Inductively-coupled mems resonators

Patent metadata

Field	Value
Publication number	US-2020212881-A1
Application number	US-201816235382-A
Country	US
Kind code	A1
Filing date	Dec 28, 2018
Priority date	Dec 28, 2018
Publication date	Jul 2, 2020
Grant date	—

Abstract

An apparatus includes a microelectromechanical system (MEMS) die having a first surface and an opposing second surface. The MEMS die includes a surface-mounted resonator on the first surface and includes a first inductor. The apparatus also includes first and second dies. The first die has a third surface and an opposing fourth surface. The first die is coupled to the MEMS die such that the third surface of the first die faces the first surface of the MEMS die. The first and second surfaces are spaced apart. The first die includes an oscillator circuit and a second inductor. The oscillator circuit is coupled to the second inductor. The second inductor is inductively coupled to the first inductor. The second die is electrically coupled to the first die.

First claim

What is claimed is:

1 . An apparatus, comprising:
a microelectromechanical system (MEMS) die having a first surface and an opposing second surface, the MEMS die including a surface-mounted resonator on the first surface and including a first inductor; a first die having a third surface and an opposing fourth surface, the first die coupled to the MEMS die such that the third surface of the first die faces the first surface of the MEMS die, the first and second surfaces being spaced apart, the first die including an oscillator circuit and a second inductor, the oscillator circuit coupled to the second inductor, and the second inductor adapted to be inductively coupled to the first inductor; and a second die electrically coupled to the first die.

2 . The apparatus of claim 1 , further comprising a mold compound encapsulating the MEMS and the first and second dies.

3 . The apparatus of claim 1 , further comprising a material on the second surface of the MEMS die, the material between the second surface and the mold compound, and the material having a Young's Modulus less than 100 MPa.

4 . The apparatus of claim 1 , wherein the MEMS die includes a cavity in the first surface, and the surface-mounted resonator extends over at least a portion of the cavity.

5 . The apparatus of claim 1 , wherein the MEMS die includes a cavity in the first surface defined by an outer edge thereof, and the outer edge of the first surface is adhered to the third surface of the first die.

6 . The apparatus of claim 1 , further comprising an encapsulation frame disposed between the first die and the MEMS die, the encapsulation frame defining an interior area, wherein the first inductor, the second inductor and the surface-mounted resonator reside within the interior area.

7 . The apparatus of claim 1 , further comprising an encapsulation frame disposed between the first die and the MEMS die, the encapsulation frame defining an interior area, and the surface-mounted resonator residing within the interior area.

8 . The apparatus of claim 7 , wherein the encapsulation frame comprises a passivation material.

9 . The apparatus of claim 1 , wherein a surface area of the first die is larger than a surface area of the MEMS die, and the third surface includes a bond pad to which a bond wire is adhered.

10 . The apparatus of claim 1 , wherein a surface area of the first die is the same as a surface area of the MEMS die, and the first die includes a through-silicon-via (TSV) between the third and fourth surfaces to provide an electrical connection between the second die and the oscillator circuit.

11 . The apparatus of claim 1 , wherein the second die is adhered to the fourth surface of the first die.

12 . The apparatus of claim 1 , further comprising solder bumps coupling the third surface of the first die to the second die, wherein the MEMS die is between the third surface and the second die.

13 . An apparatus, comprising:
a microelectromechanical system (MEMS) die having a first surface and an opposing second surface, the MEMS die including a surface-mounted resonator on the first surface and including a first inductor; a first die having a third surface and an opposing fourth surface, the first die coupled to the MEMS die such that the third surface of the first die faces the first surface of the MEMS die, the first and second surfaces being spaced apart, the first die including an oscillator circuit and a second inductor, the oscillator circuit coupled to the second inductor, and the second inductor adapted to be inductively coupled to the first inductor; and a mold compound encapsulating the MEMS die and the first die.

14 . The apparatus of claim 13 , wherein the MEMS die includes a cavity in the first surface, and the surface-mounted resonator covers at least a portion of the cavity.

15 . The apparatus of claim 13 , wherein the MEMS die includes a cavity in the first surface defined by an outer edge thereof, the outer edge of the first surface is adhered to the third surface of the first die.

16 . The apparatus of claim 13 , further comprising an encapsulation frame disposed between the first die and the MEMS die, the encapsulation frame defining an interior area, and the first and second inductors residing within the interior area.

17 . The apparatus of claim 13 , wherein a surface area of the first die is larger than a surface area of the MEMS die, and the third surface includes a bond pad to which a bond wire is adhered.

18 . The apparatus of claim 13 , wherein a surface area of the first die is the same as a surface area of the MEMS die, and the first die includes a through-silicon-via (TSV) between the third and fourth surfaces.

19 . The apparatus of claim 13 , further including a second die also encapsulated by the mold compound, and wherein the second die is adhered to the fourth surface of the first die.

20 . The apparatus of claim 13 , further including:
a second die encapsulated by the mold compound; and solder bumps coupling the third surface of the first die to the second die, wherein the MEMS die is between the third surface and the second die.

Assignees

• Texas Instruments Inc

Inventors

• Bahr Bichoy
• Yen Ting-Ta

Classifications

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W74/142

  the encapsulations exposing the passive side of the semiconductor body · CPC title

• H10W90/28

  the stacked chips having different sizes, e.g. chip stacks having a pyramidal shape · CPC title

• H10W90/756

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W72/536

  the connected ends being ball-shaped · CPC title