Flip-chip image sensor packages and methods of fabrication

• US 6,885,107 B2
• Filed: 08/29/2002
• Issued: 04/26/2005
• 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): FORDE, REMMON R
• Assistant Examiner(s): Greene, Pershelle
• Application Number:
  US10/230,654
• Publication Number:
  US 20040041261A1
• Time in Patent Office: 971 Days
• Field of Search: 257/778, 257/773, 257/421, 257/431, 257/432, 257/455
• US Class Current: 257/778
• 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

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 formed 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;

an optically interactive electronic device having an active surface including a plurality of micro-lenses formed over a portion of the active surface and at least one bond pad, the optically interactive electronic device mounted to the transparent substrate by at least one conductive bump bonded between the first attachment point of a conductive trace of the plurality of conductive traces and the at least one bond pad, wherein the at least one conductive bump has a thickness providing a gap between the plurality of micro-lenses and the surface of the transparent substrate; and

a discrete conductive element attached to the second attachment point of the conductive trace, the discrete conductive element extending outwardly from the transparent substrate within an outside perimeter thereof from the second attachment point in a direction perpendicular to a plane of the surface of the transparent substrate and to a level beyond a back surface of the optically interactive electronic device.

2. The electronic device package according to claim 1, wherein the second attachment points of the plurality of conductive traces are located in at least one row extending adjacent a perimeter portion of the surface of the transparent substrate.

3. The electronic device package according to claim 2, wherein the second attachment points of the plurality of conductive traces are located in multiple rows extending adjacent the perimeter portion of the surface of the transparent substrate.

4. The electronic device package according to claim 1, wherein the plurality of conductive traces comprises a material from the group consisting of a conductive epoxy, a conductor-filled epoxy, a conductive resin, a conductor-filled resin, a polysilicon, a metal and an alloy.

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

a bead of sealant material disposed between and contacting at least one side of the optically interactive electronic device and the surface of the transparent substrate.

6. The electronic device package according to claim 5, wherein the bead of sealant material comprises one of epoxy and silicone.

7. The electronic device package according to claim 1, wherein the discrete conductive element comprises one of a solder ball, a solder column, a conductive epoxy, and a conductor-filled epoxy.

8. The electronic device package according to claim 1, wherein the optically interactive electronic device comprises an image sensor.