CN105304606B - Electronic device with two-plane type inductor - Google Patents

Abstract

The present invention discloses an electronic device including a first planar inductor and a second planar inductor. The first planar inductor at least includes a first annular structure and a second annular structure connected to each other, respectively generating a first magnetic field with a first direction and a second magnetic field with a second direction, the first direction being different from the second direction. The second planar inductor at least includes a third annular structure and a fourth annular structure connected to each other, respectively generating a third magnetic field with a third direction and a fourth magnetic field with a fourth direction, the third direction being different from the fourth direction. The first annular structure overlaps with at least a portion of the third annular structure to form a first overlapping area, and overlaps with at least a portion of the second annular structure and the fourth annular structure to form a second overlapping area. The present invention can reduce chip size and save hardware costs.

Description

Electronic device with two planar inductors

technical field

The embodiments disclosed in the present invention relate to an electronic device, especially an electronic device having a first planar inductor and a second planar inductor partially overlapping each other.

Background technique

Inductors are common passive components in circuit systems that can be used for filtering, blocking current, storing energy, and more. For example, an inductor is used to store energy in a DC-DC converter, and the amount of stored energy is proportional to the value of the inductor. In order to meet the needs of the system, the required value of the inductor is usually larger. For another example, two inductors can be coupled to each other to form a transformer.

However, the area occupied by the inductor in the integrated circuit is much larger than that of other components. Therefore, it is necessary to find a new structure of the inductor to reduce the area required for the implementation of the inductor, that is, to increase the unit area of the inductor. The inductance value contributed by the area.

Contents of the invention

According to an embodiment of the present invention, an electronic device having a first planar inductor and a second planar inductor partially overlapping each other is disclosed to solve the above problems.

According to a first embodiment of the present invention, an electronic device is disclosed, including a first planar inductor and a second planar inductor. Wherein the first planar inductor at least includes a first ring structure and a second ring structure connected to generate a first magnetic field with a first direction and a second magnetic field with a second direction respectively. A magnetic field, wherein the first direction is different from the second direction. The second planar inductor at least includes a third ring structure and a fourth ring structure connected to generate a third magnetic field with a third direction and a fourth magnetic field with a fourth direction, respectively. A magnetic field, wherein the third direction is different from the fourth direction. Wherein the first annular structure overlaps at least a part of the third annular structure to form a first overlapping region, and at least a part of the second annular structure overlaps with the fourth annular structure to form a second overlapping area.

One of the advantages of the present invention is that it can reduce the chip area required for implementing the inductor, that is, increase the inductance value contributed by the unit area of the inductor element, thereby reducing the hardware cost.

Description of drawings

FIG. 1 is a schematic diagram of a first embodiment of the electronic device of the present invention.

FIG. 2A is a schematic diagram of a second embodiment of the electronic device of the present invention.

FIG. 2B is a schematic diagram of a third embodiment of the electronic device of the present invention.

FIG. 2C is a schematic diagram of a fourth embodiment of the electronic device of the present invention.

FIG. 2D is a schematic diagram of a fifth embodiment of the electronic device of the present invention.

FIG. 3A is a schematic diagram of a sixth embodiment of the electronic device of the present invention.

FIG. 3B is a schematic diagram of a seventh embodiment of the electronic device of the present invention.

FIG. 4 is a frequency response diagram of coupling coefficient values of electronic devices composed of asymmetrical planar inductors with different overlapping area sizes.

FIG. 5 is a schematic diagram of an eighth embodiment of the electronic device of the present invention.

Fig. 6 is a frequency response diagram of inductance values of 8-shaped and non-8-shaped planar inductors.

