Microelectromechanical device packages with integral heaters

• US 7,449,773 B2
• Filed: 01/25/2005
• Issued: 11/11/2008
• Est. Priority Date: 05/22/2003
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Tarn, Terry
• Primary Examiner(s): LOUIE, WAI SING
• Application Number:
  US11/043,539
• Publication Number:
  US 20050185248A1
• Time in Patent Office: 1,386 Days
• Field of Search: 257/680, 257/682, 257/434, 257/778, 257/772, 257/779, 257/780, 257/686, 257/690, 257/700, 257/704
• US Class Current: 257/700
• CPC Class Codes: B81C 1/00269 Bonding of solid lids or wafers to the substrate
• CPC Class Codes: B81C 2203/0181 Using microheaters for bonding the lid
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• 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 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12044 OLED
• CPC Class Codes: H01L 2924/16195 Flat cap [not enclosing an internal cavity]
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor

Abstract

A microelectromechanical device package with integral a heater and a method for packaging the microelectromechanical device are disclosed in this invention. The microelectromechanical device package comprises a first package substrate and second substrate, between which a microelectromechanical device, such as a micromirror array device is located. In order to bonding the first and second package substrates so as to package the microelectromechanical device inside, a sealing medium layer is deposited, and heated by the heater so as to bond the first and second package substrates together.

Claims

1. A device package comprising:

a first ceramic substrate that comprises a concaved surface forming a cavity in the first ceramic substrate;

a second ceramic substrate layer comprising an opening, the second ceramic substrate layer being laminated to the first ceramic substrate with a heater and a bonding material therebetween;

wherein the opening in the second ceramic substrate layer is aligned to the cavity in the first ceramic substrate; and

the heater is disposed around a periphery of the cavity between the first ceramic substrate and the second ceramic substrate layer;

a microelectromechanical device disposed in the cavity;

a light transmissive substrate disposed on a surface of the second ceramic substrate layer and enclosing the microelectromechanical device within the cavity; and

a sealing medium disposed between the second ceramic substrate layer and the light transmissive substrate, wherein the heater is in thermal connection with the sealing medium through the bonding material and the second ceramic substrate layer, such that the heater is capable of melting the sealing medium.

2. The package of claim 1, wherein the light transmissive substrate is glass.

3. The package of claim 1, wherein the light transmissive substrate is quartz.

4. The package of claim 1, wherein the microelectromechanical device is a micromirror array device.

5. The package of claim 4, wherein the micromirror array device comprises a semiconductor substrate having formed thereon an array of deflectable reflective mirror plates;

and wherein the semiconductor substrate is bonded to the first ceramic substrate.

6. The package of claim 4, wherein the micromirror array device comprises a semiconductor substrate and a light transmissive device substrate having formed therebetween an array of deflectable reflective mirror plates;

and wherein the semiconductor substrate is bonded to the first ceramic substrate.

7. The package of claim 4, wherein the sealing medium comprises a hermetic bond between the second ceramic substrate layer and the light transmissive substrate.

8. The package of claim 4, wherein the sealing medium comprises a non-hermetic bond between the second ceramic substrate layer and the light transmissive substrate.

9. The package of claim 4, wherein the sealing medium is a solder material.

10. The package of claim 9, wherein the solder material is Au, BiSn_x, AuSn_x, InAg_x or PbSn_x.

11. The package of claim 10, wherein the solder material is BiSn_x.

12. The package of claim 10, wherein the solder material is InAg_x.

13. The package of claim 9, further comprising:

a first metallization layer for metalizing a top surface of the second ceramic substrate layer adjacent the sealing medium.

14. The package of claim 9, further comprising:

a second metallization layer for metalizing a bottom surface of the light transmissive substrate adjacent the sealing medium.

15. The package of claim 1, wherein the heater is laminated between the first ceramic substrate and the second ceramic substrate layer without extending into the cavity.

16. The package of claim 1, wherein the light transmissive substrate comprises a light blocking frame supporting an inlay glass window overlying the microelectromechanical device.

17. A device package comprising:

a planar bottom ceramic substrate having a top surface;

a laminate comprising a plurality of ceramic substrate layers bonded together and to the planar bottom ceramic substrate and defining a cavity above the top surface of the planar bottom ceramic substrate;

a heater disposed on a top ceramic substrate layer of the plurality of ceramic substrate layers and around a periphery of the cavity;

an additional ceramic substrate layer having an opening, the additional ceramic substrate layer being bonded to the top ceramic substrate layer with a bonding material, and covering the heater such that the opening of the additional ceramic substrate layer is aligned to the cavity and the heater is embedded within an area between the additional ceramic substrate layer and the top ceramic substrate layer;

a microelectronic device disposed on the top surface of the planar bottom ceramic substrate;

a light transmissive substrate disposed on a top surface of the additional ceramic substrate layer and enclosing the microelectronic device within the cavity; and

a sealing medium disposed between the additional ceramic substrate layer and the light transmissive substrate, wherein the heater is in thermal connection with the sealing medium through the bonding material and the additional ceramic substrate layer, such that the heater is capable of melting the sealing medium.

