Flip-chip image sensor packages

• US 6,956,295 B2
• Filed: 07/03/2003
• Issued: 10/18/2005
• Est. Priority Date: 08/29/2002
• Status: Expired due to Fees

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Kinsman, Larry D.
• Primary Examiner(s): Flynn, Nathan J.
• Assistant Examiner(s): MANDALA, VICTOR A
• Application Number:
  US10/613,277
• Publication Number:
  US 20040056365A1
• Time in Patent Office: 838 Days
• Field of Search: 257/778, 257/779, 257/786, 257/737, 438/108, 438/613
• US Class Current: 257/786
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 27/14618 Containers
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/14634 Assemblies, i.e. Hybrid structures
• CPC Class Codes: H01L 27/14636 Interconnect structures
• 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 27/1469 Assemblies, i.e. hybrid integration
• 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 2924/15192 Resurf arrangement of the internal vias
• CPC Class Codes: H01L 31/02005 for device characterised by at least one potential jump barrier or surface barrier
• CPC Class Codes: H01L 31/0203 Containers; Encapsulations , e.g. encapsulation of photodiodesfor photovoltaic devices H01L31/048; for organic photosensitive devices H10K30/80

Abstract

The present invention provides flip-chip packaging for optically interactive devices such as image sensors and methods of assembly. In a first embodiment of the invention, conductive traces are formed directly on the second surface of a transparent substrate and an image sensor chip is bonded to the conductive traces. Discrete conductive elements are attached to the conductive traces and extend below a back surface of the image sensor chip. In a second embodiment, a secondary substrate having conductive traces formed thereon is secured to the transparent substrate. In a third embodiment, a backing cap having a full array of attachment pads is attached to the transparent substrate of the first embodiment or the secondary substrate of the second embodiment. In a fourth embodiment, the secondary substrate is a flex circuit having a mounting portion secured to the second surface of the transparent substrate and a backing portion bent over adjacent to the back surface of the image sensor chip.

Claims

1. An electronic device package comprising:

a transparent substrate;

a plurality of conductive traces positioned on a surface of the transparent substrate, each conductive trace of the plurality of conductive traces having a first attachment point and a second attachment point;

a plurality of optically interactive electronic devices, each optically interactive electronic device having at least one bond pad and mounted to the transparent substrate by a bond between the first attachment point of an associated conductive trace of the plurality of conductive traces and the at least one bond pad;

a plurality of backing caps, each backing cap covering a back surface of each optically interactive electronic device and having at least one backing cap attachment point on a surface thereof in electrical communication with the second attachment point of the associated conductive trace and at least one attachment pad on a another surface of the backing cap in electrical communication with the at least one backing cap attachment point.

2. The electronic device package according to claim 1, further comprising:

a bond between the at least one backing cap attachment point and the second attachment point of the associated conductive trace, the bond comprising one of a conductive or conductor-filled epoxy, a solder joint and a layer of anisotropically conductive adhesive material.

3. The electronic device package according to claim 1, further comprising:

an array of attachment pads on the another surface of the backing cap, the array of attachment pads positioned adjacent four edges of an outer perimeter of the another surface of the backing cap.

4. The electronic device package according to claim 1, further comprising:

a discrete conductive element disposed on the at least one attachment pad on the another surface of the backing cap.

5. The electronic device package according to claim 4, wherein the discrete conductive element comprises one of a solder ball, a solder column, a conductive epoxy, and a conductor-filled epoxy.

6. The electronic device package according to claim 1, wherein the plurality of optically interactive electronic devices comprise a plurality of image sensors.

7. An electronic device package comprising:

a transparent substrate;

at least one secondary substrate secured by a first surface thereof to a surface of the transparent substrate having a central aperture covered by the transparent substrate and a plurality of conductive traces positioned on the at least one secondary substrate around the central aperture, each conductive trace of the plurality of conductive traces having a first attachment point and a second attachment point on a second surface of the at least one secondary substrate;

an optically interactive electronic device having at least one bond pad, the optically interactive electronic device mounted to the at least one secondary substrate by a bond between the first attachment point of a conductive trace of the plurality of conductive traces and the at least one bond pad; and

a backing cap covering a back surface of the optically interactive electronic device, the backing cap having at least one backing cap attachment point on a surface thereof in electrical communication with the second attachment point of the conductive trace and at least one attachment pad on another surface of the backing cap in electrical communication with the at least one backing cap attachment point.

8. The electronic device package according to claim 7, further comprising:

a bond between the at least one backing cap attachment point and the second attachment point of the conductive trace, the bond comprising one of a conductive or conductor-filled epoxy, a solder joint and a layer of anisotropically conductive adhesive material.

9. The electronic device package according to claim 7, further comprising:

an array of attachment pads on the another surface of the backing cap, the array of attachment pads positioned adjacent four edges of an outer perimeter of the another surface of the backing cap.

10. The electronic device package according to claim 7, further comprising:

a discrete conductive element disposed on the at least one attachment pad on the another surface of the backing cap.

11. The electronic device package according to claim 10, wherein the discrete conductive element comprises one of a solder ball, a solder column, a conductive epoxy, and a conductor-filled epoxy.

12. The electronic device package according to claim 7, wherein the at least one secondary substrate comprises one of a printed circuit board, a polyimide film, a ceramic, and silicon.

13. The electronic device package according to claim 7, wherein an outside perimeter of the at least one secondary substrate is substantially equal to an outside perimeter of the transparent substrate.

14. The electronic device package according to claim 7, wherein the optically interactive electronic device comprises an image sensor.

15. The electronic device package according to claim 7, wherein the at least one secondary substrate comprises a plurality of secondary substrates, each secondary substrate of the plurality secured to the surface of the transparent substrate, and the at least one optically interactive device comprises a plurality of optically interactive devices.