Abstract A method of manufacturing a thin film thermistor in which the reagent grade materials are dissolved in water and allowed to intimately mix therein after which the mixture is spray-dried under pressure to obtain a fine powder which is the true thermistor composition desired. After oxidation at high temperatures for a long period of time to remove sulphites etc., the resulting oxides are mixed in a bone milling process with a plastic binder which is then poured on to a glass plate and spread to a predetermined thickness and allowed to dry, after which the material is placed on a ceramic plate and fired to bond the plastic and ceramic and burn out portions of the plastic whereupon electrodes are attached to the final thermistor.
The invention according to claim 1 wherein said organic binder material comprises Bakelite dissolved in methyl alcohol and amyl acetate.
Claim 2
Dependent Claim
23 words
The invention according to claim 1 wherein the compounds dissolved in water consist of magnesium sulphate, cobalt sulphate, copper sulphate and nickel sulphate.
Claim 3
Dependent Claim
40 words
The invention according to claim 2 wherein said compounds consist of 27.2 percent by weight of magnesium sulphate, 61.9 percent by weight of cobalt sulphate, 9.9 percent by weight of copper sulphate and 1 percent by weight of nickel sulphate.
Claim 4
Dependent Claim
23 words
The invention according to claim 1 wherein said solution is spray dried under pressure at the temperature in the range of 500*-700* F.
Claim 5
Dependent Claim
26 words
The invention according to claim 5 wherein said resulting powder is fired at a temperature in the range of 900*C for approximately 24 to 48 hours.
Claim 6
Dependent Claim
18 words
The invention according to claim 1 wherein said thin film is deposited to be approximately 0.0075 inches thick.
Claim 7
Dependent Claim
27 words
The invention according to claim 1 wherein said thin film and substrate is fired for approximately one hour at a temperature in the range of 1250* C.
Claim 8
Dependent Claim
23 words
The invention according to claim 2 wherein a portion of the plastic binder is dissolved when placing said cut film on said substrate.
Claim 9
Dependent Claim
14 words
The invention according to claim 1 wherein said electrodes are attached by vacuum deposition.