| 摘要 |
1283960 Anodizing aluminium; electrodepositing silver PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 14 Nov 1969 [19 Nov 1968] 55849/69 Heading C7B [Also in Division H1] A target for a camera tube comprises a semiconductor substrate 14 in which is provided a mosaic of rectifying junction regions 13, and an insulating layer 15 covered by a conductive layer 17, cavities 21 extending through the layers to the regions and extending laterally to below the insulating layer. If the layer 17 is of aluminium it may be provided with an insulating surface by electrolytic anodic oxidation treatment, the electrolyte comprising 5% ammonium pentaborate in glycol, and the electrolytic current being 0.5 mA per sq. cm of the layer 17. In a modification, Fig. 6 (not shown), the cavities are filled with metal such as silver deposited electrolytically, and the metal layer 12 may be removed by etching prior to the deposition of the filling. The electrolyte for silver deposition may comprise 125g KCN, 22À5g K 2 CO 3 , 4.5g KOH and 25g AgCN per litre of water, and the current density may be 5 mA per sq. cm. The rectifying junctions are reversebiased during this process and if this resistance is too great it may be reduced by exposing the junctions through the substrate. |
