Siliconized heterogeneous optical engine
A siliconized heterogeneous optical engine. In some embodiments, the siliconized heterogeneous optical engine includes a photonic integrated circuit; an electro-optical chip, on a top surface of the photonic integrated circuit; an electronic integrated circuit, on the top surface of the photonic integrated circuit; an interposer, on the top surface of the photonic integrated circuit; a redistribution layer, on a top surface of the interposer, the redistribution layer including a plurality of conductive traces; and a plurality of protruding conductors, on the conductive traces of the redistribution layer. The electronic integrated circuit may be electrically connected to the electro-optical chip and to a conductive trace of the plurality of conductive traces of the redistribution layer.
1. A system, comprising:
a photonic integrated circuit (PIC) having a top surface, a cavity in the top surface of the PIC, and a V-groove in the top surface of the PIC;
an electro-optical chip in the cavity in the top surface of the PIC;
an optical fiber in the V-groove, a first waveguide in the PIC forming an optical connection between the optical fiber and a second waveguide in the electro-optical chip, and the cavity in the top surface of the PIC being configured to vertically align the second waveguide in the electro-optical chip with the first waveguide in the PIC;
an electronic integrated circuit, bonded to the top surface of the PIC by a first layer of epoxy;
an interposer, bonded to, and being positioned entirely above, the top surface of the PIC by a second layer of epoxy separated from the first layer of epoxy, the interposer being spaced apart on the top surface of the PIC from the electronic integrated circuit and from the electro-optical chip;
a redistribution layer, on a top surface of the interposer, the redistribution layer comprising a plurality of conductive traces; and
a plurality of protruding conductors, on the conductive traces of the redistribution layer and configured to attach to a digital integrated circuit,
the electronic integrated circuit being positioned entirely above the PIC and entirely between the electro-optical chip and the interposer, a height of the top surface of the electronic integrated circuit from the top surface of the PIC being less than a height of the top surface of the interposer from the top surface of the PIC,
the electronic integrated circuit being electrically connected to the electro-optical chip along a first electrical path that extends through a first conductive trace on the PIC and a wire bond that extends between the first conductive trace and the top surface of the electronic integrated circuit, a height of the wire bond from the top surface of the PIC being greater than the height of the top surface of the electronic integrated circuit from the top surface of the PIC,
the electronic integrated circuit being electrically connected to a second conductive trace of the plurality of conductive traces of the redistribution layer along a second electrical path separate from the first electrical path, the second electrical path extending through a standoff stitch bond that extends from the top surface of the electronic integrated circuit to the second conductive trace, a height of the standoff stich bond from the top surface of the PIC being greater than the height of the top surface of the interposer from the top surface of the PIC,
wherein the system further comprises a lid enclosing the electro-optical chip, the wire bond, only a portion of the PIC, and only a portion of the electronic integrated circuit, the standoff stitch bond being outside of the lid, and
wherein:
the electro-optical chip comprises an optical modulator configured to convert unmodulated light into light modulated with data, and the electronic integrated circuit comprises a driver circuit configured to drive the optical modulator; or
the electro-optical chip comprises a photodetector, and the electronic integrated circuit comprises a transimpedance amplifier connected to the photodetector.
2. The system of claim 1 , wherein the interposer is composed of silicon.
3. The system of claim 2 , wherein the interposer comprises an upper surface passivation layer composed of silicon dioxide.
4. The system of claim 1 , wherein one of the protruding conductors comprises:
a copper post, and
a gold ball on the copper post.
5. The system of claim 4 , wherein the gold ball is secured to the copper post with solder.
6. The system of claim 1 , wherein the interposer is composed of an organic compound or a ceramic compound.
7. The system of claim 6 , wherein one of the protruding conductors comprises a gold ball on the redistribution layer.
8. The system of claim 7 , wherein the gold ball is secured to the redistribution layer with solder.
9. The system of claim 6 , wherein one of the protruding conductors comprises:
a solder ball, and
a gold ball on the solder ball.
10. The system of claim 1 , wherein the interposer has a thickness of between 50 microns and 500 microns.
11. The system of claim 1 , wherein the electro-optical chip has a top surface at a height, above the top surface of the photonic integrated circuit, of less than 200 microns.
12. The system of claim 1 , wherein the wire bond extends to a height of at most 100 microns above the top surface of the electro-optical chip.
13. The system of claim 1 , wherein the standoff stitch bond extends to a height of at most 50 microns above the top surface of the interposer.