Stress relief for electro-optical printed circuit board

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.