Optoelectronic modules having features for improved alignment and reduced tilt

1. An optoelectronic module comprising:

an electrically conductive trace;

an optoelectronic device mounted on the electrically conductive trace and being operable to emit or detect light;

an optical element having a mask disposed over the optoelectronic device;

an optical sub-assembly disposed over the optical element;

a first spacer in direct contact with an upper surface of the optical element, the first spacer establishing a distance between the optical element and the optical sub-assembly;

a second spacer that supports the optical element, the second spacer being in direct contact with an upper surface of the trace and establishing a distance between the trace and the optical element;

wherein the first and second spacers are attached to one another by adhesive, and

the optical element is disposed within a recess in the second spacer and is supported by direct contact with surfaces of the second spacer.

2. The optoelectronic module of claim 1 having flat surfaces at corners of the recess in which the optical element is disposed, an underside of the optical element being in direct contact with the flat surfaces which support the optical element.

3. The optoelectronic module of claim 2 including recessed pockets containing adhesive in contact with the underside of the optical element, the recessed pockets being adjacent the flat surfaces.

4. The optoelectronic module of claim 3 wherein portions of the recessed pockets are not filled with adhesive and provide venting channels to allow gas in a chamber over the optoelectronic device to escape.

5. The optoelectronic module of claim 1 comprising a second wafer having a cutout region extending there through, at least part of the cutout region being located directly above an alignment mark on an upper surface of the trace or on an upper surface of the optoelectronic device.

6. The optoelectronic module of claim 1 comprising a second wafer having a cutout region extending there through, at least part of the cutout region being located directly below an alignment mark on the optical element.

7. The optoelectronic module of claim 1 wherein the mask comprises a black chrome pattern on a transparent substrate.

8. The optoelectronic module of claim 1 further including a flex cable, wherein a portion of the second spacer is undercut to receive the flex cable, which is connected electrically to the electrically conductive trace.

9. The optoelectronic module of claim 8 further including a substrate on which the electrically conductive trace is mounted, wherein the electrically conductive trace defines channels that separate different parts of the trace electrically from one another, the channels containing adhesive that fixes the second spacer to the substrate.

10. The optoelectronic module of claim 9 wherein portions of the channels defined by the electrically conductive trace extend under the flex cable, and wherein the portions of the channels extending under the flex cable are not filled with adhesive.

11. A method of manufacturing an optoelectronic module, the method comprising:

providing an assembly comprising:

an optical element having a mask;

an optical sub-assembly disposed over the optical element;

a first spacer in direct contact with an upper surface of the optical element, the first spacer establishing a distance between the optical element and the optical sub-assembly;

a second spacer that supports the optical element, wherein the first and second spacers are attached to one another by adhesive, and the optical element is disposed within a recess in the second spacer and is supported by direct contact with surfaces of the second spacer;

performing optical testing of the assembly; and

attaching the assembly to a sub-assembly that comprises an optoelectronic device mounted on an electrically conductive trace, wherein the optoelectronic device is operable to emit or detect light, and the electrically conductive trace is on an electrically insulating substrate, wherein attaching the assembly to the sub-assembly includes:

bringing alignment surfaces of the second spacer into direct contact with an upper surface of the electrically conductive trace; and

attaching the second spacer to the substrate by adhesive.

12. The method of claim 11 wherein bringing alignment surfaces of the second spacer into direct contact with the upper surface of the electrically conductive trace establishes a distance between the electrically conductive trace and the optical element.

13. The method of claim 11 wherein providing the assembly includes:

bringing the alignment surfaces of the first spacer into direct contact with the upper surface of the optical element; and

attaching the first spacer to the second spacer using adhesive.

14. The method of claim 11 wherein the optical testing of the assembly is performed prior to attaching the assembly to a sub-assembly.

15. The method of claim 14 wherein performing optical testing of the assembly includes emitting light through the optical element and the optical sub-assembly and evaluating optical performance of the assembly.

16. The method of claim 11 wherein the second spacer has flat surfaces at corners of the recess in which the optical element is disposed, and wherein providing the assembly includes:

placing the optical element that includes the mask onto the flat surfaces such that an underside of the optical element is in direct contact with the flat surfaces to support the optical element.

17. The method of claim 16 wherein the second spacer has recessed pockets adjacent the flat surfaces, the method further including:

providing adhesive in the recessed pockets prior to placing the optical element onto the flat surfaces; and

subsequently fixing the optical element in place within the recess of the second spacer via the adhesive.