OPTOELECTRONIC ASSEMBLY AND METHOD OF MAKING THE SAME

• US 20020034834A1
• Filed: 06/15/1999
• Published: 03/21/2002
• Est. Priority Date: 01/06/1998
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Jean-Marc Verdiell
• Inventors: VERDIELL, JEAN-MARC
• Granted Patent: US 6,376,268 B1
• Time in patent office: Days
• US Class Current: 438/22
• 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 6/4208 using non-reciprocal elements or birefringent plates, i.e. quasi-isolators optical isolators per se G02F1/093, G02F1/0955
• CPC Class Codes: G02B 6/423 using guiding surfaces for the alignment
• CPC Class Codes: G02B 6/4244 Mounting of the optical elements
• CPC Class Codes: G02B 6/4245 Mounting of the opto-electronic elements
• CPC Class Codes: G02B 6/4267 Reduction of thermal stress, e.g. by selecting thermal coefficient of materials
• CPC Class Codes: G02B 6/4268 Cooling of semiconductor devices H01L23/24; of electric apparatus H05K7/20; of instruments G12B15/00
• 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 6/4274 Electrical aspects G02B6/4263 and G02B6/4265 take precedence
• CPC Class Codes: H01L 2224/48091 Arched
• 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

Abstract

An optoelectronic assembly having an insulating substrate with a planar surface and a metal layer bonded to the planar surface such that selected regions of the substrate are exposed and a step is produced between the substrate and a top surface of the metal layer. An active optical device is mounted on the metal layer and a passive optical device is aligned with the active device using the step as a fiduciary for positioning the former. The metal layer provides an electrical path to the active device. The thickness of the metal layer is selected such that the heat generated by the active device is dissipated, the substrate does not interfere with the propagation of light along the first optical axis, and such that the in-plane coefficient of thermal expansion (CTE) of the metal layer is constrained by the substrate. The optoelectronic assembly is also suitable for mounting active devices provided with submounts or without.

Claims

1. An optoelectronic assembly comprising:

a) an active optical device having a first optical axis;

b) an insulating substrate with a planar surface;

c) a metal layer bonded to said planar surface such that selected regions of said insulating substrate are exposed and a step is produced between said insulating substrate and a top surface of said metal layer, said active optical device being mounted on said metal layer such that said first optical axis is parallel to said insulating substrate, said metal layer further providing an electrical path to said active optical device and having a predetermined thickness such that;

i) heat generated by said active optical device is dissipated;

ii) said insulating substrate does not interfere with the propagation of light along said first optical axis; and

iii) the in-plane coefficient of thermal expansion (CTE) of said metal layer is constrained by said insulating substrate.

2. The optoelectronic assembly of claim 1 wherein said active optical device is selected from the group consisting of diode lasers, optical amplifiers, optical modulators, optical switches, optical fibers, and light detectors.

3. The optoelectronic assembly of claim 1 further comprising a first passive optical element having a second optical axis and being positioned in one of said selected regions such that said second optical axis is aligned with said first optical axis.

4. The optoelectronic assembly of claim 3 wherein said passive optical element is selected from the group consisting of optical fibers, lenses, filters, diffraction gratings, beam splitters, isolators, and mirrors.

5. The optoelectronic assembly of claim 3 wherein said passive optical element is positioned on said insulating substrate.

6. The optoelectronic assembly of claim 5 wherein said passive optical element has a flat bottom.

7. The optoelectronic assembly of claim 3 wherein said metal layer is patterned such that said step is a fiduciary for aligning said passive optical element.

8. The optoelectronic assembly of claim 7 wherein said passive optical element has a flat side wall fitting against said fiduciary.

9. The optoelectronic assembly of claim 1 wherein said metal layer is patterned as an electrical circuit.

10. The optoelectronic assembly of claim 9 further comprising electrical components mounted on said metal layer.

11. The optoelectronic assembly of claim 1 wherein said predetermined thickness ranges between 50 μ

m and 1,000 μ

m.

12. The optoelectronic assembly of claim 1 wherein said metal layer is made of a material selected from the group consisting of copper, copper-tungsten, copper alloys, copper composites, copper plated materials, copper clad materials and copper laminates.

13. The optoelectronic assembly of claim 1 wherein said insulating substrate is a ceramic chosen from the group consisting of alumina, BeO and AlN.

14. The optoelectronic assembly of claim 1 further comprising a bottom metal layer bonded to said insulating substrate opposite said planar surface.

