Radiation sensor device and method

• US 20070063145A1
• Filed: 05/18/2006
• Published: 03/22/2007
• 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 7,897,920 B2
• Time in Patent Office: Days
• US Class Current: 250/370.140
• CPC Class Codes: G01J 5/041 Mountings in enclosures or in a particular environment
• CPC Class Codes: G01J 5/045 Sealings; Vacuum enclosures; Encapsulated packages; Wafer bonding structures; Getter arrangements getter arrangements per se H01L23/26 and H01L21/3221
• CPC Class Codes: G01J 5/0884 Monolithic
• 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 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 2924/00014 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 31/0203 Containers; Encapsulations , e.g. encapsulation of photodiodesfor photovoltaic devices H01L31/048; for organic photosensitive devices H10K30/80

Abstract

An improved radiation sensor device includes a cap attached to an integrated circuit chip which has a radiation sensor on a surface with a cap spaced from and covering the radiation sensor; the cap and integrated circuit chip with radiation sensor are encapsulated in an encapsulant with a transparent portion of at least one of the cap and integrated circuit chip proximate the radiation sensor being exposed at the boundary of the encapsulant.

Claims

1. A radiation sensor device comprising:

an integrated circuit chip including an integral radiation sensor on a surface of said integrated circuit chip; and

a cap attached to said integrated circuit chip spaced from and covering said radiation sensor, at least one of said cap and said integrated circuit chip having at least a portion proximate said radiation sensor transparent to the radiation to be sensed.

2. The radiation sensor device of claim 1 in which said radiation sensor is on the active surface of said integrated circuit chip and said cap includes a radiation transparent portion.

3. The radiation sensor device of claim 1 in which said radiation sensor is on the inactive surface of said integrated circuit chip and said integrated circuit includes a radiation transparent portion.

4. The radiation sensor device of claim 1 in which said integrated circuit chip includes solder bump connectors on its active surface.

5. The radiation sensor device of claim 1 in which said integrated circuit chip includes solder bump connectors on its inactive surface.

6. The radiation sensor device of claim 1 in which said cap and said integrated circuit chip with said radiation sensor are disposed in an encapsulant with the inactive surface exposed at a boundary of said encapsulant.

7. The radiation sensor device of claim 6 in which said at least a portion of said integrated circuit proximate said radiation sensor is transparent to the radiation to be sensed.

8. The radiation sensor device of claim 1 in which said cap and said integrated circuit chip with said radiation sensor are disposed in an encapsulant with the cap exposed at the boundary of said encapsulant.

9. The radiation sensor device of claim 8 in which at least a portion of said cap proximate said radiation sensor is transparent to the radiation being sensed.

10. The radiation sensor device of claim 1 in which said cap and integrated circuit chip with said radiation sensor are disposed in an encapsulant along with a lead frame.

11. The radiation sensor device of claim 10 in which said lead frame includes an exposed paddle.

12. The radiation sensor device of claim 10 in which said lead frame includes a hidden paddle.

13. The radiation sensor device of claim 10 in which said integrated circuit chip is flip-chip attached to said lead frame.

14. The radiation sensor device of claim 1 in which said cap and integrated circuit chip with said radiation sensor are disposed in an encapsulant.

15. The radiation sensor device of claim 14 in which said encapsulant includes a recess.

16. The radiation sensor device of claim 15 in which said cap is exposed in said recess.

17. The radiation sensor device of claim 15 in which said integrated circuit chip is exposed in said recess.

18. The radiation sensor device of claim 1 further including a pre-molded package with a base for supporting said cap and said integrated circuit chip with radiation sensor.

19. The radiation sensor device of claim 18 further including said pre-molded package filled with an encapsulant up to and not covering said cap.

20. The radiation sensor device of claim 18 in which said pre-molded package includes a lid above said cap and having at least a portion transparent to the radiation to be sensed.

21. The radiation sensor device of claim 8 in which said sensor is an infrared radiation sensor.

22. The radiation sensor device of claim 21 in which said transparent portion is transparent to infrared radiation.

23. The radiation sensor device of claim 1 in which said cap provides a vacuum at said radiation sensor.

24. The radiation sensor device of claim 2 in which said cap includes a lens.

25. The radiation sensor device of claim 14 in which said encapsulant includes plastic.

26. The radiation sensor device of claim 14 in which said encapsulant includes epoxy.

27. A radiation sensor device comprising:

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

a cap attached to said integrated circuit chip spaced from and covering said radiation sensor, at least one of said cap and said integrated circuit chip having at least a portion proximate said radiation sensor transparent to the radiation to be sensed; and

an encapsulant encapsulating said cap and said integrated circuit chip with radiation sensor with a said transparent portion exposed at a boundary of said encapsulant.

28. The radiation sensor device of claim 27 in which said encapsulant includes plastic.

29. A method of forming a radiation sensor device comprising:

attaching a cap to an integrated circuit chip, having a radiation sensor on a surface, with the cap spaced from and covering said radiation sensor; and

encapsulating said cap and integrated circuit chip with said radiation sensor in an encapsulant with a transparent portion of at least one of said cap and integrated circuit chip proximate said radiation sensor being exposed at the boundary of said encapsulant.

30. The method of claim 29 in which said encapsulant includes a plastic.

31. The method of claim 29 in which a vacuum is formed about said radiation sensor in said cap.

32. The method of claim 29 in which a sacrificial layer is formed over a transparent portion and etched away to remove any mold bleed occurring at the transparent portion.

33. The method of claim 29 in which a compliant layer is formed over a transparent portion to prevent mold bleed occurring at the transparent portion and protect the transparent portion.

34. The method of claim 33 in which a compliant layer includes a void.