Integrated inductor apparatus

An integrated inductor includes a first coil, a second coil, a third coil and a fourth coil. The first coil is disposed on a first layer of an integrated circuit structure. The second coil is disposed on the first layer and adjacent to the first coil, in which the first coil and the second coil have same number of turns. The third coil is disposed on a second layer of the integrated circuit structure and above the first coil. The fourth coil is disposed on the second layer and above the second coil, in which the third coil and the fourth coil have same number of turns. The first coil is coupled to and interlaced with the fourth coil disposed on the second layer. The second coil is coupled to and interlaced with the third coil disposed on the second layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Taiwan Application Serial Number 106132291, filed on Sep. 20, 2017, which is herein incorporated by reference.

BACKGROUND

Field of Invention

Present disclosure relates to an integrated circuit, especially an inductor apparatus in the integrated circuit.

Description of Related Art

Nowadays, inductor apparatuses are essential in an integrated circuit. In these inductor apparatuses, since an eight-shaped inductor has a symmetric electrical characteristic and has two terminals able to generate magnetic fields having opposite directions, the magnetic fields generated by the eight-shaped inductor are offset with each other. As such, the eight-shaped inductor introduces fewer impacts on other parts in the integrated circuit. Therefore, the eight-shaped inductor is widely applied in an integrated circuit, especially as a part of transformers. However, in current approaches, an eight-shaped inductor is difficult to be formed to have a complete symmetric electrical characteristic.

DETAILED DESCRIPTION

FIG. 1is a schematic diagram of an integrated inductor apparatus according to one embodiment of present disclosure. In the embodiment, a first coil100and a second coil200are illustrated, and both the coils are planar coils. The first coil100and the second coil200are disposed on a first layer of an integrated circuit board (not shown). As shown inFIG. 1, a first imaginary line L1, which is extended from a first orientation of the first layer to a second orientation of the first layer, is illustrated on the first layer of the integrated circuit board. As demarcated by the first imaginary line L1, the first layer of the integrated circuit board is substantially divided into a first area A and a second area B, in which the first area A has a first center CA and the second area B has a second center CB. The first coil100is disposed in the first area A and substantially centered at the first center CA. The second coil200is disposed in the second area B and substantially centered at the second center CB.

In the embodiment, the first area A has a first side, a second side, a third side, and a fourth side. As illustrated inFIG. 1, the first side is the topside of the first area A, the second side is the downside of the first area A, the third side is the left side of the first area A, and the fourth side is the right side of the first area A. Similarly, the second area B has a first side, a second side, a third side and a fourth side as well. The arrangements of the four sides of the second area B are the same as those of the four sides of the first area A. In this case, the fourth side of the first area A is adjacent to the third side of the second area B.

In the embodiment, the first coil100includes two turns which are a first turn located at an inner side and a second turn located at an outer side. In the first area A, the second turn of the first coil100winds around the first turn of the first coil100. The first turn of the first coil100has a beginning end101. The first turn of the first coil100is disposed, from the beginning end101and the first side, the third side, the second side, and the fourth side of the first area A to a reference point T1, around the first center CA in a counterclockwise direction, and is then arranged to the second turn of the first coil100via the reference point T1. Metallic segments of the second turn of the first coil100are disposed, from the reference point T1and the first side, the third side, the second side, and the fourth side of the first area A to a first connector C1, around the first center CA in the counterclockwise direction, and is then coupled to the first connector C1. A first port P1is located around a top-right corner of the first area A and outside the second turn of the first coil100. The beginning end101of the first coil100is coupled to the first port P1through a first connecting line (not shown). The first connecting line is disposed on another layer of the integrated circuit board that is different from the first layer. The beginning end101of the first coil100is coupled to the first connecting line through a via, and the first port P1is coupled to the first connecting line through another via. An end terminal of the first coil100is coupled to the first connector C1. The first connector C1is located outside the second turn of the first coil100and around the top-right corner of the first area A. The first connector C1is vertically disposed on the first layer and between the first area A and the second area B.

In the embodiment, the second coil200includes two turns which are a first turn located at an inner side and a second turn located at an outer side. In the second area B, the second turn of the second coil200winds around the first turn of the second coil200. The first turn of the second coil200has a beginning end201. The first turn of the second coil200is disposed, from the beginning end201and the second side, the fourth side, the first side, and the third side of the second area B to a reference point T2, around the second center CB in a counterclockwise direction, and is then arranged to the second turn of the second coil200via the reference point T2. Metallic segments of the second turn of the second coil200are disposed from the reference point T2and the second side, the fourth side, the first side, and the third side of the second area B to a second connector C2, around the second center CB in a counterclockwise direction, and is then coupled to the second connector C2. A second port P2is located around a down-left corner of the second area B and outside the second turn of the second coil200. The beginning end201of the second coil200is coupled to the second port P2through a second connecting line (not shown). The second connecting line is disposed on another layer of the integrated circuit board that is different from the first layer. The beginning end201of the second coil200is coupled to the second connecting line through a via, and the second port P2is coupled to the second connecting line through another via. An end terminal of the second coil200is coupled to the second connector C2. The second connector C2is located outside the second turn of the second coil200and around the down-left corner of the second area B. The second connector C2is vertically disposed on the first layer and between the first area A and the second area B.