18. The package of claim 17, wherein the light transmissive substrate comprises a light blocking frame supporting an inlay glass window overlying the microelectronic device.

19. The package of claim 17, wherein the light transmissive substrate is glass.

20. The package of claim 17, wherein the light transmissive substrate is quartz.

21. The package of claim 17, wherein the microelectronic device is a micromirror array device.

22. The package of claim 21, wherein the micromirror array device comprises a semiconductor substrate having formed thereon an array of deflectable reflective mirror plates;

and wherein the semiconductor substrate is bonded to the planar bottom ceramic substrate.

23. The package of claim 21, wherein the micromirror array device comprises a semiconductor substrate and a light transmissive device substrate having formed therebetween an array of deflectable reflective mirror plates;

and wherein the semiconductor substrate is bonded to the planar bottom ceramic substrate.

24. The package of claim 21, wherein the sealing medium comprises a hermetic bond between the additional ceramic substrate layer and the light transmissive substrate.

25. The package of claim 21, wherein the sealing medium comprises a non-hermetic bond between the additional ceramic substrate layer and the light transmissive substrate.

26. The package of claim 21, wherein the sealing medium is a solder material.

27. The package of claim 26, wherein the solder material is Au, BiSn_x, AuSn_x, InAg_x or PbSn_x.

28. The package of claim 27, wherein the solder material is BiSn_x.

29. The package of claim 27, wherein the solder material is InAg_x.

30. The package of claim 26, further comprising:

a first metallization layer for metalizing the top surface of the additional ceramic substrate layer adjacent the sealing medium.

31. The package of claim 26, further comprising:

a second metallization layer for metalizing a bottom surface of the light transmissive substrate adjacent the sealing medium.

32. The package of claim 17, wherein the heater is laminated between the first ceramic substrate and the second ceramic substrate layer without extending into the cavity.

33. A device package comprising:

a first planar ceramic substrate having a top surface;

a second planar ceramic substrate having a bottom surface bonded to the top surface of the first planar ceramic substrate;

a heater laminated with a bonding material between the first and second planar ceramic substrates and along a periphery of the first and second planar ceramic substrates;

a ceramic substrate layer bonded to a top surface of the second planar ceramic substrate;

the ceramic substrate layer overlying the heater and having an opening defining a cavity above the top surface of the second planar ceramic substrate;

a microelectronic device disposed within the cavity on the top surface of the second planar ceramic substrate;

a light transmissive substrate disposed on a top surface of the ceramic substrate layer; and

a sealing medium disposed between the ceramic substrate layer and the light transmissive substrate, wherein the heater is in thermal connection with the sealing medium through the bonding material and the ceramic substrate layer, such that the heater is capable of melting the sealing medium.

34. The package of claim 33, wherein the light transmissive substrate comprises a light blocking frame supporting an inlay glass window overlying the microelectronic device.

35. The package of claim 33, wherein the light transmissive substrate is glass.

36. The package of claim 33, wherein the light transmissive substrate is quartz.

37. The package of claim 33, wherein the microelectronic device is a micromirror array device.

38. The package of claim 37, wherein the micromirror array device comprises a semiconductor substrate having formed thereon an array of deflectable reflective mirror plates;

and wherein the semiconductor substrate is bonded to the second planar ceramic substrate.

39. The package of claim 37, wherein the micromirror array device comprises a semiconductor substrate and a light transmissive device substrate having formed therebetween an array of deflectable reflective mirror plates;

and wherein the semiconductor substrate is bonded to the second planar ceramic substrate.

40. The package of claim 37, wherein the sealing medium comprises a hermetic bond between the ceramic substrate layer and the light transmissive substrate.

41. The package of claim 37, wherein the sealing medium comprises a non-hermetic bond between the ceramic substrate layer and the light transmissive substrate.

42. The package of claim 37, wherein the sealing medium is a solder material.

43. The package of claim 42, wherein the solder material is Au, BiSn_x, AuSn_x, InAg_x or PbSn_x.

44. The package of claim 43, wherein the solder material is BiSn_x.

45. The package of claim 43, wherein the solder material is InAg_x.

46. The package of claim 42, further comprising:

a first metallization layer for metalizing the top surface of the ceramic substrate layer adjacent the sealing medium.

47. The package of claim 42, further comprising:

a second metallization layer for metalizing a bottom surface of the light transmissive substrate adjacent the sealing medium.

48. The package of claim 33, wherein the heater does not extend into a footprint of the cavity.