Radiation sensor device and method

• US 20090218492A1
• Filed: 12/04/2008
• Published: 09/03/2009
• Est. Priority Date: 09/21/2005
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Kierse, Oliver, Hynes, Eamon
• Granted Patent: US 8,476,591 B2
• Time in Patent Office: Days
• US Class Current: 250/338.400
• CPC Class Codes: G01J 1/04 Optical or mechanical part supplementary adjustable parts
• CPC Class Codes: G01J 1/0403 Mechanical elements; Supports for optical elements; Scanning arrangements
• CPC Class Codes: G01J 1/0407 Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
• CPC Class Codes: G01J 5/024 Special manufacturing steps or sacrificial layers or layer structures
• CPC Class Codes: G01J 5/0875 Windows; Arrangements for fastening thereof
• CPC Class Codes: H01L 2224/16245 the item being metallic
• 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 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 27/1446 in a repetitive configuration
• CPC Class Codes: H01L 27/14618 Containers
• CPC Class Codes: H01L 27/14634 Assemblies, i.e. Hybrid structures
• 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 2924/16235 Connecting to a semiconductor or solid-state bodies, i.e. cap-to-chip
• 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: H01L 31/101 Devices sensitive to infrared, visible or ultraviolet radiation

Abstract

A radiation sensor device including an integrated circuit chip including a radiation sensor on a surface of the integrated chip, one or more electrical connections configured to connect between an active surface of the integrated circuit chip and a lead frame, a cap attached to said integrated circuit chip spaced from and covering said radiation sensor, the cap having a transparent portion defining a primary lens transparent to the radiation to be sensed, a secondary lens disposed in a recess proximate and spaced from said primary lens transparent to the radiation to be sensed, and an air gap between said primary lens and said secondary lens.

Claims

1. A radiation sensor device comprising:

an integrated circuit chip including a radiation sensor on a surface of the integrated chip;

one or more electrical connections configured to connect between an active surface of the integrated circuit chip and a lead frame;

a cap attached to said integrated circuit chip spaced from and covering said radiation sensor, the cap having a transparent portion defining a primary lens transparent to the radiation to be sensed;

a secondary lens disposed in a recess proximate and spaced from said primary lens transparent to the radiation to be sensed; and

an air gap between said primary lens and said secondary lens.

2. The radiation sensor device of claim 1 in which said electrical connections include wire leads.

3. The radiation sensor device of claim 1 in which said electrical connections include solder bump connectors.

4. The system of claim 1 in which the secondary lens in the recess does not protrude above a top surface of the radiation sensor device.

5. The system of claim 1 in which the secondary lens is chosen to enhance and optimize the sensitivity of the radiation sensor device.

6. The radiation sensor device of claim 1 in which said lead frame includes a paddle.

7. A radiation sensor device comprising:

an integrated circuit chip including a radiation sensor on a surface of the integrated chip and leads configured to provide a connection to an active surface of the integrated circuit chip and for mounting the integrated circuit chip on leads and/or a circuit board;

one or more electrical connections configured to connect between an active surface of the integrated circuit chip and a lead frame;

a cap attached to said integrated circuit chip spaced from and covering said radiation sensor, the cap having a transparent portion defining a primary lens transparent to the radiation to be sensed;

an encapsulant for encapsulating said cap and said integrated circuit chip with said radiation sensor having said primary lens exposed at a boundary of said encapsulant;

a secondary lens disposed in a recess proximate and spaced from said primary lens transparent to the radiation to be sensed; and

an air gap between said primary lens and said secondary lens.

8. A method for forming a radiation sensor device comprising:

attaching a cap to an integrated circuit chip having a radiation sensor thereon and electrical connections coupled to a lead frame, the cap spaced from and covering said radiation sensor and having a primary lens for receiving radiation;

placing said cap and said integrated circuit chip coupled to said lead frame in a bottom mold plate of a mold;

applying a stretch film over a top mold plate having one or more protrusions for defining a recess for a secondary lens and a recess for an air gap;

securing said top mold plate to said bottom mold plate;

injecting an encapsulant into the secured top mold plate and bottom mold plate;

removing the top plate with the thin plate thereon from the bottom mold plate;

attaching a secondary lens to the recess for the secondary lens; and

removing said cap and said integrated chip having a radiation sensor thereon and electrical connections coupled to said lead frame and said secondary lens attached thereto from the bottom mold plate.

9. The system of claim 8 in which the secondary lens is chosen to enhance and optimize the sensitivity of the radiation sensor device.

10. The system of claim 9 in which the height of the recess for the secondary lens is adjusted to accommodate the secondary lens.

11. A method for forming a radiation sensor device comprising:

attaching a cap to an integrated circuit chip having a radiation sensor thereon and electrical connections coupled to a lead frame, the cap spaced from and covering said radiation sensor and having a primary lens for receiving radiation;

placing said cap and said integrated circuit chip coupled to said lead frame in a bottom mold plate of a mold;

securing a top mold plate having one or more protrusions for defining a recess for a secondary lens and a recess for an air gap to said bottom mold plate;

injecting an encapsulant into the secured top mold plate and bottom mold plate;

removing the top plate with the thin plate thereon from the bottom mold plate;

attaching a secondary lens to the recess for the secondary lens; and

removing said cap and said integrated chip having a radiation sensor thereon and electrical connections coupled to said lead frame and said secondary lens attached thereto from the bottom mold plate.

12. The system of claim 11 in which the secondary lens is chosen to enhance and optimize the sensitivity of the radiation sensor device.