15. The optoelectronic assembly of claim 14 wherein said bottom metal layer is patterned as an electrical circuit.

16. The optoelectronic assembly of claim 14 further comprising a cooling means.

17. The optoelectronic assembly of claim 16 wherein said bottom metal layer is patterned and covered with a cover to provide channels for a liquid coolant.

19. The method of claim 18 wherein said active optical device is selected from the group consisting of diode lasers, optical amplifiers, optical modulators, optical switches, optical fibers, and light detectors.

20. The method of claim 18 further comprising the step of positioning a first passive optical element having a second optical axis in one of said selected regions such that said second optical axis is aligned with said first optical axis.

21. The method of claim 18 further comprising the step of patterning said metal layer.

22. The method of claim 18 wherein said metal layer is made of a material selected from the group consisting of copper, copper-tungsten, copper alloys, copper composites, copper plated materials, copper clad materials, and copper laminates.

23. The method of claim 18 wherein said insulating substrate is selected from ceramics from the group consisting of alumina, BeO and AlN.

24. The method of claim 18 further comprising the step of forming said metal layer by a process selected from the group consisting of photolithography, etching, stamping, brazing, electrodeposition, and electro-discharge machining (EDM) before said bonding step.

25. The method of claim 18 further comprising the step of forming said metal layer by a process selected from the group consisting of photolithography and diamond sawing after said bonding step.

26. The method of claim 18 further comprising the step of polishing said metal layer to said predetermined thickness.

27. The method of claim 18 further comprising the step of etching said metal layer to said predetermined thickness.

28. The method of claim 18 further comprising the step of placing a passive optical element having a second optical axis in one of said selected regions such that said second optical axis is aligned with said first optical axis.

29. The method of claim 28 wherein said placing step includes actively displacing said passive optical element in one of said selected regions.

30. The method of claim 28 wherein said placing step includes displacing said passive optical element with said step serving as a fiduciary along which said passive optical element is displaced.

56. The optoelectronic assembly of claim 5,1 further comprising a bottom metal layer bonded to said insulating substrate opposite said planar surface.

18. A method of making an optoelectronic assembly comprising the following steps:

a) selecting an insulating substrate with a planar surface;

b) bonding a metal layer to said planar surface such that selected regions of said insulating substrate are exposed and a step is produced between said insulating substrate and a top surface of said metal layer;

c) mounting an active optical device having a first optical axis on said metal layer such that said first optical axis is parallel to said insulating substrate, and such that said metal layer provides an electrical path to said active optical device;

d) selecting a predetermined thickness for said metal layer such that;

i) heat generated by said active optical device is dissipated;

ii) said insulating substrate does not interfere with the propagation of light along said first optical axis; and

iii) the in-plane coefficient of thermal expansion (CTE) of said metal layer is constrained by said insulating substrate.

31. A method of making at least two optoelectronic assemblies comprising the following steps:

a) selecting an insulating substrate with a planar surface;

b) bonding at least a first and second metal layers to said planar surface such that selected regions of said insulating substrate are exposed and steps are produced between said insulating substrate and top surfaces of said metal layers;

c) mounting active optical devices each having first optical axes on said metal layers such that said first optical axes are parallel to said insulating substrate, and such that said metal layers provide electrical paths to said active optical devices;

d) selecting a predetermined thickness for said metal layers such that;

i) heat generated by said active optical devices is dissipated;

ii) said insulating substrate does not interfere with the propagation of light along said first optical axes;

iii) the in-plane coefficient of thermal expansion (CTE) of said metal layers is constrained by said insulating substrate; and

e) dividing said insulating substrate into at least a first and second parts, each of said parts including one of said metal layers.

32. The method of claim 31 further comprising the step of forming said metal layers by a process selected from the group consisting of photolithography, etching, stamping, brazing, electrodeposition and electro-discharge machining before said bonding step.

33. The method of claim 31 further comprising the step of forming said metal layers by a process selected from the group consisting of photolithography, etching and diamond sawing after said bonding step.

34. The method of claim 31 wherein said bonding step is performed after said dividing step.

35. The method of claim 31 further comprising the step of placing passive optical elements in said selected regions.

36. The method of claim 35 wherein said placing step is performed before said dividing step.

37. The method of claim 35 wherein said placing step is performed after said dividing step.

39. The optoelectronic assembly of claim 38 wherein said first active optical device is selected from the group consisting of diode lasers, optical amplifiers, optical modulators, optical switches, optical fibers, and light detectors.

