Bi-level microelectronic device package with an integral window

• US 6,674,159 B1
• Filed: 02/25/2002
• Issued: 01/06/2004
• Est. Priority Date: 05/16/2000
• Status: Expired due to Term

• Current Assignee: National Technology & Engineering Solutions Of Sandia LLC (Honeywell International Inc.)
• Original Assignee: Sandia National Laboratories (Government of the United States of America)
• Inventors: Peterson, Kenneth A., Watson, Robert D.
• Primary Examiner(s): Talbott, David L.
• Assistant Examiner(s): THAI, LUAN C
• Application Number:
  US10/082,961
• Time in Patent Office: 680 Days
• Field of Search: 257/680, 257/777-780, 257/737-738, 257/431-434, 257/693, 257/704, 257/682, 257/698
• US Class Current: 257/680
• CPC Class Codes: B81B 7/0067 for controlling the passage of optical signals through the package
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32145 the bodies being stacked
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49109 outside the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 2225/1058 Bump or bump-like electrical connections, e.g. balls, pillars, posts
• CPC Class Codes: H01L 23/053 the container being a hollow construction and having an insulating or insulated base as a mounting for the semiconductor body
• 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 25/105 the devices being of a type provided for in group H01L27/00
• CPC Class Codes: H01L 27/14618 : Containers
• CPC Class Codes: H01L 27/14636 : Interconnect structures
• 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 2924/00012 : 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 2924/00015 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed as prior art
• CPC Class Codes: H01L 2924/01004 : Beryllium [Be]
• CPC Class Codes: H01L 2924/01012 : Magnesium [Mg]
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/0102 : Calcium [Ca]
• CPC Class Codes: H01L 2924/01025 : Manganese [Mn]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• 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 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/04941 : TiN
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15153 : the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/15165 : Monolayer substrate
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/16195 : Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H01L 2924/16235 : Connecting to a semiconductor or solid-state bodies, i.e. cap-to-chip
• CPC Class Codes: H01L 2924/1627 : stacked type assemblies, e.g. stacked multi-cavities
• CPC Class Codes: H01L 2924/16788 : Glasses, e.g. amorphous oxides, nitrides or fluorides
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/207 : Diameter ranges
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H05K 1/02 : Details
• CPC Class Codes: H05K 1/181 : associated with surface mounted components

Abstract

A package with an integral window for housing a microelectronic device. The integral window is bonded directly to the package without having a separate layer of adhesive material disposed in-between the window and the package. The device can be a semiconductor chip, CCD chip, CMOS chip, VCSEL chip, laser diode, MEMS device, or IMEMS device. The multilayered package can be formed of a LTCC or HTCC cofired ceramic material, with the integral window being simultaneously joined to the package during LTCC or HTCC processing. The microelectronic device can be flip-chip bonded so that the light-sensitive side is optically accessible through the window. The package has at least two levels of circuits for making electrical interconnections to a pair of microelectronic devices. The result is a compact, low-profile package having an integral window that is hermetically sealed to the package prior to mounting and interconnecting the microelectronic device(s).

Claims

1. A package with an integral window for housing a microelectronic device, comprising a monolithic multilayered body with an integral window;

wherein the body comprises;

a first sub-stack comprising at least one layer of an electrically insulating multilayered material, a first aperture disposed through the first sub-stack, and a first electrical conductor disposed on the top surface of the first sub-stack;

a second sub-stack comprising at least one layer of the electrically insulating multilayered material, a second aperture disposed through the first sub-stack, and a second electrical conductor disposed on the top surface of the second sub-stack;

a third sub-stack comprising at least one layer of the electrically insulating multilayered material and a third aperture disposed through the third sub-stack; and

an integral window disposed across the first aperture;

wherein the second sub-stack is stacked on top of the first sub-stack, and the third sub-stack is stacked on top of the second sub-stack;

wherein the third aperture is wider than the second aperture;

wherein the second aperture is wider than the first aperture; and

wherein the integral window is bonded directly to the body without having a separate layer of adhesive material disposed in-between the window and the body.

