Inductive structures for semiconductor integrated circuits

An inductive structure integrable with a semiconductor integrated circuit comprising:

• an electrically insulating substrate having opposed first and second surfaces;
• an electrical conductor disposed in a spiral spaced from the first surface of the substrate, the spiral including an external end disposed outside the spiral as a first lead and an internal end disposed within the spiral, said first spiral including at least two windings adjacent each other;
• and
• a plurality of electrically conducting, spaced apart posts disposed on the first surface of the substrate contacting and supporting the first spiral wherein each post supporting one winding is disposed intermediate two adjacent posts supporting an adjacent winding.

A transformer integrable with a semiconductor integrated circuit comprising:

• an electrically insulating semiconductor substrate having a first surface;
• a first electrical conductor disposed on the first surface of the substrate comprising a first winding having a first pair of leads;
• a first electrically insulating film disposed on the first electrical conductor;
• a second electrical conductor disposed on the electrically insulating film comprising a second winding having a second pair of leads, the first and second windings and the electrically insulating film including a common central opening wherein the pairs of leads of the first and second windings are oriented in different directions to minimize the coupling between the respective pairs of leads;
• and
• a magnetic material disposed on the surface of the substrate in the common central opening increasing the inductive coupling between the first and second windings.

A transformer integrable with a semiconductor integrated circuit comprising:

• an electrically insulating substrate having opposed first and second surfaces;
• a plurality of first electrically conducting vias passing through the substrate from the first to the second surface;
• at least one first and second electrical conductor respectively disposed on the first and second surfaces of the substrate, each of the first and second conductors electrically connecting two vias to form a first helical winding comprising the first and second electrical conductors and the first vias;
• first and second electrically conducting leads disposed on at least one of the first and second surfaces of the substrate respectively electrically connected to one of the first vias;
• first and second electrically insulating films disposed on the first and second surfaces of the substrate, respectively, at least partially covering the first and second electrical conductors and first and second leads;
• a plurality of second electrically conducting vias passing through the first and second electrically insulating films and the electrically insulating substrate;
• at least one third and fourth electrical conductor respectively disposed on the first and second electrically insulating films, each of the third and fourth conductors electrically connecting two of the second vias to form a second helical winding comprising the third and fourth electrical conductors and the second vias;
• and
• third and fourth electrically conducting leads disposed on at least one of the first and second electrically insulating films respectively electrically connected to one of the second vias.

A two terminal variable inductance element integrable with a semiconductor integrated circuit comprising:

• an electrically insulating substrate having opposed first and second surfaces;
• a first electrical conductor disposed in a first spiral on the first surface of the substrate;
• means for producing and controlling a variable electrical current flow through the first conductor;
• an electrically insulating film disposed on the first surface and the first spiral;
• and
• a second electrical conductor having first and second terminals, disposed in a second spiral on the electrically insulating film, and inductively coupled to the first spiral, the first and second terminals of the second electrical conductor constituting the terminals of the two terminal variable inductance element whereby the inductance between the first and second terminals is controlled by the electrical current flow through the first electrical conductor.

A variable inductance element integrable with a semiconductor integrated circuit comprising:

• an electrically insulating substrate having opposed first and second surfaces;
• an electrical conductor disposed in a first spiral on the first surface of the substrate;
• an electrically insulating film disposed on the first surface and the first spiral;
• a second electrical conductor disposed in a second spiral on the electrically insulating film and inductively coupled to the first spiral, each of the first and second spirals having respective first and second ends;
• an electrically conducting first via penetrating the electrically insulating film electrically connecting the first end of the first spiral to the first end of the second spiral;
• and
• an electrically conducting ground plane disposed on the second surface of the substrate and a second electrically conducting via passing through the substrate from the first to the second surface electrically connecting the second end of the first spiral to the ground plane.