| 摘要 |
A printed circuit micro-module functioning as an AND/OR inverter circuit (Fig. 1, not shown) is made by a process comprising the following steps:-(a) A conductive pattern 41, Fig. 10 (not shown), is printed by silk-screening metallizing ink comprising e.g. Au, Ag, Pt, on to a substrate 42 (e.g. of alumina) having apertures 44 around its periphery; then the substrate is fired at c. 750-800 DEG C. for c. 30 minutes to solidify the conductors. (b) Resistor elements 28, 29, 30 are deposited by silk-screening a paste, e.g. a palladium oxide-silver composition, in the desired positions on the substrate 42, dried, then fired at c. 800 DEG C. for c. 50 minutes. (c) Plug pins 62, Fig. 5 (not shown), e.g. of Cu, are inserted in apertures 44 in the substrate and expanded at 63, 64 to secure them in position. (d) The substrate is dip-soldered to effect good electrical connections between pins 62 and conductors 41, and to tin the latter. (e) Resistor values are corrected by cutting notches 71 in resistors 28, 29, 30 by abrasion, burning or grinding, resistance values being measured in an electrical bridge circuit. (f) Transistors and diodes 20, 23, 24, 27 are fastened in position by the process described in Specification 1,013,333. (g) The micro-module is encapsulated by dipping in a plastic material, e.g. silicon varnish. Modifications.-Capacitors 82, 83, 84, Fig. 11 (not shown), are formed by extending Au-Pt conductors 41 to include first capacitor plates 81, adding dielectric layers 85, and finally silk-screening and firing Au-Pt counter electrodes 86. The dielectric may comprise ceramic material such as titanium dioxide and barium titanate with modifiers, e.g. bismuth stannate and calcium stannate, with borosilicate glass as a binder and an organic vehicle such as pine oil to provide the viscosity necessary for silk-screening; the layers are fired at c. 900 DEG C. for c. 2 hours. Inductors such as at 101, Fig. 12 (not shown), may be formed on the reverse side of substrate 42. Half of windings 103 are printed and fired, then an insulating core 102 of glass, which may include a ferrite, is added, followed by the printing of the other half of windings 103. The inductor is connected to the conductive pins by dip-soldering. |
