Moisture-resistant electronic device package and methods of assembly

• US 20050057883A1
• Filed: 09/16/2003
• Published: 03/17/2005
• Est. Priority Date: 09/16/2003
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Cobbley, Chad A., Bolken, Todd O., Heppler, Steven W., Baerlocher, Cary J.
• Granted Patent: US 6,953,891 B2
• Time in Patent Office: Days
• US Class Current: 361/301.300
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: H01L 21/4803 Insulating or insulated parts, e.g. mountings, containers, diamond heatsinks H01L21/4846 takes precedence; printed circuit boards H05K1/00
• CPC Class Codes: H01L 21/481 Insulating layers on insulating parts, with or without metallisation
• CPC Class Codes: H01L 21/50 Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
• 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 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16235 the bump connector connecting to a via metallisation of the item
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• 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 2224/48228 the bond pad being disposed in a recess of the surface of the item
• CPC Class Codes: H01L 2224/484 Connecting portions
• CPC Class Codes: H01L 2224/48997 Reinforcing structures
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 23/055 the leads having a passage through the base H01L23/057 takes precedence
• 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 23/28 : Encapsulations, e.g. encapsulating layers, coatings, e.g. for protectionH01L23/552 takes precedence; insulating layers for contacts or interconnections H01L23/5329
• CPC Class Codes: H01L 23/48 : Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor
• CPC Class Codes: H01L 23/49861 : Lead-frames fixed on or encapsulated in insulating substrates H01L23/4985, H01L23/49805 take precedence
• 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 27/14618 : Containers
• CPC Class Codes: H01L 27/14683 : Processes or apparatus peculiar to the manufacture or treatment of these devices or parts thereof not peculiar thereto H01L21/00
• 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 2924/00011 : Not 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 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01087 : Francium [Fr]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12042 : LASER
• 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 2924/16195 : Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H01L 2924/181 : Encapsulation

Abstract

Various embodiments for moisture-resistant image sensor packaging structures and methods of assembly are disclosed. Image sensor packages of the present invention include an interposer, a housing structure formed on the interposer for surrounding an image sensor chip, and a transparent cover. The housing structure may cover substantially all of the interposer chip surface. In another embodiment, the housing structure also covers substantially all of the interposer edge surfaces. The housing structure may also cover substantially all of the interposer attachment surface. An image sensor chip is electrically connected to the interposer with sealed wire bond connections or with sealed flip-chip connections. The housing structure may include runners that enable simultaneous sealing of the interior of the image sensor package and of the transparent cover.

Claims

1. An electronic device package comprising:

a substrate having a first surface, an opposing second surface, and a plurality of edge surfaces extending between the first surface and the second surface around a perimeter of the substrate;

at least one contact pad on the first surface of the substrate;

at least one attachment pad on the second surface of the substrate;

at least one conductive element electrically connecting the at least one contact pad and the at least one attachment pad; and

a housing structure disposed on the substrate and comprising a plurality of raised sidewalls extending along the perimeter of the substrate defining a cavity in the housing structure, wherein the cavity faces away from the substrate, and the housing structure extends across a bottom surface of the cavity to cover substantially all of the first surface of the substrate and includes at least one aperture in the bottom surface of the cavity exposing the at least one contact pad through the housing structure.

2. The electronic device package of claim 1, wherein the housing structure covers the plurality of edge surfaces of the substrate.

3. The electronic device package of claim 2, further comprising at least one protrusion extending from at least one edge surface of the plurality of edge surfaces.

4. The electronic device package of claim 3, wherein the at least one protrusion comprises a tie bar extending perpendicularly from the at least one edge surface.

5. The electronic device package of claim 4, wherein the tie bar is connected to another substrate of another electronic device package.

6. The electronic device package of claim 1, wherein the housing structure covers substantially all of the second surface of the substrate and includes at least one aperture exposing the at least one attachment pad through the housing structure.

7. The electronic device package of claim 1, wherein the housing structure comprises one of a mold compound, an epoxy, and a photocurable polymer or resin.

8. The electronic device package of claim 1, wherein the at least one contact pad comprises a plurality of contact pads and the at least one aperture in the bottom surface of the cavity comprises a plurality of apertures, each aperture of the plurality of apertures exposing a single contact pad of the plurality of contact pads.

9. The electronic device package of claim 1, wherein the at least one contact pad comprises a plurality of contact pads and the at least one aperture in the bottom surface of the cavity comprises a plurality of apertures, each aperture of the plurality of apertures exposing at least two contact pads of the plurality of contact pads.

10. The electronic device package of claim 1, further comprising an electronic device sensitive to light or other radiation mounted within the cavity of the housing structure and having at least one bond pad.

11. The electronic device package of claim 10, further comprising at least one bond wire electrically connecting the at least one bond pad to the at least one contact pad.

12. The electronic device package of claim 11, wherein the at least one bond wire is bonded directly to the at least one contact pad within the at least one aperture.

13. The electronic device package of claim 12, further comprising a sealant material substantially filling the at least one aperture.

14. The electronic device package of claim 11, further comprising a conductive material filling the at least one aperture exposing the at least one contact pad to a level that is substantially even with the bottom surface of the cavity, and wherein the at least one wire bond is bonded to the conductive material.

15. The electronic device package of claim 14, further comprising a sealant material deposited over the conductive material.

16. The electronic device package of claim 10, further comprising a conductive material filling the at least one aperture exposing the at least one contact pad to a level that is substantially even with the bottom surface of the cavity, and wherein the at least one bond pad is attached to the conductive material in a flip-chip configuration.

17. The electronic device package of claim 16, further comprising a sealing material filling a gap between the electronic device and the bottom surface of the cavity.

