OPTOELECTRONIC BALL GRID ARRAY PACKAGE WITH FIBER

• US 20160124164A1
• Filed: 10/29/2015
• Published: 05/05/2016
• Est. Priority Date: 10/29/2014
• Status: Active Grant

• Current Assignee: Acacia Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Acacia Communications Incorporated (Cisco Systems, Inc.)
• Inventors: Doerr, Christopher
• Granted Patent: US 11,360,278 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 6/30 for use between fibre and thin-film device
• CPC Class Codes: G02B 6/3616 Holders, macro size fixtures for mechanically holding or positioning fibres, e.g. on an optical bench supporting carriers of a microbench type G02B6/3648; micromanipulators B25J7/00; cassettes, bobbins G02B6/4439
• CPC Class Codes: G02B 6/4202 for coupling an active element with fibres without intermediate optical elements, e.g. fibres with plane ends, fibres with shaped ends, bundles
• CPC Class Codes: G02B 6/4204 the coupling comprising intermediate optical elements, e.g. lenses, holograms encapsulated active devices H01S5/02208, H01L33/52
• CPC Class Codes: G02B 6/423 using guiding surfaces for the alignment
• 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 6/424 Mounting of the optical light guide
• CPC Class Codes: G02B 6/4245 Mounting of the opto-electronic elements
• CPC Class Codes: G02B 6/4249 comprising arrays of active devices and fibres
• CPC Class Codes: G02B 6/4267 Reduction of thermal stress, e.g. by selecting thermal coefficient of materials
• CPC Class Codes: G02B 6/4269 with heat sinks or radiation fins
• CPC Class Codes: G02B 6/4272 with mounting substrates of high thermal conductivity
• CPC Class Codes: G02B 6/4273 with heat insulation means to thermally decouple or restrain the heat from spreading
• CPC Class Codes: G02B 6/428 containing printed circuit boards [PCB]
• CPC Class Codes: G02B 6/4457 Bobbins; Reels
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors

Abstract

A photonic integrated circuit may be coupled to an optical fiber and packaged. The optical fiber may be supported by a fiber holder during a solder reflow process performed to mount the packaged photonic integrated circuit to a circuit board or other substrate. The optical fiber may be decoupled from the fiber holder, and the fiber holder removed, after completion of the solder reflow process.

Claims

1. An apparatus, comprising:

a substrate having a first surface;

a photonic integrated circuit (PIC) coupled to the substrate and having a first surface proximate the first surface of the substrate and a second surface opposite the first surface of the PIC and distal the first surface of the substrate;

a lid, contacting the first surface of the substrate;

a fiber holder disposed on the lid; and

an optical fiber coupled to the PIC and in contact with the fiber holder.

2. The apparatus according to claim 1, wherein a portion of the optical fiber is coiled around the fiber holder.

3. The apparatus according to claim 2, wherein the portion of the optical fiber is coiled around the fiber holder within a plane that is substantially parallel to the second surface of the PIC.

4. The apparatus according to claim 1, wherein the optical fiber is edge-coupled to the PIC.

5. The apparatus according to claim 1, further comprising an electronic integrated circuit disposed on the first surface of the substrate.

6. The apparatus according to claim 1, further comprising a circuit board on which the substrate in mounted.

7. The apparatus according to claim 6, wherein the substrate is electrically connected to the circuit board through a ball grid array.

8. The apparatus according to claim 1, wherein the fiber holder is made of copper.

9. The apparatus according to claim 1, further comprising an interposer having a first surface proximate the first surface of the substrate and a second surface opposite the first surface of the interposer and proximate the first surface of the PIC.

10. The apparatus according to claim 1, further comprising a fiber assembly containing a groove on which the optical fiber is disposed.

11. The apparatus according to claim 10, further comprising a thermal pad contacting the fiber assembly.

12. A method, comprising:

packaging a photonic integrated circuit (PIC) in a package comprising a substrate and a lid;

mounting a fiber holder on the lid of the package such that the lid is between the PIC and the fiber holder;

coupling an optical fiber to the PIC;

mechanically coupling the optical fiber to the fiber holder.

13. The method according to claim 12, further comprising surface-mounting the package on a chip carrier.

14. The method according to claim 13, further comprising securing an end of the optical fiber on the fiber holder.

15. The method according to claim 12, further comprising performing reflow soldering of the package.

16. The method according to claim 15, further comprising removing the fiber holder from the package subsequent to the reflow soldering.

17. The method according to claim 12, wherein mechanically coupling the optical fiber to the fiber holder comprises coiling a portion of the optical fiber around the fiber holder.

18. The method according to claim 17, wherein the portion of the optical fiber is coiled around the fiber holder with a radius that is less than a minimum bend radius of the optical fiber.

19. The method according to claim 12, further comprising splicing the optical fiber to an optical component.

20. The method according to claim 12, wherein mounting the fiber holder on the lid of the package comprises mounting the fiber holder with at least one screw inserted on the lid.

21. An apparatus, comprising:

a substrate having a first surface;

a photonic integrated circuit (PIC) coupled to the substrate and having a first surface proximate the first surface of the substrate and a second surface opposite the first surface of the PIC and distal the first surface of the substrate;

a lid, contacting the first surface of the substrate and at least partially covering the PIC, exhibiting at least one retaining feature; and

an optical fiber coupled to the PIC and in contact with the retaining feature of the lid.

22. The apparatus of claim 21, wherein the retaining feature comprises a groove in the lid.

23. The apparatus of claim 21, wherein the retaining feature comprises a fiber channel.

24. The apparatus of claim 21, wherein the lid is formed of a thermally conductive material.