Low stress cavity package for back side illuminated image sensor, and method of making same

• US 8,604,576 B2
• Filed: 07/19/2011
• Issued: 12/10/2013
• Est. Priority Date: 07/19/2011
• Status: Active Grant

• Current Assignee: Optiz, Inc.
• Original Assignee: Opitz Incorporated
• Inventors: Oganesian, Vage
• Primary Examiner(s): Vu, David
• Assistant Examiner(s): HENRY, CALEB E
• Application Number:
  US13/186,357
• Publication Number:
  US 20130020665A1
• Time in Patent Office: 875 Days
• Field of Search: 257/432, 257/E31.127, 257/E31.126, 438/66
• US Class Current: 257/432
• CPC Class Codes: H01L 24/19 Manufacturing methods of high density interconnect preforms
• 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 27/14685 Process for coatings or optical elements
• 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 2924/12042 LASER
• CPC Class Codes: H01L 2924/181 Encapsulation

Abstract

An image sensor package includes an image sensor chip and crystalline handler. The image sensor chip includes a substrate, and a plurality of photo detectors and contact pads at the front surface of the substrate. The crystalline handler includes opposing first and second surfaces, and a cavity formed into the first surface. A compliant dielectric material is disposed in the cavity. The image sensor front surface is attached to the crystalline substrate handler second surface. A plurality of electrical interconnects each include a hole aligned with one of the contact pads, with a first portion extending from the second surface to the cavity and a second portion extending through the compliant dielectric material, a layer of insulation material formed along a sidewall of the first portion of the hole, and conductive material extending through the first and second portions of the hole and electrically coupled to the one contact pad.

Claims

1. An image sensor package, comprising:

an image sensor chip that includes;

a substrate with front and back opposing surfaces,

a plurality of photo detectors formed at the front surface, and

a plurality of contact pads formed at the front surface which are electrically coupled to the photo detectors;

a crystalline handler having opposing first and second surfaces, and a cavity formed into the first surface, wherein a compliant dielectric material is disposed in the cavity, and wherein the image sensor chip substrate front surface is attached to the crystalline substrate handler second surface;

the crystalline handler includes a plurality of electrical interconnects each comprising;

a hole aligned with one of the contact pads, with a first portion extending from the second surface to the cavity and a second portion extending through the compliant dielectric material,

a layer of insulation material formed along a sidewall of the first portion of the hole, and

conductive material extending through the first and second portions of the hole, wherein the conductive material is electrically coupled to the one contact pad.

2. The image sensor package of claim 1, wherein the compliant dielectric material includes a polymer.

3. The image sensor package of claim 1, wherein for each of the plurality of electrical interconnects, the hole is tapered such that the hole has a larger cross-sectional dimension in the compliant material than at the second surface.

4. The image sensor package of claim 1, wherein for each of the plurality of electrical interconnects, a sidewall of the hole extends in a direction between 5°

and 45°

relative to a direction that is perpendicular to the first and second surfaces.

5. The image sensor package of claim 1, wherein for each of the plurality of electrical interconnects, the conductive material comprises a layer of metal extending along sidewalls of the first and second hole portions.

6. The image sensor package of claim 1, wherein each of the plurality of electrical interconnects further comprises a rounded interconnect disposed over the first surface and electrically coupled to the conductive material.

7. The image sensor package of claim 1, further comprising:

a plurality of optical elements disposed at the back surface for filtering and focusing light incident on the back surface, wherein the photo detectors are configured to receive light passing through the optical elements and the substrate.

8. The image sensor package of claim 1, further comprising:

a glass cover attached to the back surface that extends over the optical elements.

9. The image sensor package of claim 1, wherein the compliant dielectric material completely fills the cavity.

10. The image sensor package of claim 1, further comprising:

a second cavity formed in the dielectric material; and

a processor IC chip disposed in the second cavity and configured to process signals from the image sensor chip, wherein the processor IC chip includes a plurality of contact pads.

11. The image sensor package of claim 10, further comprising:

a second layer of insulation material that extends over the processor IC chip and the first surface; and

a plurality of holes each extending through the second layer of insulation material exposing one of the contact pads of the processor IC chip.

12. The image sensor package of claim 11, further comprising:

a plurality of rounded interconnects each disposed over and electrically coupled to one of the contact pads of the processor IC chip.