Among them, the reference signs are explained as follows:

102, 104, 202A, 204A, 202B, 204B, 202C,

204C, 202D, 204D, 302A, 304A, 302B, 304B planar inductors

106, 206A, 206B, 206C, 206D, 306A, 306B, 500 Electronics

1022, 1024, 1042, 1044, 2022A, 2024A,

2042A, 2044A, 2022B, 2024B, 2042B, 2044B ring configuration

502, 504 some components

Detailed ways

FIG. 1 is a schematic diagram of a first embodiment of the electronic device of the present invention. One of the electronic devices 106 is an inductor formed by a planar inductor 102 and a planar inductor 104 . The planar inductor 102 is located on a first conductor layer, and includes a first ring structure 1022 and a second ring structure 1024 to generate a first magnetic field with a first direction and a first magnetic field with a second direction respectively. Two magnetic fields, for example, the first direction is perpendicular to a plane formed by the first annular structure 1022 and goes upward from the bottom of the plane; and the second direction is perpendicular to a plane formed by the second annular structure 1024 And from the top of the plane down. The planar inductor 102 has an inductance H ₁₀₂ . On the other hand, the planar inductor 104 is located on a second conductor layer different from a first conductor layer, and includes a first ring structure 1042 and a second ring structure 1044 and respectively generates a ring structure with a third direction. The third magnetic field and a fourth magnetic field with a fourth direction, for example, the third direction is perpendicular to a plane formed by the first annular structure 1042 and is upward from the bottom of the plane; and the fourth direction is vertical A plane formed by the second ring structure 1044 and downwards from above the plane. Wherein the first direction is the same as the third direction, and the second direction is the same as the fourth direction. Wherein, the opening of the first annular structure 1022 faces to the right of the drawing, the opening of the second annular structure 1024 faces upward of the drawing, the opening of the third annular structure 1042 faces to the right of the drawing, and the fourth annular structure The opening of 1044 faces downward in the drawing. The planar inductor 104 has an inductance H ₁₀₄ . In the present invention, the planar inductor 102 and the planar inductor 104 are coupled and stacked to form an electronic device (inductor) 106 . Wherein, the terminal of the first ring structure 1022 and the terminal of the third ring structure 1042 can be connected through a via (VIA) so that the planar inductor 102 and the planar inductor 104 together form an inductor (ie, the electronic device 106 ). The plane area formed by the first ring structure 1022 and the second ring structure 1024 of the planar inductor 102 and the plane area formed by the first ring structure 1042 and the second ring structure 1044 of the planar inductor 104 completely overlap, To increase an inductance H ₁₀₆ of the electronic device (inductor) 106 as much as possible. The inductance value H ₁₀₆ is made larger than the inductance value H ₁₀₂ and the inductance value H ₁₀₄ respectively, so as to increase the inductance value per unit area. Specifically, the structure obtained by combining two 8-like planar inductors by winding wires in this way can achieve a larger inductance value per unit area than the known spiral structure. In addition, since the magnetic field directions of the first ring structure 1022 and the third ring structure 1042 are opposite to those of the second ring structure 1024 and the fourth ring structure 1044 , electromagnetic interference (EMI) can be reduced.

FIG. 2A is a schematic diagram of a second embodiment of the electronic device of the present invention. One of the electronic devices 206A is a transformer formed by a planar inductor 202A and a planar inductor 204A. The planar inductor 202A is located on a first conductor layer, and includes a first ring structure 2022A and a second ring structure 2024A and generates a first magnetic field and a second magnetic field in different directions, for example, the direction of the first magnetic field is perpendicular to a plane formed by the first annular structure 2022A and goes upward from the bottom of the plane; and the second magnetic field direction is perpendicular to a plane formed by the second annular structure 2024A and goes upward from the top of the plane. Down. The planar inductor 202A has an inductance H _202A . On the other hand, the planar inductor 204A is located in a second conductor layer different from the first conductor layer, and includes a first ring structure 2042A and a second ring structure 2044A and generates a first magnetic field in different directions respectively. and a second magnetic field, for example, the first magnetic field direction is perpendicular to a plane formed by the first annular structure 2042A and goes upward from the bottom of the plane; and the second magnetic field direction is perpendicular to the second annular structure 2044A A plane is formed and goes down from above the plane. The planar inductor 204A has an inductance H204A. In the present invention, the planar inductor 202A and the planar inductor 204A are stacked to form an electronic device (transformer) 206A. The first annular structure 2022A and the second annular structure 2024A of the planar inductor 202A with the coupling coefficient value K _206A form the planar area and the first annular structure 2042A and the second annular structure 2044A of the planar inductor 204A The size of the overlapping area between the formed planar areas is determined. In practice, the first annular structure 2022A and the second annular structure 2024A are not limited to be implemented on the same die. In some embodiments, 3D stack packaging can be used, that is, the first ring structure 2022A and the second ring structure 2024A can be respectively located on the upper die and the lower die (or the opposite design). , and the middle is filled with a dielectric (under-fill) material. Other embodiments may also have similar designs.

