Infrared proximity sensor package with reduced crosstalk

• US 8,217,482 B2
• Filed: 12/21/2007
• Issued: 07/10/2012
• Est. Priority Date: 12/21/2007
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Basoor, Suresh, Ng, Peng Yam, Chen, Deng Peng
• Primary Examiner(s): Parekh, Nitin
• Application Number:
  US11/962,535
• Publication Number:
  US 20090159900A1
• Time in Patent Office: 1,663 Days
• Field of Search: 257/436, 257/98, 257/99, 257/100, 257/432, 257/433, 257/E25.032, 257/E33.059, 438/30, 438/25, 438/27, 438/48, 438/65
• US Class Current: 257/436
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 7/4813 Housing arrangements
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• 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 2924/12043 Photo diode
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/1433 Application-specific integrated circuit [ASIC]
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/207 Diameter ranges

Abstract

Disclosed are various embodiments of an infrared proximity sensor package comprising an infrared transmitter die, an infrared receiver die, a housing comprising outer sidewalls, a first recess, a second recess and a partitioning divider disposed between the first and second recesses. The transmitter die is positioned in the first recess, the receiver die is positioned within the second recess, and at least the partitioning divider of the housing comprises liquid crystal polymer (LCP) such that infrared light internally-reflected within the housing in the direction of the partitioning divider is substantially attenuated or absorbed by the LCP contained therein.

Claims

1. An infrared proximity sensor package, comprising:

an infrared transmitter die;

an infrared receiver die;

a housing comprising outer sidewalls, a first recess, a second recess and a partitioning divider disposed between the first and second recesses;

wherein the transmitter die is disposed in the first recess, the receiver die is disposed in the second recess, and at least the partitioning divider comprises liquid crystal polymer (LCP) such that infrared light internally-reflected within the housing in the direction of the partitioning divider is substantially attenuated or absorbed by the LCP contained therein.

2. The infrared proximity sensor package of claim 1, further comprising a lead frame configured to fit beneath the housing, have the transmitter die disposed on a first frame portion thereof and have the receiver die disposed on a second frame portion thereof such that the transmitter die is positioned within the first recess and the receiver die is positioned within the second recess.

3. The infrared proximity sensor package of claim 1, wherein the outer sidewalls comprise LCP such that infrared light internally-reflected within the housing in the direction of the outer sidewalls is substantially attenuated or absorbed by the LCP contained therein.

4. The infrared proximity sensor package of claim 1, wherein an upper housing portion comprises LCP such that infrared light internally-reflected within the housing in the direction of the upper housing portion is substantially attenuated or absorbed by the LCP contained therein.

5. The infrared proximity sensor package of claim 1, wherein a lower housing portion comprises LCP such that infrared light internally-reflected within the housing in the direction of the lower housing portion is substantially attenuated or absorbed by the LCP contained therein.

6. The infrared proximity sensor package of claim 1, wherein the housing is molded from LCP.

7. The infrared proximity sensor package of claim 1, wherein at least portions of the lead frame are moldably integrated into the housing.

8. The infrared proximity sensor package of claim 1, further comprising a processor die operably coupled to the transmitter die and the receiver die, the processor die comprising transmitter driving circuitry, receiver detection circuitry and signal conditioning circuitry.

9. The infrared proximity sensor package of claim 1, wherein the transmitter die comprises an infrared LED transmitter.

10. The infrared proximity sensor package of claim 1, wherein the receiver die comprises at least one of a PIN diode, a photo-diode and a phototransistor.

11. The infrared proximity sensor package of claim 1, wherein at least one of the transmitter die and the receiver die is configured for operation within a bandwidth ranging between about 800 nm and about 1100 nm, or between about 850 nm and about 900 nm.

12. The infrared proximity sensor package of claim 1, wherein an edge of the transmitter die closest to an edge of the receiver die is less than about 2 mm.

13. The infrared proximity sensor package of claim 1, further comprising a plurality of terminal pins configured to permit an electrical connection of the package to one or more electronic devices external thereto.

14. The infrared proximity sensor package of claim 1, wherein at least one of the transmitter die and receiver die are wirebonded to selected terminal pins integrated into the package.

15. The infrared proximity sensor package of claim 14, wherein the lens is configured to act as a low-cut filter that at least partially rejects wavelengths of light less than about 700 nm.

16. The infrared proximity sensor package of claim 14, wherein the lens is formed from a thermoset epoxy or a polymer.

17. The infrared proximity sensor package of claim 1, wherein the lead frame is a quad flat no lead (QFN) lead frame.

18. The infrared proximity sensor package of claim 1, wherein the sensor package is incorporated into an electronic device selected from the group consisting of a portable electronic device, a hand-held portable electronic device, a stationary electronic device, a washing machine, a dryer, an exercise machine, an industrial control or switching device, a camera, a toy, a mobile telephone, a cellular telephone, a portable music player, a remote control, a television, an air conditioning unit, a heating unit, an audio playback device, an audio recording device, an MP3 player, a laptop computer, a personal data assistant (PDA), a radio, and a transceiver.

19. The infrared proximity sensor package of claim 1, wherein the sensor package is incorporated into a telephone and operably connected to at least one of an auto-volume adjustment circuit and an open-phone detection circuit.

20. The infrared proximity sensor package of claim 1, further comprising a lens disposed over at least one of the transmitter die and the receiver die.

21. The infrared proximity sensor package of claim 1, wherein the partitioning divider has a thickness less than about 0.4 mm.

22. The infrared proximity sensor package of claim 1, wherein at least one of a length and a width of the package is less than about 5 mm.

23. The infrared proximity sensor package of claim 1, wherein a height of the package is less than at least one of about 3 mm, about 2 mm, and about 1.2 mm.

24. A method of making an infrared proximity sensor package, comprising:

providing an infrared transmitter die;

providing an infrared receiver die;

providing a housing comprising outer sidewalls, a first recess, a second recess, and a partitioning divider disposed between the first recess and the second recess, at least the partitioning divider comprising liquid crystal polymer (LCP) such that infrared light internally-reflected within the housing in the direction of the partitioning divider is substantially attenuated or absorbed by the LCP contained therein;

positioning the transmitter die within the first recess, and

positioning the receiver die within the second recess.

25. The method of claim 24, further comprising providing a lead frame configured to fit beneath the housing and engage lower portions thereof.

26. The method of claim 25, further comprising providing the lead frame with first and second frame portions.

27. The method of claim 26, further comprising attaching the lead frame to a lower housing portion.

28. The method of claim 26, further comprising disposing the transmitter die on the first frame portion.

29. The method of claim 26, further comprising disposing the receiver die on the second frame portion.

30. The method of claim 24, further comprising molding the housing from a LCP.

31. The method of claim 24, further comprising integrably molding at least portions of the lead frame into the housing.