DISTRIBUTED LC FILTER STRUCTURE

• US 20200136221A1
• Filed: 12/27/2019
• Published: 04/30/2020
• Est. Priority Date: 06/30/2017
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Voiron, Frederic, Jatlaoui, Mohamed Mehdi
• Granted Patent: US 10,903,538 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 2223/6627 Waveguides, e.g. microstrip line, strip line, coplanar line
• CPC Class Codes: H01L 23/66 High-frequency adaptations
• CPC Class Codes: H01L 27/016 Thin-film circuits
• CPC Class Codes: H01L 28/10 Inductors
• CPC Class Codes: H01L 28/90 having vertical extensions
• CPC Class Codes: H01P 1/20 Frequency-selective devices, e.g. filters
• CPC Class Codes: H02M 1/44 Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
• CPC Class Codes: H03H 7/0123 comprising distributed impedance elements together with lumped impedance elements

Abstract

A distributed LC filter structure is disclosed. The distributed LC filter structure provides simultaneously a distributed inductance and a distributed capacitance in the same structure. Accordingly, discrete passive elements are eliminated and high, homogenous integration is achieved. Interconnections between the distributed inductance and the distributed capacitance are tailored to leverage a parasitic inductance of the distributed capacitance to increase the overall inductance of the distributed LC filter structure. Similarly, the interconnections are tailored to leverage a parasitic capacitance resulting from the distributed inductance to add up with the distributed capacitance augmenting the overall capacitance of the structure.

Claims

1. A distributed LC filter structure, comprising:

a substrate having a trench etched in a top surface thereof;

a first conductive layer disposed in the trench;

a first insulator-metal structure disposed in the trench on top of the first conductive layer, with the first insulator-metal structure comprising a first insulator layer disposed on the first conductive layer and a second conductive layer disposed on the first insulator layer;

a second insulator-metal structure disposed in the trench on top of the first insulator-metal structure, with the second insulator-metal structure comprising a second insulator layer disposed on the second conductive layer and a third conductive layer disposed on the second insulator layer;

a first insulation layer disposed along the top surface of the substrate above the third conductive layer;

a first metal layer disposed on the first insulation layer;

a second insulation layer disposed on the first metal layer;

a second metal layer disposed on the second insulation layer;

a first contact array connecting the first conductive layer to the first metal layer;

a second contact array connecting the second conductive layer to the second metal layer; and

a third contact array connecting the third conductive layer to the first metal layer.

2. The distributed LC filter structure of claim 1, wherein the first conductive layer, the second conductive layer, and the third conductive layer provide first, second, and third electrodes, respectively, that form a first capacitive cell of the distributed LC filter.

3. The distributed LC filter structure of claim 2, wherein the first, second, and third electrodes form a second capacitive cell of the distributed LC filter that is coupled in parallel with the first capacitive cell.

4. The distributed LC filter structure of claim 3, wherein in at least one of the first and second capacitive cells, the first and second electrodes form a first capacitance and the second and third electrodes form a second capacitance, the first capacitance being in parallel with the second capacitance.

5. The distributed LC filter structure of claim 3, wherein the second metal layer provides an inductance of the distributed LC filter structure.

6. The distributed LC filter structure of claim 5, wherein at least one of the first contact array, the second contact array, and the third contact array is configured such that a parasitic inductance of at least one of the first and second capacitive cells is coupled in series with the inductance provided by the second metal layer.

7. The distributed LC filter structure of claim 5, wherein the first and second capacitive cells underlie an entire length of the second metal layer, thereby forming a uniformly distributed LC structure.

8. The distributed LC filter structure of claim 5, wherein the first and second capacitive cells underlie only a portion of a length of the second metal layer.

9. The distributed LC filter structure of claim 8, wherein the distributed LC filter structure includes one of a L+LC, a LC+L, or a L+LC+L filter.

10. The distributed LC filter structure of claim 1, wherein the second metal layer has a length and a width, with the length being larger than the width by a factor of at least 100.

11. The distributed LC filter structure of claim 1, wherein the first metal layer is connected to a ground terminal and the second metal layer is connected to an input signal terminal.

12. The distributed LC filter structure of claim 1, wherein the first contact array, the second contact array, and the third contact array each have an equal contact density with respect to each other.

13. The distributed LC filter structure of claim 1, wherein the first contact array, the second contact array, and the third contact array each have an equal pitch with respect to each other.

14. The distributed LC filter structure of claim 1, wherein the distributed LC filter structure is coupled to a Power Management Integrated Circuit (PMIC) flip-chip bonded onto the substrate.

15. A DC-DC converter comprising a distributed LC filter structure according to claim 1.

16. A distributed LC filter structure, comprising:

a substrate having a trench extending therein;

a first conductive layer disposed in the trench;

a first insulator layer disposed in the trench and on the first conductive layer;

a second conductive layer disposed in the trench and on the first insulator layer;

a second insulator layer disposed in the trench and on the second conductive layer;

a third conductive layer disposed in the trench and on the second insulator layer;

a first insulation layer disposed along a top surface of the substrate and above the third conductive layer;

a first metal layer disposed on the first insulation layer;

a second insulation layer disposed on the first metal layer;

a second metal layer disposed on the second insulation layer; and

a plurality of contact arrays connecting the first, second and third conductive layers to the first, second and third metal layers, respectively.

17. The distributed LC filter structure of claim 16, wherein the first, second and third conductive layers provide a plurality of electrodes that form a first capacitive cell of the distributed LC filter.

18. The distributed LC filter structure of claim 17, wherein the plurality of electrodes form a second capacitive cell of the distributed LC filter that is coupled in parallel with the first capacitive cell.

19. The distributed LC filter structure of claim 18,

wherein the second metal layer provides an inductance of the distributed LC filter structure;

and

wherein at least one of the plurality of contact arrays is configured such that a parasitic inductance of at least one of the first and second capacitive cells is coupled in series with the inductance provided by the second metal layer.

20. The distributed LC filter structure of claim 18,

wherein the second metal layer provides an inductance of the distributed LC filter structure,

wherein the first and second capacitive cells underlie only a portion of a length of the second metal layer, and

wherein the distributed LC filter structure includes one of a L+LC, a LC+L, or a L+LC+L filter.