Ultra thin image sensor package structure and method for fabrication

• US 7,521,783 B2
• Filed: 07/20/2006
• Issued: 04/21/2009
• Est. Priority Date: 06/12/2004
• Status: Active Grant

• Current Assignee: Macronix International Co., Ltd.
• Original Assignee: Macronix International Co., Ltd.
• Inventors: Lin, Chih-Wen, Tsai, Chen Jung
• Primary Examiner(s): Pert; Evan
• Assistant Examiner(s): QUINTO, KEVIN V
• Application Number:
  US11/491,392
• Publication Number:
  US 20060261428A1
• Time in Patent Office: 1,006 Days
• Field of Search: 257/414, 257/431, 257/432, 257/433, 257/444, 257/666, 257/670, 257/671, 257/678, 257/680, 257/681, 257/E23.123, 257/E23.128, 438/48, 438/57, 438/64, 438/65, 438/69
• US Class Current: 257/680
• CPC Class Codes: H01L 2224/05554 being square
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/4826 Connecting between the body and an opposite side of the item with respect to the body
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 23/49548 Cross section geometry H01L23/49562 takes precedence
• 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 2924/00014 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 2924/1815 Shape
• CPC Class Codes: H01L 2924/18165 of a wire bonded chip
• CPC Class Codes: H01L 31/0203 Containers; Encapsulations , e.g. encapsulation of photodiodesfor photovoltaic devices H01L31/048; for organic photosensitive devices H10K30/80
• CPC Class Codes: H01L 31/024 Arrangements for cooling, heating, ventilating or temperature compensation for photovoltaic devices H01L31/052
• CPC Class Codes: H01L 31/18 Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof

Abstract

An image sensor package having at least one chip supporting bar secured to a top surface of an image sensor chip. The thickness of the chip supporting bar is absorbed within a vertical dimension of wire loops that connect bonding pads to leads so that the chip supporting bar does not contribute to the thickness of the image sensor package. An exposed back surface of the image sensor chip enhances thermal dissipation.

Claims

1. An image sensor package, comprising:

a leadframe comprising a plurality of leads, each lead having a bonding surface and a non-bonding surface;

an encapsulation covering at least portions of the leads, the encapsulation forming a chip carrier cavity having an inner surface such that bonding surfaces of the leads are exposed;

an image sensor chip having an active surface and a corresponding back surface, the active surface including a light receiving area and a peripheral area having a plurality of bonding pads, the back surface being attached to the inner surface of the chip carrier cavity, wherein the back surface is at least partially exposed to enhance thermal dispersion;

a plurality of wires connecting the plurality of bonding pads and the bonding surfaces of the plurality of leads; and

a transparent lid disposed to direct light to the light receiving area.

2. The image sensor package as set forth in claim 1, wherein the back surface is attached to the inner surface by one of a liquid and a solid adhesive.

3. The image sensor package as set forth in claim 1, wherein the transparent lid comprises at least one of a flat, convex, and concave shape.

4. The image sensor package as set forth in claim 1, wherein the encapsulation is formed of ceramic material.

5. The image sensor package as set forth in claim 1, wherein the encapsulation is formed of plastic resin.

6. A method of fabricating an image sensor package, comprising:

providing an image sensor chip having an active surface and a corresponding back surface, the active surface including a light receiving area and a peripheral area having a plurality of bonding pads;

providing a leadframe including a plurality of leads and at least one elongated chip supporting bar, the at least one elongated chip supporting bar being secured to the active surface of the image sensor chip;

connecting the at least one elongated chip supporting bar to the peripheral area in a manner that does not interfere with the plurality of bonding pads;

encapsulating at least a portion of the image sensor chip, the plurality of leads, and a portion of the at least one elongated chip supporting bar in molding resin, thereby forming a cavity over the active surface; and

forming a transparent lid over the cavity whereby light can be directed to the light receiving area.

7. The method as set forth in claim 6, wherein the providing comprises providing a leadframe including a plurality of elongated chip supporting bars.

8. The method as set forth in claim 6, wherein the encapsulating is preceded by connecting a plurality of wires between the bonding pads and the plurality of leads.

9. The method as set forth in claim 6, wherein the encapsulating is followed by connecting a plurality of wires between the bonding pads and the plurality of leads.

10. The method as set forth in claim 6, wherein:

the plurality of leads comprises bonding surfaces and non-bonding surfaces;

the plurality of wires is electrically connected between the plurality of bonding pads and the bonding surfaces of the plurality of leads; and

non-bonding surfaces of the plurality of leads are not covered by the encapsulation.