Abstract: An aqueous acidic composition suitable for etching which contains an acid and a thiourea compound, and use thereof.

Abstract: A polysulfone base stop resist material to protect gold thermocompression bonding sites on a circuit module during a solder dipping operation. Along with the thermoplastic, thermostable strippable base of polysulfone, the resist includes a solvent for the polysulfone and a filler which holds the melted polysulfone in place during the solder dipping operation.

Abstract: Lightweight electrodes and their method of manufacture for disposition in an electrochemical cell are described. The electrodes comprise a catalytic layer made up of a substantially uniform admixture of metal containing electrocatalyst particles and a fluorocarbon polymer. The manufacture is such that an open pore structure is obtained having porosity sufficient to permit diffusion of gases into the catalytic layer. There is further described electrolytes comprising an eutectic mixture of at least two alkali metal hydroxides substantially free of water and electrolytes which are mobile and have a pastelike consistency at a temperature below about 300.degree. C.