Methods for packaging an image sensor and a packaged image sensor

• US 20060268144A1
• Filed: 05/27/2005
• Published: 11/30/2006
• Est. Priority Date: 05/27/2005
• Status: Active Grant

• Current Assignee: Aptina Imaging Corporation (ON Semiconductor Corporation)
• Original Assignee: Aptina Imaging Corporation (ON Semiconductor Corporation)
• Inventors: Tan, Cheng Why, Seow, Piang Joon
• Granted Patent: US 7,745,897 B2
• Time in Patent Office: Days
• US Class Current: 348/340
• CPC Class Codes: H01L 2224/05554 being square
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/4554 Coating
• 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 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/48471 the other connecting portion not on the bonding area being a ball bond, i.e. wedge-to-ball, reverse stitch
• CPC Class Codes: H01L 2224/48479 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 2224/85951 Forming additional members, e.g. for reinforcing
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• 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 2924/00012 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 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/1815 : Shape
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H04N 23/54 : Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils

Abstract

An image sensor is packaged by attaching the image sensor to a substrate, forming metallic bumps on either the image sensor or a transparent cover, where the metallic bumps are formed in a pattern around the perimeter of the active area of the image sensor. The transparent cover is then glued to the image sensor at the metallic bumps. Electrical connections are formed between the image sensor and the substrate using, for example, conventional wire bonding techniques. The electrical connections are encapsulated within an epoxy for protection. In an embodiment, multiple image sensors are packaged together on the same substrate and separated into individually packaged image sensors by, for example, sawing.

Claims

1. A method for packaging image sensors, the method comprising:

attaching an image sensor to a substrate, wherein the image sensor has an active area;

forming metallic bumps on one of the image sensor or a transparent cover, wherein the metallic bumps are formed in a pattern around the perimeter of the active area of the image sensor; and

gluing the transparent cover to the image sensor at the metallic bumps.

2. The method of claim 1 wherein the metallic bumps have uniform heights.

3. The method of claim 1 wherein the metallic bumps are gold.

4. The method of claim 1 wherein the metallic bumps are formed with wire bonding equipment.

5. The method of claim 1 wherein gluing the transparent cover to the image sensor at the metallic bumps comprises dispensing an adhesive around the perimeter of the active area of the image sensor.

6. The method of claim 1 wherein gluing the transparent cover to the image sensor at the metallic bumps comprises dispensing an adhesive around the perimeter of the active area of the image sensor such that the active area of the image sensor is encapsulated within a cavity formed by the image sensor, the metallic bumps, the transparent cover, and the adhesive.

7. The method of claim 1 further comprising creating electrical connections between the image sensor and the substrate.

8. The method of claim 7 wherein the electrical connections are created before the transparent cover is glued to the image sensor.

9. The method of claim 7 wherein the electrical connections are created after the transparent cover is glued to the image sensor.

10. The method of claim 7 further comprising dispensing epoxy over the electrical connections to encapsulate the electrical connections.

11. The method of claim 10 further comprising separating the image sensors from a matrix of image sensors that are attached to the same substrate.

12. A method for packaging image sensors, the method comprising:

attaching an image sensor to a substrate, wherein the image sensor has an active area;

forming metallic bumps on the image sensor around the active area of the image sensor;

dispensing adhesive on the metallic bumps;

placing a transparent cover in contact with the adhesive and over the active area of the image sensor; and

curing the adhesive to secure the transparent cover to the image sensor.

13. The method of claim 12 wherein the adhesive is dispensed around the perimeter of the active area of the image sensor.

14. The method of claim 12 wherein the adhesive is dispensed around the perimeter of the active area of the image sensor such that the active area of the image sensor is encapsulated within a cavity formed by the image sensor, the metallic bumps, the transparent cover, and the adhesive.

15. A packaged image sensor comprising:

a substrate;

an image sensor attached to the substrate, wherein the image sensor has an active area;

electrical connections between the image sensor and the substrate;

a transparent cover large enough to cover the active area of the image sensor;

metallic bumps between the image sensor and the transparent cover in a pattern around the perimeter of the active area of the image sensor; and

adhesive between the image sensor and the transparent cover around the perimeter of the active area in a pattern that corresponds to the metallic bumps, wherein the adhesive connects the transparent cover and the image sensor.

16. The packaged image sensor of claim 15 wherein the image sensor, the transparent cover, the metallic bumps, and the adhesive encapsulate the active area of the image sensor.

17. The packaged image sensor of claim 16 further including epoxy formed over the electrical connections to encapsulate the electrical connections.

18. The packaged image sensor of claim 15 wherein the metallic bumps are formed on the image sensor.

19. The packaged images sensor of claim 18 wherein the metallic bumps are formed on bond pads of the image sensor.

20. The packaged image sensor of claim 15 wherein the metallic bumps are formed on the transparent cover.