Multi-layer ceramic feedthrough structure in a transmitter optical subassembly

A header assembly for use in an optical transceiver module, comprising:

• a base;
• a cap mechanically sealed to the base to define a hermetic enclosure;
• a multi-layer platform (“MLP”) hermetically passing through the base, the MLP having an interior portion located within the hermetic enclosure and an exterior portion located outside of the hermetic enclosure, the MLP including:
• a lower layer composed of insulative material;
• a first intermediate layer composed of an insulative material;
• a top sealing layer located atop a portion of the first intermediate layer, the top sealing layer being hermetically attached to a portion of the base;
• and
• at least one conductive pathway defined on at least one of the lower and first intermediate layers, the at least one conductive pathway having a terminal end on a surface of the exterior portion of the MLP and a terminal end on a portion of the interior portion.

A header assembly for use in an optical transceiver module, comprising:

• a hermetic enclosure formed by a metallic base and a cap mechanically attached to the base;
• a multi-layer platform (“MLP”) hermetically extending through the base to define an interior portion enclosed by the hermetic enclosure and an exterior portion located outside of the hermetic enclosure, the MLP including:
• an upper insulating layer;
• an intermediate layer having a top and bottom surface, the intermediate layer having a plurality of conductive features on its top surface, including:
• at least one conductive transmission line extending from the exterior portion to the interior portion of the MLP;
• at least one conductive ground signal line contact pad located on the exterior portion;
• at least one conductive intermediate layer general signal line contact pad located on the exterior portion;
• and
• at least one conductive intermediate layer general signal line portion, the at least one general signal line portion terminating at a contact pad on the interior portion;
• a lower layer having a top and bottom surface, the lower layer having a plurality of conductive features on its top surface, including:
• at least one conductive ground signal line portion that is electrically connected to the at least one ground signal line contact pad by at least one conductive via, the at least one ground signal line portion being aligned with the at least one transmission line on the intermediate layer;
• and
• at least one lower layer general signal line portion that is electrically connected to the at least one intermediate layer general signal line portion by a conductive via, the at least one lower layer general signal line portion also being electrically connected to the at least one intermediate layer general signal line contact pad by a conductive via.

30 A header assembly as defined in claim 29, wherein:

• the at least one ground signal line contact pad comprises four ground signal line contact pads;
• the at least one intermediate layer general signal line contact pad comprises three intermediate layer general signal line contact pads;
• the at least one intermediate layer general signal line portions comprises three intermediate layer general signal line portions;
• the at least one ground signal line portion comprises two ground signal line portions;
• and
• the at least one lower layer general signal line portion comprises three lower layer general signal line portions.

A header assembly for use in an optical transceiver module, comprising

• a hermetic enclosure formed by a metallic base and mechanically attached to the base;
• a multi-layer platform (“MLP”) hermetically extending through the base to define an interior portion enclosed by the hermetic enclosure and an exterior portion located outside of the hermetic enclosure, the MLP including:
• an upper insulating layer;
• an upper intermediate layer having a top and bottom surface, the upper intermediate layer having a plurality of conductive features on its top surface, including:
• at least one conductive transmission line structure extending from the exterior portion and terminating on the interior portion of the MLP, the at least one transmission line structure including a co-planar transmission line positioned between two ground signal line strips;
• at least one conductive upper intermediate layer general signal line extending between the exterior portion and the interior portion of the MLP;
• and
• at least one conductive signal line contact pad positioned on the exterior portion of the MLP;
• a lower intermediate layer having a plurality of conductive features, including:
• a top surface having at least one conductive ground signal line portion that is electrically connected to the ground signal line strips on the upper intermediate layer by at least one conductive via, the at least one ground signal line portion being aligned with the at least one transmission line structure on the upper intermediate layer;
• a bottom surface having at least one cooling device signal line portion extending from the exterior portion to the interior portion of the MLP, the at least one cooling device signal line portion being electrically connected to the at least one cooling device signal line contact pad on the upper intermediate layer by at least one conductive via that is defined through the upper and lower intermediate layers;
• and
• a lower layer having a bottom surface substantially covered by a conductive material;
• and
• a TEC positioned within the hermetic enclosure to electrically connect to the at least one cooling device signal line portion on the bottom surface of the lower intermediate layer.

An optical transceiver module for use in optical communications networks, comprising:

• a housing containing:
• a printed circuit board;
• a receiver optical subassembly (“ROSA”);
• and
• a transmitter optical subassembly (“TOSA”), the TOSA including:
• an outer casing;
• a receptacle attached at a first end of the outer casing;
• and
• a header assembly attached at a second end of the outer casing, the header assembly comprising:
• a base;
• a cap mechanically sealed to the base to define a hermetic enclosure;
• a multi layer platform (“MLP”) hermetically passing through the base, the MLP having an interior portion located within the hermetic enclosure and an exterior portion located outside of the hermetic enclosure, the MLP including:
• a lower layer composed of insulative material;
• a first intermediate layer composed of an insulative material;
• a top sealing layer located atop a portion of the first intermediate layer, the top sealing layer being hermetically attached to a portion of the base;
• and
• at least one conductive pathway defined on at least one of the lower layer and first intermediate layer, the at least one conductive pathway having a terminal end on a surface of the exterior portion of the MLP and a terminal end on a portion of the interior portion.