CN112103048A - TSV-based nested transformer - Google Patents

Abstract

The invention discloses a nested transformer based on TSV, comprising a base body, a primary winding and a secondary winding are arranged in the base body, the primary winding is embedded inside the secondary winding, the primary winding has a port a and a port, and the secondary winding has a port c and port d, port b and port c are ground terminals, port a and port d are the input and output terminals of the transformer, respectively, the primary winding and the secondary winding are composed of TSVs and metal wires connected to TSVs . In the TSV-based nested transformer of the present invention, the primary winding and the metal of the secondary winding are adjacent to each other, so that the primary winding and the secondary winding in the transformer can achieve good coupling, and the through-silicon hole and the metal wire connecting the through-silicon hole can be passed through. The primary winding and the secondary winding are formed, which greatly reduces the volume of the transformer and improves the integration.

Description

A Nested Transformer Based on TSV

technical field

The invention belongs to the technical field of passive electronic devices, and relates to a nested transformer based on TSV.

Background technique

As an important passive device, transformers are widely used to achieve impedance matching, low noise feedback, differential to single-ended conversion, and input differential mode inductor pairing. The traditional chip transformer is a plane or a laminated structure, and faces the problem of occupying a large chip area. With the development of three-dimensional integrated circuits in recent years, through-hole technology has also received more and more attention. In three-dimensional integrated circuits, in addition to realizing vertical interconnections between chips, through silicon vias are also used to fabricate integrated passive devices, and three-dimensional transformers are one of its applications.

Compared with the traditional chip transformer, the three-dimensional transformer has a smaller chip footprint, which improves the integration and effectively solves the problems faced by the traditional chip transformer. However, there are still many immature places in the existing three-dimensional transformer technology. For example, the primary coil (or called the primary winding) and the secondary coil (or called the secondary coil) in the existing three-dimensional transformer cannot achieve good coupling, resulting in The three-dimensional transformer is prone to failure during the working process, which seriously affects its application.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a nested transformer based on TSV, which solves the problem of poor coupling performance between the primary coil and the secondary coil in the existing three-dimensional transformer.

The technical solution adopted by the present invention is that a TSV-based nested transformer includes a base body, a primary winding and a secondary winding are arranged in the base body, the primary winding is embedded inside the secondary winding, and the primary winding has a port a and a port, The secondary winding has port c and port d, port b and port c are both ground terminals, port a and port d are the input and output terminals of the transformer, respectively, the primary winding and the secondary winding are connected by silicon through holes and through silicon through holes. Hole composed of metal wires.

The technical feature of the present invention is also that,

The base consists of a top dielectric layer, an intermediate silicon substrate layer and a bottom dielectric layer.

Disconnected first-layer metal lines and second-layer metal lines are respectively arranged inside the top dielectric layer from top to bottom, and disconnected third-layer metal lines and fourth-layer metal lines are respectively arranged inside the bottom dielectric layer from top to bottom Lines, the inside of the silicon substrate layer is sequentially provided with a first row of through silicon vias, a second row of through silicon vias, a third row of through silicon vias and a fourth row of through silicon vias.

The primary winding consists of the second column of TSVs, the third column of TSVs, the second layer of metal wires and the third layer of metal wires, and the tops of the second row of TSVs and the third row of TSVs are alternated by the second layer of metal wires Connection, the bottom is alternately connected through the third layer of metal lines.

The number of TSVs in the second row and the third row of TSVs is the same, which is N1, and N1 corresponds to the number of turns of the primary winding.

The secondary winding consists of the first column of TSVs, the fourth column of TSVs, the first layer of metal wires and the fourth layer of metal wires, and the tops of the first column of TSVs and the fourth row of TSVs pass through the first layer of metal The wires are alternately connected, and the bottoms are alternately connected by the fourth layer of metal wires.

The number of TSVs in the first row and the fourth row of TSVs is the same, which is N2, and N2 corresponds to the number of turns of the secondary winding.

Port d is drawn from one end of the metal wire of the first layer, port a is drawn from one end of the metal wire of the second layer, port b is drawn from one end of the metal wire of the third layer, and port c is drawn from the end of the metal wire of the fourth layer one end of the lead out.

Port a and port d are located on opposite sides of the base, respectively.

TSVs consist of inner metal pillars and an outer insulating layer, and metal lines communicate with the inner metal pillars.

