An insulator that supports a line from a pin includes a core that defines an opening configured to receive the pin, and includes a shell formed from a polymer disposed over an outer surface of the core. The insulator also includes a head formed from the core or the shell, and configured to support the line spaced from the pin.

Embodiments of the disclosure describe a method that includes disposing an electrical insulator material over a layer of a ceramic-based material having vias and solid portions between the vias. The vias are filled with an electrically conductive metal that forms electrical paths through the layer of the ceramic-based material. A composite structure is formed that includes portions of the electrical insulator material that are fixed to the solid portions of the layer of the ceramic-based material. The composite structure further includes regions positioned between the portions of the electrical insulator material. The electrical insulator material has a first coefficient of thermal expansion (CTE), the electrically conductive metal has a second CTE, and the ceramic-based material has a third CTE that is greater than the first CTE and less than the second CTE.