FIG. 2B is a schematic diagram of a third embodiment of the electronic device of the present invention. One of the electronic devices 206B is a transformer formed by a planar inductor 202B and a planar inductor 204B. The planar inductor 202B includes a first ring structure 2022B located on a first conductor layer and a second ring structure 2024B located on a second conductor layer, and generates a first magnetic field with a first direction and a second ring structure 2024B respectively. There is a second magnetic field in a second direction, for example, the first direction is perpendicular to a plane formed by the first annular structure 2022B and goes upward from the bottom of the plane; and the second direction is perpendicular to the second annular structure Construction 2024B forms a plane and descends from above the plane. The planar inductor 202B has an inductance H202B. On the other hand, the planar inductor 204B includes a first ring structure 2042B located on the second conductor layer and a second ring structure 2044B located on the first conductor layer, and respectively generate a ring structure with a third direction. The third magnetic field and a fourth magnetic field with a fourth direction, for example, the first direction is perpendicular to a plane formed by the first annular structure 2042B and goes upward from the bottom of the plane; and the second direction is vertical A plane is formed on the second ring structure 2044B and goes down from above the plane. The planar inductor 204B has an inductance H204B. In the present invention, the planar inductor 202B and the planar inductor 204B are stacked to form an electronic device (transformer) 206B, wherein the first annular structure 2022B of the planar inductor 202B overlaps with the first annular structure 2042B of the planar inductor 204B; The second annular structure 2024B of the planar inductor 202B overlaps with the second annular structure 2044B of the planar inductor 204B, so although the planar inductor 202B and the planar inductor 204B both use two layers of conductor layers, the combined electronic device ( Transformer) 206B still requires only two conductor layers in total. Wherein the size of the coupling coefficient value K _206B is formed by the planar area formed by the first ring structure 2022B and the second ring structure 2024B of the planar inductor 202B and the first ring structure 2042B and the second ring structure of the planar inductor 204B The size of the overlapping area between the plane areas formed by 2044B is determined.

FIG. 2C is a schematic diagram of a fourth embodiment of the electronic device of the present invention. One of the electronic devices 206C is a transformer formed by a planar inductor 202C and a planar inductor 204C. The electronic device 206C is similar to the electronic device 206A, the only difference is that a coupling coefficient value K _206C of the electronic device 206C is larger than a coupling coefficient value K _206A of the electronic device 206A due to the larger overlapping area. In addition, the electronic device 206C uses one more conductor layer for winding than the electronic device 206A.

FIG. 2D is a schematic diagram of a fifth embodiment of the electronic device of the present invention. One of the electronic devices 206D is a transformer formed by a planar inductor 202D and a planar inductor 204D. The electronic device 206D is similar to the electronic device 206B, the only difference is that a coupling coefficient value K206D of the electronic device 206D is greater than a coupling coefficient value K206B of the electronic device 206B due to the larger overlapping area. In addition, the electronic device 206D uses one more conductor layer for winding than the electronic device 206B.

