Methods and apparatus to mount a waveguide to a substrate

• US 20060291771A1
• Filed: 06/24/2005
• Published: 12/28/2006
• Est. Priority Date: 06/24/2005
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Lu, Daoqiang, Braunisch, Henning, Arbizu, Nathaniel
• Granted Patent: US 7,684,660 B2
• Time in Patent Office: Days
• US Class Current: 385/15
• 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 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: G02B 6/4224 using visual alignment markings, e.g. index methods
• CPC Class Codes: G02B 6/4239 Adhesive bonding; Encapsulation with polymer material
• CPC Class Codes: G02B 6/4249 comprising arrays of active devices and fibres
• CPC Class Codes: H01L 2224/14 of a plurality of bump connectors
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation

Abstract

Methods and apparatus to mount an optical waveguide to a substrate are disclosed. A disclosed method involves providing a substrate having a first layer and a second layer. The first layer includes at least one alignment fiducial and the second layer covers the at least one fiducial. At least a portion of the second layer is removed to render the fiducial visible and a waveguide is automatically aligned with the first fiducial. The waveguide is then fixed to the substrate.

Claims

1. A method of mounting an optical waveguide to a substrate, comprising:

providing a substrate having a first layer and a second layer, the first layer including at least one alignment fiducial, the second layer covering the at least one fiducial;

removing at least a portion of the second layer to render the at least one fiducial visible;

automatically aligning a waveguide with the first fiducial; and

fixing the waveguide to the substrate.

2. A method as defined in claim 1, wherein rendering the fiducial visible comprises making the fiducial visible to a vision recognition device, and wherein automatically aligning the waveguide comprises using at least one of the vision recognition device and a pick-and-place device to align the waveguide with the fiducial.

3. A method as defined in claim 1, further comprising securing at least one circuit element to the substrate before removing the at least a portion of the second layer.

4. A method as defined in claim 1, further comprising disposing an ultraviolet light-activated adhesive on the substrate to fix the waveguide to the substrate.

5. A method as defined in claim 1, further comprising coupling an optoelectronic die to the waveguide.

6. A method as defined in claim 1, wherein fixing the waveguide to the substrate comprises fixing the waveguide within a trench formed in the second layer.

7. A method as defined in claim 6, wherein removing the at least the portion of the second layer comprises forming the trench.

8. A method of forming an alignment fiducial in a substrate, comprising:

providing a substrate having a metal layer;

forming an alignment fiducial in the metal layer; and

forming a dielectric layer over the metal layer to obscure the alignment fiducial.

9. A method as defined in claim 8, wherein forming the alignment fiducial comprises removing a portion of the metal layer.

10. A method as defined in claim 8, further comprising forming a trench in the dielectric layer over the alignment fiducial.

11. A method as defined in claim 10, wherein forming the trench comprises exposing the alignment fiducial.

12. A method as defined in claim 8, further comprising removing a portion of the dielectric layer to make the alignment fiducial visible.

13. A method as defined in claim 12, wherein the alignment fiducial is made visible through a remaining portion of the dielectric layer.

14. A method defined in claim 12, wherein removing the portion of the dielectric layer to expose the alignment fiducial comprises at least one of laser milling the portion of the dielectric layer or plasma etching the portion of the dielectric layer.

15. A substrate for use with an optoelectronic flip-chip assembly, comprising:

a substrate;

a metal layer on the substrate and having at least one alignment fiducial formed therein; and

a dielectric layer formed on the metal layer.

16. A substrate as defined in claim 15, wherein the alignment fiducial is obscured by the dielectric layer.

17. A substrate as defined in claim 15, wherein the alignment fiducial comprises at least one void in the metal layer.

18. A substrate as defined in claim 15, further comprising a trench formed in the dielectric layer over the alignment fiducial.

19. A substrate as defined in claim 15, wherein the alignment fiducial is visible through the dielectric layer via an aperture formed in the dielectric layer.

20. A substrate as defined in claim 15, wherein the alignment fiducial is visible through the dielectric layer via a recess formed in the dielectric layer having a depth that is less than a thickness of the dielectric layer.

21. An optoelectronic flip-chip assembly, comprising:

a substrate having a first layer and a second layer, the first layer including at least one alignment fiducial;

a waveguide aligned with the alignment fiducial and fixed to the substrate; and

an optoelectronic die having a first portion engaging the waveguide and a second portion flip-chip bonded to the substrate.

22. An assembly as defined in claim 21, wherein a portion of the second layer is removed to expose the alignment fiducial.

23. An assembly as defined in claim 21, wherein the second layer includes a trench and wherein the alignment fiducial is visible in the trench.

24. An assembly as defined in claim 21, wherein the alignment fiducial comprises at least one void in the first layer.

25. A system comprising the optoelectronic flip-chip assembly of claim 21 coupled to a telecommunication router.