Improvements in or relating to the manufacture of electrical component assemblies

摘要

1,113,186. Printed circuits. SIEMENS A.G. 7 March, 1967 [8 March, 1966], No. 10603/67. Heading H1R. In a process for making a thin film circuit comprising at least one resistor and at least one capacitor, one surface of an insulating carrier 1 (e.g. glass or ceramic) is covered with a highresistance metal layer 2; a lower-resistance metal layer 3 is then deposited, followed by etching away of unwanted parts of the layers 2, 3; layer 3 is partially oxidized where resistors and capacitors are required, to produce a capacitor dielectric layer 6 overlying a lowresistance electrode 5; and the areas designed as resistors are further treated so as completely to oxidize at least layer 3 at 4. Where conductors are required, layer 3 is protected from any oxidation. The preferred metal for layers 2, 3 is Ta, the difference in resistivity of the layers being produced at the sputtering-on stage; alternatively, layers 2, 3 may comprise Ta/A1; Ni-Cr/Ta; or Ni-Cr/A1. The oxidation steps are preferably carried out by anodization. A second electrode 7 for the capacitor may be of Au applied by vapour deposition.