Microelectromechanical systems using thermocompression bonding

• US 7,276,789 B1
• Filed: 05/20/2004
• Issued: 10/02/2007
• Est. Priority Date: 10/12/1999
• Status: Expired due to Fees

• Current Assignee: Microassembly Technologies Incorporated
• Original Assignee: Microassembly Technologies Incorporated
• Inventors: Cohn, Michael B., Kung, Joseph T.
• Primary Examiner(s): Coleman; W. David
• Application Number:
  US10/851,751
• Time in Patent Office: 1,230 Days
• Field of Search: 257/704, 257/E23.183, 257/E23.125
• US Class Current: 257/704
• CPC Class Codes: B81C 1/00238 Joining a substrate with an electronic processing unit and a substrate with a micromechanical structure
• CPC Class Codes: B81C 2203/0109 Bonding an individual cap on the substrate
• CPC Class Codes: B81C 2203/0118 Bonding a wafer on the substrate, i.e. where the cap consists of another wafer
• CPC Class Codes: B81C 2203/019 characterised by the material or arrangement of seals between parts
• CPC Class Codes: H01L 2224/05553 being rectangular
• CPC Class Codes: H01L 2224/13111 Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48095 Kinked
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 2224/75 Apparatus for connecting with bump connectors or layer connectors
• CPC Class Codes: H01L 2224/7598 specially adapted for batch processes
• CPC Class Codes: H01L 2224/81801 Soldering or alloying
• CPC Class Codes: H01L 2224/85207 Thermosonic bonding
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 24/75 Apparatus for connecting with bump connectors or layer connectors
• CPC Class Codes: H01L 24/81 using a bump connector
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01032 : Germanium [Ge]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01045 : Rhodium [Rh]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01075 : Rhenium [Re]
• CPC Class Codes: H01L 2924/01077 : Iridium [Ir]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/1461 : MEMS
• CPC Class Codes: H01L 2924/15788 : Glasses, e.g. amorphous oxides, nitrides or fluorides
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/207 : Diameter ranges
• CPC Class Codes: H01L 2924/30105 : Capacitance
• CPC Class Codes: H01L 2924/3011 : Impedance

Abstract

Improved microelectromechanical systems (MEMS), processes and apparatus using thermocompression bonding are disclosed. For example, process embodiments are disclosed in which wafer-scale as well as die-scale thermocompression bonding is utilized to encapsulate MEMS and/or to provide electrical interconnections with MEMS. Apparatus embodiments include apparatus for performing thermocompression bonding and bonded hybrid structures manufactured in accordance with the process embodiments. Devices having various substrate bonding and/or sealing configurations variously offer the advantage of reduced size, higher manufacturing yields, reduced costs, improved reliability, improved compatibility with existing semiconductor manufacturing process and/or greater versatility of applications.

Claims

1. A bonded hybrid structure, comprising:

a first substrate;

a sensing device disposed on the first substrate and having at least one electrical terminal comprising a bump of conductive bonding material;

a second substrate;

an integrated circuit disposed on the second substrate, and having at least one terminal comprising a bump of conductive bonding material;

a dielectric substrate in aligned confronting relation to the first and second substrates;

plural target features of conductive bonding material disposed on the dielectric substrate, at least partially congruent with the bumps of the first and second substrates;

the first and second substrates being bonded to the dielectric substrate such that the plural bumps are bonded and electrically coupled to respective ones of the target features; and

plural conductive lines disposed on the dielectric substrate and extending from the target features bonded to the bumps of the first substrate to respective ones of the target features bonded to the bumps of the second substrate to thereby electrically couple the sensing to the integrated circuit.

2. The bonded hybrid structure of claim 1, wherein at least one of the plural target features of conductive bonding material has a minimum height of about 2 microns.

3. The bonded hybrid structure of claim 2, wherein at least one of the plural target features of conductive bonding material has a minimum height of about 2 microns after bonding.

4. The bonded hybrid structure of claim 1, wherein said bonded hybrid structure comprises a device selected from the list of:

RF MEMS, RF MEMS switch, RF MEMS phase shifter, RF MEMS mixer, RF MEMS filter, micromirrors, accelerometer, gyroscope, pressure sensor, tunable capacitor, resonator, acoustic wave device, micro-relay, and inertial sensor.

5. The bonded hybrid structure of claim 1,

wherein said bonded hybrid structure comprises one of an RF MEMS switch and a micro-relay;

wherein said sensing device on said first substrate contains at least one mechanical component of said bonded hybrid structure, and

wherein said second substrate contains at least one portion of an electrical circuit of said bonded hybrid structure.

6. The bonded hybrid structure of claim 1 wherein

the first substrate comprises a silicon-on-insulator substrate.

7. The bonded hybrid structure of claim 1 wherein

the sensing device comprises a high aspect silicon-on-insulator structure.

8. The bonded hybrid structure of claim 1 wherein

the sensing device comprises at least one silicon layer.

9. A sensor comprising:

a first substrate;

a microelectromechanical device disposed on the first substrate and having at least one electrical terminal comprising one or more bumps of conductive bonding material;

a second substrate which is in aligned confronting relation to the first substrate;

an integrated circuit disposed on the second substrate, the integrated circuit having at least one terminal;

one or more target features of conductive bonding material disposed on the second substrate, the target features being at least partially congruent and in electrical contact with the bumps of the first substrate;

the first and second substrates being bonded together in aligned confronting relation such that the bumps are bonded to respective ones of the target features to thereby electrically couple the microelectromechanical device and the integrated circuit.

