Low profile optocouplers

• US 7,021,839 B2
• Filed: 10/29/2002
• Issued: 04/04/2006
• Est. Priority Date: 10/29/2002
• Status: Expired due to Term

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Ho, Dominique
• Primary Examiner(s): ST CYR, DANIEL
• Application Number:
  US10/282,341
• Publication Number:
  US 20040081409A1
• Time in Patent Office: 1,253 Days
• Field of Search: 385/92, 385/93, 385/53
• US Class Current: 385/92
• CPC Class Codes: G02B 6/10 of the optical waveguide type G02B6/02, G02B6/24 take precedence; devices or arrangements for the control of light by electric, magnetic, electro-magnetic or acoustic means G02F1/00; transferring the modulation of modulated light G02F2/00; optical logic elements G02F3/00; optical analogue/digital converters G02F7/00
• CPC Class Codes: G02B 6/4295 coupling with semiconductor devices activated by light through the light guide, e.g. thyristors, phototransistors
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48464 the other connecting portion not on the bonding area also being a ball bond, i.e. ball-to-ball
• 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 31/125 Composite devices with photosensitive elements and electroluminescent elements within one single body

Abstract

Disclosed is optoelectronic device comprising a light source, a generally coplanar disposed detector, the detector detecting light from the light source, a light conductive inner mold medium encapsulating the light source and the detector, and a medium of lesser density than the light conductive medium interfaced with a surface of the light conductive medium for which light reflection is desired.

Claims

1. An optoelectronic device comprising:

a light source;

a generally coplanarly disposed detector, said detector receiving light from said light source;

a light conductive inner mold medium encapsulating said light source and said detector; and

a medium of lesser density than said light conductive medium interfaced with a surface of said light conductive medium for which light reflection is desired.

2. The device of claim 1 further comprising:

an opaque outer mold encapsulating said inner mold medium and spaced apart from said inner mold medium to thereby encapsulate said medium of lesser density.

3. The device of claim 1 further comprising a lens disposed in a light path between said light source and said detector.

4. The device of claim 3 wherein said lens is disposed on said surface of said light conductive medium.

5. The device of claim 3 wherein said lens is disposed above said light source and said detector.

6. The device of claim 5 wherein said lens is centered between said light source and said detector to focus said light from said light source on said detector.

7. The device of claim 6 wherein said lens presents a concave surface in a direction of said light source and said detector.

8. The device of claim 7 wherein said lens is ellipsoidal extending, at least in part, from over said light source to over, at least in part, said detector.

9. The device of claim 1 wherein said inner mold medium has an index of reflection greater than one.

10. The device of claim 1 wherein said medium of lesser density comprises:

a thin air film.

11. An optocoupler comprising:

a light source;

a photo detector, said photo detector detecting light from said light source;

an inner mold medium encapsulating said light source and said detector; and

a film interfaced with at least one surface of said inner mold medium, wherein a medium of said film has lesser density than said inner mold medium.

12. The device of claim 11 wherein material comprising said inner mold has an index of reflection greater than one.

13. The device of claim 11 wherein said light source are disposed substantially coplanar and said at least one surface provides reflective communication of light from said light source to said photo detector.

14. The device of claim 11 further comprising a lens disposed above and centered between said light source and said detector focusing said reflected light from said light source onto said detector.

15. The device of claim 14 wherein said lens extends, at least in part, from over said light source to over, at least in part, said detector.

16. The device of claim 14 wherein said lens is suspended in said inner mold below said film.

17. The device of claim 11 further comprising:

an opaque outer mold encapsulating said inner mold spaced apart from said inner mold.

18. A method for optoelectric detection comprising:

encapsulating an emitter and a generally coplanar detector in a transparent inner mold;

covering said inner mold with an opaque outer mold;

spacing said inner mold and said outer mold apart, defining an air gap there between;

emitting light from said light source; and

reflecting said light from said emitter to said detector using total internal reflection phenomenon.

19. The method of claim 18 wherein said encapsulating further comprises providing an inner mold material with an index of reflection greater than one.

20. The method of claim 18 further comprising disposing a lens above said light source and said detector, said lens focusing said light from said light source on said detector.