Stress relief for electro-optical printed circuit board
AssigneeXyratex Technology Limited
InventorRichard C. A. Pitwon
Life of this patent
Estimating the term…
Abstract
Electro-optical circuit boards may include one or more recesses to provide stress relief between multiple layers of the electro-optical circuit boards during variations in applied temperature. The one or more recesses may be included in the substrate and/or the optical layer of the electro-optical circuit boards. The one or more recesses may also contain a compliant material disposed therein to improve the flexibility of the substrate and/or the optical layer. For example, the compliant material may disperse thermal expansion stress within the electro-optical circuit board.
Claims20
An electro-optical circuit board comprising:
- a first substrate and a second substrate extending along a longitudinal direction;
- an optical layer positioned between the first substrate and the second substrate and defining a first optical layer surface and a second optical layer surface opposing the first optical layer surface, the optical layer comprising:
- a cladding layer extending from the first optical layer surface to the second optical layer surface,
- one or more polymeric waveguide cores at least partially disposed within the cladding layer and extending along the longitudinal direction, and
- one or more optical layer recesses extending into the cladding layer from first optical layer surface or the second optical layer surface;
- and
- a compliant material disposed within the one or more optical layer recesses.
A system comprising:
- an electro-optical circuit board comprising:
- a substrate defining a first substrate surface and a second substrate surface opposing the first substrate surface,
- a cladding layer embedded within the substrate between the first substrate surface and the second substrate surface, the cladding layer defining a first cladding layer surface and a second cladding layer surface opposing the first cladding layer surface,
- one or more polymeric waveguide cores embedded within the cladding layer, and
- an expansion joint comprising a compliant material having a Young's modulus of less than 1 GPa and located in the cladding layer and extending into the first cladding layer surface or the second cladding layer surface, and a coefficient of thermal expansion of the substrate is at least 10 ×10−6/° C. different than a coefficient of thermal expansion of the cladding layer;
- and
- a storage device coupled to the electro-optical circuit board.
A method of reducing thermal expansion stress comprising:
- providing an electro-optical circuit board, the electro-optical circuit board comprising:
- a first substrate and a second substrate extending along a longitudinal direction,
- an optical layer positioned between the first substrate and the second substrate and defining a first optical layer surface and a second optical layer surface opposing the first optical layer surface, the optical layer comprising:
- a cladding layer extending from the first optical layer surface to the second optical layer surface,
- one or more polymeric waveguide cores at least partially disposed within the cladding layer and extending along the longitudinal direction, and
- one or more optical layer recesses extending into the cladding layer from the first optical layer surface or the second optical layer surface, and
- a compliant material having a Young's modulus of less than 1 GPa and disposed within the one or more optical layer recesses;
- heating the electro-optical circuit board to create thermal expansion stress within the optical layer;
- and
- dispersing the thermal expansion stress within the compliant material.
Dependencies are inferred from the claim text.