Heat-Bonded Laminates of Aluminum Foil and Flexible Dielectric Materials

Selected properties of thermal impulse-bonded laminates, made from polyethylene film and flexible glass ribbon, respectively, bonded to aluminum foil without an adhesive, are investigated as functions of the temperature, pressure, and duration of the bonding process. For the glass/metal laminates a combination of low-temperature (relative to the softening point), low-pressure, and long-time bonding produces the highest yields in dielectric breakdown and in hermeticity tests. For the plastic/metal laminates maximum peel bond strength is achieved with high-temperature (relative to the melting range) high-pressure bonding, with dielectric strength being somewhat below the potential maximum. In order to optimize these properties, the volume of air and other gases entrapped, adsorbed, and occluded in the interfaces and within the dielectric must be minimized in the bonding process, especially near the edges of the laminates.