Multi-functional fiber optic coupler

• US 6,635,866 B2
• Filed: 04/19/2001
• Issued: 10/21/2003
• Est. Priority Date: 04/19/2001
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hall, Richard R., Lin, How T., Chan, Benson, Sherman, John H.
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US09/838,645
• Publication Number:
  US 20020154869A1
• Time in Patent Office: 915 Days
• Field of Search: 250/239, 250/227.11, 250/214.R, 250/216, 385/92, 385/98, 385/89, 385/58, 385/69, 385/70, 385/83
• US Class Current: 250/239
• CPC Class Codes: G02B 6/3885 Multicore or multichannel optical connectors, i.e. one single ferrule containing more than one fibre, e.g. ribbon type optical ribbon cable G02B6/4403, G02B6/448
• CPC Class Codes: G02B 6/3897 Connectors fixed to housings, casing, frames or circuit boards G02B6/44528 takes precedence
• CPC Class Codes: G02B 6/4232 using the surface tension of fluid solder to align the elements, e.g. solder bump techniques flip-chip mounting techniques in assembly of semiconductor devices H01L24/81
• CPC Class Codes: G02B 6/4249 comprising arrays of active devices and fibres
• CPC Class Codes: G02B 6/4292 the light guide being disconnectable from the opto-electronic element, e.g. mutually self aligning arrangements

Abstract

An optical coupler that provides for the direct mounting of integrated circuit(s). The coupler includes a two-part housing with grooves for accommodating optical fibers that are held in place when the two parts are put together. Circuitry is formed on the housing and solder balls, when heated to a liquid state and cooled (reflowed), are used to attach integrated circuit(s) onto the housing. At least one of these integrated circuit(s) is an optical die that is positioned in close proximity to the optical fibers to provide for the receipt and/or transmission of optical signals. The reflowing of the solder balls forms an electrical connection between the circuitry on the housing and the integrated circuit(s) and provides for alignment of these components. The housing is attached to a circuitized substrate using reflowed solder balls or wirebonds.

Claims

1. An optoelectronic assembly comprising:

a substrate, a plurality of holes within said substrate parallel to a facial surface of said substrate and opening to a side surface of said substrate, a first set of conductive pads on said side surface, a first set of conductors formed on or integral with said side surface leading from the first set of conductive pads, respectively to a side edge of said substrate between said facial surface and said side surface and formed on or integral with said facial surface continuing from said side edge to circuitry on said facial surface of said substrate;

a plurality of optical transmission elements in said plurality of holes, respectively; and

an optical chip including a plurality of optical devices, said optical chip having a second set of conductive pads which are flip-chip soldered onto said first set of conductive pads on said side surface of said substrate such that (a) said plurality of optical devices of said optical chip are aligned with the plurality of optical transmission elements, respectively and (b) said optical chip is electrically connected to said first set of conductive pads.

2. An optoelectronic assembly as set forth in claim 1 wherein said optical transmission elements are optical fibers.

3. An optoelectronic assembly as set forth in claim 1 further comprising an electronic driver and/or receiver chip mounted on said facial surface of said substrate an electrically connected to said first set of conductors to provide electrical signals to and/or receive electrical signals from said optical chip.

4. An optoelectronic assembly as set forth in claim 3 further comprising:

a second electronic driver and/or receiver chip mounted on a second facial surface of said substrate opposite the first said facial surface of said substrate; and

a third set of conductive pads on said side surface, a second set of conductors formed on or integral with said side surface leading from said third set of conductive pads, respectively to a side edge of said substrate between said second facial surface and said side surface and formed on or integral with said second facial surface continuing from said side edge to connect said third set of pads to said second electronic driver and/or receiver chip so that said second electronic driver and/or receiver chip can provide electrical signals to and/or receive electrical signals from said optical chip.

5. An optoelectronic assembly as set forth in claim 1 further comprising a third set of conductive pads on said facial surface, and wherein:

said first set of conductors is electrically connected to said third set of pads, respectively, and

said electronic driver and/or receiver chip includes a fourth set of pads, said fourth set of pads being flip-chip mounted to said third set of pads on said facial surface.

