming openings through the upper magnetic layer. The openings may be formed through the upper magnetic layer by semiconductor processes that have relatively higher precision and accuracy compared to semiconductor processes for forming the insulating layer such as spin coating. This reduces magnetic leakage path variation within the inductive device and from inductive device to inductive device.

What is claimed is: 
     
         1 . A method, comprising:
 forming a first magnetic layer on one or more portions, of a second magnetic layer, that are over one or more insulating layers and one or more conductors; and   removing one or more portions, of the first magnetic layer, to form one or more openings in the first magnetic layer.   
     
     
         2 . The method of  claim 1 , wherein the second magnetic layer has a first insulating layer, of the one or more insulating layers, on at least a portion of a surface of the second magnetic layer. 
     
     
         3 . The method of  claim 1 , wherein removing the one or more portions of the first magnetic layer comprises:
 forming a photoresist layer on the first magnetic layer;   patterning the photoresist layer; and   etching, after patterning the photoresist layer, the one or more portions of the first magnetic layer.   
     
     
         4 . The method of  claim 1 , further comprising:
 forming the one or more conductors on a first insulating layer of the one or more insulating layers,   forming a second insulating layer, of the one or more insulating layers, on the first insulating layer and the one or more conductors; and   forming the first magnetic layer to cover the second insulating layer and the one or more portions of the second magnetic layer.   
     
     
         5 . The method of  claim 1 , wherein removing the one or more portions of the first magnetic layer comprises:
 determining, based on one or more performance parameters for an inductive device, at least one of:
 a respective shape for each of the one or more openings, 
 a respective size for each of the one or more openings, or 
 a respective location in the first magnetic layer for each of the one or more openings; and 
   removing the one or more portions of the first magnetic layer to form the one or more openings based on the at least one of:
 the respective shape for each of the one or more openings, 
 the respective size for each of the one or more openings, or 
 the respective location in the first magnetic layer for each of the one or more openings. 
   
     
     
         6 . The method of  claim 5 , wherein the one or more performance parameters include at least one of a maximum inductance for the inductive device or a saturation current for the inductive device. 
     
     
         7 . The method of  claim 5 , wherein a shape of an opening of the one or more openings includes a trench; and
 wherein a size of the opening includes a length parameter of the trench, a width parameter of the trench, and a depth parameter of the trench.   
     
     
         8 . A method, comprising:
 forming a first insulating layer on a first magnetic layer;   forming a conductive layer on the first insulating layer;   forming a second insulating layer over the conductive layer,   forming a second magnetic layer on the second insulating layer and one or more portions of the first magnetic layer; and   forming one or more openings through the second magnetic layer.   
     
     
         9 . The method of  claim 8 , further comprising:
 removing, based on forming the second insulating layer, one or more portions of the second insulating layer,
 wherein the one or more openings are formed via the one or more portions removed from the second insulating layer. 
   
     
     
         10 . The method of  claim 9 , wherein the one or more portions of the second insulting layer are removed via a patterned photoresist layer. 
     
     
         11 . The method of  claim 8 , wherein the conductive layer is formed via at least one of:
 a chemical vapor deposition process,   a physical vapor deposition process, or   a plating process.   
     
     
         12 . The method of  claim 8 , wherein the conductive layer is formed via a patterned photoresist layer. 
     
     
         13 . The method of  claim 8 , wherein the second insulating layer is further formed on one or more portions of the first insulating layer. 
     
     
         14 . A method, comprising:
 forming a first magnetic layer on a first insulating layer, a second insulating layer, and a second magnetic layer,
 wherein the first insulating layer and the second insulating layer encapsulate one or more conductors; and 
   forming one or more openings through the second magnetic layer and over the one or more conductors.   
     
     
         15 . The method of  claim 14 , further comprising:
 forming a photoresist layer on the first magnetic layer,
 wherein the one or more openings are formed via a pattern of the photoresist layer; and 
   removing the photoresist layer.   
     
     
         16 . The method of  claim 14 , wherein the one or more openings are a plurality of holes. 
     
     
         17 . The method of  claim 16 , wherein the one or more holes are a single trench. 
     
     
         18 . The method of  claim 14 , wherein forming the one or more openings comprises:
 determining, based on one or more performance parameters for an inductive device, at least one of:
 a respective shape for each of the one or more openings, 
 a respective size for each of the one or more openings, or 
 a respective location in the first magnetic layer for each of the one or more openings; and 
   forming the one or more openings based on the at least one of:
 the respective shape for each of the one or more openings, 
 the respective size for each of the one or more openings, or 
 the respective location in the first magnetic layer for each of the one or more openings. 
   
     
     
         19 . The method of  claim 18 , wherein the one or more performance parameters includes a maximum inductance for the inductive device. 
     
     
         20 . The method of  claim 18 , wherein the one or more performance parameters includes a saturation current for the inductive device.