Abstract: To form a sturdy, environmentally essentially unaffected and high-temperature resistance electrical connection between a connection wire (4) and a conductive track (2) on the substrate (1), a portion of the wire (4) is embedded in a unitary bonding element (3). The bonding element comprises about 70% of metal particles and 30% of glass particles to form a bonding spot. The bonding spot is made by applying a paste of glass and platinum powder, with the glass powder having a grain size several times larger than the platinum powder on the conductive track (2), pressing the end portion of the connection wire (4) into the spot so that the wire will be completely surrounded, and then firing the bonding spot. If the conductive track (2) is applied by film technology, firing of the conductive track (2) and of the bonding spot (3) can be carried out in a single operating step.

Abstract: To permit firing a composite carrier for a printed circuit in which the carrier has a base of metal, typically steel, and thus is highly vibration and bending resistant, the coating or cover layer is a glass ceramic of BaO-Al.sub.2 O.sub.3 -SiO.sub.2, typically 25 to 40%, preferably 35% of BaO, 5 to 20%, preferably 10% Al.sub.2 O.sub.3 and 40 to 65%, preferably about 55% SiO.sub.2. Rather than using 40 to 65% SiO.sub.2, a lesser quantity of SiO.sub.2, e.g., 30 to 65% may be used and then 0 to 15% MgO, 0 to 15% CaO, 0 to 5% SrO, 0 to 2% B.sub.2 O.sub.3, 0 to 4% PbO, 0 to 3% ZnO and 0 to 4% TiO.sub.2 may be applied. The glass ceramic may be dyed, for example by an inorganic dye, such as cobalt silicate, and standard resistor and conductor pastes, such as Cermalloy or Heraprint may be applied and fired at temperatures below 980.degree. C., and entirely suitable for firing temperatures above 850.degree. C. The coating or cover layer has a thickness of above 20 micrometers, preferably of between about 0.03 to 0.