10. The sensor of claim 9 wherein

the microelectromechanical device is an inertial sensor comprising a mass flexurally suspended from the first substrate and having terminals capacitively coupled to the mass such that the capacitance between the terminals and the mass varies as the mass is displaced;

and

the integrated circuit is a capacitive readout circuit, the first and second substrates being bonded such that the respective bumps and target features electrically couple the inertial sensor and the capacitive readout circuit.

11. The sensor of claim 10 wherein

the integrated circuit further comprises a voltage amplifier;

the first and second substrates are bonded such that the respective bumps and target features electrically couple the inertial sensor and the voltage amplifier.

12. The sensor of claim 9 further comprising:

bonding material on the first substrate that forms a first ring and bonding material on the second substrate that forms a second ring, bonds between the first and second rings being thermocompressive bonds wherein least one of the first and second rings has been plastically deformed, and wherein bonds between respective bumps and target features are thermocompressive bonds, at least one of the bumps and target features being plastically deformed.

13. The sensor of claim 9 wherein

the first substrate comprises a silicon-on-insulator substrate.

14. The sensor of claim 9 wherein

the microelectromechanical device comprises a high aspect silicon-on-insulator structure.

15. The sensor of claim 9 wherein

the microelectromechanical device comprises at least one silicon layer.

16. A sensor comprising:

a first substrate;

a sensing device disposed on the first substrate and having electrical terminals comprising bumps of conductive bonding material;

a dielectric substrate which is in aligned confronting relation to the first substrate;

plural wire-bond pads disposed on the dielectric substrate;

plural target features of conductive bonding material disposed on the dielectric substrate, the target features being at least partially congruent and in electrical contact with the bumps of the first substrate; and

plural conductive lines disposed on the dielectric substrate and extending from respective target features to the wire-bond pads;

the first substrate and the dielectric substrate being thermocompressively bonded together such that plural bumps are bonded to respective ones of the target features to thereby form electrical connections having low-parasitic capacitance from the sensor to the wire-bond pads.

17. The sensor of claim 16 further comprising

a second substrate;

and

an integrated circuit disposed on the second substrate and having electrical terminals comprising wire-bonds pads;

wherein the wire-bond pads of the dielectric substrate are electrically coupled to the wire-bond pads of the second substrate such that the sensing device is electrically coupled to the integrated circuit.

18. The sensor of claim 16 wherein

the sensor is an inertial sensor comprising a mass flexurally suspended from the first substrate and having terminals capacitively coupled to the mass such that the capacitance between the terminals and the mass varies as the mass is displaced;

and

the integrated circuit is a capacitive readout circuit.

19. The sensor of claim 16 wherein

the dielectric substrate is at least substantially transparent;

and

the sensing device is a diode detector.

20. The sensor of claim 16 wherein

the first substrate comprises a silicon-on-insulator substrate.

21. The sensor of claim 16 wherein

the sensing device comprises a high aspect silicon-on-insulator structure.

22. The sensor of claim 16 wherein

the sensing device comprises at least one silicon layer.

23. A sensor comprising:

a first substrate;

a sensing device disposed on the first substrate and having electrical terminals comprising bumps of conductive bonding material;

a first dielectric substrate which is in aligned confronting relation to the first substrate;

plural wire-bond pads disposed on the first dielectric substrate;

plural target features of conductive bonding material disposed on the dielectric substrate, the target features being at least partially congruent and electrically coupled with the bumps of the first substrate;

plural conductive lines disposed on the first dielectric substrate and extending from respective target features to the wire-bond pads of the first dielectric substrate;

the first substrate and the first dielectric substrate being bonded together such that plural bumps are bonded to respective ones of the target features to thereby form electrical connections from the sensor to the wire-bond pads;

a second substrate;

an integrated circuit disposed on the second substrate and having electrical terminals comprising bumps of conductive bonding material;

a second dielectric substrate which is in aligned confronting relation to the second substrate;

plural wire-bond pads disposed on the second dielectric substrate;

plural target features of conductive bonding material disposed on the second dielectric substrate, the target features being at least partially congruent and electrically coupled with the bumps of the second substrate; and

plural conductive lines disposed on the second dielectric substrate and extending from respective target features to the wire-bond pads of the second dielectric substrate;

the second substrate and the second dielectric substrate being bonded together such that the plural bumps are bonded to respective ones of the target features to thereby form electrical connections from the integrated circuit to the wire-bond pads; and

wherein the wire-bond pads of the first dielectric substrate are electrically coupled to the wire-bond pads of the second dielectric substrate such that the sensing device is electrically coupled to the integrated circuit with extremely low parasitic capacitance.

24. The sensor of claim 23 wherein

the sensing device is an inertial sensor comprising a mass flexurally suspended from the first substrate and having terminals capacitively coupled to the mass such that the capacitance between the terminals and the mass varies as the mass is displaced;

and

the integrated circuit is a capacitive readout circuit.

25. The sensor of claim 23 wherein the integrated circuit further comprises a voltage amplifier.

26. The sensor of claim 23 wherein

the first dielectric substrate is at least substantially transparent;

and

the sensing device is a diode detector.

27. The sensor of claim 23 wherein

the first substrate comprises a silicon-on-insulator substrate.

28. The sensor of claim 23 wherein

the sensing device comprises a high aspect silicon-on-insulator structure.

29. The sensor of claim 23 wherein

the sensing device comprises at least one silicon layer.