Miniature inductor for integrated circuits and devices

An electromagnetic device comprising:

• a semiconductor substrate having one or more electrical circuits integrally defined therein;
• a magnetic shield layer disposed over the substrate,
• a first layer of spaced apart conductive strips disposed over the shield layer;
• a magnetic core layer superimposed of the first layer of conductive strips;
• a second layer of spaced apart conductive strips superimposed on the magnetic core layer, portions of the conductive strips of the second layer connected to portions of the conductive strips of the first layer to form a first substantially helical electrical path which spirals about at least one portion of the magnetic core layer for generating or detecting magnetic flux in said one portion of the core layer, and wherein said magnetic shield layer shields one or more of said electrical circuits from the flux generated or detected by the first helical electrical path;
• and a movable member which is moved by a force induced by the magnetic flux of the magnetic core layer.

An electromagnetic device comprising:

• a semiconductor substrate having one or more electrical circuits integrally defined therein;
• a magnetic shield layer disposed over the substrate,
• a first layer of spaced apart conductive strips disposed over the shield layer;
• a magnetic core layer superimposed on the first layer of conductive strips;
• a second layer of spaced apart conductive strips superimposed on the magnetic core layer, portions of the conductive strips of the second layer connected to portions of the conductive strips of the first layer to form a first, substantially helical electrical path which spirals about at least one portion of the magnetic core layer for generating or detecting magnetic flux in said one portion of the core layer, wherein said magnetic shield layer shields one or more of said electrical circuits from the flux generated or detected by the first helical electrical path and wherein the one or more electrical circuits of the semiconductor substrate include a plurality of transistors, the helical electrical path has three connection terminals, and at least two of the transistors are electrically coupled to a corresponding two of the connection terminals.

An electromagnetic device comprising:

• a semiconductor substrate having one or more electrical circuits integrally defined therein;
• a magnetic shield layer disposed over the substrate,
• a first layer of spaced apart conductive strips disposed over the shield layer;
• a magnetic core layer superimposed on the first layer of conductive strips;
• a second layer of spaced apart conductive strips superimposed on the magnetic core layer, portions of the conductive strips of the second layer connected to portions of the conductive strips of the first layer to form a first, substantially helical electrical path which spirals about at least one portion of the magnetic core layer for generating or detecting magnetic flux in said one portion of the core layer, wherein said magnetic shield layer shields one or more of said electrical circuits from the flux generated or detected by the first helical electrical path,
• wherein the magnetic core layer includes a substantially annular section having two or more helical electrical paths spiraling there about, said two or more helical electrical paths being electrically isolated from one another, and wherein:
• the number of electrical circuit integrally defined in the semiconductor substrate is more than one;
• the semiconductor substrate includes substrate isolation means for subdividing the plural electrical circuits of the semiconductor substrate into at least first and second electrically isolated circuit portions and
• the substantially annular section of the magnetic core layer is positioned to define a magnetic coupling path extending across the substrate isolation means to magnetically couple the first circuit portion to the second circuit portion.

A method for forming an integrated electromagnetic device comprising:

• forming a layer of polyimide on or above the semiconductor substrate;
• patterning the polyimide layer to define vias extending though the polyimide layer;
• depositing a metal film on the patterned polyimide layer such that a portion of the deposited metal film adheres to the bottoms of the vias;
• and
• removing portions of the metal film which have not adhered to the bottoms of the vias;
• providing a semiconductor substrate having an integrated circuit integrally defined therein;
• providing a bonding layer;
• forming a first winding layer on the bonding layer of spaced apart, electrically conductive strips on the substrate, the first winding layer being composed of a first electrically conductive material;
• forming a magnetic core above the first layer of conductive strips, the magnetic core being shaped so as to permit the formation of a helical electrical path thereabout where the helical electrical path is to include the conductive strips of the first layer;
• forming a second winding layer of spaced apart, electrically conductive strips above the magnetic core, the second winding layer being composed of a second electrically conductive material;
• and
• connecting the conductive strips of the first and second winding layers so as to define a substantially helical electrical path spiraling about the magnetic core;
• wherein the forming of the first and second winding layers includes electroplating at least some of at least one of the first and second electrically conductive materials which form the respective conductive strips of the first and second winding layers.