Methods for packaging image sensitive electronic devices

• US 7,195,940 B2
• Filed: 02/21/2003
• Issued: 03/27/2007
• Est. Priority Date: 06/04/2002
• Status: Expired due to Fees

• Current Assignee: SuperMax Technology Ltd.
• Original Assignee: Micron Technology, Inc.
• Inventors: Cobbley, Chad A., Bolken, Todd O.
• Primary Examiner(s): Graybill; David E.
• Application Number:
  US10/370,674
• Publication Number:
  US 20030232461A1
• Time in Patent Office: 1,495 Days
• Field of Search: 438/106, 438/107, 438/108, 438/116, 438/126, 438/127, 438/125, 438/25, 438/26, 438/27, 438/29, 257/678
• US Class Current: 438/25
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/32145 the bodies being stacked
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48145 the bodies being stacked
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/484 Connecting portions
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 2224/92 Specific sequence of method steps
• CPC Class Codes: H01L 2224/92247 the second connecting process involving a wire connector
• CPC Class Codes: H01L 2225/06506 Wire or wire-like electrical connections between devices
• CPC Class Codes: H01L 2225/06555 Geometry of the stack, e.g. form of the devices, geometry to facilitate stacking
• CPC Class Codes: H01L 23/293 Organic, e.g. plastic
• CPC Class Codes: H01L 23/3128 the substrate having spherical bumps for external connection
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/73 Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 25/0657 : Stacked arrangements of devices
• CPC Class Codes: H01L 27/14603 : Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
• 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 27/14683 : 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 2924/00011 : Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/15174 : in different layers of the multilayer substrate
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/1815 : Shape
• 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: Y10S 257/924 : with passive device, e.g. capacitor, or battery, as integral part of housing or housing element, e.g. cap

Abstract

The invention provides methods for packaging for electronic devices that are light or other radiation-sensitive, such as image sensors including CCD or CMOS chips. In one embodiment of the invention, an image sensor package is assembled by surrounding a chip with a barrier of transfer mold compound and covering the chip with a transparent lid. In another embodiment of the invention, the perimeter area of a chip, including interconnections such as wire bonds and bond pads, is encapsulated with a liquid dispensed epoxy, and a transparent lid is attached. In yet another embodiment of the invention, chip encapsulation is accomplished with a unitary shell of entirely transparent material. In yet another embodiment of the invention, a substrate-mounted chip and a transparent lid are loaded into a transfer mold that holds them in optimal alignment. The transfer mold is then filled with molding compound to encapsulate the chip and interconnections, and to retain the transparent lid.

Claims

1. A method for assembling at least one package containing an electronic device sensitive to light or other radiation comprising:

mounting the electronic device on a carrier substrate comprising a contiguous planar structure having at least one conductive trace thereon, the at least one conductive trace having a first end comprising a terminal pad on a first surface of the carrier substrate and a second end comprising an attachment pad on a second, opposing surface of the carrier substrate;

providing at least one electrical interconnection between a bond pad on the electronic device and the first end of the at least one conductive trace;

forming a molded barrier on the carrier substrate prior to mounting the electronic device, the molded barrier surrounding a central exposed area that contains the electronic device and the at least one electrical interconnection; and

filling the central exposed area of the molded barrier with a clear compound to form a transparent shell that encapsulates the electronic device, the bond pad, and the at least one electrical interconnection.

2. The method according to claim 1, further comprising supporting a transparent lid on a ledge formed on an inner perimeter of the molded barrier.

3. The method according to claim 1, further comprising forming a surface of the transparent shell into the shape of a lens.

4. The method according to claim 1, further comprising fixing a transparent lid over the central exposed area by applying an activated adhesive between an outer perimeter of the transparent lid and an inner perimeter of the molded barrier and setting the activated adhesive.

5. The method according to claim 1, wherein mounting the electronic device comprises providing an image sensor.

6. The method according to claim 1, further comprising selecting the electronic device to comprise a solid-state device comprising at least one of a charge coupled device, a complementary metal-oxide semiconductor and an erasable programmable read-only memory.

7. The method according to claim 6, further comprising fabricating the electronic device to comprise a plurality of semiconductor devices.

8. The method according to claim 1, further comprising forming the carrier substrate of a material comprising at least one of plastic, FR-4 and BT.

9. The method according to claim 8, further comprising:

attaching at least one discrete conductive element to the second end of the at least one conductive trace of the carrier substrate.

10. The method according to claim 9, further comprising:

mounting a plurality of electronic devices onto the carrier substrate; and

dividing the carrier substrate into separate pieces, each of the pieces comprising a package including one electronic device of the plurality of electronic devices.