US 2025/0060545 A1Published application

Method and structure for shielding electromagnetic inteference in photonic integrated circuits stacked up electronic integrated circuits

AssigneeAvago Technologies International Sales Pte. Limited

InventorsVenkatesh Seetharam, Mike John Brosnan

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Abstract

Method and structure for shielding electromagnetic interference in photonic integrated circuits (PIC) disposed on electronic integrated circuits (EIC). The invention addresses the electromagnetic interference problem by employing vias through the PIC's bulk silicon substrate. The invention also uses a conductive layer covering the backside of the PIC bulk silicon substrate on which the metal heat spreader can be placed. Now, the vias can make electrical contact from the reference net formed for PIC's light transmission component on one or more metal layers of the PIC to the conductive layer on the backside of the PIC. Such an arrangement allows for robust electrical connection and allows the metal heat spreader to act as robust ground thus terminating the electromagnetic fields.

Claims20

Dependent claims

An integrated circuit device comprising:

a printed circuit board (PCB);
a first circuit on a first substrate comprising a first surface and a second surface, the first surface being coupled to the PCB, the second surface comprising a first plurality of contacts coupled to the first circuit;
a second circuit on a second substrate comprising a third surface and a fourth surface, the second circuit being disposed on the first circuit, the second circuit comprising at least a first component and a second component, the third surface comprising a second plurality of contacts coupled to the first component and the second component, the second plurality of contacts being coupled to the first plurality of contacts;
a layer of conductive material disposed on the fourth surface;
a metal layer disposed in a dielectric between the first component and the third surface;
a first plurality of vias extended from the fourth surface through the second substrate to at least partially surround the first component, the first plurality of vias being coupled to the layer of conductive material and the metal layer;
and
a second plurality of vias extended from the fourth surface through the second substrate to at least partially surround the second component, the second plurality of vias being coupled to the layer of conductive material and the metal layer.

5 more elements

A method for suppressing electrical coupling in a photonics integrated circuit, the method comprising:

providing a substrate comprising a first surface and the second surface, the second surface being opposite to the first surface;
packaging a first photonic component and a second photonic component on the first surface, the first photonic component comprising at least a light transmitter, the second photonic component comprising at least a light detector;
forming an electrical reference net based on at least one metal layer positioned in a dielectric, the dielectric at least partially covering the light transmitter and the light detector;
forming a first plurality of vias through the substrate from the second surface to couple to the electrical reference net, the first plurality of vias being disposed to at least partially surround the light transmitter;
and
forming a conductive layer on the second surface of the substrate, the conductive layer being coupled to the first plurality of vias and the electrical reference net to form an electrical shield for the first photonic component.

3 more elements

A photonics integrated device with electromagnetic shielding comprising:

a substrate with a first surface and a second surface, the second surface being opposite to the first surface;
a circuit formed on the first surface, the circuit comprising at least a first component and a second component, the first component comprising at least a light transmitter, the second component comprising at least a light detector;
a metal layer disposed in a dielectric on the first surface, the metal layer being an electrical reference with a grounded connection;
a first plurality of vias from the second surface through the substrate, the first plurality of vias being configured to couple to the electrical reference and to at least partially surround the first component;
a second plurality of vias from the second surface through the substrate, the second plurality of vias being configured to couple to the electrical reference and to at least partially surround the second component;
and
a conductive layer disposed on the second surface of the substrate, the conductive layer being coupled to the first plurality of vias and the second plurality of vias to form a first electromagnetic shield and a second electromagnetic shield respectively for the first component and the second component.

4 more elements

Dependencies are inferred from the claim text.