FIG. 3A is a schematic diagram of a sixth embodiment of the electronic device of the present invention. One of the electronic devices 306A is a transformer formed by an asymmetric planar inductor 302A and an asymmetric planar inductor 304A. The electronic device 306A is similar to the electronic device 206A, the only difference being that the number of rings of a first ring structure and a second ring structure of the planar inductor 302A in the electronic device 306A are different, so that the first ring structure of the planar inductor 302A The magnitudes of the magnetic fields of the ring structure and the second ring structure are different; the same is true for the planar inductor 304A. Specifically, the first ring structure with more loops in the planar inductor 302A in the electronic device 306A partially overlaps the first loop structure with more loops in the planar inductor 304A; and The second ring structure with a smaller number of rings in the planar inductor 302A in the electronic device 306A partially overlaps the second ring structure with a smaller number of rings in the planar inductor 304A.

FIG. 3B is a schematic diagram of a seventh embodiment of the electronic device of the present invention. One of the electronic devices 306B is a transformer formed by an asymmetric planar inductor 302B and a mirrored asymmetric planar inductor 304B. The electronic device 306B is similar to the electronic device 306A, and the only difference is that a first ring structure with a larger number of rings in the planar inductor 302B in the electronic device 306B partially overlaps with a first ring structure with a smaller number of rings in the planar inductor 304B. A first ring structure; and a second ring structure with a smaller number of ring turns in the planar inductor 302B in the electronic device 306B partially overlaps a second ring with a larger number of ring turns in the planar inductor 304B shaped structure. In this way, due to the anti-phase cancellation effect caused by the asymmetric mirror structure, plus the displacement between the planar inductor 302B and the planar inductor 304B is larger than the displacement between the planar inductor 302A and the planar inductor 304A is larger, according to Ampere's right-hand rule (thumbrule), at this time the anti-phase cancellation effect is intensified. Therefore, the coupling coefficient value K 306B of the electronic device (transformer) _306B is lower than that of the electronic device (transformer) 306A.

FIG. 4 is a frequency response diagram of coupling coefficient values of electronic devices composed of asymmetrical planar inductors with different overlapping area sizes. One of the curves C1 represents an asymmetric planar inductor (8-shaped planar inductor structure with 2 coils: 1 coil) and another asymmetric planar inductor (8-shaped planar inductor structure with 2 coils) : 1 circle) The frequency response of the coupling coefficient value of an electronic device (transformer) (similar to the configuration in Fig. 3A) stacked on each other, wherein the overlapping of the asymmetric planar inductor and the other asymmetric planar inductor The degree is the maximum (completely overlapping or almost completely overlapping); a curve C2 represents an asymmetric planar inductor (8-shaped planar inductor structure and the number of coils is 2 turns: 1 turn) and another mirror image asymmetric planar inductor The frequency response of the coupling coefficient value of an electronic device (transformer) (similar to the configuration in Figure 3B) formed by stacking each other (figure 8 planar inductor structure and the number of coils is 1 turn: 2 turns), wherein the asymmetrical plane The degree of overlap between the planar inductor and the other asymmetrical planar inductor is maximum (complete overlap or almost complete overlap). From the curves C1 and C2, it can be seen that at low frequencies (about 13GHz or less), at the degree of complete overlap or almost complete overlap, using an asymmetric planar inductor to stack another mirrored asymmetric planar inductor can substantially reduce the Coupling value, so when the target coupling value is low, the same low coupling value effect can be achieved with a smaller area. In addition, with the configuration of curve C1, the degree of overlap is reduced to 75% and 50%, respectively, and a curve C3 and a curve C5 can be obtained; with the configuration of curve C2, the degree of overlap is respectively reduced to 75% and 50%, and it can be obtained A curve C4 and a curve C6. From the curves C3, C4, C5, and C6 in Figure 4, it can be seen that at low frequencies (below about 10GHz), in the case of overlapping degrees of 75% and 50%, an asymmetrical planar inductor is used to stack another mirror image The asymmetrical planar inductor can substantially and significantly reduce the coupling value, so when the target coupling value is low, the purpose of placing two inductors or a transformer at the same time can be achieved with a smaller area. Therefore, different overlapping degrees or areas can be used to design and achieve desired coupling coefficient values.

