Coil inductor for on-chip or on-chip stack

摘要

A coil inductor and buck voltage regulator incorporating the coil inductor are provided which can be fabricated on a microelectronic element such as a semiconductor chip, or on an interconnection element such as a semiconductor, glass or ceramic interposer element. When energized, the coil inductor has magnetic flux extending in a direction parallel to first and second opposed surfaces of the microelectronic or interconnection element, and whose peak magnetic flux is disposed between the first and second surfaces. In one example, the coil inductor can be formed by first conductive lines extending along the first surface of the microelectronic or interconnection element, second conductive lines extending along the second surface of the microelectronic or interconnection element, and a plurality of conductive vias, e.g., through silicon vias, extending in direction of a thickness of the microelectronic or interconnection element. A method of making the coil inductor is also provided.

主权项

1. A method of making an element having a coil inductor thereon, the element being configured for connection within a microelectronic package, the method comprising:
forming a continuous coil inductor on an element including at least one of semiconductor, glass or ceramic material, the element having a first and a second opposed surfaces and a thickness between the first and the second surfaces of less than 1000 microns, the continuous coil inductor including first electrically conductive lines extending along the first surface, second electrically conductive lines extending along the second surface, and a plurality of conductive vias extending in a direction between the first and second surfaces and coupling the first and second electrically conductive lines, wherein the plurality of conductive vias and the first and second electrically conductive lines are arranged to form a first helical coil intertwined with a second helical coil in a double helix structure, wherein when energized, the continuous coil inductor has magnetic flux extending in a direction parallel to the first and second surfaces and whose peak magnetic flux is disposed between the first and second surfaces, wherein an output end of the continuous coil inductor is displaced from an input end of the coil inductor by no more than 10% of a length of a path of the magnetic flux between the input end and the output end of the continuous coil inductor, and wherein the continuous coil inductor includes a first plurality of turns configured to direct the magnetic flux in a first straight path extending in a first direction, and includes a second plurality of turns configured to direct the magnetic flux in a second straight path parallel to and extending in a second direction opposite the first direction, the first straight path being separated from the second straight path by a distance approximately equal to the displacement between the input end and the output end.