Optoelectronic modules that have shielding to reduce light leakage or stray light, and fabrication methods for such modules
View Patent ↗Optoelectronic modules include an optoelectronic device and a transparent cover. A non-transparent material is provided on the sidewalls of the transparent cover, which can help reduce light leakage from the sides of the transparent cover or can help reduce stray light from entering the module. The modules can be fabricated, for example, in wafer-level processes. In some implementations, openings such as trenches are formed in a transparent wafer. The trenches then can be filled with a non-transparent material using, for example, a vacuum injection tool. When a wafer-stack including the trench-filled transparent wafer subsequently is separated into individual modules, the result is that each module can include a transparent cover having sidewalls that are covered by the non-transparent material.
1. A method of fabricating optoelectronic modules each of which includes at least one optoelectronic device and at least one an optical element, the method comprising:
providing a transparent wafer having first and second surfaces on opposite sides of the transparent wafer, wherein there are a plurality of non-transparent spacer elements on one of the surfaces of the transparent wafer;
forming openings in the transparent wafer, each opening disposed over a respective one of the spacer elements and extending through the transparent wafer; and
substantially filling the openings in the transparent wafer with a material that is non-transparent to light emitted by or detectable by the optoelectronic device.
2. The method of claim 1 further including:
attaching a substrate wafer to the spacer elements such that the spacer elements separate the substrate wafer from the transparent wafer, wherein there are a plurality of optoelectronic devices mounted on the substrate wafer, and wherein the substrate wafer and the transparent wafer form a wafer stack; and
separating the wafer stack into a plurality of individual modules, wherein each module includes at least one of the optoelectronic devices substantially aligned with a corresponding optical element that is on a portion of the transparent wafer that has sidewalls covered by the non-transparent material.
3. The method of claim 1 further including:
attaching singulated optoelectronic devices to the spacer elements such that the spacer elements separate the singulated optoelectronic devices from the transparent wafer, wherein the singulated optoelectronic devices and the transparent wafer form a vertical stack; and
separating the vertical stack into a plurality of individual modules, wherein each module includes at least one of the singulated optoelectronic devices substantially aligned with a corresponding optical element that is on a portion of the transparent wafer that has sidewalls covered by the non-transparent material.
4. The method of claim 1 wherein the optical elements are formed and the opening are filled using a single combined replication and vacuum injection tool.
5. The method of claim 1 wherein the openings are formed by dicing, micromachining or laser cutting.
6. The method of claim 1 wherein each of the openings extends partially into a respective one of the spacers elements.
7. The method of claim 1 wherein providing a transparent wafer includes providing a transparent wafer having optical elements on at least one of the first or second surfaces.
8. The method of claim 1 wherein providing a transparent wafer includes providing a transparent wafer having optical elements on the same surface of the transparent wafer as the spacer elements.
9. The method of claim 1 further including partially covering the first surface of the transparent wafer with the same non-transparent material that fills the openings in the transparent wafer, wherein the first surface is on the opposite side of the transparent wafer from the surface on which the spacer elements are disposed,
and wherein when the wafer stack is separated into individual modules, each module includes a baffle composed of the non-transparent material.
10. The method of claim 1 further including attaching a baffle wafer over the filled-in openings in the transparent wafer, the baffle wafer being composed of material that is non-transparent to light emitted by or detectable by the optoelectronic device.
11. The method of claim 1 wherein the spacer elements are composed of the same non-transparent material as the material that fills the openings in the transparent wafer.
12. The method of claim 1 including forming optical elements on the opposite surface of the transparent wafer from the surface on which the spacer elements are disposed, wherein a single replication and vacuum injection tool is used to form the optical elements and to fill the openings in the transparent wafer with a non-transparent material.
13. The method of claim 1 wherein there is at least one of a focal length correction layer or an optical filter on a surface of the transparent wafer, the method further including:
attaching one or more optics assemblies over an object-side of the transparent wafer, wherein the one or more optics assemblies include lens stacks.
14. The method of claim 1 wherein the openings are filled with a non-transparent material using a vacuum injection tool.
15. The method of claim 14 further including causing the non-transparent material to harden.
16. The method of claim 1 further including forming optical elements on the opposite surface of the transparent wafer from the surface on which the spacer elements are disposed.
17. The method of claim 16 wherein the optical elements are formed by an embossing-type replication technique.
18. A method of fabricating optoelectronic modules each of which includes at least one optoelectronic device and at least one optical element, the method comprising:
providing a transparent wafer having first and second surfaces on opposite sides of the transparent wafer, wherein there are a plurality of non-transparent spacer elements on one of the surfaces of the transparent wafer;
forming openings in the transparent wafer, each opening disposed over a respective one of the spacer elements and extending through the transparent wafer; and
providing a material that is non-transparent to light emitted by or detectable by the optoelectronic devices in the openings of the transparent wafer so as to cover sidewalls of portions of the transparent wafer.