The beneficial effect of the invention is that the primary winding is embedded inside the secondary winding, and the primary winding is adjacent to the metal of the secondary winding, so that the primary winding and the secondary winding in the transformer can achieve good coupling; the two windings in the transformer can achieve good coupling; The resistance only needs to occupy the area of one winding, which reduces the footprint of the transformer; the primary winding and the secondary winding are composed of the through-silicon via and the metal wire connecting the through-silicon hole, which greatly reduces the volume of the transformer and improves the performance of the transformer. Integration; by arranging the input end and the output end of the transformer on opposite sides of the transformer, it is convenient to connect the transformer with the external circuit, and the port coupling capacitance can be reduced, and the resonant frequency can be increased; the present invention adopts multiple metal layers and The nested structure can be adapted to the existing integrated circuit technology, and the number of turns of the primary winding and the secondary winding can be changed by changing N1 and N2, that is, transformers with different transformation ratios can be realized.

Description of drawings

1 is a schematic diagram of the overall structure of a TSV-based nested transformer of the present invention;

FIG. 2 is a schematic diagram of the internal structure of a TSV-based nested transformer of the present invention.

In the figure, 1. top dielectric layer, 2. middle silicon substrate layer, 3. bottom dielectric layer, 4. first metal wire, 5. second metal wire, 6. third metal wire, 7. fourth Layer metal lines, 8. TSVs in the first row, 9. TSVs in the second row, 10. TSVs in the third row, 11. Port a, 12. Port b, 13. TSVs in the fourth row, 21. Port c, 22. Port d.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

A nested transformer based on TSV of the present invention, referring to FIG. 1 and FIG. 2, includes a base body, a primary winding and a secondary winding are arranged in the base body, the primary winding is embedded in the secondary winding to form a nested structure, and the primary winding Adjacent to the secondary winding, the distance between the primary winding and the adjacent through-silicon vias of the secondary winding is 20 microns, and the distance between the adjacent metal wires of the two windings is 10 microns, so that the primary and secondary windings in the transformer can be Good coupling is achieved; two windings only need to occupy the area of one winding, reducing the footprint of the transformer.

The primary winding has port a11 and port b12, the secondary winding has port c21 and port d22, both port b12 and port c21 are ground terminals, port a11 and port d22 are the input and output of the transformer respectively, the primary winding and the secondary winding Both consist of through-silicon vias and metal lines connecting the through-silicon vias.

The base consists of a top dielectric layer 1 , an intermediate silicon substrate layer 2 and a bottom dielectric layer 3 . The top dielectric layer 1 is provided with disconnected first-layer metal lines 4 and second-layer metal lines 5 from top to bottom, and the bottom dielectric layer 3 is provided with disconnected third-layer metal lines 6 from top to bottom. and the fourth layer of metal lines 7 , the silicon substrate layer 2 is provided with a first row of TSVs 8 , a second row of TSVs 9 , a third row of TSVs 10 and a fourth row of TSVs 13 , which are arranged side by side in sequence.

The primary winding consists of the second row of TSVs 9, the third row of TSVs 10, the second layer of metal wires 5 and the third row of metal wires 6, and the tops of the second row of TSVs 9 and the third row of TSVs 10 pass through The second-layer metal wires 5 are alternately connected, and the bottoms are alternately connected through the third-layer metal wires 6 . That is, the metal wire 5 of the second layer is first connected to the first TSV of the second row of TSVs 9, and then to the first TSV of the third row of TSVs 10, and then to the second row of TSVs. Hole 9 is connected to the second through silicon via, and so on.

The secondary winding consists of the first column of TSVs 8, the fourth row of TSVs 13, the first layer of metal wires 4 and the fourth layer of metal wires 7, the first row of TSVs 8 and the fourth row of TSVs 13 The tops are alternately connected by the first layer of metal wires 4 , and the bottoms are alternately connected by the fourth layer of metal wires 7 .

The number of TSVs in the second row of TSVs 9 and the third row of TSVs 10 is the same, which is N1, and the number of TSVs in the first row of TSVs 8 and the fourth row of TSVs 13 is the same. For N2, by changing N1 and N2, transformers with different transformation ratios can be manufactured.

In this embodiment, N1 and N2 are both 3, and each row of TSVs in the first row of TSVs 8 , the second row of TSVs 9 , the third row of TSVs 10 and the fourth row of TSVs 13 One by one relative.

