| 摘要 |
1,133,402. Resistance films. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 20 March, 1967 [23 March. 1966], No. 12864/67. Heading H1S. An insulating carrier 1 of, e.g. glass has deposited thereon an electrically resistive film 2 formed by evaporating a nickel-chromium alloy, e.g. 80% nickel, 20% chromium by weight, in an atmosphere of oxygen at a pressure in the range from 7 x 10<SP>-6</SP> to 3 x 10<SP>-5</SP> torr until the film has its desired resistance, and an insulating oxide film 3 deposited over the resistive film 2 by continuing evaporation of the nickelchromium alloy under an increased oxygen pressure in the range from 4À5 x 10<SP>-5</SP> to 1À5 x 10<SP>-4</SP> torr, deposition of the insulating layer being such as to have no substantial effect on the resistance of the resistive layer. Before deposition each glass plate is provided with metal contacts, e.g. silver by vapour deposition. During deposition one of a number of substrates is connected to external circuitry to monitor the resistance of the deposited film. The substrates are heated to approximately 300‹ C. during deposition. Resistance films so produced are said to be more stable under heat treatment than films of the prior art and have low temperature coefficients of the order of - 50 p.p.m. per ‹C. |
