In a structural cold plate, typically there is a structural member such as a honeycomb panel or a brazed sandwich assembly that provides the structural strength, and at least one cold plate that cools equipment attached to the structural member. The cold plate is typically located between the structural member and the item it is cooling. With this configuration, the cold plate’s location, shape, and size are limited to being placed beneath the item it is cooling. This requires an additional envelope that is equal to the cold plate thickness. Being able to locate the cold plate in locations other than beneath the item it is cooling would have multiple benefits including reduced envelope requirements in the direction of the item it is cooling, as well as allowing a larger cold plate cooling footprint.
By replacing the outer layer of the structural member—whether the face sheet of a honeycomb panel, the end sheets of a brazed structural sandwich assembly, or some other built up structure—with a thermal heat spreader, such as an annealed pyrolytic graphite (APG) sheet, the cold plate can be placed adjacent to the item being cooled, rather than directly beneath it. With this configuration, the size, shape, and location of the cold plate can be adjusted as needed. Proceeding this way will reduce the overall height of the assembly since the cold plate no longer needs to be placed between the structural member and the item it is cooling. Second, it allows the size of the cold plate to be adjusted to whatever size and shape is needed, and it allows it to be located in any convenient location.
Although work has been done with heat spreaders on structural members, typically they are either bonded on top of the structure or placed in machined pockets of the top surface of the structural member. This configuration is believed to be unique in that the thermal heat spreader is made to be an integral part of the structural member.