Electronic devices may include electronic device structures such substrates, structures with cavities, and housing structures. Tape may be used to seal components to the surface of a substrate or within a cavity. The tape may have a nonstick polymer layer such as a layer of parylene and one or two layers of adhesive. The nonstick layer may be formed in a pattern so that some of the layer of adhesive is uncovered by the nonstick layer. The nonstick layer may be oriented so that the adhesive is interposed between the nonstick layer and a sealed component or may be oriented so that the nonstick layer is interposed between the adhesive layer and the sealed component. The component that is sealed by the tape may be an electrical component such as a dome switch or other mechanical or electrical component.