| 摘要 |
1,239,824. Printed circuits. THOMSON CSF. 3 July, 1968 [4 July, 1967], No. 31833/68. Heading H1R. [Also in Division H3] A matrix or other magnetic storage arrangement comprises an apertured ferromagnetic plate with printed conductors on the two surfaces and in the apertures, the arrangement being formed from an apertured ferromagnetic plate sandwiched between layers of conductive material, e.g. copper, by electroplating a predetermined pattern of gold conductors which extend through the apertures, and then dissolving away the conductive material and replacing it by an insulating material which supports the pattern of gold conductors remaining. The apertures 2, Fig. 5, may be formed by etching a sandwich structure comprising a ferromagnetic plate 10 and copper layers 20, which is selectively coated with a layer of photosensitive material 40. Selected areas of copper are then bared and used as an anode for electrolytically depositing a pattern of gold conductors 3A as shown in Fig. 7. Total removal of the copper is effected by dissolving, and the web of gold conductors remaining is supported by introducing a fluid photosensitive resin 80, Fig. 9. A further etching process provides enlarged apertures 100, Fig. 2, and optional selective removal of part of the photosensitive resin 80. Modifications include the two stage etching of the apertures to remove the copper and ferromagnetic material in turn, and applying the copper layers after the apertures are formed in the ferromagnetic material. A further modification is the deposition of resin capsules 600, Fig. 15, by photoengraving methods at the location of the apertures to be formed. The remainder of the plate is then built up by depositing metal 200 and the apertures are formed after dissolving the capsules. Another method uses an initially apertured plate which is coated on both surfaces and through the holes with copper, Fig. 12 (not shown). |
