MICROELECTRONIC PACKAGES HAVING HERMETIC CAVITIES AND METHODS FOR THE PRODUCTION THEREOF

• US 20160167952A1
• Filed: 03/31/2014
• Published: 06/16/2016
• Est. Priority Date: 03/31/2014
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Philip H. Bowles, Stephen R. Hooper
• Inventors: BOWLES, PHILIP H., HOOPER, STEPHEN R.
• Granted Patent: US 10,442,685 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2201/0242 Gyroscopes
• CPC Class Codes: B81B 7/0041 maintaining a controlled atmosphere with techniques not provided for in B81B7/0038
• CPC Class Codes: B81B 7/02 containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS] B81B7/04 takes precedence
• CPC Class Codes: B81C 1/0023 Packaging together an electronic processing unit die and a micromechanical structure die MEMS packages B81B7/0032; MEMS packaging processes B81C1/00261
• CPC Class Codes: B81C 1/00293 maintaining a controlled atmosphere with processes not provided for in B81C1/00285
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 Encapsulation

Abstract

Microelectronic packages having hermetic cavities are provided, as are methods for producing such packages. In one embodiment, the microelectronic package includes a sensor die having first and second Microelectromechanical Systems (MEMS) transducer structures formed thereon. First and second cap pieces are coupled to the sensor die by, for example, direct or indirect bonding. A first hermetic cavity encloses the first MEMS transducer structure and is at least partially defined by the first cap piece and the sensor die. Similarly, a second hermetic cavity encloses the second MEMS transducer structure and at least partially defined by the second cap piece and the sensor die. A vent hole is fluidly coupled to the first hermetic cavity and is sealed by the second cap piece.

Claims

1. A microelectronic package, comprising:

a sensor die having first and second Microelectromechanical Systems (MEMS) transducer structures formed thereon;

first and second cap pieces coupled to the sensor die;

a first hermetic cavity enclosing the first MEMS transducer structure and at least partially defined by the first cap piece and the sensor die;

a second hermetic cavity enclosing the second MEMS transducer structure and at least partially defined by the second cap piece and the sensor die; and

a vent hole fluidly coupled to the first hermetic cavity and sealed by the second cap piece.

2. The microelectronic package of claim 1 further comprising an Application Specific Integrated Circuit formed on at least one of the first cap piece and the second cap piece.

3. The microelectronic package of claim 1 wherein the first and second MEMS transducer structures comprise a MEMS accelerometer structure and a MEMS gyroscope structure, respectively.

4. The microelectronic package of claim 1 wherein the first and second MEMS transducer structures are formed on a frontside of the sensor die in a side-by-side relationship.

5. The microelectronic package of claim 4 further comprising bonding material attaching the first cap to the sensor die and providing a vertical standoff therebetween, a portion of the bonding material disposed between and partitioning the first and second hermetic cavities.

6. The microelectronic package of claim 1 wherein the vent hole is formed through the first cap piece, and wherein the second cap piece is bonded to the first cap piece opposite the sensor die.

7. The microelectronic package of claim 1 wherein the vent hole is formed through the sensor die, and wherein the first and second cap pieces are bonded to opposing surfaces of the sensor die.

8. The microelectronic package of claim 1 further comprising:

a recess etched into one of the first cap piece, the second cap piece, and the sensor die; and

a microelectronic component housed within the recess.

9. The microelectronic package of claim 8 wherein the microelectronic component comprises a magnetometer die.

10. The microelectronic package of claim 8 wherein the recess is fluidly coupled to the second hermetically-sealed cavity.

11. A microelectronic package, comprising:

a sensor die having a frontside surface;

a first Microelectromechanical Systems (MEMS) transducer structure formed on the frontside surface;

a first cap piece bonded to frontside surface of the sensor die and extending over the first MEMS transducer structure;

a first hermetic cavity enclosing the first MEMS transducer structure and defined, at least in part, by the sensor die and the first cap piece;

a recess formed in at least one of the sensor die and the first cap piece, the recess in fluid communication with the first hermetic cavity; and

a microelectronic component housed within the recess.

12. The microelectronic package of claim 11 wherein the microelectronic component comprises a magnetometer die.

13. The microelectronic component of claim 11 further comprising a vent hole formed in one of the sensor die and the first cap piece, the recess in fluid communication with the vent hole.

14. The microelectronic package of claim 13 further comprising a second cap piece coupled to the sensor die, bonded to the first cap piece so as to seal the vent hole, and having the microelectronic component mounted thereto.

15. The microelectronic package of claim 11 further comprising an Application Specific Integrated Circuit formed on the first cap piece.

16. A method for fabricating a microelectronic package including first and second Microelectromechanical Systems (MEMS) transducer structures formed on a sensor die and enclosed within first and second cavities, respectively, the method comprising:

bonding a first cap piece to the sensor die to seal the first cavity at a first predetermined pressure;

venting the second cavity to a surrounding pressure through a vent hole during or after bonding the first cap piece to the sensor die; and

sealing the second cavity at a second predetermined pressure different than the first predetermined pressure by covering the vent hole with a second cap piece bonded to one of the first cap piece and the sensor die.

17. The method of claim 16 wherein the first cap piece, the second cap piece, and the sensor die are bonded while in wafer form.

18. The method of claim 16 further comprising mounting a microelectronic component to the second cap piece such that the microelectronic component is received within a recess formed in one of the first cap piece and the sensor die when the second cap piece is positioned so as to sealingly enclose the vent hole.

19. The method of claim 16 wherein venting comprises venting the second cavity to a surrounding pressure through a vent hole formed in the first cap piece, and wherein sealing the second cavity comprises bonding the second cap piece to the first cap piece opposite the sensor die.

20. The method of claim 16 wherein venting comprises venting the second cavity to a surrounding pressure through a vent hole formed in the sensor die, and wherein sealing the second cavity comprises bonding the second cap piece to the sensor die opposite the first cap piece.