GB991649A - Electrical circuit elements - Google Patents

Abstract

991,649. Resistors; capacitors; circuit assemblies. ELETTRONICA METAL LUX S.p.A. Dec. 21, 1962 [Dec. 27, 1961; Jan. 4, 1962], No. 48358/62. Headings H1M, H1R and H1S. A flat electrical circuit element, e.g. a resistor or capacitor comprises an insulating substrate having an electrically active layer adhering thereto, the connections to the layer being formed by metal strips stuck to the electrically active layer such that the circuit element may be soldered to a printed circuit board without the use of connecting wires. Fig. 2 shows a panel 1 of insulating material, e.g. ceramic or glass, on which has been vapour-deposited a number of strips of resistive material, e.g. nichrome, or other metals, or metallic compounds or alloys; over the resistance material strips are deposited further transverse strips 3 of a good conducting material, such as nickel, silver, gold, iron or copper-manganese compound; over these strips is applied a layer of material, such as gold, which is capable of diffusing under heat into the material of the strip, and a further layer of a readily solderable material such as silver. The plate may be divided by cutting along lines A-A and along lines transverse thereto to form a plurality of resistors as shown in Fig. 4. Before or after separating the resistors the contact strips 3 may have a layer of solder applied to them and the space between the strips covered by a layer of lacquer or varnish. A process for the manufacture of a capacitor comprises vapour depositing on an insulating substrate 12, Fig. 12, layers of conducting material 13 and 14, of e.g. aluminium nickel or gold, these layers are partially covered with a dielectric material 16, e.g. a metal oxide (silicon monoxide), a sulphide (zinc sulphide) or a fluoride (magnesium fluoride), deposited in vacuo from a vapour, or a resin or lacquer having suitable electrical properties. The dielectric material then has a further conducting layer 19 vapour deposited after which connecting strips 20 and 21, Fig. 15, are applied to the exposed edges of the conducting layers 13 and 14 and the centre of the layer 19, strip 20 being a readily diffusable material e.g. gold, and strip 21 a readily solderable material, e.g. silver or gold. The area between the strip 21 is provided with a layer of lacquer or varnish 25 and 26, and the strips 21 are tinned at 27. The plate is then divided down the centre to form a pair of capacitor strips as shown in section in Fig. 18 from which appropriate lengths may be cut to give the desired values of capacitance. A number of the components may be placed in a jig 28, Fig. 19, and a printed wiring board layed over them, located on pegs 32, the assembly being heated by heater 38 so that the components are soldered to the printed wiring board by the solder layer on the component connection strips. Holes 36 and 37 may be provided in the jig to receive inductors, transformers &c.