| 摘要 |
1,136,752. Printed circuits. ENGLISH ELECTRIC COMPUTERS Ltd. 4 Oct., 1966 [26 Oct., 1965], No. 45362/65. Heading H1R. In a method of making a printed circuit board having a metallic substrate, a metal sheet 5 has an insulating pattern 6A, formed on a surface thereof, which pattern is sealed; a second insulating layer 6B, thicker than 6A, is next formed on the parts of the surface of sheet 5 not covered by pattern 6A. A layer 7A of metal is deposited over the entire surface of layers 6A, 6B, after which the said surface is reduced by grinding down to the plane A-A, so leaving a metal deposit only on the surface of pattern 6A. Preferably sheet 5 comprises, or is coated with, a metal such as Al, Mg, Ti, Be, Zr or alloys thereof, which may be anodized or otherwise oxidized to form the insulating layers; alternatively, the latter may be formed by spraying or evaporating insulating material on to sheet 5. Metal layer 7A may be of Au, Cu or Al, and may be deposited by electroless and electrolytic plating, vacuum or vapour phase deposition, or spraying.
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