40. The optoelectronic assembly of claim 38 further comprising a first passive optical element having a second optical axis and being positioned in one of said selected regions such that said second optical axis is aligned with said first optical axis.

41. The optoelectronic assembly of claim 40 wherein said passive optical element is positioned on said insulating substrate.

42. The optoelectronic assembly of claim 38 further comprising a second active optical device having a third optical axis and being mounted on said metal layer such that said third optical axis is aligned with said first optical axis.

43. The optoelectronic assembly of claim 38 wherein said predetermined thickness ranges between 50 μ

m and 1,000 μ

m.

38. An optoelectronic assembly comprising:

a) an insulating substrate with a planar surface;

b) a metal layer bonded to said planar surface such that selected regions of said insulating substrate are exposed and a step is produced between said insulating substrate and a top surface of said metal layer;

c) a first active optical device on a submount, said first active optical device having a first optical axis, said submount being positioned on said insulating substrate where said step is a fiduciary for aligning said first active optical device such that said first optical axis is parallel to said insulating substrate, said submount further providing an electrical path to said first active optical device and having a predetermined thickness such that;

i) heat generated by said first active optical device is dissipated through said submount; and

ii) said insulating substrate does not interfere with the propagation of light along said first optical axis.

44. A method of making an optoelectronic assembly comprising the following steps:

a) selecting an insulating substrate with a planar surface;

b) bonding a metal layer to said planar surface such that selected regions of said insulating substrate are exposed and a step is produced between said insulating substrate and a top surface of said metal layer;

c) placing a first active optical device having a first optical axis on a submount;

d) positioning said submount on said insulating substrate where said step is a fiduciary for aligning said first active optical device such that said first optical axis is parallel to said insulating substrate, said submount further providing an electrical path to said first active optical device and having a predetermined thickness such that;

i) heat generated by said first active optical device is dissipated through said submount; and

ii) said insulating substrate does not interfere with the propagation of light along said first optical axis.

45. The optoelectronic assembly of claim 44 wherein said first active optical device is selected from the group consisting of diode lasers, optical amplifiers, optical modulators, optical switches, optical fibers, and light detectors.

46. The optoelectronic assembly of claim 44 further comprising a first passive optical element having a second optical axis and being positioned in one of said selected regions such that said second optical axis is aligned with said first optical axis.

47. The optoelectronic assembly of claim 46 wherein said passive optical element is positioned on said insulating substrate.

48. The optoelectronic assembly of claim 44 further comprising a second active optical device having a third optical axis and being mounted on said metal layer such that said third optical axis is aligned with said first optical axis.

49. The optoelectronic assembly of claim 44 wherein said predetermined thickness ranges between 50 μ

m and 1,000 μ

m.

50. A method of making an optoelectronic assembly comprising the following steps:

a) selecting an insulating substrate with a planar surface;

b) bonding a metal layer to said planar surface such that selected regions of said insulating substrate are exposed and a step is produced between said insulating substrate and a top surface of said metal layer;

c) providing said planar surface with a metalization;

d) positioning an active optical device having a first optical axis on said metalization of said insulating substrate where said step is a fiduciary for aligning said active optical device such that said first optical axis is parallel to said insulating substrate, said metalization further providing an electrical path to said active optical device.

51. An optoelectronic assembly comprising:

a) an active optical device with an edge;

b) an insulating substrate with a planar surface and with an edge;

c) a metal layer with an edge;

wherein said metal layer is bonded to said planar surface such that said metal layer edge is flush with said insulating substrate edge, and said active optical device edge is flush with said metal layer edge, said metal layer further providing an electrical path to said active optical device and having a predetermined thickness such that;

1) heat generated by said active optical device is dissipated;

2) said insulating substrate does not interfere with the propagation of light along said first optical axis; and

3) the in-plane coefficient of thermal expansion (CTE) of said metal layer is constrained by said insulating substrate.

52. The optoelectronic assembly of claim 51 wherein said active optical device is selected from the group consisting of diode lasers, optical amplifiers, optical modulators, optical switches, optical fibers, and light detectors.

53. The optoelectronic assembly of claim 51 wherein said predetermined thickness ranges between 50 μ

m and 1,000 μ

m.

54. The optoelectronic assembly of claim 51 wherein said metal layer is made of a material selected from the group consisting of copper, copper-tungsten, copper alloys, copper composites, copper plated materials, copper clad materials and copper laminates.

55. The optoelectronic assembly of claim 51 wherein said insulating substrate is selected from ceramics from the group consisting of alumina, BeO and AlN.