Abstract: A detector for electromagnetic radiation such as millimeter wave and infrared employs a ring-shaped ferroelectric element having a temperature affected by an absorber for the radiation. The dielectric constant of the ferroelectric material is a strong function of the temperature near its Curie temperature. The resonant frequency of the ferroelectric element is detected by applying a swept-frequency signal to the circuit and detecting the frequency which enhances the energy of the pulse. A two-dimensional camera for the radiation employs a two-dimensional array of these ferroelectric resonant circuits and a system for rapidly interrogating their resonant frequencies on a sequential basis.

Abstract: A first preferred method for increasing the solderability of a substrate comprising: preparing the substrate for nickel plating by cleaning and removal of surface contaminants; plating a first nickel film of the desired thickness directly onto the substrate; preparing the nickel film comprising thoroughly cleaning the surface; depositing a substantially pure nickel film directly on the first nickel film using a suitable PVD technique; and applying solder to the substantially pure nickel film. Another preferred method for increasing the solderability of a substrate comprising plating a first nickel layer directly onto the substrate by using an electrolytic or electroless nickel plating process; depositing a substantially pure nickel film directly on the first nickel film using physical vapor deposition; and applying solder to the substantially pure nickel film.

Abstract: A detector for electromagnetic radiation such as millimeter wave and infrared employs a ring-shaped ferroelectric element having a temperature affected by an absorber for the radiation. The dielectric constant of the ferroelectric material is a strong function of the temperature near its Curie temperature. The resonant frequency of the ferroelectric element is detected by applying a swept-frequency signal to the circuit and detecting the frequency which enhances the energy of the pulse. A two-dimensional camera for the radiation employs a two-dimensional array of these ferroelectric resonant circuits and a system for rapidly interrogating their resonant frequencies on a sequential basis.

Abstract: A shadow mask for sputtering is formed from a single crystal silicon wafer which is mechanically and chemically polished to produce top and bottom surfaces which are substantially flat and parallel to one another. The wafer is provided with one or more pyramidal etch pits which are arranged in a pattern. Each pit has a substantially square cross-section on the top surface, and a smaller substantially square cross-section on the bottom surface to produce an aperture in the wafer. In use, the wafer is clamped against a flat substrate with its apertures opening toward the evaporant beam. After use, the deposited species may be cleaned from the wafer using suitable etchants which render the wafer unharmed, and therefore reusable.