FIG. 2is a schematic diagram of an integrated inductor apparatus according to one embodiment of present disclosure. In the embodiment, a third coil300and a fourth coil400are illustrated, and both the coils are planar coils. The third coil300and the fourth coil400are disposed on a second layer of the integrated circuit board, in which the second layer is disposed above the first layer. As shown inFIG. 2, a second imaginary line L2, which is extended from a first orientation of the second layer to a second orientation of the second layer, is illustrated. The second imaginary line L2is parallel to the first imaginary line L1inFIG. 1. As demarcated by the second imaginary line L2, the second layer of the integrated circuit board is substantially divided into a third area C and a fourth area D, in which the third area C has a third center CC and the fourth area D has a fourth center CD. The third area C is disposed above the first area A, and the fourth area D is disposed above the second area B. The third coil300is disposed in the third area C and substantially centered at the third center CC. The fourth coil400is disposed in the fourth area D and substantially centered at the fourth center CD.

In the embodiment, each of the third area C and the fourth area D has a first side, a second side, a third side, and a fourth side. The arrangements of the four sides of the third area C or the fourth area D are the same as the arrangements of the four sides of the first area A or the second area B inFIG. 1. In this case, the fourth side of the third area C is adjacent to the third side of the fourth area D.

In the embodiment, the third coil300includes two turns which are a first turn located at an outer side and a second turn located at an inner side. In the third area C, the second turn of the third coil300is disposed around the first turn of the third coil300. The first turn of the third coil300has a beginning end which is coupled to the second connector C2inFIG. 1. From the second connector C2and the second side, the third side, the first side, and the fourth side of the third area C to a reference point T3, the first turn of the third coil300is disposed around the third center CC in a clockwise direction, and is then connected/mounted to the second turn of the third coil300via the reference point T3. Metallic segments of the second turn of the third coil300are disposed, from the reference point T3and the second side, the third side, the first side, and the fourth side of the third area C to an end terminal301, around the third center CC in the clockwise direction. The end terminal301is coupled to a third port P31which is disposed on the first layer inFIG. 1. The third port P31is located outside the second turn of the first coil100and around a down-right corner of the first area A. The end terminal301of the third coil300is coupled to a connecting point P32disposed on the first layer, and the connecting point P32is coupled to the third port P31through a third connecting line (not shown). The third connecting line is disposed on another layer of the integrated circuit board that is different from the second layer. The end terminal301of the third coil300is coupled to the connecting point P32through a via, and the third port P31is coupled to the third connecting line through another via.

In the embodiment, the fourth coil400includes two turns which are a first turn located at an outer side and a second turn located at an inner side. In the fourth area D, the second turn of the fourth coil400is winds around the first turn of the fourth coil400. The first turn of the fourth coil400has a beginning end, in which the beginning end is coupled to the first connector C1shown inFIG. 1. The first turn of the fourth coil400is disposed, from the beginning end and the first side, the fourth side, the second side, and the third side of the fourth area D to a reference point T4, around the fourth center CD in a clockwise direction, and is then arranged to the second turn of the fourth coil400via the reference point T4. Metallic segments of the second turn of the fourth coil400are disposed, from the reference point T4, and the first side, the fourth side, the second side, and the third side of the fourth area D to an end terminal401, around the fourth center CD in a clockwise direction, and is then coupled to a fourth port P41. The fourth port P41is disposed on the first layer shown inFIG. 1. The fourth port P41is located around an up-left corner of the second area B and outside the second turn of the second coil200. The end terminal401of the fourth coil400is coupled to a connecting point P42disposed on the first layer, and the connecting point P42is coupled to the fourth port P41through a fourth connecting line (not shown). The fourth connecting line is disposed on another layer of the integrated circuit board that is different from the second layer. The end terminal401of the fourth coil400is coupled to the connecting point P42through a via, and the fourth port P41is coupled to the fourth connecting line through another via.

FIG. 3is a schematic diagram of an integrated inductor apparatus according to one embodiment of present disclosure. The figure illustrates a stacked integrated inductor apparatus formed by the integrated inductor apparatus shown inFIG. 1andFIG. 2. With respect toFIG. 1andFIG. 2, like elements inFIG. 3are designated with the same reference numbers for ease of understanding. In the embodiment, the second layer of the integrated circuit board is disposed above and in parallel with the first layer. The third area C of the second layer is disposed above the first area A of the first layer, and the fourth area D of the second layer is disposed above the second area B of the first layer. In the embodiment, as shown inFIGS. 1-2, the first coil100disposed on the first layer is coupled to and interleaved with the fourth coil400disposed on the second layer via the first connector C1, and the second coil200disposed on the first layer is coupled to and interleaved with the third coil300disposed on the second layer via the second connector C2. When being passed through by a current, the first coil100and the third coil300can generate opposite magnetic fields that are offset each other. When being passed through by a current, the second coil200and the fourth coil400can generate opposite magnetic fields that are offset each other.