2. The package of claim 1, wherein the window is bonded directly to a lip recessed inside of the body.

3. The package of claim 1, wherein the geometrical relationship between the window and the body comprises an encased joint geometry.

4. The package of claim 1, wherein the geometry of the outer edge of the window comprises a self-locking geometry selected from the group consisting of a tapered outer edge, a convex rounded outer edge, and a chevron-shaped double-tapered outer edge.

5. The package of claim 1, wherein the window is disposed on the bottom surface of the first sub-stack and extends laterally along the bottom surface of the first sub-stack a sufficient distance beyond the periphery of the first aperture to provide a sufficiently large overlapping area to provide a sufficiently high bond strength.

6. The package of claim 1, wherein the window substantially fills the aperture.

7. The package of claim 6, wherein the window is formed by casting a castable window material directly into the aperture.

8. The package of claim 7, wherein the castable window material comprises a molten glass that has solidified after casting or a transparent liquid polymer that has hardened after casting.

9. The package of claim 1, wherein the window comprises an optically transparent material selected from the group consisting of glass, sapphire, fused silica, clear plastic, and clear polymer.

10. The package of claim 1, wherein the window comprises a material selected from the group consisting of silicon, germanium, metal, metal alloy, lithium niobate and lithium tantalate.

11. The package of claim 1, wherein the window comprises a material selected from the group consisting of barium fluoride, calcium fluoride, lithium fluoride, magnesium fluoride, potassium fluoride, sodium chloride, zinc oxide, and zinc selenide.

12. The package of claim 1, wherein the window comprises an anti-reflection coating.

13. The package of claim 1, wherein the window comprises means for filtering selected wavelengths of light.

14. The package of claim 1, wherein the window further comprises a lens for optically transforming the light that passes through the window.

15. The package of claim 1, wherein the window further comprises an array of binary optic lenslets for optically transforming the light that passes through the window.

16. The package of claim 1, wherein the multilayered material comprises a low-temperature cofired ceramic material fired at a temperature from about 600 C. to about 1000 C.

17. The package of claim 1, wherein the multilayered material comprises a high-temperature cofired ceramic material fired at a temperature from about 1300 C. to about 1800 C.

18. The package of claim 1, wherein the multilayered material comprises a polymer-based printed wiring board material.

19. The package of claim 1, wherein at least one electrical conductor comprises a thick-film metallized trace.

20. The package of claim 1, wherein at least one electrical conductor comprises an electrical lead.

21. A package with an integral window for housing a microelectronic device, comprising:

a monolithic body, comprising a electrically insulating multilayered material;

the body having a bottom surface, an opposing top surface, a stepped aperture disposed through the body, and at least two interior ledges;

a first electrical conductor disposed on the first interior ledge;

a second electrical conductor disposed on the second interior ledge;

an integral window disposed across the aperture and bonded directly to the body without having a separate layer of adhesive material disposed in-between the window and the body; and

a first microelectronic device flip-chip interconnected to the first electrical conductor on the first interior ledge.

22. The package of claim 21, wherein the first microelectronic device comprises a chip selected from the group consisting of a semiconductor chip, a CCD chip, a CMOS chip, a VCSEL chip, a laser diode chip, a LED chip, a MEMS chip, and a IMEMS chip.

23. The package of claim 21, wherein the first microelectronic device comprises a light-sensitive side facing the window.

24. The package of claim 21, further comprising a polymer underfill encapsulating at least one of the flip-chip electrical interconnections.

25. The package of claim 21, further comprising a continuous ring seal disposed in-between the first microelectronic device and the body.

26. The package of claim 25, wherein the atmosphere in-between the window and the ring seal comprises a dry inert gas other than air, selected from the group consisting of argon, nitrogen, and helium, and combinations thereof.

