| 摘要 |
<p>854,881. Coating with metals. ELECTRIC & MUSICAL INDUSTRIES Ltd. Dec. 3, 1957 [Dec. 4, 1956; Feb. 1, 1957], Nos. 36983/56 and 3499/57. Class 82(2) [Also in Group XXXVI] A method of forming a conductive coating on a wall extending into an insulating support comprises providing a covering for the support, apertered to expose the wall, providing a conductive coating which will adhere to the wall, and subsequently removing the covering to leave the conductive coating on the wall in electrical contact with a conductor provided on the support. The wall may be formed either before or after covering. In one embodiment (Fig. 2c), an insulating support 7 having a conductor 8 and an aperture 9, has a rubber mask 10 over its surface which leaves the aperture wall exposed. The wall is first sprayed with an adhesive and then with a thin conductive coating of silver 11 which is used as an electrode for plating a layer of copper 12. The silver coating may be formed by simultaneously spraying a solution of a silver compound e.g. silver nitrate, and a reducing agent. The mask is subsequently removed (Fig. 2d) leaving the portions of the coating 11 and the layer 12 on the aperture wall in electrical contact with the conductor. In other embodiments Figs. 1a to 1c, not shown) the mask may be replaced by a coating, such as wax, shellac or gum and the aperture made after applying this coating. The layer of copper may alternatively be sprayed on to the silver. Specification 854,880 is referred to:</p> |