FIG. 5 is a schematic diagram of an eighth embodiment of the electronic device of the present invention. An electronic device 500 is an 8-shaped planar inductor, including a part of elements 502 located on a first conductor layer and another part of elements 504 located on a second conductor layer. The part of the elements 502 and the part of the elements 504 have two overlapping portions, namely a first intersection point P1 and a second intersection point P2. Fig. 6 is a frequency response diagram of inductance values of 8-shaped and non-8-shaped planar inductors. In Fig. 6, a curve D1 is the inductance value corresponding to different frequencies of the 8-shaped planar inductance in Fig. 5; a curve D2 is the inductance value of the non-8-shaped planar inductance corresponding to different frequencies, which is the same as the 8-shaped inductance in Fig. 5 Font planar inductors have the same area. It can be seen from FIG. 6 that the electronic device 500 in FIG. 5 effectively increases the inductance value (I) per unit area within a certain frequency range to achieve the purpose of reducing chip size and saving hardware costs.

It should be noted that the actual shape of the ring structure of the planar inductor in the present invention is not limited to the specific shape of the ring structure of the planar inductor in the embodiment. That is, the loop structure of the planar inductor can be square, circular or polygonal. In addition, the loop structure of the planar inductor or the arrangement of its windings in different conductor layers is not limited to the above-mentioned embodiments.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims (9)

1. An electronic device comprising: A first planar inductor at least includes a first ring structure and a second ring structure connected to generate a first magnetic field with a first direction and a second magnetic field with a second direction respectively. a magnetic field, wherein the first direction is in a different direction than the second direction; and A second planar inductor at least includes a third ring-shaped structure and a fourth ring-shaped structure connected to generate a third magnetic field with a third direction and a first magnetic field with a fourth direction, respectively. Four magnetic fields, wherein the third direction is different from the fourth direction; Wherein the first annular structure overlaps at least a part of the third annular structure to form a first overlapping region, and at least a part of the second annular structure overlaps with the fourth annular structure to form a second overlapping area; Wherein the first planar inductor and the second planar inductor form a transformer; Wherein the transformer has a coupling coefficient value, and the value of the coupling coefficient is determined by the size of the first and second overlapping regions; Wherein, the first planar inductor and the second planar inductor are similar to figure-eight planar inductors. 2. The electronic device as claimed in claim 1, wherein the first planar inductor has a first inductance value, the second planar inductor has a second inductance value, and the first planar inductor is coupled to the first planar inductor. Two planar inductors to form a third inductor with a third inductance value, the third inductance value is greater than any one of the first inductance value and the second inductance value, and the size of the third inductance value is determined according to The size of the first and second overlapping regions is determined. 3. The electronic device as claimed in claim 1, wherein the first direction is the same as the third direction, and the second direction is the same as the fourth direction. 4. The electronic device as claimed in claim 1, wherein the first planar inductor is located on a first conductor layer, and the second planar inductor is located on a second conductor layer. 5. The electronic device as claimed in claim 1, wherein the first ring structure and the second ring structure are respectively located on a first conductor layer and a second conductor layer, the third ring structure and the fourth The ring structures are respectively located on the second conductor layer and the first conductor layer. 6. The electronic device as claimed in claim 1, wherein at least a part of the first ring-shaped structure overlaps with the fourth ring-shaped structure to form a third overlapping region. 7. The electronic device as claimed in claim 6, wherein the first magnetic field is larger than the second magnetic field, and the third magnetic field is smaller than the fourth magnetic field. 8. The electronic device as claimed in claim 1, wherein the opening direction of the first ring structure is the same as that of the third ring structure, and the opening direction of the second ring structure is different from that of the fourth ring structure. 9 . The electronic device as claimed in claim 1 , wherein the first planar inductor and the second planar inductor are located in different dies, and form a transformer together using a three-dimensional stack structure.