6. An optoelectronic assembly as set forth in claim 1 wherein said substrate comprises two sections, each of said sections having a plurality of grooves on adjacent facial surface, said adjacent facial surfaces being bonded to each other such that the plurality of grooves of one of said sections is aligned with the plurality of grooves of the other of said sections to form said plurality of holes in said substrate.

7. An optoelectronic assembly as set forth in claim 6 wherein each of said grooves is V-shaped, a wider portion of each groove being at said adjacent facial surface.

8. An optoelectronic assembly as set forth in claim 1 further comprising a plurality of alignment pins mounted in said substrate parallel to said holes, said alignment pins protruding from said substrate to enable alignment of said optical transmission elements with another optical device.

9. An optoelectronic assembly as set forth in claim 1 wherein said optical devices are VCSELs.

10. An optoelectronic assembly as set forth in claim 1 wherein said substrate is made of a semiconductor material, and said first set of conductors are formed by doping said semiconductor material.

11. An optoelectronic assembly comprising:

a substrate, a plurality of holes within said substrate parallel to a facial surface of said substrate and opening to a side surface of said substrate;

a plurality of optical transmission elements in said plurality of holes, respectively;

an optical chip including a plurality of optical devices, said optical chip being bonded to said side surface of said substrate such that said plurality of optical devices of said optical chip are aligned with the plurality of optical transmission elements, respectively; and

wherein

said substrate comprises two planar sections, said planar sections having a plurality of grooves on adjacent facial surfaces, said adjacent facial surfaces being bonded to each other such that the plurality of grooves of one of said sections is aligned with the plurality of grooves of the other of said sections to form said plurality of holes in said substrate.

12. An optoelectronic assembly as set forth in claim 11 wherein said optical transmission elements are optical fibers.

13. An optoelectronic assembly as set forth in claim 11 wherein said optical device includes a first set of conductive pads, further comprising a second, respective set of conductive pads on said side surface, and wherein said first set of conductive pads are soldered to said second set of conductive pads, respectively.

14. An optoelectronic assembly as set forth in claim 11 wherein each of said grooves is V-shaped, a wide portion of each groove being at said second surface.

15. An optoelectronic assembly as set forth in claim 11 wherein said optical devices are VCSELs.

16. An optoelectronic assembly as set forth in claim 11 wherein said substrate is made of a semiconductor material.

17. An optoelectronic assembly comprising:

a substrate, a plurality of holes within said substrate parallel to a facial surface of said substrate and opening to a side surface of said substrate, a first set of conductive pads on said facial surface, a first set of conductors formed on or integral with said substrate, said first set of conductors interconnecting said first set of conductive pads to circuitry on said substrate;

a plurality of optical transmission elements in said plurality of holes, respectively;

an optical chip including a plurality of optical devices, said optical chip being bonded to said side surface of said substrate such that said plurality of optical devices are aligned with a respective plurality of said optical transmission elements; and

a planar printed circuit board having a second set of conductive pads on a facial surface of said printed circuit board, said printed circuit board including circuitry electrically connected to said second set of conductive pads, said first set of conductive pads of said substrate being solderd to said second set of conductive pads of said printed circuit board.

18. An optoelectronic assembly as set forth in claim 17 wherein said substrate comprises two sections, said sections having a plurality of grooves on adjacent facial surfaces thereof, said adjacent facial surfaces being bonded to each other such that the plurality of grooves of one of said sections is aligned with the plurality of grooves of the other of said sections to form said plurality of holes in said substrate.

19. An optoelectronic assembly as set forth in claim 17 wherein said optical transmission elements are optical fibers.

20. An optoelectronic assembly as set forth in claim 17 wherein said optical device includes a third set of conductive pads, further comprising a fourth, respective set of conductive pads on said side surface, and wherein said optical device is bonded to said side surface by solder between said third set of conductive pads and said fourth set of conductive pads, respectively.

21. An optoelectronic assembly as set forth in claim 17 wherein said optical devices are VCSELs.

22. An optoelectronic assembly as set forth in claim 17 wherein said circuitry on said substrate comprises an electronic driver and/or receiver chip to provide electrical signals to and/or receive electrical signals from said optical chip.

23. An optoelectronic assembly as set forth in claim 17 wherein said substrate is made of a semiconductor material and said first set of conductors are formed by doping said semiconductor material.