A microcavity structure. In an illustrative embodiment, the microcavity structure includes a first substrate, which has a region of interest. A second substrate with a perforation therein is bonded to the first substrate. The perforation coincides with the region of interest. In a specific embodiment, the first substrate is implemented via a Printed Circuit Board (PCB). The region of interest includes one or more circuit components, including an actuator, such as a bridgewire, thereon or therein. A smoothing layer is included between the PCB and the actuator. A bonding gasket adheres the first substrate to the second substrate. The perforation accommodates energetic material that is selectively ignited via the actuator.