18. The electronic device package of claim 10, further comprising a ledge formed in the plurality of raised sidewalls of the housing structure and surrounding the cavity.

19. The electronic device package of claim 18, further comprising at least one channel formed in at least one sidewall of the plurality of raised sidewalls and extending from the ledge to the bottom surface of the cavity.

20. The electronic device package of claim 19, further comprising a sealing well formed in the housing structure adjacent to a junction of the ledge and the at least one channel.

21. The electronic device package of claim 19, further comprising a transparent cover supported by the ledge and covering the cavity.

22. The electronic device package of claim 21, further comprising a sealant material adhesively bonding the transparent cover to the housing structure and covering the bottom surface of the cavity.

23. The electronic device package of claim 1, wherein the at least one attachment pad is electrically connected to a higher-level electronic assembly.

24. A method of forming an electronic device package comprising:

providing a substrate having a first surface, an opposing second surface, and a plurality of edge surfaces extending between the first surface and the second surface around a perimeter of the substrate;

forming at least one contact pad on the first surface of the substrate;

forming at least one attachment pad on the second surface of the substrate that is electrically connected to the at least one contact pad;

covering substantially all of the first surface of the substrate with at least one layer of material to form a housing structure including a cavity having sidewalls and a bottom surface formed from the at least one layer of material, wherein the cavity faces away from the substrate; and

leaving at least one aperture in the bottom surface of the cavity to expose the at least one contact pad through the layer of material.

25. The method of claim 24, further comprising forming the at least one layer of material from a mold compound.

26. The method of claim 25, wherein covering substantially all of the first surface of the substrate comprises at least partially curing the mold compound onto the first surface of the substrate within a molding tool.

27. The method of claim 25, wherein covering substantially all of the first surface of the substrate comprises:

at least partially curing the mold compound in a molding tool; and

attaching the at least partially cured mold compound to the first surface of the substrate with an adhesive material.

28. The method of claim 24, further comprising covering the plurality of edge surfaces of the substrate with the layer of material.

29. The method of claim 28, wherein covering the plurality of edge surfaces comprises:

forming a plurality of protrusions extending from the plurality of edge surfaces;

placing the substrate into a mold cavity such that at least some of the plurality of protrusions provide a space between the plurality of edge surfaces and an interior surface of the mold cavity;

filling the space between the plurality of edge surfaces and the interior surface of the mold cavity with a mold compound; and

at least partially curing the mold compound onto the edge surfaces of the substrate.

30. The method of claim 29, wherein forming a plurality of protrusions extending from the plurality of edge surfaces comprises forming at least one of the plurality of protrusions as a tie bar that connects the substrate to another substrate of another electronic device package.

31. The method of claim 24, wherein covering substantially all of the first surface of the substrate with the at least one layer of material comprises forming superimposed layers of an at least partially cured material onto the first surface of the substrate.

32. The method of claim 31, wherein forming superimposed layers of an at least partially cured material comprises:

dispensing a liquid or gel material onto the first surface of the substrate; and

at least partially curing the liquid or gel material.

33. The method of claim 31, wherein forming superimposed layers of an at least partially cured material comprises:

disposing a volume of photocurable liquid above the first surface of the substrate; and

selectively curing portions of the volume of photocurable liquid to form the superimposed layers of the at least partially cured material.

35. The method of claim 24, wherein forming at least one contact pad comprises forming a plurality of contact pads and wherein forming at least one aperture in the bottom surface of the cavity comprises forming a plurality of apertures, each aperture of the plurality of apertures exposing a single contact pad of the plurality of contact pads.

36. The method of claim 24, wherein forming at least one contact pad comprises forming a plurality of contact pads and wherein forming at least one aperture in the bottom surface of the cavity comprises forming a plurality of apertures, each aperture of the plurality of apertures exposing at least two contact pads of the plurality of contact pads.

37. The method of claim 24, further comprising mounting an electronic device sensitive to light or other radiation within the cavity.

38. The method of claim 37, further comprising electrically connecting at least one bond pad of the electronic device to the at least one contact pad with at least one wire bond.

39. The method of claim 38, further comprising directly attaching the at least one wire bond to the at least one contact pad within the at least one aperture.

40. The method of claim 39, further comprising substantially filling the at least one aperture with sealant material.

41. The method of claim 38, further comprising:

filling the at least one aperture with a conductive material to a level that is substantially even with the bottom surface of the cavity; and

attaching the at least one wire bond to the conductive material.

42. The method of claim 41, further comprising depositing a sealant material over the conductive material.

43. The method of claim 37, further comprising:

filling the at least one aperture with a conductive material to a level that is substantially even with the bottom surface of the cavity; and

attaching at least one bond pad of the electronic device directly to the conductive material.

44. The method of claim 43, further comprising, filling a gap between the electronic device and the bottom surface of the cavity with a sealant material.

45. The method of claim 37, further comprising:

forming a ledge surrounding the cavity in the at least one layer of material; and

covering the cavity with a transparent cover supported by the ledge.

46. The method of claim 45, further comprising:

applying a sealant material to simultaneously adhesively bond the transparent cover to the housing structure and cover the bottom surface of the cavity.

47. The method of claim 46, wherein applying the sealant material comprises injecting the sealant material into at least one runner surrounding the transparent cover and at least one runner extending from the ledge to the bottom of the cavity.

48. The method of claim 24, further comprising attaching the at least one attachment pad to a higher-level electronic assembly.

34. The method of 24, further comprising:

covering substantially all of the second surface of the substrate with the at least one layer of material; and

forming at least another aperture to expose the at least one attachment pad through the layer of material.