The port d22 is drawn from the front end of the metal wire 4 of the first layer, the port a11 is drawn from the rear end of the metal wire 5 of the second layer, the port b12 is drawn from the rear end of the metal wire 6 of the third layer, and the port c21 is drawn from the fourth layer. The front end of the metal wire 7 is drawn out, and the port a11 and the port d22 are respectively located on opposite sides of the transformer, which is convenient for connecting the transformer to the external circuit, and can reduce the port coupling capacitance and increase the resonant frequency.

The TSV is composed of an inner metal column and an outer insulating layer, which is made by the TSV process, and the metal wire is connected with the inner metal column. The inner metal column can be selected from copper or aluminum, and copper is selected in this embodiment; the outer insulating layer, the top dielectric layer 1 and the bottom dielectric layer 3 can be selected from silicon dioxide, silicon nitride or silicon oxynitride, and two are selected in this embodiment. Silicon oxide. The first layer of metal wires 4, the second layer of metal wires 5, the third layer of metal wires 6 and the fourth layer of metal wires 7 are all made by the redistribution layer RDL technology, and the material is copper or aluminum. In this embodiment, copper is selected. .

Claims (10)

1. The nested transformer based on the TSV is characterized by comprising a base body, wherein a primary winding and a secondary winding are arranged in the base body, the primary winding is embedded in the secondary winding, the primary winding is provided with a port a (11) and a port b (12), the secondary winding is provided with a port c (21) and a port d (22), the port b (12) and the port c (21) are both grounded ends, the port a (11) and the port d (22) are respectively an input end and an output end of the transformer, and the primary winding and the secondary winding are both composed of through silicon vias and metal wires connected with the through silicon vias.

2. A TSV-based nested transformer according to claim 1, characterized in that the base body consists of a top dielectric layer (1), an intermediate silicon substrate layer (2) and a bottom dielectric layer (3).

3. The TSV-based nested transformer of claim 2, wherein the top dielectric layer (1) is internally provided with a first layer of metal wires (4) and a second layer of metal wires (5) which are not connected from top to bottom, the bottom dielectric layer (3) is internally provided with a third layer of metal wires (6) and a fourth layer of metal wires (7) which are not connected from top to bottom, and the silicon substrate layer (2) is internally provided with a first row of through silicon vias (8), a second row of through silicon vias (9), a third row of through silicon vias (10) and a fourth row of through silicon vias (13) which are arranged side by side in sequence.

4. A nested TSV-based transformer according to claim 3, wherein the primary winding is composed of a second row of through silicon vias (9), a third row of through silicon vias (10), a second layer of metal lines (5) and a third layer of metal lines (6), the second row of through silicon vias (9) and the third row of through silicon vias (10) are alternately connected at the top by the second layer of metal lines (5) and at the bottom by the third layer of metal lines (6).

5. A nested TSV-based transformer according to claim 4, wherein the number of through silicon vias in the second and third columns of through silicon vias (9, 10) is the same.

6. A nested TSV-based transformer according to claim 5, wherein the secondary winding is composed of a first column of through silicon vias (8), a fourth column of through silicon vias (13), a first layer of metal lines (4) and a fourth layer of metal lines (7), wherein the top of the first column of through silicon vias (8) and the top of the fourth column of through silicon vias (13) are alternately connected through the first layer of metal lines (4), and the bottom of the first column of through silicon vias is alternately connected through the fourth layer of metal lines (7).

7. A nested TSV-based transformer according to claim 6, wherein the number of through silicon vias in the first column of through silicon vias (8) and the number of through silicon vias in the fourth column of through silicon vias (13) are the same.

8. A nested TSV-based transformer according to claim 7, wherein the port d (22) is led out from one end of the first layer metal wire (4), the port a (11) is led out from one end of the second layer metal wire (5), the port b (12) is led out from one end of the third layer metal wire (6), and the port c (21) is led out from one end of the fourth layer metal wire (7).

9. A nested TSV based transformer according to claim 8 wherein the ports a (11) and d (22) are located on opposite sides of the substrate.

10. The TSV-based nested transformer of claim 1, wherein the through silicon vias are comprised of inner metal posts and outer insulating layers, the metal lines communicating with the inner metal posts.

Images