27. The package of claim 21, further comprising a second microelectronic device, mounted back-to-back to the first microelectronic device.

28. The package of claim 27, wherein the second microelectronic device is wirebonded to the second electrical conductor.

29. The package of claim 28, wherein the wirebond and the pair of microelectronic devices are substantially encapsulated in a polymer-based encapsulant, except for any light-sensitive surfaces.

30. The package of claim 29, further comprising an opening in the polymer-based encapsulant for providing open access to the front side of the second microelectronic device.

31. The package of claim 30, wherein the opening in the polymer-based encapsulant is defined by a dam that encircles at least some of the front side of the second microelectronic device, which prevents any encapsulant from occluding the front side of the second microelectronic device during encapsulation of the wirebond.

32. The package of claim 28, wherein the body further comprises a third electrical conductor disposed on a third interior ledge, and further wherein the second microelectronic device has a wirebond interconnection to the third electrical conductor.

33. The package of claim 21, further comprising a wirebond interconnect made from the backside of the first microelectronic device to the second electrical conductor on the second interior ledge.

34. The package of claim 33, wherein the wirebond interconnect and the backside of the first microelectronic device are substantially encapsulated in a polymer-based encapsulant.

35. The package of claim 21, further comprising a cover lid attached to the top surface of the body for sealing the package.

36. The package of claim 35, wherein the cover lid is attached to the body with a material selected from the group consisting of a hermetic sealant and a polymer-based adhesive.

37. The package of claim 35, wherein the atmosphere inside the sealed package comprises a dry inert gas other than air, selected from the group consisting of argon, nitrogen, and helium, and combinations thereof.

38. The package of claim 21, further comprising a second microelectronic device flip-chip bonded to the second conductor on the second interior ledge.

39. A package with an integral window for housing a microelectronic device, comprising:

a monolithic body, comprising a electrically insulating multilayered material;

the body having a bottom surface, an opposing top surface, a stepped aperture disposed through the body, and at least two interior ledges;

a first electrical conductor disposed on the first interior ledge;

a second electrical conductor disposed on the second interior ledge;

an integral window disposed across the aperture and bonded directly to the body without having a separate layer of adhesive material disposed in-between the window and the body; and

a first microelectronic device flip-chip interconnected to the first electrical conductor on the first interior ledge; and

further comprising a cover lid attached to the top surface of the body for sealing the package;

wherein the cover lid is transparent.

40. A package with an integral window for housing a microelectronic device, comprising:

a monolithic body, comprising a electrically insulating multilayered material;

the body having a bottom surface, an opposing top surface, a steered aperture disposed through the body, and at least two interior ledges;

a first electrical conductor disposed on the first interior ledge;

a second electrical conductor disposed on the second interior ledge;

an integral window disposed across the aperture and bonded directly to the body without having a separate layer of adhesive material disposed in-between the window and the body; and

a first microelectronic device flip-chip interconnected to the first electrical conductor on the first interior ledge; and

further comprising a cover lid attached to the top surface of the body for sealing the package;

wherein the cover lid comprises a window.

41. A package with an integral window for housing a microelectronic device, comprising:

a monolithic body, comprising a electrically insulating multilayered material;

the body having a bottom surface, an opposing top surface, a stepped aperture disposed through the body, and at least two interior ledges;

a first electrical conductor disposed on the first interior ledge;

a second electrical conductor disposed on the second interior ledge;

an integral window disposed across the aperture and bonded directly to the body without having a separate layer of adhesive material disposed in-between the window and the body; and

a first microelectronic device flip-chip interconnected to the first electrical conductor on the first interior ledge;

wherein the first microelectronic device comprises a light-sensitive side facing the window;

wherein the package is mounted on, and is electrically interconnected to, a printed wiring board;

wherein the printed wiring board comprises an opening through the board; and

wherein the aperture in the package is aligned with the opening in the printed wiring board, thereby allowing light to pass through both the opening and the aperture to interact with the light-sensitive side of the first microelectronic device.