A method for underfilling and encapsulating flip-chip configured semiconductor devices mounted on a carrier substrate using stereolithography to form, in situ, at least semisolid dam structures of photopolymeric material about the devices to entrap liquid, unpolymerized resin between the devices and substrate is disclosed. The sensor unit includes a housing having an inner end within the window frame, an outer end at a surface of the window frame and a flexible wave wire antenna extending e. The material of said recording layer comprises a component that is generating an etchant. Alternatively, the wound dressing may allow fluid to pass through the suction member.