Radiation sensor device and method

• US 8,476,591 B2
• Filed: 12/04/2008
• Issued: 07/02/2013
• Est. Priority Date: 09/21/2005
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Kierse, Oliver, Hynes, Eamon
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): Malevic, Djura
• Application Number:
  US12/315,541
• Publication Number:
  US 20090218492A1
• Time in Patent Office: 1,671 Days
• Field of Search: 250/338.4, 250/239, 250/370.14, 250/353, 250/352
• US Class Current: 250/338.1
• 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 the primary lens having a first lens focal point;

a secondary lens disposed in a recess proximate and spaced from said primary lens transparent to the radiation to be sensed, the secondary lens having a secondary lens focal point; 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 radiation sensor device of claim 1 in which said lead frame includes a paddle.

6. A radiation sensor device having a plurality of lenses, each lens having a focal point, the 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.

7. 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, the primary lens having a first lens focal point;

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, the secondary lens having a secondary lens focal point; 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.

8. The method of claim 7 in which the height of the recess for the secondary lens is configured such that he secondary lens does not protrude from the encapsulant.

9. A method for forming a radiation sensor device having a plurality of lenses, each lens having a focal point, the method 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.

10. The method of claim 9 in which the secondary lens is within the recess and does not protrude from the encapsulant.