FIG. 4is a schematic diagram of an integrated inductor apparatus according to one embodiment of present disclosure. In the embodiment, a first coil500and a second coil600are disposed on the first layer of the integrated circuit board. The patterns of the first coil500and the second coil600are identical to those of the first coil100and the second coil200inFIG. 1. The difference between this embodiment and the embodiment ofFIG. 1is that first coil500has a beginning end501coupling to a first port P5and the second coil600has a beginning end601coupling to a second port P6. Moreover, the first coil500is coupled to a first connector C3, and the second coil600is coupled to a second connector C4. The location of a reference point T5inFIG. 4is the same as that of the reference point T1inFIG. 1. The location of a reference point T6inFIG. 4is the same as that of the reference point T2inFIG. 1.

FIG. 5is a schematic diagram of an integrated inductor apparatus according to one embodiment of present disclosure. In the embodiment, a third coil700and a fourth coil800are disposed on the second layer of the integrated circuit board. As demarcated by the second imaginary line L2, the second layer of the integrated circuit board is substantially divided into a third area C and a fourth area D. Each of the third area C and the fourth area D has a first side, a second side, a third side, and a fourth side. The arrangements of the four sides of the third area C or the fourth area D are the same as those in the embodiment ofFIG. 2.

In this embodiment, the third coil700has one turn. The turn of the third coil700has a beginning end coupling to the second connector C4inFIG. 4. The turn of the third coil700is substantially centered at the third center CC. The turn of the third coil700is disposed, from the second connector C4and the second side, the third side, the first side, and the fourth side of the third area C to an end terminal701, around the third center CC in a clockwise direction, and is then coupled to the end terminal701. The end terminal701is coupled to a third port P71disposed on the first layer inFIG. 4. The end terminal701is coupled to a connecting point P72disposed on the first layer, and is then coupled to the third port P71through a third connecting line (not shown) via the connecting point P72. The third connecting line is disposed on another layer that is different from the second layer.

In this embodiment, the fourth coil800has one turn. The turn of the fourth coil800has a beginning end coupling to the first connector C3. The turn of the fourth coil800is disposed, from the first connector C3and the first side, the fourth side, the second side, and the third side of the fourth area D to an end terminal801, around the fourth center CD in a clockwise direction, and is then coupled to the end terminal801. The end terminal801is coupled to a fourth port P81that is disposed on the first layer. The end terminal801is coupled a connecting point P82disposed on the first layer, and is then coupled to the fourth port P81through a fourth connecting line (not shown) via the connecting point P82. The fourth connecting line is disposed on another layer that is different from the second layer.

FIG. 6is a schematic diagram of an integrated inductor apparatus according to one embodiment of present disclosure. The figure illustrates a stacked integrated inductor apparatus formed by the integrated inductor apparatuses shown inFIG. 4and inFIG. 5. With respect toFIGS. 1 and 2, like elements inFIG. 6are designated with the same reference numbers for ease of understanding. In the embodiment, the second layer of the integrated circuit board is disposed above and in parallel with the first layer. The third area C of the second layer is disposed above the first area A of the first layer, and the fourth area D of the second layer is disposed above the second area B of the first layer. In the embodiment, the first coil500disposed on the first layer is coupled to and interleaved with the fourth coil800disposed on the second layer via the first connector C3, and the second coil600disposed on the first layer is coupled to and interleaved with the third coil700disposed on the second layer via the second connector C4.

FIG. 7is a schematic diagram shows an experiment result of an integrated inductor apparatus according to one embodiment of present disclosure. The horizontal axis inFIG. 7indicates a frequency. The vertical axis indicates the value of Q factors and the value of inductances. The arrangements of the integrated inductor apparatus which is measured inFIG. 7and the windings thereof are given in the above embodiments, in which the width of each winding is about 2 μm and the length of a radius of each winding is about 25 μm. The curve Q shows the Q factor obtained from one integrated inductor apparatus in aforementioned embodiments. In fact, the curve Q is the Q factor measured from an inductor structure formed with the first coil and the fourth coil, and the Q factor measured from an inductor structure formed with the second coil and the third coil will be identical to the curve Q. As shown inFIG. 7, the Q factors of the twin inductor of the present disclose are symmetrical to each other.

With continued reference toFIG. 7, the curve L indicates the inductance value of the integrated inductor apparatus of the above embodiments. Similarly, the inductance value measured from the inductor structured formed with the first coil and the fourth coil and the inductance value measured from the second coil and the third coil are identical to the curve L. Accordingly, the Q factors and the inductance values measured from two inductor structures in the inductor apparatus of the present disclosure are very symmetric and have more symmetry than current approaches.